2 earthquakes hit Johnson County
JOHNSON COUNTY — Two earthquakes hit Johnson County Wednesday afternoon near Mansfield.
Preliminary reports rate the quakes as 3.0 and 3.2 magnitude. There have been no reports of damage or injuries.
This is bigger than a normal fracking quake, said CBS News Texas meteorologist Jeff Ray. Fracking is the extraction of natural gas or oil from shale and other forms of "tight" rock.
In 2015, a 4.0 magnitude earthquake near Johnson County, one of the largest to ever hit Texas, which renewed the fracking debate. At the time, four well operators agreed to shut down their wells temporarily until the results of the tests returned. The testing would determine the effect of wastewater injection into subsurface rock formations in the areas feeling the recent activity.
The Texas Railroad Commission found "no conclusive evidence" that wells were a factor in the 2015 quake.
SMU has been monitoring earthquakes in the area for many years. A study published in 2019 by the University of Texas and co-authored by SMU Associate Professor Heather DeShon linked seismic activity in West Texas with increased oil and gas development.
The paper begins, "Since 2008, there has been a significant increase in the number of earthquakes reported in the central United States (Ellsworth, 2013). This increase is generally attributed to wastewater disposal or enhanced oil recovery operations that produce changes to subsurface pressure and reduce friction that inhibits slip along existing faults."
The study also said that the earthquakes occurring in North Texas were within a few kilometers of high-volume wells, "suggesting that injected fluids caused pressure changes that diffuse away from wells and reach suitably oriented stressed faults."
This earthquake activity all but died out in this area once SMU started monitoring them, Ray said.
