Supra‐glacial deposition and flux of catastrophic rock–slope failure debris, south‐central Alaska
ABSTRACT The ongoing debate over the effects of global environmental change on Earth's cryosphere calls for detailed knowledge about process rates and their variability in cold environments. In this context, appraisals of the coupling between glacier dynamics and para‐glacial erosion rates in t...
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crwiley:10.1002/esp.3311 2024-06-02T08:07:01+00:00 Supra‐glacial deposition and flux of catastrophic rock–slope failure debris, south‐central Alaska Uhlmann, Manuela Korup, Oliver Huggel, Christian Fischer, Luzia Kargel, Jeffrey S. 2012 http://dx.doi.org/10.1002/esp.3311 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.3311 https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.3311 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Earth Surface Processes and Landforms volume 38, issue 7, page 675-682 ISSN 0197-9337 1096-9837 journal-article 2012 crwiley https://doi.org/10.1002/esp.3311 2024-05-03T11:11:17Z ABSTRACT The ongoing debate over the effects of global environmental change on Earth's cryosphere calls for detailed knowledge about process rates and their variability in cold environments. In this context, appraisals of the coupling between glacier dynamics and para‐glacial erosion rates in tectonically active mountains remain rare. We contribute to filling this knowledge gap and present an unprecedented regional‐scale inventory of supra‐glacial sediment flux and hillslope erosion rates inferred from an analysis of 123 large (> 0·1 km 2 ) catastrophic bedrock landslides that fell onto glaciers in the Chugach Mountains, Alaska, as documented by satellite images obtained between 1972 to 2008. Assuming these supra‐glacial landslide deposits to be passive strain markers we infer minimum decadal‐scale sediment yields of 190 to 7400 t km –2 yr –1 for a given glacier‐surface cross‐section impacted by episodic rock–slope failure. These rates compare to reported fluvial sediment yields in many mountain rivers, but are an order of magnitude below the extreme sediment yields measured at the snouts of Alaskan glaciers, indicating that the bulk of debris discharged derives from en‐glacial, sub‐glacial or ice‐proximal sources. We estimate an average minimum para‐glacial erosion rate by large, episodic rock–slope failures at 0·5–0·7 mm yr –1 in the Chugach Mountains over a 50‐yr period, with earthquakes likely being responsible for up to 73% of this rate. Though ranking amongst the highest decadal landslide erosion rates for this size of study area worldwide, our inferred rates of hillslope erosion in the Chugach Mountains remain an order of magnitude below the pace of extremely rapid glacial sediment export and glacio‐isostatic surface uplift previously reported from the region. Copyright © 2012 John Wiley & Sons, Ltd. Article in Journal/Newspaper glacier glaciers Alaska Wiley Online Library Earth Surface Processes and Landforms 38 7 675 682 |
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Wiley Online Library |
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crwiley |
language |
English |
description |
ABSTRACT The ongoing debate over the effects of global environmental change on Earth's cryosphere calls for detailed knowledge about process rates and their variability in cold environments. In this context, appraisals of the coupling between glacier dynamics and para‐glacial erosion rates in tectonically active mountains remain rare. We contribute to filling this knowledge gap and present an unprecedented regional‐scale inventory of supra‐glacial sediment flux and hillslope erosion rates inferred from an analysis of 123 large (> 0·1 km 2 ) catastrophic bedrock landslides that fell onto glaciers in the Chugach Mountains, Alaska, as documented by satellite images obtained between 1972 to 2008. Assuming these supra‐glacial landslide deposits to be passive strain markers we infer minimum decadal‐scale sediment yields of 190 to 7400 t km –2 yr –1 for a given glacier‐surface cross‐section impacted by episodic rock–slope failure. These rates compare to reported fluvial sediment yields in many mountain rivers, but are an order of magnitude below the extreme sediment yields measured at the snouts of Alaskan glaciers, indicating that the bulk of debris discharged derives from en‐glacial, sub‐glacial or ice‐proximal sources. We estimate an average minimum para‐glacial erosion rate by large, episodic rock–slope failures at 0·5–0·7 mm yr –1 in the Chugach Mountains over a 50‐yr period, with earthquakes likely being responsible for up to 73% of this rate. Though ranking amongst the highest decadal landslide erosion rates for this size of study area worldwide, our inferred rates of hillslope erosion in the Chugach Mountains remain an order of magnitude below the pace of extremely rapid glacial sediment export and glacio‐isostatic surface uplift previously reported from the region. Copyright © 2012 John Wiley & Sons, Ltd. |
format |
Article in Journal/Newspaper |
author |
Uhlmann, Manuela Korup, Oliver Huggel, Christian Fischer, Luzia Kargel, Jeffrey S. |
spellingShingle |
Uhlmann, Manuela Korup, Oliver Huggel, Christian Fischer, Luzia Kargel, Jeffrey S. Supra‐glacial deposition and flux of catastrophic rock–slope failure debris, south‐central Alaska |
author_facet |
Uhlmann, Manuela Korup, Oliver Huggel, Christian Fischer, Luzia Kargel, Jeffrey S. |
author_sort |
Uhlmann, Manuela |
title |
Supra‐glacial deposition and flux of catastrophic rock–slope failure debris, south‐central Alaska |
title_short |
Supra‐glacial deposition and flux of catastrophic rock–slope failure debris, south‐central Alaska |
title_full |
Supra‐glacial deposition and flux of catastrophic rock–slope failure debris, south‐central Alaska |
title_fullStr |
Supra‐glacial deposition and flux of catastrophic rock–slope failure debris, south‐central Alaska |
title_full_unstemmed |
Supra‐glacial deposition and flux of catastrophic rock–slope failure debris, south‐central Alaska |
title_sort |
supra‐glacial deposition and flux of catastrophic rock–slope failure debris, south‐central alaska |
publisher |
Wiley |
publishDate |
2012 |
url |
http://dx.doi.org/10.1002/esp.3311 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fesp.3311 https://onlinelibrary.wiley.com/doi/pdf/10.1002/esp.3311 |
genre |
glacier glaciers Alaska |
genre_facet |
glacier glaciers Alaska |
op_source |
Earth Surface Processes and Landforms volume 38, issue 7, page 675-682 ISSN 0197-9337 1096-9837 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1002/esp.3311 |
container_title |
Earth Surface Processes and Landforms |
container_volume |
38 |
container_issue |
7 |
container_start_page |
675 |
op_container_end_page |
682 |
_version_ |
1800752035971203072 |