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Why did ancient civilization fall?
http://www.learner.org/interactives/collapse/
The history of humankind has been marked by patterns of growth and
decline. Some declines have been gradual, occurring over centuries.
Others have been rapid, occurring over the course of a few years. War,
drought, natural disaster, disease, overpopulation, economic disruption:
any of these or a combination of these events can bring about the
collapse of a civilization. Internal causes (such as political struggles or
overfarming) can combine with external causes (such as war or natural
disaster) to bring about a collapse. What does this mean for modern
civilizations? What can we learn from the past?
Fall of Civilization: 1.Climate change
Signs of climate change
• seasons are shifting,
• temperatures are climbing
• sea levels are rising
Impacts
•
Changing landscapes
•
Wildlife at risk
•
Rising seas
•
Increased risk of drought, fire and
floods
•
Stronger storms and increased storm
damage
•
More heat-related illness and disease
•
Economic losses
Climate Change Linked to Civilization Collapse
http://news.nationalgeographic.com/news/2001/02/0227_climate4.html
This crumbling Mayan temple, long
since abandoned, is in the Lacandón
rain forest of Guatemala. Scientists
believe that climate change might be
one of the causes leading to the
collapse of the Mayan civilization.
An article in a 1995 issue of Nature
pointed to drought as one cause of the
demise of the Maya civilization. Its
writers argued that internal factors,
including population growth and
environmental degradation, worked
with climate change and led to the
Maya collapse.
Weiss H.,and Bradley R.S., 2001. "Archaeology. What drives societal collapse?". Science 291
(5504): 609–10.
Climate Change Killed off Maya Civilization
http://news.nationalgeographic.com/news/2003/03/0313_030313_mayadrought.html
Experts say the Maya collapse could serve as a valuable lesson today
to societies in Africa and elsewhere that are vulnerable to droughts.
When droughts strike, they can trigger a chain reaction beginning with
crop failures, leading to malnutrition, increased disease and
competition for resources, and ultimately causing warfare between
nations and sociopolitical upheaval.
Harvey Weiss is an archaeologist “abrupt climate change
4,200 years before present that reduced agricultural production
in northern Mesopotamia, reduced and disrupted Akkadian
imperial revenues there, and thereby forced the Akkadian
political collapse in southern Mesopotamia Akkadian Empire”
In Mesopotamia, a canal-supported agricultural society collapsed after a
severe 200-year drought about 3,400 years ago. With wetter conditions,
civilizations thrived in the Mediterranean, Egypt, and West Asia. Ten
years after their economic peak in 2,300 B.C., however, catastrophic
droughts and cooling hurt agricultural production and caused regional
collapse.
Salinization problem
The Sumerians had a salinization
problem. Evaporating water left behind
layers of salt, and rising water tables
brought more salt to the surface.
Sumerians wrote of the earth turning
white. A solution to the problem was to
leave lands not watered for many
seasons, to let the water table fall and
let rain wash the salt down far below
the surface. But this would have taken
years. It was not done. Wheat is less
tolerant of salt than barley, and
Sumerian clay tablets describe the
Sumerian diet changing from wheat to
barley. Then the growing of barley and
other crops diminished and the
Sumerians suffered from hunger,
malnutrition and disease. A Sumer
weakened has been described as
unable to defend itself
Fall of Civilization:
2.Volcanic eruption
The volume of ejecta and the plume height of the eruption column
are probably the two most reliable criteria to use in giving an
eruption a VEI number. The VEI numbers below correspond the
the following eruption characteristics:
VEI
PLUME
HEIGHT
VOLUME
CLASSIFICATION
0
<100 m
1000s m3
Hawaiian
Kilauea
1
100-1000 m
10,000s m3
Hawaiian/Strombolia
n
Stromboli
2
1-5 km
1,000,000s m3
Strombolian/Vulcania
n
Galeras
(1992)
3
3-15 km
10,000,000 m3
Vulcanian
Ruiz (1985)
4
10-25 km
100,000,000s m3
Vulcanian/Plinian
Galunggung
(1982)
5
>25 km
1 km3
Plinian
St. Helens
(1980)
6
>25 km
10s km3
Plinian/Ultra-Plinian
Krakatau
(1883)
7
>25 km
100s km3
Ultra-Plinian
Tambora
(1815)
http://www.geology.sdsu.edu/how_volcanoes_work/Variability.html#anchor762852
EXAMPLE
The Santorini eruption (1650 BC)
The Minoan eruption of Thera, also referred
to as the Thera eruption or Santorini
eruption, was a major catastrophic volcanic
eruption (Volcanic Explosivity Index (VEI) =
6 or 7, Dense-rock equivalent (DRE) = 60
km3) which is estimated to have occurred
in the mid second millennium BC. The
eruption was one of the largest volcanic
events on Earth in recorded history. The
eruption devastated the island of Thera
(also called Santorini), including the Minoan
settlement at Akrotiri -- as well as
communities and agricultural areas on
nearby islands and on the coast of Crete. it
has been speculated that the Minoan
eruption and the destruction of the city at
Akrotiri provided the basis for or otherwise
inspired Plato's story of Atlantis.
