Locations of liquefaction features produced during the 1989 Loma Prieta earthquake. Liquefaction features are mapped as points, scattered along lines or distributed within larger areas. Many of the liquefaction sites formed in areas of fill that has been placed where there was once Bay or marsh. For example, ground deformation from liquefaction in the Marina District of San Francisco damaged water mains, reducing the supply of water to fight fires. Some pipelines ruptured at the same locations of liquefaction and damage as those during the 1906 earthquake (O'Rourke and others, 1992). Liquefaction caused considerable damage in this part of the Bay Area during the 1989 earthquake, despite the relatively low levels of shaking from the earthquake source located in the Santa Cruz Mountains approximately 100 km from downtown San Francisco

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