USGS issues earthquake warning for Oklahoma

Oklahoma Seismicity Map - 1970 to April 30, 2014. Courtesy: USGS

The number of significant earthquakes in Oklahoma in 2014 has already surpassed the previous record, set in 2013. Now, the USGS is issuing a warning for the Sooner State.Since January 1, the U.S. Geological Survey and Oklahoma Geological Survey says the state has had 145 earthquakes with a greater magnitude than 3.0. In all of 2013, the state had 109 quakes. From 1978 to 2008, the state averaged two earthquakes of that size per year.Since 2009, that state has been rocked by 20 earthquakes between 4.0 and 4.8 plus the largest in the state's history, a 5.6 that occurred near Prague on Nov. 5, 2011. A number of homes were damaged in that quake including historic Benedictine Hall at St. Gregory's University in Shawnee.In response to the heightened seismic activity, the USGS is warning residents in the Sooner State that the likelihood of the state being shaken by more damaging earthquakes has increased. Now, the USGS is recommending special action for businesses and government officials."While it's been known for decades that Oklahoma is 'earthquake country', we hope that this new advisory of increased hazard will become a crucial consideration in earthquake preparedness for residents, schools and businesses in the area," said Dr. Bill Leith, Senior Science Advisor for Earthquakes and Geologic Hazards at USGS. "Building owners and government officials should have a special concern for older, unreinforced brick structures, which are vulnerable to serious damage during sufficient shaking."The USGS said it analyzed the recent earthquakes and believes they were not caused by typical, random fluctuations. Instead, the USGS believes a contributing factor of the quakes is being triggered by wastewater injection, or fracking. The OGS says it is now operating 15 permanent monitoring stations and 17 temporary ones.