People who do not have degrees in the sciences, it is very difficult to understand why in the 21st century from the effects of devastating natural disasters: earthquakes and volcanic eruptions killed a lot of people, but science has not yet learned how to predict them.
But even non-specialists understand what causes these natural disasters are linked, and that most of them occur where the ratio of land and sea is constantly changing and there is a process ongoing transformation of the Earth's crust.
Back in the ancient myths and legends, we find mention of the destructive power of earthquakes. This Bible story of the fall of Jericho walls in 1100 BC by thunderous sounds of the sacred pipe. This cleverly inscribed in the "Song of Hiawatha" mention falls celestial stones (meteorites), and earthquakes in the Rocky Mountains. This story of the destruction of Samson Blinded royal palace. Three thousand Philistines were buried under its ruins.
Cause of the Earth's seismic activity, as well as volcanic, to be found in the deepest bowels of the earth — the least studied geology. The main problem in the study is that the deeper wells of 4 km in seismically active areas scientists look failed.
A number of major earthquakes occur in two seismic zones Pacific and the Mediterranean-Trans. In the Pacific area accounts for 80% of all earthquakes in the Mediterranean-Trans — 15%, the remaining 5% occur in the remaining seismic zones.
Since the mid XX century, the USSR, the USA, Japan and China have actively seek methods of earthquake prediction, but the approach was different to the forecast. In the USSR, mostly collected data in seismically active areas. Japan and the U.S. have tried to collect all the available geophysical data.
In China, the People's Army was created observers, with which in 1975 predicted a devastating earthquake with M 7.3 in Haychenge. The city announced the alarm, most of the people had been evacuated. Strong earthquake shock led to the destruction of 90% of all man-made structures.
But next year Tanshanskoe earthquake occurred suddenly. As a result, hundreds of thousands of people were killed.
Many unconfirmed weather causes huge economic damage, and most of the predicted earthquake did not happen. Now use the latest scientific and technical achievements, being of Earth observation satellites, but accurate predictions did not show up.
Earthquakes are the most destructive natural disasters. The effects of seismic activity (fires, destruction of buildings, tsunami and panic) kill the greatest number of people. According to statistics, every year from earthquakes killed more than 10 thousand people, which is 25 times greater than that of volcanic eruptions. The strongest seismic shocks only to the middle of XX century, claimed many lives: in 1923, an earthquake in Tokyo — 140,000 people, in 1946, after the earthquake in Ashgabat — more than 100,000 people.
Scientists are studying earthquake precursors: the water regime, crustal deformation, atmospheric conditions, changes in rock properties and the geomagnetic field, the anomalous behavior of birds and animals.
For some reason they were called, earthquakes are divided into four types.
Volcanic. Tremors volcanic earthquakes occur frequently. Seismic activity occurs in areas of volcanic activity. Since the zone of seismic and volcanic activity are often the same, it is very difficult to determine the type of earthquake. Exactly the type of volcanic earthquakes can speak only in situations where seismic activity is observed simultaneously with increased activity of the volcano.
The consequences of volcanic earthquakes extend not more than 30-50 km near the volcano, the center is located at a shallow depth, and the epicenter is near the cone of the volcano. Energy characteristic of volcanic earthquakes energy blasts, followed by a fast chemical reactions.
Tectonic. Area of impact when tectonic earthquakes may extend to 1500-2000 km, and seismic waves are often run around the entire globe. Consequence is a change in the earth's surface, the emergence of mountains, lakes and valleys of severely damaged homes and buildings. Energy tectonic earthquakes comparable to the energy of nuclear reactions.
Most researchers believe that the cause of seismic activity during tectonic earthquakes is anticlimax induced shift, torsion, or tectonic plates sliding against each other. Proof of the hypothesis is the location of earthquake along existing faults. Repeated faults are the cause for earthquakes. This hypothesis is also supported by the greater intensity of the transverse waves. If the matter were compressed and stretched without breaking, a higher intensity would have the longitudinal waves.
Most disastrous earthquakes associated with alteration of the Earth in the areas of young tectonic folding. With the onset of the critical stress fractures are formed at the time of faulting and seismic tremors occur. Energy for propulsion, evolved at fault (the earthquake) is transmitted through the elastic waves in the earth's crust and comes to the surface, destroying everything. Hypocenters many tectonic earthquakes are located at depths of 10 to 50 km, and some depth. All hubs shocks are on the fault lines in the Earth, and the hypocenters are located on the fault plane, which gradually sink into the bowels of the earth.
Denudation. Processes of landslides in the destruction of the rock temperature fluctuations, water and wind are called denudation. Denudation of the earthquake due to external factors that control the flow of solar heat. Denunatsiya is less than 1% of all earthquakes.
Anthropogenic. Earthquake safe to 4 points can be caused by man-made causes. For example, a large number of weak shocks began to record in some states of America after the start of production of shale gas and heavy oil. In both cases, the technology of hydraulic shock, followed by pumping fluid into the cavity. Several fields of production SG were closed until the reasons.
Oil, gas, coal and diamond deposits can lead to subsidence of different-sized areas. Since the formation of stress in the interior of the earth's crust has been slow, the results of human activity may be seen only through a 500 -1000 years.
Anthropogenic causes also include small bumps following the underground testing of thermonuclear bombs. Furthermore it is known that a large meteorite falling to Earth 65 million years ago caused powerful earthquakes, volcanoes, tsunamis, and led to the extinction of 80% of all life on our planet. It was also observed that the rapid fall or a dramatic surge in air pressure drive the tremors, especially in seismically active areas.
Scientists are monitoring and seismic activity over the communication with the phases of the Moon and the Sun. Especially the influence of the Sun and Moon considerably during the Earth to find the nearest of them away. Set the increased influence of the moon on the occurrence of earthquakes in the full moon and new moon, earthquakes and observed relationship with the density of solar wind emitted by the Sun.
Emergency earthquake is manifested mainly where there is an active fault. In one and the same place catastrophic shocks rarely repeated. For example, until 1948, in Ashgabat, similar in magnitude quake happened in the XIV century. Seismologists believe that the accumulation time voltage is measured at one point thousands of years.
As a result of seismic activity is raising the level of cities such as Stavropol and Tula, Samara and subsidence, Odessa and Baku. In some larger cities, there is a simultaneous subsidence of one part of the city and raising the other. The eastern part of the city goes down, while the western part is gradually lifted.
American geologist Charles Lisa believes that the only consequence of faults and seismic activity caused by other reasons, because of the deeper processes (eg due to sudden changes in the volume of material, the conductivity and the atomic structure of matter.)
But the main reason for seismic tremors — the movement of Earth's core, which is also called the inner sun and the heart of the planet. Our common "heart" theory, we know a lot, but almost — nothing. Without movement of the troublemaker would sustain life on Earth. Stop kernel will cause the disappearance of the magnetic field of our planet. The solar wind can easily penetrate to the Earth, vaporizing all the water and volatiles from the Earth's surface and turning the planet into a desert, similar to Mars.
Nuclear motion ceaselessly transform Earth's surface, and the consequences of these changes bring a lot of suffering humanity. Scientists have enough knowledge about the causes, caused by natural disasters are researching the consequences.
Hopefully, in the near future, researchers will create Earth accurate method of prediction of natural disasters, and earthquakes in the first place.