CIPS Seminar

Putative paleo-shorelines in the northern plains of Mars have been used as evidence of an early Martian ocean. However, the shorelines deviate in elevation from an equipotential (by up to several kilometers), which has been used to challenge the notion that they formed via (and the existence of) an early ocean. We show that long-wavelength variations in shoreline topography can be explained by deformation due to the emplacement of Tharsis, a volcanic province that dominates the gravity and topography of Mars. Our results imply that oceans on Mars formed early, and point to a close relationship between the evolution of oceans on Mars and Tharsis volcanism, with broad implications for the geology, hydrological cycle, and climate of early Mars.