Earthquake Strikes San Ramon Saturday Morning

SAN RAMON, CA — A 2.6 magnitude earthquake hit San Ramon Saturday morning, just 12 hours after a swarm of five earthquakes hit nearly the same spot.

The latest of a series of regular quakes hit at 8:10 a.m. Saturday, centered just west of Alcosta Boulevard. The quake had a depth of 9.1 kilometers, and users around the Tri-Valley reported feeling it weakly.

From 7:41 p.m. to 7:57 p.m. Friday, five earthquakes struck San Ramon. The largest was a 4.0 at 7:49, followed shortly by a 3.8. This was preceded by earthquake swarms Monday and Tuesday.

In the past month alone, San Ramon has seen nearly 150 earthquakes, its second highest number in nearly 50 years, according to the San Francisco Chronicle.

The city sits along the Calaveras Fault, and several micro-faults along the main fault result in swarms of quakes. When fluids like water or gas move through a complex web of cracks in tiny faults, this can trigger many dozens of small quakes in quick succession.

SEE ALSO:

• Earthquake Swarm Rattles San Ramon For The Third Time This Week
• Earthquake Swarm Rattles Bay Area Overnight. USGS Weighs Chances Of Bigger Ones To Come
• Morning Quake Rattles The East Bay
• Why Does San Ramon Get So Many Earthquakes?