Bathymetry in Petermann fjord from Operation IceBridge aerogravity
Petermann Glacier is a major glacier in northern Greenland, maintaining one of the few remaining floating ice tongues in Greenland. Monitoring programs, such as NASA’s Operation IceBridge have surveyed Petermann Glacier over several decades and have found it to be stable in terms of mass balance, ve...
Main Authors: | , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2015
|
Subjects: | |
Online Access: | https://doi.org/10.7916/d8-2dct-4293 |
id |
ftcolumbiauniv:oai:academiccommons.columbia.edu:10.7916/d8-2dct-4293 |
---|---|
record_format |
openpolar |
spelling |
ftcolumbiauniv:oai:academiccommons.columbia.edu:10.7916/d8-2dct-4293 2023-05-15T16:21:06+02:00 Bathymetry in Petermann fjord from Operation IceBridge aerogravity Tinto, Kirsteen J. Bell, Robin E. Cochran, James R. Munchow, Andreas 2015 https://doi.org/10.7916/d8-2dct-4293 English eng https://doi.org/10.7916/d8-2dct-4293 Geophysics Marine geophysics Glaciers--Measurement Fjords Bathymetric maps Articles 2015 ftcolumbiauniv https://doi.org/10.7916/d8-2dct-4293 2019-07-06T22:19:53Z Petermann Glacier is a major glacier in northern Greenland, maintaining one of the few remaining floating ice tongues in Greenland. Monitoring programs, such as NASA’s Operation IceBridge have surveyed Petermann Glacier over several decades and have found it to be stable in terms of mass balance, velocity and grounding-line position. The future vulnerability of this large glacier to changing ocean temperatures and climate depends on the ocean–ice interactions beneath its floating tongue. These cannot currently be predicted due to a lack of knowledge of the bathymetry underneath the ice tongue. Here we use aerogravity data from Operation IceBridge, together with airborne radar and laser data and shipborne bathymetry-soundings to model the bathymetry beneath the Petermann ice tongue. We find a basement-cored inner sill at 540–610 m depth that results in a water cavity with minimum thickness of 400 m about 25 km from the grounding line. The sill is coincident with the location of the melt rate minimum. Seaward of the sill the fjord is strongly asymmetric. The deepest point occurs on the eastern side of the fjord at 1150 m, 600 m deeper than on the western side. This asymmetry is due to a sedimentary deposit on the western side of the fjord. A 350–410 m-deep outer sill, also mapped by marine surveys, marks the seaward end of the fjord. This outer sill is aligned with the proposed Last Glacial Maximum (LGM) grounding-line position for Petermann Glacier. The inner sill likely provided a stable pinning point for the grounding line in the past, punctuating the retreat of Petermann Glacier since the LGM. Article in Journal/Newspaper glacier Greenland Petermann Fjord Petermann glacier Columbia University: Academic Commons Greenland Petermann Fjord ENVELOPE(-61.500,-61.500,81.167,81.167) |
institution |
Open Polar |
collection |
Columbia University: Academic Commons |
op_collection_id |
ftcolumbiauniv |
language |
English |
topic |
Geophysics Marine geophysics Glaciers--Measurement Fjords Bathymetric maps |
spellingShingle |
Geophysics Marine geophysics Glaciers--Measurement Fjords Bathymetric maps Tinto, Kirsteen J. Bell, Robin E. Cochran, James R. Munchow, Andreas Bathymetry in Petermann fjord from Operation IceBridge aerogravity |
topic_facet |
Geophysics Marine geophysics Glaciers--Measurement Fjords Bathymetric maps |
description |
Petermann Glacier is a major glacier in northern Greenland, maintaining one of the few remaining floating ice tongues in Greenland. Monitoring programs, such as NASA’s Operation IceBridge have surveyed Petermann Glacier over several decades and have found it to be stable in terms of mass balance, velocity and grounding-line position. The future vulnerability of this large glacier to changing ocean temperatures and climate depends on the ocean–ice interactions beneath its floating tongue. These cannot currently be predicted due to a lack of knowledge of the bathymetry underneath the ice tongue. Here we use aerogravity data from Operation IceBridge, together with airborne radar and laser data and shipborne bathymetry-soundings to model the bathymetry beneath the Petermann ice tongue. We find a basement-cored inner sill at 540–610 m depth that results in a water cavity with minimum thickness of 400 m about 25 km from the grounding line. The sill is coincident with the location of the melt rate minimum. Seaward of the sill the fjord is strongly asymmetric. The deepest point occurs on the eastern side of the fjord at 1150 m, 600 m deeper than on the western side. This asymmetry is due to a sedimentary deposit on the western side of the fjord. A 350–410 m-deep outer sill, also mapped by marine surveys, marks the seaward end of the fjord. This outer sill is aligned with the proposed Last Glacial Maximum (LGM) grounding-line position for Petermann Glacier. The inner sill likely provided a stable pinning point for the grounding line in the past, punctuating the retreat of Petermann Glacier since the LGM. |
format |
Article in Journal/Newspaper |
author |
Tinto, Kirsteen J. Bell, Robin E. Cochran, James R. Munchow, Andreas |
author_facet |
Tinto, Kirsteen J. Bell, Robin E. Cochran, James R. Munchow, Andreas |
author_sort |
Tinto, Kirsteen J. |
title |
Bathymetry in Petermann fjord from Operation IceBridge aerogravity |
title_short |
Bathymetry in Petermann fjord from Operation IceBridge aerogravity |
title_full |
Bathymetry in Petermann fjord from Operation IceBridge aerogravity |
title_fullStr |
Bathymetry in Petermann fjord from Operation IceBridge aerogravity |
title_full_unstemmed |
Bathymetry in Petermann fjord from Operation IceBridge aerogravity |
title_sort |
bathymetry in petermann fjord from operation icebridge aerogravity |
publishDate |
2015 |
url |
https://doi.org/10.7916/d8-2dct-4293 |
long_lat |
ENVELOPE(-61.500,-61.500,81.167,81.167) |
geographic |
Greenland Petermann Fjord |
geographic_facet |
Greenland Petermann Fjord |
genre |
glacier Greenland Petermann Fjord Petermann glacier |
genre_facet |
glacier Greenland Petermann Fjord Petermann glacier |
op_relation |
https://doi.org/10.7916/d8-2dct-4293 |
op_doi |
https://doi.org/10.7916/d8-2dct-4293 |
_version_ |
1766009110561554432 |