San Andreas : California Spectacular--to a Fault
It is the most studied, most scrutinized, most publicized earthquake fault in the world. For millions of years it has followed an alternating pattern of long periods of relative quietude and then sudden, monumental destruction.
The San Andreas Fault. Like a giant, sinuous scar running through the state, it divides and it defines California. Without the San Andreas and its ancillary faults, California would be devoid of its most characteristic landscapes, geologists say, and probably would bear a resemblance to Kansas. But the ancient geological movement alongside the fault has created California’s spectacular geography--the jagged seascapes, coastal mountain ranges and sweeping valleys.
Symbol of the State
The San Andreas is so synonymous with California, so intertwined with the mythology of the state, that to many non-residents it somehow symbolizes the region. A place where people are willing to live with risks. A place where idyllic, subtropical landscapes are teetering on the edge of disaster. A place apart--divided and separated from the rest of the country by the 800-mile-long fault.
The San Andreas encompasses so much prime territory that Californians have learned to coexist with the fault. Thousands of people live directly on or beside the San Andreas and it has been incorporated into the life style of the region.
You can ride a motorcycle alongside the fault at a recreational vehicle park in San Benito County. You can drink beer at a San Juan Bautista restaurant called the Faultline and study the fissure-ridden landscape.
You can buy a T-shirt in Hollister that boasts: “Earthquake Capital of the World.” You can take an earthquake tour at Point Reyes National Seashore and study the spot where, according to local legend, Matilda the cow was swallowed up in the 1906 quake, leaving only her tail waving in the wind.
But while many blithely reside beside the San Andreas, ignoring its potential for danger, scientists are busy studying geological evidence of past destruction and predicting a major quake with enormous damage.
Geologists expect a major earthquake--perhaps one as strong as 8.5 on the Richter scale--along the San Andreas’ southern section within the next 50 years. Such a quake could kill thousands of people and cause billions of dollars in property damage.
“That section hasn’t broken in more than a hundred years so a few generations can live and die without being bothered,” said Caltech geophysicist Kerry Sieh, a prominent earthquake researcher. “Yes, people have a tendency to get blase about it. But after a major quake I can tell you this: It will take a long while before people become blase again.”
The San Andreas, which knifes through so much magnificent California scenery, begins inauspiciously beneath the brackish waters of the Salton Sea. Traces bisect Bombay Beach, the southernmost community in the fault zone.
The evocative name of Bombay Beach is more glamorous than the reality. An aluminum ghetto with dirt sidewalks, Bombay Beach is composed almost entirely of aging trailers and mobile homes with silver foil pasted to the windows to shut out the desert sun. The population, according to the Bombay Beach fire chief, is 3,000 in the winter and 300 in the summer.
The only open business in this desolate area on a windy afternoon is the Ski Inn, a small stucco bar and restaurant with a few booths and a pool table. As a result of the fault and unstable ground, there is an enormous crack running behind the full length of the bar. A few locals distractedly discussed the San Andreas’ effect on their community.
“Sure I’m worried,” said one man sarcastically, ordering another in a series of gin and tonics. “That’s why I’m drinking.”
A few miles east of Bombay Beach are the first visible signs of the fault. But the signs are so subtle, only someone with geological training can spot them. Small streams twisted and offset by countless earthquakes are the most visible evidence of the fault.
The Earth’s crust is broken into a series of “plates” that have been slowly moving for millions of years, said Robert Wallace, a chief scientist for the U.S. Geological Survey. Two plates--the Pacific and North American--meet in California and the boundary between them is the San Andreas, the master fault of a vast fault network that slices through the length of the state.
The Pacific plate is moving north at a rate of about two inches a year. And in about 10 million years, to the chagrin of Bay Area chauvinists, the western edge of Southern California will have drifted far enough north so that San Francisco will be a suburb of Los Angeles, geologists say.
There are grooves and troughs over sections of the San Andreas that can be spotted by the untrained eye from the air. But there is no continuous rift that windshield geologists can point to while driving by. Most people could break a toe on the San Andreas and never know it was there.
The San Andreas cuts northwest from the Salton Sea, passing the outskirts of Indio and Palm Springs, through the area north of Banning and skirting San Bernardino. In the desert, among the signs of the San Andreas are occasional lines of palms and oases in the harsh, barren landscape.
Often crushed rock along the fault zone turns to clay and forms an impenetrable barrier to underground water channels, said George Meyer, a geology professor at College of the Desert. The water has nowhere to go and eventually bubbles up to form springs and oases.
Many Indian trails in the desert run alongside the San Andreas, where water sources are plentiful, said Katherine Sauvel, who operates the museum at the Morongo Indian Reservation near Banning. The San Andreas cuts directly through the reservation.
