Tsunami hazard still lurks

“Hey Lori, is it true you now think Humboldt doesn’t have a tsunami threat?” The question took me aback because the person who asked me was my friend Mike Furniss. Mike is a scientist and well aware of our regional earthquake hazard. If he had heard such rumors, it was clear I needed to set the record straight.

YES, WE HAVE A TSUNAMI THREAT! Everyone hear that? My guess is that Mike was at the end of a “telephone” chain. It was a game we played at summer camp. The campers would stand in a circle and the “caller” would whisper a phrase to the kid next to them, and they would relate it to the next and so forth. By the time the story got fully round, it had always changed from how it had started.

I have no idea of the original conversation that started the chain that Mike heard. I may have been telling someone about the new North Coast tsunami maps that will be coming out in August or just explaining that not all parts of Cascadia are equal and Northern California’s tsunami threat is different than in Oregon or Washington. What is clear is that whatever I said was distorted in the retelling.

First the short version. If you feel an earthquake on or near the coast, the shaking is your warning that a tsunami may soon follow. Head inland or to higher ground as soon as you can safely move. Time is of the essence — grab your children, your grab-n-go kit and leave immediately. Use the posted tsunami zone signs as an indication of how far you need to head to be safe. Read no further — this is all you need to remember.

Now the medium answer: the North Coast may be affected by tsunamis generated by earthquakes nearby or from far away such as Alaska, Chile or Japan. For nearby earthquakes, follow the instructions above — feel the earthquake and head to high ground. You won’t feel the far away earthquakes and so the US Tsunami Warning System provides alerts. When an earthquake large enough to produce a tsunami occurs, alert bulletins are issued. If there is a need to evacuate, this information is disseminated via the Emergency Alert System on radio and television and through county emergency notification systems. Our most credible distant sources are at least four hours away from the North Coast and public