Yellowstone’s supervolcano gets all the attention these days, but it’s not the only vessel of apocalyptic eruptions. Today, there are several spots around the world that could bring about a game-changing eruption, and volcanologists are always on the hunt for ancient ones that until now have slipped beneath the radar.
Now it seems that they’ve confirmed another, and it’s been hiding in the Pacific Northwest. Writing in the journal Geology, the team – led by Washington State University (WSU) – explained that although the eruption has been known about for some time, geochemical analysis of its remnants reveals just how spectacular it was.
It began erupting 16.5 million years ago, and didn’t stop for tens of thousands of years; in doing so, it deposited up to 276 billion tonnes (305 billion US tons) of sulfur dioxide into the atmosphere, which turned into an unfathomably widespread acid rainstorm.
Sulfuric acid also happens to be a compound that’s a potent deflector of sunlight. When Mount Tambora erupted in 1815, for example, it released so much of the stuff that the Northern Hemisphere lacked a distinctive summer the following year.
That’s nothing compared to the Columbia River Flood Basalts (CRFB), whose sulfur output was 4,000 times that of Tambora. This is the equivalent of one Tambora paroxysm “every day for 11 to 16 years,” according to the researchers.
At the time, the planet was going through a warming spike known as the Miocene Climatic Optimum. However, this eruption coincided with a significant dip in global temperatures during its heyday, suggesting that its sulfuric belch was enough to quickly chill the planet.
Study co-author John Wolff, a professor of environmental science at WSU, said in a statement that a similar eruption today “would devastate modern society globally.”