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Disaster Management - Earth Quakes

 Earth Quakes :

An earth quake is a sudden vibration caused on the earth's surface due to the sudden release of tremendous amount of energy stored in the rocks under the earth's crust.


How earth quakes occurs ?

The earth's crust has several tectonic plates of solid rock. These plates move slowly along their boundaries. When friction prevents these plates from slipping, stress develops and results in sudden fractures along the fault lines within the plates. This causes earthquakes and the violent vibrations in the earth.



Causes of earth quake :

1.Earth Quakes are caused  due to the equilibrium in any part of the earth crust. This disequilibrium is caused by volcanic eruption, hydrostatic pressure of man-made water bodies like reservoirs, dams, and lakes, which inturn causes movements of plates.

2.Underground nuclear testing.

3.Decrease of underground water level. 



Effects of earth quake :

1. The shocks produced by earthquakes in hilly and mountainous area may cause land slides, which damage the settlements and transport systems.

2. It also collapses houses and other structures due to poor construction and the people die in thousands depending on the severity of  the quake.

3. Severe earthquake results in deformation of ground surface.

4. Tsunami, The seismic waves caused by earthquakes trough sea water and generates high sea waves called tsunami. This causes great loss of life and property.

Earth Quake Management :

1. Damage to property and life can be prevented by constructing earthquake - resistant buildings in the earthquake prone areas.

2. Wooden houses are preferred in earthquake prone areas as in Japan.

3. Seismic hazard map should give the information about the magnitude of intensity of anticipated earthquakes and seismologist should analyze the pattern of micro seismicity and indicate the possibility of occurrence of earthquakes in a potential area.



 

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