During the early morning of Sunday, Oct 10, a 4.5 magnitude earthquake shook a great portion of north-central Oklahoma. Those who were woken by the tremor flooded social media with concerned posts around 4:30 a.m. The epicenter was near Cushing, Oklahoma, a major crude oil trading hub, where 85 million barrels of oil are stored on average and through which much of the nation’s oil is transported by pipeline.
Ten years ago, the number of Oklahoma earthquakes fluctuated within the single digits. An exponential increase began in 2009, and despite several dip years, the numbers remain on the rise. To give an idea of scale, there were 584 earthquakes above 3.0 magnitudes last year alone. That’s five times the figures in 2013 and 582 more than the two recorded in 2004.
According to the USGS’s 24 hour seismicity report in Oklahoma, as of 6:45 p.m. Oct 12, six tremors ranging from 2.7 to 3.3 dotted the map west of Osage County. Generally, an earthquake above a 3.0 magnitude is considered significant and can be felt at the right location.
The 4.5 on Sunday is not uncommon in present-day Oklahoma, but is still significant enough to make national news. Do these epicenters and numbers map a predictable pattern caused by man, or is Oklahoma experiencing the natural patterns of geological change?
The significance of this particular earthquake is steeped in an ongoing controversy over the effects of oil production on the fault lines beneath Oklahoma.
Many claim that hydraulic fracturing—the high-pressured injection of more than a million gallons of water, sand and chemicals to crack the rock underground—directly correlates to the rise in frequency of Oklahoma earthquakes.
Many in the petroleum industry profess there is no correlation, while the opposition has no scientific evidence to connect fracking with earthquakes (reports are speculation at best). This fact is problematic; while Oklahoma does not regularly experience the kinds of earthquakes that shake the West Coast, legislatures, scientists and businessmen should make the proper inquiries to determine what can be done.
Oklahoma’s economy depends on petroleum. If petroleum production results in natural disasters, should the state be responsible for taking the required measures to prevent further damage?
This is a situation where compromises are currently made without fully understanding the issue. Research needs to be done to determine a course of action in which checks and balances are in place to protect both Oklahoma’s economy and environment.
Many use fracking to rally against the petroleum industry when in fact, public opinion and media attention are largely focused on the wrong issue. A different oilfield practice might be what relates oil production to earthquakes. The use of deep wastewater injection wells is more likely to cause earthquakes, if at all, so these territories are marked by speculation.
Injection wells are used for the disposal of oil production’s hazardous byproducts. For every barrel of oil pumped up from the ground, twenty barrels of naturally occurring brine come with it on average. The oil-laden fluid has to be disposed of, so it is forced at high pressures into disposal wells. Used fracking fluid is disposed of in the same way, and is injected in volumes of millions of gallons. The current theory is that this fluid might be seeping into fault lines and triggering earthquakes.
The Oklahoma Corporation Commission is responsible for regulating Oklahoma’s oil and gas practices. On September 18, 2015, as a direct result of the seismic activity in the Cushing area, the OCC implemented a plan. The plan called for two injection wells to cease operation and for three others to reduce disposal volume.
“As a result of an analysis of disposal well and seismicity data in the Cushing area,” the OCC advisory reads. “The Oklahoma Corporation Commission’s Oil and Gas Conservation Division (OGCD) is implementing a plan to change the operation of certain disposal wells in the Cushing area. The plan may be altered as more data is made available.”
The 4.5 near Cushing occurred within the boundaries regulated by the report. If the disposal of wastewater and fracking fluid does affect Oklahoma’s faultlines, no one knows what irreversible damages might already be done.
From Jan 1 – May 27, 2015, there were 381 earthquakes in Oklahoma. The USGS projects that approximately 941 earthquakes will strike Oklahoma over the course of this year.
Scientists and geologists are scrambling to uncover the truth behind oil production and earthquake relations while oil and gas companies are addressing the matter with good PR and public debate.
Many Oklahoma lawmakers and activists are combatant against those companies in hopes of saving the state from a disastrous earthquake.
Oklahomans are stuck in the middle, going about their day and occasionally stopping as the ground rumbles beneath their feet.