Calaveras Fault 6.5 that occurred in 1911 in the Morgan Hill area. The most recent of these was a magnitude 6.2 earthquake near Morgan Hill in 1984. A magnitude 5.6 earthquake occurred on the Calaveras Fault on October 30, 2007 at 20:04 PDT (October 31, at 03:04 UTC), near Alum Rock. Prior to the 2014 South Napa earthquake, it was the most powerful quake to hit the Bay Area since the Loma Prieta earthquake of 1989, and the largest on the Calaveras Fault since 1984. Although it has been known for some time that the Calaveras and Hayward faults merge in the
1989 Loma Prieta earthquake 1989, shock, in anticipation of an upcoming large earthquake, staff at the University of California, Santa Cruz deployed four accelerometers in the area, which were positioned at the UCSC campus, two residences in Santa Cruz, and a home in Los Gatos. Unlike other nearby (high gain) seismographs that were overwhelmed (driven off scale) by the large magnitude mainshock, the four accelerometers captured a useful record of the main event and more than half an hour of the early aftershock activity. The June 27, 1988, shock occurred with a maximum intensity of VI ("Strong"). Its effects included broken windows in Los