Scientists have discovered that the San Andreas Fault in California continued to slip for up to 12 years after the magnitude 6 Parkfield earthquake that hit the state in 2004.

—

How long this movement lasts varies widely depending on the fault system. In a study published in the Bulletin of the Seismological Society of America, geophysicist James Lienkaemper from the U.S. Geological Survey and Forrest McFarland of San Francisco State University, have now analyzed the Parkfield earthquake to create better afterslip forecasts for parts of the fault expected to rupture.

The San Andreas Fault is one of the longest fault systems in the world, stretching around 800 miles (1,300 km) through California. …