Kinematics of the exceptionally-short surge cycles of Sít’ Kusá (Turner Glacier), Alaska, from 1983 to 2013
Glacier surges are periodic episodes of mass redistribution characterized by dramatic increases in ice flow velocity and, sometimes, terminus advance. We use optical satellite imagery to document five previously unexamined surge events of Sít’ Kusá (Turner Glacier) in the St. Elias Mountains of Alas...
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2021-08-01
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| Series: | Journal of Glaciology |
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| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143021000290/type/journal_article |
| _version_ | 1811155829368291328 |
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| author | Andrew Nolan William Kochtitzky Ellyn M. Enderlin Robert McNabb Karl J. Kreutz |
| author_facet | Andrew Nolan William Kochtitzky Ellyn M. Enderlin Robert McNabb Karl J. Kreutz |
| author_sort | Andrew Nolan |
| collection | DOAJ |
| description | Glacier surges are periodic episodes of mass redistribution characterized by dramatic increases in ice flow velocity and, sometimes, terminus advance. We use optical satellite imagery to document five previously unexamined surge events of Sít’ Kusá (Turner Glacier) in the St. Elias Mountains of Alaska from 1983 to 2013. Surge events had an average recurrence interval of ~5 years, making it the shortest known regular recurrence interval in the world. Surge events appear to initiate in the winter, with speeds reaching up to ~25 m d−1. The surges propagate down-glacier over ~2 years, resulting in maximum thinning of ~100 m in the reservoir zone and comparable thickening at the terminus. Collectively, the rapid recurrence interval, winter initiation and down-glacier propagation suggest Sít’ Kusá's surges are driven by periodic changes in subglacial hydrology and glacier sliding. Elevation change observations from the northern tributary show a kinematic disconnect above and below an icefall located 23 km from the terminus. We suggest the kinematic disconnect inhibits drawdown from the accumulation zone above the icefall, which leads to a steady flux of ice into the reservoir zone, and contributes to the glacier's exceptionally short recurrence interval. |
| first_indexed | 2024-04-10T04:40:10Z |
| format | Article |
| id | doaj.art-e0fc42a5944441efacb819c6a75235cc |
| institution | Directory Open Access Journal |
| issn | 0022-1430 1727-5652 |
| language | English |
| last_indexed | 2024-04-10T04:40:10Z |
| publishDate | 2021-08-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj.art-e0fc42a5944441efacb819c6a75235cc2023-03-09T12:41:07ZengCambridge University PressJournal of Glaciology0022-14301727-56522021-08-016774475810.1017/jog.2021.29Kinematics of the exceptionally-short surge cycles of Sít’ Kusá (Turner Glacier), Alaska, from 1983 to 2013Andrew Nolan0https://orcid.org/0000-0002-9785-0196William Kochtitzky1https://orcid.org/0000-0001-9487-1509Ellyn M. Enderlin2https://orcid.org/0000-0002-8266-7719Robert McNabb3https://orcid.org/0000-0003-0016-493XKarl J. Kreutz4https://orcid.org/0000-0003-1881-2341School of Earth and Climate Sciences, University of Maine, Orono, ME, USASchool of Earth and Climate Sciences, University of Maine, Orono, ME, USA Climate Change Institute, University of Maine, Orono, ME, USADepartment of Geosciences, Boise State University, Boise, ID, USASchool of Geography and Environmental Sciences, Ulster University, Coleraine, United Kingdom Department of Geosciences, University of Oslo, Oslo, NorwaySchool of Earth and Climate Sciences, University of Maine, Orono, ME, USA Climate Change Institute, University of Maine, Orono, ME, USAGlacier surges are periodic episodes of mass redistribution characterized by dramatic increases in ice flow velocity and, sometimes, terminus advance. We use optical satellite imagery to document five previously unexamined surge events of Sít’ Kusá (Turner Glacier) in the St. Elias Mountains of Alaska from 1983 to 2013. Surge events had an average recurrence interval of ~5 years, making it the shortest known regular recurrence interval in the world. Surge events appear to initiate in the winter, with speeds reaching up to ~25 m d−1. The surges propagate down-glacier over ~2 years, resulting in maximum thinning of ~100 m in the reservoir zone and comparable thickening at the terminus. Collectively, the rapid recurrence interval, winter initiation and down-glacier propagation suggest Sít’ Kusá's surges are driven by periodic changes in subglacial hydrology and glacier sliding. Elevation change observations from the northern tributary show a kinematic disconnect above and below an icefall located 23 km from the terminus. We suggest the kinematic disconnect inhibits drawdown from the accumulation zone above the icefall, which leads to a steady flux of ice into the reservoir zone, and contributes to the glacier's exceptionally short recurrence interval.https://www.cambridge.org/core/product/identifier/S0022143021000290/type/journal_articleGlacier surgesglacier hazardsremote sensing |
| spellingShingle | Andrew Nolan William Kochtitzky Ellyn M. Enderlin Robert McNabb Karl J. Kreutz Kinematics of the exceptionally-short surge cycles of Sít’ Kusá (Turner Glacier), Alaska, from 1983 to 2013 Journal of Glaciology Glacier surges glacier hazards remote sensing |
| title | Kinematics of the exceptionally-short surge cycles of Sít’ Kusá (Turner Glacier), Alaska, from 1983 to 2013 |
| title_full | Kinematics of the exceptionally-short surge cycles of Sít’ Kusá (Turner Glacier), Alaska, from 1983 to 2013 |
| title_fullStr | Kinematics of the exceptionally-short surge cycles of Sít’ Kusá (Turner Glacier), Alaska, from 1983 to 2013 |
| title_full_unstemmed | Kinematics of the exceptionally-short surge cycles of Sít’ Kusá (Turner Glacier), Alaska, from 1983 to 2013 |
| title_short | Kinematics of the exceptionally-short surge cycles of Sít’ Kusá (Turner Glacier), Alaska, from 1983 to 2013 |
| title_sort | kinematics of the exceptionally short surge cycles of sit kusa turner glacier alaska from 1983 to 2013 |
| topic | Glacier surges glacier hazards remote sensing |
| url | https://www.cambridge.org/core/product/identifier/S0022143021000290/type/journal_article |
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