Anniversary of the Great Quake Apr 18th

[Amelia]

[]http://images.livescience.com/images/ig14_earthquake_01.jpg[/]

A City Torn Apart

The California earthquake of April 18, 1906 ranks as one of the most significant earthquakes of all time. It measured a magnitude of 7.8. Shaking damage was equally severe in many other places along the fault rupture. The frequently quoted value of 700 deaths caused by the earthquake and fire is now believed to underestimate the total loss of life by a factor of 3 or 4. Most of the fatalities occurred in San Francisco, and 189 were reported elsewhere.

The 1906 San Francisco earthquake was so powerful and pervasive that it damaged buildings in Ferndale, a small town 200 miles to the north in Humboldt County. It was felt in Los Angeles, 400 miles to the south.

As the 100th anniversary of the event approaches—April 18—the geologists want to remind people of the risks associated with the next Big One.

"We want to emphasize that a large earthquake such as 1906 is not just a San Francisco quake, but a Northern California earthquake," said Brad Aagaard, geophysicist at the U.S. Geological Survey who led the effort. "Earthquakes greater than magnitude 7 are going to cause intense shaking over a large area — everyone needs to be prepared."

The 1906 quake killed more than 3,000 people. Damage exceeded $400 million, much of it due to fires. But the shaking was incredible.

"For the new fault rupture model, we re-analyzed century-old surveying and seismographic data," said Seok Goo Song, a geophysics graduate student at Stanford University. "Our model confirms the rupture was about 300 miles long with a magnitude of 7.8-7.9. Our work gives new insights into the strength of strong ground shaking in large earthquakes."

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Click here for Images from the San Francisco Chronicle, April 22, 1906 and the San Francisco Examiner, April 26, 1906

http://www.rootsweb.com/~usgenweb/ca/earthquake/earthquake.html

Thumbnail Archive of images of quake damage http://www.eas.slu.edu/Earthquake_Center/1906EQ/1906thumb.html

[CyberGuy]

My Great Grandfather on my dads side lived in Oakland at the time of this quake. He operated as an assistant on the only ferry from San Francisco to Oakland. When the great San Franscisco fire broke out after the quake the only escape for thousands of people was the ferry. My Great Grandfather worked for two days straight helping to ferry people out of San Francisco to the relative safety of Oakland. This with the fire bearing down on the ferry landing. When he did come home to his wife who did not know if he was alive or dead he just collapsed from exhuastion and slept for 24 hour straight.

[CyberGuy]

Next Big Quake? Maybe East of Bay Area

By SCOTT LINDLAW

HAYWARD, Calif. (AP) - New cracks appear in Elke DeMuynck's ceiling every few weeks, zigzagging across her living room, creeping toward the fireplace, veering down the wall. Month after month, year after year, she patches, paints and waits.

``It definitely lets you know your house is constantly shifting,'' DeMuynck said. So do the gate outside that swings uselessly 2 1/2 inches from its latch, the strange bulges in the street and the geology students who make pilgrimages to her cul-de-sac.

DeMuynck could throw her paint brush from her front stoop and hit the Hayward Fault, which geologists consider the most dangerous in the San Francisco Bay Area, if not the nation. Like others who live here, she gets by on a blend of denial, hope and humor.

It's the geologists, emergency planners and historians who seem to do most of the worrying, even in this year of heightened earthquake awareness for the 100th anniversary of San Francisco's Great Quake of April 18, 1906.

Several faults lurk beneath this region, including the San Andreas Fault on the west side of the Bay area, but geologists say the parallel Hayward on the Bay's east side is the most likely to snap next.

``It is locked and loaded and ready to fire at any time,'' said U.S. Geological Survey seismologist Tom Brocher.

The Hayward Fault runs through one of the country's most densely populated areas; experts say 2 million people live close enough to be strongly shaken by a big quake.

It slices the earth's crust along a 50-mile swath of suburbia east of San Francisco, from exclusive hilltop manors overlooking the bay to Hayward's humble flatlands. It snakes beneath highway bridges, strip malls, nursing facilities and retirement centers, and it splits the uprights of the football stadium at the University of California, Berkeley.

``A lot of these structures are going to come down,'' said David P. Schwartz, chief of the USGS's Bay Area Earthquake Hazards Project. He spoke with one foot on either side of the fault, marked by a crack that snaked through a parking lot in Hayward's business district.

Before San Francisco's Great Quake of 1906, on the San Andreas fault, there was the Great Quake of 1868 on the Hayward, a magnitude 6.9 rumbler that killed five people. Severe quakes have happened on the Hayward Fault every 151 years, give or take 23 years, meaning it is now into the danger zone.

Experts forecast the next big one will be in the potentially lethal 6.7 to 7.0 range. The Association of Bay Area Governments estimates it would wipe out some 155,000 housing units, 37,000 in San Francisco alone.

The ground on each side of the fault could shift 3 feet, meaning two objects on opposite sides could be abruptly carried a total of 6 feet apart, Schwartz said.

The Hayward Fault runs directly beneath Eden Jewelry and Loan, but the men working in the pawn shop shrugged when asked if they fear a quake.

``Honestly, it's a non-issue,'' said Saul Gevertz, 64.

The building was renovated about five years ago and now is essentially an enormous steel cage, designed to flex in an earthquake without breaking, said one of the building's co-owners, Darrell Davidson.

``I'm not worried-worried. I've thought about it,'' said Davidson, 47. ``I think we're in good shape. I hope to God we are.''

Nickey Avila acknowledged some alarm when informed that the fractures in the pavement outside his house were caused by the fault.

``I'm thinking one day it's going to move, but if I survive it, I'll be able to say I survived one of the biggest quakes of all time,'' said Avila, 23.

The quake could come at any moment.

``If it moved while we were walking, it wouldn't surprise me,'' Schwartz said during a tour of Hayward's misaligned street curbs, warped concrete gutters and abandoned buildings. They include the former Hayward City Hall, deemed too dangerous to occupy because it's right on the fault.

The City Hall was built in 1930, during an unusually quake-free period after the Great Quake of 1906 released stress on all faults in the region.

A ``virtual tour'' developed by the USGS shows the Hayward Fault slashing through identifiable structures, like DeMuynck's house, but she is resolved not to worry.

``There's dangers all around us, all the time, so if we thought about those dangers all the time, we wouldn't have anything else to think about,'' said DeMuynck, 62. ``We just come home and say, 'The house is still here.' We're OK for another day.''