Multichannel seismic reflection profiles provide a record of the glacial development in the western Amundsen Sea Embayment during the Neogene. We identified a northwest-dipping reflector series of more than 1 s TWT thickness (> 800 m) on the middle continental shelf indicating well-layered sedimentary units. The dipping strata reveal a striking alternation of reflection-poor, almost transparent units and sequences of closely spaced, continuous reflectors. We suggest that the distinct changes in reflection character represent episodes of ice sheet advance and retreat forced by climate changes. The similarity to seismo-stratigraphic records from the Ross Sea suggests that dipping strata have accumulated since the Miocene. A major problem is to define the age of the dipping strata and with it the episodes of ice sheet extension because drill sites do not exist within the Amundsen Basin. Therefore a future research priority will be the collection of a series of core samples. The outcrop of layers along large parts of the shelf and the shallow water depth provide a favorable base for shallow drilling.
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