Fracking and Earthquakes: Cause for Concern?

Mother Earth has some powerful weapons in her arsenal: thunderstorms, tsunamis, hurricanes, tornadoes – all tremendously powerful and known to cause devastation among those who face them. Until recently, most of this was thought to be out of human’s control. What could us little humans do to influence the weather?

Besides the emerging consensus and overwhelming scientific evidence supporting human’s influence on climate change (which leads to more severe storms and potentially much, much worse), there is growing concern over our ability to generate earthquakes. While this doesn’t have much to do with climate, our activities may be giving the earth the final push to induce an earthquake.

Our means to do so? Possibly hydraulic fracking – the practice of shooting thousands of gallons of solvents into the ground to crack open the earth and reach natural gas.

The Process of Fracking

Fracking, or hydraulic fracturing, involves several separate steps. After a natural source has been identified, the shale formation is prepared by perforating the casing by using ‘guns’ equipped with explosive charges. This is then followed up by pumping a fracturing solvent into the ‘downhole’ in order to increase pressure to exceed that of the fracture gradient of the rocks below. The result is an induced or increased flow of natural gas and/or other resources.

Evidence Suggesting Fracking Can Cause Quakes

Whether this process can actually cause earthquakes is up for debate, but recent evidence has got some people wondering. Upon reflecting on the fracking process, it obvious that the structural integrity of the shale is compromised – indeed that is the point. But can this cause a quake?

To the developers at Cuadrilla Resources, a natural gas company, hydraulic fracturing indeed does cause earthquakes – and their company has taken blame for some occurrences earlier this year. In April and May, two small earthquakes shook Blackpool, England, and many turned the suspicious eye toward the hydraulic fracturing operation. In a press release, the company took blame by stating that “It is highly probable that the hydraulic fracturing of Cuadrilla’s Preese Hall-1 well did trigger a number of minor seismic events.”

So what about here in the States?

After the very uncharacteristic and sudden quakes that hit the mostly seismically-stable Oklahoma, some have turned the same suspicious eye toward our own fracturing processes. The 5.9 magnitude quake that hit on November 5th was the largest in the state’s history, according to the Washington Post, and residents have been feeling tremors ever since. Fracturing is common in Oklahoma to say the least, and some call the state “a center of the fossil fuel extraction industry.”

But many still question the quakes being related to the some 185,000 drilling wells and hundreds of injection wells across the state. As noted in an AP Report, U.S. Geological Survey seismologist Paul Earle stated that, “You can have an earthquake that size anywhere east of the Rockies. You don’t need a huge fault to produce an earthquake that big. It’s uncommon, but not unexpected.”

Until further evidence is produced, either by the government or the companies themselves, it’s remains likely that the earthquake was a natural occurrence unrelated to any particular well or company. Fracking may cause earthquakes of smaller magnitudes, as seen in England, but anything larger may be the work of the planet’s own forces.

As put by Stanford University geophysicist Mark Zoback in the same AP report, the energy released by fracking ”is the equivalent to a gallon of milk falling off the kitchen counter.”