M5.0 – 25km NNE of Shawville, Canada

ontario_5_17may2013

There was a moderate, Magnitude 5.0, earthquake in southern Ontario, Canada this morning.  It registered as a small but nicely formed signal on my seismograph in northeastern Ohio, showing the P, S, and surface arrivals.  The orientation of my seismograph makes it less sensitive to earthquakes north and south of my location than it is to earthquakes east or west of us.  By my calculation this earthquake was about 456 miles northeast of my location.

USGS Event page is here: http://earthquake.usgs.gov/earthquakes/eventpage/usb000gxna#summary

Postscript: 

The USGS reduced the magnitude estimate to 4.4 after this post was written.