it will be very useful to know more about tsunami!!

6. Tsunami is a Japanese word meaning ‘harbor
wave’. It is constituted with two syllables, Japanese
language meaning harbour ("tsu", 津) and wave
("nami", 波).
Tsunami is a wave train or series of waves
generated, by impulsive disturbance that vertically
displaces the water column, in water body.
Earthquake, landslides, volcanic eruption, explosion
and even the impact of cosmic bodies like
meteorites commonly generate tsunami. Tsunami
savagely attacks coastlines causing devastating
property damage and loss of lives.

7. • First tsunami was recorded in 1480 B.C. in eastern
Mediterranean, when the Minoan civilization was waped
out.
• A large tsunami accompanied by the earthquake of Lisbon
in 1755.
• North and South American records have dated such
events back to 1788 for Alaska and 1562 for Chile.
Records of Hawaiian tsunami go back to 1821.
• Tsunami hits the Mona Passage off Puerto Rico in 1918,
grand banks of Canada in 1929.

8. • First tsunami was recorded in 1480 B.C. in
eastern Mediterranean, when the Minoan
civilization was waped out.
• A large tsunami accompanied by the earthquake
of Lisbon in 1755.
• North and South American records have dated
such events back to 1788 for Alaska and 1562 for
Chile. Records of Hawaiian tsunami go back to
1821.
• Tsunami hits the Mona Passage off Puerto Rico in
1918, grand banks of Canada in 1929.

9. Many people have the mistaken belief that tsunamis are
single waves. They are not. Instead tsunamis are "wave
trains" consisting of multiple waves. The chart below is a
tidal gauge record from Onagawa, Japan beginning at the
time of the 1960 Chile earthquake. Time is plotted along the
horizontal axis and water level is plotted on the vertical axis.
Note the normal rise and fall of the ocean surface, caused by
tides, during the early part of this record. Then recorded are
a few waves a little larger than normal followed by several
much larger waves. In many tsunami events the shoreline is
pounded by repeated large waves.

11.  Volcanic eruptions
 Icefalls
 Heavy rainfall
 Seismic activities
 Submarine landslides
 Cosmic impacts

12.  Volcanic eruptions and icefalls create
disturbance in water and generate
tsunami.
 Heavy rainfall cause overflow of
water and generate tsunamis.

13.  .Tsunami can be generated when the see floor
abruptly deforms and vertically displaces the
overlying water.
 .Tectonic earthquakes are a particular kind of
earthquake that are associated with the earth’s
crustal deformation, when these earthquakes
occur beneath the see, the water above the
deformed area is displayed from its
equilibrium position.
 .Waves are formed as the displaced water mass,
which acts under the influence of gravity,
attempts to regain its equilibrium

14.  Ocean waves are normally divided into 3 groups,
characterized by depth:
• Deep water
• Intermediate water
• Shallow water
 Even though a tsunami is generated in deep
water (around 4000 m below mean sea level),
tsunami waves are considered shallow-water
waves. As the tsunami wave approaches the
shallow waters of shore, its time period remains
the same, but its wavelength decreases rapidly,
thus causing the water to pile up to form
tremendous crests, in an effect known as
"shoaling".

15. Most tsunamis are caused by earthquakes
generated in a seduction zone, an area where
an oceanic plate is being forced down into
the mantle by plate tectonic forces. The
friction between the sub ducting plate and the
overriding plate is enormous.
This friction prevents a slow and steady
rate of seduction and instead the two plates
become "stuck".

16.  As the stuck plate continues to
descend into the mantle .
 The motion causes a slow distortion
of the overriding plage.
 The result is an accumulation of
energy very similar to the energy
stored in a compressed spring.
Energy can accumulate in the
overriding plate over a long period of
time - decades or even centuries.

17. Tsunamis occur most frequently in the Pacific Ocean, but
are
a global phenomenon; they are possible wherever large
bodies of
water are found, including inland lakes, where they can
be caused
by landslides.
Japan is a nation with the most recorded tsunamis in the
world. The earliest recorded disaster being that of the 684
A.D.

18. .Tsunami is one of the earth’s disaster. It was a Japanese
word
meaning “harbor wave,” used as the scientific term for a
class
of abnormal sea wave that can cause catastrophic
damage when it hits a coastline.
.Tsunamis can be generated by an undersea earthquake,
an undersea landslide, the eruption of an undersea volcano,
or by the force of an asteroid crashing into the ocean.

19.  The earthquake that caused the Sumatran tsunami
is the second largest to ever be recorded on a
seismograph.
 The magnitude of the earthquake was 9.3 on the
Richter scale.
 This earthquake had the longest duration, that is
lasted for the longest amount of time, ever
observed, lasting approximately 10 minutes.
 It caused the entire planet to vibrate by as much
as 1 cm (0.5 inches), and triggered other
earthquakes as far away as Alaska.

20.  There were no Tsunami Warning Systems in
the Indian Ocean on the 26th December
2004. Had there had been, many lives
could have been saved.
 A 10 year old tourist named Tilly Smith, who
had studied tsunamis at school, noticed the
receding tide and frothing bubbles, and
told her parents there was going to be a
tsunami. Her parents told the rest of the
beach and everyone was evacuated
safely.

22. A Tsunami is generated when a large
amount of water is displaced which is
done-:
 Mainly By The Earthquakes.
 By The Landslides.
 By Volcanic Eruptions.
 By Impact Events like Meteorite impacts

23.  The Sea floor abruptly
deforms and displaces
the sea water lying
above.
 Large vertical
movements of earth's
crust can occur at
plate boundaries
which are called
“faults”.

24.  Tsunamis may reach a maximum
vertical height onshore above sea
level, often called a run up height, of
10, 20, and even 30 meters.
 For a typical ocean Depth of 4000m,
a tsunami moves with a speed about
700km/hr.
 The fast-moving water associated
with the inundating tsunami can
crush homes and other coastal
structures.

27.  Often no advance
warning of an
approaching Tsunami
 An earthquake felt
near a body of water
may be considered
an indication that a
tsunami will shortly
follow.

28.  Tsunami death toll
tops 118,000.
 Around 10,000 killed in
India.
 In Thailand, more than
4,000 are feared
dead and dozens of
deaths are reported in
Malaysia, Myanmar
and Maldives.
 WHO estimates five
million people are
without basic needs.

29. Calong, A land of 13,000 “
vaporized” by Tsunami

30. The Tsunami
That Struck
Thailand
On
December 26, 2004

31.  Donations done under
the Prime Minister Relief
Fund.
 Rice, mats, medicines
were provided.
 ITC distributed over 1
lakh shirts to the victims.
 New houses were
provided.

32.  Responded to the
emergency in hours.
 Building enough homes to
accommodate five
families a week.
 Highly successful because
of the close and constant
involvement of the
affected communities.
 Still working for the
betterment of the victims.

33.  Early warnings come
from the nearby
animals as they sense
danger and flee to
higher grounds.
 Tsunami walls for the
reduction in the
damage.
 Tsunami warning system
alert the people before
the wave reaches the
shore

34.  Loss of life and property can be reduced by
proper planning.
 Tsunami warnings can be made to aware
peoples.
 Stay away from all low lying coastal areas.
 Never go down to the shore to watch
tsunami.
 Stay out of low lying danger areas until an
“all-clear” is issued by competent authority.