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Trio of earthquakes gently shake Berkeley early Saturday

October 22, 2011 11:26 am by Tracey Taylor


Three relatively small earthquakes occurred on the Hayward Fault in the early hours of Saturday October 22 — all of them centered in the Claremont neighborhood of Berkeley. This follows the series of four that rattled Berkeleyans on Thursday.

The first tremblor happened at 12.06 am and was a magnitude 2.8, according to the USGS, with a depth of five miles. The epicenter was near Tunnel Road not far from where Thursday’s quakes were centered.

A 1.3-magnitude quake followed swiftly at 12:14 a.m, with its epicenter at The Plaza Drive, also in the Claremont neighborhood; and a third one, listed as 2.5 magnitude, at 12:45 a.m, was also just off Tunnel Road, between The Uplands and El Camino Real.

4 Comments

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  • Anonymous

    I was actually just falling asleep when the one around midnight hit.  If I had been walking around I probably wouldn’t have noticed it, but in a quiet house you could just make out the faint vibration and the sound of the windows rattling.

    Let’s hope they keep going DOWN in magnitude, and don’t ramp up to “the big one.”

  • the deer!

    It is more likely that these get smaller as they continue, and usually it’s a good sign that there are many small quakes and aftershocks all together..and that the initial one wasn’t HUGE. Pressure release is good! But, you never know. Being more prepared for the Big One is a good idea with all of these reminder shakes..

  • Redrocksrover

    As I understand it, pressure release via small quakes isn’t really as beneficial as you might think. The Richter scale is logarithmic, not linear, so a 5.0 quake releases 31.6 times more energy than a 4.0. In other words, there would have to have *a lot* of small quakes to release the energy of a large quake.

    In the weeks leading up to the March 11, 2011 9.0 “N Honshu” quake in Japan that led to the tsunami, there were a series of foreshocks in the same general region. Prediction of quakes by monitoring foreshocks isn’t well understood, but all of these quakes we’ve been having that center in the same geographic area *could* be foreshadowing of a larger event rather than a dissipation of energy.

    Get prepared. It’s just a matter of time anyway. http://72hours.org/

  • Heather W.

    I’m considering these smallish quakes a forewarning, Redrocks, as you note about the Japan quake, they had a series of smaller ones the week or so preceeding the biggest ones — and then the aftershocks were huge unto themselves. Need water and batteries, for sure!