Some parts of the Bay Area are prone to an underexplored earthquake risk, according to a recent study led by U.S. Geological Survey scientists. In these places, quakes can produce long periods of shaking — something unaccounted for in existing building codes, but which can have devastating impacts.
“Prolonged shaking was very important in Northridge,” said Emily Brodsky, a professor of earth and planetary sciences at UC Santa Cruz, referring to a magnitude-6.7 earthquake that struck the Los Angeles area in 1994. The quake killed at least 57 people and damaged over 100,000 structures.
The authors of the new study analyzed ground motion records during 49 Bay Area earthquakes, occurring from 2001 to 2024. The quakes ranked in strength from magnitude 3 to magnitude 6. In total, the scientists probed about 7,400 ground measurements from seismometers across the region…