An anniversary quake

Today, 18 April 2011, is the 105th anniversary of the great San Andreas fault quake that devastated San Francisco in 1906.

What better day, then, for the Bay Area to experience another temblor?

According to the U.S. Geological Survey, the quake occurred at 3 PM Pacific time, measured just 1.4 and was centered at 37.603°N, 122.452°W, which is on the Peninsula between Pacifica and San Bruno.

Felt more like a 3 or 4 to me, but there are always caveats when judging a quake's intensity:

• The preliminary measurement by agencies like the USGS is almost always revised a little bit down the line. The recent Japan quake, for instance, went from an 8.9 to a 9.0.
  
• One's perception of a quake depends heavily on where one experiences it -- both one's distance from the epicenter and the type of ground on which you're standing (or sitting, or ...).
  

UPDATE: It seems I was looking at the wrong quake report. USGS reports another one that occurred at 2:57 PM Pacific and measured 3.8, which feels a lot more like the one I experienced. It was centered at 37.597°N, 122.455°W, not too far from the 1.4, which now looks like an aftershock. Both quakes took place more than 12 km beneath the surface.

UPDATE: According to a California/Nevada fault map centered at 37°N, 122°W, both quakes occurred on the San Andreas Fault. Isn't coincidence wonderful?