Harrolds.Blogspot.com
Southern California is 150 years overdue for quake like this.
repeat of a year ago TV article ...Chilling video simulates a 7.8 quake,
published by KABC-TV: November 12, 2008
| http://harrolds.blogspot.com/2010/01/re-58-shaker-in-valley.html The Imperial Valley has historically been one of the most seismically active areas in California. A 19th century example:
There have been 20th century earthquakes of M 6 or greater in 1915, 1940, and 1979, with the strongest, a M 6.7 quake that killed seven people, occurring in 1940. The geological forces that caused the November 23-24, 1987, 6.6 earthquakes are the same ones that pulled Baja California away from Mexico eons ago to form the Gulf of California. http://www.johnmartin.com/earthquakes/eqpapers/00000073.htm A friend said that he'd been in a briefing which discussed a scenario in which the "All American Canal" (what's left of the Red River) embankments & dams could rupture flooding the Imperial Valley. I worry that an earthquake that causes land to drop (like in Alaska some years ago) would happen in the area of Mexico that's SE of us about 20 miles or so. From what I've read, the Sea of Cortez (sea level) is only kept from flowing back into the Imperial Vally by roughly 5 feet of soil. I'd hate to imagine the Sea of Cortez gushing down toward us. My house would be 60+ feet under water! related: http://harrold.org/rfhextra/earthquake.html |
by Gene Gleeson [excerpts]article link: http://abclocal.go.com/kabc/video?id=6502481
ELYSIAN PARK, Calif. (KABC) [2008] -- Scientists painted a chilling picture of what a 7.8-magnitude earthquake would look like.
There are signs all around Southern California of past earthquakes, like the mountains that surround the Los Angeles basin, produced by big earthquakes in the past.
Southern California is on the eve of "The Big One," ..
What's coming is a 7.8 earthquake centered near the Salton Sea.
An earthquake that big would produce shaking 50 times stronger than the 1994 Northridge earthquake.
"We clearly understand, given the predictability and the magnitude of this earthquake, that public safety, the fire service, law enforcement, emergency medical services and government will be overwhelmed," said Chief Michael Freeman, L.A. County Fire Dept.
U.S. Geological Survey scientists have developed a video of the scenario. The red is the most violent shaking, exaggerated 1,000 times. Southern California is 150 years overdue for quake like this. "Landslides would be starting when they are subjected to the strongest shaking. Now we can see the S-wave, which is very intense in this particular area as the rupture hits us. There's the S-wave. Now the rupture is coming through at approximately 64 seconds. There you can see the offset across the fault as one side moves relative to the other approximately 12 feet, offsetting I-15," said Brad Aagaard, USGS research geophysicist, as he described the earthquake animation.
The epicenter may be 150 miles away [in the Imperial Valley], but shaking from a great earthquake would be severe throughout the region, as demonstrated in animations showing how the shock waves hit Ontario, Orange County and central Los Angeles.
"You'll notice that there's black areas; those correspond to areas that are undergoing very intense shaking, so even after areas reach a peak intensity in the red, the black areas continue to show what areas are subjected to strong shaking, even after reaching their peak intensity," said Aagaard.
- Quake animation: Southern California
- Quake animation: Buena Park
- Quake animation: Burbank
- Quake animation: Cajon Pass
- Quake animation: Corona
- Quake animation: Huntington Beach
- Quake animation: Lancaster
- Quake animation: Long Beach
- Quake animation: Los Angeles
- Quake animation: Marina del Rey
- Quake animation: Ontario
- Quake animation: Palm Springs
- Quake animation: Watts
- Quake animation: Woodland Hills
- Quake animation: Ventura
- USGS: More quake animations
Remember Hurricane Katrina? Officials here say "The Big One" would topple 1,500 buildings, start fires and kill and injure thousands.
"Part of the analysis we were actually trying to understand: what makes a natural disaster become a catastrophe? And we end up with a question: Well, it's going to depend on how much our social system can hold together," said Dr. Lucy Jones, USGS.
(Copyright ©2010 KABC-TV/DT. All Rights Reserved.)
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