Seismic Side Effects

The horizontal drilling technique known as fracking has spawned an energy revolution in the U.S., driving down the cost of natural gas, unlocking vast reserves of shale oil and powering America towards our long-sought goal of energy independence.

But hydraulic fracturing also may be spawning earthquakes–lots of them–in places that don’t normally have them.

Oklahoma is among at least four U.S. states with extensive drilling operations which have suddenly started to shake, rattle and roll on a regular basis since fracking operations commenced in their territory. In the past week, at least 115 earthquakes of varying intensities have hit the Sooner State. According to reports, most of the quakes in a swarm of temblors between Oklahoma City and Guthrie, OK have been accompanied by a loud explosive sound that’s been likened to a thunderclap or cannonball.

According to earthquake monitors EQ Charts, between 1990 and 2008 there were between 0 and 11 earthquakes annually in the OKC-Guthrie area with magnitudes of 2.0 or greater on the Richter Scale. In 2009 there were 49; in 2010, 180; in 2013, 291. Barely two months into 2014, 59 quakes of 2.0 or bigger already have hit, with dozens of mini-quakes as well. In 2011, central Oklahoma experienced a magnitude-5.7 quake, the most powerful ever recorded in the state [each point on the Richter Scale represents a tenfold increase in the power of a quake].

Hydraulic fracturing (a.k.a. fracking) involves drilling a horizontal shaft deep beneath the surface and then blasting it with water and chemicals to force out pockets of natural gas or oil. Scientists now trying to determine if there’s a connection between fracking and earthquakes are focusing on two aspects of the drilling operations: the drilling itself, which can be explosive, and the post-drilling practice of injecting spent drilling water back into the ground for storage at high pressure.

At this point, a consensus seems to be emerging that the earthquake problem is not being caused by the initial drilling operations but rather by post-drilling injection of wastewater.

“It’s not the fracking itself, it’s this re-injection of the fluids into formations that are considered safe to hold it,” Don Blakeman, a geophysicist with the National Earthquake Information Center in Golden, CO, told the Wichita Eagle.

The earthquake outbreak in Oklahoma comes just a few weeks after a similar shake-fest centered in the Azle, TX area north of Fort Worth. More than 30 earthquakes are said to have rattled Azle since November. Late last month, a group of area residents said they’d had enough: 100 of them turned up at a meeting of the Texas Railroad Commission in Austin to protest the situation (the TRC regulates mineral energy production in Texas).

“No disrespect, but this isn’t rocket science here,” testified Reno, TX Mayor Lynda Stokes, according to a report on “Common sense tells you the wells are playing a big role in this.”

Sharon Wilson of the Earthworks Oil and Gas Accountability Project, an environmental group, declared at the hearing: “The correlation of increased fracking wastewater disposal and increased earthquakes is blindingly obvious.”

The fracking-followed-by-earthquakes phenomenon has stretched all the way up to Ohio, which is home to a significant portion of the Marcellus Shale Formation, one of the richest natural gas reserves in the nation (containing an estimated 13.8 trillion cubic meters of gas, which is 440 times the amount consumed annually by the state of New York).

On December 31, 2011 a magnitude-3.9 earthquake struck near Youngstown, OH, a location that previously had no record of ever having an earthquake. Last September, NBC News reported that researchers had linked the Youngstown quake to nearby fracking operations. In research papers published in the scientific journal Geophysical Research Letter and the Journal of Geophysical Research, scientists tied the Dec. 31 quake–and 167 smaller temblors that afflicted the Youngstown area in prior months–to Northstar 1, an injection well that came online in Dec. 2010 to pump wastewater from fracking projects in Pennsylvania into a deep storage facility in Ohio.

According to the research papers, the first earthquake was recorded in Youngstown 13 days after pumping began at the Northstar facility. The earthquakes ceased a few weeks after the Ohio Department of Natural Resources shut down the Northstar well at the end of 2011. Cessation of earthquake activity in the area also was noted by the team to coincide with national holidays in 2010 and 2011, when injection at the 9,200-foot-deep Northstar well temporarily was halted. When the well was finally shut down by the state, more than 495,000 barrels of wastewater had been injected into it.

The researchers theorized that pressure from the Northstar injections had caused an ancient fault line in the area to rupture. However, they also noted that Northstar was the only one out of 177 similar wastewater wells active in Ohio to be linked to seismic activity, which suggests that this connection may be rare.

“We conclude that the recent earthquakes in Youngstown, OH were induced by the fluid injection at a deep injection well due to increased pore pressure along the preexisting subsurface faults located close to the wellbore,” Won-Young Kim, a researcher at Columbia University, wrote in the paper published in the Journal of Geophysical Research.

The growing concern about potential side effects from fracking has moved even some state officials long considered friends of the oil and gas industry to take preventive measures.

Gov. Rick Perry of Texas pushed through the first law in the nation requiring fracking operations to disclose the chemicals used in the drilling. In Kansas, Gov. Sam Brownback last month appointed a committee to study whether oil and gas drilling activity caused a recent flurry of minor earthquakes in his state. Brownback said the study was needed as a “matter of public safety.”

Caldwell, KS, near the Kansas-Oklahoma state line, has had three earthquakes in the past two months, ranging in magnitude from 3.3 to 3.9.

According to the report in the Wichita Eagle, Gov. Brownback’s team in Kansas is hampered because traditionally the U.S. Geological Survey has only maintained two earthquake-monitoring stations in the entire state. Tornados, not earthquakes, always have been the primary concern in the Sunflower State.

We don’t know how long it will take to resolve this problem or what the fix will be (a national nuclear/fracking waste depository under Yucca Mountain?), but one thing seems certain:

The residents of Azle, TX (pop. 11,000) will keep making noise until something gets done. According to the Fort Worth Star-Telegram‘s account of the town’s protest at the Railroad Commission meeting, when the commissioners started droning on about safety records an Azle denizen pulled out a guitar and broke into a rendition of Elvis Presley’s All Shook Up.

That leaves us with only one thing left to say. Thank you. Thank you very much.