A new study from the U.S. Geological Survey has shown that rhyolitic volcanism in the Yellowstone Caldera, often referred to as the Yellowstone Supervolcano, has shifted northeast.
According to the study, posted in Nature, rhyolitic melts are the source of caldera-forming eruptions, with three major ones occurring in the Yellowstone Caldera in the past two million years. This area is among the largest volcanic systems on Earth, with periods of smaller, less-explosive eruptions interspersed between the three major ones.
The rhyolitic melts are stored within the mid to upper crus, and seismic tomography studies have pointed towards a broad region of rhyolitic melt extending beneath the Yellowstone Caldera. The estimated melt volume is one to four times greater than the eruption volume of the largest past caldera-forming eruptions.
Magnetotelluric data are primarily sensitive to the presence of melt, making them ideal for constraining volcanic systems. For the study, researches utilized magnetotelluric data to model the Yellowstone Caldera’s crustal magma reservoir’s resistivity structure, allowing them to constrain the area’s potential for producing major volcanic eruptions.
Their research found that rhyolitic melts are stored in segregated regions beneath the caldera. That, in combination with their low melt fractions, indicate that the reservoirs are not eruptible. Based on their studies, rhyolitic volcanism in the Yellowstone Caldera is shifting northeast.