For some reason, humanity believes that it conquered nature, but this is just an illusion. First, people know more about space than about the world's oceans. Secondly, natural disasters still cannot be predicted by scientists in advance. The consequences of earthquakes are terrible. Photos from disaster sites fly around the world every few years. It terrifies how insignificant man is in front of nature.
Earthquakes - causes and essence
We are used to the fact that the soil under our feet is something immovable and unshakable, but it is not so at all. Tectonic plates located in the earth's crust are in constant motion, collide, diverge, crawl onto each other and rub. In addition, mining in the bowels of the planet, explosions, landslides, filling reservoirs and many other artificial processes can also trigger major earthquakes. In fact, they are tremors and occur quite often - about once every 2 weeks.
However, most of them are on the ocean floor and have not too much power, so they are almost invisible. But if the epicenter is close enough to the surface and populated areas, and the intensity is high, the consequences can be disastrous.
Predictions of Seismologists
Protecting the population from the effects of an earthquake begins by predicting its probability and calculating the time when it will occur. Here you can not do without the achievements of seismology, which managed to develop some methods of predicting earth tremors of sufficient strength to affect the lives of people.
The earthquake itself is preceded by some processes in the lithosphere, which can be tracked and analyzed, which this science does. There are special instruments - seismographs that record the movement of tectonic plates. Their help in predicting strong earthquakes is priceless, because they provide an opportunity to prepare for a disaster, they win a few hours so that you can start the evacuation and warn the population about the danger, which will reduce the number of victims.
The most earthquake-prone areas
The places where earthquakes occur are most often known, this is understandable from the causes of their occurrence. These are the joints of tectonic plates, which on the surface can look like young high mountains, for example, the Himalayas, Andes, Cordillera. In addition, there is a fault in the Far East, it runs from Kamchatka along Japan and stretches further to the islands of Indonesia and New Zealand. From Greece to the southeast, the border of plates also leaves, which carries a potential danger. And all this is not just curious knowledge. This allows the construction of cities, large buildings, etc., taking into account such important information. And not only apply special technologies, but also constantly be on the lookout, be ready to cope with the elements. And this is not always easy, because protecting the population from the effects of an earthquake should be comprehensive. Ultimately, much depends on the scale of the disaster.
Effects
If you take into account only strong and large earthquakes, on their example the damage is obvious. The shift of the earth's crust in different directions provokes damage and destruction of buildings, roads and other objects. This can cause injuries and deaths. That is why, first of all, immediately after the disaster, all the forces of the rescuers are directed to such an event as protecting the population from the effects of the earthquake.
The main damaging factors for this type of emergency are seismic waves of various types:
- Hypocentric longitudinal. Spread from the source in all directions with the alternate formation of compression and extension zones. Soil displacement occurs along the direction of the waves. The speed is about 8 km / s.
- Hypocentric transverse. Also spread in all directions at a speed of 5 km / s and the formation of shear zones. The soil moves perpendicular to the direction.
- Waves of Rayleigh and Love. Spread from the epicenter in the upper layer of the earth's crust. Displacement occurs in the vertical and horizontal direction perpendicular to the waves. The speed is from 0.5 to 2 km / s.
In addition, the effects of earthquakes on humans depend on the area in which they occur. They may be accompanied by avalanches, mudflows, floods, etc., depending on what natural and man-made objects suffered damage. Finally, the number of victims is also affected by the effects of the population during an earthquake. If people know how to behave properly, they will not only survive on their own, but will also help others.
Quality characteristics
Naturally, magnitude and intensity of exposure also matter. To assess them, the Richter scale and several point systems used in different countries are used respectively. There are 12 levels in Russia:
- 1 point It is registered only with the help of special devices.
- 2 points. It can be felt by sensitive animals and people on the last floors of high-rise buildings.
- 3 points. Feels inside some buildings. Vibration is comparable to a truck ride.
- 4 points. It is felt by many people, there may be a swing of doors and windows.
- 5 points. Minor damage: swaying hanging objects, shedding whitewash, rattling glass.
- 6 points. Small cracks in the plaster, brickwork may be observed.
