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Expert: Quakes likely had common epicenter
By Karl Henkel
YOUNGSTOWN
A seismologist says all 12 Mahoning Valley earthquakes likely had the same epicenter, contrary to original seismic data.
Won-Young Kim, a seismologist for the Lamont- Doherty Cooperative Seismic Network, said Tuesday that it is likely all earthquakes centered near a brine-injection well in Youngstown had similar epicenters, much closer to the well, a fact unknown until the 10th and 11th earthquakes Dec. 24 and Dec. 31.
“That is probably the case,” Kim said. “The location is much tighter. We know within a few hundred meters.”
Kim said there was not enough seismic data to determine precise epicenters of the first nine earthquakes because there was only one seismograph in the region — at Youngstown State University — but that 20 to 30 regional seismographs somewhat accurately pinpointed locations.
Original seismic data pinpointed epicenters within a 3-mile radius.
The Ohio Department of Natural Resources in December sought out Lamont-Doherty, at Columbia University in New York, to install four additional portable seismographs.
Lamont-Doherty installed the technology to determine with accuracy an earthquake’s depth; seismologists say multiple stations are needed to pinpoint precise depths. The Dec. 31 quake had a depth of about 2 miles, much shallower than previously recorded quakes.
Beginning last March, 12 earthquakes of small but varying magnitudes struck near a brine-injection well owned by Youngstown-based D&L Energy Inc.
The 11th, on New Year’s Eve, registered as a magnitude-4.0, the strongest of the dozen quakes.
The D&L well and five others remain shuttered pending the results of ODNR research, expected to be released later this week.
D&L on Tuesday referenced a third party that will “conduct extensive geological and seismic studies” near the well.
“This study will be comprehensive and utilize the best science available,” spokesman Vince Bevacqua said. “The resulting data will be much more extensive than the limited information currently available. It is hoped the new data will address issues of true seismic causation, not just location.”