6.0 TEMBLER RATTLES `EARTHQUAKE CAPITAL'.

Byline: Kerry Cavanaugh Staff Writer

Right size. Right location. Just 16 years too late.

But the years-long delay didn't trouble earthquake scientists, who had their equipment in place Tuesday, when a 6.0-magnitude hit near Parkfield, a Central California hamlet known as the nation's earthquake capital.

At ground zero for earthquake study, dozens of sensors - seismometers, strainmeters, creepmeters - allowed researchers to monitor the moments before, during and after the temblor - information that might help unlock the mystery of predicting quakes.

``It's the most densely instrumented piece of ground probably on the planet,'' said Mike Blanpied, associate coordinator with the USGS earthquake-hazards program in Reston, Va.

``We will look very carefully to see if there was any hint that the Earth was giving us a clue that an earthquake might happen.''

The temblor hit at 10:15 a.m., followed in quick succession by more than 160 aftershocks, one with a preliminary 5.0 magnitude and four others at 4.1 or above. The initial, 10-second quake was felt along a 350-mile stretch, as far north as Sacramento and as far south as Santa Ana.

Kate Hutton, a seismologist at the California Institute of Technology in Pasadena, said there was a one-in-20 chance that Tuesday's quake was a foreshock to a larger quake that could hit within five days.

Parkfield - population 37 - sits on the juncture of the earth's Pacific and North American plates, a grinding 800-mile-long rupture zone better known as the San Andreas Fault.

The town was shaken by six 6.0 earthquakes between 1857 and 1966 - one approximately every 22 years. Because of the regularity, researchers predicted the town would have a similarly large quake in 1988 - or anytime between 1983 and 1993.

Researchers and reporters flocked to Parkfield hoping to understand the pattern and speculating that it might lead to predicting earthquakes elsewhere. But the window opened and closed with barely a rumble.

``When it didn't fall in that 10-year window, there was some disappointment that the Earth had fooled us again,'' said Thomas Jordan, director of the Southern California Earthquake Center and University of Southern California professor of earth sciences.

Some scientists speculated that Tuesday's quake was the one predicted to happen by 1993 - though a decade late.

``It was very much the anticipated earthquake, the anticipated magnitude and the anticipated section of the San Andreas Fault,'' Blanpied said. ``Of course, it was long overdue.''

Last December, a magnitude-6.5 earthquake jolted the Central California coast, killing two people in Paso Robles - the state's first fatal quake since the 6.7-magnitude temblor that hit the San Fernando Valley portion of Los Angeles in 1994.

Scientists hope to have even more information available to them when future quakes hit in Parkfield. This summer, geologists began drilling 2 miles beneath the surface, with plans to create an ``earthquake observatory'' that would be able to monitor the rocks, the stresses and the fault behavior during a temblor.

``This is earthquake country.' said Stephanie Hanna, a spokeswoman for the U.S. Geological Survey. ``We expect big earthquakes in this area, but don't know when they'll occur.''

The Associated Press contributed to this story.

Kerry Cavanaugh, [phone]

kerry.cavanaugh(at)dailynews.com

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6.0 quake epicenter

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