Download Issue 43 - New Concepts in Global Tectonics

New Concepts in Global Tectonics
NEWSLETTER
No. 43, June, 2007
ISSN: 1833-2560
Editor: Dong R. CHOI ([email protected])
www.ncgt.org
Editorial board
Ismail BHAT, India ([email protected]); Peter JAMES, Australia ([email protected]);
Leo MASLOV, USA ([email protected]); Cliff OLLIER, Australia ([email protected]);
Nina PAVLENKOVA, Russia ([email protected]); David PRATT, Netherlands ([email protected]);
Giancarlo SCALERA, Italy ([email protected]); N. Christian SMOOT, USA ([email protected]);
Karsten STOREDVEDT, Norway ([email protected]); Yasumoto SUZUKI, Japan ([email protected]);
Boris I. VASILIEV, Russia ([email protected])
_________________________________________________________________________________________________________
CONTENTS
From the Editor………………………………………………………………………………………….……2
Letters to the Editors..…………………………………………………………………………………….…..2
Articles
Ancient and continental rocks discovered in the ocean floors, Boris I. VASILIEV and Takao YANO…….3
Geological consequences of large meteoric bodies approaching the Earth – The electrical factor,
Konstantin K. KHAZANOVITCH-WULFF……………………………………………………………..18
The great twin earthquakes in late 2006 to early 2007 in the Kuril Arc: their forerunners and the
seismicity-tectonics relationship, Claude BLOT, Dong R. CHOI and Boris I. VASILIEV…………......22
Seimso-electro-magnetic and other precursory observations from recent earthquakes, Arun BAPAT…....34
Solid planetary tides and differential motion of deep layers, Lev A. MASLOV and
Vladimir A. ANOKHIN………………………………………………………………………………….39
Tectonic controls of climate, Cliff OLLIER……………………………………………………..……..…..46
Short Notes
Global shear deformations, Howard F. DE KALB………………………………………………....…...….56
South American Pacific margin as key target for geosciences and general culture,
Giancarlo SCALERA............................................................................................................................................60
Comments and Replies
More on isostasy: Quantitative evaluation, Peter JAMES……………………….…………………….…..69
Earthquake vapour clouds, Arun BAPAT and Zhonghao SHOU………………………….……….….…...71
Publications
International Geological-Geophysical Atlas of the Pacific Ocean, Boris I. VASILIEV…………..…..……76
Book review
The great dinosaur extinction controversy by C. Officer and J. Page, Chris SMOOT………….….….…..78
News………………………………………………………………………………………………….………80
Financial support and About the Newsletter………………………………………………………….………81
For contact, correspondence, or inclusion of material in the Newsletter please use the following methods: NEW CONCEPTS
IN GLOBAL TECTONICS. 1. E-mail: [email protected], [email protected], or [email protected], each file less than 5
megabytes; 2. Fax (small amount of material): +61-2-6254 4409; 3. Mail, air express, etc., 6 Mann Place, Higgins, ACT 2615,
Australia (files in MS Word format, and figures in jpg or tif format); 4. Telephone, +61-2-6254 4409. DISCLAIMER: The
opinions, observations and ideas published in this newsletter are the responsibility of the contributors and are not necessary those
of the Editor and the Editorial Board. NCGT Newsletter is a quarterly international online journal and appears in March, June,
September and December. Annual subscription fees: electronic format - U$30 for individuals, U$50 for libraries. Hard copy U$50 for individuals, U$70 for libraries. For more details see page 81.
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
FROM THE EDITOR
W
e are pleased to launch a professionally designed NCGT webpage from this issue. You will have noticed the new
format of the cover page with a logo as well as a single-column page format. Financial support for this upgrade was
provided by INGV, Italy, and the logo was designed by Encode Polymedia, a website designer and host based in
Canberra. We thank those who participated in the logo competition with their attractive designs. The new website is more
functional and easy to use. We are going to upgrade several minor areas of the site in near future to improve readers’
convenience. We welcome your feedback on any aspects of the new site or the NCGT group in general.
This number has become the largest in NCGT’s history: it is full of interesting, exciting and high-quality articles. The
Vasiliev and Yano paper must be read by all geological and geophysical communities who deal with global tectonics.
They document ancient continental rocks so far discovered in the world ocean floors; their pervasive presence is quite
overwhelming. The plain truth described in this paper must be given priority consideration in building any Earth
geodynamic hypotheses. Blot et al. continue to analyse the seismicity-tectonics relationship – this time the twin
earthquakes off Kuril Arc in late 2006 to early 2007. Bapat, mainly based on seismo-electro-magnetic precursors,
considers that strong earthquakes are predictable despite the fact that the majority of authoritative earthquake institutions
(which use plate tectonics as their tectonic model) think otherwise; this is in good harmony with the Shou’s earthquake
vapour cloud and Blot’s energy transmigration concepts as well as geological and geophysical observations of the WadatiBenioff zone by some of NCGT members.
In addition to the above, we have a very inspiring paper by Khazanovitch-Wulff on the possible electric effect of
approaching meteorite bodies on the Earth’s tectonic phenomena. Maslov and Anokhin analyse the planetary tide and its
influence on the deep Earth layers. We have another important paper on the subject of climate and tectonics, this one by
Ollier. This issue also includes the first part of De Kalb’s paper on the global shear deformations, and Scalera’s proposal
for the systematic geophysical study of the South American Pacific margins because of their peculiar geophysical
phenomena and events.
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LETTERS TO THE EDITORS
Dear Prof. Cliff OLLIER,
Y
ou must know above all that, having reached the age of 86, I retired from all geological activities more than 10 years
ago, and that geology has thus become for me merely one hobby among many others. I am thus no longer up-to-date
with recent developments in our science. Nevertheless, I remain interested in new ideas concerning global tectonics by
occasionally reading articles on this subject which I happen to come across. It was in this way that my attention was
drawn to your contributions in the last issue of Annals of Geophysics (C. Ollier, 2003. Mountain Uplift and Neotectonic
Period, v. 49, p. 437-450).
I also read the two printed attachments to your letter. With regard to isostasy, you may be interested in what I mentioned a
long time ago concerning the steep attitude of the Himalayan Main Boundary Thrust (MBT) in an article on the geology
of Nepal. I quote (from p. 26 in J. Geol. Soc. London, v. 137, 1980):
"... steepening of the MBT was concomitant with the formation of the Mahabharat synclinorium. It may have been
produced either by continued horizontal stress or, as may be suggested, by crustal down-warping as an isostatic response
to up-thrusting and erosional isolation of the Mahabharat Range." (The Mahabharat Synclinorium coincides with an
erosionally isolated crystalline thrust mass forming the highest portion of the Lesser Himalayan Mahabharat Range in the
Kathmandu sector).
From this you may also see that the erosion/creep/isostatic uplift interrelations, which seem to be a fundamental aspect in
your ideas of mountain building, make your book of quite some interest to me.
Jovan Stoecklin
[email protected]
5 January, 2007
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
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ARTICLES
ANCIENT AND CONTINENTAL ROCKS DISCOVERED
IN THE OCEAN FLOORS
Boris I. VASILIEV
V.I. Il’ichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences,
Vladivostok, 690041, Russia
[email protected]
Takao YANO
Department of Environmental Science, Faculty of Regional Sciences,
Tottori University, Tottori 680-8551, Japan
[email protected]
(Editor’s note: This article is a translation of a paper by the above authors which appeared in the Journal of Science
Education, Japan, v. 49, no. 7, p. 25-41, 2006, by permission from Hoshinowakai. Abstract was added by the authors.
Translation from Japanese into English by Dong R. Choi and David Pratt)
Abstract: According to the hypothesis of ocean-floor spreading, oceanic crust contains no rocks older than 200 Ma and of
continental origin. The Atlantic, Indian and Pacific oceanic crusts, however, include rocks dating back to 2.55 Ga and of
continental constituents, such as granitoids, gneisses, schists, granulites, and coarse-grained terrigenous clastics. These rocks
have evoked ad hoc modifications to the hypothesis, e.g., ridge jumping, transform migration, oscillatory spreading, ridge
propagation, small-scale, roll-like, flat, slower-circulating convection in the asthenosphere beneath spreading centers, nonspreading areas, etc. Consequently the hypothesis is losing its original simplicity and internal logical consistency. These
ancient continental rocks should be understood to suggest, instead, that the basic premises of the sea-floor spreading
hypothesis, as well as of plate tectonics, must be re-examined. Because the old continental rocks already found have been
discovered only by accident, future drillings and dredgings will likely prove the systematic presence of ancient continental
rocks in the world oceans. Several target areas for future deep-sea drillings are proposed for the Pacific.
Keywords: ancient rocks, continental rocks, Atlantic Ocean, Indian Ocean, Pacific Ocean
1. Introduction
T
he movement of the Earth’s surface is commonly explained by plate tectonics. This hypothesis is treated as a
“proven theory” not only in research organizations, but also in high-school textbooks and even in university
entrance examinations.
According to plate tectonics, the Earth’s surface is covered by ten or more solid plates. They move relative to each
other at a speed of 1 to 10 cm/year without deformation. There are four forms of relative plate movement: spreading,
collision, subduction (one of the plates), and sliding past one another.
Despite starting with these simple tenets, however, plate tectonics has become increasingly complex to explain away
conflicting observations. Plates have constantly been subdivided, resulting in some that are only a few hundred
kilometers in size, and special, localized movements have had to be invoked. If a diachronous, worldwide compilation
of the vast number of studies was made, the resulting reconstruction of the Earth’s history would probably be more
complicated than the Ptolemy’s model of planetary motions in terms of epicycles and deferents.
Facts observed in the field are exciting and interesting, but it seems that a grand theory embracing all of them will take
much more time to be formulated. In this paper we would like to present evidence for an emerging new geodynamic
paradigm.
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 1. Model for the formation of oceanic plates at a mid-oceanic ridge (modified from Dewey and Bird, 1970).
2. Origin of oceanic plates
Plate tectonics explains the formation of oceanic plates as follows (Fig. 1): A mid-oceanic ridge is the boundary of two
separating plates, where magma rises from depth into the space formed by the spreading plates. When cooled and
hardened, a new oceanic crust is formed. The repetition of this process produces the expansion of oceanic floors. Old
oceanic crusts sink under continents or island arcs at subsiding boundaries or trenches. Therefore, the seafloors are
constantly renewed and can be no older than 200 million years.
In many mid-oceanic ridges there are axial grabens offset by fracture zones (Fig. 1). Under the mid-oceanic ridge, the
mantle materials rising adiabatically reach the state of 20 to 30% partial melting. The magma gathered by this melt
rises further, and forms a basaltic magma chamber directly beneath the mid-oceanic ridge. The magma penetrates and
erupts and becomes basalt. During this process crystallized portions sink to the bottom of a magma chamber to form
cumulate gabbro or peridotite. The surface of the basalt is covered by deep-sea sediments (5 microns or smaller –
pelagic clay or ooze with planktonic remains). Therefore, the oceanic crust consists of deep-sea sediment and basaltic
rocks, and is not supposed to contain any type of continental rocks, such as granite, metamorphic rock and terrigenous
detritus.
However, field data show numerous irregularities. Uyeda (1983) expressed: “The biggest problem of plate tectonics is
the ancient rocks and continental rocks coming from mid-oceanic ridges and ocean floors. If all of them are explained
by ice-rafting, there are no problems, but the reality is not so.” If ancient and continental rocks are actually present, the
simplistic plate-tectonic explanation faces a serious challenge.
In the following pages, we give examples of continental and ancient rocks discovered in the Atlantic, Indian and
Pacific Oceans.
3. Atlantic Ocean
The Atlantic Ocean has been claimed to have formed by the rift of the western part of Pangaea in an east-west
direction. However, the actual data show that continental and ancient rocks have been discovered at over 40 locations
(Fig. 2).
Some of the rocks may be ice-rafted or ship ballast, but the seventeen localities in Fig. 2 produced continental rocks
obtained by drilling or dredging from the sea bed – they are undoubtedly of local and in-situ origin.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 2. Ancient and continental rocks in the Atlantic (compiled from Rezanov, 2000, and various sources).
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 3. Northern Atlantic part of “Geological Map of the World” (Jatskevich [ed.], 2000). J: Jan Mayen Ridge, V: Vøring
Plateau, R: Rockall Plateau, A-B: profile line of Fig. 4.
(1) Northern North Atlantic Ocean
In the northern part of the North Atlantic, continental rocks develop in various places. The Rockall Plateau on the
European side (R: Precambrian, pink), Vøring Plateau (V: Middle-Late Paleozoic overlain by Cenozoic, yellow) and its
southern area (K2: Upper Cretaceous, yellow green), and Jan Mayen Ridge (J: Mesozoic and Late Paleozoic, green and
greenish brown).
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
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Figure 4. Sketch of seismic profile across the Jan Mayen Ridge (Talwani and Udintsev, 1976). See Fig. 3 for profile line.
The Jan Mayen Ridge is a fault block 100-150 km wide and 500 km long (Fig. 4; Talwani and Udintsev, 1976). The
top of the ridge is covered by pelagic sediment (120 m thick, but not distinguishable in the profile due to its extreme
thinness). Below the surface pelagic sediment there is a sedimentary layer which is dipping eastward in conformity
with seismic velocity structure underneath. The clino-unconformity at the base of the pelagic sediment was formed by
subaerial erosion; directly below the unconformity Late Eocene-Early Oligocene terrigenous rocks (sandy siltstone and
sandstone) have been recovered by drilling – therefore, the thick sediments beneath the Late Eocene were postulated to
be Mesozoic to Paleozoic.
According to the structural exploration data, the ridge is continental. A recently published geological map and profile
by Sigmond (2002) showed eastward-dipping Mesozoic (Cretaceous-Triassic), Paleozoic (Permian-Devonian), and
Pre-Devonian continental crust.
The microcontinent at the Jan Mayen Ridge has been explained by Talwani and Udintsev (1976) and Gudlaugsson et
al. (1988) as follows: This microcontinent was a shallow-water region fringing the Greenland until the Early
Oligocene, which received terrigenous sediments from neighbouring land. The then mid-oceanic ridge was located in
the middle between nearshore Greenland and the European continent. But due to the westward jump of the mid-oceanic
ridge in the Late Oligocene, a new continental breakup took place 100 - 150 km inside the coastal line of the Greenland
at that time, resulting in the formation of a microcontinent. In the breakup space the Mid-Atlantic Ridge appeared, and
then the microcontinents moved eastward by the subsequent ocean-floor spreading.
The origin of the Jan Mayen Ridge was explained by the jumping of the mid-oceanic ridge, but no clear mechanism for
this has been presented. Moreover, the jump occurred only in that 1,000 km-long segment of the entire Mid-Atlantic
Ridge. This is a classic illustration that whenever a new microcontinent is discovered, plate movement becomes more
complex.
(2) Equatorial Atlantic
In the Equatorial Atlantic there are numerous large-scale fracture zones which make the Mid-Atlantic Ridge
discontinuous and complex in form. In this region, the following in-situ ancient and continental rocks have been
reported (Fig. 5).
1) Gabbro with zircons of old age (Fig. 5-a).
About 5-35 km south of the Kane Fracture Zone, peridotite and gabbro have been found from the western wall of the
central valley of the Mid-Atlantic Ridge. Many zircons were included in gabbro which was recovered from a deep-sea
drilling. Pilot et al. (1998), based on three different isotope age determination methods, identified two age groups in the
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
zircons: 330 Ma (Paleozoic) and 1,600 Ma (Proterozoic). They explained the old age of the zircons as follows: When
Gondwanaland started to break about 200 million years ago, fragments of continental crust consisting of ProterozoicPaleozoic rocks were caught by small-scale, roll-like, flat, slower-circulating convection cells that were formed in the
shallow part of the mantle on both sides of the mid-oceanic ridge or by the non-spreading area in the uppermost mantle,
and stayed in the same place for a long time. The continental fragments were warmed and melted in the mantle. But the
portions that did not melt were absorbed in the cooling gabbro in the magma chamber. The gabbro was then uplifted to
form the western wall of the central valley.
To explain away the ancient rocks discovered in the mid-oceanic ridge, plate tectonicists have had to invent new
concepts, such as small-scale, roll-like convection or non-spreading areas. It is not clear what mechanism supposedly
produced such a stagnancy or non-spreading in a mobile environment, as well as prevented the continental fragments
from melting for a long period despite the fact that continental fragments are considered to melt at a lower temperature
than basalt.
2) Ancient limestones (Fig. 5-b)
In the south of the Vema Fracture Zone there is a linear rise (20 km wide and over 400 km long), known as the Vema
Transverse Ridge (Bonatti and Cane, 1982). The ridge is covered by pelagic carbonates of Cretaceous-Early Paleocene
age. These ages are 30 million years older than the predicted seafloor age (Miocene). The depth of the ridge is 4,000 m
shallower than predicted by the theoretical subsidence curve. The ridge top is capped with shallow-water reefal
carbonates, subaerially exposed from the late Miocene to the mid-Pliocene.
Bonatti and Crane (1982) tried to explain the formation of the ridge by assuming its anti-clockwise rotation by 10-15
degrees and its accompanying crustal movement, such as change and reversal of the moving direction of the crustal
slices, oscillatory seafloor spreading, and rise of the crustal slices by local compressional force. They insisted on the
necessity of a more detailed study to evaluate the mechanism of local rotation and complex movement of the midoceanic ridge.
3) Ancient continental peridotites (Fig. 5-c)
St. Paul’s Rock is a small reef situated just north of the equator. The reef is the northern wall of the St. Paul Fracture
Zone. It is a subaerial exposure of the raised part of the Fracture Zone. Charles Darwin, during the voyage on the
Beagle in 1831, noticed that the reef was not a normal volcanic island. Strangely, these rocks showed a metasomatic
isotope age of 1,550 Ma, although they are located less than 200 km from the mid-oceanic ridge (Roden et al., 1984).
Moreover, the chemical and isotope compositions are largely different from those of the mantle under the mid-oceanic
ridge, and show affinity with the mantle under a continental rift.
Based on these facts, the origin of St. Paul’s Rock was explained as a fragment of upper mantle beneath continent that
had been broken while rifting and had stayed near the mid-oceanic ridge for over 100 million years. The mechanisms
proposed by plate tectonics – transform migration, oscillatory seafloor spreading – are not very convincing.
4) Old sedimentary rocks (Fig. 5-d & -e)
According to Bonatti et al. (1996), in the northern wall of the Romanche Fracture Zone (Fig. 5-4) there are thick
sedimentary layers (over 4 km). The lower part of the sedimentary layer consists of Lower Cretaceous (about 140 Ma)
pelagic limestone, which is much older than the nearby Paleogene oceanic crust (about 55 Ma). The upper part of the
sedimentary unit includes quartz silt and biomicrite (sand-sized organic fragments in lime-mud matrix). The angular
quartz grains (100 -200μm) prove the presence of granitic continental rocks near the site. Similar siltstone develops
off Africa (Fig. 5-e).
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
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Figure 5. Ancient and continental rocks in the Equatorial Atlantic. See Fig. 2 for location. Ocean floor ages from Dercourt
(2000).
These mysterious sedimentary layers are present along the Romanche Fracture Zone. To explain them Bonatti et al.
(1996) invoked a complex mechanism involving a jump of the mid-oceanic ridge, oscillatory seafloor spreading, and
vertical movement – instead of the simple plate-tectonic movement.
4. Indian Ocean
The Indian Ocean is generally believed to have been formed by the breakup of the southern part of the Pangaea
Supercontinent and subsequent seafloor spreading. India and Australia were separated from Antarctica and moved
northward. India became part of Asia by “colliding” with the Eurasian continent. The Australian continent is said to be
still moving north.
There are three mid-oceanic ridges in the Indian Ocean – the Central Indian Ridge, SE Indian Ridge and SW Indian
Ridge. They are joined together in the middle of the Indian Ocean (Fig. 6). Furthermore, the seafloor has a complex
morphology, with many rises, plateaus, and ridges.
(1) Ridges and plateaus
Plateaus and ridges which rise from the 4,000 to 5,000 m-deep seafloor are block faulted and have varying surface
depth. Vertical offset of some faults often reaches over 1,000 m. The rises generally have larger crustal thicknesses (10
to 15 km), which is two to three times the normal oceanic crust. In the north of Seychelles Plateau the crust is 33 km
thick, comparable with normal continental crust. Because the plateaus and ridges are covered by Cretaceous-Cenozoic
basalt, it is difficult to judge whether the rises are of volcanic origin or microcontinents in many cases. However, many
plateaus and ridges off Africa are considered to be underlain by continental crust – as in the case of Madagascar.
(2) Continental rocks
In the Indian Ocean, six sites of plateaus and ridges yielded continental rocks, twelve sites had volcanic rocks with
geochemical anomalies (i.e. contamination with continental materials), and three sites yielded coarse terrigenous
sediments.
1) Granite and gneiss (Fig. 6, stars)
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Coral reefs cover the Seychelles Islands. Twenty-five of them are underlain by Late Proterozoic granites (800 to 700
million years old), according to Ashwal et al. (2002).
On the Agulhas Plateau off Africa, metamorphic rocks which typically form continents (crystalline schist, gneiss and
granulite) have been dredged (Udintsev, 1990). Their isotope ages indicated they were 1,000 to 600-450 million years
old.
Granite and gneiss have been dredged from the Naturaliste Plateau, located southwest of Australia (Gladczenko, 2001).
2) Volcanic rocks showing geochemical anomalies (Fig. 6, squares)
The composition of isotopes (such as strontium, neodymium and lead) in Indian Ocean basalts is largely different from
that in the Pacific and Atlantic Oceans (Weis et al., 2001). The primary cause of this difference is sought to varying
degrees in a mixture of continental materials (continental crust or continental lithosphere) into the mantle which
supplied basaltic magmas. Such geochemical anomalies are recognized in mid-oceanic ridges as well as plateaus and
ridges. Weis et al. (2001) considered that continental materials are widely dispersed in the lithosphere and
asthenosphere under the Indian Ocean.
In addition, at the Elan Bank projecting southwestward in the Kerguellen Plateau conglomerate was recovered from a
drill hole (Fig. 7). The conglomerate had rhyolite and trachyte gravels. Isotopic analysis of these rocks showed that
they were derived from the partial melting of continental crust (Ingle et al., 2002).
3) Coarse-grained sediment (Fig. 6, filled circles)
A reflection seismic profile in the Somali basin, in the northwestern Indian Ocean, showed a sedimentary layer several
kilometres thick. Deep-sea drilling resulted in the discovery of Eocene-Upper Cretaceous quartz sandstone (with grains
of garnet, tourmaline, etc.) and siltstone (Shipboard Scientific Party, 1977). This sedimentary layer thickens westward,
and therefore it is considered deep-sea turbidites from Africa. The undrilled section beneath the Cretaceous was
postulated to include Jurassic. The Late Cretaceous-Eocene basaltic flows on the Comores Islands include quartz
sandstone xenoliths (maximum diameter, 30 cm) (Flower and Strong, 1969), implying the presence of terrigenous
coarse-grained sediment under the basalt.
The deep-sea drillings on the Kerguelen Plateau in the southern Indian Ocean showed that almost all the basalts flowed
subaerially (Frey et al., 2003). Wood fragments and fern fossils were discovered in sedimentary rocks intercalated in
basaltic lavas. From the Elan Bank of the Kerguelen Plateau, a drill hole recovered fluvial conglomerate (26 m thick),
Fig. 7, which was sandwiched between Cretaceous terrestrial basaltic lavas. The gravels are several centimetres in
diameter, and composed of alkaline basalt, rhyolite, trachyte, granitoid, and garnet gneiss (Ingle et al., 2002). Zircons
and monazites in sands which fill the gravels were dated as 2.55 Ga (Latest Archean) and 550 Ma (Proterozoic). These
conglomerates testify that a gravelly river had existed on the Elan Bank in the Cretaceous and that the gravels were
derived from an exposed Precambrian land consisting of granite and gneiss.
