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Sponsoring Teacher: Ismi Kamarul Sham b. IsmailSponsor School: Batu 4 Secondary SchoolCity: 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,Tsunami Description can give a right definition of tsunami,to know the cause of tsunami and where do tsunami occur on to know the cause of tsunami and where do tsunami occur on our planet. our planet.
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Tsunami Tsunami Description :Description :
1.1. Definition of TsunamiDefinition of Tsunami2.2. What causes of Tsunami?What causes of Tsunami?3.3. Where do tsunamis occurs in the Where do tsunamis occurs in the
worldworld
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What is a tsunami ? What causes a tsunami ? Where do tsunamis occur ?
Tsunami is a Japanese word meaning ‘Tsunami is a Japanese word meaning ‘harbor harbor wavewave’. It is constituted with two syllables, ’. It is constituted with two syllables, Japanese language meaning harbour ("tsu", Japanese language meaning harbour ("tsu", 津津 ) and ) and wave ("nami", ("nami", 波波 ).).
Tsunami is a wave train or series of waves Tsunami is a wave train or series of waves generated, by impulsive disturbance that generated, by impulsive disturbance that vertically displaces the water column, in vertically displaces the water column, in water body. Earthquake, landslides, volcanic water body. Earthquake, landslides, volcanic eruption, explosion and even the impact of eruption, explosion and even the impact of cosmic bodies like meteorites commonly cosmic bodies like meteorites commonly generate tsunami. Tsunami savagely attacks generate tsunami. Tsunami savagely attacks coastlines causing devastating property coastlines causing devastating property damage and loss of lives.damage and loss of lives.
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What is a tsunami ? What causes a tsunami ? Where do tsunamis occur ?
Tsunami "Wave Train"Tsunami "Wave Train"Many people have the mistaken belief that tsunamis are Many people have the mistaken belief that tsunamis are single waves. They are not. Instead tsunamis are "wave single waves. They are not. Instead tsunamis are "wave trains" consisting of multiple waves. The chart below is a trains" consisting of multiple waves. The chart below is a tidal gauge record from Onagawa, Japan beginning at tidal gauge record from Onagawa, Japan beginning at the time of the 1960 Chile earthquake. Time is plotted the time of the 1960 Chile earthquake. Time is plotted along the horizontal axis and water level is plotted on along the horizontal axis and water level is plotted on the vertical axis. Note the normal rise and fall of the the vertical axis. Note the normal rise and fall of the ocean surface, caused by tides, during the early part of ocean surface, caused by tides, during the early part of this record. Then recorded are a few waves a little larger this record. Then recorded are a few waves a little larger than normal followed by several much larger waves. In than normal followed by several much larger waves. In many tsunami events the shoreline is pounded by many tsunami events the shoreline is pounded by repeated large waves.repeated large waves.
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What is a tsunami ? What causes a tsunami ? Where do tsunamis occur ?1.1. Tsunami can be Tsunami can be generated when the see floor abruptly when the see floor abruptly deforms and vertically deforms and vertically displaces the overlying displaces the overlying water. water.
2.2. Tectonic earthquakes are a Tectonic earthquakes are a particular kind of particular kind of earthquake that are earthquake that are associated with the earth’s associated with the earth’s crustal deformation, when crustal deformation, when these earthquakes occur these earthquakes occur beneath the see, the water beneath the see, the water above the deformed area is above the deformed area is displayed from its displayed from its equilibrium position. equilibrium position.
3.3. Waves are formed as the Waves are formed as the displaced water mass, displaced water mass, which acts under the which acts under the influence of gravity, influence of gravity, attempts to regain its attempts to regain its equilibrium equilibrium
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What is a tsunami ? What causes a tsunami ? Where do tsunamis occur ?• Ocean waves are normally Ocean waves are normally
divided into 3 groups, divided into 3 groups, characterized by depth:characterized by depth:
• •• Deep water Deep water • •• Intermediate water Intermediate water • •• Shallow water Shallow water • Even though a tsunami is Even though a tsunami is
generated in deep water generated in deep water (around 4000 m below mean (around 4000 m below mean sea level), tsunami waves sea level), tsunami waves are considered shallow-are considered shallow-water waves. As the water waves. As the tsunami wave approaches tsunami wave approaches the shallow waters of shore, the shallow waters of shore, its time period remains the its time period remains the same, but its wavelength same, but its wavelength decreases rapidly, thus decreases rapidly, thus causing the water to pile up causing the water to pile up to form tremendous crests, to form tremendous crests, in an effect known as in an effect known as "shoaling"."shoaling".
