Just after midnight on Sept. 8, all was quiet in the woods of Millport Conservancy, an 85-acre nature preserve seven miles northeast of the Franklin & Marshall campus. But more than 2,000 miles away, at the boundary of two tectonic plates in the eastern Pacific Ocean, the first seismic waves of Mexico’s worst earthquake in decades began propagating toward the state of Chiapas.
Over the next few minutes, the ground shook violently in southern Mexico as the waves of the magnitude 8.2 earthquake moved north. Soon the waves reached the southern border of the United States—though they were not noticeable by people at that distance from the epicenter—and eventually the mid-Atlantic states. That’s when Franklin & Marshall’s seismic station, at its new home atop a cliff overlooking a stream at Millport, came to life.
The seismic station recorded the bedrock shaking at Millport, marking its first big event after having been installed in late August by faculty, staff and students in F&M’s Department of Earth & Environment. The station is capable of detecting seismic waves generated by large earthquakes anywhere in the world. It also records small, local earthquakes; non-seismic events, such as quarry blasts in the Lancaster area; and microseisms (small, recurring tremors) from the impact of high-energy waves on the continental shelf.
Prior to the installation, the station was located on the west side of the Hackman Physical Sciences Building at F&M. It is part of the Lamont-Doherty Cooperative Seismograph Network, which operates 40 seismographic stations in seven states. When F&M’s station required repairs last year, the network asked the College if it could find a new location to get better data from an area north of Lancaster. The College’s long partnership with Millport Conservancy led to an ideal location.
View readings from F&M’s seismic station at go.fandm.edu/seismic-station.