USGS maps fracking-related earthquakes
New maps released by the U.S. Geological Survey reveal that 7 million people are now living in areas at high risk for earthquakes. Not naturally occurring earthquakes but man-made – induced by oil and gas operations that pump wastewater deep underneath the ground.
Parts of Oklahoma and Texas are at highest risk, but the map also shows areas of risk in Colorado, primarily in the Raton Basin along the New Mexico border, but also in western Colorado around Rangely and Paradox Valley. A 3.2 magnitude “induced” earthquake occurred in the Greeley area in June 2014.
Last year Oklahoma had more than 900 quakes, up from three in 2007. There were several 4.0 magnitude quakes around Cushing, Oklahoma, in late 2015, during which buildings were damaged. But homeowners have few options when they try to recoup damages from insurance companies or the oil and gas industry.
Out of about 100 claims filed for earthquake damage in Oklahoma in 2014, only eight were paid, according to the Oklahoma Insurance Commissioner.
In Colorado, a bill has passed the state House that would make it easier for homeowners to sue oil and gas companies for property damage related to induced earthquakes. The industry strongly opposes the legislation. In Oklahoma, there is similar pushback from oil and gas against laws or regulations that would restrict operations.
Meanwhile, the new USGS map shows areas of seismic activity in Oklahoma as active as naturally occurring earthquake regions of California.
According to the USGS, studies suggest that the actual hydraulic fracturing process is only very rarely the direct cause of earthquakes strong enough to be felt. While hydraulic fracturing works by making thousands of extremely small “microearthquakes,” they are, with just a few exceptions, too small to be felt, with none causing structural damage.
The larger induced earthquakes have been linked with the underground disposal of wastewater co-produced with oil and gas in fracking operations.
The report notes that “the current regulatory framework for wastewater disposal wells was designed to protect drinking water sources from contamination and does not address earthquake safety.”
The largest earthquake induced by fluid injection that has been documented in the scientific literature was the November 6, 2011, earthquake in central Oklahoma. It had a magnitude of 5.6. Earlier that year, a magnitude 5.3 earthquake was induced by fluid injection in the Raton Basin, Colorado.
Earthquakes with magnitudes between 4.5 and 5.0 have been induced by fluid injection in Colorado, Arkansas, Kansas, Oklahoma and Texas.