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Africa Is Once Again Melting
Columbus - Oct 21, 2002 A detailed analysis of six cores retrieved from the rapidly shrinking ice fields atop Tanzania's Mount Kilimanjaro shows that those tropical glaciers began to form 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. Lastly, the analysis also supports Ohio State University researchers' prediction that these unique bodies of ice will disappear in the next two decades, the victims of global warming. These findings were published today in the journal Science. Lonnie Thompson, professor of geological sciences at Ohio State and leader of an expedition in 2000 to retrieve these cores, called Kilimanjaro's ice fields "stagnant" and said they are "wasting away." Thompson and his colleagues retrieved six cores from the mountain two years ago after his team spent more than a month camped at a drill site above 19,300 feet. After a logistical nightmare requiring the hiring of 92 porters and obtaining 25 official permits, the team returned 215 meters (705 feet) of frozen ice core to the freezers at the university's Byrd Polar Research Center. One key to dating the core came with the finding of a chemical marker in the ice -- a spike of the isotope chlorine-36, a radioactive remnant of nuclear bomb testing in 1951-52. The same spike appears in cores the team had retrieved from both South America and China, and this allows them to calibrate the historic records trapped in the ice.
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