The swell is the maritime movement induced by the wind that makes contact with it directly, this generates waves with a measure of 1.5 to 2.5 meters high. These water movements due to the friction of the wind on the sea surface have a constant rhythm of approximately 20 seconds, the influence of the wind can propagate up to 200 meters towards the bottom of the sea, as the propagation of the wind force is in the form The wavelength of the wave diminishes the further it is from the main air stream.
Many people tend to confuse tsunami with storm surge, both are different terms since a tsunami as such presents an opposite conjugation to the storm surge, in the development of this maritime phenomenon the sudden movement of the water mass comes from the depth that being a Current so strong that it continues to move to the surface, generating waves of immense sizes exceeding 5 or 6 meters.
The name of the storm surge in scientific terms is "storm surge" and as mentioned it is the push of the wind so that the water reaches higher sea levels; This is not only the product of air movement, for this purpose the existence of a low pressure is combined, which would be a lower thrust to generate the swell, it is important to note that this occurs only in shallow waters which is another difference as opposed to the tsunami.
When there is a conjugation between the swell and the high tide, large and unpredictable waves are obtained, this is due to the fact that the water is managed between the wind and the tide; Dangerous swells are not observed frequently, they occur when there are tropical phenomena as well as when not very powerful storms develop. Some examples of major swells are: Mahina in 1899 which produced an increase of up to 13 in the Australian sea level, Hurricane Katrina in 2005 which wiped out the population of St. Louis in Mississippi (United States) and in 1970 Bohla was the tidal wave that claimed many lives in Bengal.
