Thickness of Ruth Glacier, Alaska, and depth of its Great Gorge from ice-penetrating radar and mass conservation
Ruth Glacier is situated in the Central Alaska Range, with the Don Sheldon Amphitheater comprising much of its broad accumulation area, directly adjacent to North America's tallest mountain, Denali. From there it funnels through the ‘Great Gorge,’ flanked by steep valley walls reaching over 150...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Cambridge University Press
2024-01-01
|
| Series: | Journal of Glaciology |
| Subjects: | |
| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143024000534/type/journal_article |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1841526542507704320 |
|---|---|
| author | Brandon S. Tober Michael S. Christoffersen John W. Holt Martin Truffer Christopher F. Larsen |
| author_facet | Brandon S. Tober Michael S. Christoffersen John W. Holt Martin Truffer Christopher F. Larsen |
| author_sort | Brandon S. Tober |
| collection | DOAJ |
| description | Ruth Glacier is situated in the Central Alaska Range, with the Don Sheldon Amphitheater comprising much of its broad accumulation area, directly adjacent to North America's tallest mountain, Denali. From there it funnels through the ‘Great Gorge,’ flanked by steep valley walls reaching over 1500 m. We combine airborne and ground-based radar measurements of ice thickness with satellite-derived surface velocities to constrain ice flux above and below the gorge, and employ a mass conservation approach to estimate the glacier's thickness within the gorge. We measure ice thickness in the amphitheater to reach 950 m, and estimate centerline thickness in the gorge to range from 610 to 960 m. Our estimates are up to two times greater than those suggested by global models, and allow us to confirm that the Great Gorge rivals Hells Canyon as the deepest gorge in North America. We found that the geometry of the gorge prevents radar measurements of ice thickness there since returns from the subglacial valley walls would precede and potentially occlude nadir bed returns. The same may be true of other unmapped mountain glaciers; however, thickness may be determined using appropriately located flux gates where radar sounding is feasible, combined with mass conservation methods. |
| format | Article |
| id | doaj-art-fbc80c4235774c839e07af7cc0d98141 |
| institution | Kabale University |
| issn | 0022-1430 1727-5652 |
| language | English |
| publishDate | 2024-01-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj-art-fbc80c4235774c839e07af7cc0d981412025-01-16T21:46:33ZengCambridge University PressJournal of Glaciology0022-14301727-56522024-01-017010.1017/jog.2024.53Thickness of Ruth Glacier, Alaska, and depth of its Great Gorge from ice-penetrating radar and mass conservationBrandon S. Tober0https://orcid.org/0000-0001-9010-1646Michael S. Christoffersen1John W. Holt2Martin Truffer3https://orcid.org/0000-0001-8251-7043Christopher F. Larsen4Department of Geosciences, University of Arizona, Tucson, AZ, USA Civil and Environmental Engineering, Carnegie Mellon University, Pittsburgh, PA, USAGeophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, USA Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USADepartment of Geosciences, University of Arizona, Tucson, AZ, USA Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USAGeophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, USA Department of Physics, University of Alaska Fairbanks, Fairbanks, AK, USAGeophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, USARuth Glacier is situated in the Central Alaska Range, with the Don Sheldon Amphitheater comprising much of its broad accumulation area, directly adjacent to North America's tallest mountain, Denali. From there it funnels through the ‘Great Gorge,’ flanked by steep valley walls reaching over 1500 m. We combine airborne and ground-based radar measurements of ice thickness with satellite-derived surface velocities to constrain ice flux above and below the gorge, and employ a mass conservation approach to estimate the glacier's thickness within the gorge. We measure ice thickness in the amphitheater to reach 950 m, and estimate centerline thickness in the gorge to range from 610 to 960 m. Our estimates are up to two times greater than those suggested by global models, and allow us to confirm that the Great Gorge rivals Hells Canyon as the deepest gorge in North America. We found that the geometry of the gorge prevents radar measurements of ice thickness there since returns from the subglacial valley walls would precede and potentially occlude nadir bed returns. The same may be true of other unmapped mountain glaciers; however, thickness may be determined using appropriately located flux gates where radar sounding is feasible, combined with mass conservation methods.https://www.cambridge.org/core/product/identifier/S0022143024000534/type/journal_articleradio-echo soundingremote sensingice thickness measurementsglacier geophysicsglacier modeling |
| spellingShingle | Brandon S. Tober Michael S. Christoffersen John W. Holt Martin Truffer Christopher F. Larsen Thickness of Ruth Glacier, Alaska, and depth of its Great Gorge from ice-penetrating radar and mass conservation Journal of Glaciology radio-echo sounding remote sensing ice thickness measurements glacier geophysics glacier modeling |
| title | Thickness of Ruth Glacier, Alaska, and depth of its Great Gorge from ice-penetrating radar and mass conservation |
| title_full | Thickness of Ruth Glacier, Alaska, and depth of its Great Gorge from ice-penetrating radar and mass conservation |
| title_fullStr | Thickness of Ruth Glacier, Alaska, and depth of its Great Gorge from ice-penetrating radar and mass conservation |
| title_full_unstemmed | Thickness of Ruth Glacier, Alaska, and depth of its Great Gorge from ice-penetrating radar and mass conservation |
| title_short | Thickness of Ruth Glacier, Alaska, and depth of its Great Gorge from ice-penetrating radar and mass conservation |
| title_sort | thickness of ruth glacier alaska and depth of its great gorge from ice penetrating radar and mass conservation |
| topic | radio-echo sounding remote sensing ice thickness measurements glacier geophysics glacier modeling |
| url | https://www.cambridge.org/core/product/identifier/S0022143024000534/type/journal_article |
| work_keys_str_mv | AT brandonstober thicknessofruthglacieralaskaanddepthofitsgreatgorgefromicepenetratingradarandmassconservation AT michaelschristoffersen thicknessofruthglacieralaskaanddepthofitsgreatgorgefromicepenetratingradarandmassconservation AT johnwholt thicknessofruthglacieralaskaanddepthofitsgreatgorgefromicepenetratingradarandmassconservation AT martintruffer thicknessofruthglacieralaskaanddepthofitsgreatgorgefromicepenetratingradarandmassconservation AT christopherflarsen thicknessofruthglacieralaskaanddepthofitsgreatgorgefromicepenetratingradarandmassconservation |