Geological character of the emergency

Volcanic eruptions, earthquakes, mudslides, landslides, landslides, snow avalanches, karst phenomena with the sedimentation of the earth's surface - all these natural disasters are geological disasters. Some of the natural disasters can be predicted, most can not. But to study the rules of behavior under such circumstances is necessary from the childhood. This article can be useful to the teacher, who compiles a summary of the lesson on the OBL "geological emergency".

Earthquake

Sudden displacements and ruptures of the earth's crust or upper mantle, as a result of which earth tremors with fluctuations of the earth's surface occur, transmitted over huge distances as elastic vibrations, is an earthquake. Such a plan of geological character is usually in three phases - fortshocks, the main push and aftershocks.

The shocks and waiting time between them are very different. The main one is characterized by the greatest strength, and in duration it usually is only a few seconds, but people feel it as very long. Aftershocks produce an even greater mental shock: people feel the inevitability of unhappiness, are chained by fear, inactive, and one must defend themselves and look for safe places.

Measurement of force

Where there is a major release of energy in the volume of the Earth's mass, there is an earthquake focus. The hypocenter, or its focus, is a conditional point in the center of the focus, and the projection of the hypocentre on the surface is the epicenter, around which the greatest destruction takes place. The earth is never at rest, the same earthquakes are recorded every year by many hundreds of thousands, but for the most part they are so weak that people do not even notice them.

That is, it is not a geological emergency. Points that measure the intensity of an earthquake are calculated according to the amount of damage on the surface. This is the most widely used Richter scale, as well as the International scale for measuring the strength of earthquakes. Magnitude is called the characteristic of the total energy of elastic vibrations, which caused this natural disaster.

Earthquakes in Russia

On the territory of our country, twenty-eight percent of the areas are quite seismic. The most frequent geological disasters are in Kamchatka, in the Baikal region, in South Siberia, in the Kuril Islands and in the North Caucasus. Protection from such disasters is an acute problem. Anti-seismic events are divided into two groups - preventive and immediately before and during the earthquake. Preventive measures - this is prevention, which is carried out before the threat of a natural disaster.

Scientists study the phenomena in which geological natural disasters of a natural nature occur , disclose their mechanisms, identify all harbingers of trouble and develop methods of forecasting. And when the "thunder has already burst out," you just need to save people - littered in their homes, left homeless. Settlements and enterprises should be built taking into account the seismic resistance of the area - this is primarily. Otherwise, great calamities will bring geological disaster, examples of the Armenian Spitak are unlikely to be forgotten soon. The population needs to be taught the correct behavior, the level of organization of rescue work should also be on top. The warning system is one of the main conditions for the absence of many victims.

Eruption

Active in the depths of the Earth are active processes, the result of which is active volcanic activity. Eruptions threaten the two hundred million people who live too close to the uninhabited volcanoes. ES geological character, examples of which we find even in ancient times (the death of Pompeii), is associated with the displacement of the earth's crust of magma, that is, with volcanism. Magma - in translation from Greek "thick ointment" - is a molten silicate mass, that is, stones that are heated to fluidity at the highest temperature in the depths of the Earth.

If these magma masses reach the surface, as a result of the enormous pressure from within, an eruption starts, and the glowing streams of liquid stone float on the ground, destroying everything in its path. This is the so-called lava, that is, magma, from which huge amounts of various gases have already volatilized, often poisoning all life, and carried with them for many kilometers and permanently covering the sunlight of the clouds of ash.

Volcanoes in Russia

The characterization of an ES of a geological nature, such as a volcanic eruption, can be given with a full understanding of the nature of this phenomenon. In the earth's crust, after the formation of the planet and cooling it formed numerous channels and cracks, where the magma approaches very close to the surface. And at some point from magmatic foci, located at a depth of about sixty kilometers, as a result of tremendous pressure, magma begins to flow. So volcanoes are formed - separately standing mountains that have created themselves from the products of their own eruptions.

There are volcanoes of three types: extinct, asleep and acting. Those who have fallen asleep are an obscure threat, because there is no information about their eruptions, but local earthquakes are happening under them, that is, at any moment when they rock harder, the volcano can wake up. Extinct - inactive volcanoes, they even very often lost their form. The active ones are a constant source of danger in view of the probability of eruption.

Jelestone and other super-volcanoes

There are also super volcanoes, as, for example, in the American Yellowstone. There are about twenty such on Earth. They sleep for a very long time - sometimes millions of years. But when they wake up, it is no longer the local importance of natural disaster of natural geological nature. Examples of glacial periods speak volumes. The last eruption occurred in New Zealand twenty-seven thousand years ago. Ash covered the ground with a layer of many meters, and also closed the sun for several years. It was thrown into the atmosphere about one thousand two hundred square kilometers.

