Magnitude-4.0 Earthquake Shook Eastern Ohio Saturday

A magnitude-4.0 earthquake shook eastern Ohio at 3:05 p.m. on Saturday, the U.S. Geological Survey reported.

The latest quake struck only a week after a smaller tremor shook the region.

The earthquake's epicenter was two miles northwest from Youngstown, the USGS reported. And it was 55 miles east-southeast of Cleveland and 145 miles northeast of Columbus, according to CNN.

The USGS reported the quake struck at a depth of 3.1 miles.

Michael C. Hansen, state geologist and coordinator of the Ohio Seismic Network, part of the Ohio Department of Natural Resources' Division of Geological Survey, told Ohio.com that the quake was felt as far away as Michigan, Pennsylvania, and New York in the United States and Ontario in Canada. [It was] a pretty good-sized one, Hansen said.

According to The Associated Press via USA Today, officials on Saturday said they believe the latest earthquake activity is related to the injection of wastewater into the ground near a fault line that created enough pressure to cause seismic activity.

A day ago, James Zehringer, director of the Ohio Department of Natural Resources, said work would be halted on a fluid-injection well in Youngstown. This move was made because of fears that the well work could be causing the recent apparent increase in seismic activity in the area, according to CNN. The report noted that the decision was made after state officials brought in experts from Columbia University to collect information about seismic activity in the area.

An injection well is a device that places fluid deep underground into porous rock formations, such as sandstone or limestone, or into or below the shallow soil layer, according to the U.S. Environmental Protection Agency.

The AP reported that the brine wastewater comes from drilling operations using the fracking process to extract gas from underground shale.

Zehringer has said that the fracking is not the cause of the quakes.

The seismic events are not a direct result of fracking, he said, as reported by the AP.

Ohio.com reported that the recent quake was the 11th to occur during the last eight months in Mahoning County. They were reportedly all within two miles of the injection wells. A quake on Dec. 24 reportedly measured 2.4. The first two Youngstown earthquakes happened on March 17 and reportedly measured 2.1 and 2.6, according to Ohio.com.