The epicenter was located on the San Andreas fault roughly 56 miles south of San Francisco in the Santa Cruz Mountains. It was originally introduced by the Italian seismologist Giuseppe Mercalli in 1902, and was modified and updated for "modern" building practices in 1931. The largest . The epicenter was located near Loma Prieta peak in the Santa Cruz Mountains, approximately 14 km (9 mi) northeast of Santa … Filtering the Data According to the Modified Mercalli scale earthquakes that are within the range of 4-4.9 magnitude are detectable by people outdoors and are strong enough to wake some people up at night. The most widely used scale is the Modified Mercalli Intensity Scale (MMI scale). The Cypress Structure in Oakland, California after it collapsed during the 1989 Loma Prieta earthquake. These intensities are compared with ground amplification in three frequency bands and with the intensities at the same sites from the 1906 San Francisco earthquake. This is why, in the 1989 Loma Prieta earthquake, the Marina district of San Francisco was one of the most damaged areas, though it was nearly 100 km from the epicenter. A plausible magnitude 7.8 earthquake on the San Andreas fault could bring widespread severe, violent and extreme shaking, as defined by the Modified Mercalli Intensity Scale, … The 1989 Loma Prieta earthquake occurred on California’s Central Coast on October 17 at 5:04 p.m. local time. ... ** Modified Mercalli intensity Scale (Wood and Neumann, 1931) Other areas affected by the same earthquake were assessed on the Mercalli scale to have an Intensity of VIII. The Loma Prieta earthquake is the latest in a series of destructive earthquakes that have rocked the San Francisco Bay area during historic times (Table 1). The Loma Prieta earthquake which occurred in California in 1989 was measured and estimated to have a maximum intensity of IX, meaning there was very violent shaking. Earthquake shaking is measured using the Modified Mercalli Intensity (MMI) Scale. ... Virginia, like most states on the eastern seaboard, has a moderate level of risk from earthquakes. Earthquake damage is quantified using estimates of the Modified Mercalli Intensity at the recording sites and safety tags issued by the City of San Francisco Building Department. The Modiﬁed Mercalli Intensity Scale is based on the ... San Francisco during the 1989 Loma Prieta earthquake (the World Series earthquake). The largest was a magnitude 4.0 earthquake in June 1989 that measured IV on the Modified Mercalli Intensity scale at Palco and did minor damage. ... That gave the Mercalli Scale, as well as the followed European MSK-64 scale, the quantitative element, which represents the vulnerability of the building's type. On October 17, 1989, at 5:04:15 p.m. (PDT), a magnitude 6.9 earthquake severely shook the San Francisco and Monterey Bay regions. Whereas the magnitude of an earthquake describes how much energy is released by an earthquake, calculated according to the length of a fault rupture and how far it slipped, the MMI scale describes the intensity of earthquake shaking at a specific location by considering its effects on people, objects and buildings.
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