One of the largest earthquakes in Oklahoma rattled the Midwest on Saturday from Nebraska to North Texas, and likely will turn new attention to the practice of disposing oil and gas field wastewater deep underground.
The United States Geological Survey said a 5.6 magnitude earthquake happened at 7:02 a.m. Saturday in north-central Oklahoma, a key energy-producing region. That matches a November 2011 quake in the same region. No major damage was immediately reported.
People in Kansas City and St. Louis, Missouri; Fayetteville, Arkansas; Des Moines, Iowa; and Norman, Oklahoma, all reported feeling the earthquake. Dallas TV station WFAA tweeted that the quake shook their studios, too.
An increase in magnitude 3.0 or greater earthquakes in Oklahoma has been linked to underground disposal of wastewater from oil and natural gas production. State regulators have asked producers to reduce wastewater disposal volumes in earthquake-prone regions of the state. Some parts of Oklahoma now match northern California for the nation's most shake-prone, and one Oklahoma region has a 1 in 8 chance of a damaging quake in 2016, with other parts closer to 1 in 20.
A cluster of quakes in northwestern Oklahoma this year included a magnitude 5.1 earthquake, and several 4.7 quakes were felt last fall before regulators stepped in to limit disposal activity.
Saturday's quake was centered about 9 miles northwest of Pawnee, Oklahoma. Earlier this week, the same spot, which is about 70 miles northeast of Oklahoma City, saw a magnitude 3.2 temblor.
Sean Weide in Omaha, Nebraska, told The Associated Press that he'd never been in an earthquake before and thought he was getting dizzy. Weide said he and one of his daughters "heard the building start creaking" and said it "was surreal."