Gloria Machado León 11 abril, 2018
They have inspired controversial Hollywood films in which it is never possible to define between reality and fiction. They have devastated cities raised on the margins of the sea and swelled the list of little credible stories of the occasional sailor. Beyond legend and speculation, there are waves of gigantic proportions, capable of eliminating everything that stands in their way. How much do we know about tsunamis or tsunamis? The term tsunami comes from the Japanese language and means “wave in port”, while tsunami is the corresponding word in Spanish. The first reports date from the year 479 a.n.e., date from which it is estimated that more than 350 have occurred throughout the world. The text Let’s know the sea defines it as the “phenomenon in which large-scale marine waves arise from the action of earthquakes or volcanic eruptions on the ocean floor.” The detachment of large masses of land or ice or the shift of the seabed also appear as possible causes. It also states that tidal waves can travel across the surface of the ocean up to five thousand nautical miles and reach speeds in excess of 500 miles per hour. Another recently published book, Coastal Zones of Cuba, establishes a curious parallelism: he comments that these waves travel with a speed similar to that of a jet propulsion plane and that, when arriving at the land line, its speed decreases to that of a high performance runner in the hundred meters flat. Also highlights that it is a series of waves that can act for hours and that is not the first, necessarily, the largest and most powerful. Between one and the other there can be a time of five to 60 minutes. An identity feature of the tsunamis is the sudden withdrawal of the sea, a very different from what occurs before the phenomenon of low tide, which, by the way, does not bear any relationship. As the wave approaches the coast, its amplitude decreases and the height increases, giving rise to the formation of a wall of turbulent waters that rises tens of meters above the surface and that leaves a devastating mark on the ecology. and human resources. Although tsunamis occur mostly in the Pacific Ocean area, throughout history they have also been reported in the Caribbean Sea, with lower dimensions, clearly. For example, in 1755 a great earthquake took place in Lisbon, whose repercussion resulted in a small tsunami in the Lesser Antilles. In Cuba, they have also been reported, mainly, in the north-eastern areas. During the year 1946, one occurred due to an earthquake in the Dominican Republic and another in 2009 due to the earthquake in Haiti, which occurred without significant damage. The scholars affirm that of our coastlines the most vulnerable are those of the south of the archipelago and those of the east. But we should not take refuge in panic, after all, in our region do not occur tsunamis like those of Japan or Hawaii and much less, like the apocalyptic waves that, every time, appear in the controversial Hollywood filmography.