Reminiscent of the earthquakethe earth shook, like a table bumped, causing a house of cards to fall.
California earthquake forecast and Earthquake prediction Since many forecasts had been presented for the region near Loma Prieta, seismologists were not taken by surprise by the October event. Between and there were 20 widely varying forecasts that were announced, with some that were highly specific, covering multiple aspects of an event, while others were less complete and vague.
An updated forecast was presented inat which time Lindh took the opportunity to assign a new name to the San Juan Bautista segment — the Loma Prieta segment.
Following each event, the State office of Emergency Services issued for the first time in Bay Area history short term advisories for a possible large earthquake, which meant there was "a slightly increased likelihood of an M6.
Following the August 8,shock, in anticipation of an upcoming large earthquake, staff at the University of California, Santa Cruz deployed four accelerometers in the area, which were positioned at the UCSC campus, two residences in Santa Cruz, and a home in Los Gatos. Unlike other nearby high gain seismographs that were overwhelmed driven off scale by the large magnitude mainshock, the four accelerometers captured a useful record of the main event and more than half an hour of the early aftershock activity.
Its effects included broken windows in Los Gatos, and other light damage in Holy Citywhere increased flow was observed at a water well.
Farther away from the Santa Cruz Mountains, pieces of concrete fell from a parking structure at the Sunnyvale Town Centera two-level shopping mall in Santa Clara County.
Other damage included cracked walls and foundations and broken underground pipes. At the office of the Los Gatos City Manager, a window that was cracked had also been broken in the earlier shock. Also in Los Gatos, one man died when he exited a building through a window and fell five stories.
The duration of the heaviest shaking in the Santa Cruz Mountains was about 15 seconds, but strong ground motion recordings revealed that the duration of shaking was not uniform throughout the affected area due to different types and thicknesses of soil.
At sites with rocky terrain, the duration was shorter and the shaking was much less intense, and at locations with unconsolidated soil like the Marina District or the Cypress Street Viaduct the intensity of the shaking was more severe and lasted longer.
The strong motion records also allowed for the causative fault to be determined — the rupture was related to the San Andreas Fault System. Because the rupture took place bilaterally, the duration of strong shaking was about half of what it would have been had it ruptured in one direction only.
The duration of a typical M6. Near Loma Prieta, the rupture was more shallow, had more strike-slip, and occurred on a fault that was near vertical. Because much of the slip in occurred at depth and the rupture propagated up dip, Beroza proposed that the overlying San Andreas Fault actually inhibited further rupture and also maintains that the occurrence of an event at the location that was forecast by the WGCEP in was coincidental.
The significant amount of vertical displacement in was a key aspect to consider because a long-term sequence of type events with an 80—year recurrence interval normally result in regions with high topographic reliefwhich is not seen in the Santa Cruz Mountains.
Three scenarios were presented that might explain this disparity. The first is that the geometry of the San Andreas Fault goes through a transition every several thousand years.
Secondly, slip type could vary from event to event. And lastly, the event did not occur on the San Andreas Fault. The majority of landslides occurred to the southwest of the epicenter, especially along road cuts in the Santa Cruz Mountains and in the Summit Road area, but also along the bluffs of the Pacific Coast, and as far north as the Marin Peninsula.
Highway 17 was blocked for several weeks due to a large slide and one person was killed by a rockfall along the coast. Other areas with certain soil conditions were susceptible to site amplification due to the effects of liquefactionespecially near the shore of San Francisco Bay where its effects were severe in the Marina District and to the west of the epicenter near rivers and other bodies of water.Faultine: Seismic Science at the Epicenter is made possible through the generosity of The Gordon and Betty Moore Foundation and the Jim Clark Endowment for Internet Education.
The Loma Prieta earthquake The Loma Prieta earthquake struck on October 17, , at p.m. Game 3 was scheduled to start at p.m. at Candlestick Park in San Francisco, and thousands of people were already .
Sep 21, · Watch video · Loma Prieta earthquake strikes near San Francisco. An earthquake hits the San Francisco Bay Area on this day in , killing 67 people and causing more than $5 billion in damages.
San Francisco–Oakland earthquake Map of the San Francisco–Oakland earthquake (also known as the Loma Prieta earthquake).
The quake struck with a moment magnitude of on October 17, just before the start of the third game of the World Series, which was being held at San Francisco's Candlestick Park.
Jan 06, · Several videos from Loma Prieta earthquake. This feature is not available right now. Please try again later.
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