Santorini island, Greece
Background
(http://en.wikipedia.org/wiki/Minoan_eruption)
Geological evidence shows the Thera volcano
erupted numerous times over several hundred
thousand years before the Minoan eruption. In a
repeating process, the volcano would violently
erupt, then eventually collapse into a roughly
circular seawater-filled caldera, with numerous
small islands forming the circle. The caldera
would slowly refill with magma, building a new
volcano, which erupted and then collapsed in an
ongoing cyclical process.] Another famous
volcano known to repeat a similar process is
Krakatoa in Indonesia.
Immediately prior to the Minoan eruption, the
walls of the caldera formed a nearly continuous
ring of islands with the only entrance lying
between Thera and the tiny island of Aspronisi.
This cataclysmic eruption was centered on a
small island just north of the existing island of Nea
Kameni in the centre of the then-existing caldera.
The northern part of the caldera was refilled by
the volcanic ash and lava, then collapsed again.
The Eruption
Intense magmatic activity of the first
major phase of the eruption deposited
up to 7 m (23 ft) of pumice and ash,
with a minor lithic component, southeast
and east. Archaeological evidence
indicated burial of man-made structures
with limited damage. The second and
third
eruption
phases
involved
pyroclastic flow activity and the possible
generation of tsunamis. Man-made
structures not buried during the first
phase were completely destroyed. The
third phase was also characterized by
the initiation of caldera collapse. The
fourth, and last, major phase was
marked by varied activity: lithic-rich
base surge deposits, lahars, debris
flows,
and
co-ignimbrite
ash-fall
deposits. This phase was characterized
by the completion of caldera collapse,
which produced tsunami.
The Kameni Islands formed after the caldera. Eleven eruptions since 197 B.C.
have made the two islands. The most recent eruption at Santorini was in 1950 on
Nea Kameni, the northern island. The eruption was phreatic and lasted less than
a month. It co nstructed a dome and produced lava flows.
The Tephra
On Santorini, there is a 60 m (200 ft) thick
layer of white tephra that overlies the soil
clearly delineating the ground level prior to the
eruption. This layer has three distinct bands
that indicate the different phases of the
eruption: Studies have identified four major
eruption phases, and one minor precursory
tephra fall. The thinness of the first ash layer,
along with the lack of noticeable erosion of that
layer by winter rains before the next layer was
deposited, indicate that the volcano gave the
local population a few months' warning. Since
no remains have been found at the Akrotiri site,
this preliminary volcanic activity probably
caused the island's population to flee. It is also
suggested that several months before the
eruption, Santorini experienced one or more
earthquake(s), which damaged the local
settlements. The Minoan eruption is a key
marker for the Bronze Age archaeology of the
Eastern Mediterranean world.
http://www.decadevolcano.net/s
antorini/minoaneruption.htm
Volcanology
(www.decadevolcano.net/santorini/...tion.htm)
This Plinian eruption resulted in an
estimated 30 to 35 km (19 to 22 mi) high
plume which extended into the
stratosphere. In addition, the magma
underlying the volcano came into
contact with the shallow marine
embayment, resulting in a violent steam
eruption.
