Geologists placed additional seismic monitors on-loan from the United States Geological Survey in the Greenbrier area Monday in an attempt to more accurately monitor the region’s seismicity.

Scott Ausbrooks, a geohazards supervisor for the Arkansas Geological Survey, said the equipment was installed at the northwest corner of Greenbrier, just south of current activity.

Ausbrooks said more equipment is scheduled to be delivered today, and those monitors will be put in place tomorrow or Friday, just east of Greenbrier.

"You’ve seen how the location changes a little on the same event. That is because we’ve been down one station in Mountain View and one that we use at UALR to identify locations," Ausbrooks said. "These two stations will help us get more accurate locations and magnitudes."

The AGS works with several entities to monitor events in the area in an Arkansas Seismic Network. There are six permanent seismic stations placed in Arkansas state parks, one of which is located at Woolly Hollow State Park, east of Greenbrier.

Ausbrooks said the network is maintained by the Arkansas Geological Survey, the Center for Earthquake Research and Information at the University of Memphis and Arkansas State Park partners.

Equipment at Woolly Hollow State Park has recorded more than a dozen earthquake events in two days, with the highest register of 3.4 occurring two miles north of Greenbrier at 4:17 p.m. Monday.

Ausbrooks said the AGS has requested data from Arkansas locations from the past six weeks, and will continue to request activity reports each week in an attempt to find the relationship, if one exists, between area injection wells associated with the natural gas industry and increased seismicity. 

"We’re processing that data now to see if there’s a relationship between them," Ausbrooks said. "We’re continuing the study and we don’t know how it is going to come out yet."

According to Ausbrooks, the likelihood of an earthquake event of a magnitude greater than 5.5 on the Richter scale is small.

"There is a chance that we could see 5," Ausbrooks said. "If the whole fault were to rupture at once, we’d see a 5 to a 5.5. That’s unlikely, generally speaking, but it’s not out of the realm of possibility."

For more information on these stations and their recordings, visit www.geology.ar.gov.  

(Staff writer Courtney Spradlin can be reached by e-mail at courtney.spradlin@thecabin.net or by phone at 505-1236. To comment on this and other stories in the Log Cabin, log on to www.thecabin.net. Send us your news at www.thecabin.net/submit)