By CHRISTIN COYNE and JUDY SHERIDAN
PARKER COUNTY – Two earthquakes shook northeast Parker County early Saturday and Monday mornings, bringing the total number of earthquakes this month in the Azle area to 14.
A 2.9 magnitude earthquake south of Reno rattled the area around 3:45 a.m. Saturday, followed by a 3.3 magnitude quake several miles west of Azle around 1:45 a.m. Monday.
The recent spate of earthquakes in the area began on Nov. 5 and included a 3.6 magnitude shaking on Nov. 19.
Scientists say they aren’t sure what’s causing the swarm of earthquakes, though some believe oil and gas disposal wells may be contributing.
Cliff Frohlich, associate director and senior research scientist at the University of Texas Institute for Geophysics, recently studied seismographic data collected on the Barnett Shale from 2009-11 and hypothesized that earthquakes might be related to injection wells if certain conditions are met, specifically a nearby fault that is already under stress.
Parker County Commissioners voted Monday to have County Judge Mark Riley send a letter to the Texas Railroad Commission asking them to investigate any connection between the earthquakes and Parker County’s injection wells.
Parker County Fire Marshal Shawn Scott said the quakes were short in duration — a second or less to a second-and-a-half — and shallow in depth. In some cases they caused windows to rattle, he said, but there have been no reports of damages or injuries.
“If you remember a few years ago, when we felt the ground shaking, I think it was a 5.6 that shook Oklahoma City, that’s what we felt. So in the grand scheme of earthquakes, these have all been very minor.”
He reported “a lot of calls in the dispatch center.”
“I’ve had numerous calls,” Precinct No. 1 Commissioner George Conley said, “people concerned about the earthquakes and what we are going to do about it.”