what is a tsunami?

Answer 1

Hey there, im a marine scientist and sometimes I can go on and on about this kind of stuff, but stick with me. If you get sick of me just delete me or something :)

The most common cause of tsunamis are earthquakes that occur on the ocean floor. Often these quakes occur at boundary lines where tectonic or continental plates meet. These are known as convergent plates. When the plates push against each other, pressure builds over time until a critical point is reached. The plates slip and thrust past each other lifting or dropping the seabed floor. This process is known as subduction. In the process the displaced water rushes outward in a 360-degree circular pattern forming a series of radiating waves like enormous ripples just like when you through a stone in a lake.

Though a tsunami in open ocean rarely reaches higher than a few feet it is a very deep wave packing lots of power, making it significantly different from surface disturbances, like true ripples or wind-generated waves. A tsunami crest can be a1000 kilometers long, but because the height is minimal it usually cannot be detected in open ocean, you can be on a fishing boat and it can go right by you and you won't even notice. As it moves outwards it can travel as fast as a passenger jet at (724 - 965 kph) racing towards shores hundreds or even thousands of miles away.

As it approaches shore and depth decreases the tsunami will slow but the power it contains continues to roll forward increasing amplitude or height. Waves can rise 100 feet (30 meters) but more often its arrival is much more subtle. The ocean may draw back from the shore so far that it disappears from view before it starts flowing back in, not as a wave at first but more like a bathtub quickly rising.

Within seconds the water level can rise 30, 60, even 100 feet (up to 30 meters) above sea level, becoming a rushing wall of water moving up to 64 kph (40mph) overtaking and lifting everything in its path. The force can easily crush homes or other structures, carry off vehicles, uproot trees and flood low-laying coastal areas up to 1.6 kilometers (1mile) inland.

Hope this helped a bit. Sorry its a bit long :)

Answer 2

Visit my slide show to know more on Tsunami. I am the man issued the warning 2 hours before it strikes our Indian coast. The reasons are that day was full moon day,usually the seismic activity will be more on that day and I sensed the earthquake wave for an unbelievable time of 12 minutes with the use of my quake alarm, The book I read during my stay in USA written By Mr Bruce Bolt clearly says move away from sea shore because the Tsunami may strike long after the shaking is stoped. I spoke about Tsunami in Singapore radio 9 months before it struck our Indian coast. But my warning was ignored. My Community in Orkut
http://www.orkut.com/Community.aspx?cmm=26068261
Presentation slides
http://asia.pg.photos.yahoo.com/ph/quake

Answer 3

A tsunami is simply the shifting of earth plates(earthquake) on the seabed, which results in large and mostly fatal waves.

Answer 4

a huge wave in the ocean, caused by underwater disturbances, such as earthquakes or volcanic eruptions. They are NOT tidal waves, as they are sometime mistakenly called.
(A tidal wave is the crest of a tide as it moves around the Earth. These are caused by the natural gravitational pull of the sun and moon as opposed to ocean surface waves which are caused by wind friction on the surface of the water.)

http://www.fema.gov/hazard/tsunami/index.shtm

Answer 5

it is so divesting what's occurred in Japan, I sorta choose I have been there, for the reason that I even have kin lacking, interior the wellbeing facility, homeless, or in shelters, and that i understand of a chum who has died already. Even seeing pictures of it makes me crushed that i exploit to stay there and It completely have been given destroyed. The no longer common section approximately it fairly is i'm no longer able to get ahold of individuals in japan because of the fact the provider is tousled.... i'm hoping issues clean up. and that i admire your poem! Nature has some mysterious techniques....

Answer 6

♡*•.♡ a large destructive ocean wave caused by an underwater earthquake or some other movement of the earth’s surface. ♡*•.♡

Answer 7

when a earthquake occurs in a ocean then it led to high tides that r called tsunami

Answer 8

A giant wave that is cosed by an earthquake or affluence.

Answer 9

A tidal wave.