Small earthquake strikes near Oklahoma City: Is fracking to blame?
Wednesday, June 18, 2014, 7:10 PM - A magnitude 4.1 earthquake struck about 12 km northeast of Oklahoma City at 5:53 a.m. local time Wednesday, according to the U.S. Geological Survey (USGS).
Some residents reported shaking but no damages or injuries have been made apparent.
The quake appears to have been the finale to a series of tremors that jolted the region beginning late Tuesday evening.
According to local media, a magnitude-2.7 quake was reported at 5:30 a.m. southeast of the community Edmond, Oklahoma. Approximately three hours prior, a magnitude-3.0 quake was recorded near Langston.
Magnitude 2.7 quakes were reported in three separate communities late Tuesday evening as well.
The recent round of seismic activity is something that's becoming increasingly common in Oklahoma, and that has some experts concerned.
In May a U.S. Geological Survey and Oklahoma Geological Survey analysis revealed that 145 earthquakes of magnitude 3.0 or greater occurred in Oklahoma between January and May 2, 2014, replacing the previous annual record of 109 earthquakes set in 2013.
The spike in activity is massive: Between 1978 and 2008, the state saw an average of only two earthquakes measuring a magnitude 3.0 or more each year.
“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, in a statement.
WHAT IS CAUSING THE SPIKE IN ACTIVITY?
Experts suspect the increase in seismic activity is linked to fracking, or hydraulic fracturing.
This process involves injecting a mixture of water, chemicals and sand deep into the ground to extract natural gas from shale rock.
"This phenomenon is known as injection-induced seismicity, which has been documented for nearly half a century, with new cases identified recently in Arkansas, Ohio, Texas and Colorado," The USGS writes.
"A recent publication by the USGS suggests that a magnitude 5.0 foreshock to the [magnitude-5.6] 2011 Prague, Okla., earthquake was human-induced by fluid injection; that earthquake may have then triggered the mainshock and its aftershocks ... studies also indicate that some of the earthquakes in Oklahoma are due to fluid injection."
The Prague earthquake was the largest in Oklahoma’s history, damaging a number of homes and buildings.
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