Bedrock channels in Pine Island Bay, West Antarctica

The seafloor of inner continental shelves on glaciated margins is sometimes stripped of most of the softer sediments, leaving bedrock exposed (Wellner et al. 2001). Examples of such exposed bedrock regions have been observed in the inner parts of several cross-shelf troughs on the West Antarctica margin, including those in the Amundsen Sea (Lowe & Anderson 2003; Graham et al. 2009) and Marguerite Bay (Anderson & Fretwell 2008). The detailed morphology of these areas consists of various features of glacial origin, predominantly parallel grooves or striations. These areas can also contain sinuous channels that are incised deeply into the rock substrate.