OCEAN, ICE, AND ATMOSPHERE: INTERACTIONS AT THE ANTARCTIC CONTINENTAL MARGIN ANTARCTIC RESEARCH SERIES, VOLUME 75, PAGES 371-380 THE NEW BATHYMETRIC CHARTS OF THE WEDDELL SEA: AWIBCWS Hans Werner Schenke, Semme Dijkstra, Fred Niederjasper, and Tilo Schone Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany Heinrich Hinze Geoddsie & Meer, Meine, Germany Bernd Hoppman Media Factory, Bremerhaven, Germany From data collected by RV Polarstern, and additional echosoundings provided by national hydrographic offices, research institutions and the International Hydrographic 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. 1. INTRODUCTION Much of the Weddell Sea is covered with multi- year sea ice, and hence is difficult to traverse. The available bathymetric data is patchy, varying in type, source, and quality. Various approaches for mapping its bathymetry have been used in the past. The compi- lation of GEBCO Sheet 5.18 was carried out by John- son and Vanney in 1980, and GEBCO Sheet 5.16 was compiled and contoured by C. Brenner, assisted by F. Mouzo, in 1981 under the scientific coordination of J. LaBrecque and P. Rabinowitz. Due to different inter- pretations of the available data, manual contouring has led to significant differences, especially in the northern Weddell Sea. In the southern Weddell Sea the areas adjacent to the ice shelves are of particular interest, as they are topographic controls on the circulation of Antarctic Bottom Water. The Weddell Sea and the southern Atlantic Ocean comprise the main working area of RV Polarstern which began operations in 1983. Since that time large amounts of bathymetric data have been collected on more than 40 expeditions in these regions. Few data other than those collected by RV Polarstern are avail- able for the western, central, and southern part of the Weddell Sea, GEBCO Sheet 5.16 therefore was chosen by us as a test-case for a new compilation to update GEBCO to its Sixth Edition. Within the framework of a research and development program at the Alfred Wegener Institute (AWI), all available bathymetric data in this region were collected, compiled, and ana- lyzed. A number of new techniques were developed and applied by AWI for this purpose, resulting in Copyright 1998 by the American Geophysical Union 371