Scientists have linked wastewater disposal from oil and gas activity to earthquakes in California for the first time. As Amy Quinton reports from Sacramento, the new study looked at earthquake activity in the southern Central Valley.
The study, published in the journal Geophysical Research Letters, examined an area in the southern San Joaquin Valley along the White Wolf Fault. It found increased injections of oil wastewater in the area in 2005 were followed five months later by a swarm of earthquakes that topped out at a magnitude 4.6. Seismologist and lead author Thomas Goebel, with UC Santa Cruz, says there is only a three percent possibility that such activity could be observed by chance.
Goebel: “It’s been known for a long time that induced pressure changes can reduce the effective stress on faults that may cause slip and earthquakes, but this is the first study in California that sort of shows a statistical correlation between injection and earthquakes.”
Oklahoma and some other Midwestern states have experienced hundreds of quakes linked to oil wastewater injection. But Goebel says the geology is very different in California and he wouldn't expect a similar scenario here.