Earthquake Forecast Underscored in Study

A new study supports an earlier prediction that an earthquake capable of causing considerable damage will hit near Parkfield, Calif., about 1988, government geologists said.

Paul Segall of the U.S. Geological Survey at Menlo Park said the new study, based on the lack of movement along a portion of the San Andreas Fault, indicates the quake most likely will hit Parkfield any time between now and 1989.

That area’s most recent significant temblor, registering 5.5 on the Richter scale, occurred June 27, 1966; there were comparable quakes near Parkfield in 1934, 1922, 1901, 1881 and 1857, according to Segall.

Parkfield is a sparsely populated ranching community roughly midway between Los Angeles and San Francisco. Based on the earthquake history of the region, indicating a rough 22-year interval between temblors, another federal research team two years ago had predicted that a quake up to a magnitude 6 would hit within five years of 1988.