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Abundant crater lakes chopped canyons over Mars

Jezero crater is a paleolake and potential landing site for NASA's March 2020 rover mission to look for past lives.…



Jezero crater is a paleolake and potential landing site for NASA’s March 2020 rover mission to look for past lives. The discharge channel flooded by flooding is visible on the upper right side of the crater. The inlets on the right side are cut by old rivers. Credit: NASA / Tim Goudge.

Today, most of the water on Mars is locked in frozen ice cubes. But billions of years ago it flowed freely across the surface and formed rushing rivers that emptied into craters, forming lakes and seas. New research led by the University of Texas in Austin has found evidence that sometimes the lakes would absorb as much water as they overflowed and blasted from their pools, creating catastrophic floods that snatched beautiful canyons very quickly, maybe in a few weeks.

The findings suggest that catastrophic geological processes may have had a major role in shaping Mars and other worlds with flat tectonics, “said lead author Tim Goudge, a postdoctoral researcher at the UT Jackson School of Geosciences who will start as a deputy professor at school in 201

9.

“These broken lakes are quite common and some of them are quite large, some as big as the Caspian Sea,” says Goudge. “So, we think that this kind of catastrophic flood flow and rapid intersection of the outlet hall were probably quite important on the early Mars surface.”

The research was published on November 16th in the journal Geology . Co-author is NASA researcher Caleb Fassett and Jackson School Professor and Associate Dean of Research David Mohrig.

From studying rock formations from satellite imagery, scientists know that hundreds of craters across the Mars surface once filled with water. More than 200 of these “paleolakes” have outlet cannons tens of hundreds of kilometers long and several kilometers wide shed of water flowing from the old lakes.

However, until this study, it was not known if the canyons were gradually shed over millions of years or carved quickly through individual floods.



The Palouse River Canyon is part of Channeled Scablands, a geological feature of east Washington that was shattered by catastrophic floods during the recent Ice Age. Researchers found that large floods on Mars and Earth cut the country in a similar manner. Credit: Keith Ewing

Using high resolution images taken by NASA’s Mars Reconnaissance Orbiter satellite, researchers investigated the topography of the outlet and crater rims and found a correlation between the outlet size and the volume of water expected to be released during a major flood event. If the outlet was instead gradually decayed over time, the ratio of water volume to outlet size probably would not hold, Goudge said.

In total, the researchers reviewed 24 paleolakes and their outlet cannons over the Red Planet. One of the paleolakes investigated in the study, Jezero Crater, is a potential landing site for NASA’s Mars 2020 rover mission to look for signs of past lives. Goudge and Fassett suggested the crater as a landing site based on previous studies that showed that it held water for long periods in the March past.

While massive floods flowing from marbles can sound like a scene in a science fiction novel, a similar process occurs on Earth when lakes dammed by glaciers break through their odd barriers. The researchers found that the similarity is more than shallow. As long as the gravity is reported, floods create drains of similar shapes, whether they are on Earth or Mars.

“This tells us that things that differ between the planets are not as important as the basic physics of the overflow process and the size of the container,” said Goudge. “You can learn more about this process by comparing different planets as opposed to just thinking about what’s happening on Earth or what’s happening on Mars.”

Although large floods on Mars and Earth are controlled by the same mechanics, they fit into different geological paradigms. On earth, the slow and evenest movement of tectonic plates dramatically changes the planet’s surface over millions of years. In contrast, the lack of flat tonics on Mars means that catastrophic events, such as floods and asteroid affairs, quickly create changes that can cause close permanent changes in the landscape.

“The landscape on Earth does not preserve vast lakes for a very long time,” said Fassett. “But on Mars … these canyons have been there for 3.7 billion years, a very long time, and it gives us insight into what The surface of the deep time was like Mars. “


Explore further:
Groundwater and precipitation gave water to form Greece’s Basin lakes through Mars history

Journal Reference:
Geology

Provided by:
University of Texas, Austin

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