MEDFORD, Okla. (AP) – An earthquake that rattled parts of northern Oklahoma and southern Kansas has been upgraded to magnitude 4.3.
The U.S. Geological Survey initially reported the quake as magnitude 3.9 after it struck at 9:26 p.m. Thursday near Medford, Oklahoma, about 90 miles north of Oklahoma City.
The USGS upgraded the magnitude Friday after further review.
Grant County Emergency Management Director Brandon Fetters called the quake “stout,” but said there are no injuries or damage.
Thousands of earthquakes have been recorded in Oklahoma in recent years, with many linked to the underground injection of wastewater from oil and natural gas production operations.
State regulators have directed oil and gas producers to close some wells and reduce injection volumes in others.