Wednesday, March 16, 2011

Earthquakes causes and effects

Here, i have tried to explain the nature, distribution, causes and effects of this terrifying natural event.A large number of earthquakes are felt all over the globe every year.Most human lives in earthquakes are lost due to collapse of houses. Styles of making houses depend on local climate, construction material available and on local traditions. The small ones are unnoticed while the large ones are felt over thousands of kilometers.When the earthquake struck, the longer, more flexible columns at the front of the building passed the earthquake forces on to the short, stiffer columns in the back instead of distributing the forces equally among all of the columns.Many properly executed buildings are not safe against earthquakes, simply because their foundations were made without considering the earthquake hazard.When an earthquake occurs in a populated area, it may cause deaths and injuries and extensive property damage.
Different types of seismic waves  produce the violent ground shaking, or motion, associated with earthquakes.These wave vibrations produce several different effects on the natural environment that also can cause tremendous damage to the built environment (buildings, transportation lines and structures, communications lines, and utilities).Ground shaking from earthquakes can collapse buildings and bridges; disrupt gas, electric, and telephone service; and sometimes trigger landslides, avalanches, flash floods, fires, and huge, destructive, seismic sea waves called tsunamis.
Tsunami (“Soo na me”) is Japanese for tidal wave. A tsunami is caused by an earthquake, landslide, or volcanic eruption on the sea floor. Tsunamis are often no taller than normal wind waves, but they are much more dangerous.Tsunamis run quickly over the land as a wall of water.

No comments:

Post a Comment