Yellowstone rocks?

The ground is shaking in Yellowstone, apparently.

Yellowstone National Park was jostled by a host of small earthquakes for a third straight day Monday, and scientists watched closely to see whether the more than 250 tremors were a sign of something bigger to come.

Swarms of small earthquakes happen frequently in Yellowstone, but it’s very unusual for so many earthquakes to happen over several days, said Robert Smith, a professor of geophysics at the University of Utah.

“They’re certainly not normal,” Smith said. “We haven’t had earthquakes in this energy or extent in many years.”

In Yellowstone there is actually a large volcanic caldera – what amounts to a dormant volcano. (You can view the US Geological Survey’s information on it here.) There’s been discussions about the ramifications of that caldera suddenly going active and the term “supervolcano” was coined as a result. Definitely something to keep an eye on.