Frequent and intensified earthquake activity in West Texas over the last several months may be linked to fracking-related activity, APA reports citing Sputnik.
West Texas, the top region in the state for oil and gas production, experienced a 5.4 magnitude earthquake that hit on November 16 and a 5.4 magnitude earthquake that occurred in the same region on December 16, marking the most intense seismic activity to strike the area in about three decades, according to the US Geological Survey.
"Most of the earthquakes in West Texas are considered induced earthquakes, which are mainly caused by wastewater injection-a process for oil and gas production," University of Houston Geophysics Professor Aibing Li told Sputnik.
"Long-term wastewater injection results in a pore pressure increase in crustal rocks, the chief reason to weaken faults and cause earthquakes. Some studies link some earthquakes to fracking activity in West Texas because the process also involves liquid injection and pore pressure increase."
Li said she is not surprised by the latest seismic activity since increasing earthquake activity has been going on in West Texas for a decade, however, the increase in large-size earthquakes above magnitude 5.0 is certainly a concern for earthquake hazards.
Although earthquake activity is hard to predict, Li predicts seismic activity in West Texas will continue for some time until built-up stress and pore pressure induced by long-term wastewater injection is released enough by earthquakes. However, according to Li, earthquakes have cycles and they will come back if pore pressure is built up again by wastewater injection and fracking.