It would be a completely devastating scenario that would cover the entire United States.
The Yellowstone supervolcano is one of the most volatile places on Earth. With its 72 km distance and one of the largest magma calderas on the planet, this supervolcano represents one of the greatest risks in America. An eruption of the Yellowstone supervolcano would mean a real geological change for a large part of the planet.
What would happen if the Yellowstone supervolcano erupted?
Due to the magnitude of the geological formation represented by the Yellowstone caldera, the National Park would become a toxic zone, and virtually the entire United States could be covered with volcanic ash. The vegetation and fauna living there would die completely, while the pyroclastic flows of the supervolcano would affect nearby states.
A completely devastating scenario would cover the entire United States; however, despite the latent presence of small seismic swarms, an eruption at the Yellowstone supervolcano is currently unlikely because the earthquakes do not exceed 3° in magnitude.
More magma, more force...
Recently, an international team of researchers led by geologist Ross Maguire of the University of Illinois Urbana-Champaign conducted a study to determine how much magma is beneath Yellowstone and how it is distributed. Magma is the melt in its liquid form that is used to predict eruptions by comparing current conditions with those that predicted past eruptions.
In the study, the researchers used a new topographic imaging technique to analyze seismic wave recordings taken between 2000 and 2008 and applied a process known as full waveform inversion to better interpret the bouncing and reflecting vibrations.
Based on changes in wave velocity measured at different depths, the researchers were able to estimate that the soft magma reservoir beneath Yellowstone has a partial melt fraction of between 16% and 20%, compared to previous models that estimated less than 10%.
According to landscape estimates, 35-50% melt is needed to trigger an eruption, although there are several factors at play that make these phenomena difficult to predict. They claim that even the most modern exploration methods can miss certain pockets of liquid magma.
“Although our results indicate that the Yellowstone magma reservoir contains a considerable amount of melt at depths that fueled previous eruptions, our study does not confirm the presence of an eruptive body nor does it imply a future eruption,” Maguire wrote in the published paper.
Predictive models are constantly being refined as new data are obtained and new eruptions occur. Three catastrophic eruptions have occurred at Yellowstone in the past 2.1 million years, and while it is unknown when the next one might occur, a clearer indication of the caldera’s geology is helpful.
“Deformation events, such as new magma intrusions or tectonic deformations that could begin to mobilize and concentrate magma, would likely be accompanied by a series of dynamic processes for ongoing geophysical and geochemical monitoring,” the researchers said in the paper.
The area is under constant observation by the U.S. Geological Survey and the Yellowstone Volcano Observatory, which will allow early warning signals to be picked up.
Story originally published in Spanish in Ecoosfera