Hyrdraulic Fracking Causes Earthquakes, Study Finds

Santa Cruz, CAAccording to results from a new study just published in the prestigious journal Science, there is a direct association between injecting water into the ground and earthquakes: injecting water into the ground is a practice used in the highly controversial natural gas extraction technique known as hydraulic fracking or fracturing.

The study looked at geothermal energy production the state of California, where the practice is to extract water from the ground then inject water back in. The researchers evaluated 30 years of data from a CalEnergy geothermal field near the Salton Sea. The researchers found that the practice has triggered a series of small earthquakes very close to the San Andreas Fault. This finding has huge implications for the state, and for states across the country where hydraulic fracking is done.

"We're not the first people to ever say that pulling fluid out of the ground is causing earthquakes, but the demonstration here is much clearer," said the study's chief author, UCSC geophysicist Emily Brodsky. "It's a very strong signal. This is not subtle."

According to a report in the Santa Cruz Sentinal Ernest Majer, a senior adviser at Lawrence Berkeley National Laboratory geophysics department and an authority on the topic, as far back as the 1930s, oilmen around Long Beach noticed they needed to replace oil with saltwater or the ground would shake. "Reinjecting water and taking water out of the ground has been long known to cause seismicity," Majer he told the Sentinal.

Fracking was determined to be responsible for a series of small earthquakes around the Barnett Shale area of North Texas, according to a study published in 2012, by the University of Texas. Further, in March, scientists published a study that determined fracking was responsible for a 2011 5.6-magnitude Oklahoma quake, stating that a relatively small wastewater injection triggered a cascade of small earthquakes that became a larger one.

Hydraulic fracturing is a means of extracting natural gas, oil, petroleum and other substances from shale rock layers. In addition to the concern over earthquakes, issues around the impact of hydraulic fracturing on surrounding groundwater have also been raised. As a result, the Environmental Protection Agency (EPA) is undertaking studies and analyses of the possible effects of hydraulic fracturing on drinking water resources. The study is expected to be completed in late 2014.

Among the concerns the EPA cites:
• Stress on surface water and ground water supplies because of the use of water in hydraulic fracturing;
• Contamination of underground sources of drinking water and surface water; and
• Air pollution caused by release of chemicals and gases into the surrounding air.