The limited influence of glaciations in Tibet on global climate over the past 170 000 yr

Extensive ice cover on the Tibetan Plateau would significantly influence Earth's climate in general and the Asian monsoon system in particular, but extent and timing of Quaternary glaciations in Tibet remain highly controversial. We dated erratics on top of moraines in the climatic key areas of...

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Bibliographic Details
Published in:Earth and Planetary Science Letters
Main Authors: Schafer, JM, Tschudi, S, Zhao, ZZ, Wu, XH, Ivy-Ochs, S, Wieler, R, Baur, H, Kubik, PW, Schluchter, C
Format: Article in Journal/Newspaper
Language:English
Published: ELSEVIER SCIENCE BV 2002
Subjects:
Xizang China
exposure age
monsoons
paleoclimatology
glaciation
Geochemistry & Geophysics
EAST-ASIAN MONSOON
PRODUCTION-RATES
COSMOGENIC NUCLIDES
LAST GLACIATION
ICE-SHEET
NEON
SURFACES
PAKISTAN
STAGE-2
PLATEAU
Ice Sheet
North Atlantic
Online Access:http://ir.ieecas.cn/handle/361006/11869
https://doi.org/10.1016/S0012-821X(01)00573-8
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Summary:Extensive ice cover on the Tibetan Plateau would significantly influence Earth's climate in general and the Asian monsoon system in particular, but extent and timing of Quaternary glaciations in Tibet remain highly controversial. We dated erratics on top of moraines in the climatic key areas of Central and East Tibet using cosmogenic Be-10, Al-26, and Ne-21. Consistent exposure ages obtained by various nuclides indicate a continuous period of exposure since the deposition of the samples. Our data imply that glacial advances were restricted to a few 10 km during the last 170 kyr in Central Tibet and during the peak of the last glaciation (similar to24-13 kyr ago) in Eastern Tibet. Advances of Tibetan glaciers were much less prominent than elsewhere in the northern hemisphere most likely due to very and conditions and high sublimation rates. A proposed ice-dome covering the entire Plateau can be excluded. Thus, albedo increase of Tibet most likely did trigger neither northern hemisphere ice ages nor paleomonsoon changes during the last two glacial cycles. The glacial advance during Marine Isotope Stage 2 in East Tibet and the absence of significant glacial events during the Holocene suggest a relation of snowline lowering in East Tibet to North Atlantic cooling events rather than to periods of high precipitation by an intensified monsoon. (C) 2002 Elsevier Science B.V. All rights reserved.

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