“We believe the Earth is alive and when people don’t respect it and destroy things and hunt without any regard to tradition, then Mother Earth shows her displeasure,” said Sauvel, a Cahuilla Indian who was reared on a reservation. “So she gives us earthquakes.”
Sauvel, 66, was living on the reservation in 1933 when she experienced her first big quake. It knocked her to the ground and she saw the giant palms sway almost to the breaking point.
“The shamans gathered the people and they met the next day in the ceremonial house,” Sauvel recalled. “The shamans wore feather headdresses and carried two owl feathers. They gathered the people together to tell them they were not living right. Then all night they danced and prayed to purify what was done wrong.”
A series of tract homes on Hill Drive in the foothills of San Bernardino lie directly above the San Andreas. Kelly Richardson, 20, lives with her parents on Hill Drive and wants to move out. She pointed out a large fault-induced crack that runs though the linoleum in the front hall.
“I’m looking for a place away from this neighborhood, as far from the fault as I can get,” said Richardson, whose parents decided that the price for earthquake insurance was too high. “Living near it wouldn’t be so bad, but right on it. . . . I’ve had nightmares of the earth opening up and our house being sucked into the ground.”
As a result of laws passed in 1972, developers can no longer build over traces of active faults. Structures right on the fault undergo more severe shaking during a quake and face the danger of rupturing, said Sieh of Caltech.
From San Bernardino, the San Andreas heads northwest through the snow-flecked San Gabriel Mountains and bisects the 56 acres at St. Andrew’s Priory, a Benedictine retreat.
Father Philip hiked up a trail, sandals slapping, his long black robe billowing in the wind. It was early spring, a crystalline clear afternoon with a hint of coolness in the high desert air. When he reached the top of a peak, overlooking a small valley of cherry trees and hillsides blooming with violet wildflowers, he pointed out the subtle signs of the fault.
“We take precautions; we built with reinforcements,” Father Philip said. “And we trust . . . in God and in fate.”
One of the reasons the priory chose the name St. Andrew’s, he said, was because of the fault. (The fault was named after a lake in San Mateo called San Andreas--St. Andrew in Spanish--by geologist Andrew Lawson.) Father Philip derives comfort, he said, from his certainty that St. Andrew will intercede and offer the priory some special protection in the event of a great quake.
The fault continues northwest to Palmdale, beneath the swimming pool at the Caravan Inn in Gorman and through the Unocal gas station on Mount Pinos Road in Maricopa. Then it crosses the Carrizo Plain, an arid valley 50 miles west of Bakersfield, which is considered the best place to view the fault, especially from the air. Long troughs beside escarpments and streams altered by earthquakes and plate movement are easily visible.
To the north, the tiny town of Parkfield, at the edge of an isolated valley, is an unlikely center of attention. But Parkfield is famous among geologists because the section of the San Andreas that runs through the town is the most punctual earthquake fault in the world. For more than a century the fault has ruptured in Parkfield with an earthquake of 5.5 to 6 magnitude about once every 22 years. The last one was in June, 1966.
Now the Parkfield area is the most intensely scrutinized section of the San Andreas, the U.S. Geological Survey said. There are more than 100 different creep meters, seismographs, strain tests and other experiments near the town. And dozens of researchers periodically stop by Parkfield to study the fault.
Handful of Residents
Parkfield is so small that when Duane Hamann, a teacher at the local school who also works part time for the U.S. Geological Survey, was asked how many people live there, he counted every resident on his fingers and came up with the number 23. After scientists recently established Parkfield’s quake cycle, the town was deluged by geologists and then reporters and camera crews.
One resident groused to reporters that the geologists were more trouble than the earthquakes. Reporters were not very popular either. One camera crew showed up at the quaint white schoolhouse, expecting students to enthusiastically run through an impromptu earthquake drill for the big city news team. But when the crew arrived, Hamann said, they were confronted with a large sign that a sixth-grader had taped to the door: “We’ve had enough for one day.”
They were the third news team to show up that day.
Not all residents are put off by the sudden attention. Donalee Thomason, 61, proudly proclaimed that she was on television seven times last year and was interviewed by nine newspaper reporters. She added, slightly miffed, that she was supposed to be on the “Today” show but was bumped at the last minute.
Uses the Jargon
Thomason, who has lived her whole life in Parkfield and whose childhood home lost four chimneys in earthquakes, enjoys talking to geologists and frequently tosses out such terminology as “S waves,” “rift trench,” and “strike slip movement.”
“We’re isolated here and we don’t get that much contact with the outside world,” said Thomason, who has wired her clocks to the wall to keep them in place during a quake, placed latches on her cabinets, applied sticky wax to the bottom of her antiques for stability and purchased earthquake insurance. “This is the most exciting thing to happen to this town since I don’t know when.”