(3) Subsidence of plateaus and ridges
According to Udintsev (1990), sedimentary covers in the Indian Ocean record that many plateaus and ridges had
undergone relatively rapid deepening in Cretaceous-Miocene time, particularly in the Paleogene. During this process,
block faulting prevailed, and each block being subjected to a different rate and timing of subsidence and degree of
inclination, to form a complex block-geomorphic structure as seen today.
For example, the deepening process of the Kerguelen Plateau was reconstructed as seen in the A-B profile, Fig. 8
(Shipboard Scientific Party, 1989): (1) The fault block movement started in the early Late Cretaceous in a subaerial
environment. Basalt flows repeatedly covered the plateau. (2) Marine transgression occurred in the latest Late
Cretaceous-Eocene time, and subsiding blocks were covered by seawater, resulting in the deposition of shallow-water
sediments on the broad shelf. (3) After the Miocene, as the climate cooled, diatomaceous ooze was deposited, as well
as dropstones carried by icebergs.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
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Figure 6. Ancient and continental rocks in the Indian Ocean (compiled from various sources).
Figure 7. Conglomerate core drilled at the Elan Bank (ODP Site 1137A) of the Kerguelen Plateau (Frey et al., 2003).
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Taking a more regional view of the Kerguelen Plateau, a broad land (2,000 x 400 km) has subsided to the current depth
of 1,000 to 2,000 m. The area which deepened most is the Labuan basin, which is now 4,500 m deep. Gneiss and
granite (1 – 0.5 Ga) cropped out in this basin (Gladczenko, 2001), proving that continental crust exists underneath. This
fact may imply the oceanization of continental crust as proposed by Beloussov (1960).
Other plateaus and ridges in the Indian Ocean have not been studied well in terms of their subsidence and deepening
mechanism. If they are remnants of old continents, the subsidence and deepening which accompanied violent basaltic
activities could be the cause of geochemical anomalies characterized by contaminated continental materials as
postulated by Weis et al. (2001).
5. Pacific Ocean
According to plate tectonics, the Pacific Ocean was formed by the breakup of the 600 to 700 million year-old
Gondwanaland, which is one generation older than Pangaea (300 to 200 million years). The post-breakup history is
characterized by ocean-floor spreading and subduction, which renewed the oceanic crust continuously. Therefore, no
ancient, continental rocks older than 200 million years are supposed to be present under the Pacific Ocean.
However, the fact is that ancient continental rocks have been found in many places in the Pacific (Fig. 9). Some
representative cases are as follows:
(1) Kuril-Kamchatka seaward trench slope (Fig. 9-A)
This is one of the regions of the Pacific that have been studied most intensively, by dredging and seismic investigation.
Pillow basaltic lavas intruded by dolerite and gabbro are the most predominant rock type in the region. There is a faultblocked rise near the trench: dredgings have recovered copious garnet-mica schist and phyllitic slate from the rise. The
seaward slope of the Kuril-Kamchatka trench is underlain by metamorphic and sedimentary rocks covered by pillow
basalt (Vasiliev, 1977).
(2) Cusp between Ogasawara Ridge and Ogasawara Plateau (Fig. 9-B)
An E-W rise (3,000 m at the deepest portion) separates the Ogasawara Trench in the north and the northern Mariana
Trench (Volcano Trench) in the south. The area was the site where the most intensive dredging campaign was made by
Vasiliev (1988). He recovered basaltic (pillow) lava and mafic-ultramafic intrusive, as well as crystalline schist. The
crystalline schist is composed of mafic schist (basaltic origin) and garnet siliceous schist (acidic volcanic rock origin),
both of which are the products of metamorphism in continental to continental-margin settings.
(3) Eastern equatorial Pacific (Fig. 9-D, shaded)
In the wide region between the Clarion and Clippertone Fracture Zones in the eastern equatorial Pacific, detailed
seismic and dredging surveys have been made by Tabunov et al. (1989). The study revealed that the seafloor in the
region consists of the following three rock groups:
1) Granite-gneiss group
Granitic gneiss, gneiss, granulite, crystalline schist and amphibolite. Although the ages of these rocks have not been
determined, some of them are likely to be Precambrian.
2) Geosynclinal sedimentary rock group
Conglomerate, tuff, sandstone and claystone. They are considered to be of Mesozoic age. They are intruded by
granodiorite and diorite.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
13
Figure 8. Subsiding process of the Kerguelen Plateau (modified from Shipboard Scientific Party, 1989). With respect to the Late
Cretaceous environment, recent deep-sea drilling (Frey et al., 2003) replaced the originally-interpreted shallow marine environment
with a subaerial environment.
14
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 9. Bathymetric features of the Pacific Ocean.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
15
3) Volcanic rock group
Pre-Eocene basalt, Eocene-Miocene basalt, andesite and rhyolite.
These three groups testify to the fact that the region is underlain by ancient continental basement under the thick
terrigenous sediments.
(4) Eltanin Fracture Zone (Fig. 9-F)
The Eltanin Fracture Zone in the SW Pacific occupies the boundary between the East Pacific Rise and the PacificAntarctica Rise. Its total extension is 7,200 km, one of the longest fracture zones on the globe. The Heezen Fracture
Zone, a component of the Eltanin F.Z., is situated near the northern margin of the axis of the Pacific-Antarctica Ridge,
and forms a giant slope tilting northeastward.
Three hundred kilometers northwest of the northeastern edge of the Pacific-Antarctica Ridge, Fig. 9-F, the angle of the
giant slope averages almost 40 degrees, with a height of 5,500 m (Fig. 10). The seven dredgings on this slope proved
that the profile of the oceanic crust crops out there. The oceanic crust is composed of crystalline schists and maficultramafic rocks; amphibolite, pyroxene-plagioclase schist, peridotite, gabbro, and basalt-dolerite, in ascending order.
The top of the slope is capped unconformably with Cretaceous reefal limestone.
As stated above, the geology disclosed by dredgings indicates that, though located near the Pacific-Antarctica oceanic
ridge, 1) pre-Cretaceous basement rocks are present, and 2) the ancient rocks include continental crystalline schists.
6. Proposed priority drilling sites in the Pacific
We have surveyed the ancient and continental rocks discovered in the Atlantic, Indian and Pacific Oceans in the
foregoing pages. In many cases the sites where ancient rocks are discovered are fracture zones, mid-oceanic ridges, and
the slopes of plateaus and ridges. They are usually the places where the deep section of the oceanic crust was exposed
to the seafloor. Therefore, if much deeper drillings are made, it is possible that more ancient continental rocks will be
encountered even under the deep-sea floor, and plateaus and ridges covered by deep-sea sediments or basalt.
The increased discovery of ancient continental rocks will force the seafloor spreading theory to become more complex,
until it eventually becomes scientifically untenable, leading to the birth of a new, more comprehensive, global tectonic
theory, which can embrace the presence of ancient continental rocks under the ocean floor. In any case, it is essential to
fully understand the geology of the oceans, which occupy two thirds of the Earth’s surface, to establish a workable
geodynamic hypothesis of the solid Earth.
One of the major objectives of future deep-sea drilling should be to clarify the composition, geological structure and
age of the basement rocks. In the Pacific Ocean, the following five regions are considered of high priority.
1) Equatorial Pacific
In the area between the Clarion and Clipperton Fracture Zones (Fig. 9-D), numerous dredgings recovered ancient
continental rocks, as mentioned earlier (Tabunov et al., 1989). They are expected to underlie the seafloor and at a
relatively shallow depth. The region suitable for drilling is a rectangular area surrounded by two diagonal points, 18o
o
o
o
10 N, 145 W and 19-20 N, 140 W. Three to five sites should be drilled to a depth of 800 to 1,000 m.
2) Eastern slope of the East Pacific Rise near Easter Island (Fig. 9-E)
Based on dredging data the region is widely occupied by high alkaline volcanic rocks (pantelleritic rhyolite and highpotassium basalt), whose geochemical composition resembles that of continental flood basalts (Krendelev, 1976). The
region is expected to have remnants of continental rocks. Two or three sites should be drilled to a depth of 800 to 1,000
m.
16
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
3) Mid-Pacific Mountains (Fig. 9-C)
According to the dredgings and drillings in this seamount group, the area has an ankaramite-trachytic basalt series. This
assemblage is characteristic of ancient continental crust (Govorov et al., 1993). Drilling should take place at the top of
guyots or atoll reefs, to a depth of 800 to 1,000 m.
4) Volcano Trench (Fig. 9-B)
The seaward slope of volcanic trenches consists of highly differentiated volcanic rocks – basalts and trachytes-trachytic
rhyolites. An acidic rock with over 72% of SiO content implies the presence of continental rocks (Vasiliev, 1988). The
2
site recommended is at 24o 30’N, 144oE (water depth 5,500 m). The subsurface depth needs to reach 1,000 m.
5) Kuril-Kamchatka Trench
Based on detailed geological and geophysical data (Vasiliev, 1977), the following two sites are suggested:
o
o
o
o
Site 1. (42 00’E, 146 45’E, depth 7,000 m, drilling depth 1,000 – 1,600 m)
The site is in the trench. The aim is to clarify the primary features of the junction of the ocean and the continent.
Site 2. (44 50’N, 148 58’E, water depth 5,500 m, drilling depth 1,000 m)
The site is on a small anticline in the landward slope of the trench. Dredging in the region recovered ancient
metamorphic rocks, volcanics and alkaline intrusives. The drilling will reveal the structural development at the oceancontinental boundary.
Figure 10. Geologic profile across the Heezen Fracture of the Eltanin Fracture Zone
Acknowlegements: We sincerely thank Yuko Kuriyama (Hoshinowakai) for permission to reproduce the article, and Dong
R. Choi and David Pratt for their translation and encouragement, as well as Kanji Sato and Ivan V. Yugov for their
procedural supports. Several figures are reproduced according to the applicable permission systems.
References
Ashwal, L.D., Demaiffe, D. and Torsvik, T.H. (2002). Petrogenesis of Neoproterozoic granitoids and related rocks from the
Seychelles: the case for an Andean-type arc origin. Jour. Petrol., v. 43, p. 45-83.
Beloussov, V.V. (1960). Tectonic map of the Earth. Geol. Rundshau, v. 50, p. 316-324.
Bonatti, E. (1990). Subcontinental mantle exposed in the Atlantic Ocean on St. Peter-Paul islets. Nature, v. 345, p. 800-802.
Bonatti, E. and Crane, K. (1982). Oscillatory spreading explanation of anomalously old uplifted crust near oceanic
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
17
transforms. Nature, v. 300, p. 343-345.
Bonatti, E., Ligi, M., Borsetti, A.M., Gasperini L., Negri, A. and Sartori R. (1996). Lower Cretaceous deposits trapped near
the equatorial Mid-Atlantic Ridge. Nature, v. 380, p. 518-520.
Dercourt, J. [ed] (2000). Geological map of the World. Scale 1:25,000,000. Commission for the Geological Map of the
World and UNESCO.
Dewey, J.F. and Bird, J.M. (1970). Mountain belts and the new global tectonics. Journal of Geophysical Research, v. 75,
p. 2625-2646.
Flower, M.F.J. and Strong, D.F. (1969). The significance of sandstone inclusions in lavas of the Comores archiperago. Earth
Planet. Sci. Lett., v. 7, p. 47-50.
Frey, F.A., Coffin, M.F., Wallance, P.J. and Weis, D. (2003). Leg 183 Synthesis: Kerguelen plateau-Broken ridge-a large
igneous province. Proc. Ocean Drilling Program, Scientific Results, v. 183, p. 1-40.
Gladczenko, T.P. (2001). Kerguelen plateau crustal structure and basin formation from seismic and gravity data. Jour.
Geophys. Res., v. 106, p. 16,583-16,601.
Govorov, I.N., Govorov, G.N., Simanenko, V.P.and Martynov Yu.A. (1993). Ankaramite association of Markus-Wake
mountains (Pacific Ocean) as indicator of buried structures. Geotectonics, v. 4, p. 87-96.
Gudlaugsson, S.T., Gunnarsson, K., Sand, M. and Skogseid, J. (1988). Tectonic and volcanic events at the Jan Mayen Ridge
microcontinent. Geol. Soc. Spec. Publ. London, no. 39, p. 85-94.
Ingle, S., Weis, D., Scoates, J. and Frey, F. (2002). Indian continental crust sampled as pebbles within Elan Bank, Kerguelen
Plateau (ODP Leg 183, Site 1137). Jour. Petrol., v. 43, p. 1241-1258.
Jatskevich, B.A. [ed] (2000). Geologic map of the World. Scale 1:15,000,000. Ministry of Natural Resources of the Russian
Federation.
Krendel, F.L. (1976). Easter Island (geology and problems). 136 p. Science, Novosibirsk.
Rezanov, I.A. (2002). Origin of oceanic crust. Bulletin of Moscow Society for Experiment of Nature, Section of Geology,
v. 77, no. 1, 24-31 (in Russian with English abstract).
Roden, M.K., Hart, S.R., Frey, F.A. and Melson, W.G. (1984). Sr, Nd and Pb isotopic and REE geochemistry of St. Paul’s
Rocks: the metamorphic and metasomatic development of an alkali basalt mantle source. Contr. Mineral. Petrol., v. 85,
p. 376-390.
Sigmond, E. M.-O. (2002). Geological Map, Land and Sea Areas of Northern Europe, Scale 1:4 million. Geological Survey
of Norway.
Tabunov, S.M., Tomanovskaya, Yu.I. and Staritsyna, G.N. (1989). Rock complex of the Pacific Ocean bed in the area of
Clarion and Clipperton faults. Pacific Geology, v. 4, p. 11-20.
Talwani, M. and Udintsev, G. (1976). Tectonic synthesis. Initial Reports of the Deep Sea Drilling Project, v. 38,
p. 1213-1242.
The Shipboard Scientific Party (1977). Site 241. DSDP Init. Repts., v. 25，p. 87-107.
Udintsev, G.B. (1990). Geomorphology and geologic structure of ocean floor. Translated and edited by Oshide, K., Hanada,
M. and Ishida, M., GRC-publication/3, 143 p., Research Center of Geo-science, Tsurugashima. [in Japanese]
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[in Japanese]
Vasiliev, B.I. [Responsible Executor] (1988). Results of geological-geophysical researches for the choice of boreholes
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Vasiliev, B.I. (1988). Basic features of the geological structure of the NW Pacific. 192 p., Vladivostok.
18
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
GEOLOGICAL CONSEQUENCES OF LARGE METEORIC BODIES
APPROACHING THE EARTH – THE ELECTRICAL FACTOR
Konstantin K. KHAZANOVITCH-WULFF
Planetology Branch of the Russian Geographical Society,
10 Grivtsov Per., St. Petersburg, 191000, RUSSIA.
E-mail: [email protected]
Abstract: Kimberlite genesis is linked to disruptions in the Earth’s electrical field caused by the approach of large
meteoritic bodies, as well as their mechanical impact with the Earth. Previous work suggests that subterranean
electrical discharges may not only cause earthquakes but also trigger the eruption of kimberlite. Here it is proposed that
these disruptions of the Earth’s internal electrical field are the result of external factors affecting the Earth’s electric
field, such as the close approach of a large meteoritic body. It is also suggested that crypto-ring structures may have a
similar genesis, as they appear to have a spatial association with kimberlite diatreme fields.
Keywords:
kimberlite, meteorite, electric field, diatreme, ring structure
T
he proposed model of kimberlite genesis by near-Earth intruder interaction suggested by the author is based on
four separate groups of data. Until recently, each particular group showed no logical connection with the other
three, but when considered collectively all appear related.
Group 1. Subterranean electrical discharges
Finkelstein and Powell [1] were the first to propose that subterranean electro-discharges ("subsurface thunderstorms")
are the true cause of some earthquakes. Alekseevsky and Nikolaeva [2], specialists in diamond geology, expanded on
this idea and first suggested that the cavities of kimberlite diatremes may be the breakdown channels of a "giant
condenser" between the Earth's surface and mantle. Both of these hypotheses were supported by Vorob'yev [3], who
suggested the presence of strong electric fields and discharges within the dielectric rocks of the Earth’s crust.
Diatremes (channels from the Earth's interior) are the result of subsurface electrical discharges, their explosive effects,
the mechanical fluctuations of rock destruction under conditions of strong electrical fields (>104 V/cm), and the
melting of channel walls. The melting of the rocks produces hot gases (possibly plasma), which escape from the
Earth’s upper mantle at great velocity, destroying the tops of the channel and forming explosive, funnel-like craters.
Molten magma then ascends the channel behind the plasma.
According to Vorob'yev [op cit] these electrical processes and the electrical explosions are a possible explanation of
the formation of pipes and some ring structures. This research was continued by Stepanov [4] and Balasanyan [5].
They suggested that the power of electrical discharges in the Earth's crust, with their energy concentrated in a small
area, is sufficient to form explosive structures. The conclusion drawn by Balasanyan [5] is worth noting: A necessary
condition for electrical discharges in the Earth's crust acting like a trigger is a sharp increase of negative charges
on the Earth's surface affected by atmospheric electricity.
Group 2. Meteoritic bodies (MBs) as sources of electric fields
Astapovitch and Solyanik [6, 7] considered the process of accumulation of positive charges on the surface of MBs
moving through the Earth's atmosphere. MBs induce negative charges on the Earth’s surface within zones of influence
called "tension spots", in the same manner as thunderstorm clouds. Solyanik [7] and later Nevskiy [8] made
calculations that showed electrical discharges between MBs and the Earth’s surface are possible. Both of them suggest,
for example, that the explosion of the famous Tunguska body was caused by electrical discharges. For a long time
these explanations did not gain support in scientific circles, and only recently have they started to attract attention.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
19
These data are well known by specialists in the field of electrophonic fireballs, but have still to be recognized by
geologists. Data that have been accumulated point to the influence of the energy of MBs on objects on the Earth,
including the following:
(i) People and animals exhibit signs of fear and a sense of danger (before observing MBs).
(ii) Damage to TV, electrical and radio equipment, bulbs catching fire in switched-off electric networks, formation
of St. Elmo’s lights, e.g. during the time the Chulym and Vitim fireballs passed over Siberia in February 1984 and
September 2002 respectively.
(iii) Activation of seismic processes.
The effects identified in (ii) above form the basis for supposing that the main causes of the energy influence are electric
(i.e. electromagnetic) fields. All of these effects were observed in connection with the appearance of small MBs
(approximately 1 to 40 meters in diameter) that burned or blew up in the atmosphere. Imagine the scale of the effects
that might occur if the MB entering the Earth’s atmosphere was a huge asteroid more than one kilometer in diameter.
Group 3. Structural independence of diatreme zones and fields
Analysis of the distribution patterns of diatreme zones and fields reveals a common independence relative to the crustal
structure, including the magma controlling faults described by various authors [9-13 and many others]. For example,
the well-studied Markha-Olenek kimberlite zone, with a length of about 750 km, shows no spatial-genetic connections
with major structures of the northeastern Siberian platform (pre-Vendian faults, relief of crystalline basement, main
fold structures of the cover, and basite-controlling zones) [9]. The recognition of this structural independence led to the
idea of their origin in terms of a "hot spot" by Zhitkov [14]. This hypothesis has now received serious
acknowledgement in the east of the USA by Heaman and Kjarsgaard [15]. However, as the quoted authors note, it is
not universal and is not applicable to kimberlite fields elsewhere in North America. Besides, it can’t explain the
deficiency of magmatic melt in the diatremes that is the main distinctive feature of those structures.
Group 4. Spatial-temporal connections of ring explosive structures and diatreme fields and zones
Bucher [16] was the first to pay attention to the spatial-temporal connections of some ring explosive (“cryptovolcanic”)
structures on the one hand, and diatreme fields and zones on the other. He illustrated this with some examples from the
USA and Germany. His ideas were developed later in the publications of Vaganov et al. [17], Nicolayesan and
Fergusson [18], and many others. The most convincing argument for the relative connection of these structures are the
ring explosion structures of Ries (24 km in diameter) and Steinheim (3 km) in southern Germany. These structures are
along the same straight 100-kilometer-long line as the explosive pipe field Urach. The K-Ar age of these formations
are identical, namely 14.8 Ma.
Khazanovitch-Wulff [19a] gave other examples of the spatial connection between diatreme fields and ring structures.
In particular, the above-mentioned Markha-Olenek kimberlite zone (~365 Ma) forms the "train" of the large Olenek
ring structure with a diameter 250 km (D3). The author also knows of eight examples in North America, three examples
in Europe, five examples in Asia (including three with alkaline massifs on astroblemes), three in Africa and four in
Australia – a total of 23 so far. It is thought that further detailed analysis of the geological structure of continents
should result in the discovery of more occurrences of this type.
Bucher and his followers have used some of these examples as evidence of the endogenic (non-meteoritic) origin of ring
explosive structures but as there is conclusive evidence for the meteoritic origin of some of these structures, how can these
be explained?
The following mechanism, initially proposed by [19a], links the four main groups of data into one logical chain, by the
addition of one extra factor – electricity.
20
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Consider the entry into the Earth’s atmosphere of large MBs accompanied by the accumulation of electrical charge on
their surface that induces a zone of electrical “mirror charge” or tension spot, on the Earth’s surface. This electrical
tension spot moves with the MB along its projected trajectory and may even lead it.
This tension spot is the "driving force" of the geoelectrical activity in the Earth’s crust and upper mantle.
In areas with a strong electrical field in the Earth’s crust or upper mantle, diatreme fields or earthquakes could be
triggered when the electric discharges either reach or fail to reach the Earth’s surface respectively (Figure 1). In both
cases, if the MB accumulates an extremely large electrical charge or reacts electrically with the Earth, then it can be
destroyed by the electrical stresses produced by the encounter. The Tunguska and Sikhote-Alin events are possible
examples of such explosions.
Therefore the Urach diatreme field could also be interpreted as a "diatreme train" of a large MB which was split into
two parts by electrical stresses. The smaller part formed the Steinheim crater and the larger one, the Ries crater.
Naturally, the flight trajectory of an MB in the Earth’s atmosphere is independent of geological structures in the area
and could explain the random geological position of diatreme fields and zones on the Earth’s crust.
Ring explosive structures can form in at least two ways. Firstly, as the result of the interaction between high electric
fields induced by an MB and zones of accumulations of electric charge in the Earth’s crust (for example, zones of deep
faults). Examples of these structures are Zhamanshin (Kazakhstan) and Ternovskaya (Ukraine), centered on deep faults
that cannot be regarded as impact fractures of a cosmogenic body [19b].
Secondly, as a result of the MB’s impact with the crust. In both cases, the reasons for the spatial-temporal connections
between the diatreme "trains" and ring explosive structures are clarified by this MB electrical link.
It has been noticed that not all diatreme fields have associated astroblemes and vice versa. There are several possible
explanations.
(i) In some regions with a large cover of surface glacial deposits (for example, Canada and northwestern Russia),
incomplete geological knowledge may mean that existing associated diatreme fields and astroblemes may not yet
have been identified.
(ii) In some cases, it is possible that no electric discharge occurred between the Earth’s lower crust and the Earth’s
surface. For example, if the MB had a near vertical trajectory there might have been no time for a large charge to
accumulate or there may have been no zones in the Earth’s crust inside the MB's tension area with electric fields
strong enough to cause an electrical discharge to the Earth’s surface. In this case, "underdeveloped" explosion
structures could form inside this area, for example Stopfenheim dome northeast of the Ries crater, Hatzium Dome
inside the Gibeon kimberlite and meteorites, Namibia [19c], and others.
(iii) A diatreme field without an associated astrobleme may be the result of an MB which accumulated its maximum
possible charge before impact but was destroyed in the atmosphere as a result of internal electrical stresses.
(iv) In uplifted districts astroblemes could be completely eroded while the roots of the diatremes connected with them
could remain.
