It’s no secret that Yellowstone National Park sits atop a “ supervolcano .” But now, accounts of animals supposedly fleeing the park before an earthquake last Sunday have sparked fear that one of the world’s biggest supervolcanoes is about to produce an apocalyptic eruption.

In his “Rumor Control” video , Nash explains the natural geological system of the park, which has between 1,000 and 3,000 earthquakes a year. “Frankly, we are just a few miles above some really hot magma,” he says. That magma serves as the heat that fuels the geysers, hot springs, and fumaroles in the park -- you know, the iconic things that attract three million visits a year

This past Sunday, a magnitude 4.8 event -- later updated to 4.7 -- occurred at 6:34 am local time about four miles north of Norris Geyser Basin in Wyoming, according to the U.S. Geological Survey . It was most likely a strike-slip motion and may not even be linked to any volcanic processes. To be fair, it was the biggest earthquake in Yellowstone since the early 1980, though there are no reports of injuries or damage.

But that’s not to say a cataclysmic eruption can’t happen. The Yellowstone region has produce three exceedingly large volcanic eruptions in the past 2.1 million years. Enormous volumes of magma erupted at the surface and into the atmosphere as mixtures of pumice, volcanic ash, and gas spread as pyroclastic flows in all directions, a USGS report describes . The ground collapsed, creating the broad, cauldron-shaped volcanic depressions called calderas. The last time this happened was 640,000 years ago, and since then, about 80 (far less devastating) eruptions of lava have occurred.