Paleo-glacial reconstruction of the Thajwas glacier in the Kashmir Himalaya using 10Be cosmogenic radionuclide dating  

作　　者：Omar Jaan Paul Shakil Ahmad Romshoo Reyaz Ahmad Dar Pankaj Kumar Soumya Prakash Dhal Sundeep Chopra 

机构地区：[1]Department of Earth Sciences,University of Kashmir,Srinagar,India [2]Islamic University of Science and Technology(IUST),Kashmir,India [3]Inter-University Accelerator Centre(IUAC),New Delhi,India [4]Department of Geoinformatics,University of Kashmir,Srinagar,India

出　　处：《Geoscience Frontiers》2022年第6期30-40,共11页地学前缘（英文版）

基　　金：conducted with the help of grants from the Department of Science and Technology (DST), Government of India under the sponsored research project titled “Centre of Excellence for Glacial Studies in Western Himalaya”;granting fellowship to Omar Jaan Paul under the project No. UFR-59313。

摘　　要：Quantitative glacial chronologies of past glaciations are sparse in the Himalaya, and mostly absent in the Kashmir Himalaya. We used cosmogenicBe exposure dating, and geomorphological mapping to reconstruct glacial advances of the Thajwas Glacier(TG) in the Great Himalayan Range of the Kashmir Himalaya. FromBe exposure dating of ten moraine boulders, four glacial stages with ages ~20.77 ±2.28 ka, ~11.46 ± 1.69 ka, ~9.12 ± 1.39 ka and ~4.19 ± 0.78 ka, were identified. The reconstructed cosmogenic radionuclide ages confirmed the global Last Glacial Maximum(g LGM), Younger Dryas, Early Holocene, and Neoglaciation episodes. As per area and volume change analyses, the TG has lost 51.1 km~2 of its area and a volume of 2.64 km~3 during the last 20.77 ± 2.28 ka. Overall, the results suggested that the TG has lost 64% of area and 73% of volume from the Last glacial maximum to Neoglaciation and about 85.74% and 87.67% of area and volume, respectively, from Neoglaciation to the present day. The equilibrium line altitude of the TG fluctuated from 4238 m a.s.l present to3365 m a.s.l during the g LGM(20.77 ± 2.28 ka). The significant cooling induced by a drop in mean ambient temperature resulted in a positive mass balance of the TG during the g LGM. Subsequently the melting accelerated due to the continuing rise of the global ambient temperature. Paleo-glacial history reconstruction of the Kashmir Himalaya, with its specific geomorphic and climatic setting, would help close the information gap about the chronology of past regional glacial episodes.

关 键 词：Glacier reconstruction Cosmogenic 10Be gLGM Kashmir Himalaya Equilibrium Line Altitude 

分 类 号：P343.6[天文地球—水文科学] P597.3[天文地球—地球物理学]