What is a tsunami definition? Report: The concept of tsunami

Topic: “Protecting the population from tsunamis.”

Developed

life safety teacher-organizer

Municipal educational institution "Gymnasium No. 24"

Medvedeva I.V.

Goals:

- update knowledge about tsunamis

- to help students develop initial ideas about how to protect themselves from tsunamis

- creating conditions for the formation and development of students’ ability to independently acquire and apply knowledge, draw conclusions, and participate in the discussion of a problem.

Tasks:

- teach actions in the event of a threat and during a tsunami

- develop the ability to work with literature, information materials, draw conclusions.

- to instill in students a valuable and responsible attitude towards their health; ability to work in a team to achieve goals

Lesson type: integrated, generalization and systematization of knowledge.

Technologies: developmental training, informational.

Equipment: textbook, notebook, handouts (tests), chemical equipment for conducting experiments, presentation " Power point ", "Physical map of the world", multimedia projector, computer.

Teaching methods and techniques : problematic, explanatory and illustrative.

Forms of organization cognitive activity : frontal, group, individual.

Lesson plan.

I. Organization of the start of the lesson.

Didactic task: prepare students for work in the lesson.

Check students' readiness for the lesson: there should be a notebook, a diary, a textbook, and writing materials on the tables. Distribution of students into groups. (welcome, preparation for the lesson, availability of everything necessary for work in the lesson, emotional and psychological attitude to work)

II. Checking homework completion.

Didactic task: establishing the correctness and volume of homework completed by all students.

III. Preparation for the main stage of classes.

Didactic task: ensuring motivation and acceptance by students of the goal of educational and cognitive activity, updating background knowledge and skills.

At this stage, a connection was made with the material studied earlier, while control was carried out in a playful way.

Life safety teacher: Today we have unusual lesson. There are guests at our lesson. But we work with you as usual.

The topic of today's lesson: “Protecting the population from tsunamis.”

The purpose of the lesson:

Develop an algorithm for action in the event of a threat, during and after a tsunami.

Lesson plan:

1.How to prepare for a tsunami

2. Rules of behavior during a tsunami

3. Rules of conduct after a tsunami

4. Methods for assessing the quality and purification of water in home and natural conditions.

To achieve the goal that we have set for ourselves, you must answer the following questions. Let's remember the basic concepts of the topic. I have a small aquarium with fish. These fish contain questions that need to be answered.

Questions for reviewing the material covered:

1. What is a tsunami? (giant ocean waves, usually resulting from underwater or island earthquakes or volcanic eruptions, are also possible due to coastal collapse).

2. What does the word tsunami mean? (“tsu” - harbor, “nami” - “ a big wave", that is, a big wave in the harbor).

3. The height of the wave above the source in the ocean is? (1-5 m).

4. Wavelength - ? (150-300 km).

5. Spread speed - ? (from 50 to 100 km/h)

6. What determines the wavelength, its height and propagation speed? (from ocean depth: the greater the ocean depth, the longer length wave and the speed of its propagation and the lower the wave height).

7. Classification of tsunamis by cause of occurrence? (caused by underwater earthquakes, caused by coastal earthquakes, caused by submarine and island volcanic eruptions, caused by landslides on the seabed).

8. Classification of tsunamis by intensity? (very weak - I point, weak - II points, average - III points, strong - IV points, very strong - V points, catastrophic - VI points).

9. Basic damaging factors tsunami? (wave impact, erosion and flooding).

10. Secondary consequences of the tsunami? (fires resulting from damage to oil storage facilities, destruction of chemically and radiation hazardous objects, as well as utility systems can cause chemical, radiation or other contamination over vast areas)

Life safety teacher:

Well done, everyone answered their questions. And the guys also found folk saying: “Expect grief from the sea, and trouble from the water.” Does everyone agree with this proverb? Let's divide into two groups: the left side (agrees with the statement), the right side (disagrees with the statement). Students' answers are heard and a discussion is held.

