etopo2_8bit.sid: Global bathymetry image (MrSid format)

The National Geophysical Data Center assembled a 2-minute gridded database of global releif data, referred to as ETOPO2. The seafloor data between latitudes 64° North and 72° South are from the work of Smith and Sandwell (1997). These data were derived from satellite altimetry observations combined with carefully, quality-assured shipboard echo-sounding measurements, by Dr. Walter H.F. Smith, of the NOAA Laboratory for Satellite Altimetry and Dr. David T. Sandwell, of the Institute of Geophysics and Planetary Physics at the University of California, San Diego. This dataset formed the basis for the creating of the bathymetry image for this product's GIS.