Department of Earth and Environmental Sciences
People have been asking why Weston Observatory didn’t record the recent “seismic event” in North Korea.
It was much too small (magnitude 5.1) for us to see it this far away at our New England Seismic Network (or BC-ESP) stations. For us to see a seismic event at that distance, it would probably have to be about a magnitude 6.0 or higher. However, Weston Observatory seismologists also track recordings at seismic stations operated by collaborating observatories that are closer to North Korea.
Here are the seismograms at Weston, MA where it wasn’t recorded and at the IRIS/USGS station at Mudanjiang, China (MDJ) where it was recorded very well. This figure shows the MDJ seismogram and also the “spectrogram” (multi-colored plot, calculated by Dr. Jay Pulli, Visiting Scholar at Weston Observatory).