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A study found that the waters overflowing from ancient lakes on Mars created catastrophic floods that quickly dug canyons on the red planet.
The findings suggest that catastrophic geological processes may have played a major role in shaping the landscape of Mars and other worlds without plate tectonics, said Tim Goudge, postdoctoral researcher at the University of Texas at Austin in the USA.
"These lacerated lakes are quite common and some of them are quite big, others of the Caspian Sea," said Goudge, lead author of the study published in the journal Geology.
"So we think that this type of catastrophic overflow flooding and rapid incision of exit canyons was probably very important on the surface of Mars early," he said.
By studying rock formations from satellite images, scientists know that hundreds of craters on the surface of Mars were once filled with water.
More than 200 of these "paleolakes" have exit canyons of several tens to hundreds of kilometers long and several kilometers wide excavated by the waters coming from the old lakes.
However, it was not known if the canyons had been progressively dug over millions of years or quickly carved by a single flood.
Using high-resolution photos taken by NASA's Mars Reconnaissance Orbiter satellite, the researchers examined the topography of the crater's outlets and edges and highlighted a correlation between the size of the outfall and the volume of water likely to be released during a major flood.
If the landfill had instead been gradually reduced over time, the relationship between water volume and the size of the landfill would probably not be maintained, Goudge said.
In total, researchers examined 24 paleolakes and their canyons across the red planet. One of the paleolakes examined in this study, Jezero Crater, is a potential landing site for NASA's probe mission, March 2020, which looks for signs of past life.
The researchers proposed the crater as a landing site on the basis of previous studies that it would have retained water for long periods in the past of Mars.
While massive floods from Martian craters may seem like a scene in a science fiction novel, a similar process occurs on Earth as glacially barred lakes cross ice barriers.
They found that the similarity is more than superficial. As long as gravity is taken into account, floods create similarly shaped outlets, either on Earth or on Mars.
Although the great floods on Mars and the Earth are governed by the same mechanics, they are part of different geological paradigms. On Earth, the slow, steady movement of tectonic plates radically changes the surface of the planet in millions of years.
On the other hand, the absence of plate tectonics on Mars means that cataclysmic events, such as floods and asteroid impacts, quickly lead to changes that can lead to almost permanent landscape changes.
"The terrestrial landscape does not conserve large lakes for a very long time," said NASA scientist Caleb Fassett.
"But on Mars, these canyons have existed for 3.7 billion years, allowing us to better understand what the depth of surface water on Mars looked like," Fassett said.
(This story has not been changed by Business Standard staff and is generated automatically from a syndicated feed.)
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