Life safety teacher:I wrote a short poem dedicated to the tsunami. Listen to him.

She comes from afar

Rising upward and raging.

What will this wave bring?

When will it come to the shores?

The blow and the screams

And a prayer -

Wait! Where are you going?

And who sent you like this -

Untamed and cruel.

Barely left -

And came back again

And destruction again

And for a long time there will be people

Restore everything again.

You have the strength

Power, spontaneity...

So what should we do here?

And the answer is simple -

You predict it early

You will save the human race again.

And if suddenly the wave is sudden,

Then you can protect yourself in it - You follow everything that is necessary -

Save yourself, save your friends.

Life safety teacher:

Therefore, guys, today we focus on the fact that if we do not study this topic, then we will not be able to behave correctly in a critical situation. It could be like this: You went with your parents to the coast (on a tourist package) or suddenly changed your place of residence - and there you can easily encounter this formidable natural phenomenon - a tsunami.

1 V. Main stage.

Didactic task: formation of an integral system of leading knowledge on the topic.

When studying new material, interdisciplinary connections were made with chemistry. Problematic and explanatory-illustrative methods were used. When opened educational material A computer and a multimedia projector were used. The guys worked in groups and individually - they conducted experiments on water purification at home and in natural conditions.

Life Safety Teacher:

We remembered the main questions of the previous topic. Therefore, let's move on to studying new material. You are divided into groups. Each group receives a task, works with the textbook, finds the answer to the question, briefly writes down the answer on a piece of paper, and at the board, one of you reads the answer and attaches it to the board.

Igroup:

Rules: “How to prepare for a tsunami?”

1. Follow the tsunami forecast messages and be aware of their harbingers. Remember the tsunami warning signals for your region ("Attention everyone!" signal transmitted by sirens, intermittent horns of businesses and Vehicle, after hearing the signal, turn on the radio, TV and listen to the information and instructions.)

2. Signs of an imminent tsunami: an earthquake that you notice in your home, a higher than usual low tide, the appearance of cracks in the coastal ice in winter, unusual drift of ice floes in calm weather, surges at the edge of the ice.

3. Most dangerous places during a tsunami, these are river mouths, narrowing bays, and straits. Know the boundaries of the most dangerous areas and shortest paths exit to safe places.

4. Have a list of documents, property and medications that you should take with you in case of evacuation. It is better to put property and medicines in a suitcase or backpack in advance.

5. Consider evacuation procedures in advance. At home and at work, do not clutter the corridors and exits with things, cabinets, strollers, bicycles. Make sure all passages are clear for quick evacuation.

IIgroup:

Rules: " How to behave during a tsunami?

1. When you receive a danger signal, respond immediately. If you are in a room, leave it immediately, after turning off the lights and gas, and taking the prepared documents and things. Try to get to the shortest route high place(30-40 m above sea level) or move 2-3 km from the seashore as quickly as possible.

2. If it is impossible to take refuge in a safe place, when there is no time left, go to the upper floors of the building, close the windows and doors. If possible and necessary, move to the most reliable building.

3. If you decide to shelter from a tsunami indoors, remember that the safest places are considered to be near solid internal walls, near columns, and in corners formed by solid walls.

4. If you find yourself outdoors, try to take cover behind a natural rock barrier, behind a solid concrete wall, or climb a tall, sturdy tree.

5. If you find yourself in water, try to get rid of wet clothes and shoes, try to cling to objects floating on the water.

6. Be prepared for the fact that one wave may be followed by several more. If possible, leave the dangerous area.

IIIgroup:

Rules: " What should not be done in the event of a tsunami threat or occurrence?

1. You cannot go down to the sea, look at its exposed bottom and watch the waves: when you see a wave, it will be too late to escape from low-lying places.

2. You cannot meet a wave in space with big amount structures or other objects due to the danger of hitting them.

IVgroup:

Rules: " What should be done after a tsunami?

1. If you waited out the tsunami in a safe place, then do not rush to return home; you need to wait 2-3 hours after the first wave passes.

