Mars: Northern hemisphere slopes and slope distributions

We investigate slope distributions in the northern hemisphere of Mars from topographic profiles collected by the Mars Orbiter Laser Altimeter. Analysis of the region from about 12°S to 82°N, over diverse geologic units, indicates that the range of regional-scale slopes is small, generally <3°. Surface smoothness is most distinctive in the vast northern hemisphere plains, where slopes are typically <1°. Amazonis Planitia is particularly remarkable in its smoothness, exhibiting an rms variation in topography of