Tsunamis from meteor impacts may have significantly altered Martian landscape

Science News : Although evidence suggests that Mars’s northern lowlands were covered by an ocean 3.4 billion years ago, critics point out the lack of shoreline features. Now Alexis Rodriguez of the Planetary Science Institute in Tucson, Arizona, and his colleagues believe that tsunamis from meteor impacts could have removed such features. Rodriguez’s team examined imagery of Mars’s surface and identified evidence of at least two tsunamis with wave heights up to 120 m that occurred a few million years apart. The researchers believe that the first tsunami explains the unusual locations of massive boulders and the presence of large backwash channels on the Martian surface. The second tsunami appears to have occurred after Mars’s atmosphere cooled, so the water displaced by the tsunami froze in place; Rodriguez says the ice formations could provide information about the chemical makeup of the ancient ocean. Confirming the tsunami theory would probably require an on-the-ground mission to examine various structures up close.