JACKSON, Wyo. — According to this week’s Caldera Chronicles written by the Yellowstone Volcano Observatory (YVO) and Volcano Seismologist Ninfa L. Bennington, Ph.D., lightning and solar storms can be used to map magma beneath Yellowstone National Park (YNP) and tell scientists about the the potential for where and when future eruptions might occur.
In a recent study, U.S. Geological Survey (USGS) investigators collaborated with Oregon State University and the University of Wisconsin-Madison to use a tool called magnetotellurics to image where and how much magma is presently stored beneath the Yellowstone caldera. YVO writes that the Yellowstone caldera is one of the largest volcanic systems in the world, with the last eruption in the region — a lava flow — over 70,000 years ago.
YVO defines magnetotellurics as “a geophysical method that uses variations in the Earth’s naturally occurring electromagnetic field, typically caused by lightening [sic] and solar storms, as a signal for imaging the subsurface.” According to YVO, the technique identifies structures within the Earth that are good conductors of electricity, like magma.
“Magnetotellurics an ideal tool for mapping where magma is distributed beneath active volcanoes,” YVO writes. “The magma storage areas imaged by the magnetotelluric study are not completely molten, however, and instead consist of a mush of packed crystals interspersed with liquid rhyolitic magma. If those pockets of liquid magma are well connected and sufficient in volume, a volcanic eruption could occur.”
The magnetotelluric data collected across Yellowstone caldera in the summers of 2017 and 2021 show that the concentration of magma stored is too low to feed an eruption at the present time. These results from the magnetotelluric study are very similar to studies of the Yellowstone magmatic system using seismic data, YVO confirms, which also suggest an overall low proportion of liquid magma beneath the surface.
“The magma stored beneath the surface of YNP exists in a mostly solid state and is probably not capable of erupting,” YVO writes.
Read more about when Yellowstone could erupt next here.
