I just felt an earthquake!

[Jamie D]

@ 10:14 pm local time in Southern California

USGS Earthquake Hazards site places epicenter offshore near Santa Barbara Island.

Preliminary magnitude 4.0

From me, that's about 40 miles away.

[Jamie D]

http://earthquake.usgs.gov/earthquakes/shakemap/sc/shake/15156505/

My guess - right lateral strike slip

WRONG!

[V M]

[Jamie D]

Apparently there was a M=2.3 foreshock two minutes before the M=4.0 quake.

Didn't notice that one.  Too far away for such a tiny jolt.

[Michelle G]

Didn't feel it up here by Tahoe, I'm usually pretty sensitive to those and can feel or hear them just before the shaking

[V M]

The earth quakes are one of the few things I don't miss about living in Calif. But they were so common that unless they actually did some damage we'd usually just laugh about them

[Jamie D]

Didn't feel it up here by Tahoe, I'm usually pretty sensitive to those and can feel or hear them just before the shaking

Actually what you are sensing are the first P-wave arrivals before the higher amplitude S-waves come rolling in.

P-waves are compressional waves, as are sound waves.

[Cindy]

Are you sure it was an earthquake and you weren't being naughty and felt the earth move?

Take a cold shower.

[V M]

[Jamie D]

Funny you should post that.  I once put together a teacher development guide for earthquake safety with that same title.

[Jamie D]

Are you sure it was an earthquake and you weren't being naughty and felt the earth move?

Take a cold shower.

Magnitude   4.0
Date-Time   

    * Wednesday, May 30, 2012 at 05:14:00 UTC
    * Tuesday, May 29, 2012 at 10:14:00 PM at epicenter
    * Time of Earthquake in other Time Zones

Location   33.669°N, 119.054°W
Depth   0.1 km (~0.1 mile) (poorly constrained)
Region   CHANNEL ISLANDS REGION, CALIFORNIA
Distances   

    * 48 km (30 miles) SSW (212°) from Malibu, CA
    * 56 km (35 miles) SSE (167°) from Port Hueneme, CA
    * 57 km (35 miles) SSE (164°) from Channel Islands Beach, CA
    * 59 km (37 miles) SSE (168°) from Oxnard, CA
    * 86 km (53 miles) WSW (240°) from Los Angeles Civic Center, CA

Location Uncertainty   horizontal +/- 0.6 km (0.4 miles); depth +/- 1.8 km (1.1 miles)
Parameters   Nph= 88, Dmin=21 km, Rmss=0.51 sec, Gp= 68°,
M-type=local magnitude (ML), Version=1
Source   

    * California Integrated Seismic Net:
    * USGS Caltech CGS UCB UCSD UNR

Event ID   ci15156505

[Cindy]

OK check next time before you put new batteries in.

[Cindy]

On a serious note any damage?

[Jamie D]

Not around here.  The epicenter was 35 miles offshore, about 13 miles from the closest uninhabited island (maybe some campers or a park ranger there).

Just enough of a jolt and a roll to upset the dog.

[Jamie D]

The USGS recalculated the hypocenter depth at 16. km, or 10.2 miles.  Deep, for these parts.

And the moment tensor solution shows it was on a normal fault.  Quite unexpected!

Perhaps California is slipping into the ocean! 

[Michelle G]

Jamie..

That would be the western edge of California that go for the big swim    up here on this big ol rock of the Sierra Range we will be just fine

When I bought by this place by Lake Tahoe the survey shows that there is no history of seismic activity...that works for me!

[Sephirah]

http://news.uk.msn.com/uk/market-town-is-hit-by-earthquake-2

There seem to be a lot of 'em going around.

Maybe it's the beginning of Armageddon.