Changing glaciers in the Brooks Range and western Chugach Mountains, Alaska: mass loss, runoff increase, and supraglacial volcanic tephra coverage
Dissertation (Ph.D.) University of Alaska Fairbanks, 2020 Glaciers in Alaska cover over ~87,000 km² (~ 6 % of the state) with most glaciers thinning and retreating at an increasing rate. The thinning and retreating of glaciers worldwide can have an immediate socio-economic implication in addition to...
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ftunivalaska:oai:scholarworks.alaska.edu:11122/12398 2023-05-15T15:18:31+02:00 Changing glaciers in the Brooks Range and western Chugach Mountains, Alaska: mass loss, runoff increase, and supraglacial volcanic tephra coverage Geck, Jason Hock, Regine Coakley, Bernard Dial, Roman Loso, Michael 2020-12 http://hdl.handle.net/11122/12398 en_US eng http://hdl.handle.net/11122/12398 Department of Geosciences Glaciers Brooks Range Volcanic ash Chugach Mountains Runoff Mount Spurr Eklutna Glacier Doctor of Philosophy in Geology Dissertation phd 2020 ftunivalaska 2023-02-23T21:37:54Z Dissertation (Ph.D.) University of Alaska Fairbanks, 2020 Glaciers in Alaska cover over ~87,000 km² (~ 6 % of the state) with most glaciers thinning and retreating at an increasing rate. The thinning and retreating of glaciers worldwide can have an immediate socio-economic implication in addition to the longer-term glacier meltwater contribution to sea level rise. This dissertation investigated Alaskan glaciers in the Brooks Range for mass loss and area reductions over the period 1970-2001 (Chapter 2), historic mass balance and runoff for Eklutna Glacier, located in western Chugach Mountains, using a temperature index model over 1984-2019 period (Chapter 3), and the persistence of tephra from a volcanic eruption of Mt. Spurr in 1992 on seven western Chugach Mountain glaciers (Chapter 4). Glaciers in the Brooks Range in Arctic Alaska (> 68° N) are important indicators of climate change and provide information on long-term climate variations in an area that has few high elevation meteorological stations. Digital elevation models (DEMs) reconstructed from topographic maps were differenced from an interferometric synthetic aperture radar DEM to calculate the volume and mass changes of 107 glaciers (42 km²). Over the period 1970-2001, total ice volume loss was 0.69 ± 0.06 km³ corresponding to a mean (area-weighted) specific mass balance rate of -0.54 ± 0.05 m w.e. a⁻¹ (± uncertainty). The arithmetic mean of all glaciers' specific mass balance rates was -0.47 ± 0.27 m w.e. a⁻¹ (± 1 std. dev.). A subsample of 36 glaciers found a 26 ± 16 % mean area reduction over ~35 years. Alaska's largest city, Anchorage, is critically dependent upon the melt water of Eklutna Glacier (29 km²) for both drinking water and hydropower generation; however, the glacier is rapidly retreating. We used a temperature index model to reconstruct the glacier's mass balance for the period 1985-2019 and quantify the impacts of glacier change on runoff. Eklutna Glacier experienced a significant annual mean surface mass balance negative trend ... Doctoral or Postdoctoral Thesis Arctic Brooks Range Climate change glacier glaciers Alaska University of Alaska: ScholarWorks@UA Anchorage Arctic Fairbanks |
institution |
Open Polar |
collection |
University of Alaska: ScholarWorks@UA |
op_collection_id |
ftunivalaska |
language |
English |
topic |
Glaciers Brooks Range Volcanic ash Chugach Mountains Runoff Mount Spurr Eklutna Glacier Doctor of Philosophy in Geology |
spellingShingle |
Glaciers Brooks Range Volcanic ash Chugach Mountains Runoff Mount Spurr Eklutna Glacier Doctor of Philosophy in Geology Geck, Jason Changing glaciers in the Brooks Range and western Chugach Mountains, Alaska: mass loss, runoff increase, and supraglacial volcanic tephra coverage |
