Small earthquake shakes part of Chester County

WEST CHESTER, Pa. (WPVI) -- Part of Chester County felt the ground shake over the weekend. A small earthquake hit and people have been wondering how it could have happened.

"Just felt like a stampede of elephants."

Today at Downingtown Diner, Tyler Faust explained he was at Regal Cinemas Sunday evening off Quarry Road when he felt shaking.

It only lasted about five seconds.

Faust says, "Everybody just got up in the middle of the movie, went out, and was just like what's going on?"

The US Geological Survey reported a 2.7 magnitude quake at 6:25 Sunday evening. There were no reports of injuries or damage.

In fact, Clara Dandrea didn't feel it. She learned about it later on social media.

She says, "I went onto Twitter - everyone was like, 'Oh my gosh. Earthquake.'"

At West Chester University, they installed a state of the art seismometer last summer, and of course it picked up Sunday night's activity.

Dr. Hal Bosbyshell of West Chester's Geology Department explains, "We're probably the closest station on this seismic network to record it, which is kind of neat."

Dr. Bosbyshell says their seismometer can pick up signals from earthquakes all over the world. The epicenter of Sunday's quake was in East Bradford Township, and would be considered small.

"The movement of the earth was about well under a millimeter - well under 100th of a millimeter," he said.

The epicenter was about a mile from a quarry. Workers there say there was no work going on at the time.

Dr. Bosbyshell says while the quarry is close in proximity, the quake could be completely unrelated and that there are natural explanations for it.

"The rocks around here are not tectonically active. But there are zones of weakness in the rock that were inherited from what was going on millions and millions of years ago," he said.

It might not have been large, you might not have felt it, but Dr. Bosbyshell says it was still interesting for students.

"The uniqueness is what makes it interesting, because it is so rare and unusual," Dr. Bodbyshell explained.