earthquake and natural disasters

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earthquake and natural disasters

  1. 1. Earthqua ke
  2. 2. What is an earthquake?  Earthquake are the shaking rolling or sudden shock of the earth surface..  They are the Earth natural means of releasing stress..Webpage
  3. 3. What causes an earthquake?  There are about 20 plates along the surface of the earth that move continuously and slowly past each other.When the plates squeeze or stretch huge rocks form at their edges and the rocks shift with great force ,causing an earthquake..
  4. 4. What is a fault?  A fault is an area of stress in the earth where broken rocks slide past each other causing a crack in the Earth surface…  There are four major types of fault which are as follows:dip-slip normal,dip-slip reverse,strike slip,and oblique-slip.
  5. 5. What is a seismograph?  A seimograph is an instrument used for recording the intensity and duration of an earthquake.. What is a tsunami?  A tsunami is a large ocean wave usually caused by an underwater earthquake or volcanic explosion.
  6. 6.  Tsunamis are not tidal waves.  Tidal waves are caused by the forces of the moon,sun and planet upon the tides,as well as the wind as it moves over the water.
  7. 7. How we measure the earthquakes?  Richter scale:Is a seismic scale which measure the magnitude of an earthquake.  Mercalli scale:Is a seismic scale which measure the intensity of an earthquake.  The instrument that is used for measure an earthquake is called seismograph.
  8. 8. Disadvantages of Earthquake:  The destruction of the building and structures such as “houses” collapsed and bridges broken down,cracking dams ,rail deformation and so on.  The destruction of natural objects such as mountains and landslides etc.

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