Unit 6 Disaster and hopeElephants on the coast of Thailand are acting strangely. They stamp their feet and signal toward the hills. The sea draws back from the beaches. Fish fall heavily in the mud. Suddenly, a huge wave appears.This is no ordinary wave. It is a tsunami!Tsunami waves are larger and faster than normal surface waves.A tsunami wave can travel as fast as a jet plane and can be as tall as a tenstory building. Imagine dropping a stone into a pond. The water on the surface ripples. A tsunami is like a very powerful ripple. Tsunamis begin when the ocean rises or falls very suddenly. Large amounts of seawater are displaced. This movement causes huge waves.If a tsunami happens, there must be some kind of force that causes the ocean water to become displaced. Most tsunamis are caused by underwater earthquakes. However, volcanoes, landslides, large icebergs, and even meteorites are able to cause one of these giant waves.Tsunamis are extremely powerful. Ordinary waves lose power when they break. Tsunami waves can remain powerful for several days. They can kill people, damage property, and completely ruin an ecosystem in just one hour.Scientists have no way of predicting when a tsunami will hit. However, if a powerful enough earthquake happens ， scientists can send out a warning or a watch. When people are informed of a watch or a warning, it is best not to get caught unaware when a tsunami is on the way!开启快乐学习之旅泰国海岸的大象的行为很奇怪。他们跺着脚，示意向山上走去。海水从海滩上退去。鱼重重地掉进泥里。突然，一个巨大的波浪出现了。这不是普通的波浪。这是海啸！[知识点击]1．tsunami n. 海啸 2．ripple v. 起涟漪3．landslide n. 塌方 4．meteorite n. 陨石5．on the way 即将来临模块核心素养导航第一课时 Startin...
