Oil Recovery May Have Triggered Texas Tremors

ananyo writes "First came reports of earthquakes caused by hydraulic fracturing and the reinjection of water during oil and gas operations. Now U.S. scientists are reporting tremors may have been caused by the injection of carbon dioxide during oil production. The evidence centers on a sudden burst of seismic activity around an old oil field in the Permian Basin in northwest Texas. From 2006 to 2011, after more than two decades without any earthquakes, seismometers in the region registered 38 tremors, including 18 larger quakes ranging from magnitude 3 to 4.4, scientists report in the Proceedings of the National Academy of Sciences. The tremors began just two years after injections of significant volumes of CO2 began at the site, in an effort to boost oil production. 'Although you can never prove that correlation is equal to causation, certainly the most plausible explanation is that [the tremors] are related to the gas injection,' says Cliff Frohlich, a seismologist at the University of Texas Institute for Geophysics in Austin, who co-authored the study."

Comments

Re:But is this....bad?

[alexander_686]

...my understanding of fault lines is that there are areas where tectonic plates cross, with one moving over the top of the other, pushing one down and one up. So far so good right?

Half right. Sometimes it cause by plates rubbing against each other but there are other ways to create earthquakes. Since Texas is far away from any fault lines that I know of I don’t think this is the case.

http://en.wikipedia.org/wiki/Intraplate_earthquake

So the model I have understood is, the fault compresses over time as the plates move, and then an earth quake happens when the stress is suddenly released, allowing the plates to slip some amount, relieving the stress and starting the process over again from its new position.

So now if this is an accurate enough description of the process, it seems to me like more frequent, smaller quakes are likely preferable to less frequent larger ones. So could this triggering of earth quakes actually be a....good thing? Is that question even being asked?

It has been asked and the answer is maybe. The energy of small earth quakes is trivial to that of large earthquakes. Small earthquakes might just transmit the stress down the fault line resulting in larger earthquakes later. The current models are not very good and this sort of stuff so no answers yet.