Many of the state’s largest earthquakes have struck near the junction, where the Pacific, North American and Gorda plates meet. This area also forms the boundary between two infamous threats: the San Andreas Fault system, which runs across most of California, and the Cascadia subduction zone, which goes up to Vancouver Island, Canada.

The area around San Ramon has recorded 91 quakes stronger than magnitude 2 over November and December, through Tuesday morning. That tally is the highest on record for the area for a two-month period, according to a Chronicle analysis of U.S. Geological Survey data.

A small earthquake was felt in the San Francisco Bay Area. (Quakebot) A magnitude 3.2 earthquake was felt in the San Francisco Bay Area on Friday evening. The latest earthquake, which occurred at 5:03 p.m. Friday, was centered above a residential ...