Tsunami Warning Sirens: Effective Or Obsolete?

Oct 16, 2015

Tsunami warning sirens wailed up and down the Washington coast Thursday. Students, businesses and medical workers drilled for an earthquake and tsunami as part of an annual event called "The Great Shakeout."

During the same drill, tsunami sirens stayed silent along the Oregon and Northern California coasts. There, some cities and counties are rethinking the cost-effectiveness of the warning systems.

So why do some people love their tsunami sirens and others can live without them?

When one of these sirens goes off you are unlikely to miss it if you are outside nearby, unlike say the buzz of a cell phone buried deep in your pocket. But inside a car with the radio on you can barely hear the siren. Similarly, imagine if you are at home watching Netflix. Would you hear the warning?

These days, emergency managers say sirens are for notifying people who are outdoors. But you can hear the close-by siren inside North Beach Junior & Senior High School in Ocean Shores, Washington. Principal Brett Mackey said the siren towers provide reassurance. He remarked it is "great" that federal grant money is paying for two more to be installed in his town and another one for Long Beach, Washington, too.

"I can hear from my house the audible saying when they do their Monday checks,” Mackey said. “I like that. I like the fact that we are fore-thinking in trying to warn people.”

‘Obsolete and difficult to get parts’

In Oregon, officials are rethinking the use of tsunami warning sirens. Tillamook County decommissioned several dozen sirens more than two years ago after the upkeep became unaffordable. The city of Waldport retired its three warning sirens a few months later.

Now in Coos Bay, fire chief Mark Anderson is reconsidering the effectiveness of the aging warning siren on the roof of a fire station close to the ocean.

"Tsunami warning sirens are difficult to maintain,” Anderson explained. “The one that we have is a 1950s or '60s-era civil defense siren, which is obsolete and difficult to get parts for."

Rather than upgrade, Anderson said his city and county are considering replacing warning sirens with a telephone based "reverse 911" alerting system.

Emergency managers further south on both sides of the Oregon-California border are singing the same tune about their sirens as smartphones become increasingly ubiquitous.

"The upkeep is really tough, you know with the salt air," Del Norte County (California) Emergency Services manager Cindy Henderson said. "I assume they'll be phased out over time. They're almost not needed anymore with everyone having (mobile) phones."

New technologies and mobile devices

Sirens though "are a fraught topic" among coastal residents according to Althea Rizzo. She's the geologic hazards coordinator for Oregon's Division of Emergency Management. Rizzo said different people prefer to get information in different ways.

"When you have populations of people that aren't keyed in to get other ways of getting the tsunami hazard information -- you know, tourists or people who are outside in park areas that may be away from cell phone access -- in those cases tsunami sirens are useful if they can convey information through voice,” Rizzo said.

Rizzo said without an intelligible voice message the siren is just noise. That’s why Rizzo is glad newer warning technologies tell you details and may even suggest what to do.

"If the tsunami is 10 to 16 hours away, you are going to be hearing about it, whether it is on radio, television, or Facebook. You can opt in through your cell phone,” Rizzo said. “There are going to be lots of different ways to get this information.”

Know your local warning system

One thing that's the same everywhere on the West Coast is that the sirens only provide warning in the case of a tsunami generated by a distant earthquake. If the Cascadia fault zone just offshore unleashes -- the feared "Big One" -- the violent shaking may be your only warning to run for higher ground.

Rizzo pointed out an important difference between Oregon and Washington. In Oregon -- and California too, for that matter -- siren upkeep and upgrades are a local responsibility. Washington state by contrast has a standardized, satellite-activated tsunami siren network for which the state pays all the maintenance.

Wherever you live, Rizzo said it's up to you to learn what warning systems your community offers and how to opt in if necessary.

Many counties are automatically enrolling all local landlines in their reverse 911 mass notification systems, sometimes known by a vendor’s brand name such as Everbridge. Citizens can also register to receive a text or email notification if preferred. Typically, mobile phone users must opt in.

These reverse 911 systems are separate from the recently deployed wireless emergency alert capability, which can push a noisy alarm and short message to late-model smartphones within range of specific cellular towers in a danger zone.

A NOAA weather radio is another notification option. Some counties have also practiced using Civil Air Patrol overflights with a loudspeaker to reach recreationists in outlying areas.