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USGS Says There's Only an 85 Percent Chance of a Big-ish Earthquake Near LA By 2019

Now for another installment in the continuing soap opera in the world of earthquake prediction: as you may know, a study out of NASA's Jet Propulsion Labs emerged early this week that seemed to declare a 99.9 percent certainty that Los Angeles would experience an earthquake of magnitude 5.0 or before the end of 2019 (specifically somewhere in a 100 km zone around the Whittier and Puente Hills Faults). The next day, LA's Earthquake czar, Dr. Lucy Jones, slammed the paper's findings, saying it was a study on "one arbitrarily chosen area" and not even an official NASA study (it merely came from a group of scientists within JPL). Now the the US Geological Survey (Jones's employer) is weighing in on the matter, and they're similarly skeptical, while still saying there's a high probability of an earthquake in that area.

In a statement on their Facebook page (yes, the US Geological Survey has a Facebook page), they say the findings in the JPL paper have not been scrutinized by the "long-established committees that evaluate earthquake forecasts." The paper, though published in the online journal Earth and Space Sciences, has not been evaluated by the top brass in earthquake predictions. For an earthquake prediction to truly be considered legit, apparently it has to pass through both the California Earthquake Prediction Evaluation Council and the National Earthquake Prediction Evaluation Council. Who knew that earthquake scientists could be so cliquey?

USGS seismologist Robert Graves was listed as a consultant on the JPL study, but even he has serious doubts about its findings. Graves told the LA Times that the 99.9 percent prediction "does not seem like a reasonable number" and "that level of certainty, to my knowledge, is just not attainable." Graves even doubled down in his attack by throwing out the odds of an earthquake the USGS stands behind—they claim the chance of a magnitude 5.0 or greater earthquake in the area described in the JPL paper, during the time described, is actually about 85 percent. (That's still a pretty scary high number!)

Andrea Donnellan, research scientist and lead author of the JPL study, fired back, saying the 99.9 percent prediction was not the central point of the paper. The paper was actually a study on whether the deeper layers of the earth moved during the 2014 La Habra earthquake, and if more deep layer movement could be anticipated. The 99.9 percent number, she said, was not actually a prediction of an earthquake, but a "probability of an event," and they still plan on testing their hypothesis. Donnellan might have the last laugh, though. "If an earthquake happens in three years, we're both right," she told the Times.
· USGS slams study's claim of 99.9% chance of large L.A. earthquake [LA Times]
· USGS Statement on JPL La Habra Study in the news [USGS Facebook Page]
· JPL is 99.9 Percent Sure Los Angeles Will Get a Big Earthquake in the Next Two and a Half Years [Curbed LA]
· LA's Earthquake Czar Says Not to Worry About "99.9 Percent" Chance Earthquake Prediction [Curbed LA]