Can lots of small earthquakes prevent large earthquakes happening?
Many small earthquakes in one area may be foreshocks of a coming large earthquake, which can be a warning of a larger quake. Unfortunately, there is no way to know if these are foreshocks, or just small earthquakes (unless a big earthquake follows, in which case they are identified as foreshocks AFTER the primary shock has come and gone). Also, this is only about fault-generated quakes, so, not volcanic-eruption related. However, yes, if you live in certain very special places where there are constant small earthquakes, then it may act like a constant pressure valve that keeps a large earthquake from building. The town of Hollister, CA, lies on the Calaveras Fault (literally, you can see where it runs through the city), and has so many very small earthquakes that it is really just “slip,” and the town “doesn’t have earthquakes.” This isn’t exactly true, as the 1989 Loma Prieta quake seriously damaged the city, but that earthquake occurred along the San Andreas fault, not the Calaveras.
