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صفحة: 14
Read the encyclopedia entries and find out what makes hurricanes , tornadoes and earthquakes so dangerous . r 7 U / TJC 3 / 76 S are big storms over the ocean . They are caused when the warm water in the ocean meets warm air . The air , water and heat make a spinning system of clouds , rain and wind . When a hurricane strikes land , the rain , strong waves and wind can cause damage to homes , buildings and trees . Hurricanes are measured on the Saffir-Simpson Scale . This scale measures hurricanes by wind speed . Hurricanes are divided into five categories . A Category 1 hurricane has wind speeds of 74-95 miles per hour . A Category 5 hurricane has winds ofat least 155 milesper hour . Meteorologists follow a hurricane ' s progress on satellite pictures . In this way , people are warned when a hurricane is coming . Meteorologists name hurricanes so that they can keep track of them . The names are given in alphabetical order . Both men ' s and women ' s names are used for hurricanes . In some parts of the world , hurricanes are called cyclones and typhoons . The hurricane season is from May to November . TOTDdiJOBS are storms of strong wind over land . They are caused when cold air from the clouds meets warm air rising from the ground . Tornadoes look like spinning , funnel-shaped clouds and they act like giant vacuum cleaners . When they pass over land , they can lift up homes , cars and animals . Tornadoes cannot be forecasted far in advance . When a tornado starts , people have very little time to prepare . Tornadoes are measured on the Fujita Pearson Scale . This scale measures tornadoes by wind speed . An F-0 tornado has wind speeds of 40-72 miles per hour . This type of tornado can cause damage to trees . An F-5 tornado has wind speeds of 300 miles per hour and is so powerful that it can lift homes and cars from the ground . Tornadoes are also called twisters . E 3 rtrKjU 3 kB 5 are sudden shakes on the earth ' s surface . They are caused by shifts in pieces of the earth's crust along fault lines . Earthquakes usually only last for a few minutes , but they can cause a lot of damage . Bridges and buildings are destroyed during strong earthquakes . Sometimes people are caught under the rubble of buildings and need to be rescued . Although scientists are learning a lot about earthquakes , they are still unable to predict where and when earthquakes will happen . Earthquakes are measured on the Richter Scale . This scale measures earthquakes by the strength ofthe earth's movement . Earthquakes below 2 on the Richter Scale are usually not felt by people . An earthquake that measures 5 on the scale causes a lot of damage . An earthquake 0 f 6 or 7 causes deaths and major destruction . In 1 999 , there was an earthquake in Turkey that measured 7 . 4 on the Richter Scale . Over 16 , 000 people were killed , and thousands of people were left homeless . Earthquakes are also called quakes , shakers and seismic activity .
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