Oklahoma's strongest ever earthquake is felt across seven states after experts warned fracking could lead to increase in seismic activity.
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.
The USGS outlined the risk of the 'induced' earthquakes, and noted that Oklahoma City and the region surrounding face a five to 12 per cent chance of damage from an earthquake in 2016.
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.
Oklahoma saw a spike in earthquakes in 2009. An estimated 890 quakes happened in the state last year, as at least 30 of them measured 4.0 or greater magnitude, according to the USGS.
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.'
State regulators have asked producers to reduce wastewater disposal volumes in earthquake-prone regions of the state.
According to a recent report released by theUSGS, Oklahoma faces similar ground-shaking risks from human-induced activity, including fluid injection or extraction, which is creating a risk similar to that of what people in California face from natural earthquakes in that state.
Commission spokesman Matt Skinner says the wells were directed to shut down due to scientific links that the increase to the underground disposal of wastewater from oil and gas production induces earthquakes. The commission has previously asked producers to reduce wastewater disposal volumes. Officials at a nuclear power plant in the southeast corner of Nebraska say tremors from the Oklahoma earthquake were felt at the plant.
Nebraska Public Power District's Cooper Nuclear Station south of Brownville declared an 'unusual event' just after 7am because of the minor tremors.
OKLAHOMA'S TOP 5 STRONGEST EARTHQUAKES
Here's a list of the top five strongest earthquakes that have happened in Oklahoma.
September 3, 2016 in Pawnee; 5.6 magnitude
November 6, 2011 in Prague; 5.6 magnitude
April 9, 1952 in Yukon; 5.5 magnitude
February 13, 2016 in Woods County; 5.1 magnitude
November 22, 1882 in Durant; 4.9 magnitude
Source: Oklahoma Geological Survey
Officials say there was no damage to the plant or equipment, and no threat to the public or plant personnel occurred.
The plant continued operating Saturday, but station personnel increased monitoring of plant equipment, per the plant's policy.
Station emergency preparedness manager Jim Stough says the nuclear station was built to withstand some earthquakes and other scenarios that are likely to occur in the region.
Officials say local, county, state, and federal agencies were notified of the event.
White's Foodliner store in Pawnee is closed for the day after the quake shook items off of the store shelves and onto the floor.
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.
Saturday's quake was centered about 9 miles northwest of Pawnee, Oklahoma, which has a population of about 2,200.
Oklahoma's strongest ever earthquake is felt across seven states after experts warned fracking could lead to increase in seismic activity. 
