A tsunami is a series of waves generated by the displacement of water, usually caused by earthquakes, volcanic eruptions, landslides or other disturbances. The International Tsunami Warning System monitors for tsunamis in the Pacific Ocean and issues warnings to local authorities. The best sources of information during a tsunami are the two Tsunami Warning Centers and local emergency management agencies who provide warning messages to notify the public of any tsunami risks.

1. • A tsunami also known as a seismic sea wave, is a series of waves in
a water body caused by the displacement of a large volume of
water, generally in an ocean or a large lake.
• Earthquakes, volcanic eruptions and other underwater explosions
(including detonations, landslides, glacier calvings, meteorite
impacts and other disturbances above or below water all have the
potential to generate a tsunami.
• Unlike normal ocean waves, which are generated by wind, or tides,
which are generated by the gravitational pull of the Moon and the
Sun, a tsunami is generated by the displacement of water.

2. What is the best source of information in a tsunami situation?
The International Tsunami Warning System monitors ocean waves after any
Pacific earthquake with a magnitude greater than 6.5. If waves are detected,
warnings are issued to local authorities who can order the evacuation of low-
lying areas if necessary. The National Oceanic and Atmospheric
Administration (NOAA)’s National Weather Service operates two tsunami
warning centers:
1. West Coast/Alaska Tsunami Warning Center (WC/ATWC),
Palmer, Alaska. Serves Alaska, Washington, Oregon, California, the U.S.
Atlantic and Gulf of Mexico coasts, Puerto Rico, the U.S. Virgin Islands and
Canada.
2. Pacific Tsunami Warning Center (PTWC), Ewa Beach, Hawaii.
Serves Hawaii and the U.S. Pacific territories, and as an international
warning center for the Pacific and Indian oceans and the Caribbean Sea.

3. Tsunami Fact vs Fiction
1. Fiction
Tsunamis are giant walls of water.
Fact
Occasionally, tsunamis can form walls of water (known as tsunami bores) but
tsunamis normally have the appearance of a fast-rising and fast-receding flood.
They can be similar to a tide cycle occurring in just 10 to 60 minutes instead of
12 hours.
2. Fiction
A tsunami is a single wave.

4. Fact
A tsunami is a series of waves. Often the initial wave is not the largest. In fact,
the largest wave may not occur for several hours. There may also be more than
one series of tsunami waves if a very large earthquake triggers local landslides
which in turn trigger additional tsunamis.
3. Fiction
Boats should move to the protection of a bay or harbor during a tsunami.
Fact
Tsunamis are often most destructive in bays and harbors, not just because of
the waves but because of the violent currents they generate in local waterways.
Tsunamis are least destructive in deep, open ocean waters.

5. 4. Fiction
A tsunami is the same thing as a tidal wave.
Facts
Tidal waves are regular ocean waves, and are caused by the tides. These
waves are caused by the interaction of the pull of the moon’s gravity on
the earth. A “tidal wave” is a term used in common folklore to mean the
same thing as a tsunami, but is not the same thing.
Be aware of the signs of a tsunami:
•A strong earthquake lasting 20 seconds or more near the
coast.
•A noticeable rapid rise or fall in coastal waters.

6. Developing and Delivering Effective Warning Messages
• The likelihood of individuals responding to tsunami warnings depends on
the quality, clarity, and accuracy of the official warning messages they
receive from the two Tsunami Warning Centers (TWCs) and/or local and
state emergency management agencies.
• An effective message contains the necessary information to motivate
individuals to take self-protective action and must reach at-risk people in
a timely fashion.
• It is critical that warning messages: are accurate and consistent; use
language that allows a person to visualize the proper response; make
clear when recommended actions should begin and finish.
• identify who needs to evacuate and who does not.
• explain how taking the protective action will reduce the pending
consequences of not taking action at all.

7. Preparing in Advance Through a Consistent Public Education Campaign
Surviving a tsunami depends on the:
• ability of an individual in the hazard zone to recognize warning signals
• make correct decisions
• act quickly.
For near-field tsunamis
waves will arrive within minutes after generation; therefore, at-risk
individuals will need to recognize natural cues such as the ground
shaking or the receding of the water line as the primary warning.
Knowledge and readiness gained through pre-event education may save
lives.

8. For far-field tsunamis
waves will arrive several hours after generation, and individuals need
to understand official warnings and follow instructions given by local
agencies.
Tips
•To escape a tsunami, go as high and as far as you can –
feet above sea level or 2 miles away.
•Every foot inland or upward may make a difference!
•if you can see the wave, you are too close for safety.

9. Detecting and Forecasting Tsunamis
The two separate Tsunami Warning Centers monitor seismic activity to
assess the potential for tsunami threats from earthquakes.
• The content of the tsunami information statement, advisory, watch,
or warning from the TWC is decided solely on seismic parameters and
the historical record, if any, of past tsunamis generated in the area of
the earthquake.
• Based on their own data analysis, the TWCs independently decide
whether to issue alerts to the emergency managers in their respective
areas of responsibility.

