Abstract. Sub-ice shelf circulation and freezing/melting rates in ocean general circulation models depend critically on an accurate and consistent representation of cavity geometry. Existing global or pan-Antarctic topography data sets have turned out to contain various inconsistencies and inaccuracies. The goal of this work is to compile independent regional surveys and maps into a global data set. We use the S-2004 global 1-min bathymetry as the backbone and add an improved version of the BEDMAP topography (ALBMAP bedrock topography) for an area that roughly coincides with the Antarctic continental shelf. The position of the merging line is individually chosen in different sectors in order to capture the best of both data sets. High-resolution gridded data for ice shelf topography and cavity geometry of the Amery, Fimbul, FilchnerRonne, Larsen C and George VI Ice Shelves, and for Pine Island Glacier are carefully merged into the ambient ice and ocean topographies. Multibeam survey data for bathymetry in the former Larsen B cavity and the southeastern Bellingshausen Sea have been obtained from the data centers of Alfred Wegener Institute (AWI), British Antarctic Survey (BAS) and Lamont-Doherty Earth Observatory (LDEO), gridded, and blended into the existing bathymetry map. The resulting global 1-min Refined Topography data set (RTopo-1) contains selfconsistent maps for upper and lower ice surface heights, bedrock topography, and surface type (open ocean, grounded ice, floating ice, bare land surface).

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Sub-ice shelf circulation and freezing/melting rates in ocean general circulation models depend critically on an accurate and consistent representation of cavity geometry. Existing global or pan-Antarctic data sets have turned out to contain various inconsistencies and inaccuracies. The goal of this work is to compile independent regional 5 fields into a global data set. We use the S-2004 global 1-min bathymetry as the backbone and add an improved version of the BEDMAP topography (ALBMAP bedrock topography) for an area that roughly coincides with the Antarctic continental shelf. The position of the merging line is individually chosen in different sectors in order to get the best out of each data set. High-resolution gridded data for ice shelf topography 10 and cavity geometry of the Amery, Fimbul, Filchner-Ronne, Larsen C and George VI Ice Shelves, and for Pine Island Glacier are carefully merged into the ambient ice and ocean topographies. Multibeam survey data for bathymetry in the former Larsen B cavity and the southeastern Bellingshausen Sea have been obtained from the data centers of Alfred Wegener Institute (AWI), British Antarctic Survey (BAS) and Lamont-Doherty 15 Earth Observatory (LDEO), gridded, and blended into the existing bathymetry map. The resulting global 1-min topography data set (RTopo-1) contains maps for upper and lower ice surface heights, bedrock topography, and consistent masks for open ocean, grounded ice, floating ice, and bare land surface. The data set is available in NetCDF format from the PANGAEA database at

From data collected by RV Polarstern, and additional echosoundings provided by national hydrographic offices, research institutions and the InternationalHydrographic Organization (IHO) Digital Bathymetric Data Center, the 1:1,000,000 Bathymetric Chart of the Weddell Sea (AWI BCWS) series has been developed. The heterogeneity of bathymetric data and the lack of observations for ice-covered areas required the incorporation of supplementary geophysical and geographical information. A new semi-automatic procedure was developed for terrain modeling and contouring. In coastal regions, adjacent sub-glacial information was included in order to model the bathymetry of the transition zone along the Antarctic ice edge. Six sheets of the AWI BCWS series in the scale of 1:1,000,000 covering the southern Weddell Sea from 66°S to 78°S and from 68°W to 0°E were recently completed and included in the 1997 GEneral Bathymetric Chart of the Oceans (GEBCO) Digital Atlas CD-ROM. On the basis of these six 1:1,000,000 AWI BCWS sheets, a generalized l:3,000,000-scale bathymetric chart was compiled for the entire southern Weddell Sea. That chart is included in this volume and is described with regard to its significance to other disciplines.

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