No, the title was not a typo. And perhaps even more strangely, they’ve got a point, but there may be just a bit of an overreaction here. Areas with large amounts of high volume hydraulic fracturing (fracking) taking place have experienced low grade earthquakes in several areas around the country. When I first heard of these stories several years ago I was, I admit, more than a little incredulous. But the science done in the oil and gas industry has built up sufficiently to show that small earthquakes can indeed be triggered by human activity. Oklahoma is concerned about this and asking for voluntary action on the part of energy companies to tamp things down. (Washington Times)
The state commission that regulates Oklahoma’s oil and natural gas industry ordered some injection well operators to reduce wastewater disposal volumes on Monday after at least a dozen earthquakes hit an area north of Oklahoma City in less than a week.
The Oklahoma Corporation Commission said it was implementing a plan that affects five wastewater injection wells operating within 10 miles of the center of earthquake activity near Edmond, a northeast suburb of Oklahoma City. Among the recent quakes to hit the area was a 4.2 magnitude temblor on New Year’s Day that caused minor damage but no injuries.
“We are working with researchers on the entire area of the state involved in the latest seismic activity to plot out where we should go from here,” Oil and Gas Conservation Division Director Tim Baker said, adding that responding to the swarm of earthquakes in the region was an ongoing process.
You can read a brief summary of one of the two types of fracking related earthquakes here and it’s fairly straightforward even for the layman. There can be direct or indirect quakes caused when there’s a sufficient amount of activity. Some of the earliest ones we heard about were in the Midwest, especially in places where there typically isn’t much tectonic activity. If you disrupt and/or remove enough material from a mile or two below the surface, the weight of the crust over that area can and sometimes will shift under the force of gravity as gaps are filled in. That can produce a (generally very small) earthquake with little effect on the people living above.
The second type, as described in the link above, is a more indirect effect. As fracking operations proceed there is a need to dispose of the water used in the compression process. The easiest, safest and most environmentally friendly way to handle this is to drill disposal wells deep below the ground, fill them with the used water and seal them with concrete. Unfortunately, as is the case in Oklahoma, you may be injecting a lot of water into an area which already has naturally occurring fault lines. The water acts as a lubricant and as it build up it can allow the boundaries to slip sooner than they might have naturally and perhaps a bit more suddenly, resulting in a quake.
These are still quite minor in size with the largest one recorded still being barely over a 4.0, but it’s enough to alarm people and potentially cause some minor damage. While I’m all on the side of the energy industry, I think they’re on the right side of the question here by voluntarily spreading out the injection sites and reducing the potential impact of these effects. One part of being successful in the energy industry is maintaining good relations with the public – particularly the ones you may need to lease land from – and this is a small price to pay for some good will and to cut down the shaking.