Massive tsunami caused by the impact of meteors swept the northern plains of Mars more than three billion years, radically carving the edges of the ancient seas of the Red Planet, according to a study published Thursday. Also support the theory that large-scale floods that had occurred 3.4 billion years have transformed the northern valleys of Mars in a vast ocean, said the study. Some scientists have challenged this idea, pointing out that the estimated shoreline of this sea long gone today is uneven and bumpy – not the scenario we would expect to find around an ocean. “Our findings reconcile the ocean hypothesis with the puzzling absence of shorelines distributed along a steady rise,” said the study’s lead author, Alexis Rodriguez, researcher at the Planetary Science Institute in Tucson, Arizona.
These mega-tsunamis probably occurred to dozens over hundreds of millions of years, but the study, published in the ‘Scientific Reports’ of the journal Nature, focused on two that occurred with an interval of a few million years. The first dragged boulders and debris to land, tens or perhaps even hundreds of kilometers from the coast. The second took place over a much colder period, shooting over long distances huge blocks of ice, when the waves froze in midair.
The giant waves have been on average about 50 meters in height, but are likely to have high 120 meters – the equivalent of a 30-story building – when they reached the coast and invaded land. The investigator said that Mars is surely the most investigated planet of the solar system (besides Earth), and yet nobody seems to have noticed the evidence of giant waves on the Red Planet in the past.
Having originally been in liquid form, despite the sharp negative temperatures, the water should be very dense and salty. “It is known that aqueous and salted icy areas are habitable Earth and consequently some of the tsunami deposits may be the primary astrobiological targets,” said co-author Alberto Fairen, researcher at the Centre for Astrobiology Spain.