Seafarers have always respected the power of wind and water. This is especially the case during storms at sea, where ships run the risk of damage or sinking from strong winds and high seas. Large and powerful storms, referred to as “closed cyclonic circulations,” are especially dangerous and have caused massive destruction throughout all of recorded history.
Tsunami waves, which hit India for the first time on Sunday wreaking havoc across the southern coastline, are a known phenomenon in the Pacific Ocean region, which stretches from Chile in Latin America to Japan in East Asia.
The waves are usually triggered by seismic disturbances — coastal earthquakes, volcanic eruptions or undersea landslides — that jolt the ocean floor.
Tremors under the sea displace ground surface, sending the water radially outward in concentric circles from its epicenter. The result is a deep wave, stretching from the sea’s surface to the floor that travels horizontally at speeds of up to 500 miles per hour and reaches heights of 50 to 100 feet.
The tsunamis that hit India on Sunday were caused by a massive earthquake on the Indian Ocean near Sumatra in Indonesia. Similar waves have hit six other countries, claiming thousand of lives.
The waves travel faster in deep water, rising further as they approach shore. In open sea, Tsunamis are only about a metre high, but when they reach a shoreline, they can be taller than a house and weigh millions of tonnes.
Though the bottom of the wave is slowed down by the sharp elevation of the ocean floor near the coast, its top part keeps moving at the original speed. As a result, vast quantity of water piles up and finally crashes over the shore with amazing force, thus causing massive destruction
The first sign of an approaching Tsunami is the sea tide receding from the shore, which leaves a large part of the sea floor exposed. The ocean water then flows towards the shore faster than before, resulting in high waves. This phenomenon is repeated several times before the Tsunami itself hits the land.
The Tsunamis can travel long distance without losing the original power. Neither islands nor reefs diminish their speed or power.
Usually the waves do not dissipate until they strike a continental landmass, and some waves even travel back and forth across the ocean for over a week.
Japan is one of the two Asian countries — the other being Indonesia – to be frequently hit by Tsunami waves. In fact, the word tsunami is derived from the Japanese language and is used by Japanese to describe very long, low seismic sea waves.
Tsunamis are common in the Pacific Ocean, as there is significant movement of the earth’s tectonic plates in the region.
The devastating earthquake and tsunamis that hit Asian countries will deal a fresh blow to the tourism industry there but aren’t expected to produce crippling economic problems in the region, economists say.
|– By Jobships.com|