Late-Glacial and Holocene Relative Sea-Level Change, Scoresby Sund, East Greenland
The age of the Milne Land Stade (MLS) moraines in East Greenland is key for testing the hypothesis that abrupt cooling events seen in Greenland ice cores are characterized by extreme seasonality. In recent papers, the moraines have been assumed to be of Younger Dryas age, allowing direct comparison...
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American Geophysical Union
2007
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ftunivpisairis:oai:arpi.unipi.it:11568/646075 2024-04-14T08:11:01+00:00 Late-Glacial and Holocene Relative Sea-Level Change, Scoresby Sund, East Greenland Hall B. L. Denton G. H. Kelly M. Lowell T. W. BARONI, CARLO AGU Hall, B. L. Baroni, Carlo Denton, G. H. Kelly, M. Lowell, T. W. 2007 ELETTRONICO http://hdl.handle.net/11568/646075 http://abstractsearch.agu.org/meetings/2007/FM/sections/C/sessions/C11A/abstracts/C11A-0070.html eng eng American Geophysical Union country:USA place:Washington ispartofbook:Fall Meeting 2007 AGU Fall Meeting volume:88 issue:52 firstpage:1 lastpage:1 numberofpages:1 journal:EOS, TRANSACTIONS http://hdl.handle.net/11568/646075 http://abstractsearch.agu.org/meetings/2007/FM/sections/C/sessions/C11A/abstracts/C11A-0070.html Ice sheet Quaternary geochronology Abrupt/rapid climate change Greenland info:eu-repo/semantics/conferenceObject 2007 ftunivpisairis 2024-03-21T18:45:09Z The age of the Milne Land Stade (MLS) moraines in East Greenland is key for testing the hypothesis that abrupt cooling events seen in Greenland ice cores are characterized by extreme seasonality. In recent papers, the moraines have been assumed to be of Younger Dryas age, allowing direct comparison of snowline lowering estimates with coeval temperature depressions from the nearby ice cores. It is a mismatch of as much as 10 degrees C between these two climate proxies that led to the idea of extreme seasonality. Thus, accurately determining the age of the moraines is a prerequisite to testing this hypothesis. In the Scoresby Sund region, retreat from the MLS moraines was accompanied by marine inundation and isostatic rebound. Here, we present more than 150 radiocarbon dates of shells in raised beaches and deltas from Kjove Land and nearby Schuchert Dal that formed after deglaciation from adjacent MLS moraines. Together, these samples are the basis for two curves, each of which shows very high rates of relative sea-level change typical of recently deglaciated regions. The curves are similar, with both indicating total uplift (including areas now drowned by rising sea level) of slightly less than 200 m. The marine limit (134 m) dates to 12,200 cal yr B.P. We suggest that this is a close minimum age for moraine formation and indicates that the outer MLS moraines likely date to earliest Younger Dryas time. The younger, inner moraine set grades to a former sea level, now at 101 m elevation, and dates to 10,600-10,900 cal yr B.P. The Younger Dryas age for the older set is consistent with the idea that there was extreme seasonality in Greenland during late-glacial time. Conference Object East Greenland Greenland Greenland ice cores Ice Sheet Milne Land Scoresby Sund ARPI - Archivio della Ricerca dell'Università di Pisa Greenland Sund ENVELOPE(13.644,13.644,66.207,66.207) Scoresby ENVELOPE(162.750,162.750,-66.567,-66.567) Scoresby Sund ENVELOPE(-24.387,-24.387,70.476,70.476) Milne Land ENVELOPE(-26.750,-26.750,70.683,70.683) |
institution |
Open Polar |
collection |
ARPI - Archivio della Ricerca dell'Università di Pisa |
op_collection_id |
ftunivpisairis |
language |
English |
topic |
Ice sheet Quaternary geochronology Abrupt/rapid climate change Greenland |
spellingShingle |
