Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, Nepal
<p>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 conte...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-06-01
|
| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/17/2305/2023/tc-17-2305-2023.pdf |
| _version_ | 1797808873332015104 |
|---|---|
| author | Y. Hu Y. Hu Y. Hu S. Harrison L. Liu L. Liu J. L. Wood |
| author_facet | Y. Hu Y. Hu Y. Hu S. Harrison L. Liu L. Liu J. L. Wood |
| author_sort | Y. Hu |
| collection | DOAJ |
| description | <p>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 <span class="inline-formula">±</span> 8 % to 74 <span class="inline-formula">±</span> 8 %, and the
water volume equivalents lie between <span class="inline-formula">1.4 ± 0.2</span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">5.9</mn><mspace width="0.125em" linebreak="nobreak"/><mo>±</mo><mspace width="0.125em" linebreak="nobreak"/><mn mathvariant="normal">0.6</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mn mathvariant="normal">6</mn></msup></mrow></math><span><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></span></span> m<span class="inline-formula"><sup>3</sup></span> 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 lacking, which is valuable for
estimating the water storage potential of rock glaciers in remote areas.</p> |
| first_indexed | 2024-03-13T06:44:08Z |
| format | Article |
| id | doaj.art-4978a463f0d144b7b29ac970635fa7fb |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-03-13T06:44:08Z |
| publishDate | 2023-06-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-4978a463f0d144b7b29ac970635fa7fb2023-06-08T10:57:16ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242023-06-01172305232110.5194/tc-17-2305-2023Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, NepalY. Hu0Y. Hu1Y. Hu2S. Harrison3L. Liu4L. Liu5J. L. Wood6Earth System Science Programme, Faculty of Science, The Chinese University of Hong Kong, Hong Kong SAR, ChinaCentre for Geography and Environmental Science, University of Exeter, Penryn, Cornwall, TR10 9FE, UKInstitute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, The Chinese University of Hong Kong, Hong Kong SAR, ChinaCentre for Geography and Environmental Science, University of Exeter, Penryn, Cornwall, TR10 9FE, UKEarth System Science Programme, Faculty of Science, The Chinese University of Hong Kong, Hong Kong SAR, ChinaInstitute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, The Chinese University of Hong Kong, Hong Kong SAR, ChinaCentre for Geography and Environmental Science, University of Exeter, Penryn, Cornwall, TR10 9FE, UK<p>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 <span class="inline-formula">±</span> 8 % to 74 <span class="inline-formula">±</span> 8 %, and the water volume equivalents lie between <span class="inline-formula">1.4 ± 0.2</span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M4" display="inline" overflow="scroll" dspmath="mathml"><mrow><mn mathvariant="normal">5.9</mn><mspace width="0.125em" linebreak="nobreak"/><mo>±</mo><mspace width="0.125em" linebreak="nobreak"/><mn mathvariant="normal">0.6</mn><mo>×</mo><msup><mn mathvariant="normal">10</mn><mn mathvariant="normal">6</mn></msup></mrow></math><span><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></span></span> m<span class="inline-formula"><sup>3</sup></span> 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 lacking, which is valuable for estimating the water storage potential of rock glaciers in remote areas.</p>https://tc.copernicus.org/articles/17/2305/2023/tc-17-2305-2023.pdf |
| spellingShingle | Y. Hu Y. Hu Y. Hu S. Harrison L. Liu L. Liu J. L. Wood Modelling rock glacier ice content based on InSAR-derived velocity, Khumbu and Lhotse valleys, Nepal The Cryosphere |
| title | 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_short | 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 |
| url | https://tc.copernicus.org/articles/17/2305/2023/tc-17-2305-2023.pdf |
| work_keys_str_mv | AT yhu modellingrockglaciericecontentbasedoninsarderivedvelocitykhumbuandlhotsevalleysnepal AT yhu modellingrockglaciericecontentbasedoninsarderivedvelocitykhumbuandlhotsevalleysnepal AT yhu modellingrockglaciericecontentbasedoninsarderivedvelocitykhumbuandlhotsevalleysnepal AT sharrison modellingrockglaciericecontentbasedoninsarderivedvelocitykhumbuandlhotsevalleysnepal AT lliu modellingrockglaciericecontentbasedoninsarderivedvelocitykhumbuandlhotsevalleysnepal AT lliu modellingrockglaciericecontentbasedoninsarderivedvelocitykhumbuandlhotsevalleysnepal AT jlwood modellingrockglaciericecontentbasedoninsarderivedvelocitykhumbuandlhotsevalleysnepal |