PubTalk 10/2006 — The Parkfield 2004 Earthquake

Lessons From the Best-Recorded Quake in History

by Andy Michael, Geophysicist

• To record high-quality measurements close to a large earthquake, the right instruments have to be in the right place at the right time
• Such a convergence happened, for the fi rst time ever, on September 28, 2004, when a magnitude 6 quake struck the San Andreas Fault near Parkfield, California
• The fault at Parkfield is monitored by a dense and diverse network of instruments designed to record events before, during, and after a quake (the Parkfield Earthquake Prediction Experiment)
• Parkfield was chosen for this experiment because a magnitude 6 earthquake had struck that area every two or three decades since at least 1857
• New data from the 2004 event provide important lessons about earthquake processes, prediction, and the hazards assessments that underlie building codes and mitigation policies