California residents afraid that Yellowstone may erupt soon

After two giant earthquakes hit in California last week, there was a spike in internet searches for Yellowstone caldera and Yellowstone volcano. The quakes—a magnitude 6.4 and 7.1 on July 4 and 5 respectively—had apparently raised fears an eruption on the supervolcano could be triggered by these events. Associated search phrases, in response to Google Trends, included “California earthquake” and “the big one California.”

However these fears are completely unfounded, the USGS has stated. In an article on the Yellowstone Volcano Observatory website, scientist-in-charge Mike Poland has explained what influence earthquakes have on volcanic activity—and why the quakes in California won’t cause Yellowstone to erupt.

He said that strong earthquakes should not a rare occurrence for the western U.S. The region is covered in fault lines—an interactive map of them can be found here. Fault traces are cracks within the Earth’s crust which have the potential to trigger earthquakes once they move round.

“Since 1900, in the continental U.S. there have nearly 100 earthquakes greater than M6, and there have been nine better than M7 (each of these numbers go up if you happen to include Canada and Mexico),” Poland wrote. “Most of those events are in California, but they’ve additionally occurred in Oregon, Washington, Nevada, Utah, Idaho, Montana, and Wyoming. If we assume that rate is representative of the average, that means there could be about 10 M7+ events per century within the western USA.”

It has been over 70,000 years since Yellowstone last erupted. Over this time, there may have been over 7,000 strong earthquakes—none of which have led to an eruption at Yellowstone. Poland additionally mentioned that the distance of the earthquake to Yellowstone doesn’t matter—in 1959 a magnitude 7 earthquake hit on the Montana-Idaho border, on the boundary of the National Park, but there was nonetheless no eruption.