A number of small but deep shelf-basins reaching water depths in excess of 1000 m have been identified west of the northern Antarctic Peninsula (NAP). The best known is Palmer Deep, a 1400 m deep erosional inner-shelf depression located off Anvers Island. Both stratigraphic observations and specific seafloor features in and around Palmer Deep have been linked to the development of a subglacial lake prior to or during the Last Glacial Maximum (LGM), followed by estuarine and open-marine conditions since that time (Domack et al. 2006). Here, several small shelf-basins are examined, located 200 km NE of Palmer Deep in western Bransfield Strait (Fig. 1a, g).
Small, deep shelf-basins in western Bransfield Strait. (a) Multibeam-bathymetric image. JPC-32 and JPC-33 are sediment cores that recovered Holocene diatom-bearing muds in their upper 10 m. NB, GB, FB and EB refer to Needle, Gullet, Fig and The Eye basins. Acquisition system Simrad EM12-S. Frequency 12.5 kHz. Grid-cell size 200 m (colour) and GEBCO_08 grid (grey). Land is from the Landsat Image Mosaic of Antarctica (US Geological Survey). (b) Fig Basin. (c) Gradient map of Fig Basin showing its flat floor and smooth to very steep slopes. (d) Map of Needle, Gullet and The Eye basins. (e) Fig Basin transverse (VE×4) and long-axis (VE×8) bathymetric profiles. (f) High-resolution …