Sedimentological analysis of eight cores from the Amundsen Sea
Recent palaeoglaciological studies on the West Antarctic shelf have mainly focused on the wide embayments of the Ross and Amundsen seas in order to reconstruct the extent and subsequent retreat of the West Antarctic Ice Sheet (WAIS) since the Last Glacial Maximum (LGM). However, the narrower shelf s...
Main Authors: | , , , , , , |
---|---|
Format: | Dataset |
Language: | English |
Published: |
PANGAEA
2014
|
Subjects: | |
Online Access: | https://doi.pangaea.de/10.1594/PANGAEA.818175 https://doi.org/10.1594/PANGAEA.818175 |
id |
ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.818175 |
---|---|
record_format |
openpolar |
institution |
Open Polar |
collection |
PANGAEA - Data Publisher for Earth & Environmental Science |
op_collection_id |
ftpangaea |
language |
English |
topic |
ANT-XXVI/3 AWI_Paleo Giant box corer GKG Gravity corer (Kiel type) Paleoenvironmental Reconstructions from Marine Sediments @ AWI Polarstern PS75 PS75/128-1 PS75/129-1 PS75/130-1 PS75/132-3 PS75/133-1 PS75/136-3 PS75/138-1 PS75/139-2 SL westernmost Getz Trough inner-middle shelf (MSGLs) inner shelf (basin north of GZW) inner shelf (basin south of GZW) inner shelf (lineations on acoustic basement) inner shelf (location with pre-glacial (?) sediments) inner shelf (meltwater channel) inner shelf (near ice-shelf edge) outer shelf (iceberg scours with subbottom reflector) |
spellingShingle |
ANT-XXVI/3 AWI_Paleo Giant box corer GKG Gravity corer (Kiel type) Paleoenvironmental Reconstructions from Marine Sediments @ AWI Polarstern PS75 PS75/128-1 PS75/129-1 PS75/130-1 PS75/132-3 PS75/133-1 PS75/136-3 PS75/138-1 PS75/139-2 SL westernmost Getz Trough inner-middle shelf (MSGLs) inner shelf (basin north of GZW) inner shelf (basin south of GZW) inner shelf (lineations on acoustic basement) inner shelf (location with pre-glacial (?) sediments) inner shelf (meltwater channel) inner shelf (near ice-shelf edge) outer shelf (iceberg scours with subbottom reflector) Klages, Johann Philipp Kuhn, Gerhard Hillenbrand, Claus-Dieter Graham, Alastair G C Smith, James A Larter, Robert D Gohl, Karsten Sedimentological analysis of eight cores from the Amundsen Sea |
topic_facet |
ANT-XXVI/3 AWI_Paleo Giant box corer GKG Gravity corer (Kiel type) Paleoenvironmental Reconstructions from Marine Sediments @ AWI Polarstern PS75 PS75/128-1 PS75/129-1 PS75/130-1 PS75/132-3 PS75/133-1 PS75/136-3 PS75/138-1 PS75/139-2 SL westernmost Getz Trough inner-middle shelf (MSGLs) inner shelf (basin north of GZW) inner shelf (basin south of GZW) inner shelf (lineations on acoustic basement) inner shelf (location with pre-glacial (?) sediments) inner shelf (meltwater channel) inner shelf (near ice-shelf edge) outer shelf (iceberg scours with subbottom reflector) |
description |
Recent palaeoglaciological studies on the West Antarctic shelf have mainly focused on the wide embayments of the Ross and Amundsen seas in order to reconstruct the extent and subsequent retreat of the West Antarctic Ice Sheet (WAIS) since the Last Glacial Maximum (LGM). However, the narrower shelf sectors between these two major embayments have remained largely unstudied in previous geological investigations despite them covering extensive areas of the West Antarctic shelf. Here, we present the first systematic marine geological and geophysical survey of a shelf sector offshore from the Hobbs Coast. It is dominated by a large grounding zone wedge (GZW), which fills the base of a palaeo-ice stream trough on the inner shelf and marks a phase of stabilization of the grounding line during general WAIS retreat following the last maximum ice-sheet extent in this particular area (referred to as the Local Last Glacial Maximum, 'LLGM'). Reliable age determination on calcareous microfossils from the infill of a subglacial meltwater channel eroded into the GZW reveals that grounded