A Magnitude 4.0 earthquake was reported this afternoon at 20:04:58 UTC in northeastern Ohio. This is in the same area as a sequence of earthquakes thought to be associated with injection wells used to dispose of oil drilling waste fluids. The injection wells operations were suspended yesterday by the state of Ohio and the operator of the well.
Even though my seismograph in Millersburg, OH is not well suited to picking up local earthquakes and the display has been quite noisy the last few days, with a small amount of processing I did pick up a signal that appears to be caused by the earthquake in question.
The USGS arrival time information is shown:
DATE-(UTC)-TIME LAT LON DEPTH MAG Q COMMENTS 2011/12/31 20:04:58 41.16N 80.73W 2.2 4.0 us: YOUNGSTOWN-WARREN AREA, delta azimuth (degrees clockwise from north) (deg) eq-to-station station-to-eq 1.06 236.2 55.4 travel arrival time # code time(s) dy hr mn sec 1 Pg 20.39 0 20 5 18 2 sPg 20.92 0 20 5 18 3 Pb 21.09 0 20 5 19 4 pPb 21.44 0 20 5 19 5 sPb 21.83 0 20 5 19 6 Pn 21.88 0 20 5 19 7 pPn 22.41 0 20 5 20 8 sPn 22.74 0 20 5 20 9 Sg 35.19 0 20 5 33 10 Sb 36.46 0 20 5 34 11 sSb 37.05 0 20 5 35 12 Sn 38.13 0 20 5 36 13 sSn 39.00 0 20 5 37 14 PcP 510.96 0 20 13 28 15 ScP 722.84 0 20 17 0 16 PcS 723.12 0 20 17 1 17 ScS 935.02 0 20 20 33 18 PKiKP 994.23 0 20 21 32 19 pPKiKP 994.99 0 20 21 32 20 sPKiKP 995.27 0 20 21 33 21 SKiKP 1206.10 0 20 25 4 22 PKKPdf 1917.27 0 20 36 55 23 SKKPdf 2129.14 0 20 40 27 24 PKKSdf 2129.42 0 20 40 27 25 SKKSdf 2341.29 0 20 43 59 26 P'P'df 2428.55 0 20 45 26 27 S'S'df 3276.86 0 20 59 34
Postscript:
Several people have asked me about the triggering of earthquakes by hydraulic fracturing and waste injection wells. The USGS has a FAQ page on the subject.
Murmurs from the Earth... 
WKSU had a piece on the issue http://www.wksu.org/news/story/30342
Do you have an opinion on the subject? Or is it just the old correlation is not causation thang.
Dave
Yep, I heard the KSU piece this morning. My opinion is that the Lamont-Doherty Earth Observatory seismologist will give us the best data and analysis of what is going on there. I think WKSU is interviewing one those folks this evening.
That part of the state has some historic seismic activity, although not too much down by Youngstown from the maps I’ve seen. It sure seems like if you pumped lots of fluids under pressure down into old faults/fractures…you might open/lube one up enough to let it slip.
The NPR report on it just aired…John Armbruster of LDEO basicly came to the same conclusion.
I read the transcript – I thought he came off as pretty measured in his words. You’d never know it by reading the comments….. The blogospheric commentariat surely seems to bring out the wackaloons. (Mic’s blogs excluded, of course…)