MODIS Terra image (at 250 m resolution) acquired on 2 January 2011 showing early-summer sea ice coverage in the Amundsen Sea region and open water extents in the two coastal polynyas. Place names are, from east to west: Pine Island Ice Shelf (PIIS), Pine Island Polynya (PIP), Thwaites (eastern) Ice Shelf (TIS), Thwaites Glacier Tongue (TGT), Thwaites Iceberg Tongue (TIBT), Thwaites Fast-ice Tongue (TFT), Crosson Ice Shelf (CIS), Bear Peninsula (BP), Dotson Ice Shelf (DIS), Amundsen Sea Polynya (ASP), Martin Peninsula (MP), and Getz Ice Shelf (GIS). The coastline (in red) is from MOA 2009 (Haran et al., 2014). (A) European Space Agency Envisat SAR image from 26 January 2009 revealing details of the TGT, TIBT and TFT. The relatively smooth surface of the fast ice appears dark relative to the rougher surface of the small icebergs within and bordering the TFT, and relative to the rougher surfaces of the TGT and TIBT. (B) Location map. (C) Bathymetry of the Amundsen Sea continental shelf region (blue-gray shading at 100-m depth intervals) (Nitsche et al., 2007). (D) The westward drift tracks of three ice buoys deployed in the Bellingshausen Sea (BS) in March 2007; drift ended in the Amundsen Sea (AS).