On Saturday, September 3rd, an earthquake struck northern Oklahoma at around 7 am. The quake was also felt accross Kansas, Missouri, Arkansas, and Texas. The epicenter was determined to be near Pawnee, about 74 miles north of Oklahoma City at a depth of 3.7 miles.
The quake was initially measured at a 5.6 magnitude, tying the state record. After further depth analysis, the USGS has updated the reading to a 5.8, making it the largest earthquake on record in the state of Oklahoma.
This week, several smaller earthquakes struck the same part of Oklahoma. So far, there have been 8 recorded earthquakes over a magnitude of 3.0. The Oklahoma Geological Survey believes it is possible that these quakes my be linked wastewater injection wells from fracking. They are beginning a study to determine ways to reduce the chances of "inadvertently inducing a seismic event". At this time, the USGS believes the event was a result of shallow strike-slip faulting.