What is the Meaning & Definition of earthquake

An earthquake is an accommodation of the Earth which is perceived with shakes and tremors. Its origin is mainly due to the clash of tectonic plates, although they can also be caused by other phenomena such as the disruption of underground caves, landslides on the slopes of the mountains, etc.

The outermost layer of the Earth called the lithosphere is made up of plates that move across a fluid substratum that is called "mantle"; such displacement is almost imperceptible, only a few centimetres per year. Plates tend to rub against the ones against the others, creating mountain ranges, volcanoes, ocean trenches and so-called "systems failures". It is important to point out that this phenomenon is causing that, nowadays the continents are separated, since in the past they were integrated into a huge block called Pangea. Observed at the present time, the edges of each continent would fit with the other, in the form of a "puzzle".
A phenomenon similar but less intensity and magnitude are called "earthquakes", even though they produce offset plates, failing to reach the density of what would be an earthquake. In addition, these can cause, when they occur in areas under water, known with the name of tsunami.
When the Earth removes itself seeking a balance and a reset due to the movement of plates, it is when an earthquake occurs. At that time, energy is released and the movement spread through waves similar to the sound, both towards the interior of the Earth and outward, causing the destruction of the living area, with the dangers that that implies in this case.
To refer to this phenomenon, scholars used two terms which are intended to be explanatory: hypocenter and epicenter. In the first case, reference is made to the place where there is a break in the Earth's crust and begins the seismic movement. There is precisely where energy release occurs. In the second case, refers to the place of the Earth's surface where the focus power is projected.
In addition, as the majority of natural phenomena, earthquakes have several measuring scales to precisely determine its intensity. The best known is the famous Richter scale with a maximum of 10 points, which would be the largest possible magnitude to a phenomenon of this kind, and clear, which will have the most serious consequences.
Separately, are currently known so-called "induced earthquakes", resulting for example in areas of exploitation and extraction of hydrocarbons (oil, for example). Clear that companies extracting these natural resources, they care too much about the exploitation of raw materials, but little to anticipate natural disasters and prevent deaths or injuries in nearby populations to these places of extraction.
Currently, it is fairly easy to determine which areas are the most likely to suffer alterations of this type, so in theory it would be possible to take precautionary measures. Unfortunately, many of the more exposed areas coincide with poor regions, so these preventive measures cannot be applied.
The biggest earthquakes during the 20th and 21st century have occurred in Indonesia, Japan, Chile, United States, Mexico, Russia and Portugal.
Article contributed by the team of collaborators.