2. Only after receiving the all clear signal can you be sure that there will be no more waves.

3. When you return to the house, make sure it is strong, check for cracks in the walls and ceilings, check for damage to the foundation, as well as for the integrity of the windows and doors. Wait to check the condition of the electrical wiring and gas pipeline.

Life safety teacher:

Not only ourselves, but also the state takes care of protecting the population from tsunamis.

Early measures to protect against tsunamis:

1. Creation of an observation and forecasting system

2. Prohibition of new construction in hazardous areas

3. Transfer of economic objects to safe places

4. Construction of breakwaters and dams

5. Preparing routes and places for evacuation in advance

6. Preparing the population for action

7. Tree planting.

But, despite these measures, the tsunami dies in the waves a large number of people, animals; she brings great destruction (film).

Life safety teacher:

The largest tsunamis XX and XXI centuries observed:

1. Severo-Kurilsk, 1952 (130 km from Kamchatka)

2. Alaska (1957, 1958, 1964)

4. Coast of Japan (09/06/2004, 01/09/2005)

5. Southeast Asia (Indonesia, Sri Lanka, Thailand, African country - Somalia 12/26/2004)

6. Solomon Islands - 04/02/2007

Students at " Physical map“The largest tsunamis are noted at the board.

Conducting physical education.

Chemistry teacher:

One of the consequences of the tsunami is the disruption of the water supply system. We all know that without water there is no life. A person can live without water for a maximum of a week.Returning home, we must make sure the quality of our water. How can we do this? The guys will show us now.

Student 1:

Cover a glass of water with a piece of paper. Warm it slightly and quickly remove the leaf - a pungent odor indicates that the water is of poor quality.

Student 2: (experience)

Pour water into a glass and leave for several hours - there should be no sediment or films on the surface. Advocacy - the easiest way to purify water. As a result, volatile components are removed, and heavy metal salts settle to the bottom. Water should be settled in open vessels, protected from direct contact sun rays and at least 10 hours Chemistry teacher:

How can you disinfect water at home?

Student 3: (experience)

Pass the water through a household filter (slide). Or you can make the filter yourself. Burn pieces of non-coniferous wood in a sealed container over high heat. Lay the resulting charcoal with several layers of gauze.

Student 4:

Boiling is the most famous and affordable way water purification. The safest water is boiled. Water should be boiled for 5-7 minutes and stored for no more than a day.

Before boiling water, you should keep it in a glass container for at least three hours - during this time, a significant part of the chlorine in the form of gas will leave the liquid.

If you take tap water from the tap and immediately put it to boil, then chlorine will come out of the liquid, but when the water heats up quickly, it accelerates. chemical reactions, and chlorine dissolved in water will only partially come out of it and will have time to combine with organic substances, which are always present in drinking water. Compounds of chlorine with organic matter are poisonous. Of course, when boiling chlorinated water, this poison is formed in seemingly insignificant quantities, but the body, accumulating it, is poisoned. Use only boiled water. Thus, you will protect the body not only from the effects of pathogenic microbes that cause infectious diseases, but also from excess salts.

Student 5:

The bactericidal properties of silver, which perfectly purify water, have long been known. All you have to do is fill a large container with water and place a silver object, such as a spoon or fork, in the bottom. By morning, silver ions will purify the water no worse than any filter.

Student 6: (experience)

Water can be purified by partial freezing. The fact is that the freshest and purest part of the water freezes first, and then the part containing salts and various impurities. In order to carry out this operation, take water after settling, pour it into a bowl or pan and place it on a sheet of plywood or cardboard in the freezer.When the water begins to freeze, the first crusts of ice need to be removed - this is “heavy water”; when the water freezes halfway, pour out the remaining water and rinse the ice cold water. Soon you will have not only clean water, but also melt water, which is considered active water with special beneficial properties (slide).

Chemistry teacher:

You can purify water by distillation and obtain distilled water. But this water contains no salts at all, which are necessary for the functioning of the body.

