A new research finds that we may not have enough time to prepare once the supervolcano in and around Yellowstone National Park erupts. What could happen if, or when, it does?
Decades, Not Centuries In Waiting
Until recently, researchers and geologists believed that the critical changes in temperature and composition that could spark a supervolcanic eruption at Yellowstone National Park would take centuries to complete. However, an analysis completed by researchers from Arizona State University reveals that the changes could take decades, not centuries, giving us much less time to prepare.
The analysis of the minerals in the fossilized ash from the volcano's most recent mega-eruption shows that should the supervolcano suddenly begin to show signs of impending eruption, we would not have much time to prepare for its potentially catastrophic effects.
What Could Happen In A Supervolcanic Eruption?
The term "supervolcano" is used to describe volcanic eruptions with a Volcano Explosivity Index of magnitude 8. This implies an eruption with 250 cubic miles (1,000 cubic kilometers) of magma. The Yellowstone Volcano has had at least three supervolcano eruptions 2.1 million years ago, 1.2 million years ago, and just 640,000 years ago. The most recent of which is responsible for creating Yellowstone's caldera.
What could happen in a supervolcano eruption? To put things into perspective, the three most recent supervolcano eruptions at Yellowstone are described as being 2,000, 600, and 7,000 times bigger than the Mount St. Helens's eruption in 1980, which, by itself, caused lahars, over 10,000 earthquakes, a total of 2.5 cubic kilometers of avalanche debris, and blew 520 million tons of ash across the United States, causing darkness in Spokane, Washington.
Researchers estimate that during the Yellowstone's previous mega-eruptions, the western half of the United States was likely covered in volcanic ash and that even those living farther away still experienced a few inches of volcanic debris. Further, such massive eruptions are said to likely have caused a significant temperature drop worldwide. Should the supervolcano erupt, it could cover the entire United States in thick ash and alter the Earth's weather, turning it into a volcanic winter.
When Could This Supervolcano Eruption Happen?
There's no telling when volcano eruptions could happen, but today, the Yellowstone is one of the world's best monitored volcanoes, and there is so far no evidence saying that the supervolcano is rearing for an eruption any time soon. According to the United States Geological Survey (USGS), such large eruptions only occur once every 600,000 to 800,000 years.
Since its last supervolcano eruption 640,000 years ago, Yellowstone has had about 80 nonexplosive eruptions, some of which are as powerful as the 1991 Mount Pinatubo eruption in the Philippines, the second-largest volcanic eruption of the century.