ice had retreated landward of the GZW before ~20.88 cal. ka BP, with deglaciation of the innermost shelf occurring prior to ~12.97 cal. ka BP. Geophysical sub-bottom information from the inner-, mid- and outer shelf indicates grounded ice extended to the shelf edge prior to the formation of the GZW. Assuming the wedge was deposited during deglaciation, we infer the timing of maximum grounded ice extent occurred before ~20.88 cal. ka BP. This could suggest that the WAIS retreat from the outer shelf was already underway during or even prior to the global LGM (~23-19 cal. ka BP). Our new findings give insights into the regional deglacial behaviour of this understudied part of the West Antarctic shelf and at the same time support early deglaciation ages recently presented for adjacent drainage sectors of the WAIS. If correct, these findings contrast with the hypothesis that initial deglaciation of Antarctic Ice Sheets occurred synchronously at ~19 ... |
format |
Dataset |
author |
Klages, Johann Philipp Kuhn, Gerhard Hillenbrand, Claus-Dieter Graham, Alastair G C Smith, James A Larter, Robert D Gohl, Karsten |
author_facet |
Klages, Johann Philipp Kuhn, Gerhard Hillenbrand, Claus-Dieter Graham, Alastair G C Smith, James A Larter, Robert D Gohl, Karsten |
author_sort |
Klages, Johann Philipp |
title |
Sedimentological analysis of eight cores from the Amundsen Sea |
title_short |
Sedimentological analysis of eight cores from the Amundsen Sea |
title_full |
Sedimentological analysis of eight cores from the Amundsen Sea |
title_fullStr |
Sedimentological analysis of eight cores from the Amundsen Sea |
title_full_unstemmed |
Sedimentological analysis of eight cores from the Amundsen Sea |
title_sort |
sedimentological analysis of eight cores from the amundsen sea |
publisher |
PANGAEA |
publishDate |
2014 |
url |
https://doi.pangaea.de/10.1594/PANGAEA.818175 https://doi.org/10.1594/PANGAEA.818175 |
op_coverage |
MEDIAN LATITUDE: -74.362225 * MEDIAN LONGITUDE: -134.235108 * SOUTH-BOUND LATITUDE: -74.509000 * WEST-BOUND LONGITUDE: -135.055160 * NORTH-BOUND LATITUDE: -74.100160 * EAST-BOUND LONGITUDE: -133.078000 * DATE/TIME START: 2010-02-18T20:37:00 * DATE/TIME END: 2010-02-21T04:16:00 |
long_lat |
ENVELOPE(-57.500,-57.500,-64.300,-64.300) ENVELOPE(-145.217,-145.217,-76.550,-76.550) ENVELOPE(-136.000,-136.000,-75.500,-75.500) ENVELOPE(-135.055160,-133.078000,-74.100160,-74.509000) |
geographic |
Antarctic Amundsen Sea West Antarctic Ice Sheet Hobbs Getz Hobbs Coast |
geographic_facet |
Antarctic Amundsen Sea West Antarctic Ice Sheet Hobbs Getz Hobbs Coast |
genre |
Amundsen Sea Antarc* Antarctic Hobbs coast Ice Sheet Ice Shelf Iceberg* |
genre_facet |
Amundsen Sea Antarc* Antarctic Hobbs coast Ice Sheet Ice Shelf Iceberg* |
op_source |
Supplement to: Klages, Johann Philipp; Kuhn, Gerhard; Hillenbrand, Claus-Dieter; Graham, Alastair G C; Smith, James A; Larter, Robert D; Gohl, Karsten; Wacker, Lukas (2014): Retreat of the West Antarctic Ice Sheet from the western Amundsen Sea shelf at a pre- or early LGM stage. Quaternary Science Reviews, 91, 1-15, https://doi.org/10.1016/j.quascirev.2014.02.017 |
op_relation |
https://doi.pangaea.de/10.1594/PANGAEA.818175 https://doi.org/10.1594/PANGAEA.818175 |
op_rights |
CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1594/PANGAEA.818175 https://doi.org/10.1016/j.quascirev.2014.02.017 |
_version_ |
1766378809140969472 |
spelling |
