Thinning leads to calving-style changes at Bowdoin Glacier, Greenland
<p>Ice mass loss from the Greenland ice sheet is the largest single contributor to sea level rise in the 21st century. The mass loss rate has accelerated in recent decades mainly due to thinning and retreat of its outlet glaciers. The diverse calving mechanisms responsible for tidewater glacie...
| Main Authors: | , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2021-02-01
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| Series: | The Cryosphere |
| Online Access: | https://tc.copernicus.org/articles/15/485/2021/tc-15-485-2021.pdf |
| _version_ | 1818958248133263360 |
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| author | E. C. H. van Dongen G. Jouvet G. Jouvet S. Sugiyama E. A. Podolskiy M. Funk D. I. Benn F. Lindner F. Lindner A. Bauder J. Seguinot S. Leinss F. Walter |
| author_facet | E. C. H. van Dongen G. Jouvet G. Jouvet S. Sugiyama E. A. Podolskiy M. Funk D. I. Benn F. Lindner F. Lindner A. Bauder J. Seguinot S. Leinss F. Walter |
| author_sort | E. C. H. van Dongen |
| collection | DOAJ |
| description | <p>Ice mass loss from the Greenland ice sheet is the largest single contributor to sea level rise in the 21st century. The mass loss rate has accelerated in recent decades mainly due to thinning and retreat of its outlet glaciers. The diverse calving mechanisms responsible for tidewater glacier retreat are not fully understood yet. Since a tidewater glacier’s sensitivity to external forcings depends on its calving style, detailed insight into calving processes is necessary to improve projections of ice sheet mass loss by calving. As tidewater glaciers are mostly thinning, their calving styles are expected to change. Here, we study calving behaviour changes under a thinning regime at Bowdoin Glacier, north-western Greenland, by combining field and remote-sensing data from 2015 to 2019. Previous studies showed that major calving events in 2015 and 2017 were driven by hydro-fracturing and melt-undercutting. New observations from uncrewed aerial vehicle (UAV) imagery and a GPS network installed at the calving front in 2019 suggest ungrounding and buoyant calving have recently occurred as they show (1) increasing tidal modulation of vertical motion compared to previous years, (2) absence of a surface crevasse prior to calving, and (3) uplift and horizontal surface compression prior to calving. Furthermore, an inventory of calving events from 2015 to 2019 based on satellite imagery provides additional support for a change towards buoyant calving since it shows an increasing occurrence of calving events outside of the melt season. The observed change in calving style could lead to a possible retreat of the terminus, which has been stable since 2013. We therefore highlight the need for high-resolution monitoring to detect changing calving styles and numerical models that cover the full spectrum of calving mechanisms to improve projections of ice sheet mass loss by calving.</p> |
| first_indexed | 2024-12-20T11:22:43Z |
| format | Article |
| id | doaj.art-062605cf99414de6a26b84793de722bc |
| institution | Directory Open Access Journal |
| issn | 1994-0416 1994-0424 |
| language | English |
| last_indexed | 2024-12-20T11:22:43Z |
| publishDate | 2021-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | The Cryosphere |
| spelling | doaj.art-062605cf99414de6a26b84793de722bc2022-12-21T19:42:27ZengCopernicus PublicationsThe Cryosphere1994-04161994-04242021-02-011548550010.5194/tc-15-485-2021Thinning leads to calving-style changes at Bowdoin Glacier, GreenlandE. C. H. van Dongen0G. Jouvet1G. Jouvet2S. Sugiyama3E. A. Podolskiy4M. Funk5D. I. Benn6F. Lindner7F. Lindner8A. Bauder9J. Seguinot10S. Leinss11F. Walter12Laboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, SwitzerlandDepartment of Geography, University of Zurich, Zurich, SwitzerlandAutonomous Systems Laboratory, ETH Zurich, Zurich, SwitzerlandInstitute of Low Temperature Science, Hokkaido University, Sapporo, JapanInstitute of Low Temperature Science, Hokkaido University, Sapporo, JapanLaboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, SwitzerlandDepartment of Geography and Sustainable Development, University of St Andrews, St Andrews, UKLaboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, SwitzerlandDepartment of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Munich, GermanyLaboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, SwitzerlandLaboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, SwitzerlandInstitute of Environmental Engineering, ETH Zurich, Zurich, SwitzerlandLaboratory of Hydraulics, Hydrology and Glaciology (VAW), ETH Zurich, Zurich, Switzerland<p>Ice mass loss from the Greenland ice sheet is the largest single contributor to sea level rise in the 21st century. The mass loss rate has accelerated in recent decades mainly due to thinning and retreat of its outlet glaciers. The diverse calving mechanisms responsible for tidewater glacier retreat are not fully understood yet. Since a tidewater glacier’s sensitivity to external forcings depends on its calving style, detailed insight into calving processes is necessary to improve projections of ice sheet mass loss by calving. As tidewater glaciers are mostly thinning, their calving styles are expected to change. Here, we study calving behaviour changes under a thinning regime at Bowdoin Glacier, north-western Greenland, by combining field and remote-sensing data from 2015 to 2019. Previous studies showed that major calving events in 2015 and 2017 were driven by hydro-fracturing and melt-undercutting. New observations from uncrewed aerial vehicle (UAV) imagery and a GPS network installed at the calving front in 2019 suggest ungrounding and buoyant calving have recently occurred as they show (1) increasing tidal modulation of vertical motion compared to previous years, (2) absence of a surface crevasse prior to calving, and (3) uplift and horizontal surface compression prior to calving. Furthermore, an inventory of calving events from 2015 to 2019 based on satellite imagery provides additional support for a change towards buoyant calving since it shows an increasing occurrence of calving events outside of the melt season. The observed change in calving style could lead to a possible retreat of the terminus, which has been stable since 2013. We therefore highlight the need for high-resolution monitoring to detect changing calving styles and numerical models that cover the full spectrum of calving mechanisms to improve projections of ice sheet mass loss by calving.</p>https://tc.copernicus.org/articles/15/485/2021/tc-15-485-2021.pdf |
| spellingShingle | E. C. H. van Dongen G. Jouvet G. Jouvet S. Sugiyama E. A. Podolskiy M. Funk D. I. Benn F. Lindner F. Lindner A. Bauder J. Seguinot S. Leinss F. Walter Thinning leads to calving-style changes at Bowdoin Glacier, Greenland The Cryosphere |
| title | Thinning leads to calving-style changes at Bowdoin Glacier, Greenland |
| title_full | Thinning leads to calving-style changes at Bowdoin Glacier, Greenland |
| title_fullStr | Thinning leads to calving-style changes at Bowdoin Glacier, Greenland |
| title_full_unstemmed | Thinning leads to calving-style changes at Bowdoin Glacier, Greenland |
| title_short | Thinning leads to calving-style changes at Bowdoin Glacier, Greenland |
| title_sort | thinning leads to calving style changes at bowdoin glacier greenland |
| url | https://tc.copernicus.org/articles/15/485/2021/tc-15-485-2021.pdf |
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