Learning from the big quake, getting ready for the future - includes free Sunset reprint for earthquake help available now

Learning from the big quake, getting ready for the future On October 17, northern California again learned first-hand how devastating an earthquake can be. Even though many of us are still experiencing the tragedy of the 7.1 quake theat rocked the San Francisco and Monterey Bay areas, that grim event does offer us a fresh opportunity to study how a major temblor affects our houses and communities.

One thing we learned immediately was the capacity of groups and individuals to help when needed. Crews worked around the clock to clear roads and restore power, while disater aid groups provided medical help, food, clothing, and shelter to earthquake victims. Volunteers were invaluable--directing traffic, pitching in at shelters, helping the stranded and injured.

Private and corporate donations of money and goods poured into relief agencies.

Soon after the quake, Sunset editors were inspecting damaged houses, meeting with geologists, engineers, and public officials. We wanted to find out what happened in order to help our reader be better prepared next time.

Which houses held up,

which didn't? How could we

have been better prepared?

It's heartening to see that modern building codes are working: most houses built after the 1930s survived with relatively minor or no damage.

There were exceptions. Some houses that were poorly built or on steep or unstable ground suffered regardless of their age. Chimneys and other unreinforced masonry proved particularly vulnerable, collapsing at new and old homes alike.

Older homes throughout the quake zone demonstrated clear patterns of failure. We can learn from these failures--as well as from some successful methods of coping and recovering.

Porches fell off. When supports shook loose, older porches inadequately tied to houses yanked free, their roofs crashing down. Beefing up structural ties might have save these tacked-on appendages.

Cripple walls moved. Many older houses rest on cripple walls (short 2-by-4 walls between foundation and first floor). As the ground moved, cripple walls buckled or tipped, and houses simply dropped to their knees. This might have been avoided if the cripple walls had been sheathed with plywood and if framing was free of termites and dry rot. Also., sill plates should have been bolted to foundations.

Chimneys gave way. Bricks rained down as chimneys crumbled--sometimes falling away from the house, sometimes crashing through the roof. Some chimneys could have been strengthened with steel and concrete, then braced to stabilize them and control where they might fall. Any chimney that got a good shaking should be checked for hidden damage that could present fire danger.

Water heaters tipped over. Many fell, some breaking gas lines and starting fires. Metal strapping secured to studs could have kept heaters in place.

Shelves emptied, furniture toppled. If they weren't anchored to wall studs, large items--bookshelves, heavy furniture, armoires--skidded or tumbled. Breakage of smaller items could have been minimized by using eye screws to hang mirrors and art objects from wall studs and by stowing breakables in securely lathced cabinets.

Emergency planning paid off. Most people within the quake zone suffered at least temporary loss of power, and hardest hit areas were also without gas and water. Telephone lines were jammed for days.

In one isolated spot--Scotts Valley, near the quake's epicenter in the Santa Cruz Mountains--preplanning by a group of residents saved houses and maybe lives. They had learned each other's house layouts. They had set up secure caches of water and purification supplies, food, medications, flashlights and radios (with fresh batteries), blankets, and other emergency supplies. They knew where to find shut-off valves and wrenches. And they had exchanged keys and home, work, and school telephone numbers.

The quake made clear the need to have emergency plans not just at home, but at work and in children's schools. At each place, there should be emergency supplies to last at least three days.

Mass transit showed its value. The quake and its aftermath demonstrated the importance of alternatives to the automobile. With a major bridge and several freeways closed, BART (Bay Area Rapid Transit), Caltrain, and an increased fleet of ferries kept people moving. Car pools, expanded bus service, and flexible work hours also helped reduce traffic.

What did the quake do to you? Help

us with a survey

As we set about updating our 1982 article on earthquake preparedness (see below), we'd like to know how Sunset readers fared during and after the quake. What steps had you taken to prepare your family, house, and property? What worked well? And what didn't? We'd be particularly interested to know if you followed any of the advice in our 1982 article.

To share ideas, or to receive a questionnaire that will help us learn from your experience, write to Earthquake Survey, Sunset Magazine, 80 Willow Rd., Menlo Park, Calif. 94025.