We present a new compilation of multibeam-bathymetric data for the inner Amundsen Sea continental shelf beyond Thwaites and Pine Island glaciers (bounding box: 100W to 110W, 74S to 75.5S). The region includes Pine Island Bay, marine areas offshore the Thwaites Ice Shelf to the Crosson Ice Shelf, and covers an area of 74,750 km2. The bathymetric grids were compiled from all available multibeam echosounder (MBES) data acquired by UK, German, USA and Korean scientific cruises to the area between 1999 and 2019 (see lineage). Three grids of sea floor elevation data are available in a range of formats (ESRI ascii interchange format and GMT-compatible netCDF 4byte float): a 50-m resolution grid with no interpolation, a 50-m grid interpolated up to 300 m from cells with real data, and a 500-m resolution grid with no interpolation. Note that these grids have not been merged with regional bathymetric grids and, therefore, do not have continuous coverage (i.e. cells are only populated where multibeam data exist). This work was supported by grants from the National Science Foundation (NSF: Grant OPP- 1738942) and Natural Environment Research Council (NERC: Grant NE/S006664/1) as part of the International Thwaites Glacier Collaboration (ITGC) programme, and grants NE/J005770/1 and NE/J005703/1 as part of the iSTAR Programme.

We present two new gridded bathymetric compilations of the Orkney Passage, Scotia Sea here defined by the following bounding boxes: 39.1 to 39.6 W, 60.55 to 60.7 S and 41.7 to 42.6 W, 60.45 to 60.8 S. These bathymetry grids were compiled from a variety of multibeam swath bathymetry data acquired during 12 different cruises (see lineage). The data is available as grids of 50 m resolution in a GMT-compatible (2-D) NetCDF format using geographic coordinates on the WGS84 datum. This grid was compiled in support of the ongoing monitoring efforts in and around Orkney Passage as part of the Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) programme and preceding BAS NC projects, and the Dynamics of the Orkney Passage Outflow (DynOPO) project. Funding was provided by the NERC grants NE/K012843/1 and NE/N018095/1 as well as national capability