Scientists have revealed that powerful supervolcanoes once covered the surface of Mars and could help explain the planet's mysterious internal and atmospheric history, the Los Angeles Times reported on October 2.
Supervolcano is an informal term used to describe an immense eruptive event that expels a significant amount of rock and ash. According to BBC News, Earth has experienced supervolcanoes in the past as well, but not for thousands of years. However, Yellowstone National Park currently sits atop an old supervolcano.
Joseph R. Michalski and Jacob E. Bleacher, the two scientists involved with the study, have published their findings in this week's issue of Nature. Michalski and Bleacher say that the gases released from the volcanoes would have influenced the make-up of the atmosphere and ashfall from eruptions would have covered large expanses of Mars. Michalski explained the implications of the study in a press release.
Scientists know the planet must have been more active in its deep past, in its first billion years. But we've always struggled to find evidence for these early volcanoes. The supervolcanoes we report in Nature may solve this puzzle.
Despite their cataclysmic power, supervolcanoes are difficult to identify. Unlike volcanoes like St. Helens or the Olympus Mons volcano on Mars, supervolcanoes do not build mountains out of layers of lava. The power of a supervolcanoe eruption is so strong that it creates a large bowl, or caldera, in the landscape. Michalski and Bleacher believe they have identified a number of potential supervolcano sites on the surface of Mars, specifically in norther hemisphere of the planet, known as Arabia Terra. The scientists have said that is unlikely the calderas they have discovered are old meteor impact sites because they are irregular in shape and lack the characteristics typical of meteor craters.
Gases released from the supervolcanoes on Mars would have influenced the composition of the atmosphere in addition to having an impact on Mars' potential for habitability as the volcanoes would have brought large quantities of water and other essential elements needed to sustain life to the surface of the planet.
Michalski has said that if future research shows evidence of more supervolcanoes, it will completely change estimates of how Mars' atmosphere formed from volcanic gases and just how habitable the surface of the planet might have been.