Additional new information shows that not only MBs, but even aircraft, may produce seismic activity in certain
districts. In 1992, re-entry of the Space Shuttle into the Earth’s atmosphere produced seismic signals that were
recorded by the Washington RSN and described by Qamar [20].
Conclusion
Thus, the geological consequences of the interaction between large MBs with the Earth are not limited to mechanical
impact, but may also result from electrical stresses in the atmosphere and the Earth’s crust, producing seismicity, local
partial melting of the mantle and the eruption of kimberlites to the Earth’s surface.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
21
Figure 1. Main events in the Earth’s atmosphere and lithosphere associated with intruding large MBs (diameter >1 km?). Black
lenses – zones of strong, localized electric charge. Black bold vertical lines in the crust – faults with strong electric fields. Thin
vertical lines – channels of electrical discharges associated with magma (diatremes) or internal short circuits (earthquakes) from
failure to reach the Earth’s surface.
References: [1] Finkelstein, D. and Powell, J. (1971) XV Gen. Assembly Int. Union of Geodesy and Geophisics, Moscow,
part 8, 35. [2] Alekseevsky, K. and Nikolaeva, T. (1972) Journal “Znaniye-Sila”, N. 4, 30. [3] Vorob'yev, A.A. (1975)
Physical Factors Governing the Occurence and Properties of Plutonic Material: Strong Electrical Fields in the Earth’s
Interior (in Russ.), Tomsk University Press, 296p. [4] Stepanov, O. (1989) Sov. Geol., No. 12, p. 95-104. [5] Balasanyan, S.
(1990) Dynamic Geoelectric Theory (in Russ.), Nauka Press, Novosibirsk, 232p. [6] Astapovitch, I.S. (1958) Meteoric
phenomena in the Earth’s atmosphere (in Russ.), Fismatgiz, 640p. [7] Solyanik, V.: a) (1959) Yuniy Tehnik, N. 3, p. 64-65;
b) (1980) Vzaimodeystviye meteoritnogo veschestva s Zemlyoy. Novosibirsk: Nayka, 178-188. [8] Nevskiy, A. (1978)
Astronom. Vestn., No. 5, p. 206-215. [9] Brakhfogel’, F.F. (1984) Geological Aspects of Kimberlite-Igneus Activity in the
Northeast of the Siberian Craton (in Russ.), Yakutsk, 128p. [10] Milashev, V. (1984) Explosion pipes (in Russ.), Nedra
Press, 284p. [11] Vladimirov, B.M., et al. (1990) Kimberlites and Kimberlite-Like Rocks (in Russ.), Novosibirsk: Nauka,
264p. [12] Mitchell, R.H. (1986) Kimberlites: mineralogy, geochemistry, and petrology. NY, 442p. [13] Skinner, E.M., et al
(1992) Geol. and Geophis., No. 10, p. 33-40 (in Russ.). [14] Zhitkov, A.N. (1995) Extended Abstracts of 6-th International
Kimberlite Conference. Russia, p. 692-694. [15] Heaman, L.M., Kjarsgaard, B.A. // EPSL, 178 (2000), p. 253-268. [16]
Bucher, W.H. (1963) Am. J. Sci, vol. 261, No. 7, p. 567-649. [17] Vaganov, V.I., Ivankin, P.F., Kropotkin, P.N., et al.
(1985) Explosive Ring Structures of Shields and Cratons (in Russ.). Nedra Press, 200p. [18] Nicolayesen, L. and Fergusson,
J. (1990) Tectonophysics, vol. 171, No. 1/4, p. 303-335. [19] Khazanovitch-Wulff, K.K.: a) (1991) Transactions of USSR
Academy of Sci., Earth Sci. Sections, vol. 320, No. 7, p. 127-131; b) (1994) Doklady Akad. Nauk, vol. 337, No. 1, p. 83-87;
c) (2001) Abstracts of the 64-th Annual Meteor. Soc. Meeting, 78. [20] Qamar, A. (1993) Seismol. Research Lett., vol. 64,
No. 1, p. 46.
22
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
THE GREAT TWIN EARTHQUAKES IN LATE 2006 TO EARLY 2007 IN THE
KURIL ARC: THEIR FORERUNNERS AND THE SEISMICITY-TECTONICS
RELATIONSHIP
Claude BLOT
Villa Mariette, 112 Impasse des Mesanges,
83210 La Farlede, France
[email protected]
Dong R. CHOI
Raax Australia Pty Ltd
6 Mann Place, Higgins, ACT 2615, Australia
[email protected]; www.raax.com.au
Boris I. VASILIEV
V.I. Il’ichev Pacific Oceanological Institute, Far Eastern Branch, Russian Academy of Sciences,
Vladivostok, 690041, Russia
[email protected]
Abstract: The great twin earthquakes on 15 November 2006 and 13 January 2007 in the central Kuril Archipelago are linked
to deep precursors in the Sea of Okhotsk in 2002 to 2004 by the seismic energy transmigration (ET) law established by the
senior author of this paper. Analysis of geological and tectonic information shows that the deep precursors were generated at
the northern margin of a distinctive NW-SE structural high block running between Simushir and Shiashkotan Islands in the
central Kuril Arc (Simushir-Shiashkotan High Block = SSHB): the northern margin of the SSHB in the central Okhotsk Sea
meets a major perpendicular NE-SW deep-seated tectonic zone (Korea-Kamchatka Tectonic Zone). The shallow main
tremors and aftershocks occurred on this structural high adjacent to the Kuril Trench fault zone. The similar earthquaketectonics relationship seen in the recent devastating earthquakes in Indonesia, Kashmir and Japan and the ET law open the
door to scientific earthquake prediction in conjunction with short-term prediction methods – such as the earthquake vapor
cloud concept, the seismo-electro-magnetic effect, and other various precursory signals including animal behavior.
Keywords: Great Kuril earthquakes of November 2006 and January 2007, deep forerunners, energy transmigration,
Simushir-Shiashkotan high block, structural control of earthquakes, earthquake prediction
1. Introduction
T
he 15 November 2006 and the 13 January 2007 earthquakes in the central Kuril Islands (Figs. 1-4) are the largest
earthquakes which occurred in the region since the early 20th century. The Central Kuril Islands earthquake in
1915 is estimated to have had a magnitude of about 8. Two other great earthquakes have been recorded in the KurilKamchatka region; one in the southern Kuril Island chain in 1963 (magnitude 8.5), and another offshore Kamchatka in
1952 (magnitude 9).
The occurrence of these remarkable earthquakes is considered the consequence of extraordinary convergence of
upward energy transmigration from numerous strong shocks at depth under the Okhotsk Sea. The senior author of this
paper linked the latest twin quakes to the earlier deep forerunners which occurred in 2002 to 2004 in the Okhotsk Sea
based on his ET formula (Fig. 4; Table 1). The results were passed on to the second author (DRC) for comparison with
geological and structural information. During the course of geological analysis the last author (BIV) joined the team by
providing geological data and discussion.
A comprehensive analysis based on detailed geological information available in the study region shows a strong
relationship between earthquakes (in their occurrences/migration) and geological structures, as has been well establish
in other world regions including Japan, Kashmir and Indonesia (Blot et al., 2003; Blot and Choi, 2004, 2005 and 2006).
We will introduce here some of the regularities and new findings which will shed additional light on the study of
earthquake-tectonic relationship and scientific earthquake prediction.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
23
2. Great twin earthquakes in 2006 to 2007
A doublet of large earthquakes less than 100 km apart occurred in the Central Kuril Archipelago within two months of
one another (Figs. 1 & 2; Table 1; EMSC and NEIC websites, and other organizations):
2006 November 15: 46.62oN 153.22oE; depth, 7-28.5 km; magnitude, Mw: 7.9-8.3
2007 January 13:
46.27oN 154.46oE; depth, 10-15 km; magnitude, Mw: 7.0-8.2
Figure 1. Bathymetry of the study region. Note no islands or poor development of islands between Simushir and Onekotan
Islands and conspicuous positive topography in the northern part of Zenkevich Rise. The trench also shows swell in the region. A
distinctive NW-SE structural high is present in the area. Two seismic events discussed in this paper are indicated. No. 8 = 15
November, 2006; no. 11 = 13 January, 2007.
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
These events took place in an uninhabited region, which is why there were no casualties, and the generated tsunamis
were weak on the Pacific coasts. They occurred to the east of Simushir Island near the trench, on both sides of the
Kuril-Kamchatka Trench with aftershocks distributed in two distinctive linear trends (Figs. 2 & 3).
The ET law (Blot, 1976; Grover, 1992) located the deeper precursors of these two shallow great quakes in two areas
under the Sea of Okhotsk region (Fig. 4): the western group (nos. I, 1 and 1’) – 146-147oE and around 48oN; and the
eastern group (nos. II, a, 2 & 4) – 148.5oE to 151oE and 51.5oN to 51.3oN. Moment tensor solutions of most of the
precursors (particularly direction of tension – cascade effect) are roughly harmonious with the energy transmigration
direction (Fig. 4).
Shou has noticed the possible precursory earthquake clouds from these two events prior to their occurrence, although
he did not raise the findings to a formal prediction status due to problems with satellite image quality (page 30 of
http://quake.exit.com, pers. comm. on 17 May, 2007): The possible clouds were noticed on 11 Nov., 2006 at 900 hrs,
four days before the first main shock on 15 Nov., 2006; and the second possible clouds on 12 Dec., 2006, at 1200 hrs,
32 days before the second mainshock on 13 January, 2007.
Figure 2. Top, EMSC map of the great Kuril earthquake (www.emsc-csem.org). Bottom, NEIC’s earthquake distribution for the
15 November, 2006 event. The locus of the 13 January, 2007 event and deep-seated tectonic zones (Choi, 2005) were added by the
present authors. The main events took place on both sides of the Kuril Trench under which a major fault zone runs (Figs. 5-7).
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
25
Figure 3. Two great earthquakes (left and center); their main and aftershocks (generated from the NEIC website) in comparison
with DEOS gravity anomaly map (right). Clear linear trends (NE-SW and minor NW-SE) in both groups are recognized.
Comparison with geological map (Fig. 5) indicates that the trend coincides with basement highs (Paleozoic-Mesozoic). Almost all
of the aftershocks as well as the mainshocks are situated on the Simushir-Shiashkotan High (Fig. 6).
Figure 4. Map showing the links between the deep and shallow quakes. This was created solely based on the ET formula by the
senior author (CB) without geological and structural considerations. These links perfectly match the overall tectonic picture of the
region, see Fig. 6. Moment tensor solutions are also generally harmonious with the transmigration direction. See Table 1 for more
details of each quake.
3. Geological and tectonic analysis and comparison with seismic events
The study region where the quakes concerned occurred has been most intensely studied by many Russian scientists
mainly in the Soviet Union era; to cite a few, Sergeev et al. (1983), Shilo & Tuezov (1985), Vasiliev (1986), etc. All
results were synthesized in the “World Geological Map” (Fig. 5; Jatskevich [ed.], 2000) and in the “International
Geological-Geophysical Atlas of the Pacific Ocean” (Udintsev [ed.], 2003). It is a rare region in the world to have such
highly detailed submarine geological maps, allowing us to analyze accurately the relationship between earthquakes and
geological structure.
26
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
1) Simushir-Shiashkotan High Block and general geological structures
The geological map (Fig. 5) clearly illustrates that the study region is dominated by two groups of structural trends: 1)
NE-SW trend which is parallel to the Kuril Arc, and 2) NW-NE trend which dissects the island arc and the trench into
numerous blocks. The Kuril Trench is underlain by a major fault zone (see Figs. 5 & 7) and both sides of the Trench
are occupied by basement blocks (Precambrian-Paleozoic-Mesozoic).
One of the most outstanding structural features among them is a NW-SE structural high block which we newly coin as
Simushir-Shiashkotan High Block (SSHB; Fig. 6). It is expressed clearly on the sea floor topography (Fig. 1):
topographic high under the deep Pacific forming the northern ridge of the Zenkevich Rise. The Kuril-Kamchatka
Trench is separated into two parts by this high – note the shallower trench depth where this high block crosses. The
island arc-side slope of the trench on this high also shows irregular topography particularly in the area shallower than
3000 m – probably due to tectonic instability and erosion of the High. The SSHB is covered by younger sediments
under the Okhotsk Sea making it difficult to trace in submarine topography (Fig. 1). However, it is unequivocally
traced on geological (Fig. 5) and gravity (Fig. 6) maps: the geological map shows that older rocks (Upper Paleozoic –
Mesozoic) are cropped out on the sea floor with an overall NW-SE extension.
In addition to the above, some important geological information must be emphasized here, particularly regarding the
composition of the “oceanic crust” and the pervasive presence of ancient continental rocks in the region. Vasiliev
(1986) dredged extensively in the deep Pacific Ocean floor to the south of Simushir Island (Fig. 7). He found a major
fault zone running under the trench, which is confirmed in a seismic profile taken across the trench (Choi and Vasiliev,
in preparation). This major deep fault zone coincides with O’Driscoll’s (1980) Lauratian-2 Trend, which one of the
authors recently referred to in relation to SE Asia and Indian Ocean tectonics (Choi, 2007). The dredgings
unequivocally proved that the “oceanic crust” in the northwestern Pacific consists of the continental rocks – crystalline
garnet schist, pyroxenite, gabbro, and other metamorphic rocks (see also Vasiliev and Yano, 2007, in this NCGT issue,
p. 3-17), mostly Precambrian in age.
Although all seismological institutions and their websites blamed the twin quakes on Pacific plate subduction (NEIC
and EMSC, for example), geology and structural data briefly mentioned above flatly negate the application of plate
tectonics to the study region.
2) Relationship between earthquakes and geological structure
(1) Main and aftershocks
When the main and aftershocks of both twin quakes are plotted on geological/structural maps and profiles (Figs. 3, 57), it becomes clear that both quakes occurred on a series of NE-SW basement high blocks within the SSHB. The two
NE-SW aftershock swarms (Fig. 3) exactly coincide with the basement high structures on both sides of the Trench
(Figs. 5 & 7): outer arc high in the continental slope (Nov. 2006 main and aftershocks) and a structural high east of the
trench (Nov. 2006 aftershocks and Jan. 2007 main and aftershocks). It is worthy of note that the first shocks hit both
highs, whereas the second shocks were confined to the oceanic-side structural high (Fig. 3). The less distinctive,
narrow, perpendicular NW-SE linear trend (Figs. 3) coincides with fault zones (Fig. 5). These facts imply that the
reactivation of the outer arc high and a fault zone beneath the Kuril-Kamchatka Trench within the SSHB segment was
the key movement of the Kuril twin earthquakes, which is obviously coming from the active continuous subsidence of
the Trench and the northwestern Pacific.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
27
Figure 5. Geological map of the study region (Jatskevich [ed.], 2000) with relevant earthquakes superimposed. These earthquakes
are discussed in the text and listed in Table 1. There are two groups in shallow quakes: one on the continental side and another on
the oceanic side of the trench. Two groups of precursory earthquake groups are also recognized in the Okhotsk Sea. Note the
presence of Paleozoic-Mesozoic basement at and near the Kuril Trench, and a NW-SE structural high between Simushir and
Shiashkotan Islands. All earthquakes occurred in relation to this structural high block.
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 6. Gravity anomaly map generated from the DEOS website, right; and tectonic map (from Jatskevich [ed.], 2000) with
earthquake foci, left. Numbered quakes are listed in Table 1. All numbered quakes are related to a major NW-SE structural high =
Simushir-Shiashkotoan High Block (SSHB). A major fault line with numerous offsets along the trench is from Neotectonic map in
Jatskevich [ed.] (2000), indicating thrusts or reverse faults. Seismic profiles taken across the trench (Udintsev [ed.], 2003) reveal a
broad, major fault zone underlying in deeper section under the trench (Choi and Vasiliev, in prep.).
Figure 7. Geological profiles and the sites of dredged continental rocks in the NW Pacific. The great twin earthquakes are
projected on the crustal profile (top right). A seismic profile across the trench (Udintsev [ed.], 2003; Choi and Vasiliev, in prep.)
indicates a major fault zone under the trench.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
29
(2) Deep precursors
Deep shocks which were linked to the great twin earthquakes (Fig. 4) are positioned near the northern end of the SSHB
(Figs. 5 & 6): the eastern group is situated north of the highest area of the basement where NE-SW deep tectonic zone
(Korea-Kamchatka Tectonic Zone; Choi, 2005) crosses. The eastern group occurred from late 2002 to early 2004. The
western group is located along fault zones developed at the northwestern margin of the SSHB. All of the three deep
shocks were registered in 2002 (March and November). One intermediate depth shock (no. 3; Figs. 4 & 5) behind the
Simushir Island was linked to a deeper precursory shock no. a, and later migrated to shallow main event no. 8 (Fig. 5).
This (no. 3) is an important shock in considering the route of energy transmigration from deep to shallow depths – all
occurred on or at the boundary of the SSHB.
(3) Temporal and spatial distribution
All seismic events with magnitude 4 or larger in the Okhotsk Sea and the Kuril Arc from 2000 to 2007 (until April) are
plotted in Fig. 8 regardless of their depths. Quite conspicuous is the almost total absence of deep seismic activity
between 2005 and 2007 north of Simushir Island (Okhotsk Sea) where the SSHB underlies. In contrast, numerous deep
quakes have been registered from 2002 to 2004 in the same area. The delay of several years between the deep and
shallow quakes validates the ET concept.
4. Discussion
The present study demonstrates yet another important relationship between seismicity and tectonics, which the current
authors have been pursuing for recent catastrophic earthquakes (Blot et al., 2002; Blot and Choi, 2004, 2005, 2006a &
2006b). Although further studies are needed, it seems we now have strong cases for various aspects of the seismicity
and tectonics relationship:
- Loci of deep precursory quakes.
- Path of energy transmigration.
- Loci of main and aftershocks.
1) Loci where deep forerunner earthquakes are generated
Choi (2005) already argued that deep seismicity (over 350 km) is related to deep-seated tectonic zones based on
analysis of all deep seismic and deep tectonic zones in the Pacific margins and SE Asia (Fig. 9). This general rule is
applicable to most deep precursory quakes in Japan, Kashmir, and Indonesia (Sumatra and Java) as have been
examined by the present authors (Blot and Choi).
2) Energy transmigration path
Naturally earthquake energies exploit weak, permeable zones in the mantle and the crust for upward transmigration;
large-scale thrust/reverse fault systems developed at the ocean-continent boundary (Wadati-Benioff zone; Fig. 9). In
the shallow section within the crust, although they primarily follow the seismo-focal thrust zone, the movement seems
to be complex, probably controlled by the local network of fracture systems and block structures.
3) Main and aftershocks
So far as examined, most of the main and aftershocks were found to occur on or at the boundary of structural high
blocks. These seismically active structural highs are usually situated in the actively subsiding tectonic regime. This
explains the concentration of shallow quakes at the outer arc in the continental slope. The main shocks also tend to
occur along fault zones within the structural high and aftershocks tend to be distributed widely throughout the
structural highs. This fact indicates that the basement ridges are networks transmitting compressional force as basement
ridge tectonics claims (Anfiloff, 1992) and that its stress release was triggered by energies migrating from the deep
Earth.
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 8. Earthquake distribution from 2002 to 2007 (April) generated from the NEIC website. Only quakes with magnitude 4 or
larger are plotted. Note that deep quakes are seen in the Sea of Okhotsk from 2002 to 2005 in the area where the SSHB underlies.
The burst of shallow quakes occurred at the continental margin off Simushir and Shiashkotan Islands in 2006 to 2007 when there
are almost no deep quakes (300 km or deeper) in the Okhotsk Sea.
5. Application to earthquake prediction
Blot’s ET concept and the established relationship between seismicity and tectonics by the present authors present
indisputable evidence that the earthquakes are primarily caused by energies rising from the deeper Earth which interact
with shallow geological/geophysical conditions. Scalera (2004), based on the analysis of seismic tomography,
proposed upward-moving (upducting) mantle material to explain the Wadati-Benioff zone in the Mediterranean area.
Only this way of thinking makes it possible to reasonably understand Shou’s (2006) earthquake vapour cloud concept
which allows major earthquakes to be predicted with almost 100% accuracy wherever high-resolution satellite images
are available. Other short-term prediction methods including the seismo-electro-magnetic effect and other preearthquake phenomena as discussed by Bapat in this NCGT issue (p. 34-38) are all explainable only by upwardmoving mantle energies. The plate tectonic explanation based on downgoing slab subduction as a cause of earthquakes
has lost its viability in earthquake prediction.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
31
Figure 9. Generalized upper mantle profile showing the Wadati-Benioff zone (slightly modified from Choi, 2005). The WadatiBenioff zone is primarily a thrust or reverse fault, developed on the subsiding side of a major deep tectonic zone, which now forms
the margins of deep oceans in most cases. The fault zone has become a conduit for deep energy to migrate to the Earth’s surface.
Deep Earth materials, while traveling upward along the weak, permeable zone formed by the fault zone, discharge their energies at
different depths: first mainly heat, then liquid/gas? (producing volcanic/plutonic magmas), and near the surface vapour/gas?
(triggering earthquakes). Compare this profile with that of Scalera in this NCGT issue on page 65.
The ET concept is a medium-term prediction method. Based on deep precursory signals and geological/structural
conditions, it can predict possible location, magnitude, and time (Grover, 1998; Blot et al., 2003). But its time frame is
several months to half a year, due to the slowing down of transmigration speed at shallow depth, and the difficulty of
predicting at what depth and exactly where the main event will occur. Therefore, to give more accurate short-term
predictions, it must be combined with other suitable methods. A holistic approach by a multidisciplinary team is
needed for scientific earthquake prediction by fully utilizing high-resolution satellite information as well as all other
available resources; clouds, temperature, geomagnetics, gravity, electric geo-potential, and animal behavior, supported
by detailed geological and geophysical information (Shou, 2006; Bapat, 2007; Freund, 2006; and others).
6. Concluding remarks
This study from the Kuril Arc reinforces our earlier assertions on many aspects of the seismicity-tectonics relationship.
So far as examined, earthquakes are related to four factors: 1) major fault zones, 2) structural highs, 3) actively rising
or subsiding tectonic regimes, and 4) upward-moving deep-Earth energies. We have seen all of these factors intimately
working together in producing great earthquakes. Of particular importance among them is the close association of
energy discharge/seismicity, mantle high and active subsidence. This explains the close association between mantle
highs and topographic depressions: notably SE Asia (Borneo-Vanuatu Geanticline by Choi, 2007), Mediterranean Sea,
and the Caribbean Sea. The highest intensity of shallow quakes under the outer arcs in the continental margins of the
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Pacific and the Indian Oceans is due to a combination of active subsidence of the margins and structural high (outer
arc).
The ET concept has been again validated by geological data from the Kuril Arc. This in turn proves that the
earthquakes are caused by rising mantle mass which interacts with varying local geological/geophysical conditions at
shallow depth, instead of widely-believed oceanic plate subduction.
On the basis of a series of studies on the recent earthquakes and tectonics, we can confidently declare that catastrophic
earthquakes are predictable. To make this reality, the ET concept and geological/geophysical data must be combined
with short-term earthquake prediction methods including the earthquake vapour cloud concept and the seismo-electromagnetic effect along with all other precursory signals.
References cited
Anfiloff, V., 1992. The tectonic framework of Australia. In, Chatterjee, S & Hotton, N., III. (eds.), “New Concepts in Global
Tectonics”, p. 75-109. Texas Tech Univ. Press, Lubbock.
Bapat, A., 2007. Seismo-electro-magnetic and other precursory observations from recent earthquakes. NCGT Newsletter, no. 43,
p. 34-38.
Blot, C., 1976. Volcanisme et sismicité dans les arcs insulaires. Prévision de ces phénomènes. Géophysique, v. 13, ORSTOM,
Paris, 206p.
