Glacier development in continental climate regions of central Asia

Jigjidsurengiin Batbaatar, Alan R. Gillespie, Michele Koppes, Douglas H. Clark, Oliver A. Chadwick, David Fink, Ari Matmon, Summer Rupper

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review

Abstract

Glaciers in central Asia that developed under a range of climatic conditions from arid to humid provide an excellent opportunity to test glacial responses to changes in climate. To do this, we mapped and dated glacial deposits at 11 sites spread over five mountain ranges in central Asia: the Altai, Tian Shan, Altyn Tagh, Qilian Shan, and Kunlun. The glacial chronologies for these sites were determined from new 10Be and 26Al exposure ages for the mapped moraines, in addition to 10Be ages available in the literature. Paleo–equilibrium-line altitudes were estimated for past glacier extents from the dated moraines. The equilibrium-line altitudes (ELAs) were also estimated for existing glaciers to characterize the spatial pattern in modern climate across the study region. Differences between the modern and paleo-ELAs (∆ELAs) were used to explore the climatic reasons for variations in the glacier sensitivities and responses to past changes in climate. The results show that the glaciers in more humid regions advanced to their maximum during marine oxygen-isotope stage (MIS) 3–2 with ∆ELAs of ~1100–600 m. However, glaciers in the arid interior of central Asia, in the rain shadows of the Karakorum and Pamir ranges and in the Gobi Desert ranges, reached their maximum between MIS 6 and 4, and glacier extents during the subsequent colder/drier MIS 3–2 were significantly smaller or did not extend beyond their cirques. Comparisons of our results and the sensitivity analysis of modern glaciers suggest that depression of air temperature was the primary driver of glacier advances in central Asia but that precipitation played a major role in shaping the spatial and temporal heterogeneity of glacier advances. Precipitation was especially important in hyperarid conditions. Therefore, inferences about paleoclimate parameters from past glacial extents must be made after careful consideration of the climatic setting in which the glaciers are found, as well as their sensitivity to climatic factors.

Original languageAmerican English
Title of host publicationSpecial Paper of the Geological Society of America
PublisherGeological Society of America
Pages123-153
Number of pages31
DOIs
StatePublished - 7 Apr 2021

Publication series

NameSpecial Paper of the Geological Society of America
Volume548

All Science Journal Classification (ASJC) codes

  • Geology

Fingerprint

Dive into the research topics of 'Glacier development in continental climate regions of central Asia'. Together they form a unique fingerprint.

Cite this