A total of 12 earthquakes were recorded Wednesday near the Crow Canyon Country Club in southeast Danville near San Ramon. The swarm began shortly before noon and occurred within the course of 44 minutes.
The largest quake, which was the first at 11:43 a.m., was downgraded from a preliminary magnitude 4.2 to a 3.8, according to the U.S. Geological Survey. The USGS recorded the depth at about 6.8 miles.
The quake magnitudes range from 1.3 to 3.8 — the latest struck at 12:27 p.m. at a magnitude 1.6 and 5.8-mile depth.
There are no known reports of damage.