Mars: The Origin of Megafloods on the Red Planet
What causes Martian megafloods? Scientists may have a new hypothesis. They've put forward that enormous discharges of subterranean water may have dug out the biggest flood channels in the solar system over 3 billion years ago.
For many years, researchers believed these megafloods were caused by the release of a deep global hydrosphere in the Martian subsoil. However, new research has revealed that their origin could have been vast quantities of sediment and ice deposited about 450 million years before the floods.
Sediments, carried by rivers and glaciers on Mars, may have filled up enormous canyons below an ancient ocean located in the Northern Lowlands. The release of this water trapped in these buries sediments may have caused the megafloods, whose effects we can observe in the present.
So how did this work? The canyons filled up, the ocean disappeared and the planet surface remained frozen for about 450 million years. Then, about 3,200 million years ago, the heat from lava beneath the canyons thawed the ice trapped in the sediments and enormous rivers of subterranean water spread over hundreds of kilometers before eventually bursting out on to the now-dry surface and causing the megafloods.
"Our research suggests that, given that the process was regional rather than global, there could still be large reservoirs of subterranean water trapped under the surface of Mars, in the areas around the old northern ocean, or in other parts of the planet where seas and lakes formed at the same time," write the researchers, in a news release. "Traces of ancient environments capable of sustaining life forms similar to those on Earth could have been preserved in sub-surface materials that are now exposed."
The findings are published in the journal Scientific Reports.
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