UNIVERSITY PARK, Pa. — Pennsylvania may not be famous for its earthquakes like some other states, but seismic events happen every week at quarries and other mining areas, as does the occasional earthquake. When a seismic event occurs in the commonwealth, the Pennsylvania State Seismic Network (PASEIS) is the first to know.
The network is a collaborative monitoring effort between Penn State, the Bureau of Geological Survey in the Department of Conservation and Natural Resources (DCNR), and the Pennsylvania Department of Environmental Protection (DEP). PASEIS uses data from 71 stations within and surrounding Pennsylvania for monitoring purposes.
“There’s a lot of controlled, DEP-regulated blasting from quarries and coal mines, so every week we detect and locate explosions from mining activity,” said Andrew Nyblade, head of the Department of Geosciences and co-director of Penn State’s Marcellus Center for Outreach and Research (MCOR), which supports PASEIS. “Other man-made and natural processes also occasionally produce earthquakes. Although most are small, we can detect and locate them in near real time.”
Earthquakes are most likely to occur in northwestern and southeastern Pennsylvania. The latest one, a magnitude 1.3 that could only be felt by seismometers, happened near Lancaster this past October. The state has not experienced a sizeable event since the magnitude 5.2 Pymatuning earthquake in September 1998.
Four stations must record a seismic event to locate it, said Kyle Homman, PASEIS seismic network manager and a doctoral candidate at Penn State. Homman maintains and operates 37 stations across the state and pulls data from 34 stations operated by other universities, companies or government entities. Stations consist of computers and seismometers that can detect and locate all magnitude 2 and stronger events as well as many smaller events.