Observational constraints on the sensitivity of two calving glaciers to external forcings
Future mass loss projections of the Greenland ice sheet require understanding of the processes at a glacier terminus, especially of iceberg calving. We present detailed and high-rate terrestrial radar interferometer observations of Eqip Sermia and Bowdoin Glacier, two outlet glaciers in Greenland wi...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Cambridge University Press
2023-06-01
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| Series: | Journal of Glaciology |
| Subjects: | |
| Online Access: | https://www.cambridge.org/core/product/identifier/S0022143022000740/type/journal_article |
| _version_ | 1797821741369655296 |
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| author | Andrea Kneib-Walter Martin P. Lüthi Martin Funk Guillaume Jouvet Andreas Vieli |
| author_facet | Andrea Kneib-Walter Martin P. Lüthi Martin Funk Guillaume Jouvet Andreas Vieli |
| author_sort | Andrea Kneib-Walter |
| collection | DOAJ |
| description | Future mass loss projections of the Greenland ice sheet require understanding of the processes at a glacier terminus, especially of iceberg calving. We present detailed and high-rate terrestrial radar interferometer observations of Eqip Sermia and Bowdoin Glacier, two outlet glaciers in Greenland with comparable dimensions and investigate iceberg calving, surface elevation, velocity, strain rates and their links to air temperature, tides and topography. The results reveal that the two glaciers exhibit very different flow and calving behaviour on different timescales. Ice flow driven by a steep surface slope with several topographic steps leads to high velocities, areas of extension and intense crevassing, which triggers frequent but small calving events independent of local velocity gradients. In contrast, ice flow under smooth surface slopes leaves the ice relatively intact, such that sporadic large-scale calving events dominate, which initiate in areas with high shearing. Flow acceleration caused by enhanced meltwater input and tidal velocity variations were observed for terminus sections close to floatation. Firmly grounded terminus sections showed no tidal signal and a weak short-term reaction to air temperature. These results demonstrate reaction timescales to external forcings from hours to months, which are, however, strongly dependent on local terminus geometry. |
| first_indexed | 2024-03-13T09:57:15Z |
| format | Article |
| id | doaj.art-0b0d838088fe42b5b85ccb3cf7e025cf |
| institution | Directory Open Access Journal |
| issn | 0022-1430 1727-5652 |
| language | English |
| last_indexed | 2024-03-13T09:57:15Z |
| publishDate | 2023-06-01 |
| publisher | Cambridge University Press |
| record_format | Article |
| series | Journal of Glaciology |
| spelling | doaj.art-0b0d838088fe42b5b85ccb3cf7e025cf2023-05-23T11:53:18ZengCambridge University PressJournal of Glaciology0022-14301727-56522023-06-016945947410.1017/jog.2022.74Observational constraints on the sensitivity of two calving glaciers to external forcingsAndrea Kneib-Walter0https://orcid.org/0000-0002-0495-785XMartin P. Lüthi1https://orcid.org/0000-0003-4419-8496Martin Funk2Guillaume Jouvet3https://orcid.org/0000-0002-8546-8459Andreas Vieli4Institute of Geography, University of Zurich, Zurich, Switzerland Laboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Zurich, SwitzerlandInstitute of Geography, University of Zurich, Zurich, SwitzerlandLaboratory of Hydraulics, Hydrology and Glaciology, ETH Zurich, Zurich, SwitzerlandInstitute of Geography, University of Zurich, Zurich, SwitzerlandInstitute of Geography, University of Zurich, Zurich, SwitzerlandFuture mass loss projections of the Greenland ice sheet require understanding of the processes at a glacier terminus, especially of iceberg calving. We present detailed and high-rate terrestrial radar interferometer observations of Eqip Sermia and Bowdoin Glacier, two outlet glaciers in Greenland with comparable dimensions and investigate iceberg calving, surface elevation, velocity, strain rates and their links to air temperature, tides and topography. The results reveal that the two glaciers exhibit very different flow and calving behaviour on different timescales. Ice flow driven by a steep surface slope with several topographic steps leads to high velocities, areas of extension and intense crevassing, which triggers frequent but small calving events independent of local velocity gradients. In contrast, ice flow under smooth surface slopes leaves the ice relatively intact, such that sporadic large-scale calving events dominate, which initiate in areas with high shearing. Flow acceleration caused by enhanced meltwater input and tidal velocity variations were observed for terminus sections close to floatation. Firmly grounded terminus sections showed no tidal signal and a weak short-term reaction to air temperature. These results demonstrate reaction timescales to external forcings from hours to months, which are, however, strongly dependent on local terminus geometry.https://www.cambridge.org/core/product/identifier/S0022143022000740/type/journal_articleCalvingglacier calvingglacier monitoringice velocityremote sensing |
| spellingShingle | Andrea Kneib-Walter Martin P. Lüthi Martin Funk Guillaume Jouvet Andreas Vieli Observational constraints on the sensitivity of two calving glaciers to external forcings Journal of Glaciology Calving glacier calving glacier monitoring ice velocity remote sensing |
| title | Observational constraints on the sensitivity of two calving glaciers to external forcings |
| title_full | Observational constraints on the sensitivity of two calving glaciers to external forcings |
| title_fullStr | Observational constraints on the sensitivity of two calving glaciers to external forcings |
| title_full_unstemmed | Observational constraints on the sensitivity of two calving glaciers to external forcings |
| title_short | Observational constraints on the sensitivity of two calving glaciers to external forcings |
| title_sort | observational constraints on the sensitivity of two calving glaciers to external forcings |
| topic | Calving glacier calving glacier monitoring ice velocity remote sensing |
| url | https://www.cambridge.org/core/product/identifier/S0022143022000740/type/journal_article |
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