A volcano will become active and erupt in the U.S. again.

Atotal of 510 earthquakes occurred in a single region of Yellowstone National Park in September—a number that is around double the average.

The quakes took place near Grizzly Lake in the northwest region of the park, between the areas of Norris and Mammoth, as part of an earthquake “swarm” there that started in July, according to the United States Geological Survey (USGS).

Since then, there have been roughly 800 earthquakes altogether.

All of the earthquakes in September were small. Across the whole park, the largest was a magnitude 3.9 quake. An earthquake of this magnitude might be felt by a person but would rarely cause anything more than minor damage to structures or objects.

The Cumbre Vieja volcano spews lava and smoke as it continues to erupt on the Canary Island of La Palma, as seen from El Paso, Spain, October 11, 2021. (photo credit: SERGIO PEREZ/REUTERS)

Underneath Yellowstone National Park, a lava-filled river flows. This river is likely to erupt – but when, and what can spectators do to prepare for a disaster of the sort?

The Yellowstone caldera’s magma reservoir contains partially melted earth’s crust. The extent of the melt was far more than scientists were expecting to see. This extensive melt had been enough to convince scientists that they were dealing with a conductor – magma in such a volume that it could incite other eruptions to come.