For the past thirty years, Oklahoma has averaged about 50 earthquakes per year. However, records indicate that this number has begun to skyrocket in recent times. In fact, there have been 3,000 seismic events in 2013 alone, which is making residents of the state very nervous.
The earthquakes tend to be small and are mostly located in the center of the state. The current data provided on the Oklahoma Geological Survey website indicates that 41 earthquakes have occurred during the past seven days, with magnitudes ranging between 1.3 and 3.2.
Earthquakes with magnitudes of 2.5 or less are generally not felt and can only be detected with a seismograph, a device which is designed to detect and measure earthquakes. Those which are in the range of 2.5 to 5.4 may be felt, but do not cause any significant damage. Earthquakes ranging between 3.0 and 3.9 are considered to be “minor” earthquakes.
In October the U.S. Geological Survey put out a warning that the state’s risk of earthquakes had increased by a factor of ten. And, in 2011, the state had it’s largest earthquake ever: a 5.6 magnitude quake which hit the area east of Oklahoma City.
A senior science advisor at USGS named Bill Leith says this rise in seismic activity doesn’t necessarily mean that a large earthquake is imminent, but the chances of it happening do go up quite a bit.
According to Leith, there is some evidence which links the Oklahoma earthquakes to the state’s oil and gas industry. When drilling occurs, toxic fluid from hydraulic fracturing, also known popularly as fracking, is injected into the ground. This can create pressure near fault lines, triggering seismic activity.
Unfortunately, while this theory sounds quite reasonable to many scientists, there is no proof. Because of this, no moves have been made to create regulations related to fracking.
NPR reports that in the fall state regulators did force drillers along the Oklahoma-Texas border to reduce injection volume and pressure after a nearby series of earthquakes.
While seismologist Austin Holland, who tracks earthquakes for the Oklahoma Geological Survey, says that it can’t be proven at this point whether fracking and earthquakes are related, he believes it would be “a pretty remarkable coincidence” if they aren’t. What Holland proposes to resolve the issue is to inject pressurized water into porous rock in an earthquake-prone location to see if it sets off anymore quakes. The test would be monitored by Holland and the Oklahoma Geological Survey.
The oil and gas industries are quite nervous about adding new regulations which could have adverse effects on their bottom line, say experts. Oklahoma is the fifth-largest old producer in the country. If it is proven that fracking is causing the current swarm of earthquakes, it could have serious impacts on their profits as property owners seek to sue them for the damages caused by the quakes.
While it remains unclear why earthquakes are beginning to skyrocket in Oklahoma, nervous residents can only hope that scientists solve the problem soon. If fracking is proven to be cause of the increased seismic activity, then people will probably begin to push very hard for legislation to minimize the risks associated with it.
By Nancy Schimelpfening