LAUSR

Tiny earthquakes stitch together big ones The earthquakes that make the news are usually the big ones. For example, the magnitude of the 2004 Indian Ocean earthquake that resulted in a quarter million casualties was 9.2. The 1906 San Francisco earthquake was a magnitude 7.9. The catastrophic 2010 Haiti earthquake was a magnitude 7.0. Human-induced earthquakes as large as magnitude 5.8 in Oklahoma have caused some building damage and much public consternation. But below magnitude 3, few people are likely to feel an earthquake, even in populated areas. On page 767 of this issue, Ross et al. (1) reanalyzed southern California seismic data from 2008 to 2017 with the goal of finding all the earthquakes between magnitude 0.3 and 1.7 that were previously missed.