Oklahoma earthquakes linked to oil and gas exploration

Seismologists with the Oklahoma Geological Survey have linked minor earthquakes that occurred in Oklahoma, US, over the weekend to shale gas exploration in the region.

The US Geological Survey recorded earthquakes of magnitudes of 2.9 and 3.8 around central Oklahoma north of Oklahoma City on Saturday.

Although most earthquakes occur naturally, some have been linked to underground oil and gas exploration, which can result in the alteration of pressure points, causing shifts in the earth. It is suspected by scientists that the disposal of wastewater from fracking contributes to earthquake activity.

Spurred by US efforts for energy independence, recent years have witnessed a rise in oil and gas exploration across the country, including modern hydraulic fracturing. This involves millions of gallons of wastewater being trucked from a fracking site to wells where the water is injected deep into porous rock layers.

If the work is performed near a fault, there are chances that it can trigger seismic activity.

Oklahoma suffered a 5.6 magnitude earthquake in November 2011 which damaged more than a dozen homes and businesses. The state recorded 278 earthquakes in total from 2008 to 2013.