It could also set off Yellowstone Supervolcano:

Yellowstone's Supervolcano Gets a Lid


In other words, the team needs to find an additional heat source. Leonard thinks this could come from the Juan de Fuca Ridge—a jagged volcanic seam where magma oozes up between spreading plates to create a new seafloor—in the Pacific Ocean. Although that’s almost 1,600 kilometers away from Yellowstone’s hotspot today, the ridge can easily affect the middle of the North American Plate. Because it lies just slightly west of the Cascadia subduction zone, the young seafloor is easily shoveled east beneath the North American Plate. So it is likely that some event, millions of years ago, spurred a lot of heat within the Juan de Fuca Plate, which was then shoveled underneath the North American Plate and swept along with that string of volcanic eruptions until it eventually helped form Yellowstone’s gaping caldera in the Rocky Mountains.

Although scientists will continue to argue over Yellowstone’s murky origin, the model makes it clear that slabs are much more important than previously thought. “It's like smoke from a chimney that's getting swept up in some sort of windstorm,” Humphreys says. “But it's not this vigorous plume that just blasts through everything.”

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