What is Tsunami?

What is a Tsunami?

The term "tsunami" describes a series of long oceanic waves that is created in after a large volume of water has been displaced. “Tsunami” is derived from the Japanese language, and when transcribed to English, it means “Harbor (“tsu”) Wave (“nami”). The term was first coined by Japanese fisherman to describe the destruction caused by largewaves that would wipe out entire areas surrounding the harbor. The strange thing was that they would experience little to no effects of thetsunami on their boats in their sea.

Tsunamis are waves characterized by moving at fast speeds, sometimes having a high amplitude (wave height), and long wavelength – thus tsunamis are essentially giantwaves . In the deep ocean, tsunamis are barely felt since they are masked by the sheer vastness of the rest of the ocean. This is the reason why those aforementioned Japanese fishermen were not affected. However, tsunamis can be absolutely devastating as ocean’s depth decreases with approaching land.

The speed at which a tsunami travels is another impressive characteristic. Tsunamis can travel at great speeds across an ocean, usually from 500 to 1000 kilometers per hour, with hardly any energy losses and are barely noticeable out at sea. This is the reason whytsunami’s generated from one region can affect other regions thousands of kilometers away. With the recent tsunami is South Asia, the epicenter of the tsunami was just of the coast of Indonesia, and yet the tsunami struck with the same amount of force in Eastern Africa – some 14 hours after Southeast Asia was hit.

Huge EarthQuake

A huge earthquake has struck the Indonesian island of Sumatra, triggering blackouts, widespread panic and tsunami warnings.

The 7.8 magnitude quake, the second major temblor to hit the island in six months struck at 5.15 am local time (2215 GMT) 125 miles off the city of Sibolga, on Sumatra's north west coast, which was devastated in the 2004 Indian Ocean tsunami.

Buildings shook and residents of coastal cities fled to higher ground, and there were blackouts in Medan and Banda Acheh. However there were no reports of major damage or casualties and the tsunami warnings issed by the Indonesian Government and Thailand were lifted two hours later.

Residents of Banda Aceh, the provincial capital, said they felt the earth shudder with frightening intensity for about a minute as the first earthquake was followed by three strong after-shocks.

Many fled their homes or piled onto motorcycles to head inland in fear of destructive waves .

"People panicked and ran out of the house, it lasted almost a minute," an AFP reporter in Banda Aceh said. "I saw a lot of people who live close to the sea using motorcycles to drive inland."

The US Geological Survey said the earthquake struck at a depth of 29 miles (46 km). The epicentre was 60 kilometres southeast of Sinabang, on Simeulue Island, the epicentre of the 2004 earthquake.

Officials in Sinabang and the Indonesian capital of Jakarta said there were no immediate reports of damage near the epicentre. "Our personnel haven't found any damage in Sinabang," local police chief Dedi Junaidi told MetroTV.

Indonesia sits on the so-called Pacific rim of fire, along which 90 per cent of the world's earthquakes and 80 per cent of the world's largest earthquakes occur.

Today’s earthquake comes six months after a 7.6 magnitude quake devastated the Sumatran city of Padang, 200 miles (350 km) to the south of Sibolga, killing 1000 people.

Global Warming

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