New details about the LGM extent and subsequent retreat of the West Antarctic Ice Sheet from the easternmost Amundsen Sea Embayment shelf


Contact
gerhard.kuhn [ at ] awi.de

Abstract

In recent years several previously undiscovered grounding-zone wedges (GZWs) have been described within the Abbot-Cosgrove palaeo-ice stream trough on the easternmost Amundsen Sea Embayment shelf. These GZWs document both the Last Glacial Maximum (LGM; 26.5-19 cal. ka BP) grounding-line extent and the subsequent episodic retreat within this trough that neighbors the larger Pine Island-Thwaites trough to the west. Here we combine bathymetric, seismic, and geologic data showing that 1) the grounding line in Abbot Trough did not reach the continental shelf break at any time during the last glacial period, and 2) a prominent stacked GZW constructed from six individual wedges lying upon another was deposited 100 km upstream from the LGM grounding-line position. The available data allow for calculating volumes for most of these individual GZWs and for the entire stack. Sediment cores were recovered seawards from the outermost GZW in the trough, and from the individual wedges of the stacked GZW in order to define the LGM grounding-line extent, and provide minimum grounding-line retreat ages for the respective positions on the stacked GZW. We present implications of a grounded-ice free outer shelf throughout the last glacial period. Furthermore, we assess the significance of the grounding-line stillstand period recorded by the stacked GZW in Abbot Trough for the timing of post-LGM retreat of the West Antarctic Ice Sheet from the Amundsen Sea Embayment shelf.



Item Type
Conference (Poster)
Authors
Divisions
Primary Division
Programs
Primary Topic
Peer revision
Not peer-reviewed
Publication Status
Published
Event Details
AGU Fall Meeting, 10 Dec 2017 - 15 Dec 2017, New Orleans, Louisiana, USA.
Eprint ID
46093
Cite as
Klages, J. P. , Hillenbrand, C. D. , Smith, J. A. , Kuhn, G. , Graham, A. G. C. , Nitsche, F. O. , Frederichs, T. , Arndt, J. E. , Gebhardt, C. , Zindler, R. , Uenzelmann-Neben, G. , Gohl, K. , Jernas, P. E. , Wacker, L. and PS104, S. S. P. (2017): New details about the LGM extent and subsequent retreat of the West Antarctic Ice Sheet from the easternmost Amundsen Sea Embayment shelf , AGU Fall Meeting, New Orleans, Louisiana, USA, 10 December 2017 - 15 December 2017 .


Download
[img]
Preview
PDF
Poster.pdf

Download (57MB) | Preview

Share

Research Platforms

Campaigns


Actions
Edit Item Edit Item