What is the source of earthquakes? The causes and consequences of earthquakes

Having ascertained, as a result of what processes in the earth's crust there are destructive tremors, modern science, nevertheless, can not save mankind from vain victims.

On a powder keg

Earthquakes at all times were unpredictable and tragic for mankind, and technological progress, the computerization of science and the mathematical models done on paper helped to sort out the processes taking place in the earth's crust, but not enough to prevent them or at least minimize them Their consequences. After all, if it was formerly believed that earthquakes can occur only in certain places on the globe - at the junction of tectonic plates or in zones of increased volcanic activity, in recent years they have been repeatedly recorded where they were least expected.

At different times, they were felt by the inhabitants of Yakutia, Odessa and Moscow, and as a result of tsunamis accompanying the earthquakes, cities and regions that were several tens of thousands of kilometers from the epicenter often suffered.

Origin of the phenomenon

A clear answer to the question of what is the source of earthquakes, to this day does not exist - scientists do not adhere to a single interpretation of this concept. Usually it means a specific section of rocks, located some distance from the surface of the earth, where due to the accumulated stress, various tectonic shifts and deformations occur. They lead to the emergence of seismic waves that spread in all directions, and reaching the surface of the earth, produce destruction on it and cause human casualties.

A common misconception

The outbreak and the epicenter of the earthquake, contrary to the opinion formed by the incompetence of the media, are not synonymous concepts at all. But many people can not figure out what the difference is. If by what is the focus of earthquakes, we mean a certain space in the depths of the earth's crust or the upper layers of the mantle, then the epicenter in the scientific sense is the point that is the projection of the hypocentre on the surface. And it is not necessary that the strongest tremors are felt here.

There are a number of reasons why the most serious damage can occur in territories that are located at a considerable distance from the epicenter. This, for example, is the heterogeneity of the earth's crust, which directly affects both the propagation and the nature of the waves themselves.

Rules and Exceptions

Most of the recorded earthquakes originate within the boundaries of the earth's crust, that is, at a distance of no more than 50-60 kilometers from the surface of the earth. However, the history knows cases when the depth of the source of the earthquake was up to 500 kilometers or more, but the natural disasters themselves were noticeable, and their consequences were catastrophic (in particular, the earthquake in the Sea of Okhotsk in May 2013).

The most destructive, as a rule, are tremors arising at insignificant depth, since they are accompanied not only by seismic, but also by poorly studied surface waves.

The place from which everything begins

Arguing what is the source of earthquakes, experts have in mind a certain volume of rocks, but the process of moving or breaking the earth's crust begins as a result of the release of a huge amount of energy not in several areas simultaneously, but at one particular point taken. This is the center of the earthquake focus - the place where waves are generated, subsequently recorded by seismologists.

How to determine the earthquake?

For this purpose there are instruments-seismographs, with their help waves are captured. Analyzing all the values, experts can say where the earthquake will be, what is the impact force of the tremors. Seismologists warn people about this in order to minimize the consequences of the tragedy and prevent victims, although it is very difficult to determine the scores with great accuracy. It is worth noting that it is not always possible to do this in a timely manner.

People noticed that animals also respond to the approach of an earthquake. For example, chickens, dogs, pigs, rats begin to behave restlessly a few hours before the tremors. Therefore, the villagers are used to watching their behavior.

Guessing on the coffee grounds

If the science has been determined with what is the source of earthquakes, then the application of knowledge about the nature of tremors in practice is much more complicated in practice. History knows many cases when scientists could predict the place and date of another cataclysm, but even in the 21st century, it is not necessary to rely on forecasts based on observations and models.

For example, the monstrous earthquake in Southeast Asia, which claimed the lives of about 250-300 thousand people and was among the three strongest in modern history, has become a complete mystery for seismologists. As well as the emergence of a devastating tsunami as a result of the Japanese earthquake in 2011.