Tremors on the San Andreas Fault

UC Berkeley seismologist Robert Nadeau reports on the observation of tremor on the San Andreas fault in the current issue of Science Express. Along with co-author David Dolenc, Dr. Nadeau reports on 3 years of data along a section of the San Andreas Fault near Cholame, CA, the inferred epicentral region of the 1857 Fort Tejon earthquake. Tremors are long-duration seismic signals with no clear P or S waves.

Nadeau and Dolenc note that these tremors occur at depths between 20 and 40 km, below the zone where earthquakes typically orginate. Their observations suggest that the rate of tremors may correlate with variations in local earthquake activity.

• Science Magazine
  • Abstract
  • PDF of the article
• Deep tremors under San Andreas fault could protend earthquakes - UC Berkeley Press Release
• Tremors rock earth deep beneath San Andreas Fault - puzzling vibrations baffle researchers from the San Francisco Chronicle