Expressions of Intent for International Polar Year 2007-2008 Activities

Expression of Interest Details

PROPOSAL INFORMATION

Ice-sheet evolution in the Amundsen Sea since the last glacial maximum - geological perspectives  (ASEP-GEO)

Outline
We propose a program of geologic studies in the Amundsen Sea Embayment to: (1) Determine the extent of deposits marking the last glacial maximum (LGM) in this basin, and those laid down during glacial retreat. (2) Examine islands in and around Pine Island Bay for additional evidence of glacial retreat and isostatic rebound. (3) Date relevant deposits to establish the timing of the glacial maximum and the retreat history of Pine Island, Thwaites and adjoining glaciers, up to the present day. The main objective of this work is to provide long-term (millennial-scale) context for glaciological, geophysical, oceanographic and remote-sensing studies of ongoing changes in this sector of the West Antarctic Ice Sheet (WAIS). We do not know whether rapid thinning and grounding-line retreat that have been detected in satellite-based studies of this region are the continuation of a long-term trend, or mark the end of a period of Holocene stability. Geologists will visit ice-free areas in the Hudson Mts, north-east of Pine Island Glacier, Mt Murphy, west of Thwaites Glacier, and islands in Pine Island Bay. Participants will map glacial deposits and landforms, soils, coastal deposits such as raised beaches, etc, to delineate the former ice thickness on land, the history of ice retreat, and the deglaciation or emergence of islands in the Bay. Samples will be collected from glacial deposits, lake sediments, beach deposits, etc, and their ages determined using a combination of exposure dating, C-14 and U-series dating, tephrochronology and luminescence methods, as appropriate. The techniques required have been developed and refined, especially over the past decade, in work on the glacial history of the Ross Sea. Results will be closely integrated with marine geophysical work (some of which has already been carried out by the Rice University group) on the stratigraphy and structure of sediments offshore, which define the lateral extent and retreat history of the LGM ice sheet. Age constraints from shallow marine cores will provide complementary information on the deglaciation history, and faunal assemblages in such cores may help to identify past changes in oceanic circulation associated with glacial retreat and the break-up of ice shelves fronting this sector of the WAIS. Logistic support for this work would also provide opportunities for bedrock mapping aimed at understanding the plate-tectonic history, crustal dynamics and long-term (million-year) glacial history of this part of West Antarctica.

What significant advance(s) in relation to the IPY themes and targets can be anticipated from this project?
The thickness and extent of glaciers draining to the Amundsen Sea are changing faster than those in any other region of West Antarctica. We do not know whether recent thinning and grounding-line retreat are part of a prolonged deglaciation and adjustment to Holocene conditions, or a recently initiated destabilization of this sector of the ice sheet. Geologic studies and dating of ice retreat since the last glacial maximum will provide the context necessary to answer this question.

What international collaboration is involved in this project?
This work was discussed by US- and UK-based researchers in formulating the umbrella Amundsen Sea Embayment Project (ASEP) science plan in 2001. The British Antarctic Survey (BAS) has already committed support for glacial geologic work in the Hudson Mts during IPY.

FIELD ACTIVITY DETAILS

Geographical location(s) for the proposed field activities:
Nunataks bordering Pine Island, Thwaites, Koehler and Smith Glaciers (principally Hudson Mts and Mt Murphy). Islands in Pine Island Bay and fronting Canisteo Peninsula.

Approximate timeframe(s) for proposed field activities:
Arctic: n/a
Antarctic: Dec 2007 - Jan 2008      Dec 2008 - Jan 2009      

Significant facilities will be required for this project:
Helicopter-equipped ice-breaker, for access to nunataks and islands. Fixed-wing aircraft (Twin Otter) may be required to reach inland sites. Alternatively, LC-130 for initial deployment, assisted by Twin Otter for camp moves/access to inland nunataks. Work on islands will require ship/helicopter support.

Will the project leave a legacy of infrastructure?
No.

How is it envisaged that the required logistic support will be secured?
Consortium
Own national polar operator
National agency

Has the project been "endorsed" at a national or international level?
An umbrella proposal has been submitted to the US-IPY committee.

PROJECT MANAGEMENT AND STRUCTURE

Is the project a short-term expansion (over the IPY 2007-2008 timeframe) of an existing plan, programme or initiative or is it a new autonomous proposal?
New

This work was foreshadowed in the 2001 Amundsen Sea Embayment Plan (ASEP; http://igloo.gsfc.nasa.gov/wais/links/ASEP-final.pdf).

How will the project be organised and managed?
Small semi-autonomous groups will define and carry out their own research programs addressing the aims outlined in section 1.3 above. We anticipate that 3-5 groups of researchers interested in the late Quaternary glacial history of the region will seek funding to participate (three have already expressed this intention). Groups will present their findings, produce a synthesis of results and exchange data with marine geologists, glaciologists, geophysicists and oceanographers at annual WAIS workshops.

What are the initial plans of the project for addressing the education, outreach and communication issues outlined in the Framework document?
Recipients of NSF support are required to include educational activities and community outreach in the scope of their work. Participants in this work will present their findings to schools and community organizations, build websites (or expand existing sites) to disseminate results, and involve undergraduate and graduate students in the research.

What are the initial plans of the project to address data management issues (as outlined in the Framework document?
Results will be archived with the US National Snow and Ice Data Center (NSIDC) and World Data Centers. Note that this is mandatory for researchers who receive funding from the US National Science Foundation.

How is it proposed to fund the project?
US-based researchers will seek support from the National Science Foundation. BAS has already indicated support for geologic work in the Hudson Mts.

Is there additional information you wish to provide?
None

PROPOSER DETAILS

Dr John Stone
Dept of Earth and Space Sciences
Box 351310, University of Washington
Seattle, Washington
98195-1310
USA

Tel: + 1 206 221-6332
Mobile: no
Fax: no
Email:

Other project members and their affiliation