Extensive Lava Flows from Arsia Mons. The flows that erupted from Arsia Mons extend some 1500 km away from the summit and bury the older cratered terrain of the southern hemisphere. Flows of this type associated with big volcanoes may have lengths in excess of 1000 km, and may resemble the large flows found in Mare Imbrium on the moon. The discovery of these flows on the outer flanks of the major volcanoes on Mars has shown that the basal diameter of many of these volcanoes is considerably larger than was suspected from Mariner 9 data. The image is about 240 km across.
North is to the upper right.