Supervolcano Eruptions Will Follow Massive Seismic Activity, Study Shows

After the Yellowstone supervolcano’s last two massive eruptions around 630,000 years ago, gargantuan clouds of ash and smoke filled the sky, blotting out the sun and cooling the oceans by about 3 degrees Celcius. Even considering the dire need to keep global temperature rise below 2 degrees Celcius, that’s a frightening prospect. But according to a new study recently published in Geophysical Research Letters, we should have plenty of time to prepare for an impending volcanic winter.

In order to examine the effects of tectonic movement on supervolcano eruptions, researchers Haley E. Cabaniss, Patricia M. Gregg, and Eric B. Grosfils created a computer model of the Taupo supervolcano in New Zealand. Then, they adjusted the variables in the model, checking to see how the volcano would respond to different amounts of seismic stress with different levels of magma. Regardless of the tectonic activity, they found that supervolcanoes will likely remain stable for hundreds or thousands of years when their magma reservoirs are growing.

That is, when a volcano’s magma reservoir is being actively augmented, the timescale for an eruption shortens to hundreds or thousands of years. But volcanoes can lie dormant for far longer. Yellowstone’s most recent (less massive) eruption resulting in lava flow was around 70,000 years ago. When volcanoes are dormant, they aren’t being supplied with magma, so they remain indefinitely stable.

“When new magma starts to rejuvenate a supervolcano system, we can expect to see massive uplift, faulting and earthquake activity,” Gregg said in a statement. “Even then, our models predict that the system would inflate for hundreds to thousands of years before we witness catastrophic eruption.”

Gregg said that geological activity preceding an eruption could include tectonic uplift of tens to hundreds of meters. And these signs don’t suggest the volcano would even erupt that soon. Rather, they indicate that the supervolcano’s reservoir is being filled with magma, and it could erupt in hundreds or thousands of years — plenty of time to prepare for damage control.

“People need to keep in mind that sites like Yellowstone are very well-monitored,” Cabaniss added. “Our models indicate that there should be plenty of warning.”