A swarm of small earthquakes jolted San Ramon over the last month. Scientists said the earthquakes are normal and aren’t indicative of the big one.

A 3.1 magnitude quake struck near San Ramon early Tuesday, part of a recent East Bay swarm. No damage reported, but experts urge preparedness.

A swarm of at least six earthquakes reaching up to magnitude 2.9 rattled San Ramon near San Francisco, the U.S. Geological Survey reports.