CARNEY, Okla.—A magnitude 4.0 earthquake was among a series of six tremors that struck central Oklahoma on Thursday morning, according to the U.S. Geological Survey (USGS).
No injuries or serious damage were reported following the quakes that also included a magnitude 3.3 temblor and began early Thursday near the town of Carney, about 40 miles northeast of Oklahoma City.
The other quakes ranged from 1.6 to 2.3 in magnitude, according to the USGS.
“I know the earthquake was definitely felt here because I received a lot of phone calls early this morning,” said spokesperson Dawn Jones with the city of Stillwater, about 25 miles northeast of quake’s epicenter.
No damage or injuries were reported in the city, Jones said, or on the campus of Oklahoma State University, according to OSU spokesperson Shannon Rigsby.
Thousands of earthquakes of varying magnitudes have been recorded in Oklahoma during the past decade and have been linked to oil and gas production, particularly the underground injection of wastewater, which is a byproduct of oil and gas production.
The Oklahoma Corporation Commission, which regulates the oil and gas industry in the state, is sending inspectors to investigate 15 injection wells, according to spokesperson Matt Skinner.
“We’ve identified the wells that might be suspect and will audit them” for both the volume of wastewater they inject and the pressure used to inject the liquid, Skinner said.
The commission has previously directed oil and gas producers to close some injection wells and reduce volumes in others to lessen the chance of earthquakes.