Has fracking rid California of its earthquake crown?
February 9, 2015
Geologists recorded three times as many earthquakes in Oklahoma last year than in California, leading some scientists to finger fracking in Oklahoma as a cause or major factor. [Reveal]
In 2014, the U.S. Geological Survey reported 562 earthquakes of magnitude 3.0 or greater in Oklahoma and 180 in California. In addition to Oklahoma, states such as Kansas, Texas, Ohio and Colorado have seen increased seismic activity.
California has long been considered the earthquake hub of the U.S. mainland, but Oklahoma began catching up in 2009. Through one month of 2015, Oklahoma has far surpassed California in seismic activity.
The USGS recorded 76 earthquakes of magnitude 3.0 or greater in Oklahoma during January, compared to only 10 in California.
Last year, Oklahoma also passed Alaska, the nation’s perennial leader in total earthquakes. Many small quakes in remote areas of Alaska go unreported, though.
Numerous studies note an uptick in seismic activity in areas in which wastewater disposal from fracking, or hydraulic fracturing, is occurring and where faults already exist.
North Dakota is a leader in fracking and has not had a sizable increase in earthquakes. But, the state’s major shale oil deposits are not located near faults.
None of the recent Midwest quakes have resulted in deaths, though one in Oklahoma caused the roof of a house to collapse. A woman injured in the incident is suing two oil companies for allegedly triggering the earthquake, but the Oklahoma Geological Survey said in a 2013 statement that the 5.7 magnitude quake likely occurred due to a natural sequence.
The USGS is currently trying to update its earthquake hazard map to address how human behavior is impacting seismic activity.