Is Tharsis Rise, Mars, a spreading volcano?

A theoretical similarity derived for spreading volcanoes remains valid for over three orders of magnitude in size, from small slumping volcanoes to large ocean plates. This similarity means that Mount Etna, Sicily, can be used as a terrestrial analogue of Tharsis Rise on Mars. A quantitative comparison of surface structures suggests that Tharsis has been spreading outward as a result of movement of plates at a planetary scale, producing rifting through the summit of the Rise, folding around its periphery, and with radial tear-fault systems connecting the summit rifts to the basal folds. The tear-fault systems form the fossae, of...