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What is a tsunami ? What causes a tsunami ? Where do tsunamis occur ?
Most tsunamis are caused by earthquakes Most tsunamis are caused by earthquakes generated in a generated in a
subduction zone, an area where an oceanic subduction zone, an area where an oceanic plate is being plate is being
forced down into the mantle by plate tectonic forced down into the mantle by plate tectonic forces. The forces. The
friction between the subducting plate and the friction between the subducting plate and the overriding overriding
plate is enormous. This friction prevents a plate is enormous. This friction prevents a slow and steady slow and steady
rate of subduction and instead the two plates rate of subduction and instead the two plates become become
"stuck". "stuck".
Subduction Zones are Potential Tsunami Locations
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What is a tsunami ? What causes a tsunami ? Where do tsunamis occur ?
As the stuck plate continues to descend into As the stuck plate continues to descend into the mantle the mantle
the motion causes a slow distortion of the the motion causes a slow distortion of the overriding plage. overriding plage.
The result is an accumulation of energy very The result is an accumulation of energy very similar to the similar to the
energy stored in a compressed spring. Energy energy stored in a compressed spring. Energy can can
accumulate in the overriding plate over a long accumulate in the overriding plate over a long period of period of
time - decades or even centuries.time - decades or even centuries.
Accumulated Seismic Energy
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What is a tsunami ? What causes a tsunami ? Where do tsunamis occur ?
Energy accumulates in the overriding plate Energy accumulates in the overriding plate until it exceeds until it exceeds
the frictional forces between the two stuck the frictional forces between the two stuck plates. When plates. When
this happens, the overriding plate snaps back this happens, the overriding plate snaps back into an into an
unrestrained position. This sudden motion is unrestrained position. This sudden motion is the cause of the cause of
the tsunami - because it gives an enormous the tsunami - because it gives an enormous shove to the shove to the
overlying water. At the same time, inland overlying water. At the same time, inland areas of the areas of the
overriding plate are suddenly lowered. overriding plate are suddenly lowered.
Earthquake Causes Tsunami
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What is a tsunami ? What causes a tsunami ? Where do tsunamis occur ?Tsunamis occur most frequently in the Tsunamis occur most frequently in the Pacific Ocean, but are , but are
a global phenomenon; they are possible wherever a global phenomenon; they are possible wherever large bodies of large bodies of
water are found, including inland lakes, where they water are found, including inland lakes, where they can be caused can be caused
by landslides. by landslides. Japan is a nation with the most recorded Japan is a nation with the most recorded tsunamis in the tsunamis in the
world. The earliest recorded disaster being that of world. The earliest recorded disaster being that of the 684 A.D. the 684 A.D. Please refer to the below website of the List of Please refer to the below website of the List of historic historic
tsunamis by death tolltsunamis by death toll
http://en.wikipedia.org/wiki/http://en.wikipedia.org/wiki/List_of_natural_disasters_by_death_tollList_of_natural_disasters_by_death_toll
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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 tsunamiMap of tectonic plates where the earthquake triggered the tsunami
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Tsunami is one of the earth’s disaster. It was a Japanese word Tsunami is one of the earth’s disaster. It was a Japanese word meaning “harbor wave,” used as the scientific term for a class meaning “harbor wave,” used as the scientific term for a class of abnormal sea wave that can cause catastrophic damage when of abnormal sea wave that can cause catastrophic damage when it hits a coastline. it hits a coastline. Tsunamis can be generated by an undersea earthquake, Tsunamis can be generated by an undersea earthquake, an undersea landslide, the eruption of an undersea volcano, an undersea landslide, the eruption of an undersea volcano, or by the force of an asteroid crashing into the ocean. or by the force of an asteroid crashing into the ocean.
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1. http://www.rumela.com/diary/diary_tsunami.htm2. http://encarta.msn.com/encyclopedia_761559898/Tsunami.h
tml3. http://en.wikipedia.org/wiki/Tsunami4. http://geo-world.org/tsunami/5. http://geology.com/articles/tsunami-geology.shtml
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ISMI KAMARUL SHAM B. ISMAIL
NURUL ASHIKIN BT. HAMZAH
[email protected] ATIQAH BT. MOHD RAHIMI
SITI HAWA BT. MOHD RAZALI
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