What are two causes of tsunamis? where are tsunamis higher: in the middle of the ocean or near shore? how fast do they travel?

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Tsunami are waves caused by sudden movement of the ocean due to earthquakes, landslides on the sea floor, land slumping into the ocean, large volcanic eruptions or meteorite impact in the ocean.


Ironically, in deep, open-ocean water, tsunami waves are often less than a meter high and can travel at speeds up to 1,000 kilometers per hour. However, as a tsunami wave approaches shallower waters along the coast, the leading edge of the wave begins to slow down while the rest of the wave begins to “pile up” behind it — causing it to grow in height while maintaining its strength

Where the ocean is over 6,000 meters (3.7 miles) deep, unnoticed tsunami waves can travel at the speed of a commercial jet plane, over 800 km per hour (500 miles per hour). Tsunamis travel much slower in shallower coastal waters where their wave heights begin to increase dramatically.