A More Revealing Facts of the Earth

Earthquake occurs when sudden movements take place within and below the Earth's crust. They cause fractures and faults in the crust and the sudden release of built-up stress send shock waves. Tectonic plates then move in sudden jerks.

Shock waves range from slight vibrations which are hardly felt to very strong vibrations which can cause great destruction.

Magnitude of an earthquake can be measured with an instrument called a seismometer, ranges from 0 to 9 on the Richter scale.

Source of the earthquake --> focus

Epicenter --> point on the Earth's surface  directly above the focus.  It receives the strongest shock waves and therefore, maximum destruction of lives and property.

FACTORS INFLUENCING EXTENT OF DAMAGE

1. Magnitude of earthquake    :     An earthquake which measures 2 and below on the Richter scale is barely noticeable while 7 and above show major earthquakes.

2. Depth of Focus :Those with shallow focus (depth of 0 - 70 km) is most devastating earthquakes .

3. Epicentre     :    Places near the epicentre are more badly damaged than those further away from it.

LOCATIONS

Earthquakes usually occur along plate boundaries, just like volcanic eruptions. Some of the major earthquake zones are :

1. The Pacific Ring of Fire

2. The East- African Region

3. The Himalaya-Asia Minor Region

This WebPages is done for the competition of ThinkQuest