Giant tsunamis might have shaped the ancient Martian landscape

The waves of change.

While many researchers agree that Mars, the now arid Red Planet, was once covered in bodies of water, there is little evidence of shorelines left on its surface. Surely, if there were oceans, there were coasts. So where did they all go?

Well, a new study suggests that these coastal markings are hard to spot because huge tsunamis destroyed them some 3.4 billion years ago.

According to the US-based team, which was led by Alexis Rodriguez from the Planetary Science Institute in Arizona, large meteor impacts sent tremendous waves across the Martian landscape billions of years ago. These waves had the power to wash away the geological markings that researchers typically associate with coastlines by covering them with sediment and debris.

These waves were of an unimaginable size, too. As Thomas Sumner reports for Science News, meteor impacts on Mars were strong enough to generate 120-metre (393-foot) waves, which could flood up to one million square kilometres (386,000 square miles) of area. That’s about the combined size of Texas and California!

To make matters worse, these giant tsunamis probably happened roughly every 2.7 million years, based off of the rate the planet was struck with large meteors.

Using satellite data to examine displaced sediment on the Martian surface, the team was able to analyse two of these suspected tsunamis that happened roughly 3.4 billion years ago.

The first one was able to carry off huge boulders into weird areas where they do not belong on the surface. The second, which the satellite images suggest happened a few million years after the first, occurred after Mars’ climate cooled. This means that it sent water flying into odd places where it then froze, creating strange formations.

Basically, the Martian landscape doesn’t make a lot of sense to researchers because things are often out of place. There are boulders where there shouldn’t be boulders and sediment is strewn all about. The team says tsunamis are the only way these characteristics could have formed.

Outside researchers seemingly agree with the team’s findings because they’re quite logical, though the only way to know more about them is to visit the areas pinpointed by the team, which isn’t going to happen anytime soon.

Hopefully, the team will one day get the chance to explore the surface of Mars in person to add additional detail to their study. Until then, satellites will have to do.