A 25,000-year tropical climate history from bolivian ice cores
Ice cores that were recovered from the summit of Sajama mountain in Bolivia provide carbon-14-dated tropical records and extend to the Late Glacial Stage (LGS). Oxygen isotopic ratios of the ice decreased 5.4 per mil between the early Holocene and the Last Glacial Maximum, which is consistent with values from other ice cores. The abrupt onset and termination of a Younger Dryas-type event suggest atmospheric processes as the probable drivers. Regional accumulation increased during the LGS, during deglaciation, and over the past 3000 years, which is concurrent with higher water levels in regional paleolakes. Unlike polar cores, Sajama glacial ice contains eight times less dust than the Holocene ice, which reflects wetter conditions and extensive snow cover.
Thompson
LG
L. G. Thompson, M. E. Davis, K. A. Henderson, V. S. Zagorodnov, J. F. Bolzan, Byrd Polar Research Center, Department of Geological Sciences, The Ohio State University, Columbus, OH 43210, USA. E. Mosley-Thompson, Byrd Polar Research Center, D.
Davis
ME
Mosley-Thompson
E
Sowers
TA
Henderson
KA
Zagorodnov
VS
Lin
P
Mikhalenko
VN
Campen
RK
Bolzan
JF
Cole-Dai
J
Francou
B