Detailing its findings at the 48th Lunar and Planetary Science Conference, the team thought that an asteroid incited 150-meter (492-feet) waves when it hit an ocean believed to have been on the northern part of ancient Mars. The crater, called Lomonosov and located in Mars’ northern plains, fits the characteristics of tsunami deposits on the surface.
Tsunamis And An Ancient Ocean
"We found typical tsunami deposits along the dichotomy between the northern hemisphere and southern hemisphere of Mars. It supports that there was, at that time, a northern ocean,” lead researcher and Université Paris-Sud professor Dr. François Costard said in a BBC News report.
It may not be a popular idea today, but some experts believe that an ocean might have once occupied the lowland section occupying Mars’ northerly latitudes. This new evidence involving tsunamis helps confirm this idea.
To test their proposal, the team identified and tracked the distribution of sediment that seemed to originate in the northern plains, as well as flowed onto a potential bygone shoreline to the south.
Two encouraging findings were lobate flow deposits (from a massive wave washing over plateaus and through valleys) and landforms called thumbprint terrain, making a case for sediment deposits as well as an ancient ocean.
The terrain was formerly interpreted as the result of mud flows, mud volcanoes, or glaciers. But the tsunami, traveling 95 miles and climbing to peaks of around 330 feet, need an ocean in the northern plains in order to have taken place.
The roughly 75-mile-wide Lomonosov crater, named after 18th-century scientist and polymath Mikhail Lomonosov, features a collapsed rim and a very degraded overall appearance.
It is thought to be created by the impact of a huge-scale, high-speed tsunami followed by a second wave that allowed it to reach the shoreline situated tens of miles from the said impact crater.
If it is true that an ocean existed on the red planet billions of years ago, it could have produced a more life-supporting Mars today. This further fuels hopes of finding signs of biology on the planet.
One can recall that last May, a study by a team from the Planetary Science Institute (PSI) in Arizona found signs of two mega tsunamis that may have occurred during Mars’ early formation.
The waves rose to around 400 feet in height and produced shore-break waves with 150-feet-tall waves at an average.
The team saw that the layers of dark, flat sediment on higher elevations were bordered by rock and boulder-filled exposures, which they believed was probably created by massive tsunamis. Incidentally, they also detected seven impact craters formed by meteors, also their leading culprit behind the huge wave formations.
Other scientists, however, disagreed, saying that current proof of water once flowing on the red planet came to life during the Noachian period or around 3.8 billion years old, before the PSI team thought Mars lost most of its water-friendly atmosphere.
The new findings were discussed in the Journal of Geophysical Research - Planets.