10. How to Prepare for a Tsunami
Protecting your family
• Talk about tsunamis with your family so that everyone knows what
to do in a tsunami situation. Discussing ahead of time helps reduce
fear, particularly for younger children.
• Check at your workplace and your children's schools and day care
centers to learn if they are in a tsunami hazard area or inundation
zone. Learn about their evacuation plans, especially the designated
spot where you will pick up your children.
• Plan evacuation routes from your home, school, workplace and
other places you could be

11. where tsunamis present a risk.
• If possible try to pick areas 100 feet above sea level or 2 miles
inland.
• If you cannot get that high or far, go as high or far as you can.
Every foot inland or upward may make a difference. You
should be able to reach the highest ground possible on foot
within 15 minutes.
• Practice your evacuation routes. Familiarity may save your life.
Be able to follow your escape route at night and during
inclement weather.

12. Protecting your home
• Avoid 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.
• If you do live in a coastal area, elevate your home to help reduce
damage. Most tsunami waves are less than 10 feet (3 meters).
• Take precautions to prevent flooding.
• Have 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.

13. Know the difference!
•A Tsunami WARNING means a tsunami may
generated and could be close to your area.
•A Tsunami WATCH means a tsunami has not
verified but could exist and may be as little
• Make a list of items to bring inside in the event of a tsunami
watch or warning being issued for your area. But remember, you
may need to evacuate immediately – don’t risk your safety to
save your belongings

14. Be sure you're Red Cross Ready.
That means:
• Assembling an emergency preparedness kit.
• Creating a household evacuation plan that includes your pets.
• Staying informed about your community’s risk and response
plans.
• Educating your family on how to use the Safe and Well
website.
• Download the Emergency App for iPhone >> or for Android >>

15. During a Tsunami
If You Feel a Strong Coastal Earthquake
• Drop, cover, and hold on to protect yourself from the earthquake.
• When the shaking stops, gather members of your household and review your
evacuation plan. A tsunami may be coming within minutes.
• Use a Weather Radio or stay tuned to a Coast Guard emergency frequency station
or a local radio or television station for updated emergency information.
• Follow instructions issued by local authorities. Recommended evacuation routes
may be different from the one you planned, or you may be advised to climb higher.

16. • Take your emergency preparedness kit. Having supplies will make you more
comfortable during the evacuation.
• Get to higher ground as far inland as possible. Watching a tsunami from the
beach or cliffs could put you in grave danger. If you can see the wave, you are too
close to escape it.
• Avoid downed power lines and stay away from buildings and bridges from
which heavy objects might fall during an aftershock.
• Do not assume that after one wave the danger is over. The next wave may be
larger than the first one.

17. •Get to higher ground as far inland as possible. Watching a tsunami
from the beach or cliffs could put you in grave danger. If you can see
the wave, you are too close to escape it.
• Avoid downed power lines and stay away from buildings and
bridges from which heavy objects might fall during an aftershock.
• Stay away until local officials tell you it is safe. A tsunami is a series
of waves that may continue for hours. Do not assume that after one
wave the danger is over. The next wave may be larger than the first
one.

18. After a Tsunami
If you do nothing else:
• Let friends and family know you’re safe.
• Register yourself as safe on the Safe and Well website.
• If evacuated, return only when authorities say it is safe to do so.
• Continue listening to local news or a NOAA Weather Radio for
updated information and instructions.
• If people around you are injured, practice CHECK, CALL, CARE. Check
the scene to be sure it’s safe for you to approach, call for help, and if
you are trained, provide first aid to those in need until emergency
responders can arrive.

19. Specific Site Planning Strategies to Reduce Tsunami Risk
• Avoid Inundation Areas: Site Buildings or infrastructure away from hazard area or locate
on a high point.
• Slow Water: Forests, ditches, slopes, or berms can slow down waves and filter out debris.
The success of this method depends on correctly estimating the force of the tsunami.
• Steering: Water can be steered to strategically placed angled walls, ditches and paved
roads. Theoretically, porous dikes can reduce the impact of violent waves.
• Blocking : Walls, hardened terraces, berms and parking structures can be built to block
waves.he house and household in a wide community context such as whether it is a
majority or minority situation, the conflict situation and ownership issues.

20. REFERENCES:
1. THE AMERICAN RED CROSS
2. Designing for Tsunamis Seven Principles for Planning and Designing
for Tsunami
Hazards. NOAA, USGS, FEMA, NSF, Alaska, California, Hawaii, Oregon,
and Washington. (2001). National Tsunami Hazard Mitigation
Program (NTHMP)
3.Tsunami Awareness Kit General Tsunami Resources.(2005). Tsunami
Mitigation Strategies. Prepared by the Pacific Disaster Center.