GUERNSEY – People in the Guernsey area may have felt the Earth move under their feet Saturday morning from the effects of a reported magnitude 2.5 earthquake.

Seth Wittke, division manager for Hazards, Mapping and Water Resources with the Wyoming State Geological Survey in Laramie, confirmed the occurrence on Monday. According to U.S. Geological Survey data reports, the earthquake was centered about 5 kilometers below the surface and somewhere south of Guernsey at about 7:20 a.m. Saturday morning.

USGS reported the epicenter of the earthquake was 3.3 kilometers, or just more than two miles, south of Guernsey. However, the reporting model has a plus- or minus- variation of 3.6 kilometers.

“We’re showing 14 responses from the Guernsey zip code” to the trembler, Wittke said. “An one report from Hartville. There were no reports of responses or it being felt in the Wheatland area.”

There were no reports of injury or damage, he said.

A magnitude 2.5 earthquake falls into the least-active range of earthquakes, ranging from magnitude 1 to 3, according to the USGS website. Earthquakes of that magnitude may only be felt by a handful under “especially favorable conditions,” the website states. 

“A typical rule of thumb I use is, in areas within a fairly close distance to the epicenter, you can feel an earthquake down to a magnitude of 2.5,” Wittke said.

While the exact cause of the quake is not known, he said it was probably a naturally-occurring phenomenon, attributable to the normal subsurface shifting. But it was definitely an unusual event for the area, not known for its earthquake activity.

“This is more unusual than, say, the western part of the state,” Wittke said. “There’s no known tectonic activity in the area. But that doesn’t mean earthquakes haven’t happened in that area before.”