Blot, C., Choi, D.R. and Grover, J.C., 2003. Energy transmigration from deep to shallow earthquakes: a phenomenon applied to
Japan – toward scientific earthquake prediction. NCGT Newsletter, no. 29, p. 3-16.
Blot, C. and Choi, D.R., 2004. Recent devastating earthquakes in Japan and Indonesia viewed from the seismic energy
transmigration concept. NCGT Newsletter, no. 33, p. 12.
Blot, C. and Choi, D.R., 2005. Forerunners of the catastrophic Kashmir Earthquake (8 October, 2005) and their geological
significance. NCGT Newsletter, no. 37, p. 4-16.
Blot, C. and Choi, D.R., 2006a. On the recent catastrophic Java earthquake (May 26, 2006) and Merapi volcano eruption: their
forerunners. NCGT Newsletter, no. 39, p. 31-36.
Blot, C. and Choi, D.R., 2006b. The Great Southern Java Earthquake on July 17, 2006 and its tectonic perspective. NCGT
Newsletter, no. 40, p. 19-26.
Choi, D.R., 2005. Deep earthquakes and deep-seated tectonic zones: a new interpretation of the Wadati-Benioff Zone. Boll.
Soc. It., spec. vol. no. 5, p. 79-118. (www.uniurb.it/ISDA/guestdata/Volume_speciale_5.zip)
Choi, D.R., 2007. Borneo-Vanuatu Geanticline and the tectonic framework of Southeast Asia and the Indian Ocean. NCGT
Newsletter, no. 42, p. 18-25.
Choi, D.R., Vasiliev, B.I. and Tuezov, I.K., 1990. The Great Oyashio Paleoland: a Paleozoic-Mesozoic landmass in the
northwestern Pacific. In, “Critical aspects of the plate tectonics theory”, v. 1 (Criticism on the plate tectonics theory).
Theophrastus Publications, S.A., Athens, p. 197-213.
Freund, F., 2006. When the earth speaks: understanding pre-earthquake signals. First European Conf. earthquake Engineering,
Geneva. 3-8 Sept. 2006, p. 1-10.
Grover, J.C., 1998. Volcanic eruptions and great earthquakes. Advanced warning techniques to master the deadly science.
Copyright Publishing Co., Ltd., Brisbane, 272p.
Jatskevich, B.A. [ed.], 2000. Geological Map of the World. 1:15,000,000. Ministry of Natural Resources of Russian Federation,
Russian Academy of Sciences.
O’Driscoll, E.S.T., 1980. The double helix in global tectonics. Tectonophysics, v. 63, p. 397-417.
Scalera, G., 2004. A new interpretation of the origin of the Wadati-Benioff zones in the Mediterranean region. NCGT Newsletter,
no. 32, p. 15-24.
Sergeev, K.F., Krasny, M.L., Neverov, Yu.L., and Ostapenko, V.F., 1983. Substance of crystalline basement of the Zenkevich
Rampart southeast flanks. Tikhookenaskaya Geologiya (Pacific Geology), no. 2, p. 3-8.
Udintsev, G.B. [ed.], 2003. International Geological-Geophysical Atlas of the Pacific Ocean. Scale, 1:10,000,000. Size, 70 x
100 cm. Moscow-St. Petersburg, Russia. 172p. International Oceanographic Commission (in English and Russian)
Vasiliev, B.I., 1986. The result of dredging of some submarine mountains in Japan marginal oceanic rampart. Tikhookeanskaya
Geologiya (Pacific Geology), no. 5, p. 35-42.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
SEISMO-ELECTRO-MAGNETIC AND OTHER PRECURSORY OBSERVATIONS
FROM RECENT EARTHQUAKES
Arun BAPAT
Consulting Seismologist
1/11, Tara Residency, 20/2, Kothrud, Pune – 411038, India
E-mail: [email protected]
Abstract: Seismic events since 2001 have taken a heavy death toll of about 300,000 people. In order to save lives it is
necessary to issue some sort of advance warning. Field surveys of the Bhuj (2001), Andaman (2004) and Kashmir (2005)
earthquakes have yielded useful clues about earthquake prediction. Changes in the geomagnetic field at the epicentral region
affect radiowave propagation. This is called the Seismo-Electro-Magnetic Effect, and has been found to be highly reliable
and useful. This effect and other seismic precursors are discussed in the paper.
Keywords: earthquake prediction, seismo-electro-magnetic effect, geomagnetic field
Introduction
I
ndia and neighboring countries have suffered heavily due to earthquakes and resulting tsunamis. According to
official estimates, about 300,000 people have died. Paradoxically, amongst all natural disasters, an earthquake does
not kill anybody. It is the collapse of man-made structures that causes death. Keeping in view this grand philosophical
dictum, it could be said that constructing aseismic buildings will reduce the death toll. The next most significant action
during the pre-seismic period is to issue a suitable warning (maybe a few minutes or hours in advance) to alert the
population at large. This will definitely reduce the death toll during earthquakes. A large number of engineers,
scientists, researchers and administrators firmly believe that “earthquakes cannot be predicted”. The author used to
hold a similar view. After having undertaken field surveys of the Bhuj Earthquake of 26 January 2001, the Andaman
Sumatran Earthquake of 26 December 2004 and the Kashmir Earthquake of 8 October 2005, the author has changed his
opinion and he is more or less convinced that it is possible for earthquake prediction to become a reality in the next few
years.
Seismologists, geologists and earthquake engineers have been viewing earthquakes and associated strain release as
mechanical processes. Most earthquake-prediction-related research deals with historical and current seismic data and
performs various statistical probabilistic analyses and studies. These studies are supplemented by some field
observations, such as field strain data and geodetic data about level changes etc. The prevailing view is that it is not
possible to predict earthquakes by seismic, geodetic or geological methods. But earthquake prediction is possible by
non-seismic and non-geodetic methods. Any natural processes, including earthquakes, give a number of precursory
signals. Some of them are non-seismic and non-geodetic. Interestingly, these signals have a wide spectrum. They could
be detected by animals and sensitive human beings and also by satellites and technologically advanced ground
measurements. However, a number of researchers have expressed doubts about the very idea of earthquake prediction
(Bernard et al., 1997; Hough, 2002; Keilis-Borok, 2002; Uyeda, 1998). Some researchers (Campbell, 1998; Geller et
al., 1997) have opined, “earthquakes cannot be predicted”. The effect of electric geo-potential and geomagnetic fields
and associated parameters have been discussed at the European Conference on Earthquake Engineering and
Seismology at Geneva (Freund, 2006).
Some Significant Precursory Indicators: Changes in the geomagnetic field, gravity field, electric potential, rise in
well-water, appearance of springs etc. are quite well known (Plastino et al 2002, Sano, et al 1998). The Jan. 16, 1995
Kobe earthquake was preceded by earthquake lights (Tsukuda 1997). Similar observations were reported from Mexico
and other seismic regions of the world (King, 1983; Lomnitz, 1994). There are also reports of rises in sub-surface,
surface and atmospheric temperatures. Usually the rise in temperature starts about 150 to 200 days before the
earthquake occurs. The rise takes the form of a ramp-shaped plot. About three to five days before the earthquake it
suddenly shoots up and peaks on the day of the earthquake. The observed rise on the day of the earthquake could be
anything in the range of 6.0 to 10.0o C. On the day of the Kashmir Earthquake of October 8, 2005, the atmospheric
temperature was 10° C higher than the average temperature. Increased infrared radiation recorded by satellites has been
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
35
a good earthquake precursor (Qiang, et al 1990). Low-frequency emissions and extremely low radiation have also been
discussed and have provided useful information about precursory behavior (Gershenzon and Bambakidis, 2001;
Yoshida, et al. 1994; Yen et al., 2004). There is large number of reports about abnormal animal behavior (Rikitake,
1984). It has also been observed that some sensitive human beings are useful as earthquake precursors (Bapat, 2005).
This is observed in hospitals. It was found that the number of deliveries and outpatients increases to five to seven times
the daily averages (Bapat, 2005).
Seismo-Electro-Magnetic Effect: When the temperature of any magnetic body increases, the magnet starts losing its
magnetic properties. The magnetism decreases as the temperature rises. The temperature at which the magnet entirely
loses its magnetism is known as the Curie temperature or Curie point. In the case of the thrust type of earthquake
mechanism, two sides or parts move over one another. The frictional movement during the initial stages is very small.
A few days (about 150 to 200 days) before the occurrence of a destructive earthquake the temperature starts rising.
This effect is extensively manifested at sub-surface temperature level. About 3 to 5 days before the occurrence of an
earthquake the rise is sharp and rapid and it peaks on the day of earthquake. As a result of the rise in sub-surface
temperature in the hypo-central region, the geomagnetic field declines. The reduction in the magnetic field adversely
affects the transmission and propagation of electric and electromagnetic signals. Bapat (2003) has named this the
Seismo-Electro-Magnetic Effect. It affects radios, telephones and televisions. If a radio station is transmitting a signal
at a particular frequency, say 1000 kHz, then the same will be received about ten to twenty hours before the occurrence
of the earthquake at 1100, 1200, 1300 …. 1700, 1800, 1900, 2000 kHz or more. In the case of televisions, there are
repeated audio, visual and spectral disturbances. The number of disturbances goes on increasing till the occurrence of
the earthquake. It has been seen that these effects are manifested about two to three days in advance and are observed
intensely about ten to twenty hours before the earthquake.
Theory: Why does reception frequency increase? In the case of radio transmission and reception the two main
objects are (a) a transmitter and (b) a receiver. A transmitter sends waves in all directions. A receiver receives the
transmitted signal through an antenna and the equation for reception of the transmitted signal is given by:
f = 1/ 2π√(LC)
Where
……………………………..(1)
f is frequency received by the receiver
L is inductance
C is capacitor (it may vary for different types of receivers)
2 and π are constants
It would thus be seen that the transmitted frequency does not change. The above equation is valid for coil-magnet type
receivers and also for ferrite type receivers. It is only at the reception end that the frequency is apparently enhanced.
The term L is in the denominator (note the square root sign). Even a slight change in the value of L (primarily the
geomagnetic field) would change the received frequency. Equation (1) explains the phenomenon of the SeismoElectro-Magnetic Effect. If this explanation is understood then the movement of two sections of rock along a
geological or tectonic fault and the rise in sub-surface temperature is clearly explained. Enhanced frequency reception
was seen for the first time prior to the Tashkent Earthquake of 1966. Subsequently it has been observed at several
locations. There have been reports about a rise in reception frequencies prior to earthquakes in India, Turkey, Iran,
Japan, USA, Russia, Indonesia, and Pakistan etc. In some countries the broadcasting frequencies are monitored. The
reception of the transmitted frequencies is monitored at these stations. If the reception of frequencies is within the
tolerance limits, then it is assumed that there is little change in the geomagnetic field. It is also known that cloud
lightning and hailstorms may also change the reception of frequencies. But this is transient and of short duration.
In the case of telephones, the effect is seen a few months before the occurrence of an earthquake. After the Latur
earthquake of 29 September 1993, several researchers complained about the non-availability of scientific data. Data
about changes in the magnetic field were required. As an attempt to hind cast the likely changes in the geomagnetic
field at Latur an exercise was undertaken. We collected telephone data for the period January to September 1993. Data
about the number of telephone lines installed and the number of complaints received per month were collected. During
this period, the number of installed telephones was more or less constant. The data are as follows:
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
The Latur earthquake occurred on 29 September 1993. On average there were about 3000 complaints per month for the
period January to April. In May, the number of complaints started rising. The number of telephones was more or less
unchanged. The complaints for the subsequent months were as shown in Table 1 below.
-----------------------------------------------------------Month in 1993
Number of complaints
------------------------------------------------------------May
3200
-----------------------------------------------------------June
3400
-----------------------------------------------------------July
3700
-----------------------------------------------------------August
4000
-----------------------------------------------------------September
4600
-----------------------------------------------------------Table 1: Number of telephone connections installed and number of complaints for the period May to September 1993 from the
Latur Telephone exchange. After the earthquake some additional emergency telephone lines and some temporary
exchanges were established.
The data in Table 1 indicate that the geomagnetic field started undergoing change sometime in May 1993 and it went
on changing. After examining the data in Table 1, it is observed that the rise in the number of complaints during a span
of about five months is about 53 % of the original value (from 3000 to 4600). The process of stress accumulation
accelerated during May to September and the earthquake occurred on 29 September 1993. During the post-seismic
period, some temporary new telephone exchanges were installed and there was a considerable rise in the used
telephone lines. With this background the data during post-seismic period was not used.
During the field surveys after the Latur, Bhuj, Andaman and Kashmir earthquakes, it was found that a large number of
persons had observed repeated disturbances on televisions. These included audio, visual and spectral type
disturbances.
An interesting observation was found for the first time after the 26 January 2001 Bhuj earthquake. This 7.8 magnitude
earthquake occurred at 0846 (Local Time). During the period 0600 hours to 0630 hours, most of the mobile telephones
were non-functioning or malfunctioning. It was also checked and confirmed that there were no electrical, electronic or
mechanical failures in telephone exchanges. People in Pakistan confirmed similar observations for the 8 October 2005
Muzaffarabad earthquake in Pakistan.
Some Other Reliable Seismic Precursors: Having considered the most useful, reliable, scientifically acceptable,
theoretically explained and properly understood Seismo-Electro-Magnetic Effect, it is also necessary to examine some
other precursors which were extensively observed in the case of several major earthquakes.
(a) Animal Precursor: This type of precursor is quite well known and a lot of literature exists on the subject. The
existing animal precursors are not being discussed here. But some new findings on this will be useful. It is known
that about ten to twenty hours before the occurrence of any medium to large (M>6.5) earthquake all zoological
species become disturbed, make noises and are in a hostile mood. One of the oldest recorded references is from
the Lahore zoo. About ten hours before the occurrence of the magnitude 8.25 Kangra earthquake of 4 April 1905,
all the animals in Lahore Zoo, located at a distance of about 190 km from the epicentral region were uneasy and
making shrilling noise. The latest reports from Andaman Island are useful not only for earthquakes but also for
tsunamis. In the Andaman & Nicobar Island region there is one Island known as Hut Bay. On 25 December 2004,
a number of people wanted to have a party on a 100 m long jetty. People gathered on the jetty in the afternoon and
were busy preparing the celebrations. At about 1500 hrs a snake appeared on the jetty. After another 30 minutes
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
37
five to six snakes appeared on the jetty. By about evening the entire jetty was full of snakes, toads, crabs, some
types of fishes and other marine animals. The party organizers abandoned their equipment and ran away from the
jetty. Another interesting observation was found. Normally ants travel in a straight line. A few days before the
earthquake, ants were found in a circular cluster jumping over one another. Within twelve hours of the animals
crowding the jetty, the earthquake and tsunami occurred. Hut Bay Island is located at a distance of about seven
hundred kilometers from the Sumatran earthquake of 26 December 2004. This is new finding for tsunamis.
(b) Human Precursor: There have been reports that some sensitive human beings are able to feel the incoming
earthquake. Doctors observe such precursors in hospitals. It has been found from Latur and Andaman that the
number of deliveries and OPD patients starts rising about two days in advance and it peaks on the earthquake day.
The data collected indicate that the rise is about five to seven times the average rate. Table 2 below will give some
idea about it.
------------------------------------------------------------------------------------------------------------------Number of deliveries
Latur
Andaman
_____________________________________________________________________________
Average deliveries per day
3 to 4
1 to 2
------------------------------------------------------------------------------------------------------------------Three days before earthquake
7
5
------------------------------------------------------------------------------------------------------------------Two days before the earthquake
12
9
------------------------------------------------------------------------------------------------------------------One day before the earthquake
16
10
------------------------------------------------------------------------------------------------------------------On the day of the earthquake
21
10
_____________________________________________________________________________
Table 2: Number of deliveries at Latur and Andaman prior to earthquake. After the earthquake the records reverted to the original
values.
It is seen that there is a rise of about five to seven times the average. Data about OPD patients was also collected and
showed a similar rise.
Conclusions
After surveying four major earthquakes it is found that it is possible to predict the occurrence of earthquakes (M> 6.5).
Mother Nature gives a large number of precursory indicators. One of the most important is the Seismo-ElectroMagnetic Effect, which ordinary people can observe on radios, televisions and telephones in their homes. Telephone
exchanges could serve as a magnetic laboratory with their existing equipment; no new instruments are required for this
purpose. Landline and mobile telephone companies can effectively contribute to the subject of earthquake precursors.
The human and animal precursors are equally important. In an effort to save people’s lives we have to issue some sort
of advance warning. The warning should be as narrow as possible on the time axis. During a span of five years we have
lost about 300,000 people due to earthquakes. The age-old ad-hoc assumption that earthquakes cannot be predicted
needs to be set aside. If the present advanced technological instrumentation is not capable of issuing any reliable
earthquake warning then we have to open-mindedly accept the above precursors. If the barking of dogs or cawing of
crows or the number of deliveries in a hospital can give us some reliable precursory input we should accept it without
any prejudice. The Seismo-Electro-Magnetic-Effect has a number of promising avenues which could be explored for
proper prediction-oriented technology.
38
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
References
Bapat, A., 2003. Role of Telecom in Seismic Surveillance. Proc. Nat. Sym. On Developments in Geophys. Banaras Hindu
Univ., Varanasi, p. 129 – 132.
Bapat, A., 2005. Learning from Seismic Precursors. The Dawn (Pakistan), 22 Oct. 2005.
Bernard, P. et al., 1997. From precursors to prediction: a few recent cases from Greece. Geophys. J. Internatl., p. 131, p. 467 – 477.
Campbell, N.H., 1998. A misuse of public funds: UN support for geomagnetic forecasting of earthquake of March 28, 1964.
J. Geophys. Res., v. 70, p. 2251-2253.
Freund F., 2006. When the earth speaks: Understanding pre-earthquake signals, First European Conf. Earthq. Engg. Geneva,
Switzerland, 3 – 8 Sept 2006 paper no. 6, p. 1 –10
Geller, R.J., Jackson, D.D., Kagan, Y.Y. and Mulargia, F., 1997. Earthquake cannot be predicted. Science, v. 275,
p. 1616 – 1617.
Gershenzon, N. and Bambakidis, G., 2001. Modelling of seismoelectromagnetic phenomenon. Russ. J. Earth. Sci., v. 3,
p. 247 – 275.
Keilis-Borok, V., 2002. Earthquake prediction; State of the art and emerging possibilities, Annual Rev. of Earth and Planetary Sci.,
v. 30, p. 1-33.
King, C.Y., 1983. Electromagnetic emission before earthquake. Nature, v. 301, p. 377.
Lomnitz. C., 1994. Fundamentals of earthquake prediction, 326p. New York, N.Y.
Plastino, W., Bella, F., Catalano, P.G. and Giovambattista, R.D., 2002. Radon groundwater anomalies related to the
Umbria-Marche Sept. 19, 1997 earthquake. Geophysics International, v. 41, p. 369-375.
Qiang, Z.J., Xu, X.D. and Dian, C.D., 1990. Abnormal infrared thermal of satellite forewarning of earthquake. Chinese Sci. Bull.,
v. 35, p. 1324-1327.
Rikitake, T., 1984. Earthquake forecasting and warning. D. Riedel Pub. Co., Dordrecht, Boston and London.
Tsukuda, T., 1992. Sizes and some features of luminous sources associated with the 1995 Hyogo-Ken Nanbu earthquake.
J. Phy. Earth, v. 45, p. 73-82.
Uyeda, S., 1998. VAN method of short-term earthquake prediction shows promise. EOS Trans, v. 79, p. 573-578.
Yen, H.Y. et al., 2004. Geomagnetic fluctuations during the 1999 Chi-Chi earthquake in Taiwan. Earth Planet Space, v. 56,
p. 39-45.
Yoshida, S. et al., 1994. Electromagnetic emission associated with frictional sliding of rock. In, “Electomagnetic phenomena
related to earthquake prediction”. Hayakawa, M. and Fujinawa, Y. (eds.), p. 307-322. Terra Scientific, Tokyo, Japan.
About the author: Dr. Arun Bapat worked as Head, Earthquake Engineering Research Division at the Central Water & Power
Research Institute (CWPRS) at Pune in India. His major contribution is the compilation of an earthquake catalogue in India. This
book has been published by the Indian Society of Earthquake Technology (ISET). He then started a new discipline of SeismoSedimentation. When a destructive earthquake occurs in the catchment area of a river, the sediments in the river and in any
reservoir increase; he has named them Seismo-Sediments. He has given a mathematical formula for calculating Seismo-Sediments.
Along with Canadian Tsunamologist Tad Murty he wrote a paper “Tsunami On Indian Coast”. This is the first paper on the
Tsunami in India. He had informed the authorities of the possible occurrence of a destructive earthquake in the Andaman and
Sumatra region four months prior to the Sumatran earthquake of Dec 2004. He has published about 155 research papers and about
550 popular articles on earthquake-related subjects. Presently he studies seismic related problems and works with several states in
India and with some neighboring countries such as Nepal, Pakistan, Indonesia, Mozambique, Seychelles etc. His current project is
earthquake prediction and seismic vulnerability of metro cities.
Editor’s comment: This paper, originally presented at the First India Disaster Management Congress, New Delhi, 29 Nov.
2006, came to the Editor’s attention during our studies on recent devastating earthquakes in Indonesia and other regions. The
Editor considers this paper, which describes the seismo-electro-magnetic effect and other various precursory phenomena, to
be of particular importance for those who are seriously interested in the science of earthquake prediction. Supported by
Blot’s energy transmigration and Shou’s earthquake vapor cloud concepts, this paper will herald a turning point for the
perception that catastrophic earthquakes are scientifically predictable.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
39
SOLID PLANETARY TIDES AND DIFFERENTIAL MOTION OF DEEP LAYERS
Lev A. MASLOV
Otero Junior College, La Junta, Colorado, USA
[email protected]
Vladimir A. ANOKHIN
Institute for Geology and Mineral Resources of the World Ocean,
St. Petersburg, Russia
[email protected]
Abstract: Regularities in orientation of faults and lineaments of the Earth’s crust as well as fractal statistics in spatial
distribution of faults and lineaments were studied. On the basis of this study it was assumed that the Earth’s crust and,
probably, lithosphere can be treated as comminuted scale-invariant hierarchical substances. Also, we proposed treating the
Earth’s material in a long-time and long-wave load approximation (Sun and Moon tidal deformations) as a loose substance.
Mathematical and experimental modeling of loose substance deformations demonstrated that the radial planetary tides are
being transformed into lateral differential motion of planetary layers. In the rotating coordinate system this differential
motion is characterized by the relative delay of the motion of layers. This phenomenon can be used to explain, along with
other conventional mechanisms, the westward drift of the lithosphere. The differential motion of planetary layers acts as a
mechanism providing shear heating and melting in deep layers thus participating in the generation of a planet’s magnetic
field.
Keywords: Earth, Moon, tides, loose substance, differentiated motion, westward drift, magnetic field
Introduction
ravitational interaction between the Earth and Moon, as well as between the Earth and Sun, is one of the strongest
and long-lasting factors in the Earth’s evolution. On the geological time scale, tidal deformations can be
considered as very long-wave (M2 and S2 tides) and high-frequency vibrations. This type of load suggests the
rheology is other than elastic, viscous, plastic, or a combination of them. The westward drift of the lithosphere relative
to the underlying mantle is a phenomenon first attributed to the Earth-Moon tidal torque as well as to mantle
convection, (Scoppola, Boccaletti, Bevis, at al., 2006). A strong correlation between planets’ magnetic moments and
their angular momentum suggests that there exists a mechanism that transforms the energy of rotation into a planet’s
magnetic field energy (Arge et al., 1995). This paper proposes a new rheological model for evaluating tidal
deformations and studies how tidal deformations can be transformed into the differential motion of deep planetary
layers. This approach will help us to explain both of these phenomena – westward drift of the lithosphere and the
strong magnetic field of some planets from one source, one basic mechanism – differential motion of deep planetary
layers.
