Policy Response to Manmade Quakes Must Bridge Gap Between ‘Likely and Certainly’
Oklahoma’s November 2011 earthquake was “likely triggered” by drilling fluid injection in nearby disposal wells, according to research by University of Oklahoma seismologist Katie Keranen.
The 5.6-magnitude temblor near Prague was Oklahoma’s largest on record and the largest quake associated with underground injection. And while there’s growing scientific evidence that disposal wells and hydraulic fracturing can trigger earthquakes, proving definitive cause-and-effect is difficult — if not impossible.
Oklahoma’s drilling regulator, the Corporation Commission, is keeping an open mind, the Tulsa World’s Wayne Green reports. But it’s hard to act on “an open question”:
The commission has turned to the state geological survey to investigate the issue, but until it comes up with conclusions, the issue is unresolved, he said.
Keranen presented the findings Wednesday during the American Geophysical Union’s fall meeting in San Francisco.
Austin Holland, research seismologist for the Oklahoma Geological Survey, is hopeful scientists will be able to explain the cause of the November 2011 earthquake, but tells the World that definitive data may never be available.
Holland urges a healthy scientific skepticism:
Holland said falsely identifying a natural earthquake as something man-made would have reverberations beyond the scientific community. An induced earthquake would not be included in U.S. Geological Survey’s hazard calculations, which are used to create and update building codes and establish construction requirements.