Researchers say wastewater disposal can affects areas tens of kilometers away

May 2, 2014 19:03 GMT  ·  By
Study finds wastewater disposal can cause earthquakes at a considerable distance from a drill site
   Study finds wastewater disposal can cause earthquakes at a considerable distance from a drill site

As if oil and gas developing activities were not getting enough bad publicity as it was, researchers are here to tell us that, according to recent investigations, wastewater disposal can sometimes cause earthquakes to occur at considerable distances from a well.

Speaking at a meeting of the Seismological Society of America this past May 1, a group of scientists said that there was evidence to suggest that injecting wastewater resulting from oil and gas development in the underground could trigger earthquakes at tens of kilometers from a disposal well.

This means that wastewater disposal activities can have a negative impact on a region much wider than estimated in previous studies, researchers told the people present at the meeting of the Seismological Society of America.

EurekAlert informs that, in recent years, the number of earthquakes documented in central and eastern United States has increased to a considerable extent. Thus, specialists with the USGS, i.e. the United States Geological Survey, recorded an annual average of 100 quakes above a magnitude 3.0 between 2010-2012.

By comparison, it appears that, between the years 1967 and 2000, the annual average rate of earthquakes above a magnitude 3.0 reported in this part of the United States was one of just 21 events, the same source tells us.

Interestingly enough, it turns out that this increase in the number of earthquakes documented in central and eastern United States in recent years coincides with a boom in oil and gas development activities, i.e. the hydraulic fracturing of horizontally drilled wells, and the injection of wastewater in deep disposal wells in many locations.

Specialist Gail Atkinson with the Western University in Ontario Canada says that, while researching this phenomenon together with his colleagues, he found that a fairly small cluster of high-volume injection wells can trigger earthquakes tens of kilometers away.

“Our results, using seismology and hydrogeology, show a strong link between a small number of wells and earthquakes migrating up to 50 kilometers (approximately 31 miles) away,” explains researcher Katie Keranen with Cornell University.

What worries researchers is that, given the evidence at hand, oil and gas development activities can alter the potential seismic hazard in a given region. This means that, when faced with both natural seismicity and induced seismicity, facilities such as dams and nuclear power plants might have a difficult time keeping their ground.

“In some sense, from a hazard perspective, it doesn't matter whether the earthquakes are natural or induced. An increase in earthquake rate implies that the probability of a larger earthquake has also risen,” says Justin Rubinstein, geophysicist with USGS.