Earthquakes continue for years after gas field wastewater injection stops, study finds: High rates of injection and large volumes can perturb critically stressed faults, triggering earthquakes years after wastewater wells are shut in
https://www.sciencedaily.com/releases/2018/02/180213145820.htm
Shutting down oil and gas wastewater injection wells may not stop human-induced earthquakes quickly, say seismologists. The scientists analyzed earthquakes at DFW Airport that began in 2008 and found that even though wastewater injection was halted after a year, earthquakes continued for at least seven more years. They concluded that high-volume injection, even for a short time, can induce long-lasting seismicity when it’s near a critically stressed fault.