Another earthquake shook the ground Sunday morning near Hutchinson two weeks after a cluster of 17 earthquakes in five days.
The 3.1 magnitude hit at around 8:21 a.m. Sunday, centered about 2 miles northwest of South Hutchinson, the U.S. Geological Survey reported. It struck at a depth of about 3 miles.
The Kansas Corporation Commission announced last month that the regulatory agency launched an investigation after a swarm of 17 earthquakes hit in the same area of Reno County between Aug. 14 and Aug. 18. The investigation is focused on the underground disposal of oilfield waste that’s been blamed for quakes elsewhere in southern Kansas.
“Amid damage reports and a concern for public safety, the KCC is conducting an investigation and will evaluate whether additional action is needed to safeguard Kansans,” KCC spokeswoman Linda Berry said in a written statement announcing the investigation.
Investigators will collect data and analyze recent oilfield injection well activity in a 15-mile radius of where the earthquakes have been occurring.
The largest in that cluster were a pair of 4.2 magnitude earthquakes, the Kansas Geological Survey reported. Since the investigation started in the second half of August, five earthquakes of magnitudes between 2.0 and 2.3 struck Cowley, Dickinson Marion, Sedgwick and Sumner counties.
The study in Reno County will focus specifically on wells in the Arbuckle Formation, which has been problematic before.
Geologically placid for decades, southern Kansas began to be rocked by earthquakes in 2013, corresponding to an increase in “fracking,” an oil industry term for using high-pressure liquid to fracture subsurface rock to free trapped pockets of oil and gas.
Seismologists have ruled out fracking as a direct cause of the quakes, but the increased production it made possible generated millions of barrels of wastewater that are blamed for the increase in seismic activity.
Reno County wasn’t part of a study that led to KCC-ordered limits on wastewater disposal in 2015 and 2016. That action has been credited with calming seismic activity in Barber, Harper, Kingman, Sedgwick and Sumner counties.