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Super volcanic eruptions have regularly torn the surface of March billions of years ago, altering the planet’s climate for decades and creating scars that are still visible today, a new study has found.
A team of American geologists has found evidence that the large craters visible in satellite images of the Arabia Terra region of northern Mars were not created by asteroids, as some had originally believed, but by massive volcanic eruptions that could throw billions of tons of gas and molten rock into the atmosphere.
Better known as calderas, these craters are essentially the remnants of once powerful explosive super volcanoes, and they have more irregular shapes than their asteroid-created counterparts. But given that these powerful eruptions would have occurred around 4 billion years ago, finding conclusive evidence as to their nature required rather forensic methods.
Related: Why this explosive Mars-like volcanic island fascinates NASA
Scientists looked for traces of volcanic ash and modeled how it would disperse after such eruptions and where it would settle. Then they looked at high-resolution images taken by NASA Mars Reconnaissance Orbiter to see if the models matched their expectations.
“At that point we said, ‘OK, well, these are minerals associated with weathered volcanic ash, which has already been documented, so now we’re going to look at how the minerals are distributed to see if they follow the pattern we would expect to see super eruptions, ”said Alexandra Matiella Novak, study co-author, a volcanologist at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. in a report. The new research builds on previous studies by Matiella Novak of volcanic ash deposits in other regions of Mars.
What the researchers found in the pictures matched the patterns. The ashes spread downwind, east of the seven calderas revealed in the images of the Mars Reconnaissance Orbiter. The deposited ash was traceable thousands of miles from the craters, with the layer thinning further from the source.
“We’re actually seeing what’s been predicted, and it’s been the most exciting moment for me,” said study co-author Jacob Richardson, a geologist at NASA’s Goddard Space Center in Greenbelt, Md., In. the press release.
The supervolcanoes, probably active for a period of 500 million years around 4 billion years ago, have spewed massive amounts of water vapor, carbon dioxide and sulfur dioxide into the atmosphere of Mars. , unbalancing the planet’s climate for decades.
“Each of these eruptions would have had a significant climate impact – perhaps the gas released made the atmosphere thicker or blocked the sun and made the atmosphere cooler,” the lead author said. study, Patrick Whelley, geologist at NASA Goddard, in the statement. “Martian climate modellers will have work to do in trying to understand the impact of volcanoes.”
The last supervolcano eruption on Earth took place 76,000 years ago in Sumatra, Indonesia. But the terrestrial calderas, tens of kilometers wide, are spread around the world in tectonically known regions, where the majority of smaller but still active volcanoes also reside.
The odd thing about the Martian Arabia Terra, however, is the fact that it doesn’t show traces of smaller volcanoes.
Scientists speculate that the calderas on Earth may have been eroded over billions of years or moved around the globe with the changing continents. These types of explosive volcanoes could also exist in regions of the moon of Jupiter Io or could have been grouped on Venus, says the scientist.
Earlier this year, scientists at the Planetary Science Institute in Tucson, Ariz., Found evidence that Mars could still be volcanically active today. However, most of the volcanic activity on the Red Planet occurred during the time of the supervolcanoes, around 4 billion years ago. Mars at 13.6 miles above sea level (21.9 km) Olympus Mons, the largest volcano in the solar system, is said to have last erupted around 25 million years ago.
The study was published in the journal Geophysical Research Letters in July 2021.
Follow Tereza Pultarova on Twitter @TerezaPultarova. Follow us on Twitter @Spacedotcom and on Facebook.
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