The event also generated a 35 to 150 m
(115 to 490 ft) high tsunami that
devastated the north coast of Crete, 110
km (68 mi) away. The tsunami had an
impact on coastal towns such as
Amnisos, where building walls were
knocked out of alignment. On the island
of Anafi, 27 km (17 mi) to the east, ash
layers 3 m (10 ft) deep have been found,
as well as pumice layers on slopes 250
m (820 ft) above sea level.
Detail of a lpartly charred branch in the
big hole visible on the previous photo.
Preliminary results of the C-14 anaylses
confirm an age around 1700-1600 BC.
Climatic effects
Hydrogeologist Philip LaMoreaux asserted
in 1995 that the eruption caused significant
climatic
changes
in
the
eastern
Mediterranean region, Aegean Sea and
much of the Northern Hemisphere, but this
was forcefully rebutted by volcanologist
David Pyle a year later.
Around the time of the radiocarbonindicated date of the eruption, there is
evidence for a significant climatic event in
the Northern Hemisphere. The evidence
includes failure of crops in China, as well
as evidence from tree rings: bristlecone
pines of California; bog oaks of Ireland,
England, and Germany; and other trees in
Sweden. The tree rings precisely date the
event to 1628 BC.
Minoan civilization
The eruption devastated the nearby Minoan settlement at Akrotiri on Santorini, which
was entombed in a layer of pumice. It is believed that the eruption also severely affected
the Minoan population on Crete, although the extent of the impact is debated. Early
theories proposed that ashfall from Thera on the eastern half of Crete choked off plant
life, causing starvation of the local population. However, after more thorough field
examinations, this theory has lost credibility, as it has been determined that no more
than 5 mm (0.20 in) of ash fell anywhere on Crete. Other theories have been proposed
based on archeological evidence found on Crete indicating that a tsunami, likely
associated with the eruption, impacted the coastal areas of Crete and may have
severely devastated the Minoan coastal settlements. A more recent theory is that much
of the damage done to Minoan sites resulted from a large earthquake that preceded the
Thera Eruption.
Significant Minoan remains have been found above the Late Minoan I era Thera ash
layer, implying that the Thera eruption did not cause the immediate downfall of the
Minoans. As the Minoans were a sea power and depended on their naval and merchant
ships for their livelihood, the Thera eruption likely caused significant economic hardship
to the Minoans, and the loss of empire in the long run. Whether these effects were
enough to trigger the downfall of the Minoan civilization is under intense debate. The
Mycenaean conquest of the Minoans occurred in Late Minoan II period, not many years
after the eruption, and many archaeologists speculate that the eruption induced a crisis
in Minoan civilization, which allowed the Mycenaeans to conquer them easily.
Minoan ruin
Akroteri, a Minoan city on
the south part of Thera,
is
being
excavated.
About 3-6 feet (1-2 m) of
ash fell on the city which
had a population of about
30,000. The residents
appear to have been
successfully evacuated
prior to the eruption. No
bodies hav e been found
in the ash like those at
Vesuvius. Archeologists
also
reported
that
movable objects had
been taken from the city.
Santorini Eruption and the Legend of Atlantis
Plato
Solon
Atlantis
The Greek philosopher Plato (427-347 BC)
describes in his dialogs Critias and Timaeus
the disappearance of Atlantis, a circular
island populated by talented people of high
culture and wealth. Plato's account was
originally derived from Solon (640-560 BC),
the great sage and lawgiver from Athens.
While visiting the town of Sais on the Nile
delta, Solon was told by Egyptian priests of
the disappearance of a great island empire.
In the modern era, geologic and
archeological investigations hint at an
intriguing possibility -- that the demise of
Atlantis may be related to a catastrophic
Bronze Age eruption in the Aegean Sea,
which generated a flooded caldera and
destroyed an advanced Minoan civilization
living on the island group of Santorini.
Fall of Civilization: 3. Earthquake
December 26, 2003,
earthquake magnitude
6.6 hit Bam an ancient
city of Iran
Thirteen of 15 major ancient civilizations (red dots) clustered
mostly along tectonic boundaries.
http://news.sciencemag.org/sciencenow/2008/08/22-03.html
The Harappan enigma
The Harappan civilization mysteriously
disappeared in 1900 BC, after almost
2,000 years of continuous existence.
