Texas tremors may be linked to gas injections

Nature : A series of recent tremors in Texas has been associated with the injection of carbon dioxide gas into oil wells to enhance production. Between 2006 and 2011, some 93 tremors, including 18 earthquakes of magnitude 3 or greater, were recorded near the Cogdell oil field in northwest Texas, according to a recent study by researchers at the University of Texas at Austin. The area had experienced similar seismic activity between 1957 and 1982, associated that time with the injection of water into the wells. In 2004 the injection of CO₂ gas was initiated. Because of the lack of similar seismic activity in nearby oil fields, however, the researchers say that an unidentified fault running through the Cogdell area may ultimately be to blame. Their study may not prompt the cessation of CO₂ injections in the area,but it does point up the potential problems involved with carbon capture and sequestration , one of the methods proposed to lower power plants’ carbon emissions and manage climate change.