G
Regularities in Orientation of Faults and Lineaments
The “orientation – number of lineaments and faults” rose-chart has been constructed by (Maslov and Anokhin, 2006),
Figure 1. Analysis of this chart revealed the existence of two global systems of faults and lineaments (F&L), System I
and System II, in the Earth’s crust. System I consists of F&L of N–S and E–W directions. System II consists of F&L of
NW–SE and NE-SW directions. The F&L Systems I and II include structures of different geologic times, from
Riphean grabens of the Russian platform and Ural fold belt, to the Alpine Rift of the Red Sea. These structures have
deep roots and are stable over geologic time. A schematic representation of the rose-chart directions of lineaments and
fractures is given in Figure 2a. It is seen here that there exists a bimodal distribution of System II F&L symmetrical
about azimuths ± 45o with deviations ≈ ±10-15o.
40
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 1. Rose chart of directions of lineaments and fractures (L&F). Azimuths of directions are given in degrees; radial
coordinate – the corresponding number of L&F. System I of lineaments and faults – solid lines. System II of lineaments and faults
– dashed lines.
Figure 2. Schematic representation of Figure 1 (a, b). Orientation of fractures in a specimen under extension (c) and compression
(d) according to Coulomb’s law of fracture.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
41
Mathematical modeling
Mathematical modeling of mechanical stresses caused by changes in the Earth’s ellipsoidal compression has been done
by Stovas (1963). The principal normal stresses caused by changes in the Earth’s ellipsoidal compression are oriented
in the N–S and E–W directions. The corresponding principal shear stresses are oriented in NE–SW and NW–SE
directions with azimuths of ± 45o. This is in remarkable agreement with the F&L systems shown in Figures 1 and
Figure 2a. The bimodal structure of this distribution can be explained using Coulomb’s Law of Fracture, Figure 2(b &
c). The change of the Earth’s ellipsoidal flattening, caused by variations in the Earth’s rotation, produces in the Earth’s
crust two systems of faults oriented at the angles A = 45 ± ϕ / 2 . For sand, this angle is 30o <φ < 35o, which is in
good correspondence with the bimodal structure of System II faults and lineaments,
Figure 2(d).
o
Regularities in Spatial Distribution of Faults and Lineaments
Spatial correlations of the faults’ characteristics (length - frequency, length - distance between faults, length magnitudes of displacements, distance between faults - thickness of the crust) were studied by Sherman (1977) for
Eurasia and the Baikal Rift Zone.
Correlation between the length of faults (L) and their quantity (N) per unit square for the Baikal Rift Zone:
N = 0.121 ⋅ L0.42
(1)
Correlation between the length of faults (L) and distance between them (D) for Eurasia:
D = 4.5 ⋅ L0.45
(2)
Correlation coefficient r = 0.7 ± 0.3.
Correlation between the length of faults (L) and amplitude (A) of the displacement along the faults in the Baikal Rift
Zone:
A = 0.08 ⋅ L0.77
(3)
Correlation coefficient r = 0.77 ± 0.22.
Correlation between length of faults (L) and their quantity (N) per unit square for Eurasia:
N = 0.052 ⋅ L0.40
(4)
Relations (1-4), graphed in the bilogarithmic coordinate system, represent straight lines with slopes reflecting fractal
dimensions of the statistical distribution of faults and lineaments. The range of variation of L in this study is three
orders of magnitude.
The fractal nature of the inhomogeneities in the lithosphere evidenced from seismic wave scattering was studied (Wu
and Aki, 1985); generalization of the numerous data on the fractal nature of the lithosphere was done by Turcotte
(1995).
Hierarchical Structure of the Earth’s Crust
Regularities in the orientation of faults and lineaments, and regularities in their spatial distribution imply that the
Earth’s crust and, probably, lithosphere can be considered as comminuted scale-invariant hierarchical substances.
Characteristic sizes of grains constituting these substances span several orders of magnitudes. From this point of view,
the material of the Earth’s crust can be treated in a long-time and long-wave approximation as a loose substance.
Role of Planets’ Rotation in Generating Their Magnetic Fields
Correlation between the angular momentum (L) and magnetic moment (M) of planets has been studied by Arge et al.
(1995). The correlation between the rotation of a planet and its magnetic field was also discussed in (Kosygin and
Maslov, 1990). Figure 3 demonstrates that there exists a strong correlation between angular momentum (L) and the
42
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
magnetic moment (M) of planets. How does rotation of a planet or star affect its magnetic field? The Table below
shows that a strong magnetic field is observed in fast-rotating and low-consolidated planets like Saturn and Jupiter
(liquid and gaseous planets), and in the Earth, the only terrestrial planet with low consolidation because of the tidal
deformations from the Moon and Sun.
Figure 3. Correlation between angular momentum (L) and magnetic moment (M) of planets (Arge, Mullan and Dolginov, 1995).
Planet
Rotation /
Revolution
Mercury
1.5:1
Venus
1:1
Earth
366:1
Moon
1:1 to the
Earth
Mars
669:1
Jupiter
10476:1
Saturn
24232:1
Table
Factors affecting generation differentiated
motion of layers in the model of loose substance
Tidal wave
Density and
Differential
Magnetic
Consolidation motion of
Moment of
layers
a Planet /
Magnetic
Moment of
the Earth
Very low
High density
Does not
<6.1e(-4)
velocity?
and high
exist?
consolidation
No tidal wave High density
Does not
<1.3e(-4)
exist?
50 cm of the High density
Centimeters/ 1.0e(0)
M2 wave
and low
year
consolidation
No tidal wave High density
Does not
1.6e(-8)
and high
exist?
consolidation
High density
Does not
2.7e(-5)
Low
and high
exist?
amplitude
(<0.02 of the consolidation
Earth’s tide
amplitude)
High
Low density
Strong?
2.0e(4)
amplitude?
and low
consolidation
High
Low density
Strong?
5.4e(2)
amplitude?
and low
consolidation
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
43
Mathematical modeling of the Differential Motion of Layers
The simultaneous differential equations modeling tidal deformations in a loose substance can be written in the form
(Revuzhenko, Chanishev and Shemiakin, 1985; Revuzhenko, 2006):
dx
= kx − ωy
dt
dy
= ωx − ky
dt
(5)
t is time, k and –k are rates of extension and compression along the x and y axes correspondingly, and ω is the
angular velocity of rotation of the load, Figure 4. The solution of this system is:
ω
⎛k
⎞
x = ⎜ C − C ⎟ sin λt + C cos λt ,
1
2
1
λ
⎝λ
⎠
k
⎛ω
⎞
y = ⎜ C − C ⎟ sin λt + C cos λt ,
1
2
2
λ
⎝λ
⎠
where λ = ω 2 − k 2 , Δω = ω − λ ≈
(6)
k2
, v = 2πΔωR , and v is the linear velocity of a particle.
2 ⋅ω
The trajectories of particles according to (6) are ellipses with eccentricity e =
( ω − k ) /( ω + k ) , and
period P = 2π / λ , which is greater than period P = 2π / ω . Figure 5(a) shows trajectories calculated for k = 4.0, ω =
10.0 and t = 2π / ω , so that Δω = 0.8 . The trajectories of particles in a coordinate system rotating with angular
velocity ω are shown in Figure 5(b). As is seen from Figure 5(a & b), there is a delay in circular motion of particles
relative to rotational velocity of the whole body. At the same time, there is no differential motion of layers in this
model; Δω is the same for any radius. For a real planetary interior, the coefficient of compression, k, can depend on
radius with its minimal values at the center of the Earth and maximum attained close to its surface. Mathematical
modeling of tidal deformations in a loose substance was done for the variable coefficient of compression, k , in
equations (5). Figure 5(c) shows trajectories of particles for
k = b ⋅ sin(r ) , r = sin( x(t ) 2 + y (t ) 2 )
(7)
0 ≤ r ≤ 1 , and t = 2π / ω in a non-rotating coordinate system. Trajectories of particles in a coordinate system
rotating with angular velocity ω are shown in Figure 5(b). In this case one can observe delay in circular motion of
Figure 4. Sketch of the Earth’s tidal deformations (a) and model of the “tidal” deformation of a loose substance (b).
44
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 5. Mathematical modeling of tidal deformations of a loose substance.
a. Trajectories of particles in a non-rotating coordinate system with initial positions on the x-axis for the model with constant
coefficient k; there is no differential motion of layers.
b. Trajectories of particles in a coordinate system rotating with angular velocity ω .
c. Trajectories of particles in a non-rotating coordinate system with initial positions on the x-axis for the model with the variable
coefficient k according to formula (7).
d. Trajectories of particles in a coordinate system rotating with angular velocity ω; differential motion of layers.
particles relative to the rotational velocity of the whole body as well as differential motion of the layers of a body.
Interpreting this result for the Earth, one can say that the planetary tidal deformations can produce the westward drift of
the lithosphere as well as a differential motion of deep layers. This mechanism can be additional to the tidal torque and
mantle convection discussed in the article by (Scoppola, Boccaletti, Bevis, at al., 2006). For the Earth’s rotation,
ω = 7.27 ⋅ 10 − 5 c − 1 , and the coefficient k averaged over the radius of the Earth is k = 3.63 ⋅ 10 − 12 c − 1 . In this
case the velocity of the westward drift of the lithosphere is approximately equal to 4 mm/year. If tidal deformations are
concentrated in a layer or in a series of layers of total thickness ≈ 600 km, then the westward drift of the lithosphere
can be about 40 mm/year.
Experimental modeling
The experimental simulation of “tidal” deformations of a loose substance has been done by (Revuzhenko, Chanishev
and Shemiakin, 1985; Revuzhenko, 2006). The experimental device consists of a rigid, slightly elliptical cylinder
rotating about a flexible cylinder filled with sand, Figure 6. As the outer cylinder rotates, it mimics the deformation of
the Earth due to the gravitational tidal deformations. Initially, a plane of black sand acting as a marker to describe the
motion of all particles bisects the ellipse all the way to the bottom of the cylinder. After a few rotations, deformation of
the black line of sand can be seen. After many rotations, a spiral structure appears in the black sand.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
45
Figure 6. The scheme of experimental device (a), and results of experimental modeling of tidal deformation of a loose substance
(b, c). The initial stage of the experiment (b). The black sand strip after more than 500 rotations of the outer cylinder (c)
(Revuzhenko, Chanishev and Shemiakin, 1985).
Conclusion
Study of orientation of faults and lineaments revealed the existence of two global systems of faults and lineaments in
the Earth’s crust, and in the lithosphere which is caused by the deceleration of the planet’s rotation and its variations.
Fractal statistics in spatial distribution of faults and lineaments allowed us to suggest that in a long-time and long-wave
approximation, the Earth’s material can be treated as comminuted scale-invariant hierarchical substance. One of the
mechanical realizations of this kind of substance is a loose substance. Mathematical and experimental modeling of
tidal deformations in a loose substance showed that the radial tidal deformations can be transformed into lateral
differential motion of planetary layers. This motion, as estimated, can be a significant part of the total westward drift of
the lithosphere. The differential motion can act also as a mechanism providing shear heating and melting of the mantle
and core material thus participating in the generation of a planet’s magnetic field.
Acknowledgements : We wish to express our gratitude to Sara Grace Burtwell for her careful reading of this manuscript,
valuable advice, and sincere comments which helped us to finish this study.
References
Arge, C.N., Mullan, D.J. and Dolginov, A.Z., 1995. Magnetic moments and angular momenta of stars and planets. The
Astrophysical Journal, v. 443, p. 795-803.
Kosygin, Yu.A., Maslov, L.A., 1990. Rotation of planets and their thermal and magnetic fields. Geotectonica et Metallogenia,
v. 14, p. 109 – 113.
Maslov, L.A. and Anokhin V., A., 2006. The Earth’s decelerated rotation and regularities in orientation of its surface lineaments
and faults. Planetary and Space Science, v. 54, p. 216-218.
Revuzhenko, A.F., 2006. Mechanics of granular media. Springer-Verlag, Verlin Heidelberg.
Revuzhenko, A.F., Chanishev, A.I. and Shemiakin E.I., 1985. Matematicheskie modeli uprugoplasticheskih tel (Mathematical
models of the elasto-plastic materials). p. 108-119. In: Pressing problems of computing mathematics and mathematical
modeling. Russian Academy of Science, Siberian Branch, ComputingCenter. Novosibirsk (In Russian).
Sherman, S.I., 1977. Fizicheskie zakonomernosti razvitia razlomov zemnoi kori (Regularities in the surface distribution of the
Earth’s crust faults and lineaments). Novosibirsk, Nauka, 102 p. (In Russian).
Scoppola, B., Boccaletti, D. and Bevis, M., et al., 2006.The Westward drift of the lithosphere: A Rotational Drag? GSA Bull.
v. 118, p. 199-209.
Stovas, М.F., 1963. Nekotorie voprosi tektogeneza (Some problems of tectogenesis). In: Problemi planetarnoi geologii.
Gosgeoltehizdat, p. 222-274, Moscow (In Russian).
Turcotte, D.L., 1995. Scaling in Geology: Landforms and Earthquakes. Proc. Natl. Acad. Sci. USA, v. 92, p. 6697-6704.
Wu, R.S. and Aki, K., 1985, The fractal nature of the inhomogeneities in the lithosphere evidenced from seismic wave
scattering. Pure and Appl. Geophys., v. 123, p. 805-818.
46
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
TECTONIC CONTROLS OF CLIMATE
Cliff OLLIER
School of Earth and Geographical Sciences, The University of Western Australia
Crawley, WA 6009, Australia
[email protected]
Abstract: In his excellent account of the Greenhouse-Global Warming bandwagon Bhat (2006) pointed out that many factors other
than CO2 affect the world’s climate, including tectonics. He mentioned the influence of geothermal heat of submarine eruptions
affecting water temperatures, and the possible match of patterns in climate and sea floors. The tectonic-climate theme is also
treated by Leybourne et al. (2006), mainly concerned with thermal effects of submarine earthquakes. Other NCGT papers with the
climate theme are Endersbee (2007), who stresses cosmology rather more than tectonics, and Ollier (2007) who deals with tectonic
and climatic associations of glaciers and ice-sheets. From amongst the many aspects of tectonics that influence climate, this paper
concentrates on mountain uplift and continental re-distribution. In the past few million years, world wide uplift of mountains in the
Neotectonic Period has actively forced climatic change. In particular the uplift of the Tibet Plateau and its bordering mountains had
global effects through the Asian monsoon, jet streams, and inter-hemisphere exchange. The hypothesis of the negative greenhouse
effect is not supported by the dating of climatic change, or relationship between carbon dioxide, weathering and erosion.
Supercontinents such as Pangaea had very different climates from the smaller continents of today. Antarctica has been long
isolated by the Antarctic Circumpolar Current and does not share the same tectonic and climatic history as the rest of the world.
Keywords: climate, Neotectonics, negative greenhouse, monsoon, continental drift, Antarctica isolation
INTRODUCTION
I
n his excellent account of the Greenhouse-Global Warming bandwagon Bhat (2006) pointed out that many factors
other than CO2, including tectonics, affect the world’s climate. He mentioned the influence of geothermal heat of
submarine eruptions affecting water temperatures, and the possible match of patterns in climate and sea floors. The
tectonic-climate theme is also treated by Leybourne et al. (2006), who are mainly concerned with thermal effects of
submarine earthquakes.
Here I review some other aspects of the relationship between tectonics and climate, especially the links between
continental movement and climate, and between mountain building and climate. In doing so I have also to refute some
widely circulated ideas that relate carbon dioxide to tectonics and climate.
Traditionally solar energy was seen as the main controller of climate, and climatic variations were seen as resulting
from astronomical events, such as the Milankovich cycles and sunspot cycles. Other factors such as tectonics and
ocean currents were regarded as minor contributors. Such diverse features as volcanic eruption of gases, dust and
aerosols, wetlands, rainforests, cosmic rays, and more also have a role. Only in recent times have changes in
greenhouse gases, especially CO2, been seen as an overwhelming factor, and I suspect this over-emphasis is an
example of the seductive scientific fallacy of the single cause.
Even if it is accepted that astronomical causes affect minor cycles, the cause of the major changes, such as initiation of
ice ages, remains controversial. Some (on the present bandwagon) advocate changing CO2 content of the atmosphere,
others changes in distribution of land and sea associated with plate tectonics, and still others the effects of mountain
building. We can also use the process in reverse, and see how evidence of past climates can be used to work out the
tectonic activity.
DIRECT EFFECTS
When new mountains appear they have a direct effect on local climate, and the impact grows as mountains increase in
elevation and area. Large volcanoes are the obvious example, with Kilimanjaro, Africa’s highest mountain, able to
have an ice cap, and many large volcanoes inducing rain shadows and similar climatic effects.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
47
Climate and tectonic uplift
When pre-existing lowlands are uplifted to form plateaus they will also induce new climates. For example, Partridge
(1998) wrote: “Uplift of 1000 m [in southern Africa] is equivalent, in its effects on surface temperatures, to the cooling
experienced during an Ice Age in higher latitudes”. He thinks the close coincidence of South African uplift with a
global period of cooling and increasing aridity between 2.8 and 2.6 Ma would have amplified its effects.
In principle the snowline is at high altitude at the equator, and progressively lowers towards the poles. The timber line
and other climatic indicators follow at a lower elevation. Fleming (1979) documented timberline and snowline changes
between Antarctica and New Guinea via New Zealand. His diagrams show the location of the snowline at different
times (Fig. 1).
The climatic zones at sea level in mid-Tertiary time are based mainly on marine evidence, because at this stage New
Zealand and New Guinea had hardly appeared above sea level. In the Pliocene the climatic zones were almost
unchanged at sea level, but New Zealand and New Guinea had grown higher, reaching different climatic zones. By the
time of the last glaciation the islands had achieved their full present height, and furthermore the climatic belts had
moved, producing extensive glacial and alpine zones in the islands. The uplift of New Zealand and New Guinea clearly
had a dominant effect on their climate in the Pleistocene.
The climatic gradients determined from New Zealand and New Guinea cannot account for the situation in Australia. If
Fleming’s snowline is drawn across Australia it is evident that Australia is high enough to have been glaciated
throughout the Quaternary cold periods. Yet mainland Australia experienced only the last glaciation. Australia was not
high enough during earlier glaciations, supporting the idea of Neotectonic uplift in the late Quaternary (Ollier, 1986).
Weathering and Negative Greenhouse Effects
Ruddiman and his colleagues (Ruddiman and Kutzbach, 1991; Raymo and Ruddiman, 1992; Ruddiman, 1997) have
been major proponents of the hypothesis that mountain building controls climate through a negative greenhouse effect.
Their hypothesis is widely taught in the US, and has been repeated by others, such as Hay (1996). The proposal may be
summarised as follows:
Increased tectonic uplift over the last 40 million years leads to greater erosion and weathering. Weathering of rocks is
by carbonation and removes carbon dioxide from the atmosphere. The reduction in carbon dioxide causes a negative
greenhouse effect and leads to global cooling, and eventually to glaciation.
I believe there are three major misconceptions in this proposed interrelationship of erosion, weathering and carbon
dioxide.
1. Erosion and chemical weathering are two different processes that do not necessarily occur together. Erosion can
proceed, as it often does in mountainous regions, with little chemical alteration of the rock or mineral fragments that
are loosened and transported. Indeed, immature (so-called labile) sediments with large amounts of unweathered
mineral and rock fragments are generally assumed by sedimentologists to be derived from the rapid erosion of
mountains.
2. Weathering is not synonymous with carbonation, that is, the interaction with CO2. Raymo and Ruddiman (1992) use
the following simple formula:
Chemical weathering
CaSiO + CO2 → CaCO3 + SiO2
In words, a calcium silicate plus carbon dioxide produces calcium carbonate and free silica.
This oversimplification is found in many elementary texts, but is incorrect. In most situations hydrolysis is by far the
most important process of silicate weathering (Ollier, 1984; Trescases, 1992; Eggleton, 1998).
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 1 – Changes in the snowline and timberline elevation with latitude, and its variation through time (after Fleming, 1979). The
horizontal scale is diagrammatic. a. mid-Tertiary; b. Pliocene; c. Last Glaciation; d. Present; e. Present, with Australia fitted on to
the Fleming snowline (after Ollier, 1986). For explanation see text. A = Antarctica; NZ = New Zealand; AUS = Australia; NG =
New Guinea.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
49
Eggleton wrote “During weathering protons are added to the solid phases as other cations and oxygen are lost in
solution”.
The following is one of the formulae provided by Eggleton:
2KAl2[Si3Al] O10(OH)2
+
Muscovite
4H2O
→
water
3Al2Si2O5(OH)4
+
K2O
kaolinite
Ollier (1984) represents the weathering of an aluminosilicate mineral as follows, where M represents any metal ion and
SiO represents any silica group:
MalSiO
Al-silicate
+
H2O
water
→
M+
cation
+
HalSiO
clay
+
OHhydroxyl ion
It is important to realize that weathering produces clays, not carbonates.
The real-world evidence from deep chemical weathering seems to be the exact opposite of that postulated by
Ruddiman and colleagues. The greatest deep weathering profiles all around the world are of Mesozoic or early Tertiary
age. This was a period of broad plains with little mountain building. Since then uplifted plateaus have been associated
with stripping of the old regolith to make etchplains (Ollier, 1992, Ollier and Pain, 1996). In general there appears to
have been a reduction in chemical weathering since the mid- or early Tertiary, and today deep chemical weathering is
confined to the humid tropics.
3. A further problem arises from Ruddiman’s erroneous time scale. Originally Ruddiman and Kutzbach (1991) wrote:
“Prior to 40 million years ago most of the world was warmer and wetter than it is now”. “During the past 40 million
years, and particularly during the past 15 million years, this warm wet climate largely disappeared.” And “Significantly
the three rivers that currently carry the highest loads of dissolved chemicals into the ocean… all drain regions that have
been uplifted in the past 40 million years”. They repeatedly stress 40 million years. They maintained that uplift of
Tibet, the highlands of western North America such as the Colorado Plateau, and the Andes started about 40 million
years ago. But the Cenozoic ice-Age is essentially a Quaternary event, with precursors in the late Neogene. Glaciation
in the northern hemisphere started about 3 million years ago (Imbrie and Imbrie, 1979). Mountain building 40 million
years ago, or even 15 million years ago, would seem to be a remote relationship. Their suggested timing now seems
wrong, and they were not aware of widespread young uplift in many other parts of the world. The connection between
climatic cooling and mountain building is correct in principle, but a time scale of 5 million years, not 40 million, seems
more probable.
THE NEOTECTONIC PERIOD AND GLOBAL CLIMATIC EFFECTS
Ollier and Pain (2000) assembled evidence that most mountains are the products of uplift of a plain to form a plateau,
which may or may not be extensively dissected. This is regardless of the internal rock structure – horizontal, folded,
metamorphic or granite. The age of a mountain or mountain range is thus the age of plateau uplift, not the last age of
folding of rock. On this basis there is a preponderance of uplift in the last few million years, and this is a global
phenomenon. It affects so-called Alpine mountains, mountains on active or passive continental margins, and mountains
in deep continental interiors. The period of uplift is known as the Neotectonic Period (Ollier and Pain, 2000). Earlier,
Mörner (1992) wrote “an important neotectonic-paleoclimatic linkage is hereby advocated”. Zhu (1997) also believes
there is a coupled climatic-tectonic system, because of the close relationship between climatic change and neotectonic
movement. According to him the first uplift of the Tibet Plateau occurred between about 3.5 and 2.4 Ma. Ollier and
Pain (2000) proposed that since the Neotectonic Period coincides roughly in time with the Cenozoic ice age, perhaps
orographic change actually caused the climatic change. If the uplift of Tibet, the Andes and many other highlands
occurred mainly in the Pliocene and Pleistocene the correspondence between uplift and climatic change is much greater
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
than Ruddiman and his colleagues proposed. The orographic time scale matches the glaciation time scale much better
than the 40-20 Ma of Ruddiman and colleagues. The correspondence of Tibetan uplift with the onset of the monsoon
climate and the deposition of loess is the best example of detailed correlation, so will be reviewed in a little more
detail.
