Transcript tsunamiDescription

Sponsoring Teacher: Ismi Kamarul Sham b. Ismail
Sponsor School: Batu 4 Secondary School
City: Gerik, Perak
Country: Malaysia
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Objective
Introduction
Conclusion
Web References
Project’s Member
Tsunami Description can give a right definition of tsunami,
to know the cause of tsunami and where do tsunami occur on
our planet.
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Objective
Introduction
Conclusion
Web References
Project’s Member
Tsunami
Description :
1. Definition of Tsunami
2.
What causes of Tsunami?
3.
Where do tsunamis occurs in the world
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What is a tsunami ?
What causes a tsunami ?
Where do tsunamis occur ?
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.
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What is a tsunami ?
What causes a tsunami ?
Where do tsunamis occur ?
Tsunami "Wave Train"
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.
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What is a tsunami ?
What causes a tsunami ?
Where do tsunamis occur ?
1. Tsunami can be generated when
the see floor abruptly deforms
and vertically displaces the
overlying water.
2. 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.
3. Waves are formed as the
displaced water mass, which acts
under the influence of gravity,
attempts to regain its equilibrium
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What is a tsunami ?
What causes a tsunami ?
Where do tsunamis occur ?
• 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".
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What is a tsunami ?
What causes a tsunami ?
Where do tsunamis occur ?
Subduction Zones are Potential Tsunami Locations
Most tsunamis are caused by earthquakes generated
in a
subduction zone, an area where an oceanic plate is
being
forced down into the mantle by plate tectonic forces.
The
friction between the subducting plate and the
overriding
plate is enormous. This friction prevents a slow and
steady
rate of subduction and instead the two plates become
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What is a tsunami ?
What causes a tsunami ?
Where do tsunamis occur ?
Accumulated Seismic Energy
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
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What is a tsunami ?
What causes a tsunami ?
Where do tsunamis occur ?
Earthquake Causes Tsunami
Energy accumulates in the overriding plate until it
exceeds
the frictional forces between the two stuck plates.
When
this happens, the overriding plate snaps back into an
unrestrained position. This sudden motion is the
cause of
the tsunami - because it gives an enormous shove to
the
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What is a tsunami ?
What causes a tsunami ?
Where do tsunamis occur ?
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.
Please refer to the below website of the List of historic
tsunamis by death toll
http://en.wikipedia.org/wiki/List_of_natural_disasters_by_death_t
oll
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What is a tsunami ?
What causes a tsunami ?
Where do tsunamis occur ?
Map of tectonic plates where the earthquake triggered the tsunami
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Objective
Introduction
Conclusion
Web References
Project’s Member
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.
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Objective
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Introduction
Conclusion
Web References
Project’s Member
http://www.rumela.com/diary/diary_tsunami.htm
http://encarta.msn.com/encyclopedia_761559898/Tsunami.html
http://en.wikipedia.org/wiki/Tsunami
http://geo-world.org/tsunami/
http://geology.com/articles/tsunami-geology.shtml
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Objective
Introduction
Conclusion
Web References
Project’s Member
ISMI KAMARUL SHAM B. ISMAIL
[email protected]
SITI HAWA BT. MOHD RAZALI
[email protected]
NURUL ASHIKIN BT. HAMZAH
[email protected]
NOR ATIQAH BT. MOHD RAHIMI
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