Scientist finds injection wells may cause earthquakes

LINCOLN COUNTY, Okla. - After a 5.6 quake rocked Lincoln County and damaged homes many wondered what was behind the quake.

In February we examined whether the state's injection wells could've caused the quakes. Here's how it works: Once a rock is fracked, water is used to get the oil and gas out, that water/fluid is then disposed of in an injection well that's often a mile or more deep in the ground.

There are nearly 200 injection wells in Lincoln County alone, leaving some scientists to wonder if they were causing the quakes. Austin Holland, with the Oklahoma Geological Survey, is the state's expert.

"I would certainly say that it's possible and we're looking into it, but at the moment the data is just very inconclusive and really doesn't suggest that, for instance, injection has continued since the earthquakes happened and the earthquakes have decreased dramatically sort of as we'd expect in a natural process," Holland said.

But not everyone agrees with that.

2NEWS sent Steven Horton, a seismologist for the Center of Earthquake Research and Information out of Memphis, reports from 2010 on how much fluid was injected into the five wells functioning close to the epicenter in Lincoln County.

Horton said based on "the proximity of the wells to the earthquake and the previous seismic activity in the source area, the M5.6 earthquake was possibly triggered by fluid injection wells."

Horton presented his findings to fellow scientists at a conference in San Diego on Wednesday. It's a story we will continue to follow.