Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, Nepal
Active rock glaciers are viscous flow features embodying ice-rich permafrost and other ice masses. They contain significant amounts of ground ice and serve as potential freshwater reservoirs as mountain glaciers melt in response to climate warming. However, current knowledge about ice content in roc...
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ftcopernicus:oai:publications.copernicus.org:tc93897 2023-07-02T03:29:26+02:00 Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, Nepal Hu, Yan Harrison, Stephan Liu, Lin Wood, Joanne Laura 2023-06-08 application/pdf https://doi.org/10.5194/tc-17-2305-2023 https://tc.copernicus.org/articles/17/2305/2023/ eng eng doi:10.5194/tc-17-2305-2023 https://tc.copernicus.org/articles/17/2305/2023/ eISSN: 1994-0424 Text 2023 ftcopernicus https://doi.org/10.5194/tc-17-2305-2023 2023-06-12T16:24:16Z Active rock glaciers are viscous flow features embodying ice-rich permafrost and other ice masses. They contain significant amounts of ground ice and serve as potential freshwater reservoirs as mountain glaciers melt in response to climate warming. However, current knowledge about ice content in rock glaciers has been acquired mainly from in situ investigations in limited study areas, which hinders a comprehensive understanding of ice storage in rock glaciers situated in remote mountains over local to regional scales. This study proposes a novel approach for assessing the hydrological value of rock glaciers in a more quantitative way and presents exploratory results focusing on a small region. We develop an empirical rheological model to infer ice content of rock glaciers using readily available input data, including rock glacier planar shape, surface slope angle, active layer thickness, and surface velocity. The model is calibrated and validated using observational data from the Chilean Andes and the Swiss Alps. We apply the model to five rock glaciers in the Khumbu and Lhotse valleys, northeastern Nepal. The velocity constraints applied to the model are derived from interferometric synthetic aperture radar (InSAR) measurements. The volume of rock glacier is estimated based on an existing scaling approach. The inferred volumetric ice fraction in the Khumbu and Lhotse valleys ranges from 70 ± 8 % to 74 ± 8 %, and the water volume equivalents lie between 1.4 ± 0.2 and 5.9 ± 0.6 × 10 6 <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="75pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="72c379179c7952689646417d01738b54"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-17-2305-2023-ie00001.svg" width="75pt" height="14pt" src="tc-17-2305-2023-ie00001.png"/></svg:svg> m 3 for the coherently moving parts of individual rock glaciers. Due to the accessibility of the model inputs, our approach is applicable to permafrost regions where observational data are ... Text Active layer thickness Ice permafrost Copernicus Publications: E-Journals The Cryosphere 17 6 2305 2321 |
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Open Polar |
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Copernicus Publications: E-Journals |
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ftcopernicus |
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English |
description |
Active rock glaciers are viscous flow features embodying ice-rich permafrost and other ice masses. They contain significant amounts of ground ice and serve as potential freshwater reservoirs as mountain glaciers melt in response to climate warming. However, current knowledge about ice content in rock glaciers has been acquired mainly from in situ investigations in limited study areas, which hinders a comprehensive understanding of ice storage in rock glaciers situated in remote mountains over local to regional scales. This study proposes a novel approach for assessing the hydrological value of rock glaciers in a more quantitative way and presents exploratory results focusing on a small region. We develop an empirical rheological model to infer ice content of rock glaciers using readily available input data, including rock glacier planar shape, surface slope angle, active layer thickness, and surface velocity. The model is calibrated and validated using observational data from the Chilean Andes and the Swiss Alps. We apply the model to five rock glaciers in the Khumbu and Lhotse valleys, northeastern Nepal. The velocity constraints applied to the model are derived from interferometric synthetic aperture radar (InSAR) measurements. The volume of rock glacier is estimated based on an existing scaling approach. The inferred volumetric ice fraction in the Khumbu and Lhotse valleys ranges from 70 ± 8 % to 74 ± 8 %, and the water volume equivalents lie between 1.4 ± 0.2 and 5.9 ± 0.6 × 10 6 <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="75pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="72c379179c7952689646417d01738b54"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-17-2305-2023-ie00001.svg" width="75pt" height="14pt" src="tc-17-2305-2023-ie00001.png"/></svg:svg> m 3 for the coherently moving parts of individual rock glaciers. Due to the accessibility of the model inputs, our approach is applicable to permafrost regions where observational data are ... |
format |
Text |
author |
Hu, Yan Harrison, Stephan Liu, Lin Wood, Joanne Laura |
spellingShingle |
Hu, Yan Harrison, Stephan Liu, Lin Wood, Joanne Laura Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, Nepal |
author_facet |
Hu, Yan Harrison, Stephan Liu, Lin Wood, Joanne Laura |
author_sort |
Hu, Yan |
title |
Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, Nepal |
title_short |
Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, Nepal |
title_full |
Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, Nepal |
title_fullStr |
Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, Nepal |
title_full_unstemmed |
Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, Nepal |
title_sort |
modelling rock glacier ice content based on insar-derived velocity, khumbu and lhotse valleys, nepal |
publishDate |
2023 |
url |
https://doi.org/10.5194/tc-17-2305-2023 https://tc.copernicus.org/articles/17/2305/2023/ |
genre |
Active layer thickness Ice permafrost |
genre_facet |
Active layer thickness Ice permafrost |
op_source |
eISSN: 1994-0424 |
op_relation |
doi:10.5194/tc-17-2305-2023 https://tc.copernicus.org/articles/17/2305/2023/ |
op_doi |
https://doi.org/10.5194/tc-17-2305-2023 |
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The Cryosphere |
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17 |
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6 |
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2305 |
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2321 |
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1770274322102878208 |