Oklahoma has been hit with seven earthquakes in barely 14 hours. The frequency of the earthquakes is alarming and questions are being raised if fracking is to be blamed.
The U.S. Geological Survey (USGS) recorded seven minor earthquakes that affected central Oklahoma over the weekend. On Saturday, July 12, four earthquakes were recorded in the region, including a 4.3 one in the afternoon. The rest, which occurred in the morning, ranged from 2.9 to 3.2 in magnitude on the Richter scale. These were followed by three earthquakes on Sunday, July 13, which had a magnitude of 2.6 to 2.9. Luckily, the earthquakes did not cause any injuries or damages.
But what is causing these earthquakes? Could fracking i.e. hydraulic fracturing (a method of oil and gas drilling) be the reason behind the amplification of these earthquakes?
For the uninitiated, fracking involves blasting sand, chemicals and water into the depths of the earth i.e. where the underground rock formations lie to permit gas and oil to be extracted. This process of hydraulic fracturing can cause minor earthquakes or microquakes, which usually does not register on monitoring equipment.
However, a downside to fracking is that it results in the generation of large amounts of wastewater which in turn gets driven into injection wells that lie several feet in the depths of the Earth. Scientists opine that this may fuel earthquakes as the underground pressures could increase and the faults may get lubricated because of the wastewater.
According to USGS geophysicist Rob Williams, the injection of wastewater may be the reason behind the rise in the number of earthquakes in Oklahoma. When quizzed about a bigger earthquake occurring in Oklahoma he seemed concerned.
"Given the rate of earthquakes over the last six months, it's concerning enough to be worried about a larger, damaging earthquake happening," said Williams to CNN.
Oklahoma has been struck with an average of two earthquakes that have a magnitude of 3.0 or more between 1978 to 2008. Per the USGS, from June 2009 to June 19, 2014, nearly 207 such earthquakes have been recorded in the state. The increase has apparently started since 2009, when 20 earthquakes higher than 3.0 occurred. The number increased to an alarming 43 in 2010 and sees an increase with every passing year (barring 2012). Interestingly, the increase in earthquakes corresponds with the start of fracking in Oklahoma.
The Oklahoma GS is monitoring fracking, which has often been surrounded with controversies. Fifteen permanent and 17 temporary stations are assisting in the monitoring of oil and gas extraction methods. The aim is to find out if the high pressure water pumping into 5,000 to 20,000 feet into the earth's crust because of fracking is responsible for the recurring seismic activities.