The concentration of ash, even from an ordinary volcano, is sometimes so great that a few days are dark as at night. Then night came on all the earth and it lasted not the days but the years. Plus, three billion tons of sulfurous anhydride has blown in the air over almost the entire earth. Sulfuric acid rains began, under which all the vegetation was dying. The earth lost up to eighty-five percent of the species of birds only. Those that live in our day - a pathetic fifteen percent of the former magnificence. And the main thing is that it is almost impossible to fight even with the usual active volcano, even from the awakened super volcano, it will not even be possible to escape - there is nowhere. And now try calling the geological emergency more terrible than this.

Landslide

Landslides are found in our country everywhere in areas where there is no evenness of the landscape. The types of CS of geological nature are numerous and diverse, and landslides are not considered to be the most dangerous. Although unexpected - there are. Why is it that under the weight of the ground, huge slopes of mountains and hills slide down, slipping, sea, lake and river terraces?

The stability of the slope is violated, because the cohesiveness of rocks or ground is unexpectedly less than gravity. Then the slope comes into motion. This is not so much a disaster in which thousands of people are killed, but the damage is very great: homes are destroyed, communications are buried, tunnels and pipelines no longer exist, especially electric grids and telephone cables.

What causes landslides?

The factors that can cause a landslide can be different, and very often such a factor is human activity. This is the watering of the soil, the destruction of vegetation (deforestation) or the change in the type of plantations, weathering and, again, earthquakes that cause landslides almost always. Their three types are fast, medium and slow. Only with rapid landslides, many people die. There are also differences in the depth of the slip surface: small - up to five meters, surface - up to a meter, deep - up to twenty meters and, accordingly, very deep - over twenty.

The thickness of the rock mass involved is also graded: small landslides take up to ten thousand square meters of soil, large to one million. However, not only on earth such natural geological disasters occur. Examples are confirmed by the tremendous destruction from the tsunami, which are most often formed as a consequence of an underwater landslide, which in turn occurred after an earthquake. Sediments of sedimentary rocks on the edges of the shelves are very large. In Scotland, after a landslide, prices have demolished everything at a distance of eighty kilometers from the shore.

Celt

The same consequences of earthquakes, mud-stone flows on rough rivers with huge kinetic energy and speed more than fifteen kilometers per hour. According to the power, the mudslides are also divided into groups: if the removal of the mud mass is more than one hundred thousand cubic meters, then this is a powerful sel, there are also medium-sized ones, up to a hundred thousand, and weak ones - less than ten thousand cubic meters of mass.

The danger of mudflows in their suddenness, very rapid growth and duration is sometimes more than eight hours. They can be predicted with some success by analyzing the results of observations. Special hydraulic structures for mud control and selenium control are being constructed. The main thing is not to cut trees on mountain slopes, in the absence of fixation by the root system, the risk of selenium rises many times.

Avalanche

Snowfall, a huge mass of falling or sliding down from the mountain slopes and enthralling more and more new masses. In Europe, the actions of the population in geosciences are quite purposeful, but there are more than one hundred human lives ending every year under avalanches. The destructive power of the avalanche is very great, since it contains a large kinetic energy. They are subdivided by the nature of the movement into bouncing, trays and slopes.

Avalanches are formed mainly on treeless slopes, where the steepness is more than fifteen degrees, but more often it occurs at thirty or forty. If the slope is more than fifty degrees, then avalanches are not formed, since the snow falls to the foot gradually. The speed at it can be beyond - more than hundred meters per second. It is impossible to predict the avalanche collapse. Snow accumulation in dangerous places is simply shot, provoking a gathering, or purposefully blowing up.

Crash

Steep and precipitous mountain slopes are also dangerous for landslides, when large masses of rocks come off and fall as a result of losing their integrity from weathering or under the influence of water - surface or underground, from sudden temperature changes and other natural factors.

Collapses also provoke cyclones and storms, earthquakes and technogenic activity, even the gravitational impact of the moon. In 1995, a large collapse occurred in Ingushetia, its length is one hundred and fifty meters, its width is ten, and its depth is about fifty meters, sixteen people died there. Forecasting collapses is also impossible.

Afterword

Scientific and technological progress can rightly be blamed for the fact that he not only can not protect people and the technosphere from emergencies and natural disasters, but, on the contrary, provokes them himself. The number of victims increases by 4.3% year on year, and the number of victims of destructive natural phenomena is increased by 8.6% annually. Economic losses are also increasing.

This problem is global. The aggravation of natural hazards comes from the growth of anthropogenous influence on the surrounding world, the irrational use of economic objects, the improper resettlement of people, inadequate monitoring of the natural environment, the weakening of systems of observation of natural phenomena by states, the poor condition of protective engineering structures and planted forests. Seismic resistant construction is necessary. Only then will people feel protected during geological disaster. Brief or fluent talk about this problem is impossible.