Predicting earthquakes is all but impossible, but a new study is being hailed as an important first step. The takeaway: Big quakes are preceded by smaller ones, reports the Los Angeles Times. Researchers took advantage of a new technique developed to find previously undetectable "microquakes," some as small as negative 2 magnitude. Poring over what National Geographic labels a "massive dataset" of big and small California quakes based on that technique, the researchers found a clear pattern: Between 2007 and 2018, 72% of Southern California earthquakes of at least magnitude 4 were preceded by smaller quakes. “It’s very much a first step and big leap forward in improving our understanding of earthquake processes,” says geologist Wendy Bohon of the Incorporated Research Institutions for Seismology, who was not a part of the study.
Researchers are emphasizing that "first step" part—that we're a long way from being able to make reliable predictions based on existing data. But the research suggests that statistical forecasts are a future possibility—for example, if computers detect microquakes close to a fault. "It's a little like the history of weather forecasting, where it has taken hundreds of years of steady progress to get where we are today," says Daniel Trugman of Los Alamos National Laboratory in a press release. He is co-author of the new study in Geophysical Research Letters. The study notes that most small quakes fizzle out without leading to anything bigger, but the study could help scientists better understand when those smaller quakes become something to worry about. (Read more earthquake stories.)