ETOPO1

ETOPO1 is a 1 arc-minute global relief model of Earth's surface that integrates land topography and ocean bathymetry. It was built from numerous global and regional data sets, and is available in "Ice Surface" (top of Antarctic and Greenland ice sheets) and "Bedrock" (base of the ice sheets) versions. ETOPO1 is available in two registrations: grid/node-registered: cells are centered on lines of latitude and longitude and cell/pixel-registered: cell edges are along lines of latitude and longitude. The grid-registered is the authoritative registration. The cell-registered is derived from the grid-registered, and the conversion produces slightly flattened relief.