Earthquake!

January 28, 2002

[Thinkin' Gal]

Not an "E-Ticket", but it will do.

Hehehe, I remember the kitchen junk drawer being full of those A and B tickets. The Swiss Family Robinson Treehouse just wasn't high on our priority list. :-] Did any of the natives even get off the couch for this one?

[Tony in Hawaii]

Small world. I work in Woodland Hills. Not much in the way of woods or hills, but we do have fancy stores. :)

[Mark17]

she's still bouncing?

Is this what they call a dead cat bounce?

[Redcloak]

Much of the SF Valley has above-ground power lines. My guess is that Bernard was seeing those arcing. We saw that here in Woodland Hills.

[Redcloak]

My wife always says we live in "Woodless Hill, where there are no trees and there are no hills".

[notpoliticallycorewrecked]

I remember hearing that name. He working at the main office in down town LA but they pulled everyone for the Sylmar quake. They inspected every square foot of some of those dams. I remember that they thought that one of the dams was going to break. They evacuated the area below for a day or so until it was inspected. Don't remember the name of the dam tho.... that was his job not mine! My Mom might remember I'll have to ask her. I do remember that my cousins lived right below the dam but were outside the evacuation area, but decided to evacuate anyway.

[SoCal Pubbie]

Don't be so sure you won't experience an earthquake just because you live in Chicago! Check out post 197 for a bit about the New Madrid fault and the biggest earthquake in the history of America. I read an article in the L. A. Times years ago about this very subject, and how an even moderate quake would devastate places like Chicago. There’s too much unreinforced masonry, and absolutely no earthquake building standards.

[SoCal Pubbie]

I couldn’t believe the way the ABC station here in LA hyped this little shaker. First, they interrupted Rose Red with a ticker at the bottom of the screen with the “breaking news”, then they spent about fifteen minutes essentially saying there was no damage, no injuries, nobody called the police- nothing happened. That didn’t stop them from trying to make it the biggest catastrophe since 9/11 though!

[capitan_refugio]

There were a lot of lucky people who survived the 1971 Sylmar (aka San Fernando) Earthquake. It had a Richter Magnitude of 6.6, with a maximum recorded acceleration of 1.24. If an earthquake's acceleration exceeds 1.0, the forces overcome the pull of gravity and throw things upward (many earthqaukes throw things laterally, but only a few will do things like bounce automobiles off the ground).

The Van Norman Reservoirs, part of the Los Angeles aquaduct system, nearly failed. The Lower Reservoir (there were two, Upper and Lower) broke its liner and began to leak. If the earth-fill interior had blown out, it would have been all over for hundreds or thousands of people just below the reservoir in the San Fernendo Valley. The difference might have been about 10-15 seconds more violent shaking. As it was, the emergency spill gates were opened the the Lower Reservoir was quickly drained.

[notpoliticallycorewrecked]

Thanks for the info. The dam situation (no pun intended) didn't effect us since we lived in Orange Co. at the time.

I believe that they converted it to a cement dam after that little episode.

[capitan_refugio]

I looked up a few more facts concerning the Good Friday Earthquake of 1964 and the New Madrid quakes of Dec 1811 and Jan-Feb 1812.

The Richter magnitude (sometimes abbreviated Mr or Ml)is based on the seismic wave amplitude. Another newer measurement is the moment magnitude (Mw), which is proportional to the seismic moment (Mo). The Alaska quake had an Ml of 8.4, but an Mo of 9.2. The great size and energy release from this quake is attributed to the fact that hypocenter of the quake was related to the Aleutian subduction zone.

The New Madrid quakes predated instrumental measurements, but a comparison of reported damage to more recent quakes suggest they would rate in the 8.0 - 8.5 range. There is a very good history of these events entitled, "The New Madrid Earthquakes," by James L. Penick, Jr., History Professor at Loyola University of Chicago. It is/was available in paperback from the University of Missouri Press. Also, Otto Nuttli published "The Mississippi Valley Earthquakes of 1811-1812" in the US Geological Survey Earthquake Information Bulletin, 6:2 (1974).

By way of comparison, the 1906 San Francisco Earthquake had an estimated Ml of 7.7-7.9 (a downward revision of the old 8.25 number), and the 1857 Fort Tejon quake (between Los Angeles and Bakersfield) had an estimated Ml of 8.1-8.3. The 1857 quake is the model for much of the earthquake preparation in Southern Califonia. From contemporary accounts, the 1857 quake shook the southland for three to four minutes!

[hole_n_one]

Wasn't that fun!?!?!!

[Bernard Marx]

See #199 - no above-ground lines of any kind.

[SCalGal]

Re: Hearing Earthquakes

I lived in Reseda during the Northridge earthquake. It was very bad.... But I had a Akita puppy then, and after that we refered to her as the "Earthquake Alarm". She'd start barking at the ground, and you had just enough time to get under something. She never missed, very accurate. I don't know if she heard or felt them, but the alarm was great!