Climatic control on seasonal variations in mountain glacier surface velocity
Accurate measurements of ice flow are essential to predict future changes in glaciers and ice caps. Glacier displacement can in principle be measured on the large scale by cross-correlation of satellite images. At weekly to monthly scales, the expected displacement is often of the same order as the...
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2023
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ftdoajarticles:oai:doaj.org/article:002f7cbb81c447308375765080b4c0f3 2023-06-06T11:59:53+02:00 Climatic control on seasonal variations in mountain glacier surface velocity U. Nanni D. Scherler F. Ayoub R. Millan F. Herman J.-P. Avouac 2023-04-01T00:00:00Z https://doi.org/10.5194/tc-17-1567-2023 https://doaj.org/article/002f7cbb81c447308375765080b4c0f3 EN eng Copernicus Publications https://tc.copernicus.org/articles/17/1567/2023/tc-17-1567-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-1567-2023 1994-0416 1994-0424 https://doaj.org/article/002f7cbb81c447308375765080b4c0f3 The Cryosphere, Vol 17, Pp 1567-1583 (2023) Environmental sciences GE1-350 Geology QE1-996.5 article 2023 ftdoajarticles https://doi.org/10.5194/tc-17-1567-2023 2023-04-16T00:37:47Z Accurate measurements of ice flow are essential to predict future changes in glaciers and ice caps. Glacier displacement can in principle be measured on the large scale by cross-correlation of satellite images. At weekly to monthly scales, the expected displacement is often of the same order as the noise for the commonly used satellite images, complicating the retrieval of accurate glacier velocity. Assessments of velocity changes on short timescales and over complex areas such as mountain ranges are therefore still lacking but are essential to better understand how glacier dynamics are driven by internal and external factors. In this study, we take advantage of the wide availability and redundancy of satellite imagery over the western Pamirs to retrieve glacier velocity changes over 10 d intervals for 7 years and for a wide range of glacier geometry and dynamics. Our results reveal strong seasonal trends. In spring/summer, we observe velocity increases of up to 300 % compared to a slow winter period. These accelerations clearly migrate upglacier throughout the melt season, which we link to changes in subglacial hydrology efficiency. In autumn, we observe glacier accelerations that have rarely been observed before. These episodes are primarily confined to the upper ablation zone with a clear downglacier migration. We suggest that they result from glacier instabilities caused by sudden subglacial pressurization in response to (1) supraglacial pond drainage and/or (2) gradual closure of the hydrological system. Our 10 d resolved measurements allow us to characterize the short-term response of glaciers to changing meteorological and climatic conditions. Article in Journal/Newspaper The Cryosphere Directory of Open Access Journals: DOAJ Articles The Cryosphere 17 4 1567 1583 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental sciences GE1-350 Geology QE1-996.5 |
spellingShingle |
Environmental sciences GE1-350 Geology QE1-996.5 U. Nanni D. Scherler F. Ayoub R. Millan F. Herman J.-P. Avouac Climatic control on seasonal variations in mountain glacier surface velocity |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
Accurate measurements of ice flow are essential to predict future changes in glaciers and ice caps. Glacier displacement can in principle be measured on the large scale by cross-correlation of satellite images. At weekly to monthly scales, the expected displacement is often of the same order as the noise for the commonly used satellite images, complicating the retrieval of accurate glacier velocity. Assessments of velocity changes on short timescales and over complex areas such as mountain ranges are therefore still lacking but are essential to better understand how glacier dynamics are driven by internal and external factors. In this study, we take advantage of the wide availability and redundancy of satellite imagery over the western Pamirs to retrieve glacier velocity changes over 10 d intervals for 7 years and for a wide range of glacier geometry and dynamics. Our results reveal strong seasonal trends. In spring/summer, we observe velocity increases of up to 300 % compared to a slow winter period. These accelerations clearly migrate upglacier throughout the melt season, which we link to changes in subglacial hydrology efficiency. In autumn, we observe glacier accelerations that have rarely been observed before. These episodes are primarily confined to the upper ablation zone with a clear downglacier migration. We suggest that they result from glacier instabilities caused by sudden subglacial pressurization in response to (1) supraglacial pond drainage and/or (2) gradual closure of the hydrological system. Our 10 d resolved measurements allow us to characterize the short-term response of glaciers to changing meteorological and climatic conditions. |
format |
Article in Journal/Newspaper |
author |
U. Nanni D. Scherler F. Ayoub R. Millan F. Herman J.-P. Avouac |
author_facet |
U. Nanni D. Scherler F. Ayoub R. Millan F. Herman J.-P. Avouac |
author_sort |
U. Nanni |
title |
Climatic control on seasonal variations in mountain glacier surface velocity |
title_short |
Climatic control on seasonal variations in mountain glacier surface velocity |
title_full |
Climatic control on seasonal variations in mountain glacier surface velocity |
title_fullStr |
Climatic control on seasonal variations in mountain glacier surface velocity |
title_full_unstemmed |
Climatic control on seasonal variations in mountain glacier surface velocity |
title_sort |
climatic control on seasonal variations in mountain glacier surface velocity |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-1567-2023 https://doaj.org/article/002f7cbb81c447308375765080b4c0f3 |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 17, Pp 1567-1583 (2023) |
op_relation |
https://tc.copernicus.org/articles/17/1567/2023/tc-17-1567-2023.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-17-1567-2023 1994-0416 1994-0424 https://doaj.org/article/002f7cbb81c447308375765080b4c0f3 |
op_doi |
https://doi.org/10.5194/tc-17-1567-2023 |
container_title |
The Cryosphere |
container_volume |
17 |
container_issue |
4 |
container_start_page |
1567 |
op_container_end_page |
1583 |
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