There are three stages of a tsunami
Generation - generation of a tsunami is caused by any force that disturbs a water column(earthquake, landslide, volcanic eruption)
Generation - generation of a tsunami is caused by any force that disturbs a water column(earthquake, landslide, volcanic eruption)
Propagation - propagation of the displaces water occurs as it moves across the ocean. When a tsunami is generated, the waves will spread out in all directions. A tsunami can travel as fast as 950 kilometers per hour through deep water and have extremely long wavelengths in the deep ocean.
Inundation - Inundation is the stage which can result in flooding in localised areas. Less frequently, a tsunami can result in more serious inundation of coastal land, serious threats to lives and damage to property, especially in low lying coastal areas.
Although all tsunamis are the same, some may look and behave differently based on the shape of the sea floor and coastline. As a tsunami moves into shallow water their amplitude may increase; this is called shoaling, shoaling does not occur in every coastal environment. It is more likely to occur in a bay, harbour or lagoon where the wave is funnelled as it moves inland.
Although all tsunamis are the same, some may look and behave differently based on the shape of the sea floor and coastline. As a tsunami moves into shallow water their amplitude may increase; this is called shoaling, shoaling does not occur in every coastal environment. It is more likely to occur in a bay, harbour or lagoon where the wave is funnelled as it moves inland.
What happens when a Tsunami its the shore?
Drawdown - If the wave trough(lowest point) arrives before the wave crest(highest point) there may be a drawdown of the coastline which exposes the ocean floor
Inundation - As a tsunami approaches the coastline, the speed reduces and wave height can grow significantly - up to several meters. It is not so much the movement of the water that makes a tsunami dangerous but the energy moving through; this is when the potential inundation of normally dry land occurs.
Dangerous rips and currents - A relatively small tsunami may result in strong rips and currents which stops swimmers or surfers to go into the ocean.