Drilling Down

More Earthquakes Detected in Lawrence County, Pa.

YOUNGSTOWN, Ohio – At least five small earthquakes were detected Monday near New Castle, Pa.,  over 22 hours,  the U.S. Geological Survey reports.

Survey data show that after  the 1.9-magnitude quake  recorded shortly after midnight April 25 in Mahoning Township , four more occurred. Roughly four hours after the first tremor, a second quake in the vicinity registered 1.7, and a third, a 1.8-magnitude quake, followed an hour later.

The fourth quake, which measured 1.9 on the Richter scale, was detected around 9 a.m. and a fifth registering 1.8 occurred shortly after 10 p.m.

Seismic monitors administered by Penn State University detected the quakes, as did other monitoring stations used by the Survey, said Andrew Nyblade, professor of geosciences at Penn State. The Pennsylvania Department of Environmental Protection and the Pennsylvania Department of Conservation and Natural Resources funded the Penn State monitors and are in the process of expanding the number of seismic detectors throughout the state by 30 to a total of 42.

“We’re filling in gaps where there isn’t coverage,” Nyblade said. The expanded network should be in place by the summer.

Earthquakes that register 2.5 and below on the Richter scale are rarely felt.

The epicenters of the quakes were clustered near a horizontal drilling and hydraulic fracturing operation in North Beaver Township at the North Beaver NC well pad just off state Route 551. Houston-based Hilcorp Energy Co. shut down operations there around noon Monday.

According to Pennsylvania DEP spokeswoman Melanie Williams, the company was in the process of hydraulically fracturing two horizontal wells that angled in a northwest direction. Two wells drilled at the site that went southeast were completed earlier this month.

The DEP is investigating whether a link exists  between the tremors and the hydraulic fracturing operation. The wells targeted the Utica/Point Pleasant shale formation.

As of yet,  no official link has been found to the quakes and the hydraulic fracturing operation in North Beaver Township.

Hilcorp has not returned calls for comment.

The well pad is also close to the Carbon Limestone Landfill across the Ohio state line in Poland Township in Mahoning County, where Hilcorp has drilled seven horizontal wells on two pads.

In March 2014, Hilcorp ceased a hydraulic fracturing operation there after a 3.0 earthquake was recorded near the well pad. A study subsequently determined that hydraulic fracturing likely triggered the tremors.

Penn State’s Nyblade said that it’s likely the geology in Poland Township is similar to where the new drilling occurred in western Pennsylvania. “There’s at least one paper that’s been published that argues fracking caused the Poland Township quakes, and it’s only a few miles away. I’d say The geological situation is the same,” he said.

In 2011, a wastewater injection well in Youngstown triggered a 4.0 magnitude earthquake on New Year’s Eve 2011. That operation too was closed down.

Published by The Business Journal, Youngstown, Ohio.