Southland: a Place Waiting for a Quake : Odds Are Increasing That L.A. Area Will Be Hit by a ‘Monster’

Southern Californians are living at the edge of the fault line--and maybe on the edge of disaster.

No longer are earthquake watchers talking about the probability of a “big one” permanently disfiguring this megalopolis of more than 12 million residents.

They are talking only about how soon.

Each year, about 15,000 earthquakes are recorded in California. Few amount to more than a nerve-jolting rattle and roll.

But it is the “monster” quake that has long been a part of California’s mythology--always there, always approaching, always the unseen evil lurking along the 600-mile-long San Andreas Fault. The southern third of the jagged line lies about 70 miles southeast of America’s second-largest city.

Rendezvous With Upheaval

Like weathermen tracking a monster hurricane, scientists are reciting shorter and shorter odds for catastrophe in Southern California. The time frames differ widely, but they all add up to an expected rendezvous with upheaval.

“Within the next 20 years, the chances of a 6.5 to 8.3 quake are probably 90%. It’s inevitable,” said California Institute of Technology geologist Kerry Sieh. “And, the chances are 2% to 5% for a great quake of a San Francisco magnitude occurring this year.”

Further, a study by Japanese seismologist Kiyoo Mogi suggested there is a 50% chance that Southern California will be ravaged by an 8.3 quake--considered by seismologists as the ultimate jolt--in the next 30 years.

45% Error Factor

Given the built-in error factor, considered to be about 45%, it could happen tomorrow or in 50 years.

Every increase of one point on the Richter scale means the ground motion is 10 times greater. The difference between a 6.0 and an 8.0 quake is enormous.

Recent studies by the U.S. Geological Survey indicate that people who live near Los Angeles have much more to worry about than those in San Francisco and northward.

The study showed that there is roughly a 25% chance of a great earthquake occurring within 20 to 25 years in Southern California while there is a “very low” probability for Northern California.

“You see, the conventional wisdom is that it’s Southern California’s turn,” said Paul Jennings, chairman of the engineering and applied science department at Caltech. “There’s the feeling that they (Northern California) had theirs in 1906 (the San Francisco quake) and we had our big one in 1857,” the so-called Fort Tejon quake, which measured an estimated 8.3 and ruptured a 200-mile-long swath along the southern tier of the San Andreas Fault.

“A repeat of the 1906 quake is considered unlikely (in Northern California),” said Lynn Sykes, a geophysicist at Lamont-Doherty Geological Observatory at Columbia University, “mainly because so much more time has passed since Southern California got hit with that 8.3 (in 1857). They’re overdue.”

Estimated 14,000 Deaths

A 1981 Federal Emergency Management Agency study personalized the impending disaster, saying if an 8.3 tremor on the southern San Andreas hammered Southern California on a weekday afternoon, as many as 14,000 people would die--twice as many as who perished in last month’s calamitous 8.1 quake in Mexico City.

A 1981 U.S. Geological Survey study placed the death toll at 21,000 and estimated that property losses would run as high as $20 billion.

For three days, the Federal Emergency Management Agency study predicted, telephone systems would be only 25% effective. Two of the three major water aqueducts would be out of commission for up to six months.

Sewage would pour into the streets, polluting rivers, harbors and beaches, because of broken sewer lines and damaged treatment plants.

It is not just the San Andreas Fault--by far the most studied fissure in the nation--that concerns seismologists.

There is a network of lesser faults that are linked to the San Andreas and run in and around the Los Angeles metropolitan area that can, and have, triggered disaster.

In 1933, a 6.3 quake erupted at the southern section of the Newport-Inglewood Fault that runs from Beverly Hills to Newport Beach, killing 115 people in Long Beach and leveling large sections of the coastal city.

Prompted Field Act

More than 75% of the public schools in the area were either destroyed or damaged beyond repair, prompting the state Legislature to quickly pass the Field Act, which, ever since, has mandated that all new public schools meet minimum earthquake resistance standards.

“There’s no agreed-upon probability of when the Newport-Inglewood (Fault) could rupture again,” Caltech seismologist Clarence Allen said. “We just don’t know enough about this one, and it could be one of the most dangerous ones.”

Sykes said a 7.5 tremor on the northern Newport-Inglewood Fault could be more deadly than an 8.3 on the San Andreas because of the tremendous population that lives along this time bomb.

Lloyd Cluff, an earthquake geologist with Pacific Gas & Electric in San Francisco, said none of the minor faults that splinter off the San Andreas are capable of releasing the energy of an 8.3 quake.

Cluff said the lesser faults in the Los Angeles area--the Sierra Madre, the Elsinore, the White Wolf Fault near Bakersfield--probably would not muster any more destructive clout than a 6.0 to 6.2 on the Richter scale.

It takes a magnitude of 6.5 or more to topple a building in most cases, Cluff said.

The San Jacinto Fault, which runs under Riverside and San Bernardino, is a more worrisome. Cluff said this fault is capable of unleashing a 7.0 to 7.5 quake and, according to Allen, there is a 30 to 60% chance of it exploding in the next 20 years.

Southern California learned several years ago it was not immune to destruction.

At 6:01 a.m. on Feb. 9, 1971, the San Fernando Valley exploded in trembling waves of destruction.

Unreinforced brick and masonry buildings crumbled, freeway overpasses collapsed along with a veterans hospital, and 47 people died in the 6.6 quake that shook furiously for 12 long seconds.

Since that thunderous morning, the word quake is no longer associated with some evil phenomenon that only happens up north.

Proud of Preparedness

Now, Southern California officials boast that they are at the nation’s forefront in earthquake preparedness.

However, it should be noted that state and federal governments together spend $65 million a year on earthquake research and preparedness, while Japan, which lives with even greater earthquake perils, spends nearly $2.2 billion.

Los Angeles is the only city in Southern California that has written emergency plans, has a full-time earthquake staff in the Office of Emergency Services with a $500,000 budget (a $5-million budget has been proposed for next year), and an emergency operations center.

The city also has an ordinance requiring that nearly 8,000 unreinforced masonry buildings within the city limits either be strengthened by property owners or torn down.

Long Beach, Santa Ana, Riverside, San Bernardino and Santa Monica are the other Southern California cities to pass similar ordinances.

Progress Is Slow

Progress has been slow, however. According to Allen Asakura, chief of the earthquake safety division of the Los Angeles Building and Safety Department, only a few hundred of the 8,000 buildings have been retrofitted since the ordinance was passed four years ago and about 100 structures have been razed.

Building and safety manager Earl Schwartz said it will probably take another 15 years before all the buildings are brought up to minimum standards.

“No matter how much government does, no one can say we’re really prepared,” said Karen Patterson, an administrative officer in the Office of Emergency Management.

“If we have a quake, government is not going to be able to meet the needs of everyone,” she said. “People are going to have to be able to take care of themselves for at least three days. That we know.”