Some researchers have argued that the
civilization slowly declined because of
changing trade patterns; others, now
mostly discredited, blamed Aryan invaders
from the north. Prasad and Nur blame
earthquakes. In January 2001, a
catastrophic earthquake struck the
southern edge of the former Harappan
territory, a coastal area near the border
between India and Pakistan. In 1819, a
similar earthquake raised an 80 to 100kilometer (50 to 62 mile) ridge of earth
about 20 feet (6 meters), creating an
artificial dam known as the "Allah Bund"
(God's Dam). Both earthquakes are
evidence that the Harappan region,
though not near a traditional fault zone, is
seismically active.
Manika Prasad, a research
associate in the Rock Physics
Laboratory at Stanford, has helped
expand the study of ancient
earthquakes beyond the Eastern
Mediterranean. Together with Nur,
Prasad is studying the contribution
of earthquakes to the collapse of
the Harappan civilization in South
Asia.
(http://www.spacedaily.com/news/earth
quake-01g.html)
Evidence for Tectonic Activity During the Mature Harappan
Civilization, 2600-1800 BC.
Grijalva, K. A.; Kovach, R. L.; Nur, A. M.
American Geophysical Union, Fall Meeting 2006, abstract #T51D-1553
The mature Harappan civilization located in Pakistan and India dates from 2600
to 1800 BC. By combining seismic data, three-dimensional elastic dislocation
modeling, and archaeological findings we examined the role that earthquakes
played in the demise of Harappan settlements. …………A number of the mature
Harappan settlements are located along the dry Sarasvati-Ghaggar-Hakra river
system. The decline of these sites coincides with the divergence of the SarasvatiGhaggar-Hakra system to the Indus and Ganga river systems. A succession of
earthquakes, along with a period of aridity, likely led to the disappearance of the
Sarasvati-Ghaggar-Hakra system. ……... Along the Makran coast two
settlements, believed to have been Harappan seaports, are now located tens of
kilometers inland. ……….. Dislocation modeling demonstrates that several great
subduction earthquakes in the historical past could easily have raised the
Harappan settlements to their current inland positions above sea level. The
examples presented demonstrate that earthquakes affected the demise of
several Harappan sites either by direct shaking damage, altering the water
supply, or by changing the relative sea level.
http://adsabs.harvard.edu/abs/2006AGUFM.T51D1553G
Earthquake and stream diversion
The evidence of seismic activity in
the region, combined with the recent
discovery of an ancient riverbed at
the center of the former Harappan
region, offers a possible explanation
for the civilization's decline.
Four millennia ago, one or more
quakes could have blocked or
diverted the water that flowed
through the riverbed, say Prasad
and Nur. That would have helped
turn the part of the Harappan region
into the desert it is today -- and
destroyed the Harappan civilization
in the process.
......ประมาณ พ.ศ. 1552 อาณาจักรโยนกนาคนครใน Thailand‟s Version?
สมั ย พระเจ้ ามหาชั ย ชนะ ได้ เกิ ด น า้ ท่ ว มฉั บ พลั น
เนื่องมาจากพนังกัน้ นา้ หรื อเขื่อนเหนือนา้ พังทลายลง
จนทาให้ ที่ตงเมื
ั ้ องกลายเป็ นหนองน ้าใหญ่ เรี ยกว่าเวียง
หนองล่ ม ที่ บ้ านท่ า ข้ าวเปลื อ ก ซึ่ ง อยู่ ไ ม่ ห่ า งจาก
ทะเลสาบเชียงแสน และบริ เวณที่แม่น ้ากกต่อกับแม่น ้า
โขง ใกล้ วดั พระธาตุผาเงาและพระธาตุดอยตุง จังหวัด
เชียงราย) จนเป็ นเหตุให้ บรรดาราชวงศ์กษัตริ ย์และขุน
นางของโยนกนาคนครเสียชี วิตด้ วยเหตุนา้ ท่วมเมื อง
ทังหมด
้
พวกชาวบ้ านที่เหลือรอดชีวิตได้ ประชุมปรึกษา
กัน เลื อ กตัง้ ให้ ค นกลุ่ม หนึ่ง ที่ มิ ใ ช่ เ ชื อ้ สายราชวงศ์ ขึ น้
ดูแลพวกตน เรี ยกว่า ขุนแต่งเมือง และเรี ยกชุมชนแห่ง
นั น้ ว่ า “เ วี ย ง ป รึ ก ษ า ”เ ป็ น เ ว ลา ต่ อ ไ ป อี ก 94 ปี
อาณาจั ก รโยนกนาคนครจึ ง สิ น้ สุ ด ลงเพราะเกิ ด
แผ่นดินไหว ในสมัยพระมหาชัย.......