ftpangaea:oai:pangaea.de:doi:10.1594/PANGAEA.818175 2023-05-15T13:24:20+02:00 Sedimentological analysis of eight cores from the Amundsen Sea Klages, Johann Philipp Kuhn, Gerhard Hillenbrand, Claus-Dieter Graham, Alastair G C Smith, James A Larter, Robert D Gohl, Karsten MEDIAN LATITUDE: -74.362225 * MEDIAN LONGITUDE: -134.235108 * SOUTH-BOUND LATITUDE: -74.509000 * WEST-BOUND LONGITUDE: -135.055160 * NORTH-BOUND LATITUDE: -74.100160 * EAST-BOUND LONGITUDE: -133.078000 * DATE/TIME START: 2010-02-18T20:37:00 * DATE/TIME END: 2010-02-21T04:16:00 2014-02-25 application/zip, 54 datasets https://doi.pangaea.de/10.1594/PANGAEA.818175 https://doi.org/10.1594/PANGAEA.818175 en eng PANGAEA https://doi.pangaea.de/10.1594/PANGAEA.818175 https://doi.org/10.1594/PANGAEA.818175 CC-BY-3.0: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted info:eu-repo/semantics/openAccess CC-BY Supplement to: Klages, Johann Philipp; Kuhn, Gerhard; Hillenbrand, Claus-Dieter; Graham, Alastair G C; Smith, James A; Larter, Robert D; Gohl, Karsten; Wacker, Lukas (2014): Retreat of the West Antarctic Ice Sheet from the western Amundsen Sea shelf at a pre- or early LGM stage. Quaternary Science Reviews, 91, 1-15, https://doi.org/10.1016/j.quascirev.2014.02.017 ANT-XXVI/3 AWI_Paleo Giant box corer GKG Gravity corer (Kiel type) Paleoenvironmental Reconstructions from Marine Sediments @ AWI Polarstern PS75 PS75/128-1 PS75/129-1 PS75/130-1 PS75/132-3 PS75/133-1 PS75/136-3 PS75/138-1 PS75/139-2 SL westernmost Getz Trough inner-middle shelf (MSGLs) inner shelf (basin north of GZW) inner shelf (basin south of GZW) inner shelf (lineations on acoustic basement) inner shelf (location with pre-glacial (?) sediments) inner shelf (meltwater channel) inner shelf (near ice-shelf edge) outer shelf (iceberg scours with subbottom reflector) Dataset 2014 ftpangaea https://doi.org/10.1594/PANGAEA.818175 https://doi.org/10.1016/j.quascirev.2014.02.017 2023-01-20T07:33:06Z Recent palaeoglaciological studies on the West Antarctic shelf have mainly focused on the wide embayments of the Ross and Amundsen seas in order to reconstruct the extent and subsequent retreat of the West Antarctic Ice Sheet (WAIS) since the Last Glacial Maximum (LGM). However, the narrower shelf sectors between these two major embayments have remained largely unstudied in previous geological investigations despite them covering extensive areas of the West Antarctic shelf. Here, we present the first systematic marine geological and geophysical survey of a shelf sector offshore from the Hobbs Coast. It is dominated by a large grounding zone wedge (GZW), which fills the base of a palaeo-ice stream trough on the inner shelf and marks a phase of stabilization of the grounding line during general WAIS retreat following the last maximum ice-sheet extent in this particular area (referred to as the Local Last Glacial Maximum, 'LLGM'). Reliable age determination on calcareous microfossils from the infill of a subglacial meltwater channel eroded into the GZW reveals that grounded ice had retreated landward of the GZW before ~20.88 cal. ka BP, with deglaciation of the innermost shelf occurring prior to ~12.97 cal. ka BP. Geophysical sub-bottom information from the inner-, mid- and outer shelf indicates grounded ice extended to the shelf edge prior to the formation of the GZW. Assuming the wedge was deposited during deglaciation, we infer the timing of maximum grounded ice extent occurred before ~20.88 cal. ka BP. This could suggest that the WAIS retreat from the outer shelf was already underway during or even prior to the global LGM (~23-19 cal. ka BP). Our new findings give insights into the regional deglacial behaviour of this understudied part of the West Antarctic shelf and at the same time support early deglaciation ages recently presented for adjacent drainage sectors of the WAIS. If correct, these findings contrast with the hypothesis that initial deglaciation of Antarctic Ice Sheets occurred synchronously at ~19 ... Dataset Amundsen Sea Antarc* Antarctic Hobbs coast Ice Sheet Ice Shelf Iceberg* PANGAEA - Data Publisher for Earth & Environmental Science Antarctic Amundsen Sea West Antarctic Ice Sheet Hobbs ENVELOPE(-57.500,-57.500,-64.300,-64.300) Getz ENVELOPE(-145.217,-145.217,-76.550,-76.550) Hobbs Coast ENVELOPE(-136.000,-136.000,-75.500,-75.500) ENVELOPE(-135.055160,-133.078000,-74.100160,-74.509000) |