Characterizing the surge behaviour and associated ice-dammed lake evolution of the Kyagar Glacier in the Karakoram
<p>Glacier surges are prevalent in the Karakoram and occasionally threaten local residents by inundating land and initiating mass movement events. The Kyagar Glacier is well known for its surge history, and in particular its frequent blocking of the downstream valley, leading to a series of hi...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-07-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/17/2891/2023/tc-17-2891-2023.pdf |
| Summary: | <p>Glacier surges are prevalent in the Karakoram and
occasionally threaten local residents by inundating land and initiating mass
movement events. The Kyagar Glacier is well known for its surge history, and
in particular its frequent blocking of the downstream valley, leading to a
series of high-magnitude glacial lake outburst floods (GLOFs). Although the surge
dynamics of the Kyagar Glacier have been broadly described in the
literature, there remains an extensive archive of remote sensing
observations that have great potential for revealing specific surge
characteristics and their relationship with historic lake outburst floods.
In this study, we propose a new perspective on quantifying the surging
process using successive digital elevation models (DEMs), which could be
applied to other sites where glacier surges are known to occur. Advanced
Spaceborne Thermal Emission and Reflection Radiometer DEMs, High Mountain
Asia 8-meter DEMs, and the Shuttle Radar Topography Mission DEM were used to
characterize surface elevation changes throughout the period from 2000 to
2021. We also used Landsat time series imagery to quantify glacier surface
velocities and associated lake changes over the course of two surge events
between 1989 and 2021. Using these datasets, we reconstruct the surging
process of the Kyagar Glacier in unprecedented detail and find a clear signal of
surface uplift over the lower glacier tongue, along with uniformly
increasing velocities, associated with the period of surge initiation.
Seasonal variations in surface flow are still evident throughout the surge
phase, indicating the presence of water at the glacier bed. Surge activity of the
Kyagar Glacier is strongly related to the development and drainage of the
terminal ice-dammed lake, which itself is controlled by the drainage system
beneath the glacier terminus.</p> |
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| ISSN: | 1994-0416 1994-0424 |