The West Antarctic Ice Sheet (WAIS) is likely to have been subject of a very dynamic activity during its history as most of its base is grounded below present sea-level and, thus, is sensitive to climatic changes. Its collapse would result in a global sea-level rise of 3-5 m. The reconstruction and quantification of partial or complete WAIS collapses in the geological past will provide necessary constraints for ice-sheet models predicting its future behaviour and resulting sea-level rise. Large uncertainties exist regarding the chronology, extent, rates and spatial and temporal variability of past advances and retreats of the WAIS across the continental shelves. These uncertainties are mainly due to the lack of drill information. By using a ship-mounted shallow drilling device, e.g. the MeBo system, a series of core samples can be drilled on the shelf of the Amundsen Sea Embayment (ASE) where high-quality seismic data reveal seaward-dipping sediment sequences covered only by a thin veneer of glacial till. In a transect drilling strategy, a series of cores from the oldest sequences close to the bedrock-basin boundary in the south to the youngest sequences in the north of the western and eastern ASE shelf can be sampled. Based on the seismic results, it is expected that up to 800 m of the sedimentary column can be sampled by shallow transect drilling. Further cores can be drilled in grounding zone wedges in order to understand the processes controlling the ice flow and timing of the last glacial cycle.
Helmholtz Research Programs > PACES I (2009-2013) > TOPIC 3: Lessons from the Past > WP 3.2: Tectonic, Climate and Biosphere Development from Greenhouse to Icehouse