EDMOND, Okla., July 30 (UPI) -- A pair of earthquakes hit Oklahoma Wednesday morning, less than 48 hours after a slightly larger quake shook the state Monday night.
According to the U.S. Geological Survey, the first of Wednesday's earthquakes occurred at roughly 11:20 a.m. local time about 18 miles northeast of Oklahoma City, with a 3.4 magnitude and two-and-a-half mile epicenter.
Twenty-five minutes later, at the same location, a 3.3 magnitude earthquake shook the area, this time with a slightly deeper three mile depth.
The tremors come less than two days after a larger 4.3 magnitude earthquake was measured about 100 miles north near Medford, Okla. That quake was felt throughout the state from Oklahoma City all the way to Wichita, Kan.
No injuries were reported in any of these instances.
Earlier in July, Science Magazine published a study that determined the saline wastewater produced and pumped into the ground by hydraulic fracturing, or fracking, is responsible for the surge of earthquakes in Oklahoma.
Since July 2013, 878 earthquakes have struck Oklahoma.