what are the causes for tsunami happens?

Answer 1

A Tsunami can be generated when the sea floor abruptly deforms and vertically displaces the overlying water. Such large vertical movements of the Earth’s crust can occur at plate boundaries. Subduction earthquakes are particularly effective in generating tsunami.

Submarine landslides (which are sometimes triggered by large earthquakes) as well as collapses of volcanic edifices may also disturb the overlying water column as sediment and rocks slide downslope and are redistributed across the sea floor. Similarly, a violent submarine volcanic eruption can uplift the water column and form a tsunami.

Tsunami's are surface gravity waves that are formed as the displaced water mass moves under the influence of gravity and radiates across the ocean like ripples on a pond.

In the 1950s it was discovered that larger tsunami than previously believed possible could be caused by landslides, explosive volcanic action, and impact events when they contact water. These phenomena rapidly displace large volumes of water, as energy from falling debris or expansion is transferred to the water into which the debris falls. Tsunami caused by these mechanisms, unlike the ocean-wide tsunami caused by some earthquakes, generally dissipate quickly and rarely affect coastlines distant from the source due to the small area of sea affected. These events can give rise to much larger local shock waves (solitons), such as the landslide at the head of Lituya Bay which produced a water wave estimated at 50 – 150 m and reached 524 m up local mountains. However, an extremely large landslide could generate a “megatsunami” that might have ocean-wide impacts.

The geological record tells us that there have been massive tsunami in Earth's past. These tsunami were so large that they caused landslides on the opposite coast triggering another massive tsunami, or "bounce back" tsunami. An example today would be a landslide equivalent to everything west of Portland, Oregon falling into the Pacific Ocean, resulting in a tsunami that would then hit the Chinese coast with enough force to erode the coast, triggering a landslide large enough to send a tsunami that would in turn inundate the U.S. West Coast and would wipe out Portland.

Answer 2

Tsunami Geology - What Causes a Tsunami?

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What causes a tsunami?.
.. A tsunami is a large ocean wave that is caused by sudden motion on the ocean floor. This sudden motion could be an earthquake, a powerful volcanic eruption, or an underwater landslide. The impact of a large meteorite could also cause a tsunami. Tsunamis travel across the open ocean at great speeds and build into large deadly waves in the shallow water of a shoreline.

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 "stuck".
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 time - decades or even centuries.

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 overlying water. At the same time, inland areas of the overriding plate are suddenly lowered.

Tsunami Races Away From the Epicenter
The moving wave begins travelling out from where the earthquake has occurred. Some of the water travels out and across the ocean basin, and, at the same time, water rushes landward to flood the recently lowered shoreline.
Tsunamis Travel Rapidly Across Ocean Basis
Tsunamis travel swiftly across the open ocean. The map below shows how a tsunami produced by an earthquake along the coast of Chile in 1960 traveled across the Pacific Ocean, reaching Hawaii in about 15 hours and Japan in less than 24 hours.
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.

Answer 3

Causes for tsunamis:

1. Earthquakes on the sea floor.
2. Volcanic eruptions.
3. Underwater landslides.

Answer 4

The causes for a tsunami to happen is the cause of the earth's movements. The earth's plate (crust) is moving thus creating a fiction to the other earth's plates. Sometimes when this friction is too hard, it could trigger a tsunami..

Answer 5

Causes of tsunami:
-Earthquakes
-Undersea volcanoes
-Falling of a large meteorite may also cause tsunami; just like when a pebble is thrown in water ripples are created.
-If a huge bomb is dropped on the sea near the coast.

Answer 6

A tsunami is generally caused due to the following:
1.derwater earthuakes
2.derwater volcanic eruptions
3.derwater landslides
4.movement of the tectonic plates
5.large meteoric impacts
6.testing of nuclear weapons in the ocean

Answer 7

Tsumami's are most likely going to be caused by 3 things:
1. Earthquakes
2. Falling land-large mass of land sliding off.
3. Objects from space hitting the earth.

Answer 8

Fill a bathtub and place a flat board half way to the bottom. Shove it violently down. That's a plate of earth , slipping down, not side-to side like other slippages. The force generates a rolling motion of water that crawls inland because of its velocity. In mid ocean it isn't noticed because the motion is horizontal, not verticle.

Answer 9

fairly plenty onyl 3 issues: a million: Earthquakes (many times led to by ability of clashing of tectonic plates). 2: super products, like say a bite of rock on the area of a cliff, falling into the water. it might must be truly a huge bite nevertheless. 3: gravitational forces, like an quite super merchandise passing very close to to the Earth (yet no longer impacting). thus, the article could must be correct to the dimensions of the moon, and could desire to be closer and shifting quicker than our moon presently is.

Answer 10

Earthquakes