New Warning System at Ocean Beach
Plain-speech information to be broadcast in several languages

By Daniel Porras

On an unseasonably warm afternoon at Ocean Beach, surfers ride the waves while kite flyers, lovers and families enjoy the sun and breeze. To some city officials and regional scientists, Ocean Beach is not just San Francisco's popular sand and surf retreat, but a potential disaster zone - ground zero for the next big tsunami to hit the West Coast.

Ocean Beach is the focal point of a new tsunami preparedness plan sponsored by the SF Office of Emergency Services (OES). The plan was under development before recent tsunamis struck Southeast Asia, causing massive destruction. Emergency Services is hoping the new warning sirens will move people to higher ground at a moment's notice, a measure that could save thousands of lives.

According to Annemarie Conroy, the executive director at OES, the new system is "capable of sounding a warning siren and also acts as a multi-language public address system."

At ethnically diverse Ocean Beach, residents and beach-goers would hear a message in their native tongue telling them to rush to higher ground or instructing them where to catch a Muni bus for evacuation.

The new warning system, due to be fully operational in March, is a step-up from San Francisco's antiquated system, a network of 50 air raid sirens installed during World War II, of which only 18 are still functioning. The new plan replaces the old sirens - which emit a whine that alerts people to nothing in particular - with an advanced public address system consisting of 65 strategically-located sirens.

While the sirens can be used to warn citizens of all manners of impending doom, the OES is particularly interested in earthquakes and tsunamis. Afterall, geologists say faults off the West coast, like the Cascadia subduction zone, are ominously similar to the one that recently hit Asia.

"The (tsunami) we are prepared for is twice the size of the one that hit Southeast Asia," says Darcy Brown, OES' chief of administration.

After securing a $2.1 million federal Homeland Security Grant, OES prepared a plan to cope with a 50-foot-tall tsunami, an earthquake-generated wave that could easily rush three or four blocks into the neighborhoods around Ocean Beach. But, Brown adds, a tsunami that size "is a long shot."

Nonetheless, OES has an extensive tsunami plan that requires the cooperation of the SF Department of Telecommunications and Information Services, the SF Recreation and Park Department, SF Department of Public Works and the SF Unified School District. In addition to the new public address system and various evacuation plans, OES launched a new website, 72hours.org, named for the advice that all families should have at least 72 hours worth of emergency supplies on-hand in case of disaster, including batteries, flashlights, food and water. 

Tsunamis, from the Japanese "tsu," meaning harbor, and "nami," meaning wave, are often mistakenly referred to as tidal waves. The giant waves have nothing to do with incoming or outgoing tides. Tsunamis can be triggered by either seismic or non-seismic events and can originate locally or thousands of miles away, according to Elena Suleimani, a tsunami modeler at the Geophysical Institute at the University of Alaska. Non-seismic events include landslides, nuclear explosions and meteor impacts.

At Ocean Beach, a tsunami scenario could unfold like this: Geologists in Alaska would detect a large seismic event in the Pacific Ocean and would call the state of California's Office of Emergency Services, which would then notify San Francisco. San Francisco's OES would then activate the new public address system, which would give residents information and instructions on how to evacuate.

The chain of events could give residents as much as an hour - or as little as 10 minutes - to clear out of danger's way.

Daniel Porras wrote this article for the Neighborhood Environmental Newswire.