760,000 years ago, an enormous explosion ripped through California, and created a cauldron-like pit (caldera) that measured 32 by 18 kilometers (20 by 11 miles) across. The supervolcanic blast was so violent that the entire magma chamber was emptied and a vast section of the land collapsed in on itself, and almost the entire western US was buried in ash.
Although powerful, it pales in comparison to other eruptions. Toba’s last supereruption, for example, would have wiped out an area equivalent to 25 New York Cities. This research, therefore, may in the long-term prove to be a game-changer for volcanological prediction - but again, it's just a single study, so we can't make sweeping conclusions.
The business of determining when a volcano will erupt is less tricky than the equivalent for dangerous earthquakes, but it’s still no easy task. Certain warning signs – like ground deformation, sulfurous gas release, and precursor earthquakes – do provide volcanologists with perhaps a few days warning, but in many other cases, the eruption occurs with little to no warning at all, and many lives are often lost.
If this research is validated, then – providing we can recognize the surface-level signs of its impending explosion – societies may be able to provide their citizens with a considerable amount of time to evacuate the region. Yellowstone and Campi Flegrei, two other dormant calderas, currently sleep beneath highly populated villages, towns, and cities.
Ultimately, if properly applied, this is the sort of research that can save millions of lives.
Mammoth Lake rests just above Long Valley Caldera. Galyna Andrushko/Shutterstock