GRN Reports:

Something’s not right in Oklahoma.

Guthrie, Oklahoma shook in a larger than average 4.2 magnitude earthquake on Aug. 19. But…this was just one of dozens of earthquakes to rumble across the state this year.

Oklahoma has earthquakes, albeit non-injurious ones, regularly. To give you an idea: Oklahoma had 25 earthquakes in five days in mid-August, according to government statistics kept by the US Geological Service.

Oklahoma Earthquake Aug. 19, 2014

Highlighted area shows Aug. 19 earthquake.

That’s because the Sooner State, like a few others currently being aggressively drilled for natural gas, is experiencing earthquake “swarms.”

This is how people are now referring to the cluster of earthquakes that have popped up in Oklahoma, Texas, Arkansas and even Ohio in regions that are all curiously close to natural gas drilling hot spots. Many of these areas quiver regularly with small, but detectable earth shakes. People in Azle outside Fort Worth have been angered by the continuing minor, but sometimes damaging, quakes. People in the Eagle Ford oil and natural gas region, south of Austin, could face similar issues, though now in that area, air pollution and water scarcity related to drilling is the greater concern.

Oklahoma’s swarms fit that mode of being close to fracking activity, and are most likely caused by fracking water injection wells, according to several scientists, including OU researcher Katie Keranen.

Studies in Texas also have shown that the quakes are close to the injection wells, and vice versa.

The sheer numbers of mini-quakes occurring amid the shale boom makes a compelling case that something’s gassy about this trend.

Oklahoma has experienced more earthquakes in the last 5 years than in the previous 40. (See the red dots on the map below.)

But while the circumstantial evidence looks like these two things – earthquakes and injections wells – are causally correlated, the oil and gas industry has not claimed responsibility.

Oklahoma earthquakes....more now than before

Red marks earthquakes since 2009. Blue is earthquakes from 1970-2009.

Industry officials note that there was a rash of earthquakes in the Sooner state in the 1950s (which I’ve chronicled below). Oklahoma, they say, might just be earthquake prone.

On Aug. 19, 2014, it was quite prone.

Most of the swarm-y earthquakes are in the 2 to 3 magnitude territory. The more emphatic Guthrie shake rattled windows and knick-knacks all the way into Oklahoma City, 24 miles to the south. Later, an aftershock reminded everyone that this was not their imagination.

Earthquakes of the 1950s and 1960s in Oklahoma

  • 1952 (April 9): A 5.5 magnitude earthquake center near El Reno was felt across the state, and as far away as Iowa. Damage was not extensive, according to the USGS, but people “were alarmed” because bricks became loosened in buildings, plate glass windows broke in El Reno and there were aftershocks.

    Shale Gas Plays in Southern US

    Areas of shale gas drilling in Oklahoma and other states.

  • 1956 (Feb. 16): An earthquake centered in Edmond was also felt in Guthrie. Later that year, shocks hit Antlers and also Northeastern Oklahoma. These shakes produced loud “bumping noises,” according to government records. After the shake in northeastern Oklahoma an oil well had to be shut down because of damage. That’s right, these earthquakes were occurring in state with oil-drilling regions.
  • 1959: A earthquake caused slight damage to walls and pavement across a swath of southwestern Oklahoma on June 17.
  • 1961: Back in Southeastern Oklahoma, a mild shake was felt in Latimer and Pittsburgh Counties on Jan. 10. Later on April 27, another earthquake shook Antlers, Coalgate, and several other small towns. Residents reported hearing deep rumbling throughout the area.
  • 1968: A fall earthquake hits Durant, knocking canned goods from a shelf and cracking some glass in buildings.
  • 1969 (May 2): A 4.6 magnitude earthquake cracked plaster at Wewoka. It was felt across much of eastern Oklahoma.