IODP Expedition 379; development and sensitivity of the West Antarctic ice sheet tested from drill records of the Amundsen Sea Embayment

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Author(s): Gohl, Karsten; Wellner, Julia; Klaus, Adam
Author Affiliation(s): Primary:
Alfred Wegener Institute, Helmholtz-Centre for Polar and Marine Research, Bremerhaven, Germany
University of Houston, United States
Texas A&M University, United States
Volume Title: European Geosciences Union general assembly 2019
Source: Geophysical Research Abstracts, Vol.21; European Geosciences Union general assembly 2019, Vienna, Austria, April 7-12, 2019. Publisher: Copernicus GmbH on behalf of the European Geosciences Union (EGU), Katlenburg-Lindau, Germany. ISSN: 1029-7006
Note: In English
Summary: Its submarine base and exposure to warm shelf waters makes the West Antarctic Ice Sheet (WAIS) highly vulnerable to climatic and oceanographic changes. Modelling infers that the WAIS has likely had a very dynamic history throughout the Neogene to the present. A complete collapse of the WAIS would result in a global sea level rise of 3.3 to 4.3 m, yet there is large uncertainty on predicting its future behavior and its role in sea level rise. Geological data on the past behavior of the WAIS are relatively sparsely and unequally distributed, in particular records of time intervals with climatic conditions similar to those expected for the near and distant future. Reconstructions and quantifications of partial or complete WAIS collapses in the past are therefore urgently needed for constraining and testing ice sheet models that aim to project future WAIS behavior. JOIDES Resolution departed from Punta Arenas in mid-January 2019 for IODP Expedition 379 to drill sites on the continental shelf and rise of the Amundsen Sea Embayment (ASE), where records are expected to represent dynamical advance and retreat processes of the central part of the WAIS. This embayment is of particular significance for studying WAIS dynamics as this sector currently experiences the largest ice mass loss in Antarctica, driven by ocean heat transport to the cavities of the main outlet glaciers. The plan was to drill a series of sites on the shelf where seismic data reveal seaward-dipping sedimentary sequences that span from the preglacial depositional phase to the most recent glacial periods. Deep-water sites on the continental rise were selected for recovering continuous records of glacially transported sediments and detailed archives of climatic and oceanographic changes throughout glacial-interglacial cycles. In this presentation, we will provide on-hand information of the recently completed drilling operation in a notoriously ice-infested environment as well as first preliminary drilling results with regard to our objectives of reconstructing the onset of glaciation in the greenhouse to icehouse transition, processes of dynamic ice sheet behavior during the Neogene and Quaternary, and ocean conditions associated with the glacial cycles. [Copyright Author(s) 2019. CC Attribution 4.0 License:]
Year of Publication: 2019
Research Program: IODP2 International Ocean Discovery Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; Amundsen Sea; Antarctic ice sheet; Antarctica; Cenozoic; Climate effects; Continental margin; Cores; Deglaciation; Expedition 379; International Ocean Discovery Program; Marine sediments; Neogene; Paleoclimatology; Quaternary; Sediments; Tertiary; West Antarctic ice sheet
Coordinates: S750000 S650000 W1020000 W1260000
Record ID: 2019050514
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from European Geosciences Union, Munich, Germany