A recent study published in in Earth and Space Science that claims a massive earthquake has a 99.9% chance of hitting Los Angeles within the next three years is under fire from the U.S. Geological Survey. The organization issued a statement about the study, doubting its accuracy and scrutinizing its conclusions.
The study suggested that the impending California earthquake would be a magnitude 5 or more and would rattle Los Angeles between April 1st of this year and April 1st of 2018. The study, and the speculations of an enormous west coast earthquake have been in the news and in our minds recently, and while it is a good idea to be prepared for natural disasters, the U.S.G.S.’s disavowal of the study is at least mildly comforting.
Robert Graves, an USGS seismologist and Southern California coordinator for earthquake hazards, said that he has deep concerns about the study, though he is listed as a consultant for the paper. “The 99.9% number—I don’t know the method that was used to derive that. But basically, that’s saying [the earthquake] is going to happen. And that level of certainty, to my knowledge, is just not attainable. We can never be that certain.”
In response, the lead author of the paper, Andrea Donnellan, said that the 99.9% figure should not be the focal point of the paper as that conclusion was not the work’s central purpose. But with a number as certain as that, it’s difficult to overlook, and it’s easy to see why that became the study’s talking point.
Graves believes that 85% probability of an earthquake is a more likely number than 99.9%. That’s still a very high rate of probability worth preparing for, but it is less certain. Earthquakes simply cannot be predicted with such a high rate of confidence.
So while a large earthquake is probably, it is not certainly going to happen—but prepare for one and have routes to safety planned, all the same.