SAN RAMON, Calif. (KGO) -- At 12:43 a.m. a measure 3.2 earthquake hit the San Ramon-Dublin border, followed by a 3.1 quake a minute later.
A magnitude 3.5 temblor struck around 4 p.m. on Tuesday and just six seconds after, a weaker 2.8 quake struck.
Hundreds of earthquakes have hit in the past two weeks. The largest being Tuesday's 3.5 quake. All were centered around San Ramon on either the Calaveras Fault, or off-shoots of it.
While seismologists still say that swarms such as this are not unusual and not cause for any extra concern, they are starting to worry residents.