Oklahoma surpasses California in earthquakes; scientists point to injection wells as likely cause

Oklahoma has far surpassed California in number of earthquakes, and state and federal scientists say "deep injection of wastewater from oil and gas production is a 'likely contributing factor'," Mike Soraghan reports for EnergyWire. Since October, Oklahoma has had 189 earthquakes of magnitude 3.0 or higher, compared to 139 in California; in 2014 the Sooner State has had 147 such quakes, compared to 70 in the Golden State. From 1978 to 2008, before the recent oil and gas boom hit Oklahoma, the state only averaged two earthquakes per year. (EnergyWire graphic) 

The U.S. Geological Survey and the Oklahoma Geological Survey "have linked much of the increase in Oklahoma to deep injection of waste fluid from oil and gas production in the drilling-heavy state," Soraghan writes. The agencies issued a warning Monday "that the risk of a damaging magnitude-5.5 or larger quake has gone up 'significantly'."

A study by the USGS, Cornell University and Columbia University blames injection wells for the increase in quakes. Last week Cornell geophysicist Katie Keranen said at the annual meeting of the Seismological Society of America that a cluster of four high-volume wastewater injection wells in Oklahoma City "triggered quakes up to 30 miles" away and have since "spread farther outward, as fluids migrate farther from the massive injection wells."

"Seismologists have also linked earthquakes in Arkansas, Colorado, Ohio and Texas to injection of wastewater from oil and gas production," Soraghan writes. (Read more)