Giant waves, possibly triggered by two meteorite impacts, may have shaped Mars’s coastline and could hint at whether the red planet was once habitable.

An artist’s impression of the ancient ocean on Mars. Illustration: Nasa/GSFC/Rex

By Nicola Davis

Mega-tsunamis in an ancient ocean on Mars may have shaped the landscape and left deposits that hint at whether the planet was once habitable, researchers say.

The giant waves, thought to have reached up to 120 metres in height as they raced over the land, could have been triggered by two large meteorites slamming into the surface.

The tsunamis may been powerful enough to shape much of the ancient coastlines on Mars, said J. Alexis Palmero Rodriguez, of the Planetary Science Institute in Tucson, Arizona, who led the study.

Writing in the journal Scientific Reports, the international team, which included scientists from the US, China and Germany, describe how they set out to probe a Martian mystery.

It has previously been proposed that the lowlands of the northern hemisphere of Mars were catastrophically flooded around 3.4 billion years ago, forming a vast ocean, potentially covering several million square kilometres. But scientists have been puzzled by the lack of an associated shoreline and its expected features.

Now Rodriguez and his team think they may have the answer- the fact that it is hard to make out such ancient shorelines is because huge tsunamis buried them, depositing sediments up to hundreds of kilometres inland.

Left: Researchers have created a digital elevation model of the area studied, showing the two proposed shoreline levels of an early Mars ocean that existed approximately 3.4 billion years ago. Right: Areas covered by the tsunamis. Photograph: Alexis Rodriguez

The Guardian

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Tags: ancient Martian oceans, Mars, tsunamis