2007 Alum Rock earthquake 2007 Alum Rock earthquake The 2007 Alum Rock earthquake occurred on in Alum Rock Park in San Jose, California. It measured 5.6 on the moment magnitude scale and had a maximum Mercalli intensity of VI ("Strong"). The event was then the largest in the San Francisco Bay Area since the 1989 Loma Prieta earthquake, which measured 6.9 on the moment magnitude scale, but was later surpassed by the 2014 South Napa earthquake. Ground shaking from the Alum Rock quake reached San Francisco and Oakland and other points further north. Sixty thousand felt reports existed far beyond Santa Rosa, as far
1989 Loma Prieta earthquake the earlier shock. Also in Los Gatos, one man died when he exited a building through a window and fell five stories. The Loma Prieta earthquake was named for Loma Prieta Peak in the Santa Cruz Mountains, which lies just to the east of the mainshock epicenter. 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