Tsunami and Tidal Waves
By Matt Sapp
&
Lauren Gareau
Wading in Water
 Tsunami, commonly known
as Tidal Waves come from
the Japanese word Tsu for
(harbor) Nami for (Wave)
 All oceans can have
tsunami’s but 80% of
Tsunami’s originate in the
Pacific Ocean due to large
amounts of geological
activity
 From Japan to the West
Coast of South America,
tsunami’s strike with
devastating consequences
All Washed Up
 A tsunami is a series of waves
in a body of water that vertically
displaces the water column
 Oceanographers often refer to
tsunami’s as seismic sea waves
as a result of a rise or fall of the
earths crust
 The displacement can be
caused by earthquakes,
landslides, volcanic eruptions,
and meteorites
 All but meteorites occur under
the sea
 Tsunami’s are most likely to
occur in April
Turning the Tide
 Tsunami’s can go undetected
until it reaches shallow waters
 Some vary from 30ft to 100ft
 Tsunami’s move a the speeds
approaching jet aircraft
 Tsunami’s are able to be
detected but the size and
destructive force of them can
not be predicted
 The ability to detect them gives
the population a chance to get
cover
A Wave is a Wave?
 The difference between a
tsunami and wave is that
waves you see at the
beach are generated by
wind
 Waves depend on the
strength of the wind and
the wavelengths (distance
between crest/trough) is
from 5ft to 1000ft
 Waves moves at about 5
to 60 mph
A Wave is A Wave Cont
 Tsunami’s result from
physical mechanisms
 The magnitude of a
tsunami is by the
mechanism
 The difference between
wavelengths can range
from 100-300 miles apart
 Depending on depth
tsunami’s can travel up to
500 mph
That’s No Tsunami
 Common misconceptions come
regarding tsunami’s appearance
but it all depends on the
topography of the ocean floor
 The increase in height occurs as
the tsunami gets closer to land
 Most think tsunami’s are large
steep waves this is not always
the case
 Most tsunami’s appear as an
advancing tide
 The result is the rapid flooding
of the low-lying coastal areas
That’s a big Momma
 The largest tsunami occurred in
Lituya Bay on the southern
coast of Alaska
 On July 9, 1958 a earthquake
caused a glacier landslide at the
head of the bay
 It triggered a wave that was
1720ft/524m high
 This is the equivalent of over 5
football fields
 This is the case of a tsunami
where no people were present
but this possible
 Up to 36,000 people have died
in a tsunami and the following
flooding that occurs (Krakatoa,
Indonesia 1883)
Danger Watch Yourself
 A tsunami can reach the
shore of any country
regardless of where it
starts in about a day and if
local, it can reach in
minutes
 A tsunami is more than just
a single wave like an
earthquakes aftershocks,
tsunamis are a wave train
and many people have lost
their lives returning home
thinking it was safe
Crazy Pics
Questions
 1. What is a Tsunami?
 2. What is the ranging height for Tsunamis?
 3. What is the difference between a Tsunami
and a wave?
 4. Where and when did the largest Tsunami
occur?
 5. How long does it take for a Tsunami to
occur?