earthquake san francisco
Only one strong historical event , the 1843 Marked Tree, Ark., earthquake, and the 1811-12 New Madrid earthquakes have occurred in the New Madrid Seismic Zone.
Estimates of property loss and casualties are based on the expected type and distribution of damage for each postulated earthquake as determined by the size and location of the earthquake and the distribution and character of the buildings and structures within the affected area.
For the most probable catastrophic earthquake - a Richter magnitude 8+ earthquake similar to that of 1857, which occurred along the Southern San Andreas fault - estimates of fatalities range from about 3,000, if the earthquake were to occur at 2:30 a.m.
Many governmental units have generalized earthquake response plans, some have tailored earthquake plans, and several plans are regularly exercised.
Although current response plans are generally adequate for moderate earthquakes, Federal, State, and local officials agree that additional preparation is required to cope with a major earthquake.
For a catastrophic earthquake, current plans and preparedness are clearly inadequate, leading to a high likelihood that Federal, State, and local response activities would become disorganized and largely fail to perform effectively for an extended period of time.
The 1906 San Francisco earthquake was caused by a rupture on the San Andreas Fault. This fault runs the length of California from the Salton Sea in the south to Cape Mendocino to the north, a distance of about 800 miles .
Although the impact of the earthquake on San Francisco is perhaps most famous, the earthquake also inflicted considerable damage on several other cities. The earthquake caused severe damage throughout the San Francisco Bay Area, most notably in San Francisco and Oakland, but also in many other communities throughout the region, including Alameda, San Mateo, Santa Clara, San Benito County, Santa Cruz, and Monterey counties.
The quake killed 63 people throughout northern California, injured 3,757 people and left some 8,000 to 12,000 people homeless. The Loma Prieta earthquake, also known as the Quake of ‘89 and the World Series Quake, was a major earthquake that struck the San Francisco Bay Area of California on October 17, 1989 at 5:04 p.m. Caused by a slip along the San Andreas Fault, the earthquake lasted approximately 15 seconds and measured 6.9 on the moment magnitude scale .
The quake caused an estimated $6 billion to $13 billion in property damage, becoming one of the most expensive natural disasters in U.S. It was the largest earthquake to occur on the San Andreas Fault since the great 1906 San Francisco earthquake.
With the Bay Bridge closed due to damage, the Transbay Tube became the quickest way into San Francisco via Oakland for a time, and ridership increased by 90,000 in the week after the earthquake .
When the earthquake hit, Game 3 of the 1989 World Series baseball championship was just starting. Due to the unusual circumstance that both of the World Series teams were based in the affected area, many people had left work early or were staying late to participate in after-work group viewings and parties.
The Goodyear blimp, in San Francisco to cover the World Series, was the first blimp to be airborne over the location of a major earthquake.
The Loma Prieta earthquake irrevocably changed the San Francisco Bay Area’s transportation landscape.
The four oldest had been built in 1894; the five oldest had withstood the 1906 San Francisco earthquake. Embarcadero Freeway, State Route 480 : The earthquake forced the closure and demolition of San Francisco’s largely unloved Embarcadero Freeway ; this demolition opened up San Francisco’s Embarcadero waterfront to new development.
In the public’s mind, this earthquake is perhaps remembered most for the fire it spawned in San Francisco, giving it the somewhat misleading appellation of the “San Francisco earthquake”.
Areas situated in sediment-filled valleys sustained stronger shaking than nearby bedrock sites, and the strongest shaking occurred in areas where ground reclaimed from San Francisco Bay failed in the earthquake.
The great earthquake broke loose some 20 to 25 seconds later, with an epicenter near San Francisco.
On April 18, 1906, shortly after 5:00 a.m., a great earthquake struck San Francisco and a long narrow band of towns, villages, and countryside to the north-northwest and south-southeast.
On August 1, 1909, the California Senate enacted the California Standard Form of Fire Insurance Policy, which did not contain any earthquake clause.
The state decided that insurers would have to pay again if another earthquake was followed by fires. Other earthquake-endangered countries followed the California example.
