Ever worry about LA Earthquake risk? (Santa Ana, Moorpark: credit, tornadoes, work)

[kidcanaduh]

I know. I'm a bit of an idiot (I D 10 T) but I would like to experience it. I was in a tornado once in 72. I was a kid. My mother was freaking out. I enjoyed it. Some people chase storms. I have no interest in being in a Hurricane, but some thrill seekers stay to ride it out or go surfing. When I went to San Fran, people were in shock. It's understandable. People wouldn't or couldn't even talk about it. The earth is so powerful it freaks me out. I know if I were in a 8 quake I'd never want to experience another one, though.

The Hector Mine quake was in the Fall, earthquake season.

Is Hector mine a real mine?

If so, is it underground mining?

[Fleet]

Originally Posted by kidcanaduh

The Hector Mine quake was in the Fall, earthquake season.

Will you stop it. Earthquakes happen in every season, including the 1906 S.F. quake (spring) and the 1952 Kern County quake (summer).

Is Hector mine a real mine?

If so, is it underground mining?

I don't know. It's probably an abandoned mine dating back to the 1800s.

[Fleet]

Originally Posted by Chelito23

Fleet,

You had some excellent points. I like the way you explained and shared your points of view.

Thanks. I'm glad you liked the info.

I would also like to add that people tend to belive in earthquake myths like "earthquake weather" or season...because we tend to remember the events that fit into these patters and forget the ones that don't.

Yeah, that's just how it is explained in some of the earthquake books. BTW, a good book on the subject is "Peace Of Mind In Earthquake Country." It should be available on Amazon.com.

Same with say pet prediction...my pets never have predicted anything...but I know other people´s animals have acted up...so there is probably something there, if you are right near the epicenter.

I think so.

I have read a lot about quakes and their mechanisms as well, and what I conclude is that quakes are very unpredictable and usually whenever a predicition is made scientifically, a quake happens in an unexpected area.

Very true. They are very unpredictable. Possibly the most unpredictable of all natural occurrences.

I remember the Japanese gov't expected a quake in Tokyo in 1995, then Kobe was hit.

The Chinese successfully predicted a large 1975 quake, but could not predict the disatrous 1976 quake.

In Socal, a major quake was expected on the San Andreas, but low and behold, the Hector Mine quake ocurred out in the desert, where the local faults were believed to be inactive. Go figure...

Yes, they can hit anywhere there are faults.

Fleet, which quakes have you been through and how have you felt them? I have been through a handful of large subduction zone quakes in Chile and Central America, and they were slower and move sideways...and then I have felt shallow moderate quakes locally and they were very fast and hard.

I've experienced all of the ones felt in the San Fernando Valley since 1971. So that would include that one (6.7 mag.) plus these:
Point Mugu, Feb. 21, 1973, 5.9 (rolling)
Imperial Valley, Oct. 15, 1979, 6.6 (barely felt)
Palm Springs, July 8, 1986, 6.0 (rolling)
Whittier Narrows, Oct. 1, 1987, 5.9 (a quick rolling motion)
Superstition Hills, Nov. 23, 1987, 6.2 (distant rolling motion)
Superstition Hills, Nov. 24, 1987, 6.6 (distant rolling motion)
Sierra Madre, June 28, 1991, 5.8 (rolling)
Joshua Tree, Apr. 22, 1992, 6.1 (distant rolling)
Landers, June 28, 1992, 7.3 (moderate rolling)
Big Bear, June 28, 1992, 6.6 (quick rolling)
Northridge, Jan. 17, 1994, 6.7 (I am about 3.7 miles from the epicenter of that one. A brief rolling motion, then 15-20 second of very strong up-and-down shaking. A 5.9 aftershock shortly after the main shock. Many aftershocks lasting for weeks and months.)

[kidcanaduh]

Originally Posted by Fleet

Northridge, Jan. 17, 1994, 6.7 (I am about 3.7 miles from the epicenter of that one. A brief rolling motion, then 15-20 second of very strong up-and-down shaking. A 5.9 aftershock shortly after the main shock. Many aftershocks lasting for weeks and months.)

Fleet, can you describe in more detail what it feels like. You say a rolling motion. Not sure if you were indoors or out when it hit, but if you were indoors, sitting in a chair, what kind of movement was there? Did you house, chair move inches forward then backwards? Is this what you mean by rolling?

The up and down shaking. Did you actually feel the house move up and down, like the earth was rising and falling?

[cre8]

Originally Posted by kidcanaduh

Fleet, can you describe in more detail what it feels like. You say a rolling motion. Not sure if you were indoors or out when it hit, but if you were indoors, sitting in a chair, what kind of movement was there? Did you house, chair move inches forward then backwards? Is this what you mean by rolling?

