31st Dec 2011
“It was like someone pushed it down,” the 79-year-old woman said.
It had been standing by the fireplace in her living room until an earthquake tied to injection wells near Youngstown rumbled across Northeast Ohio.
The 4.0-magnitude quake was centered near Youngstown, reported the U.S. Geological Survey and the Ohio Earthquake Information Center.
The earthquake at 3:05 p.m. was felt as far away as Michigan, Ontario, Pennsylvania and New York, reported Michael C. Hansen, state geologist and coordinator of the Ohio Seismic Network, part of the Ohio Department of Natural Resources’ Division of Geological Survey.
The quake was “a pretty good-sized one,” he said.
There were no initial reports of injuries or major damage, he said.
The quake was the 11th over the last eight months in Mahoning County, all within two miles of the injection wells, he said. Saturday’s quake was the largest yet.
A quake on Dec. 24 measured 2.4.
There is “little doubt” that the quake is linked to injection wells that the state and the owner agreed on Friday to shut down, Hansen said.
James Zehringer, director of the Ohio Department of Natural Resources, announced the closing of two injection wells in Youngstown Township owned by Northstar Disposal Services LLC and operated by D&L Energy Inc.
The order to close came despite the fact that the state has been unable to prove that the wells, which are 9,000 feet deep, are the cause of the earthquakes.
The wells were used to dispose of salty brine wastes from gas and oil drilling by pumping them under pressure into rock formations deep underground.
The wells are among 177 in Ohio. Drilling wastes from Ohio and Pennsylvania are being pumped in increasing volumes into the wells for permanent disposal.
Geologists have long suspected that injecting liquids into underground rock formations can trigger earthquakes along fault lines. The liquids allow rocks to flow more easily past each other.
Earthquakes have been linked to injection wells in Arkansas, West Virginia, Colorado and Texas.
The Ohio closing order took effect at 5 p.m. Friday but there would still have been pressure inside the two wells that could have triggered the quake, Hansen said.
The latest quake appears to have been located about two- thirds of a mile from the injection wells and about 1.2 miles below ground, he said.
This quake shows all the similarities of the 10 previous Youngstown quakes in 2011, he said.
Ohio also worked with scientists from Columbia University who had installed four seismographs near the site.
The first two Youngstown earthquakes occurred on March 17 and measured 2.1 and 2.6.
The state became suspicious of the injection wells after the initial quakes, which are unusual events in the Youngstown area, he said.
Earthquakes smaller than 4.0 generally do little damage. A 4.0-magnitude quake would release 40 times the energy of a 2.7 magnitude quake.
Forney rode out the quake sitting on her couch.
She and friends were puzzled by what had happened. “We wanted to know: What is this?” she said. “What’s going on? We didn’t know. We just felt the trembling.”
Bob Downing can be reached at 330-996-3745 or firstname.lastname@example.org.