According to a study published in the July 4th issue of the magazine called Science, the state of Oklahoma has experienced a 22,900% increase in the number of earthquakes registering 3.0 or greater on the Richter scale. The state normally experiences seismic activity of only one quake per year that meets or exceeds 3.0.
However, with only half the year finished, the state has already experienced 230 such quakes. The increase is as alarming as it is disturbing. It is believed that fracking and waste water injection are responsible for the increased seismic activity.
Hydrofracking is the fracturing of rock layers using highly pressurized liquid. It is now commonly being used to drill for coal steam gas, shale gas, tight gas, and tight oil. Waste water injection is a specially created well into which waste water is deposited back into the earth. According to researchers from Cornell University, not all waste water injection sites are causing increased seismic activity. They have found that a select group of them and it may have to do with how the composition of the waste water is interacting with certain rock formations. Regardless, it is entirely possible that these handful of injection sites are causing state-wide earthquakes.
Another factor increasing seismic activity is the amount of water being injected into the earth. Excessive amounts may creating what is termed “overpressure” for the underlying fault system resulting in otherwise stable tectonic areas to slip IE quake. Obviously, if the research is correct, hyrdrofracking and wastewater injection will need increased regulation and oversight to reduce man-made earthquakes.