This map shows Loire Vallis (white line), a canyon formed by water overflowing from a lake in Parana Basin (outlined in white). This is just one of many such valleys created by lake breach flooding on early Mars. Image via NASA/ GSFC/ JPL/ ASU/ PSI.
Billions of years ago, Mars was a land of lakes and rivers. Many old river valleys can still be seen today, a record of when Mars was a significantly wetter world. Now, scientists have found new clues as to just how some of those valleys formed: overflowing lakes.
According to a new study led by Timothy A. Goudge at the University of Texas, at least 25 percent of the valleys were created by lake breach flooding, where the water in the lakes overtopped their rims. This is similar to flood waters breaching and overtopping levees.
As a result, huge floods occurred, which carved out the valleys in the surrounding landscape.
The researchers published their peer-reviewed findings in Nature on September 29, 2021.
Land o’ Lakes
Lakes and rivers were abundant on early Mars, before the planet lost most of its atmosphere and warmth and became the cold, dry world we see today. This has been ...