EARTHQUAKE IN SOUTHERN CALIFORNIA

USGS ^ | 7/29/08

[ZGuy]

An earthquake is now rocking the Southern California area. (I'm near Dodger Stadium)
As I post this, the USGS has not yet determined the epicenter so click on the link above for the exact location and magnitude from the USGS.

Here are the maps for California and Los Angeles:

California:

Los Angeles:

Here's the historical review of the last seven days:

[ZGuy]

I just heard that a church in Pomona had one of its exterior walls collapse outward from this morning’s earthquake. No injuries.

[ArmstedFragg]

Is Shep on an overpass in L.A. yet?

Nope, but I'm on the roof. Always wanted to fly in one of them Coast Guard helicopter...

[ArmstedFragg]

The first post hit Free Republic one minute and six seconds later. Pretty amazing.

[kingu]

CHN:	Chino	Agency: Southern California Seismic Network
	Lat: 33.9988     Lon: -117.6804     Distance: 9.2 km from epicenter
	Location: Chino, Benson Ave and Schaefer Ave

Station Comp	Max Vel (cm/s)	Max Acc (%g)	PSA:   0.3 sec (%g)	1.0 sec (%g)	3.0 sec (%g)
HNE	11.8722	14.4064	33.5548	4.5627	1.2889
HNZ	4.3797	13.1777	14.8366	2.7457	0.3668
HNN	14.4672	23.8349	64.8953	8.8384	1.1642

23938:	Walnut	Agency: California Strong Motion Instrumentation Program
	Lat: 34.0210     Lon: -117.8660     Distance: 11.9 km from epicenter

Station Comp	Max Vel (cm/s)	Max Acc (%g)	PSA:   0.3 sec (%g)	1.0 sec (%g)	3.0 sec (%g)
HNE	11.1060	14.0676	38.0877	14.5976	0.9997
HNZ	4.0990	6.1663	15.3950	5.4991	0.4998
HNN	38.5660	43.8643	102.4670	27.9953	2.2992

Huh, not sure where your numbers came from... mine came from the event listing but maybe you picked up another?

[NormsRevenge]

looking for day-bree shots?

Bricks are seen in an alleyway after falling from a building during a 5.4 magnitude earthquake in the Los Angeles, California area that struck at 11:42 a.m. local time, in Pomona, California July 29, 2008. (Danny Moloshok/Reuters)

[Pylon]

Good idea, I’m gonna throw some beers in a blue tub and head up.

[I Drive Too Fast]

When I was 14 I came down Mt. Baldy road on a 10 speed. I got as fast as 55 mph (I was speeding) and that was back in the days of no helments. Fun, but a little scary and the eyes do water quite a bit a speed. I never made it all the way up to the ski lifts. I think the second hairpin curve was as high as I made it.

[Ernest_at_the_Beach]

I am no help on that fancy stuff...

[Ernest_at_the_Beach]

I think that was what burbankkarl was commenting on upthread quite a ways...

[DAC21]

How weird.

This morning my Wife asks about where the emergency hand crank radio is? We have had it for two years and she never even made any mention of it before. Since I was flying to KC this morning, I thought she was just a bit worried being alone.

For the first time in better than a month my dog Sarah wanted in the house before I left for the Airport, we let her stay in the house when we are gone on the hot days. She wanted no part of coming in even in the hottest of days for weeks. This morning she was crying to come in. Seemed odd, but I let her come in even though today was not going to be too bad heat wise.

I get into KC at 12:10 Pacific time and there is a TV on when we got into the gate area. 5.8 quake East of LA is the headline. After a few call to work and the wife whom works in Brea. They tell me it was in Chino Hills.

And as you probably have figured out by now, why yes I live in Chino / Chino Hills (same town essentially)

I guess both of the Ladies had a premonition this morning.
A few things were knocked of the bathroom vanity, and a few
unbroken wines glasses on there sides.

Dodged one this time!

[RetiredArmy]

I was in the Seattle 6.9 one a few years ago. Now that was rocking and rolling up on the 34th floor with all the book shelves in our law library braking loose and dumping tons of books on the floor, the lights flying off the hangers in the ceiling and computers tumbling in the floor. I was under my desk, with my arm out trying to hold my computer back up on my desk!!!

[bd476]

rightinthemiddle wrote: "Yup. A lot stronger. It may be strange to say, but an earthquake at 5.8 might be a good thing...it doesn’t do a lot of damage...

