Yellowstone's Volcanic Activity Is Changing

Those living in fear of a supervolcano eruption at Yellowstone National Park can breathe easy: The park may be sitting on a lot of magma, but there's no risk of a volcanic eruption in our lifetimes, according to a new study. Researchers employed magnetotellurics, a remote sensing technique, to look at the magma formations beneath the park, ranging between 1,247 degrees and 2,512 degrees, per USA Today. They found volcanic activity is shifting to the northeast as the North American tectonic plate over the Yellowstone hotspot continues to shift southwest. But because the magma below Yellowstone is stored in separate reservoirs, it is not concentrated enough to trigger an eruption, at least not anytime soon.

Basaltic magma, commonly produced by direct melting of the Earth's mantle, is responsible for most volcanic activity on Earth. It flows easily. But Yellowstone's basaltic magma is so deeply buried in the Earth's crust that it's unlikely to trigger an eruption within our lifetimes, researchers say, per the Washington Post. In the Earth's upper crust below Yellowstone is another type of magma, silica-rich rhyolitic magma, which is much thicker than basaltic magma and more resistant to flow, reports the Post. It tends to "erupt explosively," according to the US Geological Survey. But it's "stored in segregated regions beneath the caldera with low melt fractions," meaning a low radio of magma to total volume of crust, "indicating that the reservoirs are not eruptible," according to the study published Wednesday in Nature.

"By no means is Yellowstone 'due for an eruption,'" concludes Erik Klemetti Gonzalez, a Denison University researcher unaffiliated with the study, per the Post, noting the next eruption could be "thousands of years" away. USGS volcano geophysicist Ninfa Bennington, lead author of the Nature study, notes it could take hundreds of thousands of years for enough magma to fill Yellowstone's various concealed reservoirs for an eruption to be likely. And "it would be difficult to mobilize into a single eruption because they're not connected," Bennington tells USA Today of the reservoirs. (More Yellowstone National Park stories.)