Ten Common Misunderstandings about Tsunamis

By Patrick Corcoran, Hazards Outreach Specialist
Oregon Sea Grant program, Oregon State University

Do sirens mean run!

No. Sirens mean turn on your TV or radio. Sirens indicate a distant tsunami. You will have plenty of time to evacuate the inundation zone if that is necessary. Most people will not need to go anywhere. (Recall Samoa, Chile and Japan.) If your home is on the beach or along a waterway you may decide to move to high ground, but there is no need to move more than a few blocks. If you do evacuate, gather your medications and personal items and leave the zone for 12 hours. If you are in an inundation zone when the siren sounds, but you live outside of the zone, go home, or visit someone out of the zone. Make friends in high places!

Consider buying a NOAA All Hazards radio. The radios serve as “personal sirens” for distant events, and immediately provide information on where the earthquake occurred and how long it will take to get here. The radios are widely available at electronics stores.

We live on a hill. Are we safe?

That’s true only if you’re at home when it happens. You might live on a hill, but you’re in danger if you happen to be working, shopping, recreating or driving through an inundation zone when the Big One hits. Also, people on hills need to worry about damage during the earthquake and subsequent landslides.

Will we be able to drive to safety?

Probably not after the Big One because of earthquake damage. If it’s obvious that you can do it, do it. But don’t plan on it. Your car may be under the rubble that used to be your garage. Even if your car is OK, the garage door probably won’t open. Even if it does, the roads will be impassable due to fallen trees and power poles, damaged bridges and from the scores of landslides that will occur on all major roadways. Don’t rely on a car strategy; instead, plan to run to safety. If you live in an inundation zone, practice your evacuation route so you can do it in the dark.

Will we be able to connect by phone?

Don't count on it. After the local Big One, telephone poles and cell towers will topple, and any working lines will be jammed. Satellite phones may work. Critical service providers and other key individuals and agency might consider getting satellite phones. OnStar systems in cars are satellite phones. Ham radios will work and local operators are prepared. (In a distant event, the phone lines will be intact but may be overwhelmed. Sometimes text messaging works when phone service doesn’t.)

Will my emergency kit be helpful?

After the local Big One, the odds of you having your kit handy are low. Emergency kits can be helpful, but it’s probably more important to take an advanced first aid class.  Remember, many homes out of the inundation zone will be OK. You can get supplies from neighbors’ pantries and medicine cabinets. Note: prescription medications can be a matter of life and death. Consider identifying people in safe areas who take the same medications as you. Evacuate to their house if you’re caught without medicines during the Big One. (In a distant event, grab a go-bag of medications if you need to evacuate the inundation zone.)

Will we have to camp out for a week after the Big One?

Some will, but most probably will not. Residents in outlying areas may be cut-off for several days or weeks due to landslides. But in town, it’s more likely that some neighborhoods will be devastated while others will be relatively intact. The more likely scenario is “neighbor helping neighbor.”

Will someone come and save us?

After the local Big One, emergency management professionals (police, fire, ambulance) will be in the same boat as everyone else — unable to drive their vehicles over destroyed bridges, landslides and debris. As good as our local emergency officials are, they will have only a limited ability to help. Do not expect personal attention.

Are tsunamis waves?

A tsunami is not a “wave,” which moves up-and-down, but the ocean moving sideways. Here’s an analogy. When your dog laps water in his bowl, he’s making “waves.” When he kicks the bowl across the floor and it slams into the refrigerator and the water spills over the side, that’s a tsunami. The approaching tsunami looks more like a storm surge. Even small tsunamis carry tremendous power and come in a series of surges lasting up to 12 hours.

Is there anything I can do?

Individuals and families can improve their odds of surviving earthquakes and tsunamis. Take an hour to learn what you need to know, and then let it go. Enjoy life on the coast. This is a beautiful place to live, work and play.