The Oklahoma Geological Survey (OGS) and the Induced Seismicity Department at the Oklahoma Corporation Commission (OCC) continue to investigate this morning's earthquake activity in the Stroud area.
Preliminary data from the United States Geological Survey (USGS) shows 6 events in the area, beginning at 8:47 a.m.
An oil and gas field inspector is in the area as part of the investigation.
The area is within the main earthquake Area of Interest (AOI) where oil and gas wastewater disposal into the Arbuckle formation has been sharply reduced.
There is no new well activity in the area in terms of drilling or hydraulic fracturing.
The OCC is currently reviewing the operations of 8 Arbuckle disposal wells that are within 10 miles of the preliminary epicenters of the events.
OGS reports initial data indicates the first earthquake had a magnitude of 4.2 (+ or - 0.1) at a depth of 9.3 Kilometers (5.77 miles). It occurred in Northeast Lincoln County and is the 3rd 4.0 or greater quake of 2017. By comparison there were 15 4.0 or greater quakes last year and 27 the year before. Including the preliminary data on today's events, there has been a total of 26 earthquake events of 2.7 or greater in Oklahoma in July thus far, compared to 106 in for all of July 2016 and 169 in for all of July 2015.