Flow and Retreat of the Late Quaternary Pine Island-Thwaites Palaeo-ice Stream, West Antarctica
[1] Multibeam swath bathymetry and sub-bottom profiler data are used to establish constraints on the flow and retreat history of a major palaeo-ice stream that carried the combined discharge from the parts of the West Antarctic Ice Sheet now occupied by the Pine Island and Thwaites glacier basins. S...
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ftunisfloridatam:oai:digitalcommons.usf.edu:msc_facpub-2572 2023-05-15T14:04:11+02:00 Flow and Retreat of the Late Quaternary Pine Island-Thwaites Palaeo-ice Stream, West Antarctica Graham, Alastair G. C. Larter, Robert D. Gohl, Karsten Dowdeswell, Julian A. Hillenbrand, Claus-Dieter Smith, James A. Evans, Jeffrey Kuhn, Gerhard Deen, Tara 2010-01-01T08:00:00Z application/pdf https://digitalcommons.usf.edu/msc_facpub/1522 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2572&context=msc_facpub unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/1522 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2572&context=msc_facpub default Marine Science Faculty Publications ice streams West Antarctica Late Quaternary Life Sciences article 2010 ftunisfloridatam 2022-01-20T18:39:05Z [1] Multibeam swath bathymetry and sub-bottom profiler data are used to establish constraints on the flow and retreat history of a major palaeo-ice stream that carried the combined discharge from the parts of the West Antarctic Ice Sheet now occupied by the Pine Island and Thwaites glacier basins. Sets of highly elongated bedforms show that, at the last glacial maximum, the route of the Pine Island-Thwaites palaeo-ice stream arced north-northeast following a prominent cross-shelf trough. In this area, the grounding line advanced to within ∼68 km of, and probably reached, the shelf edge. Minimum ice thickness is estimated at 715 m on the outer shelf, and we estimate a minimum ice discharge of ∼108 km3 yr−1 assuming velocities similar to today's Pine Island glacier (∼2.5 km yr−1). Additional bed forms observed in a trough northwest of Pine Island Bay likely formed via diachronous ice flows across the outer shelf and demonstrate switching ice stream behavior. The “style” of ice retreat is also evident in five grounding zone wedges, which suggest episodic deglaciation characterized by halts in grounding line migration up-trough. Stillstands occurred in association with changes in ice bed gradient, and phases of inferred rapid retreat correlate to higher bed slopes, supporting theoretical studies that show bed geometry as a control on ice margin recession. However, estimates that individual wedges could have formed within several centuries still imply a relatively rapid overall retreat. Our findings show that the ice stream channeled a substantial fraction of West Antarctica's discharge in the past, just as the Pine Island and Thwaites glaciers do today. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Pine Island Pine Island Bay Pine Island Glacier Thwaites Glacier West Antarctica Digital Commons University of South Florida (USF) Antarctic West Antarctica West Antarctic Ice Sheet Pine Island Glacier ENVELOPE(-101.000,-101.000,-75.000,-75.000) Island Bay ENVELOPE(-109.085,-109.085,59.534,59.534) Pine Island Bay ENVELOPE(-102.000,-102.000,-74.750,-74.750) Thwaites Glacier ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
institution |
Open Polar |
collection |
Digital Commons University of South Florida (USF) |
op_collection_id |
ftunisfloridatam |
language |
unknown |
topic |
ice streams West Antarctica Late Quaternary Life Sciences |
spellingShingle |
ice streams West Antarctica Late Quaternary Life Sciences Graham, Alastair G. C. Larter, Robert D. Gohl, Karsten Dowdeswell, Julian A. Hillenbrand, Claus-Dieter Smith, James A. Evans, Jeffrey Kuhn, Gerhard Deen, Tara Flow and Retreat of the Late Quaternary Pine Island-Thwaites Palaeo-ice Stream, West Antarctica |
