At 8:04 p.m. on Oct. 30, 2007, a magnitude 5.4 earthquake shook the Bay Area. The Alum Rock earthquake struck the Calaveras Fault in the hills northeast of San Jose, about 19 years ago this Friday.
The quake
The Berkeley Seismological Laboratory put its moment magnitude at 5.4 and located it about 8 km (5 miles) north-northeast of Alum Rock, roughly 9 km (6 miles) deep. Shaking was strong near the epicenter, and people filed felt reports from beyond Santa Rosa to the northwest, the Sierra to the east and King City to the south.
It was first announced as magnitude 5.6. The USGS revised the moment magnitude down to 5.4 on Nov. 6, 2007, according to its National Strong-Motion Project data page. The preliminary UC Berkeley solution placed it at 37.432 N, 121.776 W, at 9.2 km deep.
Why it still matters
The Calaveras Fault runs through the East Bay hills and the eastern Santa Clara Valley. The quake produced a large set of strong-motion recordings that the USGS made public for researchers.
The anniversary falls two weeks after this year's Great California ShakeOut drill. Emergency officials recommend that households keep water, food, medications and a flashlight for at least several days.