摘要：This study presents results from a glacier-climate
model that reconstructed glacio-climatological
conditions during the last local glaciation maximum (LLGM) in the Cordillera to the north of
Cochabamba (17°15'S, 66°15'W), Bolivia. Results
emphasize the temperature-sensitivity of glaciers on
the eastern slope of the Cordillera Oriental. Maximum glacier advances appear to have been caused
by a massive cooling of about 6.5°C while annual
preeipitation was about 300 mm higher than today
(850 mm/yr). Modeling results indicate maximum
glacial advances during cold phases such as MIS 2
(25–18 kyr B.P.) and minor advances during late glacial cool events (12–10 kyr B.P.). This chronology is
supported by exposure age dating results. Further
evidence may be found in the low AAR-values (accumulation area ratio) which indicate low mass balance
gradients and therefore cold climate conditions. Modeled basal shear stresses smaller than 1 bar exelude
extremely «cold-dry» or «warm-wet» conditions. The
spatial pattern of regional paleo-ELA's (equilibrium
line altitude). with higher ELAs in the western part
of the study area, reflects a strong east-west gradient
in paleoprecipitation. Easterly summer preeipitation
is suggested to be the reason for this phenomenon.
These results are in agreement with other studies of
the east-Andean slope, indicating temperature as the
driving factor for maximum glacier advances in northwestern
Argentina.
