A large impact crater beneath Hiawatha Glacier in northwest Greenland.
We report the discovery of a large impact crater beneath Hiawatha Glacier in northwest Greenland. From airborne radar surveys, we identify a 31-kilometer-wide, circular bedrock depression beneath up to a kilometer of ice. This depression has an elevated rim that cross-cuts tributary subglacial chann...
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ftcdlib:oai:escholarship.org/ark:/13030/qt5820j274 2023-05-15T16:21:07+02:00 A large impact crater beneath Hiawatha Glacier in northwest Greenland. Kjær, Kurt H Larsen, Nicolaj K Binder, Tobias Bjørk, Anders A Eisen, Olaf Fahnestock, Mark A Funder, Svend Garde, Adam A Haack, Henning Helm, Veit Houmark-Nielsen, Michael Kjeldsen, Kristian K Khan, Shfaqat A Machguth, Horst McDonald, Iain Morlighem, Mathieu Mouginot, Jérémie Paden, John D Waight, Tod E Weikusat, Christian Willerslev, Eske MacGregor, Joseph A eaar8173 2018-11-14 application/pdf https://escholarship.org/uc/item/5820j274 unknown eScholarship, University of California qt5820j274 https://escholarship.org/uc/item/5820j274 CC-BY CC-BY Science advances, vol 4, iss 11 article 2018 ftcdlib 2020-08-18T09:20:11Z We report the discovery of a large impact crater beneath Hiawatha Glacier in northwest Greenland. From airborne radar surveys, we identify a 31-kilometer-wide, circular bedrock depression beneath up to a kilometer of ice. This depression has an elevated rim that cross-cuts tributary subglacial channels and a subdued central uplift that appears to be actively eroding. From ground investigations of the deglaciated foreland, we identify overprinted structures within Precambrian bedrock along the ice margin that strike tangent to the subglacial rim. Glaciofluvial sediment from the largest river draining the crater contains shocked quartz and other impact-related grains. Geochemical analysis of this sediment indicates that the impactor was a fractionated iron asteroid, which must have been more than a kilometer wide to produce the identified crater. Radiostratigraphy of the ice in the crater shows that the Holocene ice is continuous and conformable, but all deeper and older ice appears to be debris rich or heavily disturbed. The age of this impact crater is presently unknown, but from our geological and geophysical evidence, we conclude that it is unlikely to predate the Pleistocene inception of the Greenland Ice Sheet. Article in Journal/Newspaper glacier Greenland Ice Sheet University of California: eScholarship Greenland |
institution |
Open Polar |
collection |
University of California: eScholarship |
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ftcdlib |
language |
unknown |
description |
We report the discovery of a large impact crater beneath Hiawatha Glacier in northwest Greenland. From airborne radar surveys, we identify a 31-kilometer-wide, circular bedrock depression beneath up to a kilometer of ice. This depression has an elevated rim that cross-cuts tributary subglacial channels and a subdued central uplift that appears to be actively eroding. From ground investigations of the deglaciated foreland, we identify overprinted structures within Precambrian bedrock along the ice margin that strike tangent to the subglacial rim. Glaciofluvial sediment from the largest river draining the crater contains shocked quartz and other impact-related grains. Geochemical analysis of this sediment indicates that the impactor was a fractionated iron asteroid, which must have been more than a kilometer wide to produce the identified crater. Radiostratigraphy of the ice in the crater shows that the Holocene ice is continuous and conformable, but all deeper and older ice appears to be debris rich or heavily disturbed. The age of this impact crater is presently unknown, but from our geological and geophysical evidence, we conclude that it is unlikely to predate the Pleistocene inception of the Greenland Ice Sheet. |
format |
Article in Journal/Newspaper |
author |
Kjær, Kurt H Larsen, Nicolaj K Binder, Tobias Bjørk, Anders A Eisen, Olaf Fahnestock, Mark A Funder, Svend Garde, Adam A Haack, Henning Helm, Veit Houmark-Nielsen, Michael Kjeldsen, Kristian K Khan, Shfaqat A Machguth, Horst McDonald, Iain Morlighem, Mathieu Mouginot, Jérémie Paden, John D Waight, Tod E Weikusat, Christian Willerslev, Eske MacGregor, Joseph A |
spellingShingle |
Kjær, Kurt H Larsen, Nicolaj K Binder, Tobias Bjørk, Anders A Eisen, Olaf Fahnestock, Mark A Funder, Svend Garde, Adam A Haack, Henning Helm, Veit Houmark-Nielsen, Michael Kjeldsen, Kristian K Khan, Shfaqat A Machguth, Horst McDonald, Iain Morlighem, Mathieu Mouginot, Jérémie Paden, John D Waight, Tod E Weikusat, Christian Willerslev, Eske MacGregor, Joseph A A large impact crater beneath Hiawatha Glacier in northwest Greenland. |
author_facet |
Kjær, Kurt H Larsen, Nicolaj K Binder, Tobias Bjørk, Anders A Eisen, Olaf Fahnestock, Mark A Funder, Svend Garde, Adam A Haack, Henning Helm, Veit Houmark-Nielsen, Michael Kjeldsen, Kristian K Khan, Shfaqat A Machguth, Horst McDonald, Iain Morlighem, Mathieu Mouginot, Jérémie Paden, John D Waight, Tod E Weikusat, Christian Willerslev, Eske MacGregor, Joseph A |
author_sort |
Kjær, Kurt H |
title |
A large impact crater beneath Hiawatha Glacier in northwest Greenland. |
title_short |
A large impact crater beneath Hiawatha Glacier in northwest Greenland. |
title_full |
A large impact crater beneath Hiawatha Glacier in northwest Greenland. |
title_fullStr |
A large impact crater beneath Hiawatha Glacier in northwest Greenland. |
title_full_unstemmed |
A large impact crater beneath Hiawatha Glacier in northwest Greenland. |
title_sort |
large impact crater beneath hiawatha glacier in northwest greenland. |
publisher |
eScholarship, University of California |
publishDate |
2018 |
url |
https://escholarship.org/uc/item/5820j274 |
op_coverage |
eaar8173 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
glacier Greenland Ice Sheet |
genre_facet |
glacier Greenland Ice Sheet |
op_source |
Science advances, vol 4, iss 11 |
op_relation |
qt5820j274 https://escholarship.org/uc/item/5820j274 |
op_rights |
CC-BY |
op_rightsnorm |
CC-BY |
_version_ |
1766009128491155456 |