YELLOWSTONE NATIONAL PARK, Wyo. -- The U.S. Geological Survey says the magnitude-4.8 earthquake that shook northern Yellowstone National Park is the strongest there since 1980.
But the Sunday quake was still considered relatively light, and its location didn't raise concerns about the park's supervolcano, which experts say has the potential to erupt with a force about 2,000 times the size of Mount St. Helens and would have worldwide effects.
The University of Utah Seismograph Stations says the earthquake occurred at 6:34 a.m. about 6.4 kilometres north-northeast of the Norris Geyser Basin. It was felt in the Montana border towns of West Yellowstone and Gardiner.
There were no immediate reports of damage. The park has few visitors and staff this time of year.
Yellowstone sees frequent earthquakes. At least 25 have been recorded since Thursday.