Unseen Comprehension-71 Alim ( Tsunami )

Tsunami.

সুনামী।

The term tsunami comes from the Japanese language meaning harbour  and wave. The term was created by fisherman who returned to port to find the area surrounding the harbour devastated, although they had not been aware of any wave in the open water. 

A tsunami can be generated by any disturbance that rapidly displaces a large mass of water, such as an earthquake, volcanic eruption, landslide or meteorite impact. However, the most commons cause is an undersea earthquake. 

The Indian Ocean earthquake of December 26, 2004, known by the scientific community as the Sumatra-Andaman earthquake, had the magnitude of  9.15. The earthquake generated a tsunami that was among the deadlist disaster in modern history, killing well over 300,000 people.

The tsunami devastated the shores of Indonesia, Srilonka, South India, Thailand and other countries with waves up to 30 m (100 feet). It caused serious damage and deaths as far as the east coast of Africa, 8,000 km away from  epicentre. 

Although often referred to as "fidal waves", a tsunami does not look like a normal wave of much bigger size. Instead is looks rather like an endlessly onrushing tide which forces its way around and through any obstacle. The wave travels across the ocean at speeds from 500 to 1,000 km/h. As the wave approaches land, the sea shallows and the wave no longer travels as quickly, so it begins to 'pile-up' the wave-front become steeper and taller. Most of the damage is caused by the huge mass of water behind the initial wave front, as the height of the sea keeps rising fast and floods powerfully into the coastal area. The sheer weight of water is enough to pulveries objects in its path, often reducing buildings to their foundations. Large objects such as ships and boulders can be carried several miles inland before the tsunami subsides.