Hi, Im sure everyone who’s got a radio, TV, ear, mouth has heard about the deadliest tsunami in recorded history, so I thought it appropriate to describe what a tsunami actually is...
A tsunami is a natural phenomenon consisting of a series of waves generated when water in a lake or the sea is rapidy displaced on a massive scale. Earthquakes, landslides, volcanic eruptions, and the impact of extraterrestrial bodies such as meteorites, can generate tsunamis which can rapidly and violently inundate coastlines, causing devastating property damage, injuries, and loss of life.
The term ’’tsunami’’ comes from the Japanese language meaning harbour (’’tsu’’) and wave (’’nami’’). The term was created by fishermen 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 is not a sub-surface event in the deep ocean; it simply has a much smaller amplitude (wave heights) offshore, and a very long wavelength (often hundreds of kilometers long), which is why they generally pass unnoticed at sea, forming only a passing ’’hump’’ in the ocean.
Tsunamis were historically referred to as tidal waves because as they approach land they take on the characteristics of a violent onrushing tide, rather than the sort of cresting waves that are formed by wind action upon the ocean (with which people are more familiar). However, as they are not actually related to tides, the term is considered misleading, and its use is deprecated by oceanographers.
The magnitude 9.0; Indian Ocean Earthquake triggered a series of lethal tsunamis on December 26, 2004 that killed more than 160, 000 people, making it the deadliest tsunami in recorded history. The tsunami killed people over an area ranging from the immediate vicinity of the quake in Indonesia, Thailand and the north-western coast of Malaysia to thousands of kilometres away in Bangladesh, India, Sri Lanka, the Maldives, and even as far as Somalia and Kenya in eastern Africa.
Unlike the Pacific Ocean, there is no organised alert service covering the Indian Ocean. This is in part due to the absence of major tsunami events since 1883 (the Krakatoa eruption).
I hope the governments of these areas wake up and do something that would avert such a huge tragedy.