PubTalk 8/2006 — Hidden Faults Under Silicon Valley

Do new discoveries change our view of Santa Clara Valley earthquake hazards?

by R. D. Catchings, Geophysicist 

• Seismic profiles have revealed the valley.s deep structure and previously unknown faults
• Earthquakes and seismic reflection images suggest some reverse faults beneath the valley that are not seen at the surface
• The disastrous 1994 Northridge earthquake occurred on a hidden fault like those now known to underlie Silicon Valley
• Deep sedimentary basins on both sides of the valley can greatly amplify earthquake shaking