Flow Dynamics of an Accumulation Basin: A Case Study of Upper Kahiltna Glacier, Mount McKinley, Alaska
We interpreted flow dynamics of the Kahiltna Pass Basin accumulation zone on Mount McKinley, Alaska, USA, using 40, 100 and 900 MHz ground-penetrating radar profiles and GPS surface velocity measurements. We found dipping, englacial surface-conformable strata that experienced vertical thickening as...
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ftdartmouthcoll:oai:digitalcommons.dartmouth.edu:facoa-2762 2023-07-16T03:58:33+02:00 Flow Dynamics of an Accumulation Basin: A Case Study of Upper Kahiltna Glacier, Mount McKinley, Alaska Campbell, Seth Kreutz, Karl Osterberg, Erich Arcone, Steven 2011-11-14T08:00:00Z application/pdf https://digitalcommons.dartmouth.edu/facoa/1759 https://doi.org/10.3189/2012JoG10J233 https://digitalcommons.dartmouth.edu/context/facoa/article/2762/viewcontent/flow_dynamics_of_an_accumulation_basin_a_case_study_of_upper_kahiltna_glacier_mount_mckinley_alaska.pdf unknown Dartmouth Digital Commons https://digitalcommons.dartmouth.edu/facoa/1759 doi:10.3189/2012JoG10J233 https://digitalcommons.dartmouth.edu/context/facoa/article/2762/viewcontent/flow_dynamics_of_an_accumulation_basin_a_case_study_of_upper_kahiltna_glacier_mount_mckinley_alaska.pdf Dartmouth Scholarship Earth Sciences Glaciology Physical Sciences and Mathematics text 2011 ftdartmouthcoll https://doi.org/10.3189/2012JoG10J233 2023-06-28T10:40:09Z We interpreted flow dynamics of the Kahiltna Pass Basin accumulation zone on Mount McKinley, Alaska, USA, using 40, 100 and 900 MHz ground-penetrating radar profiles and GPS surface velocity measurements. We found dipping, englacial surface-conformable strata that experienced vertical thickening as the glacier flowed westward from a steep, higher-velocity (60 m a−1) region into flat terrain associated with a 90° bend in the glacier and lower velocities (15 m a−1) to the south. Stratigraphy near the western side of the basin was surface-conformable to ∼170 m depth and thinned as flow diverged southward, down-glacier. We found complex strata beneath the conformable stratigraphy and interpret these features as buried crevasses, avalanche debris and deformed ice caused by up-glacier events. We also suggest that basin dimensions, bed topography and the sharp bend each cause flow extension and compression, significantly contributing to conformable and complex strata thickness variations. Our findings show that surface-conformable stratigraphy continuous with depth and consistent strata thicknesses cannot be assumed in accumulation basins, because local and up-glacier terrain and flow dynamics can cause structural complexities to occur under and within surface-conformable layers. Text glacier Alaska Dartmouth Digital Commons (Dartmouth College) Journal of Glaciology 58 207 185 195 |
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topic |
Earth Sciences Glaciology Physical Sciences and Mathematics |
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Earth Sciences Glaciology Physical Sciences and Mathematics Campbell, Seth Kreutz, Karl Osterberg, Erich Arcone, Steven Flow Dynamics of an Accumulation Basin: A Case Study of Upper Kahiltna Glacier, Mount McKinley, Alaska |
topic_facet |
Earth Sciences Glaciology Physical Sciences and Mathematics |
description |
We interpreted flow dynamics of the Kahiltna Pass Basin accumulation zone on Mount McKinley, Alaska, USA, using 40, 100 and 900 MHz ground-penetrating radar profiles and GPS surface velocity measurements. We found dipping, englacial surface-conformable strata that experienced vertical thickening as the glacier flowed westward from a steep, higher-velocity (60 m a−1) region into flat terrain associated with a 90° bend in the glacier and lower velocities (15 m a−1) to the south. Stratigraphy near the western side of the basin was surface-conformable to ∼170 m depth and thinned as flow diverged southward, down-glacier. We found complex strata beneath the conformable stratigraphy and interpret these features as buried crevasses, avalanche debris and deformed ice caused by up-glacier events. We also suggest that basin dimensions, bed topography and the sharp bend each cause flow extension and compression, significantly contributing to conformable and complex strata thickness variations. Our findings show that surface-conformable stratigraphy continuous with depth and consistent strata thicknesses cannot be assumed in accumulation basins, because local and up-glacier terrain and flow dynamics can cause structural complexities to occur under and within surface-conformable layers. |
format |
Text |
author |
Campbell, Seth Kreutz, Karl Osterberg, Erich Arcone, Steven |
author_facet |
Campbell, Seth Kreutz, Karl Osterberg, Erich Arcone, Steven |
author_sort |
Campbell, Seth |
title |
Flow Dynamics of an Accumulation Basin: A Case Study of Upper Kahiltna Glacier, Mount McKinley, Alaska |
title_short |
Flow Dynamics of an Accumulation Basin: A Case Study of Upper Kahiltna Glacier, Mount McKinley, Alaska |
title_full |
Flow Dynamics of an Accumulation Basin: A Case Study of Upper Kahiltna Glacier, Mount McKinley, Alaska |
title_fullStr |
Flow Dynamics of an Accumulation Basin: A Case Study of Upper Kahiltna Glacier, Mount McKinley, Alaska |
title_full_unstemmed |
Flow Dynamics of an Accumulation Basin: A Case Study of Upper Kahiltna Glacier, Mount McKinley, Alaska |
title_sort |
flow dynamics of an accumulation basin: a case study of upper kahiltna glacier, mount mckinley, alaska |
publisher |
Dartmouth Digital Commons |
publishDate |
2011 |
url |
https://digitalcommons.dartmouth.edu/facoa/1759 https://doi.org/10.3189/2012JoG10J233 https://digitalcommons.dartmouth.edu/context/facoa/article/2762/viewcontent/flow_dynamics_of_an_accumulation_basin_a_case_study_of_upper_kahiltna_glacier_mount_mckinley_alaska.pdf |
genre |
glacier Alaska |
genre_facet |
glacier Alaska |
op_source |
Dartmouth Scholarship |
op_relation |
https://digitalcommons.dartmouth.edu/facoa/1759 doi:10.3189/2012JoG10J233 https://digitalcommons.dartmouth.edu/context/facoa/article/2762/viewcontent/flow_dynamics_of_an_accumulation_basin_a_case_study_of_upper_kahiltna_glacier_mount_mckinley_alaska.pdf |
op_doi |
https://doi.org/10.3189/2012JoG10J233 |
container_title |
Journal of Glaciology |
container_volume |
58 |
container_issue |
207 |
container_start_page |
185 |
op_container_end_page |
195 |
_version_ |
1771545695529992192 |