According to a recent study published in Nature Geoscience, the Yellowstone super-volcano could be ignited by a distant heat source off the Pacific Northwest coast. This latest finding actually challenges the hypothesis which believed that the mantle plume beneath Yellowstone is responsible for volcanism at its surface.
"The heat needed to drive volcanism usually occurs in areas where tectonic plates meet and one slab of crust slides, or subducts, under another," Lijun Liu, lead author and geology professor at University of Illinois at Urbana-Champaign, said in a statement.
"However, Yellowstone and other volcanic areas of the inland western U.S. are far away from the active plate boundaries along the West Coast. In these inland cases, a deep-seated heat source known as a mantle plume is suspected of driving crustal melting and surface volcanism," Liu added.
The study, published in mid-December, will help the scientists to get a better understanding of the complex volcanic system that may erupt soon. However, the report did not point to any future super eruptions.
The scientists have used seismic tomography to determine the geologic history behind the Yellowstone volcanic system. They studied the possible geologic histories of the past 20 million years in the western US, but did not find much support for the mantle plume hypothesis. The findings of the team of researchers point to the Pacific Ocean's plates as the super-volcano's heat source.
Science News reported that a broken-off piece of the ancient Farallon plate has been slowly sliding east beneath the western part of the U.S. beginning about 200 million years ago and reached closer to the Yellowstone.
According to the researchers, the breaking of the ancient plate's fragments could have led to outpourings of magma and retained the heat in Yellowstone's volcanic system.
"A robust result from these models is that the heat source behind the extensive inland volcanism actually originated from the shallow oceanic mantle to the west of the Pacific Northwest coast," Liu said. "This directly challenges the traditional view that most of the heat came from the plume below Yellowstone."
Apart from this, the scientists also found out the hot materials like those in the mantle plume should rise towards the surface. However, they discovered that the mantle plume was sinking deeper into Earth.
Liu said that it "seems counterintuitive," but he believes that this specific finding led the researchers to point their attention towards the Pacific Ocean. Quan Zhou, co-author and graduate student, said that future studies will surely add chemical data from volcanic rocks to the model.
"That will help us further constrain the source of the magma because rocks from deep mantle plumes and near-surface tectonic plates could have different chemistries," Zhou said in a statement.