An earthquake with a magnitude of 3.4 rattled the Peninsula this afternoon on the 105th anniversary of the 1906 San Francisco quake. Initially, the U.S. Geological Survey reported a preliminary magnitude of 3.8.
The quake, which occurred at 2:57 p.m., was centered about two miles southeast of Pacifica, according to the U.S. Geological Survey.
It was followed at 3 p.m. by a second, smaller earthquake with a magnitude of 1.4. That quake was centered about 2 miles southwest of San Bruno.
The first quake was felt in parts of the Bay Area including San Francisco and Oakland.
In the Menlo Park area, people reported feeling a short rattle.
An office worker in San Mateo said she felt a jolt. "I couldn't tell if it was an airplane crash or an earthquake. It was a booming jolt.
Caltrain service was not affected, and operations were not altered at San Francisco International Airport.
For more information from USGS, click here.