GoKawiilThe original version of this story appeared in Quanta Magazine.
In the summer of 1991, Pinatubo, a volcano in the Philippines, self-destructed. The eruption started on June 12, and three days later it culminated in a tremendous explosion. By the time pyroclastic flows—incandescent avalanches of molten rock and gas—tumbled down its sterilized slopes, Pinatubo’s peak had been obliterated and replaced by a 2.5-kilometer-wide chasm.
The eruption killed more than 800 people, mainly because roofs, weighed down by rain-saturated ash, collapsed. But it could have been so much worse: About 250,000 people, across multiple cities and a sprawling US Air Force base, lived in the volcano’s shadow. When Pinatubo started convulsing and belching steam in April of that year, scientists from the US and the Philippines deployed an array of instruments that tracked the volcano’s inner tumult.
“We didn’t know much about that volcano, and so there was this really rapid geological assessment. And the assessment said, ‘Oh, crap, when this thing erupts, it only erupts big,’” says Mike Poland, current scientist in charge at the US Geological Service’s Yellowstone Volcano Observatory. “And that became the basis for a forecast.”
By early June, ash and lava were escaping Pinatubo’s flanks, and an evacuation was ordered, just a few days before the cataclysmic hammer fell. It was, in other words, a very close call.
Those scientists saved countless lives, but their forecast was more of an educated guess than it might have appeared. It was nothing like a weather forecast; they couldn’t say with anything resembling certainty that on June 12 an explosive eruption was going to occur, nor could they predict the evolution of that eruption.
With very few exceptions, this imprecision is true of all well-monitored volcanoes. But volcanology, as a field, has made great leaps since Pinatubo blew its top. The instrumentation is more advanced, machine learning has made interpreting data far more efficient, and scientists have a much better understanding of the magmatic plumbing that drives volcanism. That’s prompted me—as a professionally trained volcanologist who now writes a lot about the field—to wonder: How close are we to forecasting volcano behavior the way we forecast the weather?
In this award-winning image, photographer Alberto Garcia captured a truck fleeing the cataclysmic eruption of Mount Pinatubo in the Philippines. Photograph: Courtesy of Quanta Magazine/Alberto Garcia
Today, we know that a storm of a certain magnitude will fall on a specific city in a few days’ time. Will scientists ever be able to say that a week from now, a certain volcano has an 80 percent chance of erupting in a particular way—with lava gushing, with a certain explosive force, with pyroclastic flows that will travel down its western flank? I asked around, and I found both skepticism and a surprising degree of optimism. “The short answer—otherwise I wouldn’t be doing this—is yes,” says Diana Roman, a volcanologist at Carnegie Science in Washington, DC.