Rapid Iceberg Calving Following Removal of Tightly Packed Pro-Glacial Mélange at Jakobshavn Isbræ, Greenland
Iceberg calving is a major contributor to Greenland’s ice mass loss and to sea level rise. Pro-glacial mélange (compressed ice fragments) may be tightly packed in the long, narrow fjords that front many marine-terminating glaciers and can reduce calving by buttressing. The effect is important for mo...
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ftusouthflorida:oai:digitalcommons.usf.edu:geo_facpub-3046 2023-07-30T04:03:36+02:00 Rapid Iceberg Calving Following Removal of Tightly Packed Pro-Glacial Mélange at Jakobshavn Isbræ, Greenland Xie, Surui Dixon, Timothy H. Holland, David M. Voytenko, Denis Vaňková, Irena 2018-12-11T08:00:00Z https://digitalcommons.usf.edu/geo_facpub/2062 https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/443573 unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/geo_facpub/2062 https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/443573 School of Geosciences Faculty and Staff Publications Earth Sciences presentation 2018 ftusouthflorida 2023-07-13T20:45:47Z Iceberg calving is a major contributor to Greenland’s ice mass loss and to sea level rise. Pro-glacial mélange (compressed ice fragments) may be tightly packed in the long, narrow fjords that front many marine-terminating glaciers and can reduce calving by buttressing. The effect is important for modeling glacier dynamics in Greenland. However, data limitations have hampered a quantitative understanding. We describe a new radar-based approach to map time-varying elevations near the mélange-glacier interface that provides a factor of three or more improvement in precision, and apply the technique to the terminus of Jakobshavn Isbræ, a major Greenland outlet glacier. The new data allow mélange changes to be quantified with high spatial and temporal resolution. Over a one-month period from late May to late June 2016, the glacier experienced essentially no major calving, and was buttressed by a thick mélange wedge. Large-scale calving began once mélange mass within 7 km of the glacier front decreased by >40%. And the total buttressing force decreased by ~1 × 107 N m-1 (the unit is force per meter lateral width) during a 13 day period with continuous observations by a terrestrial radar interferometer. To our knowledge, these are the first observations of a near-field, time-varying pro-glacial mélange wedge. The observations provide direct evidence that tightly-packed mélange reduces calving, and place quantitative constraints on the process. Conference Object glacier Greenland Jakobshavn Jakobshavn isbræ University of South Florida St. Petersburg: Digital USFSP Greenland Jakobshavn Isbræ ENVELOPE(-49.917,-49.917,69.167,69.167) |
institution |
Open Polar |
collection |
University of South Florida St. Petersburg: Digital USFSP |
op_collection_id |
ftusouthflorida |
language |
unknown |
topic |
Earth Sciences |
spellingShingle |
Earth Sciences Xie, Surui Dixon, Timothy H. Holland, David M. Voytenko, Denis Vaňková, Irena Rapid Iceberg Calving Following Removal of Tightly Packed Pro-Glacial Mélange at Jakobshavn Isbræ, Greenland |
topic_facet |
Earth Sciences |
description |
Iceberg calving is a major contributor to Greenland’s ice mass loss and to sea level rise. Pro-glacial mélange (compressed ice fragments) may be tightly packed in the long, narrow fjords that front many marine-terminating glaciers and can reduce calving by buttressing. The effect is important for modeling glacier dynamics in Greenland. However, data limitations have hampered a quantitative understanding. We describe a new radar-based approach to map time-varying elevations near the mélange-glacier interface that provides a factor of three or more improvement in precision, and apply the technique to the terminus of Jakobshavn Isbræ, a major Greenland outlet glacier. The new data allow mélange changes to be quantified with high spatial and temporal resolution. Over a one-month period from late May to late June 2016, the glacier experienced essentially no major calving, and was buttressed by a thick mélange wedge. Large-scale calving began once mélange mass within 7 km of the glacier front decreased by >40%. And the total buttressing force decreased by ~1 × 107 N m-1 (the unit is force per meter lateral width) during a 13 day period with continuous observations by a terrestrial radar interferometer. To our knowledge, these are the first observations of a near-field, time-varying pro-glacial mélange wedge. The observations provide direct evidence that tightly-packed mélange reduces calving, and place quantitative constraints on the process. |
format |
Conference Object |
author |
Xie, Surui Dixon, Timothy H. Holland, David M. Voytenko, Denis Vaňková, Irena |
author_facet |
Xie, Surui Dixon, Timothy H. Holland, David M. Voytenko, Denis Vaňková, Irena |
author_sort |
Xie, Surui |
title |
Rapid Iceberg Calving Following Removal of Tightly Packed Pro-Glacial Mélange at Jakobshavn Isbræ, Greenland |
title_short |
Rapid Iceberg Calving Following Removal of Tightly Packed Pro-Glacial Mélange at Jakobshavn Isbræ, Greenland |
title_full |
Rapid Iceberg Calving Following Removal of Tightly Packed Pro-Glacial Mélange at Jakobshavn Isbræ, Greenland |
title_fullStr |
Rapid Iceberg Calving Following Removal of Tightly Packed Pro-Glacial Mélange at Jakobshavn Isbræ, Greenland |
title_full_unstemmed |
Rapid Iceberg Calving Following Removal of Tightly Packed Pro-Glacial Mélange at Jakobshavn Isbræ, Greenland |
title_sort |
rapid iceberg calving following removal of tightly packed pro-glacial mélange at jakobshavn isbræ, greenland |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2018 |
url |
https://digitalcommons.usf.edu/geo_facpub/2062 https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/443573 |
long_lat |
ENVELOPE(-49.917,-49.917,69.167,69.167) |
geographic |
Greenland Jakobshavn Isbræ |
geographic_facet |
Greenland Jakobshavn Isbræ |
genre |
glacier Greenland Jakobshavn Jakobshavn isbræ |
genre_facet |
glacier Greenland Jakobshavn Jakobshavn isbræ |
op_source |
School of Geosciences Faculty and Staff Publications |
op_relation |
https://digitalcommons.usf.edu/geo_facpub/2062 https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/443573 |
_version_ |
1772814635192287232 |