EARTHQUAKE

   EARTHQUAKE

Earthquake is a sudden vibration of the earth's surface caused by sadden blow inside the earth.

EFFECTS OF EARTHQUAKE

1. Earth's surface is sudden vibrate, rumbling and roaring noise come from underneath.
2. Roads are fissure d, railway line are twisted and bridges are destroyed.

landslides may occur in hilly regions.

CLASSIFICATION 

1. Earthquake due surface cause.
2. Earthquake due to volcanic cause.

Earthquake due to tectonic cause.

ORIGIN

The tectonic earthquake are the most common, and therefore the most important. the forces that cause tectonic earthquakes are the same which cause faulting and produce mountains on earth's surface.

EARTHQUAKE WAVES

During an earthquake 3 types of waves are generated which is called 

1. P-waves or primary waves
2. S-waves or secondary waves
3. L-waves or long waves 

EARTHQUAKE SCALE

Magnitude	Earthquake Effects	Estimated Number Each Year
2.5 or less	Usually not felt, but can be recorded by seismograph.	900,000
2.5 to 5.4	Often felt, but only causes minor damage.	30,000
5.5 to 6.0	Slight damage to buildings and other structures.	500
6.1 to 6.9	May cause a lot of damage in very populated areas.	100