Chance of Damaging Earthquake in Central Oklahoma Increasing Says USGS

Posted on May 6, 2014

Chart of magnitude 3.0 earthquakes in Oklahoma since 1978

USGS says in an advisory that the chance of a damaging earthquake, of magnitude 5.5 or greater, has significantly increased. The rate of earthquakes has jumped over 50% since October 2013. USGS says a new survey found there have been 145 earthquakes of magnitude 3.0 or greater in Oklahoma since January 2014. The previous annual record for earthquakes was 109 in 2013. They also note that there have been 20 magnitude 4.0 to 4.8 earthquakes since 2009. This also included the largest earthquake in Oklahoma history, a 5.6 on November 5, 2011 that occurred near Prague.

Dr. Bill Leith, Senior Science Advisor for Earthquakes and Geologic Hazards at USGS, says in a statement, "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. Building owners and government officials should have a special concern for older, unreinforced brick structures, which are vulnerable to serious damage during sufficient shaking."

Oklahoma Seismicity from 1970 to end of April 2014

USGS says in the advisory that injection-induced seismicity is likely contributing to the increase in earthquakes. A 5.0 foreshock to the 2011 Prague earthquake was linked to active fluid injection wells.

Images: USGS