Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica
Inversion of NASA Operation IceBridge airborne gravity over the Abbot Ice Shelf in West Antarctica for subice bathymetry defines an extensional terrain made up of east-west trending rift basins formed during the early stages of Antarctica/Zealandia rifting. Extension is minor, as rifting jumped nort...
Main Authors: | , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
2015
|
Subjects: | |
Online Access: | https://doi.org/10.7916/d8-66p2-2s41 |
id |
ftcolumbiauniv:oai:academiccommons.columbia.edu:10.7916/d8-66p2-2s41 |
---|---|
record_format |
openpolar |
spelling |
ftcolumbiauniv:oai:academiccommons.columbia.edu:10.7916/d8-66p2-2s41 2023-05-15T12:58:34+02:00 Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica Cochran, James R. Tinto, Kirsteen J. Bell, Robin E. 2015 https://doi.org/10.7916/d8-66p2-2s41 English eng https://doi.org/10.7916/d8-66p2-2s41 Geophysics Ice shelves Geomorphology Continental margins Bathymetric maps Articles 2015 ftcolumbiauniv https://doi.org/10.7916/d8-66p2-2s41 2019-06-29T22:19:36Z Inversion of NASA Operation IceBridge airborne gravity over the Abbot Ice Shelf in West Antarctica for subice bathymetry defines an extensional terrain made up of east-west trending rift basins formed during the early stages of Antarctica/Zealandia rifting. Extension is minor, as rifting jumped north of Thurston Island early in the rifting process. The Amundsen Sea Embayment continental shelf west of the rifted terrain is underlain by a deeper, more extensive sedimentary basin also formed during rifting between Antarctica and Zealandia. A well-defined boundary zone separates the mildly extended Abbot extensional terrain from the deeper Amundsen Embayment shelf basin. The shelf basin has an extension factor, b, of 1.5–1.7 with 80–100 km of extension occurring across an area now 250 km wide. Following this extension, rifting centered north of the present shelf edge and proceeded to continental rupture. Since then, the Amundsen Embayment continental shelf appears to have been tectonically quiescent and shaped by subsidence, sedimentation, and the advance and retreat of the West Antarctic Ice Sheet. The Bellingshausen Plate was located seaward of the Amundsen Sea margin prior to incorporation into the Antarctic Plate at about 62 Ma. During the latter part of its independent existence, Bellingshausen plate motion had a clockwise rotational component relative to Antarctica producing convergence across the north-south trending Bellingshausen Gravity Anomaly structure at 94°W and compressive deformation on the continental slope between 94°W and 102°W. Farther west, the relative motion was extensional along an east-west trending zone occupied by the Marie Byrd Seamounts. Article in Journal/Newspaper Abbot Ice Shelf Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Thurston Island West Antarctica Columbia University: Academic Commons Abbot Ice Shelf ENVELOPE(-96.000,-96.000,-72.750,-72.750) Amundsen Sea Antarctic Byrd The Antarctic Thurston ENVELOPE(-97.500,-97.500,-71.833,-71.833) Thurston Island ENVELOPE(-99.000,-99.000,-72.167,-72.167) West Antarctic Ice Sheet West Antarctica |
institution |
Open Polar |
collection |
Columbia University: Academic Commons |
op_collection_id |
ftcolumbiauniv |
language |
English |
topic |
Geophysics Ice shelves Geomorphology Continental margins Bathymetric maps |
spellingShingle |
Geophysics Ice shelves Geomorphology Continental margins Bathymetric maps Cochran, James R. Tinto, Kirsteen J. Bell, Robin E. Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica |
topic_facet |
Geophysics Ice shelves Geomorphology Continental margins Bathymetric maps |
description |
Inversion of NASA Operation IceBridge airborne gravity over the Abbot Ice Shelf in West Antarctica for subice bathymetry defines an extensional terrain made up of east-west trending rift basins formed during the early stages of Antarctica/Zealandia rifting. Extension is minor, as rifting jumped north of Thurston Island early in the rifting process. The Amundsen Sea Embayment continental shelf west of the rifted terrain is underlain by a deeper, more extensive sedimentary basin also formed during rifting between Antarctica and Zealandia. A well-defined boundary zone separates the mildly extended Abbot extensional terrain from the deeper Amundsen Embayment shelf basin. The shelf basin has an extension factor, b, of 1.5–1.7 with 80–100 km of extension occurring across an area now 250 km wide. Following this extension, rifting centered north of the present shelf edge and proceeded to continental rupture. Since then, the Amundsen Embayment continental shelf appears to have been tectonically quiescent and shaped by subsidence, sedimentation, and the advance and retreat of the West Antarctic Ice Sheet. The Bellingshausen Plate was located seaward of the Amundsen Sea margin prior to incorporation into the Antarctic Plate at about 62 Ma. During the latter part of its independent existence, Bellingshausen plate motion had a clockwise rotational component relative to Antarctica producing convergence across the north-south trending Bellingshausen Gravity Anomaly structure at 94°W and compressive deformation on the continental slope between 94°W and 102°W. Farther west, the relative motion was extensional along an east-west trending zone occupied by the Marie Byrd Seamounts. |
format |
Article in Journal/Newspaper |
author |
Cochran, James R. Tinto, Kirsteen J. Bell, Robin E. |
author_facet |
Cochran, James R. Tinto, Kirsteen J. Bell, Robin E. |
author_sort |
Cochran, James R. |
title |
Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica |
title_short |
Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica |
title_full |
Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica |
title_fullStr |
Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica |
title_full_unstemmed |
Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica |
title_sort |
abbot ice shelf, structure of the amundsen sea continental margin and the southern boundary of the bellingshausen plate seaward of west antarctica |
publishDate |
2015 |
url |
https://doi.org/10.7916/d8-66p2-2s41 |
long_lat |
ENVELOPE(-96.000,-96.000,-72.750,-72.750) ENVELOPE(-97.500,-97.500,-71.833,-71.833) ENVELOPE(-99.000,-99.000,-72.167,-72.167) |
geographic |
Abbot Ice Shelf Amundsen Sea Antarctic Byrd The Antarctic Thurston Thurston Island West Antarctic Ice Sheet West Antarctica |
geographic_facet |
Abbot Ice Shelf Amundsen Sea Antarctic Byrd The Antarctic Thurston Thurston Island West Antarctic Ice Sheet West Antarctica |
genre |
Abbot Ice Shelf Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Thurston Island West Antarctica |
genre_facet |
Abbot Ice Shelf Amundsen Sea Antarc* Antarctic Antarctica Ice Sheet Ice Shelf Ice Shelves Thurston Island West Antarctica |
op_relation |
https://doi.org/10.7916/d8-66p2-2s41 |
op_doi |
https://doi.org/10.7916/d8-66p2-2s41 |
_version_ |
1766339995902148608 |