Earthquakes in Pa. aren't new, but recent Mifflintown shake has 'unusual' qualities

York Daily Record

As the "did you feel that" question invaded social media Wednesday night, one thing seemed to be true — another earthquake shook central Pennsylvania.

The USGS confirmed that a 3.4-magnitude earthquake occurred about 11 miles southwest of Mifflintown in Juniata County.

Earthquakes aren't foreign to Pennsylvania, but retired Millersville University earth sciences professor Dr. Charles Scharnberger says there are a few unusual qualities with this one.

For starters, the epicenter of the earthquake in Juniata County is odd and new. Scharnberger said, to his knowledge, there has never been an earthquake in that area before, nor are there any fault lines.

An intensity map for an earthquake that struck near Mifflintown, Pennsylvania, on June 12, 2019.

Also, the depth of this earthquake was relatively deep. The USGS reported a 26.7-kilometer depth, which equates to a little over 16 miles below the earth.

"We do have earthquakes of this magnitude every few years in Pennsylvania," Scharnberger said. "The seismological community still does not understand why we have earthquakes on this coast."

Wednesday's earthquake occurred about 8:30 p.m. People all around the region - including Camp Hill, Mechanicsburg, Lititz, Harrisburg, Carlisle and York - reported that they felt it. According to the USGS, a 3.4-magnitude earthquake will be "felt only by a few persons at rest, especially on upper floors of buildings."

"Many people do not recognize it as an earthquake. Standing motor cars may rock slightly. Vibrations similar to the passing of a truck," the USGS states.

No damage was reported from the earthquake.

PAST EARTHQUAKE COVERAGE: