Where are earthquakes born?
At the end of the 20s of our century, it was found that earthquakes sometimes occur, the sources of which are located at a depth of up to 600-700 km. For the first time they were noted in the marginal zones of the Pacific Ocean. With the accumulation of material, it turned out that earthquakes with a focal depth exceeding 300 km also occur in other areas. the globe. Thus, impacts with a focus depth of 250-300 km occurred in the Pamirs, in the Hindu Kush, Kuen-Lun and the Himalayas, as well as in the Malay Archipelago and in the southern part of the Atlantic Ocean.
Observations show that the sources of strong earthquakes are often shallow. So, for the years 1930-1950. The sources of 800 strong earthquakes were located at a depth of less than 100 km, 187 - at a depth of 150 km, 78 - at a depth of 250 km. During the same time period, only 26 strong earthquakes occurred with a source depth of 300 km, 25 with a depth of 450 km, 39 with a depth of 550 km, and 9 with a depth of 700 km. At the same time, it should be noted that determining the depth of earthquake sources presents even greater difficulties and is far from always unambiguous. Records of the weak
deep shocks are very difficult to detect on a seismograph and decipher.
At present, according to the depth of the source, earthquakes are divided into three groups: normal, or ordinary, with a source depth of up to 60 km; intermediate - with a focus depth of 60-300 km; deep-focus - with a focus depth of 300-700 km. However, this classification is somewhat arbitrary. The point is that if normal and deep-focus earthquakes differ in qualitatively different phenomena occurring in the Earth's crust and in the Earth's mantle, then there are only purely quantitative differences between intermediate and deep-focus earthquakes.
Therefore, it is more correct to divide earthquakes, depending on the depth of the source, only into two groups: intracrustal earthquakes, the sources of which are located in the earth's crust, and subcrustal ones, the sources of which are located in the mantle.
An earthquake is just a shaking of the ground. The waves that cause an earthquake are called seismic waves; like the sound waves that radiate from the gong when it is struck, seismic waves also radiate from some source of energy somewhere in the upper layers of the earth. Although the source of natural earthquakes occupies a certain volume of rocks, it is often convenient to define it as the point from which seismic waves radiate. This point is called the focus of the earthquake. During natural earthquakes, of course, it is located at some depth under earth's surface.
In artificial earthquakes, such as underground nuclear explosions, the focus is close to the surface. The point on the earth's surface directly above the focus of an earthquake is called the epicenter of the earthquake. How deep are the hypocenters of earthquakes in the body of the Earth? One of the first startling discoveries made by seismologists was that although many earthquakes are at shallow depths, in some areas they are hundreds of kilometers deep. Such areas include the South American Andes, the islands of Tonga, Samoa, the New Hebrides, the Sea of Japan, Indonesia, the Antilles in the Caribbean; in all these areas there are deep ocean trenches.
On average, the frequency of earthquakes here decreases sharply at depths of more than 200 km, but some foci even reach depths of 700 km. Earthquakes that occur at depths of 70 to 300 km are quite arbitrarily classified as intermediate, and those that occur at even greater depths are called deep focus. Intermediate and deep-focus earthquakes also occur far from the Pacific region: in the Hindu Kush, Romania, the Aegean Sea and under the territory of Spain. Shallow shocks are those whose centers are located directly under the earth's surface. It is small-focus earthquakes that cause the greatest destruction, and in the total amount of energy released throughout the world during earthquakes, their contribution is 3/4. In California, for example, all earthquakes known so far have been small-focus.
In most cases, after moderate or strong small-focus earthquakes in the same area, numerous earthquakes of lesser intensity are observed for several hours or even several months. They are called aftershocks, and their number during a really large earthquake is sometimes extremely large. Some earthquakes are preceded by preliminary shocks from the same source area - foreshocks; it is assumed that they can be used to predict the mainshock. 5. Types of earthquakes Not too long ago, it was widely believed that the causes of earthquakes would be hidden in obscurity, since they occur at depths too far from the range of human observation.
Today we can explain the nature of earthquakes and most of their visible properties from the standpoint of physical theory. According to modern views, earthquakes reflect the process of constant geological transformation of our planet. Consider now the accepted theory of the origin of earthquakes in our time and how it helps us to better understand their nature and even predict them. The first step towards the perception of new views is to recognize the close relationship in the location of those areas of the globe that are most prone to earthquakes, and geologically new and active regions of the Earth. Most earthquakes occur at plate margins: we therefore conclude that the same global geological or tectonic forces that create mountains, rift valleys, mid-ocean ridges, and deep sea trenches are also the primary cause of the strongest earthquakes.
The nature of these global forces is currently not entirely clear, but there is no doubt that their appearance is due to temperature inhomogeneities in the body of the Earth - inhomogeneities arising due to the loss of heat by radiation into the surrounding space, on the one hand, and due to the addition of heat from the decay of radioactive elements, contained in rocks, on the other. It is useful to introduce the classification of earthquakes according to the method of their formation. Tectonic earthquakes are the most common. They occur when a rupture occurs in rocks under the action of certain geological forces. Tectonic earthquakes are of great scientific importance for understanding the interior of the Earth and of great practical importance for human society, since they are the most dangerous natural phenomenon.
However, earthquakes also occur for other reasons. Tremors of a different type accompany volcanic eruptions. And in our time, many people still believe that earthquakes are mainly due to volcanic activity. This idea goes back to the ancient Greek philosophers, who drew attention to the widespread occurrence of earthquakes and volcanoes in many areas of the Mediterranean. Today we also distinguish volcanic earthquakes - those that occur in combination with volcanic activity, but consider that both volcanic eruptions and earthquakes are the result of tectonic forces acting on rocks, and they do not necessarily occur together.
The third category is formed by landslide earthquakes. These are small earthquakes that occur in areas where there are underground voids and mine workings. The immediate cause of ground vibrations is the collapse of the roof of the mine or cave. A frequently observed variation of this phenomenon is the so-called "rock bumps". They happen when the stresses that arise around a mine working cause large masses of rocks to abruptly, with an explosion, separate from its face, exciting seismic waves.
Rock bursts have been observed, for example, in Canada; they are especially frequent in South Africa. Of great interest is the variety of landslide earthquakes that sometimes occur during the development of large landslides. For example, a giant landslide on April 25, 1974, on the Mantaro River in Peru generated seismic waves equivalent to a moderate earthquake. The last type of earthquakes are artificial, man-made explosive earthquakes that occur during conventional or nuclear explosions.
Underground nuclear explosions, carried out over the past decades at a number of test sites in different parts of the globe, have caused quite significant earthquakes. When a nuclear device explodes in a well deep underground, a huge amount of nuclear energy is released. In millionths of a second, the pressure there jumps to values thousands of times higher than atmospheric pressure, and the temperature increases in this place by millions of degrees. The surrounding rocks evaporate, forming a spherical cavity many meters in diameter. The cavity grows while the boiling rock evaporates from its surface, and the rocks around the cavity are pierced by tiny cracks under the action of the shock wave.
Outside this fractured zone, sometimes measured in hundreds of meters, compression in the rocks leads to seismic waves propagating in all directions. When the first seismic compression wave reaches the surface, the ground buckles upward and, if the wave energy is high enough, surface and bedrock can be ejected into the air in a sinkhole. If the well is deep, then the surface will only slightly crack and the rock will rise for a moment, only to then collapse again onto the underlying layers. Some underground nuclear explosions were so strong that the seismic waves propagated from them passed through inner regions Earth and were recorded at distant seismic stations with an amplitude equivalent to earthquake waves with a magnitude of 7 on the Richter scale. In some cases, these waves have shaken buildings in outlying cities.
Seismic events, no matter how strange it may seem to a resident of the East European Plain, are ordinary and natural manifestations of the life of our planet. Every minute, 1-2 earthquakes occur on Earth, which amounts to several hundred thousand per year, of which one is catastrophic, about ten are highly destructive, about a hundred are destructive, and about a thousand more are accompanied by minor damage to structures. Today it is enough to look at the Internet to be convinced that the earth constantly trembles under the feet of the inhabitants of the most different countries and all continents.
The author of these lines twice had a chance to witness devastating earthquakes. From June 12 to the end of October 1966, I worked as part of a geological team in the vicinity of Tashkent, and in addition to numerous small shocks, I experienced two seven-point shocks (June 29 and July 4). And in the late evening of July 15, for more than an hour, my colleagues and I observed a bright circular glow in the sky (this often accompanies strong earthquakes). I also remember night patrols in Tashkent, daily reports on the strength of seismic tremors, and very intensive, well-organized work to clear the rubble.
In May 1970 on railway station Derbent in Dagestan, I found myself in a military train, which stood for several hours due to the fact that mountains of grain were burning on the tracks, abundantly watered with oil products that had flowed out of the tanks of two colliding trains. The accident happened just before our arrival. The culprit of the collision was an eight-magnitude earthquake.
And eleven years later, in August 1981, I had a chance to experience an eight-point push directly. We then carried out expeditionary work in the Kuril Islands on the slope of the Tyatya volcano on the island of Kunashir. Suddenly, the ground hummed underfoot, and the hard-packed dirt road turned into a swampy abyss for a few seconds. For the rest of my life, memories of the earth leaving from under my feet, the feeling of the unreality of what is happening and the detachment of consciousness, a violation of the perception of time remained in my memory ...
Later it turned out that I witnessed two earthquakes, which played an important role in establishing a connection between seismic events and increased deep degassing. During the Tashkent earthquake of 1966, the effect of increased radon degassing was established 2–3 weeks before the seismic event. During the Dagestan earthquake on May 14, 1970, it was possible to measure the concentration of gases in gaping cracks. It turned out that the concentration of hydrogen during a seismic event increases by 5–6 orders of magnitude. Activation of gas release during an earthquake is observed on an area of tens and first hundreds of thousands of square kilometers, in a zone where the force of shocks exceeds 4 points.
The first shock of the Tashkent earthquake occurred early in the morning at 5:22 am. April 26, 1966 Intense fluctuations lasted 6–7 seconds and were accompanied by an underground rumble and light flashes. The focus of the Tashkent earthquake was located directly under the city center at a depth of only 8 km, so the epicenter of the earthquake, whose magnitude was 8 here, coincided with the city center, which suffered the most. A large number of residential buildings were destroyed, especially the old adobe buildings. Naturally, the first morning shock caught the inhabitants of the city in their beds, which led to human casualties. Schools, factories, hospitals and other buildings were destroyed. The main shock was accompanied by repeated ones - they are called aftershocks (from the English aftershock- push after push), - which were recorded for another two years, the total number of which exceeded 1100. The strongest (up to 7 points) were noted in May-July 1966, and the last one on March 24, 1967.
Waves, foci and centers
Term earthquake so successful and capacious that it does not require further explanation. An earthquake occurs as a result of an abrupt release of energy within a certain volume of the earth's interior. This volume or space is called earthquake focus, the center of the focus - hypocenter. The projection of the hypocenter onto the Earth's surface is called epicenter. The distance from the epicenter to the hypocenter is focus depth. The projection of the source onto the surface within which the earthquake has a maximum force is called epicentral region.
The sources of the vast majority of earthquakes are located at depths of up to 50–60 km. In addition, there are deep-focus earthquakes, their foci are fixed at depths up to 650–700 km. They were discovered in the 20s of the last century on the outskirts of the Pacific Ocean. A relatively small number of earthquakes originate at depths of 300–450 km. In addition to the Pacific margins, earthquakes with deep sources (250–300 km) have been found in the Pamirs, the Himalayas, the Kunlun, and the Hindu Kush.
The geographic distribution of earthquakes on the planet is not uniform. Along with aseismic areas, where no significant seismic events occurred in human memory, seismically active areas are clearly distinguished, which look like linearly elongated zones, almost 90% coinciding with areas of active volcanism. This is, first of all, the Pacific "ring of fire" - the junction zone of the ocean with its continental margins. The already mentioned specificity of these zones is the presence of deep-focus earthquakes. Shallow earthquakes constantly occur in rift zones in the arch of the mid-ocean ridges, as well as in continental rift zones, for example, on Lake Baikal. Interestingly, the seismic zones are the Gulf of Finland of the Baltic Sea and the Kandalaksha Bay - White. Here, the strength of earthquakes reaches 7 points, and the events themselves have become more frequent in recent years.
The most active seismic zone on a planetary scale is the so-called Alpine-Himalayan geosynclinal region. It, covering almost half of the globe, stretches from the Atlantic in the west to the Pacific Ocean in the east.
We emphasize that the nature of the geographic distribution of earthquakes, which coincides with the areas of manifestation of modern volcanism and active deep degassing, directly indicates the presence of genetic connection between these catastrophic events.
The energy, instantly released in the focus, is distributed in the surrounding space in the form of elastic seismic waves. Matter reacts to impulse action by changing its shape and volume. Elementary volume changes propagate in rocks in the form longitudinal waves(condensation waves), and the change in shape - in the form shear waves(shear waves). A good example of longitudinal waves is a wave running along a train after a sharp push of a locomotive. Anyone who has been at cargo stations will remember the characteristic sound of a moving train that accompanies a running wave. A transverse wave is similar to a normal string vibration. Seismic waves obey all the laws of wave motion; at the boundaries of the media they are refracted and reflected, and attenuate as they move away from the source. The length of seismic waves varies from hundreds of meters to hundreds of kilometers.
The speed of propagation of longitudinal waves is 1.7 times greater than the speed of transverse waves, therefore they are the first to reach the surface of the Earth, which is why they are also called P-waves (from English primary- primary), and transverse, respectively, S - waves (from English secondary- secondary). The longitudinal waves that arrived first at the epicenter excite surface waves, which are transverse, but, unlike primary transverse waves, have a propagation velocity that is two times lower. In rocky soils, it does not exceed 3.3–4.0 km/s. The amplitude of surface waves does not exceed a few centimeters, and the length reaches hundreds of kilometers. They diverge from the epicenter in all directions and can run around the entire planet, the meeting point of multidirectional fronts is called anti-epicenter.
In the strata of loose or viscous (sands, clays), rocks especially saturated with water, gravity waves, the reason for their occurrence is the disintegration of particles. A certain volume of rock, thrown up by a seismic shock as a whole, returns to its original position under the influence of gravity in the form of separate particles. The speed of gravity waves is 1000 times less than the speed elastic vibrations and is measured in meters per second, but the amplitude can reach tens of centimeters. Thus, during the California earthquake of 1906, surface waves up to 1 m high were noted in some places, and the propagation of waves about 30 cm high and 18 m long was also recorded.
Surface waves and gravity waves cause the most damage, causing visible ground vibrations and bends in rails, pipelines and roads.
Usually surface movements last no more than one minute, and in 1906 the San Francisco earthquake lasted about forty seconds. However, the duration of the strongest earthquake in Alaska in 1964 was five times longer. Then everything subsides, and the waves of the above types are replaced by aftershocks caused by secondary rock movements at the point of initial violation of their integrity or near it. Aftershocks can last for quite a long time, up to several years, and the strength of some of them can be very large. During the day after the earthquake in Alaska in 1964, twenty-eight aftershocks were recorded, ten of which were quite noticeable. Aftershocks make cleanup and rescue work after an earthquake dangerous.
Our scores against their Richter
The intensity of an earthquake is measured in points or express it magnitude. In Russia, a 12-point scale has been adopted, developed by; the gradations of this scale are approved as a national standard. The scale is built on the readings of seismographs, which give the magnitude of the vibrations during shocks, as well as on the sensations of people and the observed phenomena.
A one-point earthquake is called inconspicuous, is characterized by microseismic shaking of the soil, noted only by seismic instruments. In the middle of the scale there is a strong earthquake of magnitude 6. Felt by everyone. Frightened, many run out into the street. There is a strong fluctuation of liquids. Pictures fall off the walls, books fall off the shelves. Pretty stable home furnishings move or tip over. The plaster on the houses, even of solid construction, gives thin cracks. In poorly built houses, the damage is more severe, but not dangerous.
The names of earthquakes with a force of 7 to 11 points are eloquent. They are named accordingly: very strong; destructive; devastating; destroying; catastrophe. The maximum on the scale is a 12-magnitude earthquake. This is severe disaster- changes in the soil reach enormous proportions. All buildings collapse without exception. In the rocky soil covered with vegetation, fault cracks are formed with significant displacement, shifts and ruptures. Numerous collapses of rocks, landslides, shedding of coasts for a considerable distance begin, new waterfalls appear, rivers change the direction of the flow.
This scale is convenient, but non-linear. The ratio of the energy of the strongest seismic catastrophes to the energy of weak earthquakes is estimated at 10 17 . During strong earthquakes, the energy release is 10 23 – 10 25 erg. For comparison, we point out that the energy of the explosion of a 15-kiloton atomic bomb approximately corresponds to a 6-magnitude earthquake.
A more accurate estimate of the energy release is given by the magnitude - a parameter introduced in 1935 by seismologist Charles Francis Richter (Charles Francis Richter, 1900-1985). He defined magnitude as a number proportional to the decimal logarithm of the amplitude (expressed in micrometers) of the largest wave recorded by a standard seismograph at a distance of 100 km from the epicenter. The magnitude of an earthquake on the Richter scale can vary from 1 to 9. The already mentioned 1906 earthquake in San Francisco had a magnitude of 8.3, but caused almost complete destruction and is estimated at 11–12 points.
Killer earthquakes
The number of human lives claimed by earthquakes during the entire existence of mankind is estimated at 15 million. This is 100 times more than the number of victims of volcanic eruptions. The most destructive known earthquakes have been in China. On July 28, 1976, about 160 km southeast of Beijing, in a densely populated area of northeast China, a very powerful earthquake with a magnitude of 8.2, the epicenter of which was in the huge industrial city of Tangshan.
Dwelling houses and shops, institutions and factories turned into piles of rubble. The entire city was almost flattened to the ground. Some areas, located on loose soils, strongly subsided during the earthquake and became covered with many huge cracks. One of these cracks engulfed the hospital building and the overcrowded train. The development of cracks was facilitated by the collapse of old workings in coal mines. The population of Tangshan numbered one and a half million people, but only a very few managed to escape bodily injury. There were no official reports of this disaster from China, but the Hong Kong press reported that 655,237 people died (this number also included earthquake victims outside Tangshan, in particular in Tianjin and Beijing).
The epicenter of an even more devastating earthquake that occurred on January 23, 1556, was also in China, in the city of Xi'an (Shaanxi Province). Xi'an is located on the banks of the great Yellow River, where plains filled with loose sediments alternate with low hills composed of thin loess material. According to eyewitnesses, entire cities sank into the ground, liquefied by vibrations, and thousands of dwellings dug in loose loess hills collapsed in a matter of seconds. Since the shock occurred at 5 o'clock in the morning, most families were still at home and this is undoubtedly connected huge number victims - 830,000. This is the only earthquake in which there were more deaths than in the disaster in Tangshan.
In Russia and the USSR in the post-war half of the last century, the most destructive were Ashgabat (October 1948); Tashkent (April 1966), Dagestan (May 1970), Spitak (December 1988) and Neftegorsk (May 1995) earthquakes, each of which claimed thousands and tens of thousands of human lives, and entire cities were wiped off the face of the earth.
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O. S. Indeikina
Life safety:
test tasks for university students
Cheboksary 2015
UDC 614.084(075.8)
BBK 68.9ya73
Indeikina, O. S. Life safety: test tasks for university students: teaching aid / O. S. Indeykina. - Cheboksary: Chuvash. state ped. un-t, 2015. - 123 p.
ISBN 978-5-88297-282-9
Published by decision of the Academic Council of the FSBEI HPE "Chuvash State Pedagogical University them. I. Ya. Yakovlev” (Minutes No. 10 dated May 29, 2015).
Reviewers:
I. V. Filippova, Candidate of Biological Sciences, Associate Professor of the Department of Technosphere Safety, Deputy Dean of the Automobile and Road Engineering Faculty of the Volga Branch of the Federal State Budgetary Educational Institution of Higher Professional Education “Moscow Automobile and Road Construction State Technical University (MADI)”;
L. A. Alexandrova, Candidate of Biological Sciences, Associate Professor of the Department of Biology and Fundamentals of Medical Knowledge, Chuvash State Pedagogical University named after I.I. I. Ya. Yakovlev.
The manual presents test tasks on the topics of the course "Life Safety" for self-examination and consolidation of the studied material.
The teaching aid is intended for students of higher educational institutions studying in the areas of training "Pedagogical education", "Psychological and pedagogical education", "Designing light industry products", "Technology of light industry products", "Operation of transport and technological machines and complexes" , "Special (defectological) education", "Technosphere safety", "Applied informatics", "State and municipal government”, “Personnel management”, “Physical culture”, “Design”, “Vocational training (by industry)”, “Service”.
ISBN 978-5-88297-282-9 © Indeikina O. S., 2015
© FGBOU VPO "Chuvashsky
state pedagogical
university. I. Ya. Yakovleva, 2015
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TABLE OF CONTENTS
| Introduction ................................................ ............................... | |
| THEME 1. Theoretical basis life safety. Classification of emergency situations .................................. | |
| TOPIC 2. The Russian system of warning and action in emergency situations .............................................................. ................. | |
| TOPIC 3. Natural emergencies ....... | |
| TOPIC 4. Man-made emergencies ...... | |
| TOPIC 5. Emergencies social character. Criminogenic danger …………………………………............. | |
| TOPIC 6. Basics fire safety ……………………….. | |
| TOPIC 7. Transport and its dangers. …………………………..... | |
| TOPIC 8. Economic, information, food security ……………................................................... ................... | |
| TOPIC 9. Public danger of extremism and terrorism.. | |
| TOPIC 10. Problems of national and international security. Civil defense ……………………....................... | |
| TOPIC 11. Modern means of destruction …………….......... | |
| TOPIC 12. Means of individual and collective protection... | |
| TOPIC 13. Providing first aid …………...... | |
| Answers................................................. ................................ | |
| Bibliography................................................ ....... |
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INTRODUCTION
The teaching aid has been compiled in accordance with the requirements of the Federal State educational standard higher vocational education to the content of the discipline "Life safety".
The purpose of this teaching aid is to involve students in self-examination and assessment of their knowledge, as well as to help teachers in compiling and conducting control sections for this discipline. All test questions are divided into topics of the program, and they are easy to navigate by content. The correct answers are given at the end of the collection.
To assess the results of testing students' knowledge, one should be guided by the following standards:
90-100% correct answers - excellent;
76-89% correct answers - good;
60-75% correct answers - satisfactory ;
< 60% correct answers - unsatisfactory .
TOPIC 3. Emergencies
natural character
For each question, select only one answer that you consider the most complete and correct, or several answers if the question is marked with (*). Solve the crossword puzzle and solve situational problems.
1. Hydrological hazards include:
a) a flood
c) an earthquake;
d) an avalanche.
2. Natural hazards include:
a) the collapse of the building;
b) dam break;
c) an earthquake;
d) an explosion in a mine.
3. Geological hazards include:
a) a hurricane
b) an avalanche;
c) high water;
d) an epidemic.
4. On the territory of the Russian Federation, as a result of natural hazards, about _______ emergencies occur annually.
a) 300; b) 1000; c) 100; d) 500.
5.* Marine hydrological hazards include:
a) typhoons
b) tsunami;
c) floods;
d) tornado.
6.* Hydrological hazards include:
a) floods
b) epidemics;
c) earthquakes;
d) floods.
7.* Natural hazards include:
a) dam failure
b) peat fires;
c) floods;
d) building collapse.
8.* Geological hazards include:
a) avalanches; c) tornadoes;
b) sat down; d) tsunami.
9.* Meteorological hazards include:
b) earthquakes;
c) tornadoes;
d) floods.
10. Changes occurring in nature as a result of human activities are called:
a) natural;
b) anthropogenic;
c) natural;
d) environmental.
11. Natural emergencies, in which harmful effects spread rapidly, include:
a) volcanic eruption;
b) an epidemic;
d) flood.
12. Protection from natural hazards through the use of protective structures and various kinds of shelters is called:
a) in advance;
b) active;
c) planned;
d) passive.
13. A significant influence on the occurrence of natural emergencies in the modern world is exerted by ____________ factor.
a) anthropogenic; c) technogenic;
b) ecological; d) space.
14. Protection from natural hazards by intervention in the mechanism of the phenomenon, the construction of engineering structures, the reconstruction of natural objects, is called:
a) mixed;
b) passive;
c) active;
d) perspective.
15. Explosive and impetuous are emergencies of _______ origin.
a) natural;
b) technogenic;
c) ecological;
d) biological.
16. Forest fires, fires of steppe and grain massifs, peat and underground fires of fossil fuels are included in the concept of "____________".
a) natural fires;
b) man-made fires;
c) natural disasters;
d) emergency situations.
17. The source of an earthquake, located at a depth of 70 to 300 km, is called:
a) intermediate;
b) normal;
c) deep focus;
d) small focus.
18. A sudden flow of water in mountain rivers with high level the content (up to 75%) of stones, dirt, sand, soil is called:
a) an avalanche
c) collapse;
d) landslide.
19. Telluric hazardous natural phenomenon is considered:
a) an earthquake c) volcanic eruption;
b) landslide; d) village.
20. An ascending vortex in the form of a cloudy sleeve or trunk, consisting of rapidly rotating air mixed with particles of moisture, sand, dust and other suspensions, is called:
a) a tornado
b) a hurricane;
c) a storm
d) tsunami.
21. The snow mass falling from the slopes of the mountains under the influence of gravity is called:
a) landslide;
b) an avalanche;
c) collapse;
22. A forest fire that burns the living ground cover, forest litter, dead litter, as well as coniferous undergrowth and undergrowth, is called:
a) grassroots;
b) riding;
c) underground;
d) peat.
23. One of the signs of an approaching tsunami is:
a) strong wind from the ocean;
b) sudden rapid withdrawal of water from the shore;
c) an unusually strong tide has begun;
d) continuous rain with sharp gusts.
24. Meteorological hazards include:
a) a hurricane
b) tsunami;
c) an avalanche;
d) flood.
25. Solid atmospheric precipitation falling at negative air temperature:
a) snow groats;
b) hail;
c) freezing rain;
d) drizzle.
26. Forest fire, covering the ground cover, forest litter and canopy of the forest stand, is called:
a) grassroots;
b) underground;
c) riding;
d) peat.
27. A tectonic natural hazard is considered:
a) an earthquake
b) volcanic eruption;
c) an avalanche;
d) landslide.
28. Bacterial infectious diseases include:
a) salmonellosis;
c) candidiasis;
d) amoebiasis.
29. Forced self-evacuation during a flash flood must be started when the water:
a) has reached the first floor of your building;
b) reached you and there was a threat to life;
c) began to rise sharply;
d) flooded the basement of your house.
30. The area of high pressure in the atmosphere with a maximum in the center is called:
a) an anticyclone
b) cyclone;
c) a tornado;
d) a storm.
31. Safe natural shelter outdoors during a hurricane can be:
a) a ravine or other depression in the ground;
b) a big tree;
c) a high fence;
d) the wall of the house.
32. An earthquake with an intensity of more than 11 points on the Richter scale is considered:
a) very strong
b) moderate;
c) catastrophic;
d) devastating.
33. Earthquake energy, which is characterized by the amount of energy released in the earthquake source, is called:
a) amplitude;
c) power;
d) magnitude.
34. Topological lithospheric dangerous natural phenomena relate:
a) landslides, mudflows;
b) cyclones, tornadoes;
c) earthquakes, droughts;
d) volcanic eruptions, tornadoes.
35. The spread rate of a strong forest ground fire is over _______ m/min.
36. Solid precipitation, which most often falls at negative air temperatures in the form of snow crystals or flakes, is called:
a) snow
b) rain
c) hail;
d) drizzle.
37. A tornado (tornado) at a wind speed of 93 m/s causes ______ damage.
a) significant;
b) devastating;
c) average;
d) amazing.
38. The accumulation of ice in the channel, which limits the flow of the river at the end of winter and in the spring, as a result of which the water rises and spills, is called:
a) congestion;
b) high water;
c) a flood
d) congestion.
39. The average long-term water level in rivers, bays and at individual points of the sea coast is called:
a) upper pool;
b) a pier;
c) an ordinary;
d) backed by the pool.
40. Infectious diseases of the respiratory tract include:
b) whooping cough;
c) malaria;
d) cholera.
41. Heterotrophic organisms that cause in humans and animals different kinds mycoses are called:
a) bacteria
b) the simplest;
d) mushrooms.
42. The movement of air relative to the Earth is called:
a) the wind
b) a hurricane;
c) a squall;
43. The main ways to protect the population from atmospheric hazards include (-yatsya):
a) correct installation of lightning rods;
b) introducing reagents into the clouds with the help of projectiles;
c) warning, shelter, evacuation;
44. The source of an earthquake, located at a depth of more than 300 km, is called:
a) deep focus;
b) normal;
c) small focus;
d) intermediate.
45. As a result of heavy snowfalls, which can last from several hours to several days, the following occurs:
a) snow drift;
b) a blizzard;
46. The wind, whose speed is 21-24 m / s, is called:
b) strong wind;
c) strong storm;
d) full storm.
47. With early warning of an approaching tsunami, first of all, it is necessary:
b) open all windows and doors;
c) take all valuables to the top floor;
d) leave the settlement along the riverbed.
48. Gravitational waves of very long length, resulting from the upward or downward displacement of extended sections of the bottom during strong underwater earthquakes, less often during volcanic eruptions, are called:
a) a typhoon b) tornado; c) a storm d) tsunami.
49. An earthquake with an intensity of more than 8 points on the Richter scale is considered:
a) destructive
b) quite strong;
c) catastrophic;
d) moderate.
50. The spread rate of a strong crown forest fire is over ___ m / min.
a) 100; c) 30;
51. Tornado (tornado) at a wind speed of 18 m/s causes ______ damage.
a) significant;
b) weak;
c) average;
d) catastrophic.
52. The main ways to protect the population from atmospheric hazards include (-yatsya):
a) warning, shelter, evacuation;
b) correct installation of lightning rods;
c) introducing reagents into the clouds with the help of projectiles;
d) planting shelterbelts.
53. Hydrological hazards include:
c) tornado;
d) flood.
54. Intensive, relatively short-term and non-periodic rise in the water level in the river, caused by increased melting of snow, glaciers or an abundance of rain, is called:
a) mudflow; c) a flood
b) a storm; d) tsunami.
55.* Animal vector-borne infections include:
a) encephalomyelitis;
b) tularemia;
c) brucellosis;
d) rage.
56. Intestinal infectious diseases include:
a) whooping cough;
c) cholera;
d) dysentery.
57. An earthquake source located at a depth of less than 70 km is called:
a) intermediate;
c) normal;
b) deep focus;
58. Wind, the speed of which is 24-28 m / s, is called:
a) full storm
b) strong storm;
c) strong wind
d) a hurricane.
59. The destruction caused by a tornado, depending on the wind speed, is divided into _______ classes.
60. Marine hydrological hazards include:
a) an avalanche
b) an earthquake;
c) a hurricane;
d) tsunami.
61. The penetration of water into the basements of buildings through the sewer network is called:
a) a flood
b) flooding;
c) high water;
d) flooding.
62.* Alimentary infections of animals include:
a) parainfluenza;
c) brucellosis;
d) tularemia.
63. Infections, the infection of which is carried out with the help of blood-sucking arthropods, is called:
a) transmissible; c) alimentary;
b) respiratory; d) contacts.
64. An earthquake with an intensity of more than 9 points on the Richter scale is considered:
a) catastrophic;
b) devastating;
c) strong;
d) very strong.
65. A tornado (tornado) at a wind speed of 50 m/s causes ______ damage.
a) significant;
b) serious;
c) weak;
d) average.
66. The main cause of hurricanes, storms and tornadoes is:
a) changing solar activity;
b) reduction of the ozone layer;
c) the phenomenon of global warming;
G) cyclic activity of the atmosphere.
67. The flood zone caused by the destruction of a hydraulic structure, where the height of the breakthrough wave is 1.5 m or less, and its speed is 1.5 or less, is called the zone:
a) a flood c) floods;
b) flooding; d) flooding.
68. Early hydrological forecast up to 10-12 days is called:
a) medium term;
b) long-term;
c) short-term;
d) overtime.
69. Small pathogenic microorganisms ranging in size from 0.4 to 1.0 microns, multiplying only in living cells, causing typhus and Q fever in humans, are called:
a) rickettsiae;
b) fungi;
c) bacteria;
d) the simplest.
70. Human viral diseases include:
a) tuberculosis, dysentery; c) encephalitis, hepatitis;
b) encephalopathy, pancreatitis; d) cirrhosis, colitis.
71. An earthquake with an intensity of 7 points on the Richter scale is considered:
a) very strong
b) moderate;
c) strong;
d) catastrophic.
72. A tornado (tornado) at a wind speed of 117 m/s causes ______ damage.
a) destructive
b) incredible;
c) strong;
d) significant.
73. The best shelter from a tornado is:
c) multi-storey building;
d) basement.
74. When warning about approaching tsunami waves, ships should:
a) go to the open sea;
b) stand on the roads in the harbor;
c) anchor at the quay wall;
d) lower all anchors in the center of the port.
75. According to the epizootological classification, all infectious diseases animals are divided into ___ groups.
76. The smallest non-cellular particles, consisting of a nucleic acid and a protein coat ranging in size from 0.02 to 0.4 microns, which cause smallpox and encephalitis in humans, are called:
a) the simplest; c) bacteria;
b) viruses; d) fungus.
77. A point on the surface of the earth, located above the focus of an earthquake, is called:
a) the epicenter
b) a break;
c) a weather center;
d) hypocenter.
78. Tornado (tornado) at a wind speed of 70 m/s causes ______ damage.
a) serious;
b) average;
c) devastating;
d) weak.
79. Striking factor biological weapons is an:
a) pathogenicity;
b) susceptibility;
c) stability;
d) reproduction.
80. Outstanding floods are repeated after ___ years.
81. Acute infectious diseases of people caused by a bacterial infection include:
a) smallpox, rabies;
b) cirrhosis, colitis;
c) meningitis, dysentery;
d) pancreatitis, hepatitis;
82. The flood zone caused by the destruction of a hydraulic structure, where the height of the breakthrough wave is 4 m or more, and its speed is more than 2.5 m / s, is called the flood zone __________.
a) extremely dangerous;
b) dangerous;
c) catastrophic;
d) moderate.
83. The main damaging factor of the flood is:
a) subsidence of the soil;
b) wind surge;
c) flooding of the area;
d) the flow of water.
84. When biological weapons are used, ________ biological damage is formed.
a) territories;
c) water areas;
d) areas.
85. The minimum height of the breakthrough wave and its speed, at which the destruction of buildings and structures are possible, are respectively:
a) 1.5 m and 1.5 m/s;
c) 3.5 m and 3.5 m/s;
b) 2.5 m and 2.5 m/s;
d) 2.0 m and 2.0 m/s.
86. The system of anti-epidemic measures aimed at the complete isolation of the focus of infection and the elimination of an infectious disease is (are) called:
a) an observation;
b) quarantine;
c) sanitary measures;
d) precautionary measures.
87. A scientifically sound prediction of the development of floods, their nature and extent is called _________ forecast.
a) hydrological;
b) meteorological;
c) seasonal;
d) territorial.
88. Solve the crossword "Natural emergencies":
Vertically:
1. Periodically recurring, rather prolonged rise in the water level in rivers, usually caused by spring snowmelt on the plains or rainfall.
3. Strong electrical lightning discharges.
4. The transfer of snow by strong winds over the surface of the earth.
7. A place where magma erupts to the surface.
8. A cruel atmospheric whirlwind that arises in a thundercloud and spreads over the surface of the earth (water) in the form of a dark giant “trunk” sleeve.
9. A tree under which it is dangerous to hide in a thunderstorm.
10. Special sea waves of very great length and height.
13. Sliding displacement of masses of rocks (or other) rocks down the slope under the influence of gravity.
14. Snowstorm with howling wind and blinding snow.
Horizontally:
2. Intense relatively short-term rise in the water level in the river, caused by heavy rains, downpours, sometimes rapid snow melting during thaws.
5. Erupted magma that has lost some of the gases and water vapor it contains.
6. Accumulation of loose ice during freeze-up (at the beginning of winter) in the narrows and on the bends of the river channel, causing the water to rise in some areas above it.
10. Atmospheric disturbance, circular vortex movement of air with reduced pressure in the center.
11. Heaping of ice floes during the spring ice drift in the narrows and on the bends of the river channel, hampering the flow and causing a rise in the water level in the place of ice accumulation and above it.
12. Tremors, shocks and fluctuations of the Earth's surface caused by natural processes occurring in the earth's crust.
15. Wind, the speed of which is more than 32 m/s.
16. Rapid turbulent flow of water with a high content of stones, sand, clay.
17. A mass of snow moving under the influence of gravity and falling down a mountain slope.
18. Rise in the water level caused by the action of wind on the water surface, occurring in the sea mouths of large rivers, as well as on the windward shore of large lakes, reservoirs and seas.
19. Atmospheric disturbance, circular vortex motion of air with increased pressure in the center.
20. Rapid separation (separation) and fall of the mass of rocks (earth, sand, stones, clay) on a steep slope due to loss of slope stability, weakening of connectivity, integrity of rocks.
89. The figure shows a diagram of the ratio of the hypocenter and epicenter of an earthquake, the direction of propagation of seismic waves. Indicate under which letters the hypocenter and epicenter are represented:
As a result of an accident on a heating main in winter (air temperature -25 0 C), 2 residential buildings were left without hot water and heating, in which about 100 people lived. It was not possible to eliminate the accident quickly, the houses were defrosted. It took 4 days to restore the heating network. Some of the tenants moved in with relatives, some settled in the school building, and some remained in their apartments. Material damage was caused to the property of citizens, there were no casualties.
An earthquake measuring 8.1 on the Richter scale occurred in the Indian Ocean north of Simelue Island, north of Sumatra in Indonesia, at a depth of 30 km. The tsunami caused by the earthquake was one of the strongest in history. It hit the coasts of Indonesia, Sri Lanka, South India, Thailand and some other countries and islands. The height of the waves reached 30 m. The waves took from several minutes to seven hours to reach the shores of various territories.
The United States Geological Survey has published the actual number of casualties and the extent of the damage. According to these figures, the tsunami killed 283,100 people, left 14,100 missing and another million people left homeless. In February 2005, the ocean carried 500 dead bodies ashore every day. According to estimates by non-governmental organizations, the identifications were to continue throughout 2005 and into early 2006.
The socio-economic condition of the region instantly deteriorated.
Famine and disease (cholera, typhoid and dysentery) gripped the countries. It is not unfounded to assume that another 300,000 people died in the following year after the tsunami.
According to scientific data, main reason so disastrous consequences is the destruction of human coral reefs, structures of coastal areas.
What is a fire?
a) chemical reaction oxidation, accompanied by luminescence and the release of a large amount of heat;
b) uncontrolled, spontaneously developing combustion, causing material damage, harm to life and health of people;
c) a special case of combustion, occurring instantly, with a short-term release of a significant amount of heat and light;
d) ignition of flammable materials.
civil defense
For each question, select only one answer that you consider the most complete and correct, or several answers if the question is marked with (*).
1. In a market economy, the basis of state finances are taxes, which make up _______ of the budget.
2. Civil defense is:
a) a system of measures to prepare and protect the population and valuables on the territory of the Russian Federation from the dangers arising from the conduct of hostilities or as a result of these actions, as well as to protect against emergency situations in peacetime;
b) a set of measures to prepare for actions to protect the population and territory in the event of an emergency arising during military operations or as a result of these actions;
c) forces and means of the Russian Federation intended to protect the population and valuables from the danger of armed conflicts or as a result of these conflicts;
d) a system of measures for forecasting, preventing and eliminating emergencies in wartime.
a) economic, food, international;
b) social, environmental, informational;
c) economic, military, social and psychological;
d) economic, food, international, military, border, social, environmental, informational and psychological.
4. Provides the potential for the development of the country for a long historical period, as well as the stability and well-being of society - these are:
a) national security;
b) social security;
c) economic security;
d) psychological safety.
5. To organize and conduct the evacuation of the population, the following are created:
a) family hostels;
b) repair and restoration teams;
c) prefabricated evacuation centers;
d) teams.
6. The Commission for Emergency Situations in the university is headed by:
a) rector;
b) manager of the economy;
c) teacher of the BZ course;
d) physical education teacher.
a) the Constitution of the Russian Federation;
b) the Criminal Code of the Russian Federation;
c) the National Security Strategy of the Russian Federation;
d) the Labor Code of the Russian Federation.
8. The time spent by the population in the protective structures of civil defense is determined by:
a) an asylum officer;
b) the facility's civil defense headquarters;
c) the head of the enterprise;
d) the commandant of the asylum.
9.* Into the student and staff protection plan educational institution in the event of an emergency, the following are included:
a) evacuation from the threatened area to a safe area;
b) organization of medical protection;
c) holding an emergency parent meeting;
d) use of personal protective equipment.
10. Being at home, you suddenly hear intermittent beeps of enterprises and cars. Your actions:
a) immediately leave the premises and go down to the shelter;
b) tightly close all windows and doors;
c) immediately turn on the TV, radio and listen to the message;
d) go outside and find out what's going on.
11. Rescue urgent and other emergency recovery work is carried out:
a) day and night in any weather;
b) only during the day in any weather;
c) continuously, day and night, in any weather, in addition to their completion;
d) continuously, day and night.
12.* The signal "Radiation hazard" is given when:
a) the start of work at a nuclear power plant;
b) the threat of application nuclear weapons;
c) the threat of contamination of the settlement with toxic substances;
d) detection of the beginning of radioactive contamination of a given settlement.
13. The general management of the Civil Defense of the Russian Federation is carried out by:
a) the Government of the Russian Federation;
b) Ministry of Civil Defense Affairs;
c) EMERCOM of Russia;
d) emergency situations of the constituent entities of the Russian Federation.
14. Sirens and intermittent beeps of enterprises and vehicles mean a signal:
a) Attention! Danger!";
b) "Attention everyone!";
c) "Alarm!";
d) "Save yourself, who can."
