What Is A Tsunami?

Tsunami is Japanese for "harbor wave." It is, in fact, a series of waves which travel outward on the ocean surface in all directions in a kind of ripple effect.
A Tsunami is A very large ocean wave caused by an underwater earthquake or volcanic eruption.
A tsunami wave that can travel at speeds up to 600 mi/hr (965 km/hr), hundreds of miles over open sea before it hits land. Sometimes incorrectly called a tidal wave, a tsunami is usually caused by an earthquake, volcanic eruption or coastal landslide.
Don't forget to visit following Blurtit Question:
How do tsunami's occur?

If we just look into the past most of the death occurred within 1964 Alaskan earthquake, they were caused by seismic sea waves or in other words Tsunami. These waves which are so destructive in other words are also called as "Tidal waves" however it's just a fake name because these waves are not generated by tidal affects of moon. Tsunami start forming in the sea just like the ripple forms in the water when we drop or throw some pebble into it.

Tsunami waves travels with the speed of 500 to 800 kilometers per hour. Although tsunami has that characteristic but still it is not possible to detect it on early stage as in the start the height of the waves is even less then one meter. However when it enters into shallow sea water the waves those are destructive becomes slow down and then it start reaching the height up to 30 meters.

The greatest sign of tsunami is that water is rapid withdrawal of water from the coastal areas. So it's important for the people who are leaving in those areas that after observing that indication they better move to higher ground.

A big wave caused by an earthquake, a powerful volcanic eruption, or an underwater landslide

Tsunami is a word which is derived from the Japanese and is roughly translates as 'Harbour Wave'. It is a very specific phenomenon whereby extremely long wavelengths come ashore. Because the volume of water carried within the wavelengths is so enormous, once the water hits the land, havoc is wreaked. In addition, the wavelengths carry on over a sustained period of time. They can be generated by an exceptionally violent undersea disturbance or activity both in the ocean or near the coast.

Historically tsunami was called tidal wave or seismic waves. The term tidal wave was generally the non-scientific name, but this is inaccurate because tsunami is not tide related, they can be caused by an earthquake or by a meteorite landing etc.

Scientists used to refer to tsunamis as seismic sea waves, but this is also a misnomer because this would mean that a tsunami could only be caused by an earthquake, whereas this is not in fact the case.

Tsunami is a word which is derived from the Japanese and is roughly translates as 'Harbour Wave'. A tsunami is a huge ocean wave that can travel at speeds up to 600 mi/hr (965 km/hr), hundreds of miles over open sea before it hits land. It is a wave on or under ocean or sea caused by drastic movements above or under water like Earthquakes etc. Following are some of the reasons of Tsunami:
Volcanic eruptions and other underwater explosions,
landslides,
underwater earthquakes,
large asteroid impacts and detonation of nuclear weapons at sea.
Also Visit Tsunami Word Usage Examples and following Blurtit Questions:
What is a tsunami?
What is a tsunami and how is it related to a volcano?
What Causes A Tsunami?

A destructive, tidal wave, which wipes out everything in its path

A type of tidal wave usually caused by an underwater earthquake or volcanic eruptions .

A TSUNAMI IS a series of water waves that is caused by the displacement.

A huge tidal wave.

Underwater earthquake Is A Tsunami

A tsunami is a natural cataclysm, which results from a very destructive and powerful sea wave, which are caused by natural disasters, like earthquakes and volcanic eruptions

A Tsnuami is a big wave that is caused by under water movement such as underwater earthquakes are volcano eruptions.