Previous seismological studies had indicated the presence of a substantial reservoir of magma beneath the Yellowstone caldera. However, a recent investigation employing the magnetotellurics method, which assesses the electrical conductivity of magma, yielded contrasting results.
Lead author Ninfa Bennington, a research geophysicist at the Hawaiian Volcano Observatory, shared insights from the study, stating, “When we used magnetotellurics, we were able to see, actually, there’s not a lot there.” The research revealed that instead of a singular large reservoir, there are distinct segregated regions where magma is stored throughout Yellowstone.
The study pinpointed the locations of the magnetotelluric stations with purple triangles, while highlighting subterranean chambers housing basalt magma in the orange region. This basalt magma, identified as the heat source for eruptions, was found to be linked to rhyolitic magma, which is closer to the surface, beneath the northeast portion of Yellowstone.
Bennington emphasized that the percentage of magma stored in the reservoirs was relatively low, indicating that none of these reservoirs are currently primed for eruption. The research projections suggest that the northeast section of Yellowstone is unlikely to experience another eruption for hundreds of thousands of years.
Further investigations enabled researchers to predict the location of the next eruption within the park. By leveraging magnetotelluric data, they identified the heat source fueling the active shallower magma reservoirs at Yellowstone to be situated in the park’s northeast quadrant.
Bennington highlighted that this crucial heat source, often referred to as the engine, is intricately linked to the primary magma storage zone within the park.
The Yellowstone Caldera, originating from the Lava Creek Tuff eruption over 600,000 years ago, is a testament to the geological history of the region. This cataclysmic event, rated an 8 on the Volcanic Explosivity Index by the U.S. Geological Survey – the maximum rating on the scale – solidified its status as a super eruption. In comparison, the 1980 eruption of Mt. St. Helens was categorized as a level 4 event.
Emanating from this super eruption, the Yellowstone Caldera sprawls across a vast expanse measuring 30 by 40 miles. The eruption, as per the National Park Service, blanketed an area nearly equivalent in size to Rhode Island. The repercussions of this monumental event extended over 1,000 miles, scattering ash and debris as far as Southern California and Louisiana.
In conclusion, the recent study sheds light on the complex magma dynamics beneath Yellowstone National Park, offering valuable insights into the dormant supervolcano’s potential for future eruptions.
