Oil and Gas Drilling May Have Caused Texas Earthquakes

A recent study by researchers and scientists from the University of Texas, Austin shows that a group of earthquakes in Eagle Ford, South Texas is likely to be caused by oil and gas drilling, says State Impact.

According to Bloomberg, the study will be released in the online edition of the Earth and Planetary Science Letters journal this week. The report made use of small magnitude quakes between November 2009 and September 2011.

In the study, it was found out that the cluster of seismic events were "often associated with fluid extraction." In fact, 47 out of the 62 quakes during the study period were most likely caused by extracting huge volumes of oil and fluids like water from the ground.

"There's famous stories in mining, where people mine in an area and then things collapse, and the collapse is just a little earthquake. So if you're removing fluids, it's changing the stresses locally. It's also changing the stresses on faults. So either removing or adding fluids can cause earthquakes," says Cliff Frohlich, Associate Director at UT's Institute for Geophysics and lead author of the study in a report by State Impact.

Although there were quite a few earthquakes in Southern Texas in the past years, the said earthquakes were reportedly small and did not cause considerable damage to properties. The quakes also did not injure any individual.

However, more recent earthquakes like the 4.8 seismic event included in the study which occurred in Fashing are getting large enough to be a concern, says Frohlich.

The earthquake was felt throughout the San Antonio area, and as far south as Kingsville and as far north as Burnet on October 20, 2011, says San Antonio News Express.

"That area where that earthquake occurred is exactly an area where there's been continuing extraction," says Frohlich.

Texas is one of the largest natural gas and oil producing states accounting for 30% of the total US output according to Forbes.