SPACE -- October 4, 2013 at 10:41 AM ET
Martian craters could be ancient supervolcanoes that radically transformed the Red Planet
Scientists have found evidence suggesting Mars was pocketed by underground supervolcanoes. In a paper published in the journal Nature, Joseph Michalski of London's Natural History Museum and Jacob Bleacher of NASA's Goddard Space Flight Center hypothesize that Mars could have been home to supervolanoes, and these volcanoes' eruptions could have radically changed the environment of ancient Mars.
A fair amount is known about the 'typical' Marc volcanoes, which are mountain-shaped layers of lava, and resemble mountains in Hawaii. (A year ago, the Curiosity Rover even found that Martian soil was similar to Hawaiian volcanic dirt. A good example of this type of volcano is Olympus Mons, three times the size of Mt. Everest that steadily pumped out lava for billions of years. These newly hypothesized supervolanoes are nothing like that, instead blasting out hundreds of cubic miles worth of magma in eruptions thousands of times more powerful than the 1980 Mount St Helens blast. These "caldera" volcanoes are most similar to the supervolcano under Yellowstone National Park, a collapsed underground structure rather than a steep mountain.
The scientists reanalyzed satellite photos of the crater-speckled region of Arabia Terra and realized that the "impact craters" might instead be remnants of ancient volcanoes. Michalski believes that, just like Earth's climate, Mars' climate could have been shaped by supervolcanoes. The massive eruptions would have either caused the planet to undergo periods global warming, global cooling, or both, because of competing environmental processes.
"If future work shows that supervolcanoes were present more widely on ancient Mars, it would completely change estimates of how the atmosphere formed from volcanic gases, how sediments formed from volcanic ash and how habitable the surface might have been."
But this new hypothesis was met with skepticism by some scientists. Talking with NBC News, Shan de Silva, a volcanologist at Oregon State University, said the scientific community should be skeptical about finding Earth analogs for features on Mars.
I'm not convinced that these are volcanic. They're interesting features, but none of the criteria that they use to eliminate impact craters is definitive. If it's not volcanic, why are we even talking about this being a supervolcano?"
Regardless of the scientific debate, this new hypothesis presents an interesting new factor in Mars' development as a planet, one that might have radically changed how the planet looked billions of years ago.