A terrifying example of the sea’s power saw about 200,000 people die in 12 different countries at the end of 2004. The devastation (毁坏) was caused when a massive earthquake sent tsunamis smashing into India Ocean coastlines.
Communities in Sri Lanka, Indonesia, Thailand, India, Malaysia and East Africa have been destroyed by the monster waves. Whole towns were simply swept aside by the power of the water. Cars, trains and buildings could not survive, let alone the people who stood in the way.
The earthquake measured 9.0 on the Richter scale (里氏地震) and occurred off the coast of Indonesia. It was recorded as the fifth strongest since 1900. Scientists said the quake was as powerful as a million of the atomic bombs that were dropped on Japan during World War Ⅱ. "This may be the worst natural disaster in recent history, because it is affecting so many heavily populated coastal areas," said Jan Johnson, a U.N. official.
Because such waves rarely happen in the India Ocean, there is no system in place to warn coastal communities they are about to be hit.
Tsunami is Japanese for "harbor wave". They are usually caused by a sudden rise or fall of part oF the earth’ s crust (地壳) under the ocean. Tsunamis often happen in-oceans and they are most common in the Pacific. Normally a tsunami includes a series of waves.
Tsunamis can be very long—as long as 1,000 kilometers--and be as far as one hour apart. They are able to cross the entire ocean without losing much energy. One of the most striking facts about Tsunamis is that an earthquake on one side of the Pacific Ocean cause giant waves and destruction on the other side.
When the ocean is deep, tsunamis can travel unnoticed at a speed of up to 800 kilometers per hour. They can cross the entire ocean in a day or less.
The wave may only be a few meters high in the ocean but when it is near the shore and reaches shallow water, the wave builds up very quickly in height. Witnesses (目击者) in some areas of Indonesia reported seeing up to 10-meter-high waves crash into the shore.
When the ocean is deep, the tsunami becomes more terrifying because ______.