There is a likely link between a series of small earthquakes at Dallas-Fort Worth International Airport and a Chesapeake Energy Corp. injection well used to get rid of wastewater from natural gas drilling, according to a new study analyzing the events.

Researcher Brian Stump of Southern Methodist University, one of four researchers who worked on a study published in the magazine Leading Edge, said the injection well at the airport was a "plausible cause" of the earthquakes that started seven weeks after the well began operating in 2008 and stopped when the well was closed.

Chesapeake Energy disputed that conclusion.

"Our study sees no relation to the drilling, no relationship to the hydro-fracking," Stump said. The research suggests that the pressure from fluid, or possibly heat from the process, could have been a trigger for the earthquakes, he said. Stump added that the fluid could have also served as a lubricant and caused the existing fault line to slip.

Chesapeake, however, "maintains that a direct, causal relationship between saltwater disposal wells and seismic activity in the DFW area has not been scientifically proven," spokesman Brian Murnahan wrote in a statement. He declined to elaborate.

The earthquakes were not big enough to do any damage on the surface -- the biggest was magnitude 3.3.

The research team discovered that the earthquakes were centered on a fault line that ran close to the injection well at the south end of the airport, Stump said. Also, they occurred at the same depth as the injection well.

The researchers could not draw a conclusion about earthquakes that were felt in Cleburne around the same time, and research there is ongoing. "We need, more broadly, an understanding of these kinds of events," Stump said.

"If the D-FW earthquakes were caused by saltwater injection or other activities associated with producing gas, it is puzzling why there are only one or two areas of felt seismicity," Stump said in a news release (Mike Lee, Fort Worth Star-Telegram, March 10). -- DFM