Analysis, Mr. Spock?

As I lay half asleep, the couch shuddered intensely. Not for long, just for two or three seconds or so.

Then it was calm again.

As my eyes lay closed, the computer quickly delivered its analysis along with the cross-competing possibilities..

Earthquake? Possible. I did hear a deep rumble along with shudder. And it was intense enough to jostle and slap my brain fluids around.
Probability: 85% +

Passing heavy vehicle? Possible. Except that there was no echo of an engine or road noise. And, although this is earthquake country.. the bedrock here is stiff enough where I cant remember ever feeling sympathetic vibrations from passing trucks or its ilk.
Probability: 65% +

Mutzu the Cat, who was on the couch with me by my feet, indulging in some heavy-duty scratching? Likely.
I looked over, and he was curled up tightly into his ball, protected against the Berkeley chill, fast asleep. No indication of REM-sleep grooming.
Plus, he doesnt weigh enough to generate the inertial momentum that shook me awake.
Probability: > 40%

Passing BART train in the Berkeley tubes? Although the BART lines are a relatively short distance from where I currently am, I will hear the high-pitched whoosh, sounding like passing F-16's on distant afterburner, but I never feel vibrations.
Solid bedrock and isolation engineering at work.
Probability: > 30%

Neighbors turning up the bass, dropping furnitures, drive-by boomboxes?
Probability: > 15%

Conclusion?

That was an Earthquake.

Combine the intense shuddering, enough to feel my brain innards move around, the deep, but almost inaudible rumble.. yah, a passing earthquake.

A) Earthquakes happen several times a week along the fault lines that criss-cross the Central and Northern California area (Berkeley and Oakland sits on the Hayward fault lines). Most are of such low magnitude and short duration that they never bring attention to themselves except to seismology detectors.
If I hadnt been lying in the sunday morning quiet and going about the daily life, I wouldve not noticed this one.

B) Im not a total neophyte when it comes to earthquakes, having been through a few tremors before.

The most powerful wouldve been a 6 magnitude that lasted several seconds in Jamaica. That was my first experience in seeing (and feeling) land that seemed totally solid move laterally from side to side like Jello in front of my eyes.
I never looked at reality the same way again.

(Kingston sits very near a deep fault line that although usually relatively quiet, has produced some excitement from time to time. The most notable one in the late 1600's dropped most of the previous capital, Port Royal, into the sea.
Port Royal is not known now for having a lot of land. Or being a port. )

There were occasional low frequency tremors in Chicago that made a few of the solid buildings I was in sway back and forth, thanks to the mid-country San Madras fault several hundred miles south in the Missouri Valley taking a few mild farts. 3 to 5 magnitude farts.

Seismologists are more afraid of the waaay overdue Big One from the San Madras than they are from California's San Andreas, as the last Big One in the very early 1800's flattened the entire eastern seaboard from the Dakotas to the Atlantic.

And a few ones in New York (which also sits on several small fault lines in its granite bedrock), that I honestly didnt even notice, mistaking them for passing subway trains, construction activities or trucks. (They sounded like explosions or metal beams falling as the granite plates shifted. Again, not uncommon daily sounds in the New York triangle, where buildings are known to fall spontaneously.)

But, this was different.

The energy produced in this short episode was of such a sharp and intense magnitude that it made me lift my eyebrow.

To be honest, this is one reason I came to California. To experience the California quakes.

If I say that out loud tho, people here give me a look as if Im *beyond* daft.
Just driving along the lower levels Bay Bridge and the views afforded by the removal of flattened freeways, the result of the 89 quake, still make people here cringe.

But yeah, this was an earthquake.
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Apparently, MinJung - who isnt far from me felt it too.