A swarm of earthquakes has shaken west-central Yellowstone National Park, according to University of Utah geologists.
The swarm, recorded late Monday about seven miles southwest of Madison Junction, was the latest in a year that has seen more earthquakes in the area than in any of the past 10 years, said Robert Smith, a University of Utah geophysics professor.But Smith said geologists are not sure what the increased quake activity means.
"You're asking the $64,000 question," he said. "We're keeping close tabs on this activity."
University of Utah monitors at about 10:05 p.m. Monday detected an earthquake with a magnitude of 4.2 about 10 miles south of West Yellowstone, Mont.
The earthquake was felt by several people at Old Faithful Geyser.
The main earthquake was followed by 20 aftershocks, one of which had a magnitude of 3.5.
There were no reports of damage or injuries resulting from the earthquakes.
The university' seismographic experts said earthquakes are not unusual in the area, which is near the northwest boundary of the Yellowstone caldera, a basin formed by volcanic activity.
However, they said activity in the caldera has increased since last summer.
"What the relationships are between earthquakes, Yellowstone's youthful volcanism and its geysers is the subject of the earthquake monitoring effort and ongoing research on what drives Yellowstone's active geology," the seismograph station's staff said in a statement released to news media.
Smith said the University of Utah has placed the monitors along the caldera to record activity in the park's volcanic network under a contract with the U.S. Geological Survey.
"Earthquakes are one of the key tools to predicting future eruptions," Smith said. "Yellowstone is a very young volcanic formation and very active."