TECHNOLOGY: Expanding “Hot Spots” May Trigger Earthquake Fault Slips.

AND IN OTHER EARTHQUAKE NEWS:

The Transportable Array is a migrating 500-mile-wide band of 400 high-quality, portable seismographs that covers the country in a 42-mile grid from Canada to Mexico and the Gulf. The portable array started with NSF funding in 2007, beginning on the Pacific coast. Today, it has rolled across the country to the eastern edge of the Midwest, reaching from Michigan’s Upper Peninsula to Louisiana and from Ohio to Florida.

From November 2009 to September 2011, the Transportable Array covered Texas. University of Texas geophysicist Cliff Frohlich analyzed the data, paying particular attention to the state’s oil-rich Barnett Shale. After analyzing more than 1300 events and discarding quarry blasts and signals straying in from out-of-state, he identified 149 earthquakes in the region—nothing like the 400 logged last week in Brawley, but many times the 8 listed by the National Earthquake Information Center. In a recent analysis published in the Proceedings of the National Academy of Science, Frohlich persuasively demonstrated that the quakes cluster around the state’s highest-volume injection wells, those pumping 150,000 barrels of water per month (BWPM) or more into the ground.

His conclusion: “The most significant result of this investigation is that all of the better located epicenters were situated within a few kilometers of one or more injection wells…. It is possible that some of these earthquakes have a natural origin, but it is implausible that all are natural.”

Never mind that the earthquakes were minor and shallow; the anti-fracking forces will have a field day with this news.