A 2005 spate of quakes in California’s Central Valley almost certainly was triggered by oilfield injection underground, a study published Thursday said in the first such link in California between oil and gas operations and earthquakes.
Researchers at the University of California at Santa Cruz, the University of Southern California and two French universities published their findings Thursday in a publication of the American Geophysical Union. The research links a local surge in injection by oil companies of wastewater underground, peaking in 2005, with an unusual jump in seismic activity in and around the Tejon Oilfield in southern Kern County.
In Oklahoma and other Midwestern states, the U.S. Geological Survey and others have linked oilfield operations with a dramatic surge in earthquakes. Many of those quakes occur in swarms in places where oil companies pump briny wastewater left over from oil and gas production deep underground.