Estimating Spring Terminus Submarine Melt Rates at a Greenlandic Tidewater Glacier Using Satellite Imagery
Oceanic forcing of the Greenland Ice Sheet is believed to promote widespread thinning at tidewater glaciers, with submarine melting proposed as a potential trigger of increased glacier calving, retreat, and subsequent acceleration. The precise mechanism(s) driving glacier instability, however, remai...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2017-12-01
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| Series: | Frontiers in Earth Science |
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| Online Access: | http://journal.frontiersin.org/article/10.3389/feart.2017.00107/full |
| _version_ | 1828365238078013440 |
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| author | Alexis N. Moyer Peter W. Nienow Noel Gourmelen Noel Gourmelen Andrew J. Sole Donald A. Slater Donald A. Slater |
| author_facet | Alexis N. Moyer Peter W. Nienow Noel Gourmelen Noel Gourmelen Andrew J. Sole Donald A. Slater Donald A. Slater |
| author_sort | Alexis N. Moyer |
| collection | DOAJ |
| description | Oceanic forcing of the Greenland Ice Sheet is believed to promote widespread thinning at tidewater glaciers, with submarine melting proposed as a potential trigger of increased glacier calving, retreat, and subsequent acceleration. The precise mechanism(s) driving glacier instability, however, remain poorly understood, and while increasing evidence points to the importance of submarine melting, estimates of melt rates are uncertain. Here we estimate submarine melt rate by examining freeboard changes in the seasonal ice tongue of Kangiata Nunaata Sermia (KNS) at the head of Kangersuneq Fjord (KF), southwest Greenland. We calculate melt rates for March and May 2013 by differencing along-fjord surface elevation, derived from high-resolution TanDEM-X digital elevation models (DEMs), in combination with ice velocities derived from offset tracking applied to TerraSAR-X imagery. Estimated steady state melt rates reach up to 1.4 ± 0.5 m d−1 near the glacier grounding line, with mean values of up to 0.8 ± 0.3 and 0.7 ± 0.3 m d−1 for the eastern and western parts of the ice tongue, respectively. Melt rates decrease with distance from the ice front and vary across the fjord. This methodology reveals spatio-temporal variations in submarine melt rates (SMRs) at tidewater glaciers which develop floating termini, and can be used to improve our understanding of ice-ocean interactions and submarine melting in glacial fjords. |
| first_indexed | 2024-04-14T05:28:18Z |
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| id | doaj.art-7bcd47a0637f48acb2a98914236b8ee8 |
| institution | Directory Open Access Journal |
| issn | 2296-6463 |
| language | English |
| last_indexed | 2024-04-14T05:28:18Z |
| publishDate | 2017-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Earth Science |
| spelling | doaj.art-7bcd47a0637f48acb2a98914236b8ee82022-12-22T02:09:55ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632017-12-01510.3389/feart.2017.00107306789Estimating Spring Terminus Submarine Melt Rates at a Greenlandic Tidewater Glacier Using Satellite ImageryAlexis N. Moyer0Peter W. Nienow1Noel Gourmelen2Noel Gourmelen3Andrew J. Sole4Donald A. Slater5Donald A. Slater6School of Geosciences, University of Edinburgh, Edinburgh, United KingdomSchool of Geosciences, University of Edinburgh, Edinburgh, United KingdomSchool of Geosciences, University of Edinburgh, Edinburgh, United KingdomIPGS UMR 7516, Université de Strasbourg, CNRS, Strasbourg, FranceDepartment of Geography, University of Sheffield, Sheffield, United KingdomSchool of Geosciences, University of Edinburgh, Edinburgh, United KingdomScripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, United StatesOceanic forcing of the Greenland Ice Sheet is believed to promote widespread thinning at tidewater glaciers, with submarine melting proposed as a potential trigger of increased glacier calving, retreat, and subsequent acceleration. The precise mechanism(s) driving glacier instability, however, remain poorly understood, and while increasing evidence points to the importance of submarine melting, estimates of melt rates are uncertain. Here we estimate submarine melt rate by examining freeboard changes in the seasonal ice tongue of Kangiata Nunaata Sermia (KNS) at the head of Kangersuneq Fjord (KF), southwest Greenland. We calculate melt rates for March and May 2013 by differencing along-fjord surface elevation, derived from high-resolution TanDEM-X digital elevation models (DEMs), in combination with ice velocities derived from offset tracking applied to TerraSAR-X imagery. Estimated steady state melt rates reach up to 1.4 ± 0.5 m d−1 near the glacier grounding line, with mean values of up to 0.8 ± 0.3 and 0.7 ± 0.3 m d−1 for the eastern and western parts of the ice tongue, respectively. Melt rates decrease with distance from the ice front and vary across the fjord. This methodology reveals spatio-temporal variations in submarine melt rates (SMRs) at tidewater glaciers which develop floating termini, and can be used to improve our understanding of ice-ocean interactions and submarine melting in glacial fjords.http://journal.frontiersin.org/article/10.3389/feart.2017.00107/fullsubmarine meltice/ocean interactionstidewater glaciersremote sensingTanDEM-X |
| spellingShingle | Alexis N. Moyer Peter W. Nienow Noel Gourmelen Noel Gourmelen Andrew J. Sole Donald A. Slater Donald A. Slater Estimating Spring Terminus Submarine Melt Rates at a Greenlandic Tidewater Glacier Using Satellite Imagery Frontiers in Earth Science submarine melt ice/ocean interactions tidewater glaciers remote sensing TanDEM-X |
| title | Estimating Spring Terminus Submarine Melt Rates at a Greenlandic Tidewater Glacier Using Satellite Imagery |
| title_full | Estimating Spring Terminus Submarine Melt Rates at a Greenlandic Tidewater Glacier Using Satellite Imagery |
| title_fullStr | Estimating Spring Terminus Submarine Melt Rates at a Greenlandic Tidewater Glacier Using Satellite Imagery |
| title_full_unstemmed | Estimating Spring Terminus Submarine Melt Rates at a Greenlandic Tidewater Glacier Using Satellite Imagery |
| title_short | Estimating Spring Terminus Submarine Melt Rates at a Greenlandic Tidewater Glacier Using Satellite Imagery |
| title_sort | estimating spring terminus submarine melt rates at a greenlandic tidewater glacier using satellite imagery |
| topic | submarine melt ice/ocean interactions tidewater glaciers remote sensing TanDEM-X |
| url | http://journal.frontiersin.org/article/10.3389/feart.2017.00107/full |
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