Thanks To Fracking, Earthquake Hazards In Parts Of Oklahoma Now Comparable To California

http://www.forbes.com/sites/jamesconca/2016/09/07/the-connection-between-earthquakes-and-fracking/#3b52829d7f65


Figure 1. Earthquakes greater than magnitude 3 in the central and eastern United States from 1973 to April 2015. Two abrupt increases in the earthquake rate occurred in 2009 and 2013, coinciding with dramatic increases in fracking for gas and oil. Blue dots represent earthquakes that occurred between 1973 and 2008, and red dots represent earthquakes that occurred between 2009 and April 2015. Prior to 2009, earthquakes were spread across the United States. Beginning in 2009 the earthquakes are tightly clustered in a few areas including central Oklahoma, southern Kansas, central Arkansas, southeastern Colorado and northeastern New Mexico, and multiple parts of Texas. Source: USGS

A magnitude 5.6 earthquake shook Oklahoma on Saturday, tied for the strongest quake ever recorded in the state. Odds are it was triggered by fracking operations, specifically the subsurface injection of fracking wastewater and produced waters in general, even from non-fracking operations.

There is a connection between fracking and earthquakes in the central and eastern United States (Figure 1). But the earthquakes are not a result of fracking itself. They mostly result from the injection of fracking wastewater and other waste and production water, even from non-fracking wells, at depths well-below the fracking horizon. The larger the volumes of water injected into the subsurface, the larger the earthquakes can be.

The United States Geological Survey just produced a seismic hazard forecast for 2016 for the central and eastern United States that includes both induced and natural earthquakes. While almost all of the fracking-induced or triggered earthquakes are small — less than magnitude 3, which can’t be felt by most people — enough are above 3 that the USGS predicted a 5% to 17% chance of significant damage to homes and structures in just the year 2016 for areas of north-central Oklahoma and southern Kansas where fracking occurs. Presumably, this will continue each year as long as fracking continues close to the present rate.

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