Tsunami Warning Center
4 Levels of Messaging

+ Danger!
| + Run for High Ground!

; r | + Follow Emergency

Instructions.

+ Possible Strong and
Dangerous local
Currents.

+ Stay tuned for local
Emergency guidance.

+ Potential Danger. z

+ Stayed tuned for N
more information.

U. S. Tsunami

‘Product Definitions:

A potential tsunami with
significant widespread inundation is
imminent or expected. Widespread,
dangerous coastal flooding accompa-
nied by powerful currents is possible
and may continue for several hours
after the arrival of the initial wave.

Advisory:-A potential tsunami
which may produce strong currents or
waves exists. Significant widespread
inundation is not expected.

Watch: A potentially dangerous
distant seismic event has occurred
which may later impact the watch
area with a tsunami. Be ready to take
action if a warning is issued.

InformatiomStatements: An
earthquake has occurred or a
tsunami warning, watchpor advisory
has been issued for another seciion
of the ocean. In most cases,
information statements are issued to
indicate there is no threat of a
destructive tsunami in your area.

flooding elevation of the area
where you live, work, or visit.

V Learn a location of the nearest

tsunami shelter and/or safe area.

V Learn the safe route to shelter.
o Have a family emergency plan.
VW Havea portable disaster supply
kit with three days supply of food
and water. Keep the kit ina
location you can access quickly.
V In addition, consider maintaining

a two-week supply of food and
water in your home.

For more information about tsunamis:

www.tsunami.gov

SG,

NATIONAL WEATHER SERVICE


What is a Tsunami?

Tsunamis are ocean waves
generated by a sudden change of
the ocean water level, most often
caused by earthquakes, but also by
landslides, volcanic eruptions, and
comet or meteorite impacts in the
ocean.

Why are Tsunamis

Dangerous?

As the tsunami crosses the deep
ocean, it may be only a few feet or
less in height. As the tsunami
approaches the shore, the wave
height increases and associated
currents intensify, becoming a threat
to life and property. There is usually
little time to forecast the severity of
a tsunami after one is generated.
Large areas of coastline can be
inundated by a tsunami.

A Tsunami:

YM is like a fast rising flood or an
advancing wall of water and strikes
with devastating force.

V moves faster than you can run.

V isa series of waves that may
continue for hours. The first wave
may not be the last or the most
dangerous.

Warning Signs of a Tsunami:

Vv A strong earthquake, felt ina
coastal area, that causes difficulty
standing.

V Asudden unexpected rise or fall
of the ocean tide or height.

V Aloud, roaring sound (like an
airplane or train) coming from the
ocean.

What do | do if | See
These Warning Signs?
V Keep calm.

V Immediately move to higher
ground or into a tall, sturdy
building and stay there.

V Do not drive — keep roads open
for emergency vehicles.

V Stay away from the beach until
Officials issue an “all clear.”

Who is at Risk for a Tsunami?

v Any resident, visitor, business or
facility on any beach or coastline

How a Tsunami Works

The most common causes of tsunamis are underwater landslides and earthquakes.

Here’s how an underwater earthquake can cause a tsunami:

@ An underwater earthquake occurs when a plate shifts
abruptly and pushes water upward with tremendous force.

(2) Low and fast waves are generated in all directions across
the ocean, some speeding as fast as 600 m.p.h.

6 As waves enter shallower water, they are
compressed, their speed slows, and
they build in height.

sancti

ed uP
water push

snéight increases and

nts intensify becoming
arty. ‘

Facts About Tsunamis

W Not every earthquake will
generate a tsunami.

V Asmall tsunami at one beach may
be a giant tsunami a few miles away.

Y Atsunami can strike anywhere and at
anytime along the U.S. coastline.

V The only warning you may have is
an earthquake.

W Tsunamis can reach the coast within
minutes of an earthquake.