Loma_Earthquake

Loma Earthquake Loma Prieta Earthquake At 5:04 PM on October 17, 1989, the San Francisco Bay Area was severely shaken for 15 seconds by the Loma Prieta earthquake located to the south on the San Andreas fault near Santa Cruz. Although the quake did not tear the ground surface, it collapsed some buildings and freeway overpasses built upon the soft “bayfill” sediment in San Francisco and Oakland. A section of the Bay Bridge collapsed. The epicenter of the magnitude 7.1 quake was located about 10 miles northeast of Santa Cruz along a segment of the San Andreas fault, near Loma Prieta peak, the highest peak in the Santa Cruz Mountains. It was felt over an area of about 54,000 square miles. The rupture occurred on a 30-mile length of the San Andreas fault called the Santa Cruz Mountains segment. The focus was eleven and a half miles underground at a spot near China Ridge in Nisene Marks State Park. The land on the seaward side of the fault slipped five and a half feet northwest. The Loma Prieta quake was the largest earthquake to occur in the San Francisco Bay Area since 1906, and the largest, earthquake, san, prieta, loma, fault, area, several, santa, magnitude, cruz, andreas, side, section, rupture, quake, motion, francisco, earthquakes, collapsed, bay, about, surface, similar, probability, over, occurred, northeast, miles, ground, 1906, southwest, since, near, mountains