Earthquakes are caused by the sudden release of energy along faults plane. The strain that builds up in the rock will ruptures when the elastic limit of the rock is exceeded thus released the elastic energy as seismic waves. The greater released energy, the greater strain that stored in the rock. A sort of the energy that released by and earthquake will travels through the earth`s crust which caused damages to life and structures. The earthquakes can be even smaller and even larger (W.Spence, S.A.Sipkin, & George L. C, 1989).
Earthquakes are three dimensional events which the waves will move outwards, horizontal and vertical plains. This condition produces three different types of waves which can be defined through its distinct behavior and some of this wave only travel through certain stratums within the earth.
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