Gansser (1991) wrote: “... we must realize that the morphogenic phase is not only restricted to the Himalayas but
involves the whole Tibetan block. This surprising fact shows that an area of 2,500,000 km2 has been uplifted 3-4,000 m
during Pleistocene time and that this uplift is still going on. In places the uplift rate is 4.5 mm/y (five times the
maximum in the European Alps).”
From the Pliocene to the early Quaternary (5-1.1 Ma) the Kunlun Pass area of the Tibetan Plateau was no more than
1500 m high and the climate was warm and humid (Wu et al., 2001). “The extreme geomorphic changes in the Kunlun
Pass area reflect an abrupt uplift of the Tibet plateau during the Early and Middle Pleistocene. The Kunlun-Yellow
River tectonic movement occurred 1.1-0.6 Ma”. Zheng et al., (2000) concluded from sediments at the foot of the
Kunlun Mountains that uplift began around 4.5 Ma. For the Himalayas, Gansser puts the uplift as Pleistocene.
Japanese workers on the Siwaliks, deposits in a sedimentary basin filled with erosion products from the Himalayas,
found that fine sediments give way to a boulder conglomerate at about 1 million years, indicating a time of major uplift
(Prof. T. Kosaka, pers. Comm.).
The Tibet plateau area had two earlier uplifts in the middle Eocene and early Miocene, recorded in planation surfaces.
The strongest uplift of the plateau and its bordering mountains, the so-called Qinzang (Tibet) movement, occurred
between 3.6 and 1.7 Ma (Li et al., 1996) and had three phases commencing:
A. 3.6 Ma
B. 2.5 Ma
C. 1.7 Ma
It was phase B of the Qinzang movement at 2.6 Ma that raised the plateau to the critical height of 2,000, triggering the
onset of the monsoon and loess deposition. Phase C of the Qinzang movement at 1.7 Ma caused a large
geomorphological adjustment and produced the present geomorphic configurations including the large rivers such as
the Huang He and the Chang Jiang.
Still later movements are the Kunlun-Huang He (or Kunhuang) movement which occurred between 1.1 and 0.6 Ma,
and the Gonghe movement which occurred after 0.15 Ma (Li and Fang, 1999). The Kunhuang movement lifted the
plateau to an average height of 3,000 m with mountains to over 4000 m, a critical height for glacial development.
Since then the plateau has undergone several glaciations. The Gonghe movement raised the plateau to its present
height. The Himalayas rose to over 6000 m and became a major barrier for the inflow of the Indian monsoon onto the
Plateau, leading to further drying of northwestern China.
The Quaternary uplift of the Tibet Plateau and the Himalayas introduced a powerful new geographical factor in the
pattern of global climate. In the Early and Middle Pleistocene when the average elevation of the Himalayan range was
about 4400m, the evidence from interglacial deposits shows that the north side was as warm as the south side at similar
elevations. The uplift of the range to its present 6000m average elevation made the Himalayas a much more effective
climatic barrier, preventing warm, moist air from entering the Tibetan Plateau.
Even plate tectonic workers recognize the climatic effects of young mountains. Buslow et al. (2006) accept the widely
believed, but to me incredible, idea that tectonic forces can be transmitted enormous distance: “The driving force for
this tectonic deformation [Central Asian mountains] were transmitted over great distances from the Indo-Eurasian
collision zone.” Nevertheless they acknowledge that “The Cenozoic building of the vast Central Asian intracontinental
mountain system changed regional and even global atmospheric circulation, positioned a huge area above the snowline, increasing solar reflection, and ultimately resulting in climatic cooling. In particular since the Late Pliocene the
high mountains became an effective barrier between cold northern Eurasian and warm southern airflows primarily
from the Indian Ocean.” (My italics) Of course the main alleged collision was long before the Pliocene.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
51
MONSOON EFFECTS
The monsoon is a climatic type characterized by major wind reversals. Monsoon-type wind and seasonal changes are
found in several continents, but the Asian one is the most intense and has global impact. Much of the literature
concerns the Indian Monsoon, but the East Asian Monsoon may be even more significant. This monsoon is related to
the deposition of wind-blown loess in China, and this uniquely stratified material provides a splendid record of climatic
change.
On a homogenous globe the planetary circulation would be the same in both hemispheres, but because there is more
land in the northern hemisphere, the two hemispheres have different circulation. The northern hemisphere has greater
seasonal contrast. The southern circulation is more vigorous, and when the thermal equator migrates northwards in
June and July the southern hemisphere circulation is able to encroach over the equator. In the reverse season migration
of the inter-tropical convergence zone into the southern hemisphere is limited.
Besides the winds near the ground, which constitute the monsoon, the atmosphere is affected by jet streams at higher
level. They flow generally from west to east, but the location of the principal jet streams appears to be substantially
influenced by the topography of the Tibet Plateau and its associated mountains. Since the jet streams mainly occur at
an elevation of about 10 km and the mountains only rise to half this elevation, it is not direct topography but possibly a
thermal high over Tibet that deflects the jet streams. One jet stream occupies a position just south of the Himalayas and
another skirt around the north of the Tibetan Plateau. These two jet streams become confluent east of the Himalayas in
China. In spring the westerlies begin their northward seasonal migration. The northerly jet stream intensifies at the
expense of its Himalayan counterpart, but they both retain their mean geographic location because of topographic
constraints. The southern jet stream declines until finally, over a period of a few days it disappears, and the summer
monsoon of India finally advances. In late September or October the equatorial trough of low pressure weakens and
retreats south. At high level the Himalayan jet stream reappears rather suddenly in mid-October.
Fang et al. (1999b) provide a detailed explanation of the monsoon climate, and their map (Fig. 2) shows the location of
the westerly jets. The pattern is clearly influenced by the Tibetan block. They say that uplift of the Tibet Plateau not
only generated the Tibetan Plateau monsoon, but also intensified the northern hemisphere temperature gradient. Fang
et al. (1999a) further suggest that before the uplift of the Tibet Plateau there was a single jet stream with a course right
across the position of the present plateau (Fig. 3). The final uplift that caused the last change in winds (and a change in
the composition of loess) occurred about the Bruhnes-Matuyama magnetic reversal, about 800,000 years ago.
Manabe and Terpstra (1974) claim that upheaval of the Plateau essentially created the monsoons of east and south
Asia. Once monsoon conditions existed, exclusion of the Indian monsoon made the north side of the Plateau colder and
drier and this restricted the growth of glaciers. Liu and Ding (1998) described the palaeo-monsoon as determined from
the loess record. In the past 2.6 million years the palaeo-monsoon record can be divided into 166 events. The
monsoonal rainfall belt has experienced a wide, repeated advance-retreat change during the glacial-interglacial cycles
of the Pleistocene. Both temporal and spatial changes of the monsoon system in the Quaternary can be linked closely to
global ice-volume relationships. It therefore seems that although uplift of the Tibet Plateau may be vitally concerned
with the onset of the monsoon, minor variations are controlled by orbital variations.
They also stress the important feature that the monsoon links the low pressure cell over the Tibet Plateau (India Low)
to both the Pacific High and the Australia High, leading to inter-hemispheric temperature exchange, and so plays a part
in global climate changes. “Because the winter monsoon originates in the high latitudes of the Northern Hemisphere
and can transfer climatic signals to low latitudes and even across the equator, we speculate that it may have played a
part in the inter-hemispheric connection of climatic changes”. Inter-hemisphere interaction might also work the other
way, and some authorities have concluded that the annual pattern of the southern circulation is fundamental to the
precise timing and extent of the Asian monsoon.
It must be noted that some authors suggest different timing and mechanisms. Roe et al. (2004) claim a “very significant
increase in the deposition of windblown dust in the region around Lanzhou, China, at around 7 – 8 million years ago.”
They relate it to the “onset of glaciation in Greenland at around the same time” and topographic development.
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 2 – Maps of Tibet showing the variations of the jet streams associated with the East Asian Monsoon (after Fang et al.,
1999a). a. July, Summer monsoon (northern hemisphere); b. January, Winter monsoon. The shaded area is bounded by the
3000 m contour.
Figure 3 – The jet stream over and around Tibet, before and after uplift (after Fang et al., 1999b). a. Before 800 000 years ago;
b. Since 800 000 years ago. The shaded area is bounded by the 3000 m contour.
CONTINENTAL DRIFT AND CLIMATE
Most, but not all, geologists believe in some form of continental drift. In older versions the continents simply moved
across the globe, with fragments like Africa and South America moving apart. Some have two original supercontinents
– Gondwanaland and Laurentia, some have a single supercontinent, Pangaea. Expanding Earth proponents such as
Carey (1976) and Maxlow (2005) suggest a single sialic layer covering an early, smaller globe that split up with the
creation of ocean basins as new sea floors appeared.
How would the drift of continents affect climate?
1. It must be realized that the climate on a supercontinent would be different from that of today’s smaller continent
(Ollier, 1992). The average distance to the sea would be greater, which in theory might cause more continental-type
climates. At average gradients inland from the coast, the centre of a supercontinent would be higher than the centre
of a small continent. Major rivers would be longer, and so their average gradients would be lower, and their erosive
power reduced. There is a possibility that temporary storage of sediment on land would be greater. Lower erosion
rates could lead to greater accumulation of weathering products, and with increased continental sedimentation there
might be greater development of regolith than occurs on today’s small continents.
2. The rearrangement of continents would change ocean currents, vital in the transfer of energy, and so affecting
climate in different ways, like the Gulf Stream warming western Europe or the Circum-Antarctic current isolating
cold Antarctica.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
53
3. Climate could change if a continent changed latitude. If continents moved east-west, as supposed for Africa and
South America, the climate may not change significantly. But if a continent changes latitude significantly it should
change climate dramatically. If India really drifted north at a rapid rate to collide with Asia – a basic proposal of
plate tectonics – then it moved from a southern hemisphere climate across the equator to a northern hemisphere
climate. Each part of India must have crossed the equator at some time and experienced equatorial climates.
Australia was once adjacent to Antarctica, and the fit is so good that it remains a real challenge to those who deny drift.
The two continents drifted apart, but Antarctica remained fairly static and most of the movement was by Australia (and
the mid-ocean spreading site between Australia and Antarctica) drifting north. The track of movement is revealed by
the sea-floor spreading stripes and palaeomagnetic readings. On this basis one might expect Australia to move from a
cold climate to a hot one as it drifted towards the equator. In fact the climatic record, as deduced from palaeontology,
palaeosols and other surrogate records suggests that the climate was warm and wet through much of the time, and
aridity only set in after Australia had reached its present latitude.
We cannot even assume that past climates had a latitudinal variation like the present climate. In much of the
Cretaceous and certainly in the Eocene the whole world had a warm and wet climate (Walker and Sloan, 1992). It is
very hard to explain this. A greenhouse effect should warm the whole world, but the evidence suggests the equatorial
regions were about as hot as today, but the rest of the world was warmer, and there were no ice-caps on Earth.
The conventional plate tectonic story has all the continents assembled as the supercontinent Pangaea, and the
remainder of the globe covered by a single ocean, Panthalassa. The possible climate of such a world is seldom if ever
commented on, but it seems that it should be extreme. Oceanic modification of climate could be confined to the
relatively small rim of Pangaea, and the interior of the continent should be of very ‘continental’ character, depending
perhaps on the latitude. The known features of Jurassic palaeogeography and climate do not seem to match this
prediction, and in the Cretaceous, when sea floor spreading was still not very advanced, the world’s climate was
especially uniform.
If we look at the expanding Earth scenario, even more changes might be expected. The Earth’s climate is driven
basically by rising hot air at the equator and sinking air at the poles. On the present Earth the scene is complicated by
turnover in mid-latitudes to form the Hadley cells, so vital in today’s climate. On a smaller Earth there may have been
no Hadley Cells, and there might have been simply polar and equatorial climates. This might explain the rapid
alternation of glacial deposits and warm-climate dolomites found in several Precambrian deposits.
ANTARCTICA AND CLIMATE
The climatic and tectonic history of Antarctica is so different from the rest of the world that it places important
constraints on all global hypotheses of mechanisms controlling climate. It differs from the rest of the world in having a
very much longer history of glaciation. To develop a large ice-cap it is necessary to have large precipitation. The
climate of the present day probably could not grow an ice cap, and our major ice caps have to be inherited from a
previous situation which combined high precipitation with low temperatures in high latitudes. Furthermore, only when
sea-ice has grown quite large does it have a significant effect on ocean temperatures, which then helps to sustain an ice
age. The cause of glaciation is debatable, as is the time of its initiation. Studies of marine sediments indicate that
Cenozoic Antarctic ice sheet activity dates back to 45 Ma, and continental scale glaciation to about 40-36 Ma
(Hambrey et al., 1989; Cooper et al., 1991).
Glaciation started about the Eocene-Oligocene boundary, at about 34 Ma according to Deconto and Pollard (2003). In
the seventies Kennet and others proposed that climate cooled and an Antarctic ice sheet developed as the Antarctic
Circumpolar Current (ACC) increasingly isolated Antarctica from warm surface circulation of the Southern
Hemisphere oceans (see Kennett, 1977). This current originated as Australia and other southern continents drifted
north from the stationary Antarctica. The vital breaks were the opening of the Tasman Gateway between Australia and
Antarctica in the latest Eocene about 37-33.5 Ma (Exon et al., 2000) and opening of the Drake Passage in the earliest
Neogene (Lawver et al., 1992) (Fig. 4).
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Deconto and Pollard (2003) propose an alternative hypothesis; that the Antarctic cooling is caused by changes in
atmospheric CO2. This seems unlikely because Antarctica would require a different atmosphere from the rest of the
world for 30 million years. A major debate concerns whether the Transantarctic Mountains experienced uplift since
early or middle-Pleistocene (Behrendt and Cooper, 1991), or whether the mountains have remained at their present
level since the Miocene (Kerr et al., 2000). In either case Antarctic glaciation commenced well before major uplift.
It should be noted that only Antarctica is exceptional. Glaciation elsewhere in the southern hemisphere, such as New
Zealand, South America and Australia coincides roughly with that of the northern hemisphere, apart from some early
Oligocene mountain glaciation in Tasmania, which was then close to Antarctica (Macphail et al., 1993).
Figure 4 – Evolution of the Antarctic Circumpolar Current (much simplified after Lawver et al., 1992. a. 50 Ma middle Eocene;
b. 30 Ma Early Oligocene; c. 20 Ma Early Miocene.
CONCLUSIONS
The Neotectonic Period saw many mountain regions arise in the past few million years. This had major effects on
climate through several mechanisms, especially geographic cooling and the creation of the monsoon system, but not
the negative greenhouse effect. Seafloor spreading isolated Antarctica, which with development of the Antarctic
Circumpolar Current caused Antarctica to have a different tectonic and climatic history from the rest of the world.
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Ollier, C.D., 1992. Global change and long-term geomorphology. Terra Nova, 4: 312-319.
Ollier C.D. and Pain C.F., 1996. Regolith, Soils and Landforms. Wiley, Chichester.
Ollier C.D. and Pain, C.F., 2000. The Origin of Mountains, Routledge, London.
Ollier, C.D. 2007. Glaciers and ice-sheets: modern problems and tectonic associations. New Concepts in Global Tectonics, 42,
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Partridge, T.C., 1998. Of diamonds, dinosaurs and diastrophism: 150 million years of landscape evolution in southern Africa.
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SHORT NOTES
GLOBAL SHEAR DEFORMATIONS
Howard F. DE KALB
15 Hina Street, Hilo, HI 96720, USA
[email protected]
Abstract: A map set containing most of the World continental areas will be published in several issues of the NCGT Newsletter.
The first two maps in this issue show the Pacific Ocean. These maps are Mercator Projection and show shorelines, lakes and rivers
with an overlay of the Earth’s rotational shear deformation lines. Discussion includes a comparison of the shear lines and the Earth
features. A few suggestions are also presented of possible mechanisms that could produce some of the comparisons. The maps
represent a first look at the shear deformations, and comments both pro and con will be appreciated.
Keywords: geology, tectonics, shear, lineation
INTRODUCTION
A
ll unsymmetrical rotating bodies, including the Earth, are subject to shear forces. The classic definition of “Pure Shear”
is to give a hollow cylinder a slight twist, and then open it out on a flat surface. The upper and lower sides of a unit
square on the surface will be deformed by slipping in opposite directions, resulting in a shear rhombus with its sides and
diagonals maintaining straight lines. This definition of pure shear is also true for the Earth if the globe is first transformed by
Mercator Projection into a cylinder. The shear rhombus can be further subdivided repeatedly by one-half, centering on the
intersection of the diagonals. This results in a grid which can be fitted to Earth features by trial and error, giving the
following angles for the shear rhombus: Sides North 7.2° East and West 1.8° North; with diagonals North 40.5° West and
North 50.5° East. For discussion purposes these angles will be called directionals and shortened to N7E, W2N, N40W, and
N50E. This grid has been placed as an overlay on a Mercator USGS world map, and the East and the West Pacific portions
are discussed below. Discussion is restricted to comparing shear deformation with Earth features. It should also be kept in
mind that the maps are working copies, and that your comments will be appreciated. Maps of other parts of the world will
appear in future editions.
EAST PACIFIC
In the East Pacific two areas dominate; The Arctic north Aleutian area, and in the Mid Pacific the large group of faults
stretching from the west coast of the Americas to the central Pacific. In the extreme north is the Bering Strait that divides
Russia from Alaska. To the west is the Chukchi Peninsula in Russia with coasts lined up on the orthogonal shear diagonals
N40W and N50E, and to the east the Kotzebue Sound in Alaska, with its coasts also lined up on the shear diagonals.
Although the two are separated, the Russian Peninsula could fit neatly into the Alaskan Sound. Could it be that at one time
the two were joined, and that later the west half of the Pacific dropped as a result of a shock of some kind? It is interesting to
note that the distance from the Aleutian west end to the Chukchi Peninsula approximates the distance from the Aleutian east
end to the Ketzebue Sound. If they were conjoined at one time, the location could represent a center for the Aleutian Arc.
Further south we see five of the major faults emanating from the Americas along N2W. They are equally spaced and spring
down as they extend west. A directional shear line can be drawn starting from the juncture of Kamchatka and the Aleutian
west end along N40W following the Emperor Trough. The line truncates the upper three faults, Mendocino, Murray, and
Molokai on the west, ending in the main Hawaiian Islands. It appears that the shear deformation is on top of the fractures. As
in the case of the Chukchi Peninsula, it looks as if the west half of the Pacific may have dropped carrying the west ends of
the faults with it. The Hawaiian Island Chain follows the directional shear lines N40W and W2N in stair step fashion. This
can be seen more clearly in the book “The Twisted Earth.” Moving up the Hawaiian Chain to the Murray Fault, it breaks at
the Hawaiian Chain. Across the chain is the Necker Ridge which lies on N50E for a short distance where it joins Christmas
Ridge and the Line Islands along N40W to truncate the Clarion and Clipperton Faults. It is again stressed that observations
are only those related to a broad comparison of shear deformations and topographic features. Further work would require
much more information.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 1. East Pacific
57
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
WEST PACIFIC
The West Pacific area has a character completely different from that of the east. On the west are some of the largest
islands in the world, and many scattered small islands, often chained together along a directional shear line. Here also are
many of the world’s sub sea trenches and inland seas. Starting in Kozebue Sound, Alaska, and the Russian Chukchi
Peninsula is a wide band trending N50E, offset at Kamchatka, and containing many islands and inland seas, then ending at
the Tai Peninsula. Within the band on the east are the Kuril Islands, South Japan, and Taiwan. On the west is Kamchatka, a
portion of the Okhotsk Sea, the Sea of Japan, Korea, and The Yellow Sea. In the Japanese area the N50 E band is cut by a
N7E directional containing Sakhalin Island and North Japan. In the south, the Thai Peninsula is bounded by orthogonal shear
diagonals N50E and N40W forming a perfect rectangle. The area to the east and south of the Tai Peninsula shows some
confusion in the directional grain. On the east, Borneo’s northwest coast traces N50E, while to the south both the Malay
Peninsula and Sumatra trace N40W, with eastern Australia bounded by N40W directionals. Eastern Indonesia trends W2N.
As with the Thai Peninsula, New Zealand also clearly shows both the orthogonal shear diagonals N40W and N50E. Borneo
shoots out two N50E horns towards the Philippines cutting it into three parts. On the north the trend is N7E, and in the center
N40W, while in the south it trends generally N7E. Could it be that whatever shock might have caused slippage down the
center of the Pacific could also have caused the confusion of directionals within the Southeast Asia area?
South China is an area that does not seem to conform to the directional shear pattern. Its southeast coast traces a large portion
of a circular arc that approaches half of a circle, while the close packed rivers to the west seem to trace another portion of
that circle. That would put the center near Wuhan and its lakes, and the mouth of the Yangtze Gorge to the west. On the
surface, the area has the characteristics of an impact. Could it be that an impact in south China could have created the shock
that split the Pacific and caused the directional shear confusion within Southeast Asia? As with other quick looks, much
additional information would be required to advance any research
REFERENCE
DeKalb, H. F, 1990. The Twisted Earth. Lytel Eorthe Press, Hilo, HI, USA. 156p. (See also NCGT Newsletter no. 40,
p. 39-41)
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 2. West Pacific
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
SOUTH AMERICAN PACIFIC MARGIN
AS KEY TARGET FOR GEOSCIENCES AND GENERAL CULTURE
Giancarlo SCALERA
INGV – Istituto Nazionale di Geofisica e Vulcanologia, Roma, Italy
[email protected]
Abstract: Analysis of a relocated hypocentres database and of a global volcanic eruptions catalogue has made clear that the South
American Pacific margin is a site of peculiar phenomena and related geophysical events.
The already known maximum rate of deep earthquakes, the expected mean recurrence time of extreme magnitude
earthquakes of a few tens of years, and the closeness of the region to the Nazca triple point – i.e. the region with the maximum rate
of sea floor expansion – mean that the Andean margin deserves priority in preparing stable geophysical instrument arrays in
anticipation of the next great earthquake, with the aim of increasing our understanding of the real nature of earthquakes, of the real
geodynamics of active margins, and of global geodynamics and tectonics.
Keywords: South American Pacific margin, great earthquakes, eruptions rate, active margin interpretation, global geodynamics
A
number of clues coming from historical and recent data converge toward the necessity of a reinterpreting both
so-called subduction zones and the associated orogenic arcs (Scalera, 2007a & 2007b).
An unavoidable indication of prevailing surfaceward movements of mantle materials comes from analysis of polar
motion in the case of the great Sumatran ‘subduction’ earthquake (Scalera, 2005b, 2006c & 2007b). A similar
indication came from the correlation between eruption and great earthquakes recognizable along the Andes region
(Figure 1). Although observational data from a long supplemental period of time is needed, a common cause of both
earthquakes and eruptions can be envisaged in episodic mantle material movements.
The 3-D plots of the hypocentral locations of a number of Wadati-Benioff zones reveal that planar or spoon-like
distribution of intermediate and deep hypocenters is not a normal characteristic pattern (e.g. Figure 3). The hypocentres
spatially distribute on groups of elongated clusters or filaments that taper downward. ‘Single filaments’ can also be
recognized beneath the Messina Strait – Southern Tyrrhenian Sea – and the Vrancea region. No subduction process can
produce such a pattern, which can be more easily ascribed to an upward transport of matter and energy sensu lato
(Scalera, 2005b).
