FACTS ABOUT TSUNAMI !

Skrg nih..ble bce srt khabar..on9, dgr radio..msti eboh berita psl TSUNAMI kt jepun yg bru jd 11hb lpas.. ngn gmpa bumi 8.9 SR.. eisshhhh . gle x kuat ? mau trauma sminggu klu ak yg de kt tmpt kjadian :D tp papepon, ak ksian sgt ngn pe yg da jd..nk wt cmne kn.. da ketentuan Allah..

cmni la rupanyer umh2 kt cne yg da kna hanyutkn

tgok..byk kreta yg tggelam..

n ni la k'adaan Jepun skrg..byk umh yg da musnah terok :(

Btw, kte ni yg idop n slamat lg ni kna la tlg bg sumbangn kt org2 kt JEPUN sana tuh.... sharing is caring, ryte ? haha . Ha..ni de some facts about tsunami yg ak nk share kt korang :)

Tsunami is a Japanese word. "Tsu" translates to harbor and "nami" to wave. When a body of water is rapidly displaced, a series of waves are created. These series of waves are called "tsunami". These waves are usually 10 meters high. The rapid displacement of the body of water takes place due to the following reasons:

• volcanic eruptions
• earthquakes
• underwater explosions
• large meteorite impacts
• mass movements above or under water
• nuclear weapons testing in seas     

Beginning of a tsunami wave
Sometimes plate boundaries abruptly deform and displace the overlying water vertically. Subduction earthquakes are efficient in generating a tsunami. In the 1940s, an earthquake measuring 7.8 on the Richter scale gave rise to a tsunami. Explosive volcanic action, landslides and impact events can also start a tsunami. The water wave may reach 50 to 150 meters and cover a height of 500 meters on local mountains. A "megatsunami" is caused by large landslides. The displaced water mass moves under the effect of gravity. This water radiates across the ocean similar to ripples in a pond.

Signs that a tsunami is approaching

• if an earthquake takes place near a body of water, it means that a tsunami will follow in a short time
• if the water along the shoreline recedes dramatically and exposes usually submerged areas it should be inferred that this is the trough of the tsunami and a crest will follow after a few seconds or minutes
• some large animals like elephants hear the noise of the tsunami and move in the opposite direction towards inland
• computer models can also foresee tsunami arrival and impact depending upon knowledge of the event that caused it and the shape of the oceanbed
• there is a loud roar similar to a train or aircraft

Tsunami warning system
Such systems comprise of two parts:

• a network of sensors to detect tsunamis
• a communications infrastructure to provide alarms for evacuation of coastal areas

There exist international and regional tsunami warning systems. The underlying principle used in both is that tsunamis move at a speed of 0.14 to 0.28 km/sec while seismic waves of 4 km/sec. Thus, when an earthquake is confirmed, there is sufficient time to predict a tsunami.

Reducing the effect of a tsunami

• Japan builds tsunami walls of 4.5 meters height in populated coastal areas
• floodgates and channels are built to redirect the water from the tsunami
• a tree cover is made on the shore

These measures slow down and moderates a tsunami. However, they cannot totally prevent the destruction and loss of life.

Other tsunami facts
At the deepest point in the ocean, Tsunamis can have a speed of 600 mph. Close to the shore, this speed reduces to 30 to 40 mph. This energy of the wave's speed is transformed to increased height and sheer force. These waves can be as long as 100 kilometers and one hour apart. They can cross huge oceans without much loss of energy. Tsunamis can take place at any time in night or day. They can move up the rivers and streams that end up in the ocean. Tsunamis move faster than a human being.

Megatsunami
If the waves range from 40 meters to more than 100 meters, they are called as a "megatsunami". When they reach land, they acquire more height due to the force of impact. They are also called as "iminami" or "wave of purification".