It is impossible to imagine a more destructive and dangerous natural disaster than an earthquake. People living in seismically dangerous areas are at risk of getting into the epicenter of earthquake throughout life. The population living in a relatively stable area is afraid of echoes of the movement of the earth’s crust, like waves diverging from the center of the event to its periphery.
Natural causes of earthquakes
In ancient times, disaster was considered the wrath of the gods, a manifestation of the power of other magical and mythical characters. Thanks to modern research and the development of seismology, the causes of oscillations in the lithosphere are clearly defined:
subduction. The upper shell of the earth is made up of slabs. For reasons of internal work taking place in the mantle, these plates can move apart or, conversely, crawl on top of each other, which leads to destructive catastrophes;
plate deformation. Certain forces affect the stability of the platforms themselves, as a result of which an earthquake can occur not only on the periphery, but also in the center of the plates, as, for example, in China;
volcanic activity. Volcanic eruptions also contribute to the occurrence of fluctuations in the earth’s crust. Such phenomena occur more often, but have less destructive power.
Technogenic causes of disasters
Mankind is actively intervening in nature, trying to reshape the environment at its own discretion, without thinking about global changes leading to an increase in the number of natural disasters. So, the following activities of the “king of nature” influence the frequency of earthquakes:
creation of artificial reservoirs on large areas. With the concentration of a huge water mass in reservoirs, its weight begins to put pressure on porous subsurface rocks, causing compaction of the latter. The quality of the sole soil also changes, it becomes too saturated with moisture. All this leads to tremors even in those areas that have never been famous for earthquakes;
ultra-deep drilling and filling of used wells with water. A change in the internal state of the lithosphere due to mining during mining leads to tremors of varying power as you know, nature does not like emptiness;
nuclear explosions, both underground and on the surface of the planet, creating a powerful shock wave and shaking all layers of the Earth’s upper shell.
All these are the main natural and man-made causes of earthquakes.