Posted: Thu Dec 20, 2007 3:50 pm
http://researchnews.osu.edu/archive/kilicores.htm
“AFRICAN ICE CORE ANALYSIS REVEALS CATASTROPHIC DROUGHTS, SHRINKING ICE FIELDS AND CIVILIZATION SHIFTS
COLUMBUS, Ohio – A detailed analysis of six cores retrieved from the rapidly shrinking ice fields atop Tanzania’s Mount Kilimanjaro shows that those tropical glaciers began forming about 11,700 years ago.
The cores also yielded remarkable evidence of three catastrophic droughts that plagued the tropics 8,300, 5,200 and 4,000 years ago.
…
The cores showed an abrupt depletion in oxygen-18 isotopes that researchers believe signals a second drought event occurring around 5,200 years ago. This coincides with the period when anthropologists believe people in the region began to come together to form cities and social structures. Prior to this, the population of mainly hunters and gatherers had been more scattered.
The third marker is a visible dust layer in the ice cores dating back to about 4,000 years ago. Thompson believes this marks a severe 300-year drought which struck the region. Historical records show that a massive drought rocked the Egyptian empire at the time and threatened the rule of the Pharaohs. Until this time, Thompson said, people had been able to survive in areas that are now just barren Sahara Desert.
…”
The dates don’t quite jibe. It would be nice to know what margins of error for the various dates are.
“AFRICAN ICE CORE ANALYSIS REVEALS CATASTROPHIC DROUGHTS, SHRINKING ICE FIELDS AND CIVILIZATION SHIFTS
COLUMBUS, Ohio – A detailed analysis of six cores retrieved from the rapidly shrinking ice fields atop Tanzania’s Mount Kilimanjaro shows that those tropical glaciers began forming about 11,700 years ago.
The cores also yielded remarkable evidence of three catastrophic droughts that plagued the tropics 8,300, 5,200 and 4,000 years ago.
…
The cores showed an abrupt depletion in oxygen-18 isotopes that researchers believe signals a second drought event occurring around 5,200 years ago. This coincides with the period when anthropologists believe people in the region began to come together to form cities and social structures. Prior to this, the population of mainly hunters and gatherers had been more scattered.
The third marker is a visible dust layer in the ice cores dating back to about 4,000 years ago. Thompson believes this marks a severe 300-year drought which struck the region. Historical records show that a massive drought rocked the Egyptian empire at the time and threatened the rule of the Pharaohs. Until this time, Thompson said, people had been able to survive in areas that are now just barren Sahara Desert.
…”
The dates don’t quite jibe. It would be nice to know what margins of error for the various dates are.