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| First Wave |
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| Looks like a normal beach wave |
Pictures Source:
A tsunami consists of a series of waves created by a body of water like
an ocean. The most popular cause of a Tsunami are usually earthquakes, volcanoes, mass movements below and above water, underwater
explosions, and landslides. Again we are dealing with plate tectonics and the energy released in the earth's
crust. It is eather a compressional, tensional or shear stress. Tsunami's can result in minor damage or devasting
loss.
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| Second wave to hit land |
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| Getting a little too close |
how the "tidal wave" is created:
A Tsunami can be generated when the plate boundaries are moved and the sea floor falls or rises and then the water returns
to sea level starts up some low waves were they rapidly spread ocean wide. Most Tsunamis are generated and associated to an
earthquake at the subsuction zone because the vertical movement of the sea floor is the most conductive to the forming of
a tsunami.
Signs of a Tsunami
Since earthquakes often cause these Tsunami's, when an earthquake is felt, you can almost be sure there will be a Tsunami
followed, therefore you could get out of the water and prepare yourself for one of these huge waves.
Warnings and Preventions
Although a Tsunami could not be prevent you could at least be prepared for one. Move away from the shore
for number one. Also,using a loud warning system to detect and announce Tsnuami is a good way to tell people to go to a safer
place before that wave reaches land. The buliding of strong Tsunami walls is another step taken to prevent damage,and floodgates
and channels are built to redirect the water. Although, sometimes the gates or walls serve no purpose because the waves
could be much much higher then these barrier walls. DL Johnson notes that one of the most important and primary
messangers of a natural hazard such as the Tsunamis are "NOAA" which stands for "National Oceanic and Atmospheric
Administration", says Johnson. Johnson also mentions that NOAA are important in observing and researching
Tsunami.( http://tsunami.noaa.gov/).
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| Third wave in the series |
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| Reaches the housewhich is way too close. Imagine the fourth wave! |
The authors of Physical Geology & the Enviroment, describe the waves speed and measurment
of a large wind-generated wave to have a wavelenght of 400 m and move in the deep water at a speed of 90 km per hour
and in the middle of a hurricane a wave could have a height of 15 m high.( Plummer, McGeary,Carlson, Eyles, Eyles, Physical
Geology & the Enviroment, 1st Edition, 2004, Mc-Graw Hill University Ryerson Limited, pg.90).
In the textbook Physical Geology & the Enviroment, 1st Canadian Edition, I learned
from the authors that during a hurricane the wavelenght could be 160 km and be moving as fast as 725 km per hour but
in deep waters the waveheight maybe small compared to when it reaches shore.
What causes the great waves to get big ashore is by the bottom of the seafloor. According to Plummer,
McGeary, Carlson, and Eyles, "only a few localities have a combination of gently sloping offshore shelf and funnel- shaped
bay that foces tsnuamis so amazing heights, where the record height is 85 m in 1971in the Ryukyu islands south of Japan."
(Plummer, McGeary,Carlson, Eyles, Eyles, Physical Geology & the Enviroment, 1st Edition, 2004, Mc-Graw Hill University
Ryerson Limited, pg.90).
Tsunamis are described as shallow-water waves which are different from the wind- generated waves
we often see for example, Lake nipissing's large waves on a windy day.
Bigger waves can flood land covering 1,000 feet of land and then sucking back debris and
even people caught in the wave and bringing them into the wide open ocean.
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