Underground volcanoes could explain possible liquid water on Mars

The Martian South Pole, which measures about 12.5 miles across and is believed to hide a lake of liquid water beneath the ground. NASA

Scientists last year discovered that there could be liquid water on Mars, located beneath the polar ice cap, one mile from the surface of the planet. Now a different team of researchers has argued that for there to be liquid water, there must be an underground source of heat — and they believe that underground volcanoes could be responsible.

The new team from the Lunar and Planetary Laboratory at the University of Arizona, looked at what temperatures in the subsurface would be required for there to be liquid water beneath the polar ice cap. They did consider the role of salts that are present in the martian rocks, as these lower the melting point of ice, making liquid water possible at colder temperatures. But even with the presence of salts taken into consideration, they found that the conditions on Mars were too cold for there to be liquid water unless there was an undergrounds heat source.

A plausible heat source would be magma moving in the planet’s subsurface that rose up out of the deep interior and toward the surface around 300,000 years ago. Unlike an erupting volcano, when hot magma breaks through the surface of a planet, this magma did not break through and so it formed a magma pocket under the ground. The magma was so hot and cooled so slowly that heat from the chamber is still reaching the water beneath the ice cap today.

There is previous evidence of volcanic activity on Mars, but this study suggests that the activity could have taken place relatively recently and could even still be ongoing.

“This would imply that there is still active magma chamber formation going on in the interior of Mars today, and it is not just a cold, sort of dead place internally,” Ali Bramson, postdoctoral research associate and co-lead author of a paper on this theory said in a statement. “We think that if there is any life, it likely has to be protected in the subsurface from the radiation. If there are still magmatic processes active today, maybe they were more common in the recent past, and could supply more widespread basal melting. This could provide a more favorable environment for liquid water and thus, perhaps, life.”

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