Megafloods shaped Martian surface, says study
Though Mars appears totally dry today. Craters filled with water were present on Martian surface billions of years ago. Water overflowing from these crater altered many features of Martian geology
Mars, the nearest neighbour of Earth is today a barren wasteland. The red planet is a striking sight in the night sky. It's hard to imagine anything catastrophic happening on Mars today.
But a new study has found that massive floods from overflowing craters had outsized role in shaping Martian surface. The study has been carried out by researchers at University of Texas at Austin.
The study found that these floods carved deep chasms and moved vast amounts of sediment. The findings have been published in the scientific journal 'Nature'
"If we think about how sediment was being moved across the landscape on ancient Mars, lake breach floods were a really important process globally," said lead author Tim Goudge, an assistant professor at the UT Jackson School of Geosciences.
"And this is a bit of a surprising result because they`ve been thought of as one-off anomalies for so long," Goudge added.
Crater lakes were common on Mars billions of years ago when the Red Planet had liquid water on its surface. Some craters could hold a small sea`s worth of water. But when the water became too much to hold, it would breach the edge of the crater, causing catastrophic flooding that carved river valleys in its wake.
A 2019 study led by Goudge determined that these events happened rapidly. Remote sensing images taken by satellites orbiting Mars have allowed scientists to study the remains of breached Martian crater lakes.
However, the crater lakes and their river valleys have mostly been studied on an individual basis, Goudge said. This is the first study to investigate how the 262 breached lakes across the Red Planet shaped the Martian surface as a whole.
The research entailed reviewing a preexisting catalogue of river valleys on Mars and classifying the valleys into two categories: valleys that got their start at a crater`s edge, which indicates they formed during a lake breach flood, and valleys that formed elsewhere on the landscape, which suggests a more gradual formation over time.
From there, the scientists compared the depth, length and volume of the different valley types and found that river valleys formed by crater lake breaches punch far above their weight, eroding away nearly a quarter of the Red Planet`s river valley volume despite making up only 3 per cent of total valley length.
(With inputs from agencies)