4.2 Quake in the Newhall Area of So Cal

[sce56]

Source: SCEDC





== PRELIMINARY EARTHQUAKE REPORT ==

Southern California Seismic Network: a cooperative project of
U.S. Geological Survey, Pasadena California
Caltech Seismological Laboratory, Pasadena, California



Version #1: This report supersedes any earlier reports of this event. This event has been reviewed by a seismologist.

A light earthquake occurred at 1:47:07 PM (PDT) on Thursday, September 1, 2011.
The magnitude 4.2 event occurred 7 km (4 miles) ESE of Newhall, CA.
The hypocentral depth is 0.1 km (0.1 miles).



Magnitude 4.2 - local magnitude (Ml)
Time Thursday, September 1, 2011 at 1:47:07 PM (PDT)
Thursday, September 1, 2011 at 20:47:07 (UTC)
Distance from Newhall, CA - 7 km (4 miles) ESE (110 degrees)
Pacoima, CA - 8 km (5 miles) N (349 degrees)
San Fernando, CA - 8 km (5 miles) NNW (348 degrees)
Los Angeles Civic Center, CA - 39 km (24 miles) NNW (330 degrees)
Coordinates 34 deg. 21.4 min. N (34.356N), 118 deg. 27.3 min. W (118.455W)
Depth 0.1 km (0.1 miles)
Quality Fair
Location Quality Parameters Nst=140, Nph=140, Dmin=6 km, Rmss=0.58 sec, Erho=0.3 km, Erzz=0.7 km, Gp=21.6 degrees
Event ID# ci11001205
24-hour Aftershock Forecast Map

Read more: http://www.data.scec.org/recenteqs/Quakes/ci11001205.html

---

I did not feel it as I'm at home on my boat but it was Just a light shaker

[laconicsax]

1. Yawn.

[kestrel91316]

3. Easy for you to say. SOME of us have PTSD from the Northridge quake and

now every little jolt causes a severe, acute physiologic reaction due to epinephrine release.

[sce56]

4. Well that was simple since I did not feel it my waterbed absorbs all those shocks!

But if a Tsunami was to happen I would feel it last march the slips almost came off the pilings at 2 in the morning I was told it came within 4" of loosing it as I slept on my boat.

[laconicsax]

7. I've been through lots of quakes.

Including the 2001 Nisqually earthquake which was bigger than Northridge. 4.2 doesn't phase me and reading about one in LBN makes me yawn.

[Name removed]

16. Deleted message

Message removed by moderator. Click here to review the message board rules.

[laconicsax]

18. Stay classy, kestrel. n/t

[kestrel91316]

2. Felt it here in the San Fernando Valley. This one was right about

at Placerita Canyon park, by the looks of the map

[Irritable Liberal]

5. Didn't feel it in Sherman Oaks

But the Northridge quake destroyed my condo.

[dhill926]

6. Hmmmm......

thought I felt a bit of a bump. Wow.....

[cbayer]

8. Also on a boat in Cat Harbor. We are having some wacky sea states over here.

Big surge since yesterday afternoon, predicted to peak at 20 feet this afternoon. Hillsides and dirt roads being washed out.

I don't know if it is related to seismic activity, but I haven't seen any other explanation for it.

:shrug:

[MsKandice01]

9. Just saw this...

"While the surf, brought to the region by a southwest swell that originated off the coast of New Zealand, is expected to mellow starting Friday, waves will be larger than normal through the Labor Day weekend."

http://latimesblogs.latimes.com/lanow/2011/09/high-surf-to-peak-today-in-southern-california-1.html

[cbayer]

10. Thanks for that! All the way from New Zealand - wow.

:hi:

[sce56]

11. Yesterday that the surf was so high it flooded onshore

http://latimesblogs.latimes.com/lanow/2011/09/high-surf-to-peak-today-in-southern-california-1.html

The unusually high surf that has been pounding the Southern California coast will peak Thursday, forecasters said, prompting warnings of possible coastal flooding and treacherous swimming conditions at the beach.

