Modeling debris-covered glaciers: response to steady debris deposition
Debris-covered glaciers are common in rapidly eroding alpine landscapes. When thicker than a few centimeters, surface debris suppresses melt rates. If continuous debris cover is present, ablation rates can be significantly reduced leading to increases in glacier length. In order to quantify feedback...
Published in: | The Cryosphere |
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Format: | Article in Journal/Newspaper |
Language: | English |
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Copernicus Publications
2016
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00013326 2023-05-15T18:32:32+02:00 Modeling debris-covered glaciers: response to steady debris deposition Anderson, Leif S. Anderson, Robert S. 2016-05 electronic https://doi.org/10.5194/tc-10-1105-2016 https://noa.gwlb.de/receive/cop_mods_00013326 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00013282/tc-10-1105-2016.pdf https://tc.copernicus.org/articles/10/1105/2016/tc-10-1105-2016.pdf eng eng Copernicus Publications The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-10-1105-2016 https://noa.gwlb.de/receive/cop_mods_00013326 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00013282/tc-10-1105-2016.pdf https://tc.copernicus.org/articles/10/1105/2016/tc-10-1105-2016.pdf uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2016 ftnonlinearchiv https://doi.org/10.5194/tc-10-1105-2016 2022-02-08T22:55:39Z Debris-covered glaciers are common in rapidly eroding alpine landscapes. When thicker than a few centimeters, surface debris suppresses melt rates. If continuous debris cover is present, ablation rates can be significantly reduced leading to increases in glacier length. In order to quantify feedbacks in the debris–glacier–climate system, we developed a 2-D long-valley numerical glacier model that includes englacial and supraglacial debris advection. We ran 120 simulations on a linear bed profile in which a hypothetical steady state debris-free glacier responds to a step increase of surface debris deposition. Simulated glaciers advance to steady states in which ice accumulation equals ice ablation, and debris input equals debris loss from the glacier terminus. Our model and parameter selections can produce 2-fold increases in glacier length. Debris flux onto the glacier and the relationship between debris thickness and melt rate strongly control glacier length. Debris deposited near the equilibrium-line altitude, where ice discharge is high, results in the greatest glacier extension when other debris-related variables are held constant. Debris deposited near the equilibrium-line altitude re-emerges high in the ablation zone and therefore impacts melt rate over a greater fraction of the glacier surface. Continuous debris cover reduces ice discharge gradients, ice thickness gradients, and velocity gradients relative to initial debris-free glaciers. Debris-forced glacier extension decreases the ratio of accumulation zone to total glacier area (AAR). Our simulations reproduce the "general trends" between debris cover, AARs, and glacier surface velocity patterns from modern debris-covered glaciers. We provide a quantitative, theoretical foundation to interpret the effect of debris cover on the moraine record, and to assess the effects of climate change on debris-covered glaciers. Article in Journal/Newspaper The Cryosphere Niedersächsisches Online-Archiv NOA Long Valley ENVELOPE(-147.800,-147.800,-86.217,-86.217) The Cryosphere 10 3 1105 1124 |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Anderson, Leif S. Anderson, Robert S. Modeling debris-covered glaciers: response to steady debris deposition |
topic_facet |
article Verlagsveröffentlichung |
description |
Debris-covered glaciers are common in rapidly eroding alpine landscapes. When thicker than a few centimeters, surface debris suppresses melt rates. If continuous debris cover is present, ablation rates can be significantly reduced leading to increases in glacier length. In order to quantify feedbacks in the debris–glacier–climate system, we developed a 2-D long-valley numerical glacier model that includes englacial and supraglacial debris advection. We ran 120 simulations on a linear bed profile in which a hypothetical steady state debris-free glacier responds to a step increase of surface debris deposition. Simulated glaciers advance to steady states in which ice accumulation equals ice ablation, and debris input equals debris loss from the glacier terminus. Our model and parameter selections can produce 2-fold increases in glacier length. Debris flux onto the glacier and the relationship between debris thickness and melt rate strongly control glacier length. Debris deposited near the equilibrium-line altitude, where ice discharge is high, results in the greatest glacier extension when other debris-related variables are held constant. Debris deposited near the equilibrium-line altitude re-emerges high in the ablation zone and therefore impacts melt rate over a greater fraction of the glacier surface. Continuous debris cover reduces ice discharge gradients, ice thickness gradients, and velocity gradients relative to initial debris-free glaciers. Debris-forced glacier extension decreases the ratio of accumulation zone to total glacier area (AAR). Our simulations reproduce the "general trends" between debris cover, AARs, and glacier surface velocity patterns from modern debris-covered glaciers. We provide a quantitative, theoretical foundation to interpret the effect of debris cover on the moraine record, and to assess the effects of climate change on debris-covered glaciers. |
format |
Article in Journal/Newspaper |
author |
Anderson, Leif S. Anderson, Robert S. |
author_facet |
Anderson, Leif S. Anderson, Robert S. |
author_sort |
Anderson, Leif S. |
title |
Modeling debris-covered glaciers: response to steady debris deposition |
title_short |
Modeling debris-covered glaciers: response to steady debris deposition |
title_full |
Modeling debris-covered glaciers: response to steady debris deposition |
title_fullStr |
Modeling debris-covered glaciers: response to steady debris deposition |
title_full_unstemmed |
Modeling debris-covered glaciers: response to steady debris deposition |
title_sort |
modeling debris-covered glaciers: response to steady debris deposition |
publisher |
Copernicus Publications |
publishDate |
2016 |
url |
https://doi.org/10.5194/tc-10-1105-2016 https://noa.gwlb.de/receive/cop_mods_00013326 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00013282/tc-10-1105-2016.pdf https://tc.copernicus.org/articles/10/1105/2016/tc-10-1105-2016.pdf |
long_lat |
ENVELOPE(-147.800,-147.800,-86.217,-86.217) |
geographic |
Long Valley |
geographic_facet |
Long Valley |
genre |
The Cryosphere |
genre_facet |
The Cryosphere |
op_relation |
The Cryosphere -- ˜Theœ Cryosphere -- http://www.bibliothek.uni-regensburg.de/ezeit/?2393169 -- http://www.the-cryosphere.net/ -- 1994-0424 https://doi.org/10.5194/tc-10-1105-2016 https://noa.gwlb.de/receive/cop_mods_00013326 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00013282/tc-10-1105-2016.pdf https://tc.copernicus.org/articles/10/1105/2016/tc-10-1105-2016.pdf |
op_rights |
uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/tc-10-1105-2016 |
container_title |
The Cryosphere |
container_volume |
10 |
container_issue |
3 |
container_start_page |
1105 |
op_container_end_page |
1124 |
_version_ |
1766216642849669120 |