Yellowstone volcano super-eruptions appear to involve multiple explosive events

The last super-eruption at Yellowstone volcano, which occurred 631,000 years ago, was not one huge explosion. Instead, new research suggests it was a series of eruptions or multiple vents spewing volcanic material in rapid succession. According to the U.S. Geological Survey’s (USGS) Yellowstone Volcano Observatory 2022 Annual Report (opens in new tab), published May 4, fieldwork over the past year has provided new geological evidence that “the formation of Yellowstone Caldera was much more complex than previously thought.” A caldera is a large crater that forms after the collapse of a volcano following an eruption. Yellowstone is one of the world’s biggest volcanic systems. It sits above one of Earth’s “hotspots” — areas in the mantle where hot plumes rise and form volcanoes on the crust above. It has produced three caldera-forming eruptions (opens in new tab) in the past 3 million years: the Huckleberry Ridge Tuff eruption, 2.1 million years ago; the Mesa Falls eruption, 1.3…