... The areas between the contours were measured automatically. The results of the measurement are represented on fig.1 The graphic shows the distribution of the height levels against their areas. ... USGS, USA Fig.1 The dependence of the distribution of the heights levels versus the area occupied Fig.2 The distribution of the areas of heights levels in the northern and southern hemispheres Fig.3 The distributions of the areas heights levels in eastern and western hemispheres of Mars ...