And collective protection
For each question, select only one answer that you consider the most complete and correct, or several answers if the question is marked with (*). Specify the name of the figures and the meaning of the numbers.
1. In premises adapted for shelters that are not equipped with water supply and sewerage, water containers are installed at the rate of __ liters (s) per person per day.
2. Specify the name of the picture and the meaning of the numbers:
Picture: ___________________________________
1. _____________________________________
2. _____________________________________
3. _____________________________________
4. _____________________________________
5. _____________________________________
6. A special structure designed to protect the population from all types of damaging factors of weapons of mass destruction and fires is called:
a) a bomb shelter
b) anti-radiation shelter;
c) asylum;
d) protective cover.
7. Personal protective equipment includes:
a) gas masks;
c) shelter;
d) cellars of houses.
8. The means of collective protection include:
a) asylum
b) respirators;
d) gas masks.
9. The withdrawal of hiding people from the shelter (shelter) is carried out after receiving the signal:
a) end of chemical alarm;
b) air raid warning;
c) release of radiation hazard;
d) clear the alarm.
10. Protective structures with a capacity of 150 to 600 people are called:
a) small;
b) average;
c) optimal;
d) big.
11. Personal protective equipment for infants includes:
a) children's gas masks;
b) a protective camera for children;
c) children's respirators;
d) children's protective suits.
12. Protective structures with a capacity of 600 to 2000 people are called:
a) average;
b) universal;
c) small;
d) big.
13.* Personal protective equipment includes:
a) AI-2; c) respirator "Petal-1";
b) VMP; d) gas mask.
14. The capacity of protective structures is determined by:
a) the amount of food;
b) the number of places for sitting and lying;
c) the number of people who want to save themselves;
d) the number of places to stand.
15. Slots, trenches, structures of the pit type are protective structures of _________ type.
a) sealed;
b) basement;
c) open;
d) closed.
16. Respiratory protective equipment, skin protection equipment, and medical protective equipment are means:
a) personal protection; c) collective protection;
b) medical protection; d) civil protection.
17. Special treatment of terrain, structures and technical means includes:
a) decontamination, degassing, deratization;
b) decontamination, demeurization, disinfection;
c) decontamination, degassing, disinfection, disinfestation, deratization;
d) deactivation, disinfection, deratization.
18. Gas masks are used to protect the respiratory organs of children:
a) PDF–D(2D), PDF–Sh(2Sh);
b) IP-4, IP-5 (M);
c) IP-46, IP-46(M);
d) GP-5, GP-7.
19. Number of sizes of gas masks:
a) 5; b) 4; in 3; d) 6 .
20. Protective cameras for children KZD-4 and KZD-6 are the main means
The existing methods for determining the depth of an earthquake source are based on the use of a hodograph. The simplest of them is to use seismograms of nearby earthquakes. In 1909, the Yugoslav seismologist Mohorovichich showed that during close earthquakes, two phases of longitudinal waves are distinguished on the seismogram - an individual phase R and normal phase R p. First R is the wave coming directly from the hypocenter of the earthquake, while the second R p represents a wave refracted by the first interface, which is relatively shallow. The elasticity of the substance below this surface is greater than in the upper horizons earth's crust, and longitudinal waves, having experienced refraction at the interface, propagate in the lower layer much faster than in the upper one. Individual phase waves propagate in the upper layer. At small epicentral distances (up to 200 km), they arrive first. At large epicentral distances, refracted waves Rn, those that have passed part of the way along the more elastic lower layer overtake the individual ones and are already the first to enter the seismogram. At epicentral distances of about 600-700 km, the beam R itself touches the first interface and will no longer appear independently on seismograms.
According to the difference in arrival time at various stations located within a radius of up to 600 km from the epicenter, phases R and R p using special formulas, you can determine the depth of the earthquake source. Using this method, it has been established that the sources of most earthquakes fixed by these methods are located at depths not exceeding 50-60 km. In addition to these, there are earthquakes, the sources of which are at depths of 300-700 km. These earthquakes, established in the late 20s - early 30s of our century, were called deep focus. Determination of the source depth of deep-focus earthquakes presents great difficulties and is not always solved unambiguously. The increasingly frequent establishment of deep-focus earthquakes in recent years suggests that the technique used does not always make it possible to distinguish an earthquake with a shallow source from a deep-focus one, especially since “telescope” can take place, when the shaking of the crust caused by a deep-focus “impulse” “provokes” a shock in the "center" located close to the surface, and, as it were, obscured by this less deep earthquake.
Observations of recent decades show that the greatest number of earthquakes is associated with shallow depths. Distribution of the strongest earthquakes of the period 1930-1950. depending on the established depth of the focus is presented in table. 27. The table shows a general decrease in the number of strong shocks with depth, especially sharp in the range from 100 to 150 km. The minima of the recorded shocks are associated with depths of 300 and 450 km. The local maximum was recorded at a depth of 600 km, followed by a sharp drop in the number of impacts at a depth of 700 km.
Deep-focus earthquakes were first established on the outskirts of the Pacific Ocean. Subsequently, earthquakes with a focus depth of 250-300 km were noted in the Pamirs, the Hindu Kush, the Kunlun and the Himalayas, as well as in the Malay Archipelago and in the southern part of the Atlantic Ocean.
At present, according to the depth of the focus, earthquakes are divided into normal, or ordinary (with a focus depth of up to 60 km), intermediate (from 60 to 300 km), deep-focus (from 300 to 700 km).
Table 27
Distribution of earthquakes depending on the depth of the source
| hearth depth, | Quantity of ground- | Depth | Quantity of ground- | Depth | Quantity of ground- |
| km | shaking | focus, km | shaking | focus, km | shaking |
| <100 | 800 | 300 | 26 | 550 | 39 |
| 100 | 412 | 350 | 41 | 600 | 57 |
| 150 | 187 | 400 | 45 | 650 | 25 |
| 200 | 137 | 450 | 25 | 700 | 9 |
| 250 | 78 | 500 | 35 |
This classification is somewhat arbitrary. If the distinction between normal earthquakes and deep-focus earthquakes is based on the separation of qualitatively different phenomena occurring in the earth's crust and in the subcrustal matter, then the division of the latter into intermediate and deep-focus is still based on purely quantitative differences.