Ice sheet Quaternary geochronology Abrupt/rapid climate change Greenland Hall B. L. Denton G. H. Kelly M. Lowell T. W. BARONI, CARLO Late-Glacial and Holocene Relative Sea-Level Change, Scoresby Sund, East Greenland |
topic_facet |
Ice sheet Quaternary geochronology Abrupt/rapid climate change Greenland |
description |
The age of the Milne Land Stade (MLS) moraines in East Greenland is key for testing the hypothesis that abrupt cooling events seen in Greenland ice cores are characterized by extreme seasonality. In recent papers, the moraines have been assumed to be of Younger Dryas age, allowing direct comparison of snowline lowering estimates with coeval temperature depressions from the nearby ice cores. It is a mismatch of as much as 10 degrees C between these two climate proxies that led to the idea of extreme seasonality. Thus, accurately determining the age of the moraines is a prerequisite to testing this hypothesis. In the Scoresby Sund region, retreat from the MLS moraines was accompanied by marine inundation and isostatic rebound. Here, we present more than 150 radiocarbon dates of shells in raised beaches and deltas from Kjove Land and nearby Schuchert Dal that formed after deglaciation from adjacent MLS moraines. Together, these samples are the basis for two curves, each of which shows very high rates of relative sea-level change typical of recently deglaciated regions. The curves are similar, with both indicating total uplift (including areas now drowned by rising sea level) of slightly less than 200 m. The marine limit (134 m) dates to 12,200 cal yr B.P. We suggest that this is a close minimum age for moraine formation and indicates that the outer MLS moraines likely date to earliest Younger Dryas time. The younger, inner moraine set grades to a former sea level, now at 101 m elevation, and dates to 10,600-10,900 cal yr B.P. The Younger Dryas age for the older set is consistent with the idea that there was extreme seasonality in Greenland during late-glacial time. |
author2 |
AGU Hall, B. L. Baroni, Carlo Denton, G. H. Kelly, M. Lowell, T. W. |
format |
Conference Object |
author |
Hall B. L. Denton G. H. Kelly M. Lowell T. W. BARONI, CARLO |
author_facet |
Hall B. L. Denton G. H. Kelly M. Lowell T. W. BARONI, CARLO |
author_sort |
Hall B. L. |
title |
Late-Glacial and Holocene Relative Sea-Level Change, Scoresby Sund, East Greenland |
title_short |
Late-Glacial and Holocene Relative Sea-Level Change, Scoresby Sund, East Greenland |
title_full |
Late-Glacial and Holocene Relative Sea-Level Change, Scoresby Sund, East Greenland |
title_fullStr |
Late-Glacial and Holocene Relative Sea-Level Change, Scoresby Sund, East Greenland |
title_full_unstemmed |
Late-Glacial and Holocene Relative Sea-Level Change, Scoresby Sund, East Greenland |
title_sort |
late-glacial and holocene relative sea-level change, scoresby sund, east greenland |
publisher |
American Geophysical Union |
publishDate |
2007 |
url |
http://hdl.handle.net/11568/646075 http://abstractsearch.agu.org/meetings/2007/FM/sections/C/sessions/C11A/abstracts/C11A-0070.html |
long_lat |
ENVELOPE(13.644,13.644,66.207,66.207) ENVELOPE(162.750,162.750,-66.567,-66.567) ENVELOPE(-24.387,-24.387,70.476,70.476) ENVELOPE(-26.750,-26.750,70.683,70.683) |
geographic |
Greenland Sund Scoresby Scoresby Sund Milne Land |
geographic_facet |
Greenland Sund Scoresby Scoresby Sund Milne Land |
genre |
East Greenland Greenland Greenland ice cores Ice Sheet Milne Land Scoresby Sund |
genre_facet |
East Greenland Greenland Greenland ice cores Ice Sheet Milne Land Scoresby Sund |
op_relation |
ispartofbook:Fall Meeting 2007 AGU Fall Meeting volume:88 issue:52 firstpage:1 lastpage:1 numberofpages:1 journal:EOS, TRANSACTIONS http://hdl.handle.net/11568/646075 http://abstractsearch.agu.org/meetings/2007/FM/sections/C/sessions/C11A/abstracts/C11A-0070.html |
_version_ |
1796308681032204288 |