The National Weather Service has issued a high-surf advisory through 5 p.m. Friday, warning of up to 11-foot waves on south- and southwest-facing beaches.



And if you go here you can see a photo from yesterday in Newport Beach
http://latimesblogs.latimes.com/lanow/2011/08/high-tides-flood-streets-near-balboa-pier.html

Areas near the Balboa Pier in Newport Beach flooded Wednesday due to high tide and surf increase, according to lifeguards. A 6-foot tide at 11:20 a.m. flooded streets and closed two parking lots near the pier, said lifeguard Capt. Boyd Mickley. The closed lots included the parking lot on the side of the pier and the lot on A Street, Mickley said. "Cars that were in the front row of the parking lot were picked up and moved to the back row," said James Jackson, a Newport Beach lifeguard. "That one set that came in right at 11:30 was pretty massive...pretty massive," Jackson said.

[cbayer]

12. Great picture from Newport. We just talked to a friend in Marina del Rey who said

the waves were coming over the breakwater.

I've been out here 6 years and never seen a surf like this in the harbor.

:hi:

[sce56]

19. Now that I think ablout it the noise has been a bit higher lately as the boat goes up and down with

tide lately! I don't think it has much to do with it but maybe I'm pretty far into the harbor and have been seeing an upswing in the sealions here the past few days!
BTW I like your sigline I need to find one similar to that.

[shanti]

27. woah!

i grew up in the OC and never saw anything like that before!

[AtheistCrusader]

13. I don't worry about the little ones.

They release strain, lessening the chances of an ass-kicker. And if it's a foreshock, you can't know anyway till the mainshock comes.

Don't worry, be happy, but know where shelter/exits are at all times.

[jaysunb]

14. Didn't feel it in Pasadena. n/t

[DCBob]

15. wimps.

;)

[sce56]

17. Hey you wanna come over here and say that to us while standing on the San Andreas Faullt?

Well anyway when the Northridge quake struck I was out in your neck of the woods my last few months before I retired from Ft. Belvoir VA. My sister lives in Potomac and had lost some dish last week.

[DCBob]

21. nah.. I prefer our local, less shakey fault.

[dogmoma56]

20. could be foreplay for the next big one...

:popcorn: :hide: :yoiks:

[MineralMan]

23. Probably not. That area has earthquakes frequently. It always has.

Just another smallish earthquake. I grew up less than 10 miles from where this quake was. I've felt dozens of them that size.

[MineralMan]

22. My parents and siblings will have felt that one, I'm sure.

They don't live far from there, as the crow flies. I'll ask them about it when I talk to them on Sunday.

[necso]

24. Data update:

Depth: 7.3 km (4.5 miles)

USGS page:

http://earthquake.usgs.gov/earthquakes/recenteqsus/Quakes/ci11001205.html

Early data is often corrected as the earthquake is better "fixed". ("The hypocentral depth is 0.1 km (0.1 miles).": 0.1 km is shallow for an earthquake, especially for an earthquake of significant magnitude.)

Tectonically, this is a (very) interesting area. As the second map on the following page illustrates, it's "along" a section of the San Andreas where it "flattens" out (although not the "flattest" area), and is an area of transverse (roughly EW) morphological features.

http://neic.usgs.gov/neis/recent/ci11001205_l.html

And as the map on the next page shows, there's a lot of (recognized) faulting (fracturing).

http://earthquake.usgs.gov/earthquakes/recenteqscanv/FaultMaps/119-34.html

(I had more; but an adequate treatment of the subject matter seems impractical here and now.)

[sce56]

25. I suppose the mountains there must have risen a few Centimeters today. n/t

[necso]

26. Sometimes

earthquakes have no noticeable surface displacement effects (not exactly the same as being a blind fault).

Here's kind of a cool (SCEC) page:

http://www.scec.org/education/public/allfacts.html

[onager]

28. Yawn here too...

I live just a couple miles from the epicenter of the Northridge quake.

Weirdest sight that morning - flames from the burst gas lines floating on top of water from the broken water mains.

Attack ships on fire off the shoulder of Orion...c-beams glitter in the dark near the Tanhauser Gate...

Oh...never mind...