Researchers have discovered a previously unknown reservoir of magma under the Yellowstone supervolcano. They have added that this volcano, named the Yellowstone Caldera, contains enough magma to fill the Grand Canyon nearly 14 times over.
Hsin-Hua Huang, a postdoctoral researcher in geology and geophysics at the University of Utah, and the lead author of the study, said, “For the first time, we have imaged the continuous volcanic plumbing system under Yellowstone. 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.”
According to the researchers, the reservoir contains 11,000 cubic miles of magma. It is about 28 miles deep and more than four times the size of the long-known, shallower magma chamber that produced the ancient eruption and still powers the region’s geysers, steam vents and hot springs.
The researchers have added that that the Yellowstone Caldera has had three major eruptions in the past, and the last one occurred 640,000 years ago. However, the supervolcano is not about to erupt and annihilate all life on Earth. The overwhelming bulk of the magma reservoir, which extends 30 miles beneath the surface, is filled with mostly solid, ‘spongelike’ rock. The researchers added that while the upper magma chamber contains about 9% molten rock, the lower reservoir has only 2% of it.
The researchers believe that the new findings provides a better understanding of how hot and partly molten rock rises from a hotspot plume 40 miles beneath the Earth’s surface up to the magma reservoirs underlying the supervolcano.
For their analysis, the researchers combined seismographic data from the university’s seismographic stations throughout the region and from the EarthScope array of seismometers, which was funded by the National Science Foundation. The foundation has been mapping the underground structures of all 48 of the lower U.S. states.