[Z, refvec] = etopo('etopo1_ice_c_i2.bin', samplefactor);
geoshow(Z, refvec, 'DisplayType', 'surface');
setm(gca,'mapprojection','mercator');
cmap = cmocean(flipud('deep'),'5');
demcmap(Z, 256, cmap, [.25 .25 .25]);
colorbar;
c = colorbar
title(c,'m','FontSize',12);
set(c, 'ylim', [-10000 0]);