The next time a supervolcano eruption pours enough ash into the atmosphere to alter the Earth’s climate, humanity may not see it coming. That’s because volcanoes large enough to cause such a dramatic shift in sunlight, often termed “supervolcanoes,” may offer no warning that they are preparing to erupt. Geologists had previously identified specific warning signs that they believed preceded such massive eruptions, but this latest research seems to indicate that these telltale signs are not necessarily present before each and every climate-altering eruption.
BACKGROUND: SUPER VOLCANOES AND WARNINGS
In the movies, these types of massive volcanic eruptions are often preceded by a series of tragic events. These calamities may include mini-earthquakes, localized lighting storms, or even birds falling from the sky. In real life, geologists who study previous explosions of this magnitude look at changes in the environment as well as the volcano itself to try to understand the warning signs such climate-altering eruptions may offer. Such cues may include deforestation, altered landscape from rising magma, and chemical changes to the soil.
The Debrief covered the risk of such an explosion back in September, involving the same Indonesian supervolcano highlighted by the latest research.
ANALYSIS: SUPERVOLCANO ERUPTION WARNING SIGNS NOT ALWAYS PRESENT
In this study, researchers from Peking University checked to see if magma was accumulating at a rapid enough rate beneath the volcano to cause an eruption. In some ancient cases the answer was yes, but as they moved forward in time, they saw that the rate between explosions was decreasing without the signs of an increased magma accumulation.
“This is a ‘vicious circle’ of eruptions,” said Peking University geologist Ping-Ping Liu in a story from ScienceAlert. “The more the magma heats the crust, the slower the magma cools and the faster the rate of magma accumulation becomes.”
The group’s research, which was published in the Proceedings of the National Academy of Sciences, also reported that telltale signs in the localized environment were not present before every massive eruption, noting that “our results indicate that significant variations of monitoring parameters, such as increased surface deformation or degassing, may not occur before supereruptions.”
OUTLOOK: DOOMSDAY MAY BE COMING AND WE MAY NOT KNOW WHEN
In the ScienceAlert piece, the team notes that there are currently thought to be 5-10 volcanoes worldwide that might pack enough punch to blanket much of the atmosphere in ash, including the Lake Toba volcano in Indonesia that was the center of the study. And, they also note, if the past is any guide, such an explosion could not only alter the earth’s climate for as much as a decade or more, but may simply arrive without warning.
“Our study also shows that no extreme events occur before a super-eruption,” said earth scientist Luca Caricchi from the University of Geneva in Switzerland, in the ScienceAlert piece. “This suggests that signs of an impending super-eruption, such as a significant increase in earthquakes or rapid ground uplift, might not be as obvious as pictured in disaster movies by the film industry.”
Follow and connect with author Christopher Plain on Twitter: @plain_fiction