Using Topography in GMT

If the topography is available as a *.grd file, it can be plotted like this:

makecpt -Ctopo > topo.cpt
grdimage etopo2.grd -JW0/25 -Rg -Ei -Sn- -Q -Ctopo.cpt -K
pscoast -JW0/25 -Rg -Dc -W0.25p -A0/0/1 -O