SRTM15_PLUS Estimated Topography, 15 seconds, Global, v1
One GMT file, topo15.grd, with the entire global topography. The grid resolution is 15 seconds which is roughly 0.27km at the equator. The data are pixel registered.

Land data are based on the 1-km averages of topography derived from the USGS SRTM30 grided DEM data product created with data from the NASA Shuttle …