found out, a result of some processes in the crust occur devastating tremors, modern science, however, unable to rid humanity of the victims vain.
on a powder keg
Earthquakes have always been for mankind phenomena unexplored and tragic, and technological progress, the computerization of science and committed to paper the mathematical models though, and helped to understand the processes occurring in the Earth's crust, but not enough to prevent themor at least minimize their effects.After all, if earlier it was believed that the tremors may occur only in certain parts of the world - at the junction of tectonic plates, or in areas of high volcanic activity, in recent years they have repeatedly documented where they had expected the least.
At different times they felt the people of Yakutia, Odessa and Moscow, as a result of the earthquake-related tsunamis often suffer cities and regions that are at a distance of several tens of thousands of kilometers from the epicenter.
Origin phenomenon
clear answer to the question of what the focus of the earthquake, this day does not exist - scientists do not adhere to a single interpretation of the concept.Usually, it means the specific area of rocks, located at some distance from the surface of the earth, where, because of accumulated stress there are various tectonic shifts and deformations.They give rise to seismic waves that spread in all directions, and reaching the earth's surface, producing her fracture and cause casualties.
common misconception
homes and epicenter of the earthquake, contrary to the opinion, formed due to the incompetence of the media - the concept is by no means synonymous.But many people can not figure out what the difference is.If by the fact that the focus of the earthquake is understood some space deep in the Earth's crust and upper mantle, the epicenter in the scientific sense is the point which is a projection of the hypocenter on the surface.And not necessarily that it is felt the strongest tremors.
There are a number of reasons why the most serious damage can be from territories at a significant distance from the epicenter.This, for example, the heterogeneity of the crust, directly affects both the spread and the nature of the waves themselves.
rules and exceptions
Most recorded aftershocks born within the borders of the earth's crust, that is not more than 50-60 kilometers from the surface.However, history has known cases where the depth of the earthquake was 500 kilometers or more, but the natural disasters were thus tangible, and their consequences - catastrophic (in particular, the earthquake in the Sea of Okhotsk in May 2013).
most devastating are usually tremors arising at a small depth because they are accompanied by not only seismic but poorly understood and surface waves.
place from which everything begins
Arguing that such a hotbed of earthquake experts have in mind a certain amount of rocks, but the process of moving or breaking of the crust begins by releasing huge amounts of energy in a few areas at a time, and in one particularly takenpoint.This is the center of the earthquake - a place where the waves are generated, subsequently recorded by seismologists.
How to determine the earthquake?
exist for this equipment, seismographs, with them trapped waves.After analyzing all the values, experts can tell where the earthquake will be, what is the force of impact shocks.Seismologists warn people about this, to bring the tragedy to a minimum and prevent the victims, but to determine the points with high accuracy is very difficult.It is worth noting that to do so in a timely manner is not always possible.
People have noticed that the animals also respond to the approach of an earthquake.For example, chickens, dogs, pigs, rats behave restlessly for a few hours before the aftershocks.Therefore, the villagers used to observe their behavior.
guesswork
If so, what is the focus of the earthquake, science was defined, with the knowledge of the nature of the tremors in practice, the issue is much more complicated situation.History knows many cases when scientists managed to predict the place and date of the next cataclysm, but even in the XXI century, relying on predictions based on observations and models, is not necessary.
For example, a monstrous earthquake in Southeast Asia, which claimed the lives of about 250-300 thousand people and has become one of the three most powerful in modern history, it was a complete mystery to seismologists.As the appearance of the devastating tsunami resulting from the Japanese earthquake of 2011.
