The USGS reported a Magnitude 3.0 earthquake in north central Ohio at 15:35:20 2011 June 05. The location was roughly 33 miles north of Millersburg. The raw helicorder display from my seismograph yesterday is shown with the cursor pointing to the time that the earthquake occurred near the center of the display. It doesn’t really show a signal. Something is there but it is very difficult to differentiate it from other portions of the display. There is a real earthquake signal two hours later from a Magnitude 5.8 tremblor in Fiji. The Fiji earthquake occurred almost exactly one hour after the Ohio earthquake but the surface waves took nearly another hour to get to Millersburg.
I am a little surprised that I didn’t pick up more of a signal from the Ohio earthquake simply because it was so nearby. It was north of my location and my seismograph is most sensitive to east-west motion. My seismograph is also tuned to respond to lower frequency signals associated with teleseismic events. Local events generally have higher frequency content.
Other things of note in the display are the large spikes in the upper left corner of the display due to power fluctuations as a heavy thunderstorm passed through the area. There is also a blank area caused by power outage of several hours. Other noises in the display are from foot traffic in the house and some undiagnosed signal occurring roughly every hour.