THE BIG ONE : Worse Than San Andreas

Mention earthquakes and Orange County residents look to the notorious San Andreas Fault, 30 miles northeast of the Los Angeles metropolitan area. Yet experts say a greater danger lies underfoot the Newport-Inglewood Fault slicing north along the Orange County coast from Newport Beach. It has already provided the worst urban quake in Southern California history--the 1933 Long Beach Earthquake that killed 120 people and caused $40 million damage. Yet that 6.3-magnitude jolt was not the worst this fault can deliver. Geologists believe a quake of at least magnitude 7 is possible--and that would cause more death and destruction than an even greater quake along the San Andreas. Based on interviews with experts and a scenario recently published by the state, here is what Orange County would be like if a 7.3-magnitude quake struck at 7:41 on a typical Monday morning.

* A major water line snaps near Fullerton Creek in Buena Park

* El Toro Marine Corps Air Station closes for 6 hours, but an inspection of runways finds no serious damage because the facility is inland and not subject to significant ground settlement

* John Wayne Airport sustains damage to the runway, fuel tanks and other structures. Closed for 24 hours, it reopens after repairs are made at the northeast end of its runway. But surrounding freeway damage makes it difficult to passengers to reach the terminal

* Sewage plant in Fountain Valley, one of two serving 80% of the county’s 2.1-million residents is severely damaged and likely to remain that way for weeks or months. Raw sewage overflows into streets and the ocean

* The Los Alamitos Armed Forces Reserve Center--an emergency earthquake operations post--sustains significant damage to runways, fuel tanks and structures. Closed for 24 hours, it reopens for landings of C-130 cargo planes bearing relief supplies

* Alamitos power plant is shut down for more than 3 days

* Haynes power plant is shut down for more than 3 days

* A major natural gas line to the Huntington Beach power plant ruptures east of Bolsa Chica Beach State Park

* Huntington Beach power plant is shut down for more than 3 days

* Sewage plant in Huntington Beach, one of two serving 80% of the county’s 2.1-million residents is severely damaged and likely to remain that way for weeks or months. Raw sewage overflows into streets and the ocean

* San Onofre nuclear power plant, 5 miles south of San Clemente, is undamaged

* Storage tanks in Seal Beach are damaged and spill fuel into Alamitos Bay

* Water Supply

Water lines and pumping stations near the fault are damaged, forcing coastal cities to rely on local storage facilities and tank trucks for drinking water

* Natural Gas

Thousands of underground natural gas connections are leaking and many have been ignited

Phones

Throughout the region, telephone switching equipment is overloaded and automatically shuts down a few minutes after the quake. Within 25 miles of the fault, phone lines designated for essential services are 25% usable after the first day, 50% usable after the second day and 75% usable at the end of the third day. The restoration of phone service to the public will be significantly slower

‘Strike-slip’ Fault

* Earthquakes along the Newport-Inglewood and San Andreas fault occur when earth on either side of the fault line lurches horizontally in opposite directions. In contrast to the “strike-slip” fault, a “thrust” fault--such as the one that caused the 1971 Sylmar-San Fernando quake--has one sides that moves vertically up or down against the other

Richter Scale

In 1935, former Caltech professor Charles F. Richter devised a logarithmic scale that grades the severity of earthquakes. Each whole number on the scale indicates a quake that is 10-times greater than the number before. A magnitude of 5.0, for example, would be 10-times a 4.0, but 100-times a 3.0. The atomic bomb dropped on Hiroshima--about 20,000 tons of TNT--would amount to a 6.3 earthquake. So the 7.3-magnitude quake in the Newport-Inglewood scenario would exert 10-times the force 8.3 San Francisco 1908 8.1 Mexico City 1985 7.7 Kern County 1952 7.3 Scenario Quake 7.0 Eureka 1980 6.7 Coalinga 1983 6.6 Imperial Valley 1979 6.4 San Fernando 1971 6.3 Santa Barbara 1925 6.3 Long Beach 1933 5.9 Whittier Narrows 1987

Hospitals

Hospitals nearest the fault zone lose the use of 50% of their beds due to loss of power and equipment failures. Hospitals further away suffer 25% loss.

1. La Palma Intercommunity Hospital 136 beds 7901 Walker St. La Palma

2. Los Alamitos Medical Center 173 beds 3751 Katella Ave. Los Alamitos

3. Humana Hospital-Westminster 182 beds 200 Hospital Circle Westminster

4. Fountain Valley Regional Hospital and Medical Center 287 beds 17100 Euclid St. Fountain Valley

5. Humana Hospital-Huntington Beach 141 beds 17772 Beach Blvd. Huntington Beach

6. Pacifica Community Hospital 109 beds 18792 Delaware St. Huntington Beach

7. Coastal Communities Hospital 215 beds 2701 S. Bristol St. Santa Ana

8. College Hospital Costa Mesa 99 beds 301 Victoria St. Costa Mesa

9. Hoag Hospital 471 beds 301 Newport Blvd. Newport Beach

10. Saddleback Hospital and Health Center 155 beds 24451 Health Center Dr. Laguna Hills

11. South Coast Medical Center 268 beds 31872 Coast Highway South Laguna

12. San Clemente Hospital 116 beds 654 Camino de los Mares San Clemente

Highways

* San Diego Freeway, closed through Long Beach due to bridge and pavement damage, has one lane open where it meets the San Gabriel Freeway and is partly open through Seal Beach. Considerable damage has closed all 10 lanes through Westminster, Huntington Beach, Fountain Valley, Costa Mesa and Irvine to just beyond Jamboree Road. Some parts are expected to remain so for 3 days, but the stretch in Costa Mesa and Irvine will be closed indefinately

* MacArthur Boulevard is closed on both sides of San Diego Creek, near the UC Irvine campus, and is expected to remain so for 3 days

* Pacific Coast Highway is closed from Seal Beach to Corona del Mar and is expected to remain so for 3 days

* Costa Mesa Freeway is severely damaged at the Pacific Coast Highway interchange and no traffic is expected to use it for 3 days. The freeway is partly open from there to the San Diego Freeway, but the remaining stretch to the Santa Ana Freeway is closed due to heavy bridge and interchange damage and is expected to remain so for 3 days

* Garden Grove Freeway is damaged at interchanges with the San Diego Freeway, where traffic will be blocked for 36 hours, and Beach Boulevard, where traffic will be blocked for more than 3 days. In Garden Grove, there is light damage at the freeway’s interchange with Harbor Boulevard. But major ground failures along the freeway are expected to block traffic for at least 2 days

* Santa Ana Freeway is open but has localized damage from Buena Park to San Juan Capistrano

* Artesia/Riverside Freeway is open but has localized damaged from Buean Park to Yorba Linda

* Orange Freeway is open but has localized damage from Brea to the Santa Ana Freeway

* Beach Boulevard is open but has localized damage from Buena Park to Garden Grove. It is partly closed from the Garden Grove Freeway to the San Diego Freeway and around Pacific Coast Highway

A Closer Look

Geologists say the width of the Newport-Inglewood Fault line varies and much of it lies beneath the surface

Source: Planning Scenario For A Major Earthquake On The Newport-Inglewood Fault Zone, California Department of Conservation, Division of Mines and Geology, 1988