The joint driving effects of climate and weather changes caused the Chamoli glacier-rock avalanche in the high altitudes of the India Himalaya  

作　　者：Yushan ZHOU Xin LI Donghai ZHENG Zhiwei LI Baosheng AN Yingzheng WANG Decai JIANG Jianbin SU Bin CAO 

机构地区：[1]National Tibetan Plateau Data Center,State Key Laboratory of Tibetan Plateau Earth System and Resource Environment,Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China [2]School of Geosciences and Info-Physics,Central South University,Changsha 410083,China [3]College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China [4]Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China [5]University of Chinese Academy of Sciences,Beijing 100049,Chin

出　　处：《Science China Earth Sciences》2021年第11期1909-1921,共13页中国科学（地球科学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Grant Nos.41988101&42001381);the China Post-Doctoral Program for Innovative Talents(Grant No.BX20200343);the China Post-Doctoral Science Foundation(Grant No.2020M670480);The TanDEM-X data were provided as part of a science data project conducted by the German Aerospace Center(Grant No.NTI_BIST7136).

摘　　要：Ice avalanches are one of the most devastating mountain hazards,and can pose a great risk to the security of the surrounding area.Although ice avalanches have been widely observed in mountainous regions around the world,only a few ice avalanche events have been studied comprehensively,due to the lack of available data.In this study,in response to the recent catastrophic rock-ice avalanche(7 February 2021)at Chamoli in the India Himalaya,we used high-resolution satellite images and found that this event was actually a glacier-rock landslide,where the collapse of the rock-ice body was caused by the sliding of the bedrock beneath the glacier,for which the source area and volume loss were about 2.89×10^(5) m^(2) and 2.46×10^(7) m^(3),respectively,corresponding to an average elevation change of about−85 m.Furthermore,visual analysis of the dense time-series satellite images shows that the overall downward sliding of the collapsed rock-ice body initiated around the summer of 2017,and thereafter exhibited clear seasonality(mainly in summer).Meteorological analysis reveals a strong rainfall anomaly in the initiation period of the sliding and a remarkable winter warming anomaly in the 40 days before the collapse.Comparisons of multi-temporal digital elevation models(DEMs)further suggest that the glacier geometry in the collapsed areas was likely changing(i.e.,accelerated surface thinning in the lower part of the glaciers and insignificant change in the upper part),which is consistent with the region-wide climate warming.Finally,by combining the above findings and a geomorphic analysis,we conclude that the rock-ice avalanche event was mainly caused by the joint effects of climate and weather changes acting on a steeply sloping and fracture-prone geological condition.The findings of this study provide new and valuable evidence for the study of slope/glacier instability at high altitudes.This study also highlights that,for the Himalaya and other high mountain ranges,there is an urgent need to identify the glaciers that h

关 键 词：Rock-ice avalanche HIMALAYA Mountain hazards Climate change Remote sensing 

分 类 号：P467[天文地球—大气科学及气象学] P343.6