The USGS explosive volcanoes expert predicted that the Yellowstone supervolcano is likely to erupt unleashing as much as 1,000 cubic km of ash because of previous supereruptions in the area.
Dr Mastin cited three previous eruptions as evidence renewed explosive activity from the US national park volcano is “likely” in the future – but insisted that forecasting a time frame would be difficult as eruptions are not strictly “periodical.”
Speaking to Coast to Coast AM, the volcanologist said: “Yellowstone lies at the northeastern end of a long chain of major volcanoes that have produced super eruptions for a period going back at least 15 million years. So it seems likely that there will be more supereruptions in Yellowstone.
“It’s hard to say it is overdue , it’s not really periodic enough to say ‘ok, we should be having one anytime,’ and if you look at the activity going on at the caldera right now in terms of seismic activity it’s basically doing what it has been doing for the last few decades.”
The USGS said it does not know when Yellowstone will erupt but deep volcanic activity, caldera uplift and frequent earthquakes are all reminders the supervolcano is far from being dormant.
By some estimates, the US might have to wait for another one or two million years before the supervolcano finally blows.
Dr Mastin continued: “There was a very large eruption about 2.1 million years ago. There was a super eruption about 1.2 million years ago. A supereruption basically is the largest class of explosive eruptions on Earth. They are eruptions that expel more than 1,000 cubic km of ash.
“Then the most recent of this supereruptions at Yellowstone was about 600,000 years ago so there’s been three in the past 2.1 million years. But it’s hard to say it is overdue , it’s not really periodic enough to say ‘ok, we should be having one anytime,’ and if you look at the activity going on at the caldera right now in terms of seismic activity it’s basically doing what it has been doing for the last few decades.”
A Yellowstone volcano eruption could prove destructive for the Western half of the States as it could cover crops in the midwest with at least 4 inches of ash. It would spout dangerous gases such as sulfur dioxide leading to acid rain and global cooling.
Yellowstone National Park is found in the northwest of the United States, spread across the corners of Wyoming, Idaho and Montana.
Since that last “caldera-forming” super-eruption 640,000 year ago, the USGS has recorded at least 80 nonexplosive events.
The USGS said: “Of these eruptions, at least 27 where rhyolite lava flows in the caldera, 13 were rhyolite lava flows outside the caldera and 40 were basalt vents outside the caldera.
“Some of the eruptions were approximately the size of the devastating 1991 Pinatubo eruption in the Philippines, and several were much larger.
“The most recent volcanic eruption at Yellowstone, a lava flow on the Pitchstone Plateau, occurred 70,000 years ago.”