Pair of Small Earthquakes on Hayward Fault Shake East Bay

A 2.9 magnitude earthquake struck in the Berkeley hills around 8:45 a.m. Saturday, and just a few hours later, a 2.7 quake hit near Mills College in Oakland at 12:35 p.m., according to the U.S. Geological Survey (USGS).

People reported feeling the Berkeley quake as far south as the Peninsula and Hayward and as far north as Concord and San Pablo, with the Oakland quake leaving a smaller footprint in just Oakland and Alameda. No damage has been reported.

Both earthquakes occurred along the Hayward Fault, which geologists have called a "tectonic time bomb," waiting to cause a massive earthquake.

Paul Caruso, a geophysicist with the USGS, said it's too soon to tell whether the two earthquakes were connected.

"These being this small magnitude and not following a larger earthquake, it's just pretty typical for California," Caruso said. "We have lots of earthquakes every day."

There have been more than a dozen small earthquakes in the East Bay with a magnitude of at least 1.1 in the last three weeks, according to USGS data.

In January, the Hayward Fault produced earthquakes of slightly larger magnitudes — 3.5 and 3.4 — on back-to-back mornings. Those quakes led to brief delays on BART. Saturday's quakes did not cause any transit disruptions.