Pumping all manner of fluids into deep rock formations has triggered earthquakes strong enough to cause a bit of damage while seriously rattling the local populace, a committee of the National Research Council (NRC) concluded in a report released today.
Fracking for natural gas and oil, formally known as hydraulic fracturing, has been responsible for only one or two triggering episodes, the committee found. But hundreds of felt quakes in 13 states have been produced by the deep injection of wastewater from fracking and other industrial activities, as well as the creation of geothermal energy sites, the enhanced recovery of oil and gas, and even the simple extraction of oil and gas. And capturing the greenhouse gas carbon dioxide from power plants and pumping it into the ground "may have potential for inducing larger seismic events," the committee found, because much larger volumes would be involved.
The committee also concluded that drillers could better anticipate and ameliorate the seismic hazards of fluid injection. The basic science is well understood, it noted, but forecasting the hazard from induced earthquakes and taking steps to minimize the risk have been frustrated by the dearth of detailed geologic and geophysical observations of specific sites.
Assessments of the risk of induced seismicity "should be undertaken before operations begin in areas with a known history of felt seismicity," the committee wrote. Such pre-injection studies have generally not been done in the past, although some new state regulations are moving in that direction. And of course, "Further research is required."