- 7 points. It is characterized by severe damage to buildings, the appearance of cracks in moist soils.
- 8 points. Serious damage to buildings, the destruction of their elements.
- 9 points. Collapses in some buildings and landslides.
- 10 points. The destruction of many buildings. Cracks in the ground up to 1 meter wide.
- 11 points. Complete destruction of all buildings, numerous faults in the ground.
- 12 points. Catastrophic destruction and changes in the lithosphere. Deviations during the rivers.
It is obvious that at an intensity of about 4-5 points and below, protection of the population from the effects of earthquakes is not required, since they are minimal. Nevertheless, it is still worth knowing how to deal with disasters of this kind.
What to do?
Now that the causes and consequences of the earthquakes have become clear, it’s worth talking about how to behave if the earth literally leaves under your feet.
First of all, you need to try to pull yourself together and calm down - you need to act reasonably and soberly, not succumbing to panic. If the disaster is on the street, you need to find a place away from buildings and power lines. If tremors began during a stay in a room, the actions of the population during an earthquake depend on what kind of structure it is. It is better to leave the 2-3-story building as quickly as possible, otherwise, if time permits, you need to open the door, which can then be jammed, and then find shelter. A place near the main wall is well suited, far from the windows; often a table, under which you can hide, or a bathtub will be a great option. The main thing is to stay away from loose objects, windows, etc. Of course, when it comes to transport, when shocks occur, you need to leave it immediately.
Following actions
First of all, protecting the population from the consequences of an earthquake consists in its emergency evacuation and the beginning of work to save those who may be under the rubble. It must be remembered that tremors can be repeated, exacerbating destruction or causing new ones.
The main tasks of the EMERCOM of Russia, like any other rescue service, in such a disaster - to protect people. Rescuers provide first aid, manage the evacuation, clear the rubble. This applies not only to earthquakes, but also to any other emergency situations.
Preventive action
A significant role is played by measures that are taken even before the earthquake. This includes not only government funding for research and the work of seismologists, but also the construction of buildings, dams, protective structures using special technologies.
It is highly recommended that people living in the danger zone have a supply of food, water and medicine at home, study the home in advance for the most suitable place for shelter, and also organize the opportunity to receive information in any conditions, including in the absence of electricity, for example through battery powered radio. It is also worth making sure that all furniture, especially heavy, is in a stable condition. It should be remembered that protecting the population from the effects of an earthquake primarily depends on the people themselves and their willingness to act quickly and correctly. So it will not be amiss to occasionally conduct training events and trainings.
Major earthquakes in recent years
In the XXI century there are 7 destructive disasters associated with the movement of tectonic plates. All of them were quite powerful and intense, had considerable magnitude and caused many thousands of injured and victims:
- 12/26/2003, Iran. Magnitude - 6.3. The death toll is estimated at 50-60 thousand people.
- 12/26/2004, The Indian Ocean. Magnitude - 9.3. About 200-250 thousand victims.
- 05/12/2008, China, Sichuan Province. Magnitude - 8.0. Up to 70 thousand dead.
- 01/12/2010, Haiti. Magnitude - 7.0. About 220 thousand people died, another 300 thousand were injured, more than 1 million lost their homes and property.
- 02/27/2010, Chile. Magnitude - 8.8. It was accompanied by a tsunami. Less than 1000 died, about 1.5 million homes damaged.
- 03/11/2011, Japan. Magnitude - 9.0. Less than 15 thousand people died, about the same number went missing. The earthquake was accompanied by serious damage, a tsunami.
- April 25-26, 2015, Nepal. Magnitude - 4.2-7.8. A series of earthquakes, which killed about 5 thousand, another 7 wounded.
The number of victims is not always directly dependent on the scale of the disaster. Often, the sensible actions of the population during an earthquake can save many lives. That is why informing people about how to behave in emergency situations should be constant and complete. The main task of the Ministry of Emergencies of Russia also includes this item, but earthquakes in the Russian Federation are quite rare. Perhaps neglecting this obligation may one day cost a lot of sacrifice.