earth quake ppt final......................

An earthquake – also called a quake, tremor, or temblor – is the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves.

1. EARTHQUAKE

2. CONTENTS Earthquake definition Causes of earthquake Effects of earthquake Seismic zone Richter scale Seismograph Protection against earthquake Destruction caused by earthquake Reference ‹#›

3. ‹#› Earthquake is the sudden shaking or trembling of the earth which lasts for a very short period of time. What do you mean by earthquake?

4. CAUSES OF EARTHQUAKE ‹#› Earthquake is caused by a disturbance deep inside the earth’s crust. The outermost layer of the earth is called crust is not one piece . It is fragmented into many plates. These plates are moving continuously (tectonic plates). So when one plate moves under the other plate they brush against each other. Due to this collision on the earth’s crust a disturbance is produced. This disturbance is seen as earthquake on the surface of the earth.

5. ‹#› Earthquake can cause floods, tsunamies, landslides and damage to life and property. EFFECTS OF EARTHQUAKE

6. Seismic zone or fault zone ‹#› The boundaries of the plates are the weak zones where earthquake are more likely to occur. They are called seismic zone or fault zone.

7. How do we measure earthquake ? The power of an earthquake is expressed in terms of a magnitude on a scale called the Richter scale . If the value in Richter scale is 7 then we call such earthquake as destructive earthquake . It can cause a huge damage. ‹#›

8. SEISMOGRAPH ‹#› Seismograph  is an instrument which measures and records the magnitude of an earthquake in terms of the shock waves it produces. They contain a weight and a pen attached to a spring (below). The  seismograph  is bolted to the ground so during an earthquake it moves with the ground, while the weight and pen remain still. The pen moves across a rotating paper roll recording the seismic waves.

9. ‹#› Protection from earthquake

10. ‹#› DESTRUCTION CAUSED BY EARTHQUAKE

11. REFERENCE TEXT BOOK ‹#›

12. ‹#› THANK YOU