History of, and Mechanisms Leading to, Post-LGM Retreat of the West Antarctic

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AbstractPI: John B. AndersonProposal Number: 0837925Title: History of, and Mechanisms Leading to, Post-LGM Retreat of the West Antarctic Ice SheetThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The West Antarctic Ice Sheet is believed to be vulnerable to climate change as it is grounded below sea level, is drained by rapidly flowing ice streams and is fringed by floating ice shelves subject to melting by incursions of relatively warm Antarctic circumpolar water. Currently, the most rapidly thinning glaciers in Antarctica occur in the Amundsen and Bellingshausen Sea sectors. This study seeks to place the present day observations into a longer-term geological context. Mechanisms that led to the retreat of the ice sheet from the West Antarctic continental shelf since the last glacial maximum will be investigated. This study will build on a number of previous investigations and fill in key data gaps in the region. Bathymetric mapping and direct sampling of relict glacial features on the continental shelves of the Bellingshausen (Marguerite Bay), Amundsen (Pine Island Bay) and eastern Ross Seas will be conducted via dedicated science time on the Swedish Icebreaker Oden. Sites for Kasten coring will be selected on the basis of detailed swath mapping. Radiocarbon dating of glaciomarine deposits in the new and existing cores will refine the timing of retreat events. Geomorphic features of paleo ice streams such as grounding line wedges and ice scours will be examined to assess whether the retreat occurred continuously and/or episodically. Sediments will be examined for paleontological evidence of warm ocean water intrusions during retreat as well as for mineral evidence of possible melt water origins.Broader impacts:This project is collaborative with colleagues from the US, Sweden, the UK, France, Japan and Poland. It will entail the training of three PhD students at Rice University and so afford them international field work experience. One of these will be transitioning to post-doc status in the course of this project. An undergraduate student will also be involved in the fieldwork phase of the research. The PI expects to continue to be active in Rice University's Houston area high school teacher outreach program as well as a separate program to convey science to elderly people confined in assisted living and retirement facilities.