Earthquakes that shook an old Texas oil field over the past few years could be due to injections of carbon dioxide gas. Previous tremors in the area were tied to wastewater injections, but these are the first events attributed to forcing pressurized gas underground.
Two years after significant gas injections began in the oil field to boost production (pictured), the area experienced a spate of small earthquakes, 18 of which reached magnitudes between 3 and 4.4. Wei Gan and Cliff Frohlich at the University of Texas at Austin have now determined the precise location and timing of the quakes.
The locations correlate with gas injection sites and suggest that slippage occurred along a previously unidentified fault. Nearby fields where gas was also injected did not show such seismic activity, however, and the researchers say that more data are needed to predict where gas injection could trigger tremors.
For a longer story on this research, see go.nature.com/x4hhn4