Before Fracking, Oklahoma Had 1 Earthquake Per Year. This Year, They Have Already Had 230.
A new study published in Science magazine found that hydrofracking has directly led to a massive spike in earthquakes in Oklahoma.
According to the study, Oklahoma saw almost no seismic activity, averaging just one earthquake with a magnitude of 3.0 or greater per year until 2008. This year, the state has already seen 230 earthquakes with a 3.0+ magnitude.
Cornell University’s Geoffrey Abers told Nature magazine that “it is really unprecedented to have this many earthquakes over a broad region like this.”
“Most big sequences of earthquakes that we see are either a main shock and a lot of aftershocks or it might be right at the middle of a volcano in a volcanic system or geothermal system,” he said. “So you might see little swarms but nothing really this distributed and this persistent.”
The authors of the study found that just a small number of waste-water injection sites could be responsible for the massive spike across the entire state. Researchers think that hydrofracking is “overpressuring” a fault system. Injecting a large amount of waste-water into the ground causes typically stable areas to “slip” which redistributes pressure across the entire fault system.
“The risk of humans inducing large earthquakes from even small injection activities is probably high,” Abers said. “Some of these earthquakes are as much as 20 miles away from what seems to be the primary wells that are increasing the pressure. I think this rate of earthquake increase in the midcontinent is really extraordinary and is continuing, but this isn’t the last work on this by any means.”