Ancient Supervolcanoes Discovered in Utah Spread Magma, Ash Throughout West [VIDEO]

This article has been updated to note a change.

One of the largest volcanic eruptions in Earth's history spread ash from from central Nevada to Nebraska, casting a cloud throughout the modern-day Western United States.

Though silent today, the supervolcanoes blew open some 30 million years ago, spewing roughly 5,500 cubic kilometers of magma within a week in an explosion about 5,000 times larger than the 1980 eruption of Mount St. Helens.

In southern Utah where the supervolcanoes are located, in a place called Wah Wah Springs, deposits reach up to 13,000 feet thick, according to the study published in the journal Geosphere.

"Imagine the devastation - it would have been catastrophic to anything living within hundreds of miles," said lead researcher and Brigham Young University geology professor Eric Christiansen.

While dinosaurs may have been long gone at the time of the eruptions, the area would have been home to rhinos, camels and palm trees, the researchers said. 

The Wah Wah Springs eruption was not an isolated event, according to the researchers who uncovered evidence of 14 super-eruptions and 20 large calderas that, despite their massive size, long remained hidden from view.

"Supervolcanoes as we've seen are some of Earth's largest volcanic edifices, and yet they don't stand as high cones," Christiansen said. "At the heart of a supervolcano instead, is a large collapse."

The scientists used radiometric dating, X-ray fluorescence spectrometry and chemical analysis of the minerals in order to trace all the volcanic ash back to the same eruption.

"The ravages of erosion and later deformation have largely erased them from the landscape, but our careful work has revealed their details," Christiansen said.

Active supervolcanoes still exist today in places such as Yellowstone National Park in Wyoming where one roughly equivalent in size to the Wah Wah Springs caldera is located.