Life safety teacher:

So, we learned how to check the quality of water and how to purify water at home. Imagine - we evacuated. Lack of water leads to the death of a person within 3 days. Thirst is subjective feeling, which occurs in a person when there is a lack of water in the body. Water supply begins with finding a water source. Most often, there is a water source, but the water in it is unsuitable for drinking (swamp, puddle, etc.) How to purify water in such conditions? We got acquainted with this material during life safety lessons in the 6th grade.

Student 7:

You can purify water by filtration by digging a hole near the water source, and soon enough clean water will be collected in the hole.

Student 8: (experience)

Filtration can also be carried out using primitive filters: in an empty tin can, pierced several times with nails, put cotton wool with gauze or a piece of cloth at the bottom, then put washed coal, which will remain when the fire burns out. Water is passed through this filter and used for drinking.

Student 9:

In a similar way, you can make a tube for drinking water from untreated sources. Gauze or cloth is inserted into a tube made of any material. Then coal and again gauze (matter) on top. Place the tube in your mouth and drink water.

Student 10: (experience)

Water can be neutralized by dropping 8-10 drops of iodine per 1 liter of water, or use potassium permanganate: 1-2 grams per bucket of water, and the color of the solution should be slightly pink, just make sure that the crystals dissolve properly. In extreme cases, even ordinary table salt will help - one tablespoon per 1.5-2 liters of water. In all cases, the water must stand for 15-30 minutes.

Chemistry teacher:

You can use hydroperite tablets: one tablet per 1.5-2 liters of water.

Student 11:

The most the best method Disinfection of water is boiling. A primitive dish can be made from clay, put foil in it and you can boil water in this dish. It should be remembered that the earth is practically not absorbed in the gastrointestinal tract, and if after boiling and settling the water remains cloudy, then you should not be afraid of this, you can drink it.

IV. Consolidation of knowledge.

Life safety teacher:

And now each of you will receive questions for repetition, which are compiled in the form of a test. The first two questions have one answer option, and questions 3 and 4 suggest the order of your actions.

Questions for self- and mutual control:

Part A: questions contain one answer option

1. Are all places safe where you can take shelter from a tsunami:

A) hills and other elevated places with a height of at least 30-40 meters

B) places 2-3 km away from the coast

C) lowlands and ravines at least 2 meters deep

D) corners formed by main walls

2. What not to do if there is a tsunami threat

A) climb to elevated areas 30-40 meters high

B) move 2-3 km away from the coast

C) take shelter indoors near the main internal walls

D) go down to the sea, look at its naked bottom

Part B: arrange the answer options in the order of your actions

3. What to do if you find yourself in a tsunami wave. Your actions:

A) take off your clothes and shoes

B) draw as much air into your chest as possible

C) after waiting out one wave, use the period of time before the next one to exit to a safe place

D) group yourself and cover your head with your hands

D) take advantage of floating and rising objects

4. You are asked to leave the danger zone. Your actions:

A) take the necessary things and documents and immediately head to the collection point

B) strengthen the doors and windows of the lower floors, stock up on food and water in sealed containers.

C) move valuables to the upper floors or attic

D) turn off water, gas, electricity

Life safety teacher:

Let's exchange papers and check that the tasks are completed correctly. Let's evaluate each other's answers.

Right answers:

1. in (1 point)

2. g (1 point)

3. b, d, a, d, c (2 points)

4. d, c, b, a (2 points)

Evaluation criteria:

5-6 points - “5”

4 points - “4”

3 points - “3”

Count in groups how many “5”, “4”, “3” you have.

V . Homework

At the end of the lesson, a home task was given, during which the children must use not only the textbook, but also additional literature to prepare messages

1. Study chapter 7.4 at home (pp. 116-121)

2. Work through and find material on the topic “Forecasting tsunamis and measures to reduce damage from them.”

VI. Summing up the lesson. Reflection.

Didactic task: provide an analysis and assessment of the success of achieving the goal and outline the prospects for subsequent work.

