tsunamis are potentially dangerous, even though they may not damage
every coastline they strike. Damaging tsunamis are very rare. Our
coastlines are vulnerable, but tsunamis are infrequent. Understand
the hazard and learn how to protect yourself, but don't let the
threat of tsunamis ruin your enjoyment of the beach.
West Coast/Alaska Tsunami Warning Center (WC/ATWC) is responsible
for tsunami warnings for California, Oregon, Washington, British
Columbia, and Alaska.
Pacific Tsunami Warning Center (PTWC) is responsible for
providing warnings to international authorities, Hawaii, and U.
S. territories within the Pacific basin. The two Tsunami Warning
Centers coordinate the information being disseminated.
The WC/ATWC and PTWC may issue the following bulletins:
A tsunami was or may have been generated, which could cause damage;
therefore, people in the warned area are strongly advised to evacuate.
WATCH: A tsunami was or may have been generated, but is at least
two hours travel time to the area in watch status. Local officials
should prepare for possible evacuation if their area is upgraded
to a warning.
ADVISORY: An earthquake has occurred in the Pacific basin, which
might generate a tsunami. WC/ATWC and PTWC will issue hourly bulletins
advising of the situation.
INFORMATION: A message with information about an earthquake
that is not expected to generate a tsunami. Usually only one bulletin
Be familiar with the tsunami warning signs. A strong earthquake
lasting 20 seconds or more near the coast may generate a tsunami.
A noticeable rapid rise or fall in coastal waters is also a sign
that a tsunami is approaching.
most frequently come onshore as a rapidly rising turbulent surge
of water choked with debris. They are not V-shaped or rolling
waves, and are not "surfable."
may be locally generated or from a distant source. In 1992,
the Cape Mendocino, California, earthquake produced a tsunami that
reached Eureka in about 20 minutes, and Crescent City in 50 minutes.
Although this tsunami had a wave height of about one foot and was
not destructive, it illustrates how quickly a wave can arrive at
nearby coastal communities and how long the danger can last.
1957, a distant-source tsunami generated by an earthquake in the
Aleutian Islands in Alaska struck Hawaii, 2,100 miles away. Hawaii
experienced $5 million in damages from that tsunami.
for a Tsunami
a Family Disaster Plan. Please see the "Family
Disaster Plan" section for general family planning information.
Tsunami-specific planning should include the following:
about tsunami risk in your community. Contact your local emergency
management office or American Red Cross chapter. Find out if your
home, school, workplace or other frequently visited locations are
in tsunami hazard areas. Know the height of your street above sea
level and the distance of your street from the coast or other high-risk
waters. Evacuation orders may be based on these numbers.
you are visiting an area at risk from tsunamis, check with the
hotel, motel, or campground operators for tsunami evacuation information
and how you would be warned. It is important to know designated
escape routes before a warning is issued.
If you are at risk from tsunamis, do the following:
an evacuation route from your home, school, workplace, or any
other place you'll be where tsunamis present a risk. If possible,
pick an area 100 feet above sea level or go up to two miles inland,
away from the coastline. If you can't get this high or far, go as
high as you can. Every foot inland or upwards may make a difference.
You should be able to reach your safe location on foot within 15
minutes. After a disaster, roads may become impassable or blocked.
Be prepared to evacuate by foot if necessary. Footpaths normally
lead uphill and inland, while many roads parallel coastlines. Follow
posted tsunami evacuation routes; these will lead to safety. Local
emergency management officials can help advise you as to the best
route to safety and likely shelter locations.
your evacuation route. Familiarity may save your life. Be able
to follow your escape route at night and during inclement weather.
Practicing your plan makes the appropriate response more of a reaction,
requiring less thinking during an actual emergency situation.
a NOAA Weather Radio with a tone-alert feature to keep you informed
of local watches and warnings. The tone alert feature will warn
you of potential danger even if you are not currently listening
to local radio or television stations.
to your insurance agent. Homeowners' policies do not cover flooding
from a tsunami. Ask about the National Flood Insurance Program.
tsunami with your family. Everyone should know what to do in
case all family members are not together. Discussing tsunamis ahead
of time will help reduce fear and anxiety, and let everyone know
how to respond. Review flood safety and preparedness measures with
Assemble a Disaster Supplies Kit Please see the section "Disaster
Supplies Kit" for general supplies kit information. Tsunami-specific
supplies should include the following:
Supplies Kit in an easy-to-carry contanier (backpack) near your
- Disaster Suplies Kit basics.
How to Protect Your Property
building or living in buildings within several hundred feet of the
coastline. These areas are more likely to experience damage from
tsunamis, strong winds, or coastal storms.
Make a list of items to bring inside in the event of a tsunami.
A list will help you remember anything that can be swept away by
coastal homes. Most tsunami waves are less than 10 feet. Elevating
your house will help reduce damage to your property from most tsunamis.
flood preparedness precautions. Tsunamis are large amounts of water
that crash onto the coastline, creating floods.
an engineer check your home and advise about ways to make it more
resistant to tsunami water. There may be ways to divert waves away
from your property. Improperly built walls could make your situation
worse. Consult with a professional for advice.
information obtained from