Wastewater Injection Blamed for Largest Human-Caused Earthquake Yet

By Breanna Draxler | March 27, 2013 1:36 pm

A 2011 magnitude 5.7 quake near Prague, Okla., apparently triggered by wastewater injection, buckled U.S. Highway 62. Image courtesy John Leeman via the Earth Institute at Columbia University.

Fracking has provided a growing domestic supply of natural gas in recent years. As a result, there has been a lot of talk lately about whether or not this method of fuel extraction produces earthquakes. Now research indicates that at least one part of the process—disposal of the wastewater from both fracking and conventional oil extraction—does indeed pose a real geological risk.

In the last four years, the number of earthquakes in the central United States has been 11 times greater than it had been over the three decades prior, according to geologists’ findings. Five of those quakes have been magnitudes of at least a 5.0. Researchers say this seismic activity is the result of injecting wastewater deep underground.

And according to a study published this week, wastewater injection was the cause of a magnitude 5.7 earthquake in Oklahoma in 2011—the largest earthquake to date thought to have been caused by human activities.

The wastewater in question comes from two fuel-extraction processes. Hydrofracking relies on a mix of water and chemicals to crack rock and release the natural gas it contains. Conventional oil extraction uses water to force oil reserves out of wells. Since the U.S. has ramped up its domestic fuel production, wastewater disposal has spiked as well. In the case of the Prague, Okla. earthquake, the wastewater was being pumped out of one set of oil wells and injected into another set that had already been drained of their oil.

This wastewater injection had been going on at the site for 17 years without incident before the nearby Wilzetta Fault finally gave way. The researchers suspect that the wastewater was slowly refilling the spaces once filled with oil, and succeeded in doing so for over a decade with little or no pressure buildup. But records from the wellhead indicate that injection pressure got 10 times greater between 2001 and 2006. This stress eventually forced the fault to jump.

The earthquake in Oklahoma was the largest the state has ever experienced, and was felt in at least 16 others. When it hit on Nov. 6, 2011, the series of major tremors injured two people, buckled a highway and destroyed 14 homes. The swarm of aftershocks numbered in the thousands, and continues to this day—as does the injection of wastewater near the site.

The Oklahoma Geological Survey says these aftershocks could still be natural, but the researchers say the likelihood of a big earthquake from human-caused pressure changes, even with relatively small amounts of water, is higher than they once thought. Plus, the risks are much greater now that they know the pressure can build during decades’ worth of injection before an earthquake finally strikes.

CATEGORIZED UNDER: Environment, top posts
  • JonFrum

    So was this due to fracking or not? Were they fracking 17 years ago?

    • Geowiz

      Oil producers have been fracturing the rock in the oil reservoirs for almost as long as they’ve been drilling. In the early days, they would drop nitroglycerin down the hole to cause explosions. Fracking by water injection has been standard practice since the ’40s. The only part that’s new is the drilling of horizontal wells and development of techniques to fracture a well that is sideways.
      When oil and gas are produced, varying amounts of salt water always comes up with it. In the old days, back in the ’20s, they used to dump the salt water on the ground or in streams causing a big environmental mess. In order to protect the environment, companies are required by law to dispose of wastewater safely – i.e. pump it back down deep in the earth from whence it came. Nothing new but the hysteria!

  • http://twitter.com/farscout1 Ryne Smith

    Considering that there is no solid evidence either way, it seems unscientific to blame this on the fracking at this time. One is entitled to one’s own opinion/hypotheses, but one is not entitled to one’s own facts.

  • Geowiz

    This article is intentionally inflamatory and one sided. Here is a link to a report by the Oklahoma Geological Survey concluding that the earthquake swarm was due to natural causes. http://www.ogs.ou.edu/earthquakes/OGS_PragueStatement201303.pdf

    For some more interesting reading, study up on the New Madrid, Missouri earthquakes about 100 years ago – a brief period of intense seismic activity in the mid-continent that produced the continent’s largest earthquake in recorded history. http://en.wikipedia.org/wiki/New_Madrid_earthquake
    Sometimes this stuff just happens!

    • http://www.facebook.com/fdelisa Fleur De Lisa

      The year 1811 was not 100 years ago but 202 years ago btw!

      • JonFrum

        Factually correct, but on a geological timescale, not even the blink of an eye.

        • linda518

          If you think Kenneth`s story is exceptional…, last pay check my auntie’s best friend basically made the small fortune of $6183 grafting a thirteen hour week at home and they’re best friend’s step-mother`s neighbour has been doing this for seven months and made more than $6183 part-time from their mac. use the advice at this website… jump15.comCHECK IT OUT

  • http://www.facebook.com/debbie.palomino.3 Debbie Palomino

    there was a time when simple folk with simple common sense would have found this completely unacceptable. There would have been riots by the angry, and panic and chaos amongst the frightened, but strangely, only a handful.of us are alarmed and concerned, we are being stifled by the herd mentality of the dumbed down sheeple, who do not want to know, their own wool over their own eyes. Sad.

  • http://www.facebook.com/debbie.palomino.3 Debbie Palomino

    as they tried to build a ladder to heaven, not to escape, but to possess what they felt entitled to, are they now digging their way to hell.


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