topic_facet |
Glaciers Brooks Range Volcanic ash Chugach Mountains Runoff Mount Spurr Eklutna Glacier Doctor of Philosophy in Geology |
description |
Dissertation (Ph.D.) University of Alaska Fairbanks, 2020 Glaciers in Alaska cover over ~87,000 km² (~ 6 % of the state) with most glaciers thinning and retreating at an increasing rate. The thinning and retreating of glaciers worldwide can have an immediate socio-economic implication in addition to the longer-term glacier meltwater contribution to sea level rise. This dissertation investigated Alaskan glaciers in the Brooks Range for mass loss and area reductions over the period 1970-2001 (Chapter 2), historic mass balance and runoff for Eklutna Glacier, located in western Chugach Mountains, using a temperature index model over 1984-2019 period (Chapter 3), and the persistence of tephra from a volcanic eruption of Mt. Spurr in 1992 on seven western Chugach Mountain glaciers (Chapter 4). Glaciers in the Brooks Range in Arctic Alaska (> 68° N) are important indicators of climate change and provide information on long-term climate variations in an area that has few high elevation meteorological stations. Digital elevation models (DEMs) reconstructed from topographic maps were differenced from an interferometric synthetic aperture radar DEM to calculate the volume and mass changes of 107 glaciers (42 km²). Over the period 1970-2001, total ice volume loss was 0.69 ± 0.06 km³ corresponding to a mean (area-weighted) specific mass balance rate of -0.54 ± 0.05 m w.e. a⁻¹ (± uncertainty). The arithmetic mean of all glaciers' specific mass balance rates was -0.47 ± 0.27 m w.e. a⁻¹ (± 1 std. dev.). A subsample of 36 glaciers found a 26 ± 16 % mean area reduction over ~35 years. Alaska's largest city, Anchorage, is critically dependent upon the melt water of Eklutna Glacier (29 km²) for both drinking water and hydropower generation; however, the glacier is rapidly retreating. We used a temperature index model to reconstruct the glacier's mass balance for the period 1985-2019 and quantify the impacts of glacier change on runoff. Eklutna Glacier experienced a significant annual mean surface mass balance negative trend ... |
author2 |
Hock, Regine Coakley, Bernard Dial, Roman Loso, Michael |
format |
Doctoral or Postdoctoral Thesis |
author |
Geck, Jason |
author_facet |
Geck, Jason |
author_sort |
Geck, Jason |
title |
Changing glaciers in the Brooks Range and western Chugach Mountains, Alaska: mass loss, runoff increase, and supraglacial volcanic tephra coverage |
title_short |
Changing glaciers in the Brooks Range and western Chugach Mountains, Alaska: mass loss, runoff increase, and supraglacial volcanic tephra coverage |
title_full |
Changing glaciers in the Brooks Range and western Chugach Mountains, Alaska: mass loss, runoff increase, and supraglacial volcanic tephra coverage |
title_fullStr |
Changing glaciers in the Brooks Range and western Chugach Mountains, Alaska: mass loss, runoff increase, and supraglacial volcanic tephra coverage |
title_full_unstemmed |
Changing glaciers in the Brooks Range and western Chugach Mountains, Alaska: mass loss, runoff increase, and supraglacial volcanic tephra coverage |
title_sort |
changing glaciers in the brooks range and western chugach mountains, alaska: mass loss, runoff increase, and supraglacial volcanic tephra coverage |
publishDate |
2020 |
url |
http://hdl.handle.net/11122/12398 |
geographic |
Anchorage Arctic Fairbanks |
geographic_facet |
Anchorage Arctic Fairbanks |
genre |
Arctic Brooks Range Climate change glacier glaciers Alaska |
genre_facet |
Arctic Brooks Range Climate change glacier glaciers Alaska |
op_relation |
http://hdl.handle.net/11122/12398 Department of Geosciences |
_version_ |
1766348708419469312 |