San Ramon residents have been rattled by dozens of small earthquakes in the last two months. The pattern continued Thursday morning, with two small quakes — a 2.0 and a 2.4 — centered just southeast of City Center Bishop Ranch.
It’s been decades since the region experienced such high levels of seismic activity. In November, San Ramon experienced 19 earthquakes stronger than magnitude 2, more than any month since 1976. And December was even shakier, with 38 by Dec. 18.
The large numbers were due to earthquake swarms, sequences that involve small earthquakes repeatedly occurring in the same region…