As a consequence of the preceding clues, a Wadati-Benioff zone reinterpretation and an orogenic model that could be
in harmony with an upward transport of mass have been searched for. The high-velocity anomalies revealed by means
of seismic tomography – regional and global – under the trench-arc zones (Van der Voo et al., 1999; Fukao et al.,
2001; Piromallo and Morelli, 2003; Spakman and Wortel, 2004; Cimini and Marchetti, 2006; among others) can be
reinterpreted as isostatically uplifted columns of denser mantle material that intrude between two decoupling plates
(Scalera, 2005, 2006b, 2006c & 2007a). The uplifting columns experience episodic phase changes toward a less
closely-packed crystal structure leading to intermediate and deep earthquakes. The concomitant cause of earthquakes
can be envisaged as rising water stored in the mantle (Lawrence and Wysession, 2006), which can produce deep
instability phenomena. The cause of the outpouring of materials involved in orogenesis should be searched for in the
increasing volume of the isostatically upwelling material and the cooperating buoyancy at the downward displaced
Clapeyron phase boundary (Figs. 4 and 5). The trenches and the backarc higher heat flow can be explained without
additional assumptions as a direct consequence of the tensional stress state and of the surfaceward transport of the
isotherms associated with the columns of uplifting mantle material. While contrasting phenomena are present in the old
framework, it is noteworthy that the new interpretation involves a simple and natural cooperation of deep natural
phenomena able to explain the surface characteristics of the trench-arc-backarc zones.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
61
Figure 1 – The data from 1800 to 1999 of the Smithsonian Institution catalogue of eruptions for the South American Region have
been used to plot the annual and triennial number of eruptions along the time axis. In a) all the non-discredited data have been
used. In b) the uncertain eruptions have been omitted. The cusps of eruptions coinciding with the occurrence of great magnitude
earthquakes are clear in both cases. In the time zone where the catalogue is incomplete – the beginning of the 19th century – only
the peak of eruption associated with the Conception event of 1835 becomes indiscernible in b). The low rate of eruptions around
1940 could be due to incomplete observations caused by the 2nd World War, but the occurrence of similar low rate periods around
1953 and 1968 is unexplained. Long periods of higher volcanic activity – e.g. 1920-1938, 1980-2000 – are also present. At the
moment no explanation of these fluctuations exists nor is it possible to envisage links with the occurrence of very deep and strong
seismic events like the 1994 Bolivia one (M=8.2; depth=641 km, data USGS).
The same correlation of great seismic events and increased rate of eruptions cannot be recognized in other Wadati-Benioff
zones. The author’s conviction is that the enhanced correlation in South America could be the consequence of an asymmetrical
expansion of the planet (Scalera and Jacob, 2003). More frequent and stronger or extreme phenomena are expected around the
Nazca region, which is the site of the maximum rate of expansion.
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 2 – a) Main earthquakes along the South American Pacific margin (M≥8.0). b) The epicentre of the 1868 earthquake and
the volcanoes that erupted in the triennium 1867-1869. c) The epicentres of the two great earthquakes of 1906 and the eruptions
that occurred in the triennium 1905-1907. d) The eruptions of the triennium 1959-1961, and the epicentre of the great Chilean
earthquake of 1960.
In addition, a unified view can be attained of marine orogenesis – namely the mid-oceanic ridges – and the continental
one. Indeed, the extension of mid-oceanic ridges into dryland fold belts (California, Tonga-Kermadec-New Zealand)
has been considered contradictory to plate tectonics because of the different state of stress (distensive versus
compressive) between them. In this framework a tentative suggestion is proposed here that the difference between the
mid-oceanic ridges (marine orogen) and the continental fold belts is probably maintained by the different rate of
rifting; the mid-oceanic ridges having a higher rifting rate which does not allow the growing volume to reach and
overcome the sea level altitude. The mid-oceanic ridges can be seen as an oceanic version of the continental fold belts;
in the oceanic ridges the folds and overthrusts are unlikely to occur due to the higher rate of rifting.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
63
Figure 3 – A 3-D plot of the entire Wadati-Benioff zone beneath the South American Pacific margin. Planar distributions of
hypocentres cannot be recognized. Clusters of hypocentres tapering downward are the typical patterns. The earthquake data
(depth ≥ 40 km) came from the Catalogue of the Relocated Hypocentres by Engdahl et al. (1998). The black circles on the
surface represent the 72 volcanoes that have erupted in historical times (data from Smithsonian Institution Catalogue). It is
possible to discern a correspondence between zones without intermediate-depth hypocentres (100 km ≤ depth ≤ 300 km) and
surface zones without active volcanoes. This fact reveals another case of a stronger than expected link between volcanism and
seismicity already highlighted in other tectonic situations (Scalera, 1997).
This model can be considered the first causal explanation – linked to deep mineralogical phases, isostasy and
expanding Earth – of at least part of an already existing more general class of orogenetic non-collisional models (Ollier
and Pain, 2000; Ollier, 2003) that derive their evidence above all from surface geology and morphology. Older
conceptions appeal to diapirical rises (Van Bemmelen, 1966 & 1978; Carey, 1976 & 1986) or to uplift of buoyant
asthenolithes (Krebs, 1975), but are at odds with the recent seismic tomographic images. The first idea on whether the
mantle-phase transformation - whether progrades or retrogrades - in the formation of depressions or uplands was
formulated by Subbotin (1970).
The proposed new interpretation is able to explain the observed non-uniformity in time of the growth of the fold belts.
Periods of enhanced growth are linked with deep mineralogical phase which – rising isostatically from depth and
having reached and overcome the appropriate lesser depth, pressure, temperature, and/or coming into the presence of
suitable fluid catalyser – can gradually transform to lighter phases. The widespread phenomenon of uplifted terraces
(Darwin, 1840 & 1897; Doglioni et al., 1994; Moretti and Guerra, 1997; Cucci, 2004; Galli and Bosi, 2004; Cucci and
Tertulliani, 2006; among others) can be related to non-uniform development of deep phase changes.
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 4 – The proposed new model of mountain building. Starting from left, a tensional situation produces a stretching of crust,
lithosphere and mantle. Due to the necessity of isostatic compensation (no more than about ten kilometres of depth can be attained
on the Earth’s surface. See e.g. Hilgenberg, 1974) the greater effect of the stretching appears as a strong uplift of the lithospheric
and mantle strata. On this uplifting column an excess of room becomes necessary because the mantle material must undergo phase
changes toward more unpacked crystal structures (Green and Ringwood, 1970; Ringwood, 1991). This surplus of increasing
volume of the decompressed material is sufficient not only to fill the space between the vertically split lithosphere and mantle, but
can also produce updoming of the crust, and subsequent relatively quick (centimetres per year) uplift. A facilitating effect in
driving the uplift is the downward displacement of the phase transition zones due to the effect of the Clapeyron curve slope (see
Figure 5). Then the created true orogen can undergo erosion, summital collapse and gravitational spreading, with final denudation
of metamorphosed crustal material previously buried by gravity nappes, together with several kinds of mantle facies. Different
rates of rifting – and evolution of the rate through geological time – can lead to different kinds of continental orogens and to midoceanic ridges.
Further phenomena that can be linked to an ascending flow are the observed greater iron content in lavas characterized
by higher temperature. This can be caused by the surfaceward transport of the isotherms associated with a deeper
provenance of the mantle material – from zones richer in this metal. Some other geochemical properties of the HIMU
and EM-1 mantle source incorporated in orogens can be explained by erosion of old continental crust instead of
recycling of ancient crust and deep-sea sediments (Gasperini et al., 2000; Hanan, 2000), in an interpretation of the
Mediterranean as a continuously nascent ocean (Scalera, 2005b). In this slowly expanding Mediterranean the
emplacement of basalts has always occurred in proximity to continental lithosphere. Obduction of ophiolites is a
further process that can find a simple explanation in this framework.
Because of the unique occurrence of a correlation between great earthquakes and increased eruption rates, South
America should be considered a high priority target of investigation. This continent is special because the occurrence
of the maximum rate of strong deep earthquakes (depth ≥ 300 km; Frohlich, 2006). The author of this paper
considers that this special status of the Nazca-South American region may be a consequence of an asymmetrical global
expansion of the planet (Scalera 2002, 2003 & 2006a), with the maximum expansion rate at the Nazca triple point
region. Obviously these researches are still in development and we need a greater amount of data and a longer period of
good observations before we can provide firmer answers to all the problems. But the scientific community should be
ready to take advantage of the opportunities offered by this special continent.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
65
Figure 5 – Two rival models of the active margins. In a) the subduction model is represented with an effect of the downward
adiabatic transport of isotherms. Because at lower temperature the phase transformation occurs at greater depth, a protuberance of
denser material over the 410 km discontinuity contributes to the so-called ‘slab pull’ force. In b) the positive anomalies in seismic
velocity underneath the trench-arc zones – revealed by tomographic methods – are interpreted as intrusions of material being
isostatically transported surfaceward. In this case the isotherms are transported toward the surface so influencing locally the depth
to which the phase transition at 400 km occurs. The effect in b) is opposite to the effect in a) and a protuberance of lower density
material is created in the denser transition zone. The buoyancy of this protuberance cooperates, together with the excess of volume
involved in phase transitions toward less-packed lattice, to the outpouring of material on the surface, namely to the orogenesis.
To understand the uniqueness of the region, to obtain geophysical information and perspective, and to increase our
knowledge of the real nature of great shallow earthquakes as well as active margins’ real geodynamics, it is strongly
recommended to install a permanent OBS and a network of geophysical instruments (Favali and Beranzoli, 2006)
along the South American Pacific margin, where extreme magnitude earthquakes and related phenomena are expected
to occur (see the recurrence of great seismic events and pulses of eruptions rate in Figure 1). There is a need for
continuous observation by satellites for ionospheric anomalies, which are possible precursors of strong earthquakes
(Pulinets and Boyarchuk, 2004; Pulinets, 2007; among vast literature), because South America is a highly
recommendable region for investigations to evaluate the reliability and limits of this new methodology, which is
similarly related to an emission-activity of the Earth. All the acquired benefits would be not only in the fields of
geosciences and civil protection, but also in other fields; this eventual endeavour would be of comparable scientific and
cultural value with respect to the ‘great physics’ enterprises, but would be achieved at a lower cost.
ACKNOWLEDGEMENTS: David Pratt’s editing largely improved English. An anonymous referee provided suggestions for
new references and additional topics to be mentioned. My thanks are offered to them.
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TABLE 1
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G. and G. Scalera (eds.), 2006: Frontiers in Earth Sciences: New Ideas and Interpretations. Annals of Geophysics, Supplement
to v. 49 (1), p. 483-500.
SCALERA, G., 2006b: The geodynamic meaning of the Wadati-Benioff earthquakes: From Apennines to a global perspective for
mountain-building. In D. Slejko and A. Rebez (eds.): Extended abstracts book of the 25th GNGTS (National Group for Solid
Earth Geophysics) annual Meeting, held in Rome 28-30 November 2006. p. 8-14.
SCALERA, G., 2006c: The geodynamic meaning of the deep earthquakes: First clues for a global perspective for fold belts? New
Concepts in Global Tectonics Newsletter, no. 41 (December), p. 45-54.
SCALERA, G., 2007a: Terremoti, trasformazioni di fase, catene a pieghe: è possibile una nuova prospettiva globale? (Earthquakes,
phase changes, fold belts: it is possible a new global perspective?) (in Italian). Rendiconti Soc. Geol. It., 4, Nuova Serie,
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
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SCALERA, G., 2007b: Geodynamics of Wadati-Benioff zone earthquakes: The 2004 Sumatra earthquake and other great
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SCALERA, G. and JACOB, K.-H. (eds.), 2003: Why Expanding Earth? A book in Honour of Ott Christoph Hilgenberg.
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2001, INGV, Rome, 465p.
SMITHSONIAN INSTITUTION, 2006: Global Volcanism Program web-site: http://www.volcano.si.edu
SPAKMAN, W. and R. WORTEL, 2004: A tomographic view on Western Mediterranean geodynamics, in “The Transmed Atlas –
The Mediterranan Region from Crust to Mantle”, edited by CAVAZZA, W., ROURE, F.M., SPAKMAN, W., STAMPFLI,
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
69
COMMENTS AND REPLIES
MORE ON ISOSTASY: QUANTITATIVE EVALUATION
Peter JAMES
Consulting Engineer
PO Box 95, Dunalley, Tasmania 7177, Australia
[email protected]
I
n the last issue (NCGT #42), the present author minimized aspects of isostasy that are widely accepted in earth science
literature: for example, the alleged uplift of a fold mountain regime in response to erosion. On the principle that one
should be able to justify the critique of any natural process by some form of analysis, based on established mechanics of
materials principles, the following is proffered.
Figure 1 provides a reasonable cross section of a fold mountain regime: elevated lands rising to, say, 8km height and deep,
low density, “roots” to just over 30 km depth. Isostasy holds that the high mountains are in equilibrium as a result of the
deep roots. That is, the mountains more or less “float”, because their low density roots are embedded in higher density
lithospheric material. Let us analyze the situation using the celebrated Arthur Holmes analogy of a series of blocks of
different heights “floating” at different depths, as shown in Figure 2.
70
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
a)
Existing Conditions
The various densities of the components of the regime are shown on the figure: essentially mountains are of lower
density 27 KN/m-3 (S.G. 2.7), embedded in a gradually increasing density profile below mean sea level, ranging from
27, through 30, to 33 KN/m-3 (S.G. 3.3). The elevated blocks rise in increments of 2 km and the roots extend down to a
maximum of 32 km depth. The hydrostatic profile is taken to be continuous across the full width of the geometry and is
neglected for simplicity.
The mass of each block above sea level, per unit distance both parallel and perpendicular to the page, gives the total
loading intensity for each block. This is arrived at by height (h) times density (γ). Uplift intensity on each block is
caused by the difference in density per unit area, between the mountain root and the density of the crustal/lithospheric
material displaced. The difference between the total load intensity and the uplift intensity is the net, or effective,
loading. The values are tabulated for the arrangement shown in Figure 2 and it can be seen that the effective loading in
all cases is well in excess of the equilibrium condition. Rather than float, the mountains apply a positive loading on the
base of the displaced lithosphere.
TABLE A
Loading Intensity Beneath Fold Mountains
Block
Total Load
Intensity
1
2
3
4
Uplift Intensity
h.γ (kPa x 104)
(2 x 103 x 27)
5.4
(4 x 103 x 27)
10.8
(6 x 103 x 27)
16.2
(8 x 103 x 27)
21.6
Nett Loading
d. Δγ (kPa x 10 )
(kPa x 104)
Nil
(8 x 103 x 10)
2,4
(8x103x3 + 12x103x 6)
9.6
(8x103x3 + 20x103x6)
14.4
5.4
4
8.4
6.6
7.2
b)
River Erosion
Let us assume a river valley is eroded into the highest block, to a depth of some 6 km with side slopes of 2 (horiz.) : 1
(vert.). Here the total loss in the mass of the block above sea level is around one third, or 7.2 x 104 kPa. The uplift
factor is unaltered and so the total loading is reduced to much the same value as the uplift, giving a nett loading of zero.
The eroded block could thus be described as existing in a state of approximate equilibrium. However, even after this
massive valley erosion, there is still no excess uplift to produce any isostatic rebound. Moreover, before isostatic
rebound can take place, the uplift would have to overcome the shear resistance along either side of the eroded block.
The vital role of shear resistance is treated below.
c)
Peneplanation
Let us take an extreme case of erosion, where the whole mountain regime is eroded down to form a peneplain at an
elevation of 2 km. The loading intensities of the individual blocks are again tabulated, as below.
TABLE B
Peneplanation of Mountain Regime
Block
1
2
3
4
Total Load (kPax104)
As before
5.4
“
“
Uplift
As before
As before
As before
As before
Nett Load (kPax104)
As before
3.0
- 4.2
- 9.0
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
71
There is now an excess of uplift pressure after peneplanation, at least for the initially more elevated blocks. But, as just
mentioned, before isostatic rebound can occur, the shear resistance along the sides of each block has to be overcome: a)
on the right hand side of Block 4; and b) by the sum of the individual drag components on the left hand sides of Blocks
2, 3 and 4. This drag is analogous to skin friction on a pile and can be taken as some proportion (>50%) of the shear
strength at the interface. Ideally, both sets of drag a) and b) should be of similar magnitude.
For this analysis, it will be clearer to use the total loadings and total uplifts for each block as a whole, taken per unit
distance perpendicular to the paper. That is, the uplift intensity of Table A is taken to act over the full basal width of
each block and the summation of uplifts for Blocks 2, 3 and 4 comes to 7 x 109 kN per unit distance perpendicular to
the page. The total loading for the same three blocks, all now at 2 km elevation, comes to 4.1 x 109 kN per unit distance
perpendicular to the page. Thus, the residual uplift for the regime as a whole is around 3 x 109 kN. For isostasy to be
mobilized, this uplift has to overcome the stepped shear resistance along the left hand sides of Blocks 2, 3 and 4 and
the full shear resistance along the right hand side of Block 4.
Average creep and/or shear strengths at the Moho have been estimated to be of the order of 1.5 – 2.0 x 105 kPa.
Taking around 60% of this for the drag component gives a value something like 1 x 105 kPa. Applied over a distance of
some 30 km along the right hand side of Block 4 indicates a drag component of 3 x 109 KN per unit distance
perpendicular to the paper. This is approximately the same magnitude as the total uplift on all three eroded blocks. The
full drag effect, when taken on both sides of the three eroded blocks thus easily exceeds the total uplift mobilized for
the system as a whole.
This simple exercise demonstrates that isostatic rebound, even under the most extreme conditions of erosion, is an
invalid mechanism. Tectonic forces (tensile and compressive, respectively) and not gravity forces are required to
produce subsidence and uplift of the crust. The origin of these tectonic forces has been explained elsewhere by the
writer (for example, The Tectonics of Geoid Change, Polar Publ., Calgary, 1994) as geoid stresses produced by large
latitude changes under polar wander. Geoid stresses are amenable to analysis and, at their maximum, are adequate to
cause tensile failure of (thin) oceanic crust and compressive failure of deep geosynclinal sediments, producing folding
and uplift by thrust faulting.
-----------------------------------------------------------------------------------------------------------------------------------------------
COMMENT
Shou, Z., 2006. Precursor of the largest earthquake of the last forty years. NCGT Newsletter, no. 41, p. 6-15.
P
age 1 of the Shou paper discusses water vapor only. Before the vapor there will be water and this should have been
discussed. When the pressure increases one or two days before the occurrence of a moderate to large earthquake
(magnitude > 6.5) the groundwater comes up in the form of fountains or springs. The vapor is from this water. The
paper mentions that the vapor is from the epicenter.
Arun BAPAT
Consulting seismologist
Pune, India
[email protected]
REPLY
I
t is logical that water existed before the vapor, but I have already discussed this. In the section entitled “Synopsis of
the Earthquake Vapor Theory”, I wrote, “Here is a brief description. When a huge rock is stressed by external forces,
its weak parts break first and small earthquakes occur. The fact that a large earthquake produces a large gap suggests
that small shocks generate small crevices, which reduce the cohesion of the rock. Next, underground water percolates
into the crevices. Its expansion, contraction, and chemistry further reduce the cohesion (1).” My papers in the
references show a table of all large earthquakes and preceding shocks within 10 km of them in Southern California
since 1981 to support the proposed crevices (2-4).
72
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Table. All big earthquakes in Southern California & preceding nearby shocks (1981~2005)
No.
1
2
3
4
5
6
7
8
9
Date
19871124
19871124
19920423
19920628
19920628
19940117
19991016
20031222
20040928
Time
UTC
1:54
13:15
4:50
11:57
15:05
12:30
9:46
19:15
17:15
Lat.
33.09
33.02
33.96
34.20
34.20
34.21
34.59
35.71
35.81
Long.
-115.79
-115.85
-116.32
-116.44
-116.83
-118.54
-116.27
-121.10
-120.38
Mag.
ML
6.2
6.6
6.1
7.3
6.3
6.7
7.1
6.5
6.0
within 10 km
within 5 km
All
Deeper All
Deeper
25
4
138
10
186
7
558
33
321
3
1602
14
166
146
520
461
141
128
345
256
9
2
79
5
250
226
430
373
12
1
37
7
44
35
90
79
Dep.
km
10.8
11.1
12.3
0.9
5.3
18.4
0.02
7.0
5.5
Note:
1. All the above data are from the new catalog of the Southern California Earthquake Data Center (SCEC) of the USGS
(http://www.data.scec.org/ftp/catalogs/SCSN/) since Feb. 20, 1981, covering the region 32~37N. Columns 8~9 and 10~11
indicate the number of shocks before and within 5 km and 10 km of an epicenter respectively.
2. Lat. = Latitude. Long. = Longitude. Mag. = Magnitude. Dep. = Depth.
3. Deeper indicates the number of preceding shocks with depths greater than or equal to those of the big earthquake. For
example, earthquake No. 1 has 138 preceding shocks within 10 km of the epicenter, of which 10 shocks have a depth
greater than or equal to the 10.8 km depth of the M6.2 hypocenter.
4. All large earthquakes have many preceding shocks around their hypocenters.
Figure 1 shows the depth distribution of the Northridge earthquake on Jan. 17, 1994 and preceding nearby shocks. Five
shocks are deeper than the Northridge hypocenter. One of them was 200 meters below the hypocenter.
Depths of shocks before & within 10 km
of the Northridge earthquake
-0.15
-0.10
-0.05
0.0
0.00
0.05
0.10
Depth (km)
-5.0
-10.0
-15.0
-20.0
-25.0
Longitude (Y=-118.54)
Hypocenter
Figure 1: Depth distribution of the Northridge earthquake and preceding nearby shocks
Notes:
1.
2.
3.
4.
5.
6.
All the above data since Feb. 20, 1981 are from the same SCEC catalog.
X-axis: Longitude. Its center is at -118.54 like that of the Northridge earthquake.
Y-axis: Depth in km.
The red square: the Northridge hypocenter at 34.21, -118.54 and 18.4 km in depth.
The yellow triangle: the small shock at 34.19, -118.54 and 18.6 km in depth on March 21, 1991.
Blue diamonds: 78 shocks within 10 km of the Northridge epicenter. Altogether, 5 shocks are deeper than the
Northridge hypocenter.
In “Earthquake Vapor, a reliable precursor” (4), I cite Cox’s excellent demonstration. On the one hand, chemical theory
and experience in the manufacture of artificial diamonds show that the formation of diamond requires a high pressure
of over 45 kilobars, which indicates a depth of over 150 kilometers and a temperature of over 1000°C in natural
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
73
conditions. On the other hand, diamond exists in river gravels. Thus, there must be a path from a depth of over 150
kilometers to the river gravels to let diamond and water pass through (5).
I would like to repeat two important pieces of evidence about the water preceding the vapor. First, the USGS
performed an experiment at the Rangely Oil Field in Western Colorado in 1969 (6), in which water was injected into
and pumped out of oil wells. Researchers found that there was a strong positive correlation between the quantity of
water injected and seismic activity. Above a threshold fluid pore pressure, seismic activity was observed to increase
dramatically. This work is supported by the results of laboratory studies of the yield strength of saturated rock. As the
rock is heated, the yield strength changes only gradually until a threshold temperature is reached. Beyond this
threshold, the rock becomes dehydrated and its yield strength drops rapidly (Fig.10 of (7)).
Since copyright prevents me from showing Fig.10 of (7), I show Figure 2 instead. After working on both the theory
and practice of earthquake prediction for 7 years, I thought that there should be a characteristic curve as in Figure 2 if
my theory was true. I drew it and showed it to a librarian for help to find such a reference and confirmed it in 1997.
The characteristic curves of various rocks looked just like that shown in Figure 2, but without the labels of “Vapor
Eruption” and “Earthquake”.
Figure 2: Dehydration
Note: I drew this figure to find reference for temperature vs. yield strength and I found it in 1997 (Fig.10 of (7)).
