Beneath the Yellowstone National Park lies a giant reservoir of magma, so enormous that it can fill up the Grand Canyon 11 times.
Seismologists at the University of Utah used seismic tomography to create 3D images of the hot, partly molten rock lying 12 to 28 miles beneath the Yellowstone National Park. The team also combined seismic information of nearby areas and distant areas to map out the chambers -- the nearby quakes determine the upper magma chamber, while the distant quakes determine the lower chamber.
"For the first time, we have imaged the continuous volcanic plumbing system under Yellowstone," Hsin-Hua Huang, study lead author and postdoctoral researcher in geology and geophysics, said in a news release. "That includes the upper crustal magma chamber we have seen previously plus a lower crustal magma reservoir that has never been imaged before and that connects the upper chamber to the Yellowstone hotspot plume below."
The findings showed that the upper magma chamber of the Yellowstone supervolcano is nine percent molten while the lower magma reservoir is two percent molten, contradicting an early belief that both were composed of 100 percent molten rock.
Supervolcanoes are capable of causing maximum destruction when they erupt. The Yellowstone supervolcano's last eruption occurred 640,000 years ago, and researchers are not seeing that happening again anytime soon.
"The existence of the second magma chamber does not make it any more or less likely that a large volcanic eruption at Yellowstone will occur. These findings do not change the current volcanic hazard at Yellowstone," Jamie Farrell, study co-author and seismologist at the University of Utah, told Reuters.
"However, these new findings do provide us, and other researchers, the information needed to gain a better understanding of how magma moves from the mantle to the surface," he added.
Understanding how the supervolcano plumbing system works is critical in the development of models that experts can use to predict the impact of its eruption, as well as draft precautionary and contingency measures.
The study was published in the April 23 issue of Science.