The earthquake and resulting fire is remembered as one of the worst natural disasters in the history of the United States.
The death toll from the earthquake and resulting fire, estimated to be above 3,000, represents the greatest loss of life from a natural disaster in California’s history.
The city interim fire chief sent an urgent request to the Presidio, an Army post on the edge of the stricken city, for dynamite.
The total disregard to earthquake safety plagues the city today, as a majority of buildings standing in the city today were built in the first half of the 20th century.
Areas situated in sediment -filled valleys sustained stronger shaking than nearby bedrock sites, and the strongest shaking occurred in areas of Bay where landfill failed in the earthquake .
The Metropolitan Opera Company lost all of the sets and costumes it had brought to the earthquake and ensuing fires.
As damaging as the earthquake and its aftershocks were, the fires that burned out of control afterward were much more destructive. The immense power of the earthquake had destroyed almost all of the mansions on Nob Hill except for the Flood Mansion.
The earthquake caused ruptures visible on the surface for a length of 470 kilometers .
The earthquake was the worst single incident for the insurance industry before the September 11, 2001 attacks.
The earthquake ruptured the northern third of the fault for a distance of 296 miles .
The most widely accepted estimate for the magnitude of the earthquake is a moment magnitude of 7.8; however, other values have been proposed from 7.7 to as high as 8.3.
The USGS estimates that the earthquake measured a powerful 7.9 on the moment magnitude scale.
Widely previously interpreted as precursory activity to the 1906 earthquake, they have been found to have a strong seasonal pattern and were found to be due to large seasonal sediment loads in coastal bays that overlie faults as a result of the erosion caused by ” hydraulic mining ” in the later years of the California Gold Rush.
The USGS Earthquake Hazards Program issued a series of Internet documents, and the tourism industry promoted the 100th anniversary as well. Eleven survivors of the 1906 earthquake attended the centennial commemorations, including Irma Mae Weule, who was the oldest survivor of the quake at her death in 2008 at the age of 109.
The Great 1906 Earthquake and Fire from the Bancroft Library, includes interactive maps and panoramas.
After the 1906 earthquake, a global discussion arose concerning a legally flawless exclusion of the earthquake hazard from fire insurance contracts. It was constructed in 1875 primarily financed by Bank of California co-founder William Ralston, the “man who built San Francisco”.
Alice Eastwood, the Curator of Botany at the California Academy of Sciences in San Francisco, is credited with saving nearly 1,500 specimens, including the entire type specimen collection for a newly discovered and extremely rare species, before the remainder of the largest botanical collection in the western United States was consumed by fire.
The fire ultimately destroyed over 500 city blocks of the downtown core from Van Ness Avenue, a wide arterial thoroughfare that bisects the center of the city, to the docks on San Francisco Bay. Collaring a policeman, he sent word to Mayor Schmitz of his decision to assist, and then ordered Army troops from as far away as Angel Island to mobilize and come into the City.
The most recent analysis by the United States Geological Survey shows that the most likely epicenter was very near Mussel Rock on the coast of Daly City, an adjacent suburb just south of San Francisco.
Clutching an autographed photo of President Theodore Roosevelt, Caruso made an effort to get out of the city, first by boat and then by train, and vowed never to return to San Francisco. He kept his word.
One journalist at the time wrote that readers elsewhere should understand that it was not a fire in San Francisco, but rather a fire of San Francisco.
As fires raged through San Francisco, soldiers unload one of many civilian wagons pressed into service during the emergency.
Panorama of San Francisco in ruins from Lawrence Captive Airship, 2,000 feet above San Francisco Bay overlooking water front.
The shaking intensity as described on the Modified Mercalli intensity scale reached VIII in San Francisco and up to IX in areas to the north like Santa Rosa where destruction was almost complete.
In April 1906, the world’s greatest tenor, Enrico Caruso, and members of the Metropolitan Opera Company came to San Francisco to give a series of performances at the Tivoli Opera House. The night after Caruso’s performance in Carmen, the tenor was awakened in the early morning in his Palace Hotel suite by a strong jolt.
