See map of earthquakes around region

The New Jersey earthquake Friday morning was just the latest of many to be felt in Pennsylvania over the years.

While it was one of the strongest quakes on record for the region, many others go unnoticed. The earliest records of earthquakes in Pennsylvania date back to colonial times.

Within Pennsylvania sits the Reading-Lancaster seismic zone, which is responsible for many of those tremors.

The map below shows the location of past earthquakes reported around Pennsylvania and neighboring states. Click on a marker for more details, including the magnitude, of each quake.

Source: U.S. Geological Survey

How common are earthquakes in eastern PA and why was the New Jersey earthquake felt so far away?