"It is believed . . . that the assumption of a magnitude 7.5 earthquake on the Newport-Inglewood fault represents a reasonable upper limit for earthquakes in the Los Angeles basin."
--A STUDY OF EARTHQUAKE LOSSES IN THE LOS ANGELES, CALIFORNIA AREA, BY THE NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
WHAT, REALLY, IS "the big one"? Most Southern Californians assume that it will come rolling out of the northeast, from the San Andreas Fault near Palmdale. After all, the San Andreas is the longest fault line in the state; it can--and someday will--throw off an earthquake classified as "great," meaning an event with a Richter-scale magnitude of 8.0 or more. There are few faults in the world capable of such violence, and this earthquake will be very destructive, one of the greatest natural disasters in the nation's history.
But most scientists do not believe that the San Andreas poses the greatest danger to Los Angeles. The San Andreas quake will strike from 40 miles away, and those miles will provide some degree of cushioning. Other faults--some small, capable of producing only modest tremors; others significantly more powerful--lie directly under the Los Angeles basin. The most dangerous of these is believed to be the Newport-Inglewood, which runs in a broken line from Culver City to Newport Beach. This fault is deadly because it is large, runs through the midst of the city, and is known to be active. The Long Beach earthquake of 1933, estimated at Richter 6.3, was a product of the Newport-Inglewood.
The following scenario is a fictional account of a magnitude 7.5 earthquake on the Newport-Inglewood as it might occur sometime in the near future. It is a worst-case view; a 7.5 magnitude earthquake is believed to be the largest that this fault can produce. But all of the scenes described are more than mere possibilities; similar events have occurred during other large earthquakes or have been hypothesized in government planning studies. The studies drawn on here were published by the U.S. Geological Survey, the California Division of Mines and Geology, and the National Oceanic and Atmospheric Administration. The scenarios were written in consultation with California seismologists. Though the scenes were rendered as realistically as possible, the characters are imaginary. Any similarity to real persons is purely coincidental.
4:30:01 p.m. ON THE SANTA MONICA FREEWAY
IT'S LIKE BEING stopped at the top of a Ferris wheel, John Anderson is thinking. He is settled in his Audi on his homeward drive, inching his way up the broad sweep of the transition ramp from the westbound Santa Monica Freeway to the San Diego, heading south. At the highest point on the ramp--when he can see west to the Pacific and south past miles of choked freeway--the traffic stops altogether, and Anderson perches over all the Westside, as if dangling in space. It's a clear, late-November afternoon, Los Angeles at its congested best. In front of him a young woman begins to bounce up and down in her Mustang, keeping rhythm to some unheard song. Then, quite gently at first, Anderson's car too begins to rock rhythmically, as though keeping time with the young woman.
Six miles down and just to the east of the freeway ramp, two huge blocks of the Earth's crust have been in a locked embrace for decades. Now they are breaking free. In a sudden release of the old tension, the westward block, known as the Pacific Plate, grinds and jerks its way north past the North American Plate. The total movement is tiny, only some 27.5 inches along the Newport-Inglewood Fault, but the energy released is greater than that of several nuclear bombs. The energy radiates upward and outward in waves moving 5 miles per second. The first waves are small, only capable of inducing that rocking motion on the Santa Monica Freeway. The next waves will be much larger, and to some Southern Californians they will seem to last forever. Within minutes, seismology stations all over the hemisphere will record the quake: a 7.5 on the Richter scale. Big, not huge. In an average year perhaps two earthquakes this large will occur somewhere on Earth. But most, obeying the law of averages, strike in sparsely settled regions. Not this one.
4:30:10 p.m. OVER LAX
THE BIG commercial DC-10 banks right over the ocean and heads for New York. It is pushing its way to 35,000 feet when it passes back over the city. Alice Wong looks down from her window seat, trying to spot her apartment in Ocean Park. Then she notices dust clouds rising from parts of Venice. She looks east and notices more puffs just past the San Diego Freeway in Westwood--almost as if large windstorms have struck randomly across the Westside. By now others on the plane are noticing the dust, and there's a buzz of comment in the coach cabin. Aisle passengers lean over to watch.