In the 1960s, a seismologist at UC Berkeley proposed that the epicenter was more likely offshore of San Francisco, to the northwest of the Golden Gate.
Gold transfers from European insurance companies to policyholders in San Francisco led to a rise in interest rates, subsequently to a lack of available loans and finally to the Knickerbocker Crisis of October 1907 and a recession of the U.S. .
San Francisco ” Oakland Bay Bridge, Interstate 80 : The Bay Bridge was repaired and reopened to traffic in just one month.
The San Francisco ” Oakland Bay Bridge suffered relatively minor damage, as a 50-foot section of the upper deck on the eastern side crashed onto the deck below.
One 50-foot section of the San Francisco ” Oakland Bay Bridge also collapsed, causing two cars to fall to the deck below, leading to the single fatality on the bridge.
Transbay Ferries : Ferry service between San Francisco and Oakland, which had ended decades before, was revived during the month-long closure of the Bay Bridge as an alternative to the overcrowded BART. Not only did the quake force seismic retrofitting of all San Francisco Bay Area bridges, it caused enough damage that some parts of the region’s freeway system had to be demolished.
Originally terminating at Franklin Street and Golden Gate Avenue near San Francisco’s Civic Center, the section past Fell Street was demolished first, then later the section between Mission and Fell Streets.
San Francisco’s fireboat was used to pump salt water from San Francisco Bay through hoses dragged through streets by citizen volunteers.
At the intersection of San Francisco’s Beach and Divisadero Streets, a gas main rupture caused a major structure fire.
Five people were killed near Fifth and Townsend in San Francisco as a brick facade collapsed onto the sidewalk and street.
Bay Area Rapid Transit : The BART rail system, which hauled commuters between the East Bay and San Francisco via the Transbay Tube, was virtually undamaged and only closed for post-earthquake inspection.
Cars on the upper deck were tossed around violently, some of them flipped sideways and some of them dangling at the edge of the highway.
Cypress Street Viaduct / Nimitz Freeway, Interstate 880 : The double-decked Cypress Street Viaduct, Interstate 880 was demolished soon after the earthquake, and was not rebuilt until July 1997.
The worst disaster of the earthquake was the collapse of the two level Cypress Section of Interstate 880 in West Oakland.
The highway was closed for several months until it could be demolished and rebuilt. Another section of Highway 1 through Monterey had to be rebuilt following the earthquake as well.
AFTER THE FALL: The earthquake shattered the Bay Area, but the cities hardest hit are now mostly rebuilt - and the scars are hidden deep below the surface.
31 buildings were ruined enough to warrant demolishing; seven of which had been listed in the Santa Cruz Historic Building Survey.
The earthquake also destroyed several buildings in the Old Town district of Salinas.
The pilots of the blimp reported that the blimp bounced during the quake almost as if it were on the ground, the first confirmation that the air column above an earthquake is affected by the movement of the ground underneath.
Because little attention had been paid to strengthening it in case of a major earthquake, the freeway was changed very little if at all from when it was built.
Private donations poured in to aid relief efforts and on October 26, President George H.W. Bush signed a $3.45 billion earthquake relief package for California.
Signal strengths 20 times higher than normal were observed on October 3, rising to 60 times normal about three hours before the earthquake.
The earthquake made it clear that the Bay Bridge, like many of California’s toll bridges, required major repair or replacement, for long-term viability and safety.
Fans reported that the stadium moved in an articulated manner as the earthquake wave passed through it, that the light standards swayed by many feet, and that the concrete upper deck windscreen moved in a wave-like manner over a distance of several feet.
Water from the bay was shot at the burning buildings by fireboats similar to those used to put out fires caused by the 1906 earthquake.
Subsequent analysis indicated that the damage was due to the amplification of the earthquake’s Seismic waves by waves reflecting off the deep ) discontinuities in the Earth’s surface.
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.
At almost precisely 5:12 a.m., local time, a foreshock occurred with sufficient force to be felt widely throughout the San Francisco Bay area.
Most of the fatalities occurred in San Francisco, and 189 were reported elsewhere.
