Edmond, Oklahoma experienced a 4.3 magnitude quake December 29 amid a swarm of quakes the state experienced that day. Chimneys and contents of shelves purportedly tumbled to the ground, and 4,400 individuals lost electricity. The Oklahoma Corporation Commission continues to develop a response to the complex phenomenon, noting January 1 that “the initial review of the data for the area in question has not identified any oil and gas wastewater disposal wells that are both high volume and in the state’s deepest formation, a combination that researchers have identified as being at the highest risk for inducing earthquakes.”
The announcement comes a few weeks after the Oklahoma Corporation Commission announced in early December it would bring court action against an operator that refused to shut down a well impacted by the Commission’s December 3 induced seismicity directive. Although the Commission’s induced seismicity directives are voluntary, they carry the threat of legal action.
The recent quakes in Oklahoma have also revealed a previously unknown fault. Researchers are concerned that the fault may connect to the larger Nemaha Ridge fault responsible for the magnitude 5.6 Prague earthquake in 2011, the largest quake Oklahoma has experienced. That seismic event resulted in a lawsuit which a Lincoln County judge recently allowed to proceed despite a motion to dismiss on statute of limitations grounds. Measures to locate faults remain a focus of recent regulatory steps.
Induced seismicity is increasingly a focus of authorities abroad as well. In December Canadian regulators claimed that a 4.6 magnitude quake in northeast British Columbia this summer “was caused by fluid injection during hydraulic fracturing from an operator in the area.” That earthquake in the Horn River Basin was the largest seismic event attributed to hydraulic fracturing globally up to that point.
Reports of a 4.8 magnitude quake on December 29 in Vancouver, British Columbia resulted in temporary suspension of mass transit rail. No evidence reveals a link to wastewater disposal activity or hydraulic fracturing.