when+the+earth+trembles


 * When the Earth Trembles**

It is called earthquake to any movement of the earth produced by the accommodation of the rocks of the lithosphere. When a shaken with great intensity the surface is called when the earthquake and its intensity is slight tremor is called.
 * The earthquakes:**

**As they occur?** Earthquakes are sudden movements of the earth's crust that occur when two plates are broken and fought as a source of energy that the earth trembles. Sometimes earthquakes may produce large variations in topography as cracks or avalanches but also changes in the course of water, such as in cases of tsunamis.

**SCALES:**

It was developed by seismologists Charles F. Ritcher in 1935 measured the magnitude of the earthquake that releases energy and has 10 stops every ten times higher than the other, that is grade 2 or quake is 10 times greater than a grade 1, and one of grade 3 is 10 times stronger than a grade 2 and so on.
 * Of Ritcher**

It measures the effects of an earthquake as from its epicenter. Its scale runs from 1 to 12 degrees of intensity. The difference from one side of the other depends on the damage caused during the earthquake. The first stop was developed in 1902 by Giuseppe Mercalli. In the world there are several seismic zones that are well identified and demarcated. These are: the circle circumpafico, east of the Pacific Ocean south of the Antilles area transatiaca or rifts or cracks half - ocean Each year there are more than one million earthquakes, but many feel neither. **70%** of them had magnitudes of between **6 and 6.4** degrees on the Ritcher scale.
 * Modified Mercalli**
 * Seismic zones:**

** The seismograph ** :

Recorded seismic waves locates the site of the epicenter and measure its intensity in the Ritcher scale. The first one calling sismoscopio, was invented in the year 132 of our era. ** Danger at sea: ** Tsunamis, or tidal waves are big waves formed by an earthquake or volcanic eruption. They can get to measure 30 meters tall and wipe out coastal cities.

** Vocabulary:

**  ** Seismic waves from the **** epicenter **. - They are expanding concentric circles forming on the surface until the energy disappears


 * Levels of destruction**.- Is the epicenter  greater degree of destruction occurs wave

** Epicenter. **  - Point and that this over the surface to the outbreak.


 * Choque.**-waves are scattered in circles away from the focus and determine the area affected by earthquake

**Levels of earthquakes.-**
 * Focus.** - It is the place where the earthquake originated.

Level 1 = do not feel Level 2 = is felt by people at rest Level 3 = a slight movement Level 4 = trees are shaken Level 5 = one that manages to shed liquids moviminto Level 6 = windows are broken Level 7 = we can not keep up Level 8 = branches of the trees are broken Level 9 = buildings are crumbling Level 10 = land is part Level 11 = soil varies its original form Level 12 = total destruction

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Paulo Alarco