[meteorite-list] Meteor Clue To End Of Middle East Civilizations
From: FRANK B CRESSY <fcressy_at_meteoritecentral.com>
Date: Thu Apr 22 09:47:11 2004
Ran across a short note in "Archaeology" magazine, Nov/Dec 2001
(p. 31), that relates to this thread. The title is, "Rise and Fall of
Cultures: The Secret's in the Sea Salt". It correlates the fall of the
Akkadian civilization in Mesopotamia to the level of atmospheric chlorine
found preserved in Greenland ice cores. The text follows:
Among the analyses conducted on the Greenland ice cores is the tracking
of chlorine concentrations over the last 10,000 years. Winds draw chlorine
from the ocean surface in the form of NaCl (sea salt) and transport it to
Greenland where it is incorporated in the ice layers. High chlorine levels
in the cores reflect more wintry, stormy conditions --i.e., high winds
capture and carry more chlorine -- while smaller concentrations indicate
mild winters and more dominate summerlike conditions.
Joining forces with Yale archaeologist Harvy Weiss, Mayewski has used
this measurement to investigate the collapse of Akkadian imperialism in
Mesopotamia around 2200 B.C., or 4,200 years ago. The most dramatic
decrease of NaCl in the 10,000-year-long record occurred at this time.
"Looking at the Greenland record," Mayewski explains, "it turns out the
smallest amount of chlorine in out record is at 4,200 years ago, which
infers the Northern Hemisphere was experiencing extreme summerlike
conditions at this time." In desert areas like Mesopotamia -- where the year
is divided between a wet season and a dry season -- such summerlike
conditions are conducive to prolonged dry seasons, or droughts. Other
paleoclimate studies compliment the Greenland data, suggesting the people of
Mesopotamia were experiencing dramatic climate changes, such as droughts,
around the time that many major Akkadian centers were falling into disuse.
Mayewski believes the influence of the climatic event 4,200 years ago
may have reached beyond Mesopotamia. "In order for us to find an event of
that magnitude in the ice in Greenland implies this was a very big event, a
remarkable event that must have covered a large area." It's an intriguing
suggestion, the implication of which could occupy researchers throughout the
world for some time. --- End of article
A graph of the chlorine concentration (in ppb) verses time (0 to 10,000
years before present) accompanies the article. Average chlorine values over
the last 10,000 years range from 11 to 13 ppb. At 4,200 years ago chlorine
concentration abruptly fell to nearly 8 ppb.
I wonder if the possible impact in Iraq at this time might have affected
atmospheric chlorine levels described in the above article? If so, I would
have expected the atmospheric chlorine levels to increase as the impact
apparently occurred in a shallow sea which should have put salt directly
into the atmosphere. And if enough ejected "dust" were generated, cooler,
more wintry conditions should also have resulted in an increase in chlorine.
Although these thoughts seem intuitive to me, being neither an atmospheric
scientist nor an impact geologist, they could be completely wrong. Anyone
know or want to speculate how or if the impact crater and abrupt decrease in
atmospheric chlorine might be related?
At any rate, it's an interesting coincidence.
----- Original Message -----
From: Ron Baalke <baalke_at_zagami.jpl.nasa.gov>
To: Meteorite Mailing List <meteorite-list_at_meteoritecentral.com>
Sent: Monday, November 05, 2001 8:58 AM
Subject: [meteorite-list] Meteor Clue To End Of Middle East Civilizations
> Meteor clue to end of Middle East civilisations
> By Robert Matthews
> The Sunday Telegraph (United Kingdom)
> November 4, 2001
> SCIENTISTS have found the first evidence that a devastating meteor impact
> the Middle East might have triggered the mysterious collapse of
> civilisations more than 4,000 years ago.
> Studies of satellite images of southern Iraq have revealed a two-mile-wide
> circular depression which scientists say bears all the hallmarks of an
> impact crater. If confirmed, it would point to the Middle East being
> by a meteor with the violence equivalent to hundreds of nuclear bombs.
> Today's crater lies on what would have been shallow sea 4,000 years ago,
> any impact would have caused devastating fires and flooding.
> The catastrophic effect of these could explain the mystery of why so many
> early cultures went into sudden decline around 2300 BC.
> They include the demise of the Akkad culture of central Iraq, with its
> mysterious semi-mythological emperor Sargon; the end of the fifth dynasty
> Egypt's Old Kingdom, following the building of the Great Pyramids and the
> sudden disappearance of hundreds of early settlements in the Holy Land.
> Until now, archaeologists have put forward a host of separate explanations
> for these events, from local wars to environmental changes.
> Recently, some astronomers have suggested that meteor impacts could
> such historical mysteries.
> The crater's faint outline was found by Dr Sharad Master, a geologist at
> University of Witwatersrand, Johannesburg, on satellite images of the Al
> 'Amarah region, about 10 miles north-west of the confluence of the Tigris
> and Euphrates and home of the Marsh Arabs.
> "It was a purely accidental discovery," Dr Master told The Telegraph last
> week. "I was reading a magazine article about the canal-building projects
> Saddam Hussein, and there was a photograph showing lots of formations -one
> of which was very, very circular."
> Detailed analysis of other satellite images taken since the mid-1980s
> that for many years the crater contained a small lake.
> The draining of the region, as part of Saddam's campaign against the Marsh
> Arabs, has since caused the lake to recede, revealing a ring-like ridge
> inside the larger bowl-like depression - a classic feature of meteor
> The crater also appears to be, in geological terms, very recent. Dr Master
> said: "The sediments in this region are very young, so whatever caused the
> crater-like structure, it must have happened within the past 6,000 years."
> Reporting his finding in the latest issue of the journal Meteoritics &
> Planetary Science, Dr Master suggests that a recent meteor impact is the
> most plausible explanation for the structure.
> A survey of the crater itself could reveal tell-tale melted rock. "If we
> could find fragments of impact glass, we could date them using radioactive
> dating techniques," he said.
> A date of around 2300 BC for the impact may also cast new light on the
> legend of Gilgamesh, dating from the same period. The legend talks of "the
> Seven Judges of Hell", who raised their torches, lighting the land with
> flame, and a storm that turned day into night, "smashed the land
> like a cup", and flooded the area.
> The discovery of the crater has sparked great interest among scientists.
> Dr Benny Peiser, who lectures on the effects of meteor impacts at John
> Moores University, Liverpool, said it was one of the most significant
> discoveries in recent years and would corroborate research he and others
> He said that craters recently found in Argentina date from around the same
> period - suggesting that the Earth may have been hit by a shower of large
> meteors at about the same time.
Received on Thu 15 Nov 2001 03:52:53 PM PST