What sounds scarier, a swarm of earthquakes or a supervolcano? Yellowstone National Park, one of the most seismically active places in the U.S., has both. And in September, the park experienced 510 little quakes in the Grizzly Lake region, more than double its average.
It’s been a seismically active summer. The swarm really started in July, with about 800 total earthquakes since then. All were small, with the largest being 3.9. This isn’t big enough to be destructive, and you might not even feel it. But still. That’s a lot of earthquakes. What’s going on?
When volcanic fluids move along underground rock fractures, you get swarms of earthquakes. USGS research physicist Mike Poland, who is also the scientist in charge of the Yellowstone Volcano Observatory, said Grizzly Lake usually gets about 150 to 200 earthquakes per month. But sometimes this number ramps up.
“There have been plenty of months where we’ve seen 800 to 1000 quakes,” Poland said, as reported by Newsweek. “For example, in July 2021, there was a swarm of over 800 quakes beneath Yellowstone Lake over the course of 10 days.”
Okay, Poland makes this sound normal and not scary. But worriers do worry about the Yellowstone Caldera (the supervolcano) saying if it blows again, it could wipe out the world as we know it. According to the USGS website, a few sizable earthquakes in an area could possibly trigger a volcanic eruption. That is, if the volcano is already poised to erupt and all conditions are right. The supervolcano has had three super eruptions in the past: 2.1 million years ago, 1.3 million years ago and 664,000 years ago.
This is pretty infrequent, in the grand scheme of things. So while Yellowstone is geologically fascinating and nature lovers should definitely visit, the supervolcano is extremely unlikely to blow again soon, despite all these little quakes. There are many other global issues that are probably better uses for your time spent worrying about Earth’s demise, if you are so inclined.
Lead image via Pexels