The September 25, 1998 Pymatuning Earthquake

A moderate size earthquake was epicentered near Jamestown, Pennsylvania at about 3:50 PM (eastern time) on Friday, September 25, 1998. This earthquake is commonly called the "Pymatuning Earthquake" because the epicenter was located near the southern end of the Pymatuning Reservoir.

This earthquake was felt over approximately 125,000 square miles of the northern United States and southern Canada. Reports of shaking came from as far east as New Jersey and Washington, D.C., as far west as Illinois and Wisconsin, as far north as Ontario, Canada and as far south as Virginia and Kentucky.

This earthquake had an estimated magnitude of 5.2, the largest in the recorded history of Pennsylvania. It was detected at seismograph stations throughout the United States and as far away as Mongolia. The seismogram here was recorded at a US Geological Survey seismograph station located at the West Virginia Geological and Economic Survey in Morgantown, WV.

One person was injured, many buildings were damaged and objects in homes and stores were tossed about. The most costly damage done by the earthquake was to water wells. About 120 wells went dry within three months of the earthquake. It is believed that this was caused by permeability increases in deep rock units that resulted in drainage of shallow aquifers.

This photograph was taken by taken by Pennsylvania Geological Survey staff at a grocery store near Jamestown, Pennsylvania. It shows minor damage of items thrown from grocery store shelves. This store is located about four miles from the estimated epicenter.

The USGS Earthquake Hazard Program's brief description of the earthquake reads: "Minor damage in the Greenville-Jamestown, Pennsylvania area. Felt throughout northern Ohio and most of Pennsylvania. Felt in northern Indiana, southeastern Michigan, New York as far east as Syracuse and West Virginia. Felt in parts of Illinois and New Jersey. Also felt in much of southern Ontario, Canada.