The above discussion shows that I did discuss the water preceding the vapor. Now, let’s turn to Bapat’s second
comment, “When the pressure increases one or two days before the occurrence of a moderate to large earthquakes
(magnitude > 6.5), the groundwater comes up in the form of fountains or springs. The vapor is from this water. The
paper mentions that the vapor is from the epicenter.” I wish his claim were true, so that evacuation would become very
easy.
On Sept. 8-10, 1996, I carried out an investigation in Yellow Stone, Wyoming, where springs erupted every day.
According to Bapat, I should have encountered a moderate earthquake at least, but I did not. Figure 3 showed a strong
erupting spring with a height of about 8-10 meters, but it did not form any earthquake cloud. Moreover, satellite images
do not show earthquake clouds there either, although springs appear every day. According to Bapat, Wyoming should
have 182 moderate earthquakes a year at least, but the USGS does not report that many. These facts seem inconsistent
with his claim.
To prove earthquake clouds from hypocenters, I will repeat two examples. First, the Bam cloud suddenly appeared
from the Bam fault at 2:00 (UTC) on Dec. 20 and stayed there continuously for 24 hours, as shown in the following
animation.
Animation of the Bam Cloud
74
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
Figure 3: Spring, photographed by me in Yellow Stone, Wyoming, USA on Sept. 10, 1996
Meteorology could not explain it, whereas at 0:58 UTC on Dec. 25, 2003 I made a public prediction of an earthquake
of magnitude 5.5 or above in Fault AB within 60 days, using the following image.
Figure 4: The Bam Cloud and the Predicted Fault AB. This infrared image (10.5-12.5 nm) is from EUMETSAT’s IODC
satellite (http://www.eumetsat.de/en/index.html), transformed and offered by Dundee University, UK
(http://www.sat.dundee.ac.uk/pdus.html ). It shows an earthquake cloud emerging from fault AB on Dec. 21, 2003, marked by a
white arrow, by which I publicly predicted an M5.5 or bigger earthquake in Fault AB within 60 days on Dec. 25, 2003
(http://quake.exit.com). On Dec. 26, an M6.8 earthquake occurred in Bam (28.99N, 58.29E), Iran (marked by *), exactly where
the cloud had emerged.
This earthquake has been the only one with a magnitude greater than or equal to 5.5 there in recorded history, so my
prediction is statistically significant. The fact that only my theory can explain this cloud and my prediction is
statistically significant demonstrates that the cloud is from the Bam hypocenter. By contrast, there was no reported
spring there and the duration from the cloud to the Bam earthquake was not 2 days.
Second, the M9 Indonesia cloud and its two partners are another good example. Three geoeruptions 1, 2 and 3
appeared suddenly at 0:00 on Nov. 15, 2004, and then developed into three long straight lines AX, BY and CZ. This
atmospheric phenomenon is rare. Neither the plate theory nor meteorology can explain why those geoeruptions
appeared locally and suddenly, why the three lines were so long (about 4,790 km each) and so straight, and what
remarkable coincidence could have generated the three large earthquakes of magnitude 6.6, 7.5 and 9 at A, B and C
respectively on Dec. 26, 2004. The whole process is shown in the following animation (1).
http://quake.exit.com/Animation/20041226King0.2.gif
The only theory to explain this high coincidence is my vapor theory, which deduces that those clouds come from
relevant hypocenters.
The above two examples are given in “Precursor of the Largest Earthquake in the Last Forty Years” (1). I wonder why
Bapat thinks those clouds come from springs less than 2 days before the earthquakes. According to my study on the
spring precursor, I found it working sometimes, but not always. Moreover, its time window is not certainly within 2
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
75
days, e.g. "Petroleum erupted about 20 meters high" from a well 11 days before the Tangshan earthquake (8). "Water
spouts erupted from as high as 115 feet above the valley floor at an estimated 400 cubic feet per second" during the
7.3 Borah Peak, Idaho earthquake on October 28, 1983 (9). I feel that he should argue that a moderate or large
earthquake has a spring within 2 days before and a spring triggers a moderate or large earthquake within 2 days after.
For readers’ interest, I suggest looking at the Turkey Geothermal Eruptions on Feb. 23, 2000 (Fig. 7 of (3)) when a
black point appeared at Point “X” at 14:00 and then tended to Point B and C where a couple of M4 earthquakes
occurred exactly at B on April 2 and another couple of M4 earthquakes occurred exactly at C on May 7. I leave it to the
readers to explain this phenomenon.
Acknowledgements
The author would like to thank Wenying Shou, Darrell Harrington, Lingyan Fang, Frank Mayhar, and Yan Fang for
their support, Dong R. Choi for inviting this note, the European Organisation for the Exploitation of Meteorological
Satellites (EUMETSAT) and Dundee University, UK, for satellite images, and the United States Geological Survey
(USGS) for earthquake data.
References:
1. Shou, Z., 2006. Precursor of the Largest Earthquake in the Last Forty Years. New Concepts in Global Tectonics 41, 6-15.
http://quake.exit.com/copies/Ncgt41.pdf
2. Shou, Z., 1999. Earthquake Clouds, a reliable precursor. Science & Utopya 64, 53~57.
http://quake.exit.com/A991003.html
3. Harrington, D., & Shou, Z., 2005. Bam Earthquake Prediction & Space Technology, SEMINARS of the United Nations
Programme on Space Applications 16, 39-63. http://quake.exit.com/copies/BamSeminars.pdf
4. Shou, Z., 2006. Earthquake Vapor, a reliable precursor. Earthquake Prediction, 21-51 (ed. Mukherjee, Saumitra. Brill
Academic Publisher, Leiden-Boston). http://quake.exit.com/copies/EQVapor.pdf
5. Cox, K. G., 1978. Kimberlite pipes. Scientific American 238, 4.
6. Bolt, B.A., 1988. Stimulation of earthquakes by water. Earthquakes, 135-139 (W.H. Freeman and Company, New York).
7. Kirby, S.H & McCormick, J.W., 1990. Inelastic properties of rocks and minerals: strength and rheology. Practical
Handbook of Physical Properties of Rocks and Minerals, 179-185 (ed. Carmichael, R.S., CRC Press, Boca Raton,
Florida).
8. Shi, H.X. & Cai, Z.H. Case examples of peculiar phenomena of subsurface fluid behavior observed in China preceding
earthquakes. Acta Seismologica Sinica 2, No. 4, 425-429 (1980).
9. Lane, T. & Waag, C. Ground-water eruptions in the Chilly Buttes area, Central Idaho. Special Publications 91, 19 (1985).
Zhonghao SHOU
Earthquake Prediction Center
500E 63rd 19K New York, NY 10021
http://quake.exit.com/
[email protected]
REPLY TO SHOU
W
hat I meant was that water comes first and then it is followed by vapor/cloud. I was trying to say that in addition
to vapor, it would be useful to study water. The explanation by Shou about water trickling through crevices,
micro cracks and micro fractures needs to be corrected. Prior to the occurrence of any moderate to large earthquake
(magnitude > 6.5) the ground water comes up in the form of a fountain or spring. This is due to increased pressure
between two moving parts of rock. The groundwater is forced up by the rise in pressure. This has been seen prior to
several earthquakes. I have two examples from Asian countries. The first is the Bhuj (Gujarat, India) earthquake, M =
7.8 on 26 January 2001 and another is Kashmir earthquake of magnitude 7.6 on 08 October 2005. A few days (up to 28
days) before the occurrence of the earthquake such fountains were seen. Shou’s remark that there should have been 182
earthquakes at Yellow Stones, Wyoming is uncalled for and could have been avoided. I have never said that the water
springs or fountains appear from any water body on the surface. The ground water is forced to come up (sometimes it
cracks the ground before appearing).
Arun BAPAT
76
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
PUBLICATIONS
INTERNATIONAL GEOLOGICAL-GEOPHYSICAL ATLAS
OF THE PACIFIC OCEAN
Boris I. VASILIEV
V.I. Il’ichev Pacific Oceanological Institute, FEB RAS, Vladivostok, Russia
[email protected]
Udintsev, G.B. [ed.], 2003. International geological-geophysical atlas of the Pacific. Scale 1:10,000,000.
Size 70 x 100 cm, full colour, 192p. Published by Intergovernmental Oceanographic Commission (IOC),
UNESCO. Moscow-St. Petersburg, Russia.
F
ollowing the decision of the Intergovernmental Oceanographic Commission (IOC), UNESCO, “International
Geological-Geophysical Atlas of the Pacific Ocean” was published in St. Petersburg in 2003. This is the third issue
of this series; the first was “Atlas of the Indian Ocean”, published in 1975, and the second was “Atlantic Ocean”,
published in 1990. The Editor-in-Chief of all three Atlases is Corresponding Member of the RAS G.B. Udintsev. A
total of 248 scientists from 10 countries, 90 of them from Russia, participated in compiling the “Atlas of the Pacific
Ocean”.
The Atlas is 70 x 100 cm in size with 192 pages of full cartographic and text information in both Russian and English
on the relief, geology and geophysics of the Pacific Ocean, its selected regions and marginal seas; it is based on the
data available as of 1st January, 2001.
The introductory section contains photos and information on the vessels that participated in studying the Pacific Ocean
and fragments of old bathymetric charts reflecting the history of mapping the Pacific floor relief. The next section
contains accounts of new technologies and geological-geophysical methods for studying the ocean, i.e. manned
underwater vehicles, navigational systems, multibeam echo sounders, side-scan sonars, reflection seismic sounding,
multichannel seismic profiling, deep seismic sounding, satellite altimetry, geothermal investigations, deep-sea drilling
and seismic tomography. The section is illustrated with photos, schemes, fragments of maps, profiles and sections
obtained using these technologies and methods.
The Atlas contains mainly 1:10,000,000 scale maps along latitude 45o in the Mercator projection, i.e. bathymetric
charts, maps of anomalous magnetic and gravity fields, those of oceanic surface depth, sedimentary cover thickness,
types of sediments, seismic maps, maps of mineral resources, etc. This set of maps is supplemented by detailed charts,
sections and tables of selected best-studied regions of the Pacific Ocean, transform faults, East Pacific Rise, Shatsky
and Obruchev Rises, deep-sea trenches, island arcs ands marginal seas. Also included are sections of the wells drilled
from the drillships “Glomar Challenger” and “JOIDES Resolution” (up to Cruise 148 inclusive). At the end of the
Atlas is a list of the materials used (800 entries).
Some review maps of the World Ocean are given as supplements. They are maps of seafloor relief based on satellite
altimetry and measured depth, gravity field maps based on satellite altimetry, maps of linear magnetic anomalies,
geodynamics of lithosphere volcanoes.
Extremely diverse geological-geophysical factual materials vividly presented in an undistorted way confirm the main
conclusions we drew earlier in the course of analyzing the Geological Map of the World (Jatskevich [ed], 2000), as
follows:
The Pacific Ocean and the surrounding foldbelts, which are still tectonically active today, represent a unique global
structure, which is often regarded as the Pacific segment of the Earth. This uniqueness is many-sided: isometric shape
of the Pacific basin, asymmetric position of the East Pacific Rise and its considerable differences from other midoceanic ridges, preferential development of active margins with a system of deep sea trenches, island arcs and marginal
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
77
seas in the west, specific geophysical characteristics of the crust and upper mantle as well as basaltoid composition
differing considerably from the composition of tholeiites from the Atlantic and Indian Oceans. Circular structure of the
Pacific belt framing the Pacific basin has its own peculiarities in metallogeny and the radial-concentric system of
megafaults.
The analysis of the materials given in the International Geological-Geophysical Atlas of the Pacific Ocean indicates
that the Pacific megabasin and the surrounding tectonic belts are the first-order global morphostructures formed during
the early stage of the Earth’s development. The crust of the Pacific megabasin is manly mafic. The megabasin formed
as the result of subsidence that started in the Jurassic and has been continuing until the present, indicating the global
process of oceanization. But it is quite possible that periodical large-amplitude elevation and subsidence here took
place in the past as well, which follows from the analysis of the paleobiogeography of surrounding continents.
The considerable difference in geological structure between the western and eastern parts of the Pacific megabain since
the Precambrian excludes the hypothetical “spreading” process postulated by plate tectonics. No factual materials
confirm the “subduction” process in deep-sea trenches. There are also no indications that the basement rocks
progressively become older from the Mid-Pacific Rise. Many other postulates of “lithosphere plates tectonics” are not
confirmed either. All of these facts testify to the complete groundlessness of this speculative theory.
The analysis of the structure of the Pacific megabasin and margins allows us to reasonably speculate about its origin
and evolution. It most probably formed about 4.5 Ga as a result of a rare cosmic event, probably related to the
appearance of the Moon-Earth system. It happened either as separation of the Moon from the ancient Earth, or in
consequence of a collision with a large planet.
It caused the specific features of the Pacific megabasin, i.e. its isometric shape, essentially mafic composition of the
crust, high tectonomagmatic activity and the presence of an isometrically-built mobile belt that had formed as a result
of crushing ancient platform margins and the subsequent polycyclic geosyncline-orogenic development.
Multiple tectonomagmatic cycles occurred in the Pacific megabasin. But the underlying ultramafic substrate produced
its “rigidity” relative to the surrounding belts. In this sense it can be regarded as a thalassocraton.
During its 4.5 Ga history, large amounts of terrigenous and volcanogenic materials had been supplied from the
surrounding continents into the Pacific megabasin. Together with the ultramafic substrate those sediments were
subjected to melting and metamorphism, which ultimately resulted in leveling the composition of the Pacific crust right
up to appearing acid rocks. The geological-geophysical materials given in the Atlas confirm this hypothesis in my
opinion.
It’s a great pity that this Atlas was published in a very small edition – only 300 copies, which cannot satisfy the
requirements of scientists worldwide. It would be advisable to republish a larger edition, supplemented by geological
maps of the Pacific Ocean and its marginal seas compiled by Jatskevich et al. in 2000 which were not included in the
first edition.
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
BOOK REVIEW
THE GREAT DINOSAUR EXTINCTION CONTROVERSY
Authors: Charles Officer and Jake Page. Addison-Wesley Publishing Company, 1996.
T
he unfortunate thing about The Great Dinosaur Extinction Controversy by Charles Officer and Jake Page
(Addison-Wesley Publishing Company, 1996) is that it must not have been read by the people who should have
read it. Immediately these two, a research professor at Dartmouth College and the founder and director of Smithsonian
books and Editorial Director of Natural History magazine, set out to determine what were the actual causes of the
dinosaur extinction at the K-T boundary. This is what they discovered:
Just as the geophysicists gave us the plate tectonic hypothesis, they also gave us the meteor impact. Walter Alvarez, a
geologist, discovered an iridium layer at Gubbio, Italy. Apparently he let his more prominent father, Luis, in on the act.
Luis was a geophysicist with many credits to his name, so he became the senior author on the 1980 paper.
At this time, a quasi-pecking order, intellectually, among scientists had been established, probably by physicists. Hold
on to your hats, folks. Mathematics and theoretical physics were on top, experimental physics just beneath. Further
down came chemistry and perhaps astronomy. Geology and paleontology were way down the list. Biology was at the
bottom. Guess who got the press? In fact, Luis Alvarez later stated in the press “I don’t like to say bad things about
paleontologists, but they’re really not very good scientists. They’re more like stamp collectors.”
Charlie and Jake did a bit of research themselves and found that the dinosaur extinction had by then already been pretty
well explained by a eustatic sealevel regression coupled with much volcanism, such as the Deccan Traps. Additionally,
most of the extinctions had already occurred.
As it turns out, the last refuge for the dinosaurs was apparently western North America; that is, from about midMissouri into the Rocky Mountains. This, despite rumors to the contrary. In South America and Asia the last dinosaurs
disappeared from the fossil record during the Campanian (83-71 Ma) and mid-Maastrichtian (71-65 Ma). In Europe
only one or two species lasted into the Maastrichtian. In North America this process began about 7 million years before
the K-T boundary; that is, about 72 Ma. The last species left around for that event were Tyrannosaurus, Triceratops,
and a few of the hadrosaurs.
Meanwhile, in the Western Interior Seaway, the mosasaurs ruled the roost, being called the tyrannosaurs of the sea.
They joined the plesiosaurs in making their exit before the end of the Cretaceous, only a few hanging around for the
fireworks.
The pterosaurs were on their way out about 40 million years before the K-T boundary. This decline is marked by the
rise of birds. The ichthyosaurs were gone about 15 million years before K-T.
According to the Alvarez faction, which unfortunately included the press and Richard Kerr, the extinction was caused
by a meteor coming to land off the Yucatan peninsula. A layer of iridium and shocked quartz were the result of this
catastrophe of firestorms, excess carbon dioxide, and soot creating a global warming.
There was a fly in the ointment, though. Geologists had long been studying the problem, having found that lowering
sealevel and excess volcanism may have been the cause of this extinction, such as it was for the dinosaurs. It’s like,
“why think if you don’t have to.” Science magazine has published, between 1980 and 1994, no less than 15 articles
tying the impact to the mass extinction. During this same time frame they only published two articles against the idea.
Not to be outdone, the British journal Nature also jumped on the bandwagon.
With such a quick start, the “silly” phase of science took over, Carl Sagan’s nuclear winter idea being the most
prominent.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
79
After having the insults heaped on them by the press and the Alvarez faction, the geologists went back out into the
field. Active volcanoes were found to produce excess iridium, exactly by the same amount as the “meteor impact.”
Then, collecting samples on both sides of Alvarez’ iridium layer produced a shock in itself, although most of us have
not heard of it because of the practicing elitist press and peer reviewers. The discovery that the iridium layer took over
400,000 years to lay down went practically unnoticed by all but the geologists. Shocked quartz grains were also
produced by volcanism.
In the 1990s someone must have realized that the idea needed a smoking gun, so a hunt for a likely crater, about 65 Ma
or so, was begun in earnest. Chicxulub off the coast of the Yucatan was selected, and everyone jumped on that
bandwagon. Once again Science and Nature were in the vanguard of publications on this subject.
Art Meyerhoff analyzed PEMEX Hole #6 years ago, a hole in the crater, and found no disturbances anywhere in the
sequence. He found that the structure “is a volcanic sequence of late Cretaceous age” and that the core contained “an
orderly sequence of Pliocene, Miocene, Oligocene, Eocene, and Paleocene sediments and then 350 m of uppermost
Cretaceous sediments with Maastrichtian microfauna above and middle Campanian fauna below, all overlying an
extensive volcanic sequence of andesite (mainly) interlayered with chiefly bentonitic breccia but also layered with Late
Cretaceous fossils.” The forces gathered against him, just by his very name it seems, and his field work was ignored
and vilified. It later turned out that another geologist took another sample and proved him right. So much for the impact
crater theory of the Alvarezes, so much for Chicxulub.
In point of fact, this book goes on to show the amount of rancor and vilifying that the entire Alvarez camp, and mostly
Luis Alvarez himself, spewed out to any and everybody. The comments made by them were uncalled for, amounting to
an absolute disgrace.
Oh, there was an extinction, but it was mainly to microscopic sea organisms and marine shellfish. The dinosaurs were
already at the end of their run. And, the extinction was caused by a drop in sealevel coupled with excessive volcanism,
such as the formation of the Deccan Traps. The disappearance of the Western Interior Seaway was also a major
problem. The exact same scenario of similar duration occurred earlier when the eruption of the Siberian Traps and a
lowering of sealevel produced the Permian extinction.
So, I now do volunteer work for the St. Louis Science Center in the Earth Sciences Department. Some of my work is in
the bone room, giving talks to groups about our large model T-rex, who happens to be in the process of eating a
triceratops. Also, the Western Interior Seaway flooded the western part of Missouri, along with our western neighbors,
such as Kansas. Many of our visitors are from Kansas, a hotbed for mosasaur fossils. Naturally, I have a lot of
questions concerning the K-T, so this book was a great help.
We have a diagram of the Chicxulub crater hanging behind the table from which I speak. I will have to deny that this
ever happened every time someone notices it.
Reviewed by: Chris SMOOT
[email protected]
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New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
NEWS
AAPG EUROPEAN CONFERENCE
18-21 November, 2007
Venue: Megaron, Athens International Conference Centre, Greece
UN-TRADITIONAL THEORIES AND IDEAS IN GLOBAL AND LARGE SCALE GEOLOGY
Co-Chairs: S. T. Tassos and K. Storetvedt
Morning, Wednesday, 21 November, 2007
8:15 -- Introductory Remarks
8:30 -- S. T. Tassos: Five Myths and One Comprehensive Proposition in Geology
8:50 -- S. T. Tassos: The Solid, Quantified, Growing and Radiating Earth
9:10 -- W. J. Sercombe, T. W. Radford: Intra-cratonic Volcanism in the Colorado Plateau and
Association with Basin and Range Rifting
9:30 -- Y. B. Galant: Three Myths
9:50 -- K. M. Storetvedt: Global Wrench Tectonics - Earth History in New Perspective
10:30 -- Break
11:00 -- P. James: On the Origin of Large Horizontal Stress Variations in the Earth's Crust
11:20 -- M. Hovland, H. Rueslåtten, C. Fichler, H. K. Johnsen: A Novel Hydrothermal Salt Theory and
its Application to Understanding Deep-Water Salt Accumulations and Piercement Structures
11:40 -- A. A. Kitchka: How Abiotic Petroleum Systems Work: Tectonically Driven Deep Fluid Sources
12:20 -- C. Hunt: Anhydride Theory, a New Theory of Petroleum and Coal Generation
Afternoon, Wednesday, 21 November, 2007
1:55 -- Introductory Remarks
2:00 -- D. R. Choi: Hydrocarbons in Deep Oceans: from a New Global Tectonic Perspective
2:20 -- G. Papadopoulos: Was the Minoan Civilization Declined Due to the Attack of the Large Tsunami
Caused by the Late Bronze Age Eruption of Thera Volcano?
2:40 -- J. Maxlow: Challenging Our Global Tectonic Myths
3:00 -- J. G. A. Croll: A New Hypothesis for Earth Lithosphere Evolution
3:20 -- D. G. Van der Meer, D. J. J. Van Hinsbergen: Permo-Triassic subducted slabs return from the
grave
3:40 -- P. Carydis: The Catalytic Importance of the Vertical Component in Earthquake Engineering
4:00 -- G. Mirkin: Radioactive Irradiation Factor of Hydrocarbon Source Rock Evaluation
Please visit http://www.aapg.org for general information, and http://aapg.confex.com/aapg/2007int/techprogram/meeting.htm or
http://www.aapg.org/athens/pdf/technicalprogramme.pdf for technical programmes. Post-congress Short course,
“Reconsideration of fundamental concepts in geology and geophysics – Practical implication”.
http://www.aapg.org/athens/course4.cfm.
*************************************
33rd IGC OSLO
6-14 August, 2008
“NEW CONCEPTS IN GLOBAL TECTONICS”
Conveners:
Dong Choi, [email protected]
Karsten Stoetvedt, [email protected]
Foese C. Wezel, [email protected]
The second circular is available at www.33igc.org. We will announce more information as it becomes available.
New Concepts in Global Tectonics Newsletter, no. 43, June, 2007
w
81
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ABOUT THE NCGT NEWSLETTER
This newsletter was initiated on the basis of discussion at the symposium “Alternative Theories to Plate Tectonics” held at the 30th
International Geological Congress in Beijing in August 1996. The name is taken from an earlier symposium held in association with
28th International Geological Congress in Washington, D. C. in 1989.
Aims include:
1. Forming an organizational focus for creative ideas not fitting readily within the scope of Plate Tectonics.
2. Forming the basis for the reproduction and publication of such work, especially where there has been censorship or
discrimination.
3. Forum for discussion of such ideas and work which has been inhibited in existing channels. This should cover a very wide scope
from such aspects as the effect of the rotation of the earth and planetary and galactic effects, major theories of development of the
earth, lineaments, interpretation of earthquake data, major times of tectonic and biological change, and so on.
4. Organization of symposia, meetings and conferences.
5. Tabulation and support in case of censorship, discrimination or victimization.