In 2009, after decades of little or no serious seismic activity, the number of earthquakes in Oklahoma began tor rise. In 2011, a 5.6 Mag Quake Rattled Oklahoma, which was the strongest quake in that state’s history. Since then, the number of quakes has continued to increase, which has been the subject of several blogs here at AFD.
While 2013 was a record year for Oklahoma quakes over M3.0, the first 5 months of 2014 have produced quakes at more than twice last year’s rate, leading the USGS and the Oklahoma Geological Survey (OGS) to issue a joint statement on the ongoing earthquake risk in that state.
First a link, and a few excerpt from that statement, after which I’ll return with more.
The rate of earthquakes in Oklahoma has increased remarkably since October 2013 – by about 50 percent – significantly increasing the chance for a damaging magnitude 5.5 or greater quake in central Oklahoma.
A new U.S. Geological Survey and Oklahoma Geological Survey analysis found that 145 earthquakes of magnitude 3.0 or greater occurred in Oklahoma from January 2014 (through May 2; see accompanying graphic). The previous annual record, set in 2013, was 109 earthquakes, while the long-term average earthquake rate, from 1978 to 2008, was just two magnitude 3.0 or larger earthquakes per year. Important to people living in central and north-central Oklahoma is that the likelihood of future, damaging earthquakes has increased as a result of the increased number of small and moderate shocks.
Oklahoma’s heightened earthquake activity since 2009 includes 20 magnitude 4.0 to 4.8 quakes, plus the largest earthquake in Oklahoma’s history – a magnitude 5.6 earthquake that occurred near Prague on Nov. 5, 2011. The 2011 Prague earthquake damaged a number of homes and the historic Benedictine Hall at St. Gregory's University in Shawnee. Prior to the 2011 Prague earthquake, the largest earthquake of Oklahoma’s history was a magnitude 5.5 earthquake that occurred in 1952 near El Reno and damaged state buildings in Oklahoma City.
“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.”
While no specific predictions as to time, location, or intensity are offered, these agencies believe there is a heightened risk for larger, potentially damaging earthquakes in Oklahoma – at least in the near term.
The bottom line is that Oklahomans (and anyone else who lives an a seismically active region) need to seriously include earthquake preparedness as part of their overall emergency plans.
The State of Oklahoma maintains an earthquake safety webpage at EARTHQUAKE SAFETY, while additional Oklahoma specific earthquake monitoring and research information can be found at the Oklahoma Geological Survey.
Although the west coast is most noted for its seismic hazards, much of America’s heartland and parts of the Eastern Seaboard are also susceptible to moderate to strong quakes. A topic I covered more than a year ago in USGS: Eastern Earthquakes - Rare But Powerful.
At a bare minimum, every household should have a disaster plan, a good first aid kit (and the knowledge to use it), an emergency battery operated NWS weather radio, and emergency supplies to last a minimum of 72 hours during a disaster.To become better prepared as an individual, family, business owner, or community, I would invite you to visit the following preparedness sites.
AMERICAN RED CROSS http://www.redcross.org/
For more on increasing your level of preparedness, a partial list of some of my preparedness blogs include: