but in shallow water, like when it approaches the beach, or the seabed shallows it grows in height surging towards the shore with terrific force. They are usually no higher than normal waves but then they aren't considered as a tsunami. Tsunami aren't very big to cause that much destruction. They are only about as high as a four storey building but they cause devestation. They have a lot of energy. They last for about a minute. and on and have terrific energy. The average height of a large tsunami is 35 feet.
How do earthquakes cause tsunami?
What happens is it changes the shape of the sea floor at the EPICENTER. If the sea floor moves down, the sea drains away rapidly first before the waves come; a good warning of tsunami. If the sea floor moves up then the sea level rises rapidly before the tsunamis; also a good warning of tsunami.
How do landslides falling directly into deep water or under the sea cause tsunami?
because it has such volume, it would disturb the water and cause a tsunami.
How do volcanic eruptions cause tsunami?
Under the sea if a volcano erupts it is very easy to understand. A volcano erupts with terrific energy. Under the sea, of course it would cause a tsunami.
At a beach with deep water if a volcano erupts lava, the sea floor would collapse rapidly because there is no lava to hold it up. That would cause a tsunami. The sea would drain away first and then the tsunamis would come.
Very rarely, a meteorite or other cosmic body lands into the sea, and causes a tsunami a high as a mountain! you would be dead before you noticed anything. It would be a just a split second and it would be all over. The waves reach the center of continents.
ABOVE: a John and Jackie picture.
