Global Tectonics - dynamicearth.de
... tectonic processes. In addition to allowing estimates of ancient mantle geotherms, the evidence from mantle xenoliths indicates that the cool mantle roots beneath the cratons quickly reached their current thickness of ≥200 km during Archean times (Pearson et al., 2002; Carlson et al., 2005). This th ...
... tectonic processes. In addition to allowing estimates of ancient mantle geotherms, the evidence from mantle xenoliths indicates that the cool mantle roots beneath the cratons quickly reached their current thickness of ≥200 km during Archean times (Pearson et al., 2002; Carlson et al., 2005). This th ...
Plume heads, continental lithosphere, flood
... 1990). At 290 km depth and deeper the upper- The mesosphere, or transition region, is theremantle LV A does not follow the northern MAR gion of the mantle between the two rna jor seismic but is offset to the east, following the central At- discontinuities at 400 and 650 km depth. The lantic hotspots ...
... 1990). At 290 km depth and deeper the upper- The mesosphere, or transition region, is theremantle LV A does not follow the northern MAR gion of the mantle between the two rna jor seismic but is offset to the east, following the central At- discontinuities at 400 and 650 km depth. The lantic hotspots ...
Unraveling topography around subduction zones from
... zones more than anywhere else, have strong spatial gradients. At the surface of the Earth, the conjunction of these processes not only produces the most important deviations from the geoid (outlined by the 5-10 km deep trenches), but also the largest topographic slopes, offshore and onshore. The top ...
... zones more than anywhere else, have strong spatial gradients. At the surface of the Earth, the conjunction of these processes not only produces the most important deviations from the geoid (outlined by the 5-10 km deep trenches), but also the largest topographic slopes, offshore and onshore. The top ...
Ocean Observation and Research Department
... Island, JAMSTEC discovered a large seamount, comparable in size to Mt. Fuji, in the process of subduction beneath the Japanese archipelago. The knowledge obtained through these discoveries will contribute to understanding global climate change and disaster prevention associated with earthquakes in J ...
... Island, JAMSTEC discovered a large seamount, comparable in size to Mt. Fuji, in the process of subduction beneath the Japanese archipelago. The knowledge obtained through these discoveries will contribute to understanding global climate change and disaster prevention associated with earthquakes in J ...
Nitrogen isotopes in bulk marine sediment: linking seafloor
... therein; second, to use the database in order to evaluate the degree to which downcore sedimentary δ 15 N records reflect the δ 15 N of nearby core-top data, through a spatial comparison with neighbouring observations and a temporal comparison with observations throughout the Late Pleistocene. This ...
... therein; second, to use the database in order to evaluate the degree to which downcore sedimentary δ 15 N records reflect the δ 15 N of nearby core-top data, through a spatial comparison with neighbouring observations and a temporal comparison with observations throughout the Late Pleistocene. This ...
The Mg isotopic composition of Cenozoic seawater – evidence for a
... Wimpenny et al., 2010). Thus it is possible that the δ 26 Mg value of the river flux may be shifted from that expected from the Mg isotopic composition of the parent carbonate/silicate rocks. However, on long timescales we expect this effect to be minor as the average Mg isotopic offset between shale ...
... Wimpenny et al., 2010). Thus it is possible that the δ 26 Mg value of the river flux may be shifted from that expected from the Mg isotopic composition of the parent carbonate/silicate rocks. However, on long timescales we expect this effect to be minor as the average Mg isotopic offset between shale ...
A global seamount classification to aid the scientific design of
... 2.1.3. Allocation of biogeographic region Faunal composition varies throughout large areas of the worlds’ oceans, for a variety of reasons including historical as well as present day processes. This variation should be recognised before any sub-division based solely on physical factors occurs. Bioge ...
... 2.1.3. Allocation of biogeographic region Faunal composition varies throughout large areas of the worlds’ oceans, for a variety of reasons including historical as well as present day processes. This variation should be recognised before any sub-division based solely on physical factors occurs. Bioge ...
G. Heinson, Electromagnetic studies of the lithosphere and
... lithosphere lies the ductile asthenosphere, with one- to two-orders of magnitude lower viscosity. Asthenosphere represents the location in the mantle where the melting point (solidus) is most closely approached, and sometimes intersected. Seismic, gravity and isostatic observations provide constrain ...
