Monster tsunamis caused by meteor impacts swept across the northern plains of Mars more than three billion years ago, radically resculpting the edges of the Red Planet’s ancient seas, according to a study published Thursday.
The findings, based on geological mapping, could provide new clues in the search for life.
They also bolster the theory that massive floods 3.4 billion years ago transformed Mars’ northern lowlands into a sprawling ocean, the study said.
Some scientists had challenged that notion, pointing out that the alleged shoreline of this long-gone sea is today ragged and uneven — not a landscape one would expect to find ringing an ocean.
“Our discoveries reconcile the ocean hypothesis with the puzzling absence of shorelines distributed along a constant elevation,” lead author Alexis Rodriguez, a researcher at the Planetary Science Institute in Tucson, Arizona, told AFP.
These mega-tsunamis probably numbered in the dozens over hundreds of millions of years , but the study, published in Nature’s Scientific Reports, focused on two that happened a few The researchers suggested that the Martian lobes were caused by two giant tsunamis, which extended over a wide range of elevations, from gently sloping plains to cratered highlands. The older tsunami inundated an area about 309,000 square miles (800,000 square kilometers) in size, while the younger one drowned a region about 386,000 square miles (1 million sq. km) large, the researchers said.