The up and down shaking. Did you actually feel the house move up and down, like the earth was rising and falling?

Ok, I'm not Fleet, but I can give you a description. During the '94 Northridge quake, I was asleep in my 1920s-era house around 40 miles from the epicenter. The likeness of our house being thrown back and forth was that of being on a boat in big seas. The house sea-sawed back and forth, creaking and cracking, doors slamming open and shut, book cases, "thump, thump, thump" against the walls. Down the hall in the kitchen, you'd hear cabinet doors opening and slamming shut, interrupted by the sounds of clanking and smashing glassware. Outside you'd hear a "phszzztt!" as the transformers blew. Light posts swaying several feet from side to side. You get your bearings fairly quickly; I was awake and on my feet in a second or two of feeling the shaking. In less than a minute the whole thing is over. That's when your heartbeat, breath and reality catch up to you, and immediately the questions start: ok, who's hurt? What's damaged? Is anything on fire? Can we smell gas? Electricity is out! Get the flash light. Anyone have portable radio? Where was the epicenter? How big was it? Right about that time the aftershocks start.

[Fleet]

Originally Posted by kidcanaduh

Fleet, can you describe in more detail what it feels like. You say a rolling motion. Not sure if you were indoors or out when it hit, but if you were indoors, sitting in a chair, what kind of movement was there? Did you house, chair move inches forward then backwards? Is this what you mean by rolling?

The main shock was at 4:31, so I was sleeping in the second story of a two-story wood-frame house. Actually, I was kind of in between sleeping and awake. The rolling motion was the P-wave (primary). That lasted for about 5 seconds, then the S-wave hit (secondary). That is where the power is.
It was a violent, up-and-down shaking which lasted 15-20 seconds. Loud, too. A lot of items fell (bookshelves, lamps, TVs, etc). The refrigerator in the kitchen moved about 4 feet forward and the water heater was jiggled around so much that it sprung a leak. The house, of course, moved a lot but since it is bolted to the foundation, there was no significant damage.
Overall, the house came through it fine. It was built in 1964 and I suppose they were built well back then.

The up and down shaking. Did you actually feel the house move up and down, like the earth was rising and falling?

It was too dark to see much (and the power went out during the EQ). But with a quake that large, the house definitely did move up and down because the ground below it was.

For the next week or so, there was an average of one aftershock per hour. (Not all of them felt, but most of them.)
For the first 3-4 days after the quake, I was only getting about 2 hours sleep per night (all that shaking).

I hope I don't have to go through that for a while; I hope that will be the last big quake in the San Fernando Valley.

[kidcanaduh]

Thanks guys. I forgot that it happened at 4:30 am. Seems God times them so few people get hurt. Almost everyone was asleep for Northridge. San Fran had many at the ball game instead of on the roadways.

I forgot to watch what time it got dark tonight. Did you remember to check?

I looked on the wayback machine for my link to the message I posted on the Discovery channel website in jan. '05. They have links to the forum and the forum archives every month but... you guessed it, Jan. '05. It ends in Dec. '04 and starts again in Feb. '05.

[Fleet]

Originally Posted by kidcanaduh

Thanks guys. I forgot that it happened at 4:30 am. Seems God times them so few people get hurt. Almost everyone was asleep for Northridge. San Fran had many at the ball game instead of on the roadways.

Fortuantely, the '94 Northridge quake, along with the '71 Sylmar quake, happened in the early morning.

I forgot to watch what time it got dark tonight. Did you remember to check?

Yeah, sunset was just before 5:00 PM and it was dark by 5:20... same as always for this time of year. There goes your theory!

Incidentally, I used to cut the weather section out of the newspaper everyday.
Here is a comparison:

Los Angeles, Calif.
Sunset: Dec. 31, 2007: 4:54 PM
Sunset: Dec. 31, 1992: 4:56 PM

Sunrise: Dec. 31, 2007: 6:59 AM
Sunrise: Dec. 31, 1992: 6:58 AM

See just about the same... no "one hour" later daylight! Sorry.

[kidcanaduh]

Well, in Jan. '05 it was different, even in Cali. It was a Cali guy to pointed it out to me, and it was happening here as well. That's why I posted the message on the Discovery Channel, to find out why. Never got an answer though.

[Fleet]

Originally Posted by kidcanaduh

Well, in Jan. '05 it was different, even in Cali. It was a Cali guy to pointed it out to me, and it was happening here as well. That's why I posted the message on the Discovery Channel, to find out why.

Would you post a link to a (credible) article showing what you claim? I watch the sunset for a few mintues every night and there was no "extended daylight." The sun set at the same time as is listed in the newspapers each day.

Never got an answer though.

I'm not surprised there was no answer since it didn't happen.