Evolution of sub-ice-shelf channels reveals changes in ocean-driven melt in West Antarctica
Basal channels, which are troughs carved into the undersides of ice shelves by buoyant plumes of water, are modulators of ice-shelf basal melt and structural stability. In this study, we track the evolution of 12 large basal channels beneath ice shelves of the Amundsen and Bellingshausen seas region...
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Cambridge University Press
2024-01-01
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| Series: | Journal of Glaciology |
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| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143024000200/type/journal_article |
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| author | Karen E. Alley Richard B. Alley Alex D. Crawford Naomi Ochwat Christian T. Wild Juliana Marson Tasha Snow Atsuhiro Muto Erin C. Pettit Sarah F. Child Martin Truffer Gabriela Collao-Barrios Ted A. Scambos |
| author_facet | Karen E. Alley Richard B. Alley Alex D. Crawford Naomi Ochwat Christian T. Wild Juliana Marson Tasha Snow Atsuhiro Muto Erin C. Pettit Sarah F. Child Martin Truffer Gabriela Collao-Barrios Ted A. Scambos |
| author_sort | Karen E. Alley |
| collection | DOAJ |
| description | Basal channels, which are troughs carved into the undersides of ice shelves by buoyant plumes of water, are modulators of ice-shelf basal melt and structural stability. In this study, we track the evolution of 12 large basal channels beneath ice shelves of the Amundsen and Bellingshausen seas region in West Antarctica using the Landsat record since its start in the 1970s through 2020. We observe examples of channel growth, interactions with ice-shelf features, and systematic changes in sinuosity that give insight into the life cycles of basal channels. We use the last two decades of the record, combined with contemporary ice-flow velocity datasets, to separate channel-path evolution into components related to advection by ice flow and those controlled by other forcings, such as ocean melt or surface accumulation. Our results show that ice-flow-independent lateral channel migration is overwhelmingly to the left when viewed down-flow, suggesting that it is dominated by Coriolis-influenced ocean melt. By applying a model of channel-path evolution dominantly controlled by ice flow and ocean melt, we show that the majority of channels surveyed exhibit non-steady behavior that serves as a novel proxy for increased ocean forcing in West Antarctica starting at least in the early 1970s. |
| format | Article |
| id | doaj-art-9d3b4025915648598961db0373808eb4 |
| 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-9d3b4025915648598961db0373808eb42025-01-16T21:48:39ZengCambridge University PressJournal of Glaciology0022-14301727-56522024-01-017010.1017/jog.2024.20Evolution of sub-ice-shelf channels reveals changes in ocean-driven melt in West AntarcticaKaren E. Alley0https://orcid.org/0000-0003-0358-3806Richard B. Alley1https://orcid.org/0000-0003-1833-0115Alex D. Crawford2https://orcid.org/0000-0003-1561-290XNaomi Ochwat3https://orcid.org/0000-0002-7855-1772Christian T. Wild4https://orcid.org/0000-0003-4586-1704Juliana Marson5https://orcid.org/0000-0001-5074-7370Tasha Snow6https://orcid.org/0000-0001-5697-5470Atsuhiro Muto7https://orcid.org/0000-0002-1722-2457Erin C. Pettit8https://orcid.org/0000-0002-6765-9841Sarah F. Child9https://orcid.org/0000-0003-0677-2119Martin Truffer10https://orcid.org/0000-0001-8251-7043Gabriela Collao-Barrios11Ted A. Scambos12https://orcid.org/0000-0003-4268-6322Department of Environment and Geography, University of Manitoba, Winnipeg, MB, CanadaDepartment of Geosciences, Pennsylvania State University, State College, PA, USADepartment of Environment and Geography, University of Manitoba, Winnipeg, MB, CanadaCooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USADepartment of Geosciences, University of Tübingen, Tübingen, GermanyDepartment of Environment and Geography, University of Manitoba, Winnipeg, MB, CanadaDepartment of Geophysics, Colorado School of Mines, Golden, CO, USADepartment of Earth and Environmental Science, Temple University, Philadelphia, PA, USACollege of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USACooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USADepartment of Physics, University of Alaska Fairbanks, Fairbanks, AK, USACooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USACooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USABasal channels, which are troughs carved into the undersides of ice shelves by buoyant plumes of water, are modulators of ice-shelf basal melt and structural stability. In this study, we track the evolution of 12 large basal channels beneath ice shelves of the Amundsen and Bellingshausen seas region in West Antarctica using the Landsat record since its start in the 1970s through 2020. We observe examples of channel growth, interactions with ice-shelf features, and systematic changes in sinuosity that give insight into the life cycles of basal channels. We use the last two decades of the record, combined with contemporary ice-flow velocity datasets, to separate channel-path evolution into components related to advection by ice flow and those controlled by other forcings, such as ocean melt or surface accumulation. Our results show that ice-flow-independent lateral channel migration is overwhelmingly to the left when viewed down-flow, suggesting that it is dominated by Coriolis-influenced ocean melt. By applying a model of channel-path evolution dominantly controlled by ice flow and ocean melt, we show that the majority of channels surveyed exhibit non-steady behavior that serves as a novel proxy for increased ocean forcing in West Antarctica starting at least in the early 1970s.https://www.cambridge.org/core/product/identifier/S0022143024000200/type/journal_articleice and climateice/ocean interactionsice shelves |
| spellingShingle | Karen E. Alley Richard B. Alley Alex D. Crawford Naomi Ochwat Christian T. Wild Juliana Marson Tasha Snow Atsuhiro Muto Erin C. Pettit Sarah F. Child Martin Truffer Gabriela Collao-Barrios Ted A. Scambos Evolution of sub-ice-shelf channels reveals changes in ocean-driven melt in West Antarctica Journal of Glaciology ice and climate ice/ocean interactions ice shelves |
| title | Evolution of sub-ice-shelf channels reveals changes in ocean-driven melt in West Antarctica |
| title_full | Evolution of sub-ice-shelf channels reveals changes in ocean-driven melt in West Antarctica |
| title_fullStr | Evolution of sub-ice-shelf channels reveals changes in ocean-driven melt in West Antarctica |
| title_full_unstemmed | Evolution of sub-ice-shelf channels reveals changes in ocean-driven melt in West Antarctica |
| title_short | Evolution of sub-ice-shelf channels reveals changes in ocean-driven melt in West Antarctica |
| title_sort | evolution of sub ice shelf channels reveals changes in ocean driven melt in west antarctica |
| topic | ice and climate ice/ocean interactions ice shelves |
| url | https://www.cambridge.org/core/product/identifier/S0022143024000200/type/journal_article |
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