... lithosphere lies the ductile asthenosphere, with one- to two-orders of magnitude lower viscosity. Asthenosphere represents the location in the mantle where the melting point (solidus) is most closely approached, and sometimes intersected. Seismic, gravity and isostatic observations provide constrain ...
essentials-of-oceanography-10th-edition-trujillo-test
... 36) All of the following provide evidence for continental drift except: A) age of selected continental rocks. B) apparent polar wandering. C) location of coral reef fossils. D) seafloor magnetic pattern. E) shape of continental margins. Answer: D Diff: 2 Skill: comprehension 37) Continental drift wa ...
... 36) All of the following provide evidence for continental drift except: A) age of selected continental rocks. B) apparent polar wandering. C) location of coral reef fossils. D) seafloor magnetic pattern. E) shape of continental margins. Answer: D Diff: 2 Skill: comprehension 37) Continental drift wa ...
The Patrimonial Value of the Betic Ophiolites: Rocks from the
... thicknesses of each. These reconstructions also indicate the high Ti contents of MOR ophiolites as against the low, or very low-Ti contents of the SSZ type, which is an important differen- ...
... thicknesses of each. These reconstructions also indicate the high Ti contents of MOR ophiolites as against the low, or very low-Ti contents of the SSZ type, which is an important differen- ...
seismic potential associated with subduction in the northwestern
... this low level of seismicity: (1) the North American and Juan de Fuca plates are no longer converging; (2) the plates are converging but slip is accommodated aseismically; and (3) the northwestern United States is a major seismic gap that is locked and presently seismically quiescent, but that will ...
... this low level of seismicity: (1) the North American and Juan de Fuca plates are no longer converging; (2) the plates are converging but slip is accommodated aseismically; and (3) the northwestern United States is a major seismic gap that is locked and presently seismically quiescent, but that will ...
Dynamic Earth: crustal and mantle heterogeneity
... entire globe (Debayle et al. 2005). The highest levels of 3D heterogeneity are found near the Earth’s surface and near the core – mantle boundary. More subtle features appear in the mid-mantle, including relatively narrow zones of elevated wave speed that are most likely associated with past subduct ...
... entire globe (Debayle et al. 2005). The highest levels of 3D heterogeneity are found near the Earth’s surface and near the core – mantle boundary. More subtle features appear in the mid-mantle, including relatively narrow zones of elevated wave speed that are most likely associated with past subduct ...
DETERMINATION OF RUBIDIUM IN SEAWATER
... of the calculation was about 5%. It is a significant feature of this work that each sample was measured by two entirely independent analytical techniques. The results of these measurements are given in Table 2. The flame photometric analyses and the mass spectrometric analyses agree within the estim ...
... of the calculation was about 5%. It is a significant feature of this work that each sample was measured by two entirely independent analytical techniques. The results of these measurements are given in Table 2. The flame photometric analyses and the mass spectrometric analyses agree within the estim ...
Alteration of the subducting oceanic lithosphere at the southern
... offshore of southern central Chile (43°S); here the deep-sea trench is heavily filled with up to 2 km of sediments. Seismic refraction and wide-angle data, complemented by seismic reflection imaging of sediments, are used to derive a two-dimensional velocity model using joint refraction and reflect ...
... offshore of southern central Chile (43°S); here the deep-sea trench is heavily filled with up to 2 km of sediments. Seismic refraction and wide-angle data, complemented by seismic reflection imaging of sediments, are used to derive a two-dimensional velocity model using joint refraction and reflect ...
SeiSmological grand challengeS in UnderStanding earth`S
... Seismologists “keep their ear” on Earth’s internal systems, listening for signals arising from both natural and human-made energy sources distributed around the globe. These seismic signals contain a wealth of information that enables seismologists to quantify active wave sources and determine struc ...
... Seismologists “keep their ear” on Earth’s internal systems, listening for signals arising from both natural and human-made energy sources distributed around the globe. These seismic signals contain a wealth of information that enables seismologists to quantify active wave sources and determine struc ...
