Editor's note: The magnitudes for the Pawnee earthquake and the Prague earthquake were both upgraded by the USGS on Sept. 7, 2016. The Pawnee quake was upgraded to 5.8. The Prague quake was upgraded to 5.7.
An earthquake matching the largest in state history rattled Oklahoma and neighboring states Saturday morning, damaging buildings and leading Gov. Mary Fallin to issue a state of emergency for Pawnee County.
The quake prompted state oil and gas industry regulators to order the shutdown of disposal wells in a more than 700-square-mile area near the quake’s epicenter.
The 5.6-magnitude temblor was based about 8 to 9 miles northwest of Pawnee, striking at 7:02 a.m., according to the U.S. Geological Survey. The earthquake matched the largest recorded in state history, which struck near Prague in Lincoln County in 2011.
After Saturday’s quake, the Oklahoma Corporation Commission issued orders to shut down indefinitely 37 oil and gas disposal wells in a 725-square-mile area near Pawnee County, about 60 miles northwest of Tulsa.
Fallin issued a state of emergency for Pawnee County on Saturday evening. The order gives state agencies permission to purchase materials for disaster relief. It’s also the first move in securing federal funds, if necessary, according to a news release from the governor’s office.
“I’m glad to hear no one was seriously hurt in today’s earthquake and damage appears to be limited. This emergency declaration will start the process to helping individuals, families and businesses impacted by the earthquakes and serves as a precursor to requesting any necessary assistance,” Fallin said in the release.
The order lasts 30 days, and additional counties could be added, according to the release.
At least one person was injured in the quake, the Pawnee Fire Department reported Saturday. At least three homes within Pawnee County Emergency Management’s jurisdiction were damaged, and three buildings were damaged within Pawnee city limits, according to the Oklahoma Department of Emergency Management release.
Minor damage to two structures — one of which was a municipal building — was reported in nearby Lincoln County, the release states.
Pawnee Mayor Brad Sewell was fixing breakfast when what he described as a movie scene began unfolding — trinkets falling from shelves, floors undulating and the entire house shaking.
“It sounded like, if you can imagine, crumbling or thunder or some big explosion,” Sewell said.
In the past, the Pawnee area had felt only brief tremors, Sewell said. The temblor Saturday morning shook for an extended period.
Sewell expressed concerns about potential damage to the significant number of old buildings, saying one of the top assets of Pawnee is its historic structures. Many of the older buildings in the downtown area were cordoned off by authorities awaiting an inspector to assess structural integrity.
The most visible exterior damage in downtown occurred to the historic sandstone building on the corner of Sixth and Harrison, which opened in 1902 as Pawnee’s original bank. A number of stones from the building’s upper facade tumbled to the sidewalk.
The vacant building, which is on the National Register of Historic Places, is owned by Joyce Cheatham and her husband, who have been looking to sell it. The pair had undertaken some renovations, and she said caulking that had just been put in recently hasn’t pulled off the building.
“As far as we can tell there’s no cracks that are any worse than they used to be,” Cheatham said.
A few blocks away, employees of White’s Foodliner worked feverishly with family and friends who were helping to clean up the earthquake’s substantial mess — aisles packed with items piled a foot high on the floor.
Large ceiling tiles fell, but the two employees inside were uninjured.
Produce manager Buddy Richards was filling the store’s potato bin when the shaking began. Almost in a state of disbelief, he found odd humor in the chaos as everything fell around him.
“The coolers, all the stuff on the wall, the boxes on the end, the beer, the pop — every aisle was full all the way down,” Richards said.
Outside of damage to homes and other buildings, the Oklahoma Corporation Commission has reported no damage to pipelines and other fuel infrastructure.
Cushing’s critical oil pipeline infrastructure remains sound and operational as normal, Corporation Commission spokesman Matt Skinner said.
All 180 bridges within a 30-mile radius of the quake’s epicenter are open and safe for travel, the Oklahoma Department of transportation reported. Inspectors found minor cosmetic damage on two bridges.
Preliminary information from the Oklahoma Geological Survey indicates the earthquake was a “strike-slip event” off the southern edge of the Labette Fault, a major fault that runs through Pawnee and into Osage County.
Since the 5.6 temblor struck, the Pawnee area has experienced 10 aftershocks, ranging in magnitude from 2.6 to 3.6, according to U.S. Geological Survey data.
These aftershocks could continue for a few days to a few years, and there is about a 5 percent chance that any aftershocks will be larger than the initial 5.6, according to the Oklahoma Geological Survey’s fact sheet.
The survey warns that if residents observed damage to their homes, further damage from aftershocks is possible.