CALIFORNIA IN BRIEF : PARKFIELD : Quake Expected Within 2 Years

Scientists say the long-awaited Parkfield earthquake should hit Central California sometime within the next two years, most likely around March, 1991. Parkfield, which straddles the San Andreas Fault east of San Luis Obispo, has had moderate quakes about every 22 years, and the area has been heavily instrumented by scientists who hope to learn much about what happens before, during and after a temblor. The last quake hit in 1966. The quakes usually have a magnitude of about 5.5 and do little damage in the rural area. In today’s issue of the British journal Nature, scientists with the University of Colorado, the U.S. Geological Survey and the National Oceanic and Atmospheric Administration report that the Parkfield area has been seismically quiet for some time now, suggesting that the fault may be storing its energy in preparation for the large quake.