Quake Expedition Fails to Be Earth-Shaking Experience : Seismology: No promised temblors occur during a tour of the San Andreas Fault near Palmdale, but a small one hits close to Barstow.

It wasn’t John Alderson’s fault.

It was just that the crowd of earthquake enthusiasts he was leading on a quake-study expedition Saturday were in the wrong place to feel the temblor that registered magnitude 3.0.

They were hiking along the rugged San Andreas Fault at the edge of Palmdale--not along the eastern Mohave Desert fault located nine miles northwest of Barstow where the 10:28 a.m. shaker was centered.

Alderson is a Woodland Hills geologist who works for the Wilderness Institute. He was escorting 26 visitors on a daylong hunt for the odd leftovers from millions of years of activity along the world’s most notorious earthquake fault line.

“By the end of the day we’ll have an earthquake,” he had promised. “These days, that’s a pretty safe prediction to make.”

That was enough to put a smile on Matt Jalbert’s face.

“I take earthquakes seriously,” said the 26-year-old college geography student who lives in downtown Los Angeles. “But I love them. An earthquake certainly would be a highlight of the day.”

Let ‘er rip, agreed Lynn Rufrano, a homemaker from Seal Beach, as she stood on a bluff and looked down a 200-foot cliff into the heart of the 600-mile-long San Andreas Fault.

“I’ve got all the experts around me. And there’s not a thing here that’s going to fall on me,” she said. Laura Ellerby, a sales manager who lives in Marina del Rey, said: “When they’re happening, earthquakes are kind of exciting. . . .”

Officials of the nonprofit, Agoura-based Wilderness Institute said they have been offering $40-per-person San Andreas Fault tours for years. But Saturday’s was the first one that has ever sold out.

They were thanking last June’s 7.5-magnitude Lander’s quake for that. Not to mention last week’s report by scientists from the U.S. Geological Survey and the state Office of Emergency Services that warned that a magnitude 7 or greater earthquake will likely occur in the next few years on the San Andreas Fault close to San Bernardino or Palm Springs.

Alderson, 48, was joined by geologist Brent Miyazaki of Pasadena and paleontologist Bruce Lander of Altadena as he led the hikers up a hill where the fault crosses California 14 south of Palmdale.

The highway slices through the hill at that point. The road cut shows strips of sandstone and shale that were dramatically folded into U-shapes about 5 million years ago when the Earth’s Pacific Plate rubbed against its North American Plate, Alderson said.

A few miles away, the results of a more recent San Andreas quake--this one the Ft. Tejon temblor of 1857--showed distinctive earthen scarps, benches and linear troughs. The visitors were surprised to see new houses nearby.

“People need to be more aware of things like this,” Alderson said. “I certainly wouldn’t buy a house here. They’re asking for trouble building on this fault.”

The tour ended at Devil’s Punchbowl, a spectacular jumble of cliffs and rock outcroppings formed by San Andreas Fault movement as far back as 12 million years. The dark pink and tan rocks were set off by a four-inch layer of snow that dusted their tops.

Whittier accounting manager Bill Sanders said the trip had proved to him that the Earth is more powerful than occasional earthquakes demonstrate. His wife, Doreen, said: “I’m more concerned now than ever. And they’ve always scared me.”

As for Saturday’s Barstow quake, it was merely a mild aftershock of the Lander’s temblor, said Kate Hutton, a Caltech seismologist. It was so mild, she said, that experts did not bother to plot exactly which fault line it came from.

Unshaken, Alderson said his next quake expedition will be to Landers.