The Martian Landscape Was Shaped by Massive, Climate Change–Fueled Floods

When the Red Planet’s lakes burst their banks, the disaster carved the undulating canyons and valleys we still see today

Loire Vallis (white line) is an outlet canyon that formed from the overflow of a lake in Parana Basin (outlined in white). Black lines indicate other valleys formed by processes other than lake overflows.
Image description via the Plantetary Science Institute: "Loire Vallis (white line) is an outlet canyon that formed from the overflow of a lake in Parana Basin (outlined in white). Black lines indicate other valleys formed by processes other than lake overflows. Background is colored MOLA-derived topography over a THEMIS image mosaic. Image is approximately 650 kilometers across." NASA/GSFC/JPL/ASU

Along with that iconic red dust, the planet Mars is covered by a dramatic topography, including the solar system’s highest mountain, countless impact craters and large series of canyons and valleys. Now, new research theorizes that some of those gorges could have been carved out of the Martian landscape by enormous floods as climate change melted the planet’s glaciers, according to a paper published last week in the journal Nature.

Mars is famously dry and dusty today, but billions of years ago the planet likely hosted a thick atmosphere and large amounts of liquid water. While research about whether that wet, warm Mars hosted life is still ongoing, it’s also increasingly clear that the effects of that time period can still be found deeply etched on the planet’s surface in the present day.

The wet Mars of yore was also one under regular bombardment by asteroids, and it’s likely that the craters caused by these impacts became lakes filled with water, reports Charles Q. Choi of Space.com. As climate change began to spiral out of control on the Red Planet, these lakes appear to have breached, releasing large amounts of water across the planet’s surface.

The magnitude is striking—the researchers estimate that up to 25 percent of the volume of Martian valleys was eroded by these lake breach floods, according to a statement released by the Planetary Science Institute.

While it was previously hypothesized that a relatively small amount of lake flooding had occurred on Mars, with the majority of its surface shaped by flowing rivers, this new research suggests that these overflowing lakes were the cause of more than 13,000 cubic miles of volume being carved away, a total ten times larger than Lake Michigan, per Space.com.

"Our finding that approximately one-quarter of the valley volume on Mars was carved geologically rapidly — on the order of days to months to years, as opposed to over tens to hundreds of thousands of years — was indeed quite surprising," geological scientist Timothy Goudge, who was lead scientist on the research, told Space.com.

This kind of devastating flooding has a close parallel to our planet. At the end of the last Ice Age, lakes held back by melting glaciers in the United States Pacific Northwest burst their banks, unleashing torrents of water that left their marks on the landscape.

And the parallels unfortunately still resonate today, reports Eric Mack of CNET. In mountain ranges such as the Himalayas and the Andes, melting glaciers are creating and filling large lakes that could eventually burst their banks and cause devastating floods. While it’s unlikely that their impacts will be on the order of the Martian lake floods, it’s clear that climate change could continue to shape the landscape on Earth in the future.