Tsunami Resources
Florence Area Tsunami Information
IF YOU LIVE AT OR VISIT THE COAST, THE INFORMATION ON THIS PAGE MAY SAVE YOUR LIFE. PLEASE TAKE THE TIME TO READ IT AND SHARE WHAT YOU HAVE LEARNED WITH YOUR FAMILY AND FRIENDS.
The evacuation zones on the map were developed by the Oregon Department of Geology and Mineral Industries in consultation with local officials. It is intended to represent a worst-case scenario for a tsunami caused by an undersea earthquake near the Oregon coast.
Evacuation routes were developed by local officials and reviewed by the Oregon Department of Emergency Management.
The map is intended for emergency response and should not be used for site-specific planning.
A tsunami is a series of sea waves usually caused by a displacement of the ocean floor by an undersea earthquake. As tsunamis enter shallow water near land, they increase in height and can cause great loss of life and property damage.
Recent research suggests that tsunamis have struck the Oregon coast on a regular basis. They can occur at any time, day or night. Typical wave heights from tsunamis occurring in the Pacific over the last 80 years have been 20–45 feet at the shoreline. A few waves however have been much higher—as much as 100 feet or more—because of local conditions.
We distinguish between a tsunami caused by an undersea earthquake near the Oregon coast (LOCAL TSUNAMI) and an undersea earthquake far away from the coast (DISTANT TSUNAMI).
A LOCAL TSUNAMI could come onshore within 15 to 20 minutes after the earthquake—before there is time for an official warning from a national warning system. Ground-shaking from the earthquake may be the only warning you have. Evacuate quickly!
A DISTANT TSUNAMI will take four hours or more to come onshore. You will feel no earthquake, and the tsunami will generally be smaller than that from a local earthquake. There will typically be time for an official warning and evacuation to safety.
Some communities will signal the need for evacuation for a distant tsunami by sounding a STEADY 3-MINUTE SIREN BLAST. Read the Tsunami Sirens Protocol page for more information.
All coastal communities will receive announcements over NOAA weather radio that the local area has been put into an official TSUNAMI WARNING.
In isolated areas along beaches and bays, you may not hear a warning. Here, a sudden change of sea level should prompt you to move immediately inland to high ground.
If you hear the 3-minute blast or see sudden sea-level changes, evacuate away from shoreline areas, then turn on your local broadcast media or NOAA weather radio for further information.
FOR BOTH DISTANT AND LOCAL TSUNAMIS:
-
Evacuate on foot if at all possible because of potential traffic jams.
-
Stay away from potentially hazardous areas until you receive ALL CLEAR from local officials. Dangerous waves can persist for several hours, and local officials must inspect all flooded or earthquake-damaged structures before anyone can go back into them.
-
If you need help evacuating, tie something WHITE (sheet or towel) to the front doorknob. Make it large enough to be visible from the street. If the emergency is a distant tsunami, then help may arrive. In the event of a local earthquake and tsunami, it is unlikely that anyone will help you, so make a plan and be prepared!
-
After the evacuation, check with the local area commander if you can help with special skills or need assistance with locating lost family.
