These have been linked to underground disposal of wastewater from fracking, reported The Oklahoman.
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Although the number of earthquakes in 2016 seems to be slowing down slightly, experts are still pointing to oil and gas production as a reason for the increase in seismic activity in recent years.
The U.S.G.S. says at least ten additional quakes have struck near Pawnee, ranging from 2.7 to 3.6 in magnitude.
The quake, which struck 14 km (9 miles) northwest of Pawnee in north-central Oklahoma at 7:02 a.m. CDT (1302 GMT), had a magnitude of 5.6, matching in strength a temblor that hit the state in 2011, the United States Geological Survey reported on its website.
Pawnee County Emergency Management posted photos on Facebook just before noon of a pile of rubble, noting that three buildings had moderate damage, while several others had minor damage.
The damage is not as severe as that caused by the 2011 quake near Prague, Okla., about 60 miles south of Pawnee, despite being the same magnitude and approximately the same depth below the surface. Steve Gibson, a retired state trooper and longtime resident of Pawnee, was outside checking the damage to that building, which had been roped off with police tape.
A 5.6 magnitude natural disaster struck Saturday morning near Pawnee, Oklahoma, and rattled through at least six surrounding states in the US heartland, according to the US Geological Survey. Many people also report feeling tremors in the St. Louis area.
The disposal of wastewater produced from fracking, has led to the alarming increase of earthquakes with magnitude-3 or larger by almost 300 times, or 30,000 percent in north-central Oklahoma alone.
Before 2008, Oklahoma typically experienced one or two noticeable earthquakes per year.
Earlier this year, state regulators curbed the amount of wastewater that the oil and gas industry can inject thousands of feet into the Arbuckle formation, a sedimentary rock layer found under Oklahoma that rests above fault lines.
“If you’re in a taller building, it’s going to sway a lot more”, he said, explaining the effects of a magnitude-5.6 quake.
Oklahoma Corporation Commission, the state agency that oversees drilling, was contacting all disposal well operators in the area of the quake, telling them to shut down their wells, according to OCC Public Information Director Matt Skinner.
CNN reported that the event also rattled Kansas, Arkansas, Missouri, Texas, Nebraska, and Iowa, citing geophysicists with the U.S. Geological Survey (USGS), who said it “occurred as the result of shallow strike-slip faulting”. “I kind of think it’s good luck”.
In Southwest Oklahoma, residents reported creaking ceilings and walls, swinging chandeliers and swaying beds as the energy from the quake 150 miles away rudely awakened them.
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The epicenter of the quake was in Pawnee. Residents in Fort Smith, Arkansas, could feel the quake.