Palaeogeography, Palaeoclimatology, Palaeoecology
... data obtained from stratigraphic sections in the Yangtze Gorges area that, according to recent paleogeographic reconstruction, were deposited in a restricted intrashelf lagoon. In order to test the redox conditions in open-ocean, deep-water environments, we have conducted a detailed morphological an ...
... data obtained from stratigraphic sections in the Yangtze Gorges area that, according to recent paleogeographic reconstruction, were deposited in a restricted intrashelf lagoon. In order to test the redox conditions in open-ocean, deep-water environments, we have conducted a detailed morphological an ...
Chapter 2 The Way the Earth Works: Plate Tectonics
... night recording wind speeds and temperatures on Greenland’s polar plateau. At the time, Wegener was well known, not only to researchers studying climate but also to geologists. Some fifteen years earlier, he had published a small book, The Origin of the Continents and Oceans, in which he had dared t ...
... night recording wind speeds and temperatures on Greenland’s polar plateau. At the time, Wegener was well known, not only to researchers studying climate but also to geologists. Some fifteen years earlier, he had published a small book, The Origin of the Continents and Oceans, in which he had dared t ...
Buildup of a dynamically supported orogenic plateau: Numerical
... Abstract The Iranian plateau is a vast inland region with a smooth average elevation of c. 1.5 km formed at the rear of the Zagros orogen as a result of the Arabia-Eurasia collision (i.e., over the last 30–35 Myr). This collision zone is of particular interest due to its disputed resemblance to the ...
... Abstract The Iranian plateau is a vast inland region with a smooth average elevation of c. 1.5 km formed at the rear of the Zagros orogen as a result of the Arabia-Eurasia collision (i.e., over the last 30–35 Myr). This collision zone is of particular interest due to its disputed resemblance to the ...
Attachment between brittle and ductile crust at wrenching
... question about strike-slip systems is the nature of deformation below these rigid blocks. This issue was well laid out by Sylvester’s (1988) discussion of mechanical stratigraphy in wrench zones. The details of deformation in the zone below the rigid blocks depends on whether the system is driven fr ...
... question about strike-slip systems is the nature of deformation below these rigid blocks. This issue was well laid out by Sylvester’s (1988) discussion of mechanical stratigraphy in wrench zones. The details of deformation in the zone below the rigid blocks depends on whether the system is driven fr ...
Iodine chemistry reflects productivity and denitrification in the
... Intermonsoon of 1995. Two separate regimes of iodine chemistry are highlighted in this study: (1) the well-oxygenated surface layer (WOSL) where iodide concentrations were in the range of 158–558 nM, and (2) the oxygen minimum zone (OMZ) where total iodine concentrations [primarily as iodide and in ...
... Intermonsoon of 1995. Two separate regimes of iodine chemistry are highlighted in this study: (1) the well-oxygenated surface layer (WOSL) where iodide concentrations were in the range of 158–558 nM, and (2) the oxygen minimum zone (OMZ) where total iodine concentrations [primarily as iodide and in ...
Whole-mantle convection with tectonic plates preserves
... models embedded with the latest geological paleo-tectonic reconstructions and ground-truthed with new Hf-Nd isotope data, suggest that uppermost mantle at one location (e.g. under Indian Ocean) circulates down to the core-mantle boundary (CMB), but returns within ≥100 Myrs via large-scale convection ...
... models embedded with the latest geological paleo-tectonic reconstructions and ground-truthed with new Hf-Nd isotope data, suggest that uppermost mantle at one location (e.g. under Indian Ocean) circulates down to the core-mantle boundary (CMB), but returns within ≥100 Myrs via large-scale convection ...
Initiation of Subduction Zones as a Consequence
... respect to the asthenosphere. Therefore, it would be physically optimal if one part of the lithosphere experienced a greater gravitational attraction than its adjacent neighbour before or during the initiation of a subduction zone. This requires the pre-existence of a density contrast within the lit ...
... respect to the asthenosphere. Therefore, it would be physically optimal if one part of the lithosphere experienced a greater gravitational attraction than its adjacent neighbour before or during the initiation of a subduction zone. This requires the pre-existence of a density contrast within the lit ...
