NATURAL DISASTER--- EARTHQUAKEThere are many natural disasters in the world. Earthquakes are one of the most dangerous, over a million earthquakes occurs each year. Although some are too small to be noticed, others may cause damages, death and destruction.Earthquakes are caused by the movement of the Earth's crust. The crust is made up of plates floating on mantle. When two plates push against each other, it causes earthquakes which may destroys towns or form new climates.If an earthquake happens under the sea and causes huge waves, it is called a "tsunami". A tsunami can sweep across oceans at the speed of 800 kilometers per hour. When an earthquake happens out in the open seas, the wave can only be about 1 meter high, but when it meets land, it may grow up to 30 meters high and can lead to enormous damage. For instance, a harbor on Okushiri Island, Japan, was destroyed by a tsunami in 1993. When an earthquake happens on land, it may cause more damage to buildings, harm, and death to humans. Described below is how an earthquake usually happens: 1. Barely felt but hanging objects may swing. 2. Felt by all and windows shatter and buildings collapse. 3. Serious damage, cracks open in the ground. 4. May cause death, and landscape changes. The San Andreas Fault in California is one of the biggest fault lines in the world. Fault lines are along the edge of a moving plate. Most earthquakes happen at fault lines. This is how and what an earthquake does. At first, the focus (centre) of an earthquake sends out shock waves along fault lines through layers of rocks. On land, it causes damage to buildings. An earthquake which struck Turkey was quite large, many people died and many bui...