In any populated area where building and roadway construction does not meet earthquake zone safety standards, where there is little to no emergency services planning and community wide earthquake preparation, a 5.4 magnitude earthquake has the potential of being a devastating earthquake, with extensive building destruction, bridge collapse and a significant loss of life.

rightinthemiddle wrote: " ..5.8 might be a good thing...it doesn’t do a lot of damage, but relieves a lot of the stress and pent up energy on the fault. That may mean a reduced chance of a much larger quake later. Thoughts, anyone?"

Regarding earthquakes relieving stress: An earthquake can actually create more stress within the fault zone, especially upon either end of the fault as well as any nearby faults. Any stress reduction from today's thrust fault earthquake would be minuscule.

~ ~ ~ ~ ~

Static Stress Changes and the Triggering of Earthquakes

by Geoffrey C.P. King, Ross S. Stein, and Jian Lin

"To understand whether the 1992 M=7.4 Landers earthquake changed the proximity to failure on the San Andreas fault system, we examine the general problem of how one earthquake might trigger another...

< Snip >

...Further, we find that several moderate shocks raised the stress at the future Landers epicenter and along much of the Landers rupture zone by about a bar, advancing the Landers shock by 1-3 centuries. The Landers rupture, in turn, raised the stress at site of the future M=6.5 Big Bear aftershock site by 3 bars...

< Snip >

...Together the Landers and Big Bear earthquakes raised the stress along the San Bernardino segment of the southern San Andreas fault by 2-6 bars, hastening the next great earthquake there by about a decade."

Static Stress Changes and the Triggering of Earthquakes

[Wuli]

Including the 11:42 AM 5.X quake centered in Chino Hills, the Chino Hills, Diamond Bar and Yorba Linda areas have collectively had the most quakes in California all day, registering about 50 of them, most below 2.0, with a few above 3.0.

[Ernest_at_the_Beach]

We seem to have different data alright....

***********************************************

WLT:

Walnut	Agency: Southern California Seismic Network
	Lat: 34.0095     Lon: -117.9508     Distance: 18.2 km from epicenter
	Location: Hacienda Heights

Station Comp	Max Vel (cm/s)	Max Acc (%g)	PSA:   0.3 sec (%g)	1.0 sec (%g)	3.0 sec (%g)
HNE	6.6177	18.4099	21.7031	6.3301	0.5300
HNZ	2.6978	7.0638	4.9292	6.1130	0.3067
HNN	13.5268	21.5266	30.2567	12.5478	0.9316

[GodGunsGuts]

Do you know any FReepers who have the “fancy stuff” down???

[kaehurowing]

God will not be mocked.

[Biggirl]

Have a question. Is the FR server(s) located in SOCA? I did not noticed any problems because of the earthquake affecting them. Thanks for posting back.

[bd476]

Alia wrote: "Can Guarantee ya... Northern CA is bracing. They always brace when SoCal gets a goody. I think we were visually taught that the San Andrea is like one long zipper; and if it popped on your end, we’d better keep an eye out on the smaller faults in the Bay Area."

Wuli wrote: "Including the 11:42 AM 5.X quake centered in Chino Hills, the Chino Hills, Diamond Bar and Yorba Linda areas have collectively had the most quakes in California all day, registering about 50 of them, most below 2.0, with a few above 3.0."

Here's something which you might find interesting:

Prelude to an Earthquake?

Berkeley Lab Scientist Studies Possible Precursors in Micro-quakes

December 8, 2005

BERKELEY, CA – A geophysicist from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has identified possible seismic precursors to two recent California earthquakes, including the 1989 Loma Prieta earthquake that wreaked havoc throughout the Bay Area.

After sifting through seismic data from the two quakes, Valeri Korneev found a spike in the number of micro-earthquakes followed by a period of relative calm in the crust surrounding the quakes’ epicenters — months before the quakes occurred.

Although more work needs to be conducted to determine whether other large quakes are foreshadowed by a similar rise and subsequent decline in small-magnitude tremors, Korneev’s analysis suggests that these peaks may be indicative of the total set of geological stresses that affect the timing and location of large earthquakes.

Understanding this total stress picture may eventually make it possible to predict destructive earthquakes within a much shorter time frame than currently possible.

“Peaks in seismic activity in the crust surrounding a fault could help signal the arrival of large earthquakes,” says Korneev of Berkeley Lab’s Earth Sciences Division. “These peaks may be a good mid-term precursor and allow authorities to declare alerts several months before earthquakes...”

Berkeley Lab Prelude to an Earthquake?

[hole_n_one]

I knew exactly what your intention was, but, at the same time, I can see how others might have misunderstood what you were trying to do.

I'm glad to see that all the ruffled feathers have been smoothed.

[al baby]

I got your message it was no joke funny in how true it could be here or on any forum