What happens when Yellowstone Supervolcano erupts? USGS revisits possibility, links it to climate change

  • The U.S. Geological Survey says a massive eruption from the Yellowstone Supervolcano would affect the entire world

  • In 1991, eruption of Mount Pinatubo in the Philippines cooled the global temperature for over 2 years

The U.S. Geological Survey (USGS) described what would happen once the Yellowstone Supervolcano erupts. As explained by the agency, the supervolcano's eruption will be so massive that it would most likely affect the entire global climate.

Historical and geological reports have shown that Yellowstone's eruptions millions and thousands of years ago were powerful enough to change the features of the regions around it. Because of this, many scientists believe that a future eruption would also have the same effects.


Yellowstone's Destructive Eruption

According to the USGS, the areas surrounding Yellowstone would experience one of the most destructive effects of its eruption. As noted by the agency, the states around the volcano would be affected by pyroclastic flows, which are characterized by the high-speed movement of lava mixed with ash and volcanic gas. Other areas in the country, on the other hand, would be covered in ash fall. The intensity of the falling ash would vary depending on the state's distance from Yellowstone.

"Those parts of the surrounding states of Montana, Idaho, and Wyoming that are closest to Yellowstone would be affected by pyroclastic flows, while other places in the United States would be impacted by falling ash (the amount of ash would decrease with distance from the eruption site)," the USGS stated.


Triggering A Volcanic Winter

Aside from the US, the USGS noted that the effects of Yellowstone's massive eruption could also affect the entire world. As explained by the agency, a major eruption could alter global temperatures. This will happen if the supervolcano emits enough volcanic ash and other debris into the atmosphere to prevent sunlight from entering.

Taking cues from the Toba Catastrophe theory, USGS said during such an event, known as a volcanic winter, global temperatures can decrease. The last time this happened was in 1991, when the eruption of Mount Pinatubo in the Philippines cooled the temperature around the world for a span of 2 to 3 years.

"If another large, caldera-forming eruption were to occur at Yellowstone, its effects would be worldwide," the USGS explained. "Such a giant eruption would have regional effects such as falling ash and short-term (years to decades) changes to global climate."