The small mission town of San Juan Bautista, northeast of Salinas, had planned to parlay its location on the San Andreas into a major tourist attraction. Rebecca McGovern, the head of the Chamber of Commerce, began organizing an earthquake festival several years ago.
She had planned to have the festival on rodeo grounds, directly over the San Andreas, and feature booths manned by earthquake researchers and a tour of the town showing assorted quake damage. McGovern was going to ask the San Jose professional soccer team, the Earthquakes, to make a guest appearance. And she had planned to show the melodramatic 1936 movie “San Francisco,” which featured Jeanette MacDonald surveying the damage of the 1906 quake at the end of the film and singing “The Battle Hymn of the Republic” along with the title song.
“Some developers from Hollister thought the festival would be bad for business so they put some undo pressure on people and got the thing canceled,” McGovern said. “They don’t like the reputation this area has for being an earthquake capital.”
But earthquakes always have been a tourist attraction in San Juan Bautista, McGovern said. The Faultline restaurant opened seven years ago and the previous owner named drinks after earthquake faults and offered free meals to anybody in the restaurant during a quake that reached at least 3 on the Richter scale.
Examples of Damage
Nearby Hollister, which is at the confluence of several ancillary faults of the San Andreas, has dramatic examples of fault damage. Earthquakes and gradual plate movement have caused curbs to split and shift, fences to bend and sidewalks to wind sinuously for blocks. Most of the liquor stores in town have incurred losses during quakes and now have wires or metal rods across their shelves.
At the Hollister Hills State Vehicular Recreation Area, motorcyclists crisscross the San Andreas on off-road bikes. Most riders are too macho to worry about earthquakes, said Larry Helm, a superintendent of the park. And the fault, he said, actually makes it a more desirable place to ride.
Because the plates have been moving for millions of years, there are radically different types of rock on either sides of the fault. As a result, the riders have the opportunity of experimenting on different surfaces.
On one side of the fault the soil is a dark adobe clay and on the other side it is a lighter granite. The riders slide and “hot dog” on the slick clay, Helm said. And on granite they can build up speed because the traction is better.
After passing through the Santa Cruz Mountains and then dipping down through Redwood City and Burlingame, the San Andreas cuts under Daly City, where the stereotypical California earthquake prophecy is actually taking place. Sections of the city are falling into the ocean.
Northwestern Daly City is probably in the most precarious position of any community on the fault line. Hundreds of homes are located in a “geological hazard study zone,” said Earl Hart, a program manager for the state fault evaluation and zoning program.
And houses in the 800 and 900 blocks of Skyline Drive were built in the early 1960s on what geologists now call “Landslide Site 26,” an unstable oceanfront cliff bisected by the San Andreas. The cliffs are crumbling into the ocean.
Two homes were condemned on Skyline Drive, there are five for-sale signs in the two-block area and property values continue to drop. Cynthia Zielenski bought a home on Skyline in 1962 and over the years watched about 100 feet of her backyard slowly crumble away. She lost her entire investment when she was forced to move her home, buy property in a nearby city and abandon the ravaged Daly City lot.
Forces of Nature
“More extensive studies should have been done, damn it, before they built these homes,” she said angrily. “The laws have been changed, but it doesn’t do us much good. Every time there was a big rainstorm, we lost part of the cliff in back. Every time there was a quake, I was afraid to look out the window--I didn’t know what would be left.”
From the deteriorating cliffs of Daly City, the San Andreas heads out to the Pacific, bypasses San Francisco, then cuts inland through Marin County. The self-guided earthquake tour at Point Reyes National Seashore shows dramatic evidence of the great 1906 quake--a 400-yard line on a hillside where the earth ruptured, a fence that was offset 16 feet and the spot where Matilda the cow supposedly was swallowed up. A local farmer told the apocryphal tale to a gullible federal geologist shortly after the quake, a park ranger said, and it was believed for many years.
North of Point Reyes, the fault winds through the redwood trees along the wild Sonoma and Mendocino coasts before heading west, through the mouth of Alder Creek at Manchester State Beach and out to sea. It parallels the coast and then, about 800 miles from its source in the desert, the great San Andreas intersects with another fault zone and disappears into the Pacific.
SAN ANDREAS FAULT The Earth’s crust is broken into a series of plates that have been slowly moving for millions of years, leaving differing geologies on each side. Two plates--the Pacific and North American--meet in California; the boundary is the San Andreas Fault. The Pacific plate is moving north at a rate of about two inches a year. It is violent, sudden movement that can release the enormous energy of an earthquake. At right is an aerial view of the fault near Taft, one of the areas where the fault line is best visible from the air.