Progressive destabilization and triggering mechanism analysis using multiple data for Chamoli rockslide of 7 February 2021

A catastrophic rockslide occurred on 7 February 2021 in Chamoli area in the high Himalaya. In the absence of field data, multiple satellites data of decade span have been used to investigate and understand the progressive destabilization of rockslide body. A 3D geometric model was developed using ge...

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Bibliographic Details
Published in:Geomatics, Natural Hazards and Risk
Main Authors: Wenfei Mao, Lixin Wu, Ramesh P. Singh, Yuan Qi, Busheng Xie, Yingjia Liu, Yifan Ding, Zilong Zhou, Jia Li
Format: Article in Journal/Newspaper
Language:English
Published: Taylor & Francis Group 2022
Subjects:
geo
Ice
Online Access:https://doi.org/10.1080/19475705.2021.2013960
https://doaj.org/article/921a1d7a88844762a72e380f8a43483d
Description
Summary:A catastrophic rockslide occurred on 7 February 2021 in Chamoli area in the high Himalaya. In the absence of field data, multiple satellites data of decade span have been used to investigate and understand the progressive destabilization of rockslide body. A 3D geometric model was developed using geospatial information about geology, terrain, and ice cover to understand the triggering mechanism. Several causes are uncovered as: the pronounced long-term change of land surface temperature facilitated local permafrost degradation and led to ice cover shrinking since 2010; the occurrence of ice avalanche nearby in 2016 accompanying with sidewall-to-bedrock fracturing enhanced the ice segregation beneath the rockslide body; and the development of side cracks in early February 2021 led to dropping of side support and percolating of surface water. Heavy precipitation several days before favoured the destabilization, top-corner cracks developing and top-side bergschrund breaking abruptly two days before, and ice strength reduction owing air temperature rising few hours before the event triggered finally the rockslide. The frequent disasters such as cloudburst, extreme precipitation, landslides, and snow avalanches responding to global warming and climate change in the Himalayan region needs immediate attention to the chain-like geohazards and collaborative observation with satellites and other platforms.