Why Oklahoma Suddenly Has More Earthquakes Than California

The latest report on the recent earthquake epidemic in Oklahoma is out, and it's horrifying. Not only has the state seen twice as many earthquakes as California this year, but the scientific evidence that the seismic activity is linked to oil and natural gas production has become overwhelming.

It's not a secret that Oklahoma's become the earthquake capital of America. Since oil and natural gas drilling started became more common there about two decades ago, seismic activity has increased exponentially. The drilling itself isn't so much to blame, geologists say, as the practice of injecting wastewater into the ground, some of which is a byproduct of fracking. As i09 pointed out today, that does not mean that the earthquakes have been caused by fracking, though. I'll come back to that in a second.

This year, however, it looks like Oklahoma's earthquake problem has hit its tipping point. The earthquakes becoming more frequent and more extreme. And Oklahoma residents are scared.

The Problem

Oklahoma's seen a tremendous spike in earthquakes over the past few years. Oklahoma has also seen a large increase in wastewater injections. Fracking fluid is sometimes disposed of by pumping it into wells, but Oklahoma is using the practice for other purposes, like dewatering. Nevertheless, many scientists acknowledge that there is a strong correlation between wastewater injections and the increase in earthquakes.

Just last week, an expansive study was published in Science that detailed that correlation. The study links over 2,500 earthquakes in the past five years or so to "unconventional oil and gas production." Basically, the researchers believe that the ground has become so saturated with wastewater that it's become unstable, like a sponge that can't absorb any more water. In effect, the wastewater lubricates the faults, and they're now slipping more easily.

"Wastewater is using the same well for months and years, leading to an accumulative pressure," explains Katie Keranen, a Cornell geophysics professor and lead researcher of the study. "Because we have such high volumes (of wastewater) going in, the rocks are quite permeable, and the pressure is able to propagate to really far distances. If the fault is ready to fail, it doesn't take a lot of change in pressure to trigger an earthquake."

Why Oklahoma Suddenly Has More Earthquakes Than California

Correlation or Causation?

Despite the sound science, it's proved difficult to convince policymakers in Oklahoma that the state's booming oil and gas industry is responsible for the recent rash of earthquakes. The oil business is going really well there! Right now, one in six jobs in the state are associated with the oil and natural gas industry, and Oklahoma ranks number five in the nation in terms of oil and gas production. That means that Oklahoma needs a lot of wastewater disposal wells—4,500 of them to be exact. In fact, 80 percent of the state is within nine miles of a wastewater injection well.

The oil and gas industry is obviously denying the link. "We've been doing injection in the state for a long time," Chad Warmington, president of the Mid-Continent Oil and Gas Association of Oklahoma, told Bloomberg recently. "It deserves a lot more investigation before making a determination." Duane Grubert of SandRidge Energy similarly said, "We don't want anyone to rush to judgment based on faulty or inaccurate data and that's all we're asking for."

And yet, this most recent Science study is one of many that links wastewater injection to a spike in seismic activity. Similar studies have been conducted in Arkansas, Texas, and Colorado, though none of those states are dealing with an earthquake problem like Oklahoma is. All that said, it's been difficult to get specific data about sub-surface pressure that would serve as a sort of smoking gun, so the oil executives kind of have a point. Even though the correlation probably means causation, "probably" isn't a word often used in sound science.

Why Oklahoma Suddenly Has More Earthquakes Than California

What's To Be Done

Something's gone very wrong in Oklahoma. The earthquakes aren't just becoming more frequent; they're becoming stronger. So far this year, Oklahoma's seen 238 quakes over magnitude 3.0, and just three years ago, a magnitude 5.7 earthquake in the town of Prague broke a 60-year-old record for the strongest modern earthquake in the state. The damage is stacking up, too. Chimneys are crumbling. Homes are cracking. People are getting hurt.

Something's gone wrong, and something needs to be done. In a joint statement in May, the state and federal geological surveys issued a joint statement that said the earthquakes "do not seem to be due to typical, random fluctuations in natural seismicity rates." Some suggest that one approach to dealing with the earthquake problem would be for the state to require seismic study before drilling. Others want the drilling to stop altogether.

What seems increasingly clear, however, is the simple fact that the oil and natural gas industry needs to own up to the problem. There are other ways to deal with wastewater. There have to be better, more sustainable ways of drilling. Because at the end of the day, when sucking up the Earth's natural resources is so disruptive that the ground starts to shake, it's worth admitting that our existing methods aren't working.

Images via AP