topic_facet |
ice streams West Antarctica Late Quaternary Life Sciences |
description |
[1] Multibeam swath bathymetry and sub-bottom profiler data are used to establish constraints on the flow and retreat history of a major palaeo-ice stream that carried the combined discharge from the parts of the West Antarctic Ice Sheet now occupied by the Pine Island and Thwaites glacier basins. Sets of highly elongated bedforms show that, at the last glacial maximum, the route of the Pine Island-Thwaites palaeo-ice stream arced north-northeast following a prominent cross-shelf trough. In this area, the grounding line advanced to within ∼68 km of, and probably reached, the shelf edge. Minimum ice thickness is estimated at 715 m on the outer shelf, and we estimate a minimum ice discharge of ∼108 km3 yr−1 assuming velocities similar to today's Pine Island glacier (∼2.5 km yr−1). Additional bed forms observed in a trough northwest of Pine Island Bay likely formed via diachronous ice flows across the outer shelf and demonstrate switching ice stream behavior. The “style” of ice retreat is also evident in five grounding zone wedges, which suggest episodic deglaciation characterized by halts in grounding line migration up-trough. Stillstands occurred in association with changes in ice bed gradient, and phases of inferred rapid retreat correlate to higher bed slopes, supporting theoretical studies that show bed geometry as a control on ice margin recession. However, estimates that individual wedges could have formed within several centuries still imply a relatively rapid overall retreat. Our findings show that the ice stream channeled a substantial fraction of West Antarctica's discharge in the past, just as the Pine Island and Thwaites glaciers do today. |
format |
Article in Journal/Newspaper |
author |
Graham, Alastair G. C. Larter, Robert D. Gohl, Karsten Dowdeswell, Julian A. Hillenbrand, Claus-Dieter Smith, James A. Evans, Jeffrey Kuhn, Gerhard Deen, Tara |
author_facet |
Graham, Alastair G. C. Larter, Robert D. Gohl, Karsten Dowdeswell, Julian A. Hillenbrand, Claus-Dieter Smith, James A. Evans, Jeffrey Kuhn, Gerhard Deen, Tara |
author_sort |
Graham, Alastair G. C. |
title |
Flow and Retreat of the Late Quaternary Pine Island-Thwaites Palaeo-ice Stream, West Antarctica |
title_short |
Flow and Retreat of the Late Quaternary Pine Island-Thwaites Palaeo-ice Stream, West Antarctica |
title_full |
Flow and Retreat of the Late Quaternary Pine Island-Thwaites Palaeo-ice Stream, West Antarctica |
title_fullStr |
Flow and Retreat of the Late Quaternary Pine Island-Thwaites Palaeo-ice Stream, West Antarctica |
title_full_unstemmed |
Flow and Retreat of the Late Quaternary Pine Island-Thwaites Palaeo-ice Stream, West Antarctica |
title_sort |
flow and retreat of the late quaternary pine island-thwaites palaeo-ice stream, west antarctica |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2010 |
url |
https://digitalcommons.usf.edu/msc_facpub/1522 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2572&context=msc_facpub |
long_lat |
ENVELOPE(-101.000,-101.000,-75.000,-75.000) ENVELOPE(-109.085,-109.085,59.534,59.534) ENVELOPE(-102.000,-102.000,-74.750,-74.750) ENVELOPE(-106.750,-106.750,-75.500,-75.500) |
geographic |
Antarctic West Antarctica West Antarctic Ice Sheet Pine Island Glacier Island Bay Pine Island Bay Thwaites Glacier |
geographic_facet |
Antarctic West Antarctica West Antarctic Ice Sheet Pine Island Glacier Island Bay Pine Island Bay Thwaites Glacier |
genre |
Antarc* Antarctic Antarctica Ice Sheet Pine Island Pine Island Bay Pine Island Glacier Thwaites Glacier West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Pine Island Pine Island Bay Pine Island Glacier Thwaites Glacier West Antarctica |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/1522 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2572&context=msc_facpub |
op_rights |
default |
_version_ |
1766275201414201344 |