Most tsunamis that strike the Oregon coast are triggered by earthquakes in distant places, such as Alaska and Japan. These are called DISTANT TSUNAMIS. It takes these waves four to twelve hours to reach Clatsop County. The tsunamis are usually less than 5 ft high and pose little threat to local residents. Typically, only the lowest areas near rivers, estuaries, and beaches will be at risk.
Should a DISTANT TSUNAMI pose a hazard, NOAA emergency radios and municipal warnings will sound several hours before the wave will strike. Residents should tune in to local radio stations or television to learn of the hazard and evacuate to safe areas. Because there will be plenty of time to evacuate safely, it is permissible to evacuate by car. Remember- distant tsunamis pose only limited hazard under most situations, and there will always be enough time to evacuate safely.
LOCAL TSUNAMIS are triggered by long-duration, violent earthquakes less than 100 miles off shore along the Oregon Coast. They pose an extreme hazard to anyone living within tsunami inundation zones. Shaking may last for up to 5 minutes. Waves that follow the earthquake can be 40 ft high and will strike within about 20 minutes of the onset of shaking.
If you feel the ground shaking, take cover under a sturdy piece of furniture and hold on. If shaking lasts longer than 30 seconds, move to high ground as soon as you possibly can. Do not wait for an official warning. Take time only to grab previously packed survival supplies. Immediately evacuate by foot, bicycle, or small scooter. Do not drive, as roads will likely be impassable due to fallen power poles and damaged bridges.
Have plans prepared in advance to reconnect with loved ones. Budget your evacuation time carefully. Practice regularly to ensure you know your route to safety.
Be prepared. Be practiced. Be informed. Be safe.