It would seem as though Oklahoma finally took a mighty shiver as the state is set to exit several days of subfreezing temperatures.
The U.S. Geological Survey recorded a 4.2-magnitude earthquake about 4 miles southwest of Manchester, north of Enid on the Kansas state line, just before 8 a.m. Friday.
Preliminary reports indicate that the quake was about 4.35 miles deep and followed a 2.9-magnitude earthquake Thursday night southeast of Jefferson, about 40 miles away.
Most people who felt Friday’s quake were within 150 miles of its epicenter, according to the USGS’s Did You Feel It? data collection program. Early data almost painted a triangle of residents reporting weak to moderate shaking in and between Tulsa, Oklahoma City and Salina, Kansas.
The measured magnitude stopped short of being comparable with Oklahoma’s greatest recorded earthquakes. A 5.8 in Pawnee County in 2016 holds the record.
Friday’s quake was initially measured at 4.8, which would have tied it for the seventh-largest recorded in the state along with three other previously recorded quakes — near Fairview in 2016 and Prague twice in 2011 — but it was later revised to 4.5 and eventually 4.2.
In response to Friday’s earthquake, the Oklahoma Corporation Commission’s Induced Seismicity Department has directed operators of certain disposal wells in the region to cease operation or reduce volume, the commission announced Friday afternoon.
Oil and gas wastewater disposal wells that inject into the Arbuckle formation within 3 miles of the earthquake’s epicenter were directed to cease operation. Those within 3 to 10 miles of the epicenter were directed to reduce disposed volume to no more than 50 percent of their most current 30-day average.
The Corporation Commission estimated that these actions will reduce disposed volumes by about 7,000 barrels a day.
“Researchers are in broad agreement that disposal into the Arbuckle formation in parts of Oklahoma can raise risk of induced seismicity,” the commission said in a statement. “Commission ISD directives since 2015 limiting or eliminating such disposal are among the actions credited with the sharp decrease in Oklahoma’s seismicity rate since 2015.”
The number of 3.0-or-greater earthquakes in Oklahoma — almost unheard of in earlier years — increased from two in 2008 to 20 the next year and 41 in 2010 as the amount of wastewater injection in the state increased. The numbers continued to climb until reaching 903 in 2015, the Oklahoma Geological Survey has reported.
Oklahoma last experienced a 4.2-quake two weeks ago, Feb. 5, near Lucien, in Noble County west of Perry. Although its depth measured only 0.18 miles closer to the earth’s surface than Friday’s shudder, far fewer residents reported feeling that quake.
A 4.2 magnitude also occurred June 20, 2020, near Perry. A 4.4 was recorded near Medford in 2019.
Video: Winter tips for water safety, staying safe outside
Oklahoma’s largest quakes since 1882, ranked
Oklahoma's largest earthquakes since 1882, ranked
On Nov. 6, 2011, a milestone 5.7 magnitude earthquake recorded in Lincoln County in central Oklahoma.
It was topped five years later by a 5.8 magnitude temblor on Sept. 3, 2016, which led then-Gov. Mary Fallin to issue a state of emergency for Pawnee County, and 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.
Insurers paid out $1.5 million in claims related to the 2011 Prague earthquake, which at the time was the most in seismicity damages paid in Oklahoma for a single event, according to Insurance Department data analyzed by the Tulsa World.
Here are the largest earthquakes in the state by county, according to the Oklahoma Geological Survey.