QUAKES NOT LINKED TO L.A.; EXPERTS SAY RECENT TEMBLORS ISOLATED.

Byline: Dominic Berbeo Staff Writer

The devastating magnitude-7.6 earthquake in Taiwan six weeks after a magnitude-7.4 shaker in Turkey were unrelated and have no bearing on whether Los Angeles gets hit with its own temblor, scientists said Tuesday.

The fact that two large quakes have struck in highly populated areas recently is just a ``cruel twist of fate,'' according to Susan Hough, a seismologist with the U.S. Geological Survey.

``But I wouldn't say there is a global trend going on here,'' she said.

The Taiwan earthquake was about 30 times more powerful than the deadly 6.7 Northridge Quake in 1994.

Scientists said Tuesday's quake was as powerful as the one that struck Turkey, but it was caused by different seismic motions.

The Turkey earthquake occurred along a strike-slip fault, similar to the San Andreas fault that runs beneath California. Quakes along those faults are caused by horizontal movement between plates deep in the crust of the earth.

The Taiwan quake occurred along a reverse-strike, or subduction fault. It occurs where two plates press against each other, and pressure from below pushes one plate up, while the other plate drops at a 45-degree angle.

Dominic Schezkel, a seismic analyst with the California Institute of Technology, said the fault affecting Taiwan, known as the Philippine plate, was being pushed upward by the neighboring Eurasian plate.

``The subduction zone is typical for some islands and places along the rim of the Pacific's `Ring of Fire,' '' he said. ``But although we're also in the `Ring of Fire,' we're an exception because our quakes are caused by lateral friction.''

He said Southern California gets an average of 200 magnitude-2.0 earthquakes each week, and there is no way to tell if a big one is near.

In short, he said, earthquakes remain a random phenomena, and the chances of finding the secret of prediction are little to none.