Earthquake Activity in the Azle/Reno Area: Southern Methodist University Announces Major Study
North Texans know a lot about tornadoes and golf ball-size hail storms, but when it comes to earthquakes, many Texans are experiencing them for the first time. Our first instinct is to ask what is causing them and what we need to do to stop them.
Starting in late 2013, the Reno-Azle region in North Texas experienced numerous earthquakes, most were too small to be felt but some were stronger. Since earthquake activity in this area in North Texas has not been experienced before, the scientific community has taken notice.
On February 7, 2014, Southern Methodist University announced that they had embarked on a major study of the earthquake activity in the Reno-Azle area, and have installed seismic equipment in that area. The seismographs have been placed around the epicenters of the activity and will remain there for up to a year or longer.
This is a welcome announcement; everyone wants scientifically sound answers, including the oil and gas industry.
SMU said that they have deployed several different types of earthquake monitors in the Reno-Azle region:
“We first deployed five NetQuakes stations provided by the United States Geological Survey in the area identified as the epicenter for the quakes that occurred through January 2014. These small instruments are designed to be installed in private homes, businesses, public buildings and schools. Other monitors are being deployed throughout the region. We have deployed seven continuous recording, higher performance seismic sensors to date.”
The geophysics professor leading the research team, Heather DeShon, said in a press conference:
“It is important we do not rush to conclusions … I understand people want results quickly. But we have to sit and wait a little while.”
The SMU website emphasized that the process of collecting data and analyzing it is not a quick and easy exercise:
“Finding the answers is complicated by the relationship of geology (such as the location of faults) to oil and gas production (extraction), or to wastewater disposal (injection), and even our growing ability to sense and locate earthquakes. It will take collaboration and shared data between scientists, industry and government to provide better information on the causes of induced seismicity.”
As for timing, the SMU website says:
“We will continue to monitor the earthquake sequence over the next six months to a year, unless activity remains high. We have not determined a timeline for completing additional studies. We do not consider our seismic studies complete until results have been published in peer-reviewed literature, which is the traditional, academic process that provides for thorough review of research methods and conclusions by qualified peers from within that scientific discipline. Past studies of seismicity in the Dallas-Fort Worth area have taken one to two years.”
In response to the question “Can the Reno-Azle research determine if the earthquakes in that area are connected to wastewater injection wells operating nearby?” SMU responded as follows:
“Understanding if and/or how wastewater injection wells contribute to seismicity requires not only improved earthquake locations, but also high-resolution well log data and subsurface information about rock type, permeability, porosity and fault structures. Much of this data is collected by oil and gas companies as part of exploration and pre-drilling site verification, and ultimately it will take the cooperation and data sharing between the private and public sectors to make progress on this important science topic. We cannot say at this time if we will be able to definitively, and in a scientifically verifiable way, show if the Reno-Azle sequence are induced or natural earthquakes.”
In addition to the SMU study, the University of Texas Jackson School of Geosciences has a similar study underway, and the Railroad Commission of Texas announced that they are working with SMU and also hiring a seismologist.
It is good news that the scientific community and the state regulatory agency have focused on the earthquake activity in the Reno-Azle area in North Texas. While we all wish their findings would come sooner rather than later, it will take time for sound scientific conclusions to be reached.