“But as long as they continue current operations, we don’t expect induced seismicity in L.A.” “If you start doing stuff like in Oklahoma … then, yeah, it’s a different ballgame,” Hauksson said. And there’s no obvious connection between quakes and the 72 oil fields in the Los Angeles Basin. But studies show that out of 1,400 disposal wells in the southern San Joaquin Valley, earthquakes were possibly related to activities at only four of them.

In Oklahoma, the wastewater is disposed of outside the oil fields and injected below the groundwater aquifer, where it can trickle down and trigger movement on a long-dormant fault, Hauksson said.įracking has been conducted in the last few years in Southern California, including at the Inglewood and La Brea oil fields, Hauksson said, and wastewater has been injected back into the ground. But in Oklahoma, workers need to break up dense shale rock to get the oil out of it, Hauksson said, which results in more toxic wastewater.Īnother difference: In Southern California, wastewater is generally injected back into watertight traps where the oil came from. One factor is that the Los Angeles Basin’s petroleum deposits are thick with oil. In California, scientists say different oil extraction practices may be why earthquakes aren’t occurring due to wastewater injection here. Ideas include improved seismic sensors in the ground so scientists can detect smaller earthquakes. Scientists say they believe more research can help officials better manage the risk. Many experts concluded that the fluid injections were responsible, according to a study at the time in the journal Science. In the 1960s, a geophysical observatory operated by the Colorado School of Mines detected more than 1,000 small quakes in an area near the Rocky Mountain Arsenal, where chemical-waste fluid was deposited into a 12,000-foot well. The idea that forcing water deep into the ground can trigger earthquakes has been discussed for decades. “We know, for example, in Oklahoma that there was an earthquake of about magnitude 7 about 1,300 years ago,” Ellsworth said. History suggests the area could produce a devastating quake. The seismicity rate in 2013 was 70 times greater than the background seismicity rate observed in Oklahoma prior to 2008, state officials said. This week, the Oklahoma Geological Survey acknowledged that the state’s sharp rise in quakes is “very unlikely to represent a naturally occurring process,” since the quakes are occurring over the same area that saw a huge jump in wastewater disposal in the last several years. Parts of Texas, Kansas, New Mexico and Ohio all have experienced more frequent quakes in the last year.īut Oklahoma leads the pack.

USGS scientists concluded the rupture began very close to some of the largest wastewater injection wells in the basin. The basin saw a huge increase in the number of earthquakes beginning in 2001 after oil extraction jumped two years earlier.īy 2011, one of the region’s largest earthquakes was recorded - a magnitude-5.3 earthquake near Trinidad, Colo. One of them was the Raton Basin in southern Colorado and northern New Mexico. The areas highlighted on the map “are all located near deep fluid injection wells or other industrial activities capable of inducing earthquakes,” the report said. The study maps 50 years of earthquake activity in 17 “induced seismicity zones” scattered across eight states.

Similarly, there is no evidence of induced earthquakes in North Dakota, where part of the Bakken Shale is located, “despite very large volumes of fluid that are being disposed of,” said USGS geophysicist William Ellsworth, who worked on the new report.

Oklahoma quake map 2015