The earthquakes continue to rumble under the town of Guy, Ark. The same place reported to be shaking a few months ago hasn’t slowed down. In fact, a report in the New York Times suggests that the town’s 563 residents are “getting comfortable” with the thousands of small earthquakes that have been taking place there since last fall.
The quakes are generally small and though thousands have been recorded, most aren’t actually felt. What has become known as the “Guy earthquake swarm” is one weird story.
First of all, Guy has a history of shaking. The town sits in relative proximity to the intersection of a few tectonic plates and dating back to the 1870s has had several “swarm periods,” include one quake measuring above 7.0 magnitude on the old-school Richter Scale. Beyond the town’s shaky history (sorry) there are also questions about whether energy production, specifically hydraulic fracturing or fracking as it is known, is causing the latest swarm.
In Guy and the surrounding area, there has been an increase in fracking, which involves injecting hazardous chemical mixtures underground to get to natural gas sources. When the gas is released, something has to be done with all that salty-chemical-water mixture. The answer to this drilling problem has been more drilling. So around Guy, there are many disposal wells that are about 12,000 feet deep.
Similar wells in Derby, Colo., caused several quakes in the 1960s. There was another investigation about the same thing happening in Trinidad, Colo., about 10 years ago. A similar situation is suspected of being the cause of quakes in north Texas where disposal wells were drilled near fault lines.
“We haven't ruled out a connection to the salt-water disposal wells," said Scott Ausbrooks of the Arkansas Geological survey a few months back. Fast forward to the New York Times' story from this weekend, and Ausbrooks seemed to come closer to drawing a direct connection between well-drilling and Guy’s situation. “All this activity happened after these wells had gone online,” he said.
Of course the exact cause of all this is anyone’s guess. There is some serious seismic history in Guy, but there’s also a history of well-drilling agitating an already active seismic area. As we ponder the cause of the quakes, it'll be interesting to keep an eye on Guy.