As tragic as last week's earthquake was for the Angelenos involved, Southern Californians know that the worst may be yet to come. Geologists say there's a 50-50 chance that the `Big One' will strike the southern part of the state sometime in the next two decades, and the source of the jolt may not be the infamous San Andreas fault
by Shannon Brownlee, Traci Watson
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As every Southern Californian has heard time and again, the terrible quake known as the "Big One" will emanate from the San Andreas fault, the 650-mile-long rip in the Earth that runs the length of the state and whose southern tip skirts the eastern edge of the City of Angels. But now, geologists and disaster experts believe even greater devastation could be wreaked by a smaller quake in the Newport-Inglewood fault zone, a series of geologic fissures that traverse greater Los Angeles from Newport Beach to Beverly Hills.
Just how bad the devastation would be is the subject of a study by the California Division of Mines and Geology, which published a scenario in 1988 for a Newport-Inglewood quake of magnitude 7 on the Richter scale. The scenario's worst-case predictions are grim indeed. The quake would rock an area that is home to 9 million people, triggering landslides that would smash posh residential areas. Long stretches of freeway would buckle. The heaving earth would rupture water, power and natural-gas lines, igniting numerous gas and chemical fires. Damaged refineries and sewage facilities would dump oil and raw waste onto fabled beaches and into the sea.
While the Golden State cannot know when or where its next quake will strike, disaster planners have been using the 1988 scenario and four others like it to get ready. The state now boasts one of the most stringent building codes in the world and has in place well-coordinated disaster-relief plans for attending to the wounded and repairing damaged infrastructure, says Fred Turner, a structural engineer with the state's Seismic Safety Commission. The most difficult task remaining is shoring up existing structures to make them more earthquake resistant, a multibillion-dollar investment that the economically depressed state can ill afford right now. On the other hand, warns Turner, "We are competing against time."
Anticipating the worst In the worst-case scenario, these facilities would be hardest-hit:
Disabled hospitals All four of the acute care hospitals that lie within the fault zone would likely become non-functional, putting 1,900 beds out of service. Hospitals as far as 25 miles away would also be vulnerable, knocking out a total of 34 percent of the area's 14,500 beds.
Fractured highways More than 130 miles of highway and 350 bridges lie near enough to the Newport-Inglewood fault to be severely shaken. At least 16 arteries would likely be closed for at least 24 hours. Route 1 would be blocked or damaged by a landslide at Pacific Palisades and by liquefaction at Marina Del Ray. A six-mile stretch of the San Diego Freeway, which lies only 2 1/2 miles from the fault, would close indefinitely.
Damaged airports Four of the five principal public airports in LA and Orange Counties, which together serve 60 million passengers a year, could suffer damaged runways and buildings, though all but John Wayne Airport would probably stay open.
Dangerous harbors The Los Angeles-Long Beach Harbor would light up with a major fire from leaking oil facilities. Ships would suffer damage from smashing against their moorings in every harbor along the coast from Santa Monica to Newport Beach.
Free-flowing sewage The quake would rupture numerous water mains, and water treatment plants would be severely disabled. Residents would go without water for several days in some areas. Raw sewage would dump directly into streams, inundate neighborhoods, such as Huntington Beach, and foul the region's famous shoreline, in some cases for several weeks.
Flaming gas lines Gas line breaks would ignite fires along the fault zone and in adjacent areas.
Spilled oil Damage to refineries and storage facilities would spill petroleum into the sea at Alamitos Bay and Seal Beach, and would fuel fires inland.
The heaving earth Along the Newport-Inglewood fault zone, which straddles Los Angeles and Orange Counties, the ground would shake violently enough to move houses off their foundations, topple walls and masonry and sever underground pipes.
Landslides: Though the shaking would diminish in intensity farther away from the fault, landslides would pose a danger in narrow canyons -- incuding Topanga, a once tony address for Hollywood glitterati -- and on the densely populated hillsides.
Liquefaction: Large pockets of the city extending from San Fernando Valley to Newport Beach are in danger of liquefaction -- a geological term meaning that apparently solid soil turns to something like quicksand.
USN&WR -- Basic data: California Department of Conservation Division of Mines and Geology
