Floods From Overflowing Crater Lakes Sculpted The Martian Surface

Scientists have long said that the surface of Mars shows a significant presence of water in its distant past. A new study conducted by UT Austin has found that massive floods from overflowing crater lakes played a significant role in shaping the planet's surface we know today. The team believes the flooding carved deep rifts into the surface and moved massive amounts of sediment.Researchers believe the flooding on Mars probably lasted only weeks but eroded enough sediment to fill Lake Superior and Lake Ontario. Study lead author Tim Goudge says that when considering how sediment moved across the landscape on Mars, lake breach floods are an important part of the global process. Billions of years ago, crater lakes were common on Mars, and some were large enough to hold enough water to create a small sea.

However, when the craters became overfilled, the water would breach the edge leading to catastrophic levels of flooding. The previous study determined these flooding events happened rapidly. Satellites orbiting the Red Planet have allowed scientists to study the remains of breached crater lakes.

The project split a pre-existing catalog of river valleys into two categories. The categories included valleys that start at a crater's edge indicating formation from a breach flood, and valleys that formed on other parts of the landscape, suggesting gradual formation over time. Scientists determined crater lake breaches eroded nearly a quarter of the river valley volume on Mars while making up only three percent of the total valley length.

Researchers also determined that the median depth of breached river valleys on the Red Planet is 559 feet, more than twice as deep as valleys created over time with the median depth of 254 feet. Scientists also believe that crater breach river valleys formed quickly enough to have a long-lasting impact on the landscape around them. The depth of the breaches created canyons that could've influenced the formation of other nearby river valleys.