An Evaluation of Publicly Available Global Bathymetry Grids

Issue Title: The GEBCO (General Bathymetric Chart of the Oceans) Centennial Celebration 1903-2003 We evaluate the strengths and weaknesses of six publicly available global bathymetry grids: DBDB2 (Digital Bathymetric Data Base; an ongoing project of the Naval Research Laboratory), ETOPO2 (Earth Topography; National Geophysical Data Center, 2001, ETOPO2 Global 2' Elevations [CD-ROM]. Boulder, Colorado, USA: U.S. Department of Commerce, National Oceanic and Atmospheric Administration), GEBCO (General Bathymetric Charts of the Oceans; British Oceanographic Data Centre, 2003, Centenary Edition of the GEBCO Digital Atlas [CD-ROM] Published on behalf of the Intergovernmental Oceanographic Commission and the International Hydrographic Organization Liverpool, UK), GINA (Geographic Information Network of Alaska; Lindquist et al., 2004), Smith and Sandwell (1997), and S2004 (Smith, unpublished). The Smith and Sandwell grid, derived from satellite altimetry and ship data combined, provides high resolution mapping of the seafloor, even in remote regions. DBDB2, ETOPO2, GINA, and S2004 merge additional datasets with the Smith and Sandwell grid; but moving from a pixel to grid registration attenuates short wavelengths (