Earthquake Defined

Earthquake Defined

What is Earthquake ?

An earthquake is the sudden movement of the Earth , due to the sudden release of stored energy for a longer time. The crust of the earth is consisted of a dozen plates of about 70 km thick, each with different physical and chemical characteristics. These plates ("tectonic") are settling into a process that takes millions of years and have been given the shape we know today to the surface of our planet, causing the continents and geographic reliefs in a process. Mostly these movements are slow, but in few conditions these plates collide like giant icebergs ground on an ocean of magma present in the depths of our Earth, avoiding its movement. That make a plate to move over or under the other causing slow changes in topography. But if the movement is hampered begins to build an energy of stress at some time be released and one of the plates will move sharply against another breaking and then releasing a variable amount of energy that causes the earthquake.

The areas in which the plates exert this force between them are called faults and are, of course, the points most likely originate seismic. Only 10% of the earthquakes occur away from the boundaries of these plates.

Underground process accured by a volcano eruption process may cause a similar phenomenon.

In general the term earthquake is associated with earthquakes of considerable size, although rigorously its etymology means "Earth movement".

Hypocenter
It is the point where the depth of the Earth from where the energy is released in an earthquake. When it occurs in the bark of it (up to 70 km deep) is called superficial. If it occurs between 70 and 300 km is called intermediate and if greater depth: deep (remember that the center dela Earth is approximately 6,370 km deep).

Epicenter
Is the point of the surface of the Earth directly above the hypocenter course where earthquake intensity is greater.