Beneath America’s fourth most-visited national park, the apocalypse waits. There’s a supervolcano under Yellowstone, capable of shooting 1,000 cubic kilometers of rock and ash into the air. Enough to cover the entire planet. And now, scientists are learning that the entire process may happen faster than previously expected.
At IAVCEI 2017 in Portland, Oregon, researchers presented evidence that such eruptions only need a few decades of gestation before exploding. Considering how such eruptions are relatively rare, geologically speaking—there are only three known explosions in history, the last one occurring 631,000 years ago—there was an expectation that they needed a lot of preparation beforehand. That assumption is proving to be wrong, showing how much left there is to learn about supervolcanoes.
“If something like this happened today, it would be catastrophic,” says Hannah Shamloo, a geologist at Arizona State, speaking to the American Geophysical Union. “We want to understand what triggers these eruptions, so we can set up warning systems. That’s the big-picture goal.”
Alongside her Ph.D. adviser at Arizona State, geologist Christy Till, Shamloo examined two specific sorts of crystals known as phenocrysts, which form as magma cools a beneath a volcano. Varying between 1 and 2 millimeters each, these crystals are too large to have formed during the heat of an eruption. Rather, each crystal starts with a core that grows layer upon layer, forming a rough equivalent to the rings of a tree.
The outer rims of these phenocrysts show a clear change in temperature and composition occurring over a few decades, a geologic snap of the finger. “We expected that there might be processes happening over thousands of years preceding the eruption,” Till tells the New York Times. “It’s shocking how little time is required to take a volcanic system from being quiet and sitting there to the edge of an eruption,” Shamloo says.
However, there’s still a lot of work to be done before Shamloo’s dream of a warning system gets put into place. Scientists still need to figure out how these massive buildups transform into supereruptions. Because if one happens, you’ll need to run pretty fast if you want to escape it.
Source: New York Times
