Glacial erosion: No stones unturned?
Is erosion of landscape under ice sheets significant or negligible? In the Arctic, it seems, it is both. I show evidence for cold-based margins of Greenland ice during the Last Glacial Maximum and for warm-based center at an unspecified time in the past. Take a walk through Nyeboe Land, in the north...
Main Author: | |
---|---|
Other Authors: | |
Format: | Text |
Language: | English |
Subjects: | |
Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.495.8875 http://quebec.hwr.arizona.edu/research/egu05-zreda-glacial-erosion.pdf |
id |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.495.8875 |
---|---|
record_format |
openpolar |
spelling |
ftciteseerx:oai:CiteSeerX.psu:10.1.1.495.8875 2023-05-15T15:07:46+02:00 Glacial erosion: No stones unturned? M. Zreda The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.495.8875 http://quebec.hwr.arizona.edu/research/egu05-zreda-glacial-erosion.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.495.8875 http://quebec.hwr.arizona.edu/research/egu05-zreda-glacial-erosion.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://quebec.hwr.arizona.edu/research/egu05-zreda-glacial-erosion.pdf text ftciteseerx 2016-01-08T08:46:17Z Is erosion of landscape under ice sheets significant or negligible? In the Arctic, it seems, it is both. I show evidence for cold-based margins of Greenland ice during the Last Glacial Maximum and for warm-based center at an unspecified time in the past. Take a walk through Nyeboe Land, in the northwestern Greenland, and, as your feet sink in the soft till, your eyes are drawn to the mountains across the Nares Strait or to the margin of the Greenland ice sheet. But one of the most remarkable features in this landscape is one of the easiest to overlook – that this surface has two generations of erratics deposited at two different times. These erratics were dated by cosmogenic 36Cl. One group of boulders, exclusively red granites, was deposited 27±2 ky ago (ky = 1000 years); the other, exclusively gray limestones, was deposited 8±1 ky ago. The small spread of individual boulder ages strongly suggests that these erratics have remained in the same position since their deposition. And the age difference suggests that there were two ice-sheet advances: the first involved a large, regional ice and wide dispersal of granitic erratics from the interior of Greenland; the second glaciation was smaller and dispersed material from the local bedrock. The Text Arctic Greenland Ice Sheet Nares strait Nyeboe land Unknown Arctic Greenland Nares ENVELOPE(158.167,158.167,-81.450,-81.450) Nyeboe Land ENVELOPE(-56.750,-56.750,81.900,81.900) |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
ftciteseerx |
language |
English |
description |
Is erosion of landscape under ice sheets significant or negligible? In the Arctic, it seems, it is both. I show evidence for cold-based margins of Greenland ice during the Last Glacial Maximum and for warm-based center at an unspecified time in the past. Take a walk through Nyeboe Land, in the northwestern Greenland, and, as your feet sink in the soft till, your eyes are drawn to the mountains across the Nares Strait or to the margin of the Greenland ice sheet. But one of the most remarkable features in this landscape is one of the easiest to overlook – that this surface has two generations of erratics deposited at two different times. These erratics were dated by cosmogenic 36Cl. One group of boulders, exclusively red granites, was deposited 27±2 ky ago (ky = 1000 years); the other, exclusively gray limestones, was deposited 8±1 ky ago. The small spread of individual boulder ages strongly suggests that these erratics have remained in the same position since their deposition. And the age difference suggests that there were two ice-sheet advances: the first involved a large, regional ice and wide dispersal of granitic erratics from the interior of Greenland; the second glaciation was smaller and dispersed material from the local bedrock. The |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
M. Zreda |
spellingShingle |
M. Zreda Glacial erosion: No stones unturned? |
author_facet |
M. Zreda |
author_sort |
M. Zreda |
title |
Glacial erosion: No stones unturned? |
title_short |
Glacial erosion: No stones unturned? |
title_full |
Glacial erosion: No stones unturned? |
title_fullStr |
Glacial erosion: No stones unturned? |
title_full_unstemmed |
Glacial erosion: No stones unturned? |
title_sort |
glacial erosion: no stones unturned? |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.495.8875 http://quebec.hwr.arizona.edu/research/egu05-zreda-glacial-erosion.pdf |
long_lat |
ENVELOPE(158.167,158.167,-81.450,-81.450) ENVELOPE(-56.750,-56.750,81.900,81.900) |
geographic |
Arctic Greenland Nares Nyeboe Land |
geographic_facet |
Arctic Greenland Nares Nyeboe Land |
genre |
Arctic Greenland Ice Sheet Nares strait Nyeboe land |
genre_facet |
Arctic Greenland Ice Sheet Nares strait Nyeboe land |
op_source |
http://quebec.hwr.arizona.edu/research/egu05-zreda-glacial-erosion.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.495.8875 http://quebec.hwr.arizona.edu/research/egu05-zreda-glacial-erosion.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766339197311909888 |