Arkansas Earthquakes May Be Linked to Drilling

MEMPHIS, Ark. - Dozens of earthquakes in central Arkansas have gained national attention and Friday they were still being felt. FOX13's Scott Madaus spoke with an earthquake expert at the University of Memphis to get and answers about what is causing them.

Since October of 2010 there have been more than 750 earthquakes in Faulkner County, Arkansas. Local experts say what they think might be causing the quakes. Deep inside the Center for Earthquake Research and Information at the University of Memphis Dr. Steve Horton said for his field of interest the last few days have been exciting.

“It has been interesting.”

Dr. Horton said dozens of earthquakes have been documented north of Little Rock in 24 hours.

“36 maybe even 50 that have been large enough that we located them,” said Dr. Horton.

Then early Friday morning the biggest in this cycle, a 4.1 quake.

Researchers say it could be naturally occurring swarms that have been documented in the area since the 80's or it might be the result of ongoing gas exploration.

“They actually started the activity after the injection wells started injecting,” said Dr. Horton.

In layman terms, drillers use heavy equipment to tap into natural gas by using pressurized water to create fractures where the gas is beneath the surface.
After that process the waste is then shot into the ground and that's what researchers think may be causing the quakes.

“They started doing these injection wells in the area that were talking about in April of 2009- since that time there has been an increase in the rate of seismicity.”

The earthquakes could still be felt as late as Friday afternoon. So now researchers with the University of Memphis will continue to look at the quake swarms and analyze data as it relates to injection well use.

“We’re still studying it so it turns out it's very difficult to prove a cause relationship,” said Dr. Horton.

If you'd like to follow the central Arkansas earthquakes, click on the link attached to this story.