Most of Oklahoma’s latest earthquakes could be due to subsurface injection of wastewater
According to the Oklahoma Geological Survey, there is a possibility that the majority of the state's latest earthquakes were caused because of the subsurface injection of wastewater from oil and natural gas drilling operations.
Geologists said that they have been putting efforts to examine the cause of hundreds of earthquakes that have shaken the homes and the nerves of people in central and north-central Oklahoma. At central and north-central Oklahoma, the speed of oil and gas drilling has sped up in recent years.
According to statement released by state geologist Richard D. Andrews and state seismologist Austen Holland, the pace of earthquakes and geographical trends around major oil and gas drilling operations shows that the earthquakes are 'very unlikely to represent a naturally occurring process.'
As per the survey, the primary supposed source of the temblors is not fracking or fracturing that is the practice of injecting fluid under high pressure in order to create cracks in deep-rock formations. The source possibly is the injection into disposal wells of wastewater produced as a byproduct of fracking.
"The OGS considers it very likely that the majority of recent earthquakes, particularly those in central and north-central Oklahoma, are triggered by the injection of produced water in disposal wells", said the statement.
In 2013, earthquake activity in Oklahoma was 70 times greater than the rate of earthquakes previous to 2008. Every year, the geologists record an average of one and a half earthquakes of magnitude 3 or greater. Presently, the state is recording an average of two and a half magnitude-3 or greater earthquakes every day.
In 2014, the state recorded 585 quakes of magnitude 3 or greater and it is up from 109 in 2013. The rise in earthquake activity has put Oklahoma in the center of a national debate that whether wastewater disposal from oil and gas production causes earthquakes.