Had you been there, said Michalski, you would have been standing around in Wyoming and observing a bit of steam coming out of the ground. You would start to feel earthquakes because of the movement of magma underneath you, causing the earth to crack and break.
Bigger and bigger earthquakes would have given way to smaller explosions from within the ground. That happens because as the magma produces bubbles, pressure would build up and blows up the terrain; destabilization would lead to more earthquakes and then — boom! — a massive explosion.
Such explosions would send ash far into the atmosphere, creating lots of heat and gas. The wind would carry away the ash, and while much of it would rain down to form layered materials on Earth, some ash would stay in the atmosphere for years to come
“By the time you’d get to see that, you’ll be dead, because it’s quite a massive, violent activity,” Michalski said. “No one’s really ever witnessed it, because if you did, you wouldn’t be here to tell about it.”
Why it matters
Supervolcanoes were instrumental in shaping geological formations and the climate on our own planet, and the same goes for Mars, Michalski said.
Eruptions would have sent the climate into a tailspin of global cooling or warming, or both, because of competing environmental processes, he said. The volcanic explosions emitted greenhouse gas and unleashed ash into the atmosphere, which blocks out the sun.
“That would have had a strong impact on what the climate and what the environment was like at geologically relevant time scales,” he said.
Understanding supervolcanoes could give scientists new clues into the early Martian atmosphere and explain various features of the planet’s geology. Material from the eruptions may even be responsible for some of the rocks that the Mars rover Curiosity has been encountering since it landed on August 6, 2012.
Mars may be home to even more ancient supervolcanoes that today look like impact craters, researchers say.
Stephanie C. Werner, planetology researcher at the University of Oslo, who was not involved in the study, believes some of the conclusions of this new study are speculative and not based on a firm timescale. More research is needed to better determine whether this supervolcano activity really predates other significant volcanic episodes, specifically, those that occurred in the Tharsis region of Mars, she said.
“One thing lacking in this study is the constraint on the timing of these events, to fully evaluate the impact on atmosphere evolution and impact on climate,” she said in an e-mail. “Nonetheless, events related to the formation of these landforms can have significant influence and may be important if no other activity occurred at the same time.”
More orbital data would help resolve unanswered questions about the ancient supervolcanoes, Michalski said.
Like magma under an active fault, such discussions will continue bubbling among members of the community of scientists who study Mars.
Elizabeth Landau | CNN