On Thursday afternoon, a Dover, DE, earthquake was widely felt on campus and along the Eastern US, from New York City to Washington D.C. The seismic waves it generated were also recorded by seismologists in the Geosciences Department using a seismometer located in the basement of Guyot Hall.  Seismic waves traveled approximately 90 miles and the first signals recorded, corresponding to P-waves (compressional waves), were detected starting 22 seconds after the earthquake. Roughly forty seconds after the earthquake S-waves (shear waves) and then surface waves arrived, causing the stronger signals detected by Guyot Hall’s seismometer.  Occupants stated that tremors were slight on the first floor, however, were definitely felt on the third floor of the building.

In this image, the red line corresponds to when the earthquake happened, the blue line to the first seismic waves arriving and the purple line to the arrival of shear waves. 

The seismometer, run by Professors Jessica Irving & Frederik Simons, is used for research, including by a Senior Thesis student and PEI interns, and for teaching in the Geosciences department. The photograph shows Anna van Brummen ’17 adjusting the instrument.

Retated article:

Minor earthquake tremors felt on Princeton campus
https://www.princeton.edu/news/2017/11/30/minor-earthquake-tremors-felt-princeton-campus