Surface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observations
This study presents the geodetic mass balance of Kanchenjunga Glacier, one of the largest debris-covered glaciers in the easternmost Nepal Himalaya, which possesses a negative mass balance of −0.18 ± 0.17 m w.e. a −1 for the 1975–2010 study period, estimated using digital elevation models (DEMs) gen...
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Copernicus Publications
2017
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ftdoajarticles:oai:doaj.org/article:b94beca7870341d8b9cfe663488318cf 2023-05-15T18:32:29+02:00 Surface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observations D. Lamsal K. Fujita A. Sakai 2017-12-01T00:00:00Z https://doi.org/10.5194/tc-11-2815-2017 https://doaj.org/article/b94beca7870341d8b9cfe663488318cf EN eng Copernicus Publications https://www.the-cryosphere.net/11/2815/2017/tc-11-2815-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-11-2815-2017 1994-0416 1994-0424 https://doaj.org/article/b94beca7870341d8b9cfe663488318cf The Cryosphere, Vol 11, Pp 2815-2827 (2017) Environmental sciences GE1-350 Geology QE1-996.5 article 2017 ftdoajarticles https://doi.org/10.5194/tc-11-2815-2017 2022-12-31T09:23:21Z This study presents the geodetic mass balance of Kanchenjunga Glacier, one of the largest debris-covered glaciers in the easternmost Nepal Himalaya, which possesses a negative mass balance of −0.18 ± 0.17 m w.e. a −1 for the 1975–2010 study period, estimated using digital elevation models (DEMs) generated from Hexagon KH-9 and ALOS PRISM stereo images. Accurate DEMs, with a relative uncertainty of ±5.5 m, were generated from the intensive and manual editing of triangulated irregular network (TIN) models on a stereo MirrorTM/3D Monitor. The glacier ice-flow velocity field was also calculated using a feature-tracking method that was applied to two ALOS orthoimages taken in 2010. The elevation differences between the two DEMs highlight considerable surface lowering across the debris-covered area, and a slight thickening in the accumulation area of Kanchenjunga Glacier between 1975 and 2010. The magnitude and gradient of surface lowering are similar among the six glacier tributaries, even though they are situated at different elevations, which may reflect variations in the ice-flow velocity field. The pattern of surface lowering correlates well with the ice-flow velocity field over the debris-covered portion of the main tributary, suggesting that the glacier dynamics significantly affect surface lowering by altering the emergence velocity along the glacier, particularly in the compressive ablation area. Surface-lowering patterns partially correspond to the supraglacial pond area fraction of the glacier, with enhanced surface lowering observed in areas that possess a larger pond area fraction. These findings support the hypothesis that supraglacial ponds may intensify ice wastage and play a key role in the heterogeneous surface lowering of debris-covered glaciers. The estimated mass loss of Kanchenjunga Glacier is moderate compared with other debris-covered glaciers in neighboring Himalayan regions, which may be due to the lower pond area fraction of Kanchenjunga Glacier relative to other glaciers. Article in Journal/Newspaper The Cryosphere Directory of Open Access Journals: DOAJ Articles Lower Pond ENVELOPE(-57.961,-57.961,49.665,49.665) The Cryosphere 11 6 2815 2827 |
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 D. Lamsal K. Fujita A. Sakai Surface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observations |
topic_facet |
Environmental sciences GE1-350 Geology QE1-996.5 |
description |
This study presents the geodetic mass balance of Kanchenjunga Glacier, one of the largest debris-covered glaciers in the easternmost Nepal Himalaya, which possesses a negative mass balance of −0.18 ± 0.17 m w.e. a −1 for the 1975–2010 study period, estimated using digital elevation models (DEMs) generated from Hexagon KH-9 and ALOS PRISM stereo images. Accurate DEMs, with a relative uncertainty of ±5.5 m, were generated from the intensive and manual editing of triangulated irregular network (TIN) models on a stereo MirrorTM/3D Monitor. The glacier ice-flow velocity field was also calculated using a feature-tracking method that was applied to two ALOS orthoimages taken in 2010. The elevation differences between the two DEMs highlight considerable surface lowering across the debris-covered area, and a slight thickening in the accumulation area of Kanchenjunga Glacier between 1975 and 2010. The magnitude and gradient of surface lowering are similar among the six glacier tributaries, even though they are situated at different elevations, which may reflect variations in the ice-flow velocity field. The pattern of surface lowering correlates well with the ice-flow velocity field over the debris-covered portion of the main tributary, suggesting that the glacier dynamics significantly affect surface lowering by altering the emergence velocity along the glacier, particularly in the compressive ablation area. Surface-lowering patterns partially correspond to the supraglacial pond area fraction of the glacier, with enhanced surface lowering observed in areas that possess a larger pond area fraction. These findings support the hypothesis that supraglacial ponds may intensify ice wastage and play a key role in the heterogeneous surface lowering of debris-covered glaciers. The estimated mass loss of Kanchenjunga Glacier is moderate compared with other debris-covered glaciers in neighboring Himalayan regions, which may be due to the lower pond area fraction of Kanchenjunga Glacier relative to other glaciers. |
format |
Article in Journal/Newspaper |
author |
D. Lamsal K. Fujita A. Sakai |
author_facet |
D. Lamsal K. Fujita A. Sakai |
author_sort |
D. Lamsal |
title |
Surface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observations |
title_short |
Surface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observations |
title_full |
Surface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observations |
title_fullStr |
Surface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observations |
title_full_unstemmed |
Surface lowering of the debris-covered area of Kanchenjunga Glacier in the eastern Nepal Himalaya since 1975, as revealed by Hexagon KH-9 and ALOS satellite observations |
title_sort |
surface lowering of the debris-covered area of kanchenjunga glacier in the eastern nepal himalaya since 1975, as revealed by hexagon kh-9 and alos satellite observations |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/tc-11-2815-2017 https://doaj.org/article/b94beca7870341d8b9cfe663488318cf |
long_lat |
ENVELOPE(-57.961,-57.961,49.665,49.665) |
geographic |
Lower Pond |
geographic_facet |
Lower Pond |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_source |
The Cryosphere, Vol 11, Pp 2815-2827 (2017) |
op_relation |
https://www.the-cryosphere.net/11/2815/2017/tc-11-2815-2017.pdf https://doaj.org/toc/1994-0416 https://doaj.org/toc/1994-0424 doi:10.5194/tc-11-2815-2017 1994-0416 1994-0424 https://doaj.org/article/b94beca7870341d8b9cfe663488318cf |
op_doi |
https://doi.org/10.5194/tc-11-2815-2017 |
container_title |
The Cryosphere |
container_volume |
11 |
container_issue |
6 |
container_start_page |
2815 |
op_container_end_page |
2827 |
_version_ |
1766216602996441088 |