Report of the ICES GOOS Steering Group (IGSG)
... and ocean energy. Thus, there are many potential areas of cooperation with ICES and scientists active in ICES are also active in the RAs. It is important to realize that although these are U.S. funded activities, Canadian investigators and institutions are involved in NERACOOS. Other of the IOOS RA’ ...
... and ocean energy. Thus, there are many potential areas of cooperation with ICES and scientists active in ICES are also active in the RAs. It is important to realize that although these are U.S. funded activities, Canadian investigators and institutions are involved in NERACOOS. Other of the IOOS RA’ ...
Earth Planet. Sci. Lett., 139, 1-16, 1996.
... [22,23]), the first-order conclusion is that there is a regional depth anomaly which is independent of the effects of overlapping hot-spots, thickened crust and sedimentary aprons. This hypothesis is critically dependent upon the quality of the bathymetric data acquired over the young seafloor just ...
... [22,23]), the first-order conclusion is that there is a regional depth anomaly which is independent of the effects of overlapping hot-spots, thickened crust and sedimentary aprons. This hypothesis is critically dependent upon the quality of the bathymetric data acquired over the young seafloor just ...
Tsunami Detection and Warnings for the United States
... earthquake and massive landslides off the coast of southwest Alaska caused a disastrous tsunami for the Hawaiian Islands only hours later. Other NOAA Supporting Technologies. As early as the 108th Congress, legislation was introduced to adapt technologies that might contribute to part of an enhanced ...
... earthquake and massive landslides off the coast of southwest Alaska caused a disastrous tsunami for the Hawaiian Islands only hours later. Other NOAA Supporting Technologies. As early as the 108th Congress, legislation was introduced to adapt technologies that might contribute to part of an enhanced ...
Ocean
An ocean (from Ancient Greek Ὠκεανός, transc. Okeanós, the sea of classical antiquity) is a body of saline water that composes much of a planet's hydrosphere. On Earth, an ocean is one of the major conventional divisions of the World Ocean, which covers almost 71% of its surface. These are, in descending order by area, the Pacific, Atlantic, Indian, Southern, and Arctic Oceans. The word sea is often used interchangeably with ""ocean"" in American English but, strictly speaking, a sea is a body of saline water (generally a division of the world ocean) partly or fully enclosed by land.Saline water covers approximately 72% of the planet's surface (~3.6×108 km2) and is customarily divided into several principal oceans and smaller seas, with the ocean covering approximately 71% of Earth's surface. The ocean contains 97% of Earth's water, and oceanographers have stated that only 5% of the World Ocean has been explored. The total volume is approximately 1.35 billion cubic kilometers (320 million cu mi) with an average depth of nearly 3,700 meters (12,100 ft).As it is the principal component of Earth's hydrosphere, the world ocean is integral to all known life, forms part of the carbon cycle, and influences climate and weather patterns. It is the habitat of 230,000 known species, although much of the oceans depths remain unexplored, and over two million marine species are estimated to exist. The origin of Earth's oceans remains unknown; oceans are thought to have formed in the Hadean period and may have been the impetus for the emergence of life.Extraterrestrial oceans may be composed of water or other elements and compounds. The only confirmed large stable bodies of extraterrestrial surface liquids are the lakes of Titan, although there is evidence for the existence of oceans elsewhere in the Solar System. Early in their geologic histories, Mars and Venus are theorized to have had large water oceans. The Mars ocean hypothesis suggests that nearly a third of the surface of Mars was once covered by water, and a runaway greenhouse effect may have boiled away the global ocean of Venus. Compounds such as salts and ammonia dissolved in water lower its freezing point, so that water might exist in large quantities in extraterrestrial environments as brine or convecting ice. Unconfirmed oceans are speculated beneath the surface of many dwarf planets and natural satellites; notably, the ocean of Europa is estimated to have over twice the water volume of Earth. The Solar System's giant planets are also thought to have liquid atmospheric layers of yet to be confirmed compositions. Oceans may also exist on exoplanets and exomoons, including surface oceans of liquid water within a circumstellar habitable zone. Ocean planets are a hypothetical type of planet with a surface completely covered with liquid.