แคว้นโยนก: จากวิกิพีเดีย สารานุกรมเสรี
ตามตานานสิงหนวัติที่พบเป็ นเอกสารลายลักษณ์
อั ก ษรในสมั ย ล้ านนาว่ า ในยุ ค พระมหาไชยชนะ
กษัตริย์องค์สดุ ท้ ายแห่งนครโยนก ชาวเมืองทาผิดฮีต
ฮอยด้ วยการจั บ ปลาไหลเผื อ กมาสู่ กั น กิ น เวี ย ง
(นคร) จึงล่มสลายจมดินไป ในปั จจุบนั ปรากฏหนอง
น ้าขนาดใหญ่อยู่บริ เวณเขตรอยต่ออาเภอแม่จนั และ
อาเภอเชียงแสน ที่เชื่อกันว่าเคยเป็ นเวียงหนองล่มมา
แต่เก่าก่อนแหล่งน ้าแห่งนี ้น่าจะมีความสาคัญต่อการ
ด ารงชี วิ ต ของผู้ คนบนที่ ร าบเชี ย งแสน ในทาง
ธรณีวิทยาพบหลักฐานว่าบริ เวณนี ้เป็ นแนวพาดผ่าน
ของรอยเลื่อนของเปลือกโลกถึงสองแนว ซึ่งลักษณะ
เช่ น นี เ้ ป็ นสาเหตุ ใ ห้ เกิ ด แผ่ น ดิ น ไหวขึ น้ บ่ อ ยครั ง้
อนุมานได้ ว่า เหตุการณ์ ในตานานกินปลาไหลเผือก
เวี ย งล่ ม นั น้ จึ ง เป็ นการสร้ างต านานเพื่ อ อธิ บ าย
ปรากฏการณ์ทางธรรมชาติของการเกิดขึ ้นของหนอง
น ้าแห่งนี ้
Fall of Civilization:
4. Pollution
Intensive mining of mercury (Hg) began
around 1400 BC in the central Peruvian Andes.
Cinnabar (HgS or mercuric sulphide) is the
primary natural source of mercury (Hg), and
forms a bright red pigment (vermillion) when
powdered. In the Andes vermillion was used
as either a body paint or a covering on
ceremonial gold objects from the first
(Chavín) to the last (Inca) Andean empires.
Mining appears to have began before the rise of any complex or highly
stratified society (around 1400 BC). The mercury amounts peaked, however,
at about 500 BC (the height of the Chavín culture) and again about 1450 AD
(the height of the Inca culture, with Inca expansion into the central Andes). In
between, by 800 AD, there was a brief renewal in cinnabar mining. Inca
mining continued until 1564 AD when the Spanish crown assumed control
Scientists analyzed the pollution
brought about by mercury mining
in sediment cores from „lakebeds
near old mines in Huancavelica,
Peru, a city of 40,000 located
140 miles (225 kilometers)
southeast of Lima, and the
world‟s second largest mercury
deposit after Almadén, Spain.‟
An
international
team
of
researchers has looked at
mercury deposits in lakes
around Huancavelica in the
Peruvian Andes, home of the
largest deposits of mercuric ore
in the New World. Unlike studies
in the Northern hemisphere,
where there is no real evidence
of pre-industrial mining of
mercury, the team found that
Andean cinnabar mining – and
the associated mercury pollution – dated back nearly 3000 years to 1400 BC.
With the increased colonial demand for liquid mercury to use in
amalgamation to purify silver and gold, mercury levels rose massively, with a
much greater proportion being attributable to free mercury rather than
cinnabar. The smelting of the ore in the area around the mines gave rise to
high atmospheric concentrations of mercury, making it a dangerous place to
work and earning it the nickname mina de la muerte (mine of death).
Mercury residues also became much more widespread, rather than being
concentrated around Huancavelica.