Marina District landfill and 1989 liquefaction

Much of the Marina District and adjacent shoreline was created with bay fill and dredged sand during the 1915 Panama-Pacific International Exposition and later developments. That reclaimed-ground foundation amplified shaking and produced widespread liquefaction and sand boils during the 1989 Loma Prieta earthquake, producing concentrated structural damage in the neighborhood. The phenomenon highlights how built fill and bay-margin geomorphology can produce locally severe seismic effects in San Francisco.