Earthquake is a natural phenomenon

Earthquake is a natural phenomenon is a fast followed by a ground vibration Bartdadat called seismic waves, and this is due to break up the rock and shifteddue to the accumulation of internal stresses as a result of geological effectscaused by the movement of earth plates. May arise as a result of earthquake orvolcanic activities as a result of the presence of landslides in the layers of the earth. Cause earthquakes to rupture of the land and depletion of the springs or the appearance of springs of new or the occurrence of ups and downs in the earth's crust and also cause high waves under the sea (the tsunami) as well as theirsubversion of the buildings, transportation, facilities and often result inmovements of convection in Almtkor Maori (Asthenosphere) that drive platecontinental, causing tremors are occurring earthquakes. The earthquakes may occur in ruins Kberao determine the degree of earthquake index and measured by from 1 to 10: 1 to 4 earthquakes may not occur any damage which maysense it only, from 4 to 6 moderate earthquakes damage may cause damage to homes and stays, while the maximum score any of the 7 to 10 Visttia earthquakedestroyed the city completely and dug under the ground to disappear withdamage to the neighboring cities How do earthquakes consist

During the process of vibration affecting the earth's crust generated six types ofwaves, shocks, of which two relate to the body of the earth where the affect onthe inner part of the land, while the four waves of the other are surface waves, and can distinguish between these waves also through the kinds of movements that affect the particles rocks, where to send the initial waves or pressurewaves, particles oscillate back and forth in the same direction of the waves,while the movement of the secondary waves or transverse vibrationsperpendicular to the direction they went. Usually the initial waves move faster than secondary waves, and then, when an earthquake occurs, the first wavesarrive and are recorded at geophysical research stations all over the world are the primary and secondary waves.