Seismic stratigraphic record of West Antarctic ice sheet fluctuations within the Eastern Basin of the Ross Sea, Antarctica.

摘要

Using geophysical data collected aboard the R/V Nathaniel B. Palmer during the austral summer of 2004 the stratigraphy of the up-dip portion of the Antarctic margin was studied. Analysis of up-dip SCS profiles illustrated an incomplete glacial record with multiple thin, polar Plio-Pleistocene sequences reflecting the presence of Northern Hemisphere ice, and fewer, thick Early Miocene sequences indicating perhaps a subpolar basal regime. Across the shelf of the Eastern Basin, the majority of the sequences terminate mid-shelf suggesting that not all ice sheet events are the same magnitude, which may be a function of climate change or autogenic ice sheet fluctuations. Through quantitative analysis the up-dip stratigraphy of the Eastern Basin was shown to be highly heterogeneous. This work has provided a more robust illustration of the complexity of glacial stratigraphy in the up-dip setting, and it is possible to see a reflection of changing climate preserved in the seismic signature of the NBP 0306 profiles.