NBC Bay Area’s quake map shows all earthquakes recorded near the San Francisco Bay Area over the past 24 hours. San Ramon, California, appears to have broken a new earthquake record over the last two weeks: A total of 408 small quakes have shaken the East Bay city, almost four times the record set in 2003 in half the amount of time. The U.S. Geological Survey reports that as of Oct. 13, the Northern California Seismic Network had detected 408 earthquakes – at least a dozen since 10 p.m. on Monday, with other quakes spilling into the early hours of Tuesday.
Most quakes have clocked in with magnitudes ranging from 2.0 to 3.0. In an Oct. 14 interview, Senior U.S. Geological Survey research geologist David Schwartz said the swarm is not all that unusual, noting that San Ramon Valley is at the “center of earthquake swarm activity” in the Bay Area. He recalled a 2003 swarm of 120 earthquakes over 31 days in San Ramon, with the largest clocking in at a magnitude of 4.2. The biggest swarm on record in the same general area, Schwartz noted, was in 1990 in Alamo. That’s when 351 earthquakes struck over 42 days, with the largest recorded at a magnitude of 4.4. FULL REPORT