At the end of the lesson, the results of the lesson were summed up and reflection was carried out.

Life safety teacher:

To summarize our lesson, I would like to once again dwell on the algorithm of actions (we change groups and change the task).

Conclusion:

Think and say: “Where in our lesson were interdisciplinary connections used, with which disciplines?”

And remember:

Nature does not accept jokes, it is always truthful, always serious: it is always right, but mistakes and delusions come from people (I. Goethe)

THANK YOU FOR YOUR ATTENTION!

Literature.

1. Bocharov S.V. Chemistry 8th grade: Lesson plans based on the textbook by O.S. Gabrielyan. Teacher - AST, 2003

2. Galkina M.V. Thematic and lesson planning in life safety: 6th grade: to the textbook by M.P. Frolova, E.N. Litvinova et al. “Fundamentals of life safety. 6th grade" edited by Yu.L. Vorobyova / M.V. Galkina. - M.: AST: Astrel, 2008. - 350 p.

3. Malov-Gra A.G. Thematic and lesson planning in life safety: 7th grade: to the textbook by M.P. Frolova, E.N. Litvinova et al. “Fundamentals of life safety. 7th grade” edited by Yu.L. Vorobyova/ A.G. Malov-Gra - M.: AST: Astrel, 2010. - 286 p.

4. Fundamentals of life safety in the lessons of geography, biology, chemistry, social studies, ecology. 6-11 grades/aut.-comp. E.L. Gordiyash. - Volgograd: Teacher, 2007. - 248 p.

5. Fundamentals of life safety: reference book. for students/ A.T. Smirnov, B.O. Khrennikov, R.A. Durnev, E.N. Ayubov; edited by A.T.Smirnova; Ross. acad. Sciences, Ross. acad. education, publishing house "Prosveshcheniye". - M.: Education, 2007. - 224 p.

Origin and classification of tsunamis.
Consequences of the tsunami.
Tsunami forecasting and measures to reduce damage from them.
Rules safe behavior during a tsunami

Slide 2

Tsunamis are giant ocean waves resulting from earthquakes, volcanic eruptions, and sometimes coastal collapses.

Slide 3

Tsunami epicenters

Slide 4

Characteristics of tsunami waves

Slide 5

The main parameters of a tsunami include:

Tsunami speed is the distance a tsunami travels in a certain time;

The height of the sea wave is the vertical distance between the crest and the bottom of the wave;

Sea wave length is the horizontal distance between two peaks or bottoms of sea waves;

The sea wave period is the time interval between the arrival of two successive waves.

Slide 6

Often before a tsunami begins, the water recedes from coastline, exposing the bottom for several kilometers.

Slide 7

Then there is a series of waves with intervals between them of 5 - 90 minutes. The highest height is usually not the first wave, but one of the first ten (the main wave).

Slide 8

Tsunamis are classified by cause of occurrence and intensity.

Slide 9

The destructive power of a tsunami depends on the speed of the wave, the direction of its movement relative to the shore, the contour of the coastline, the topography of the coast, the coastal slope and the shelf.

Slide 10

Lowland coasts are most affected by tsunamis. Although when approaching a gently sloping shore its impact decreases, the flood zone is very large.

Slide 11

Slide 12

Tsunamis are especially dangerous for villages, cities and buildings located on the low-lying shores of the ocean, as well as those located at the tops of bays and bays, wide open to the ocean and tapering wedge-shaped towards land.

Slide 13

Far from the coast, the effect of a tsunami is not dangerous. Therefore, ships that managed to leave the harbor and move far enough from the coast (at least 6-8 km) are not exposed to the destructive waves. However, ships in the ocean above the epicenter of an underwater earthquake causing a tsunami may experience seaquakes.

Slide 14

Measures to reduce tsunami damage

Lesson topic: Tsunami

Lesson type - learning new material

Target:
1. To familiarize students with the dangerous marine hydrological phenomenon - tsunami;
2. Give to students necessary information about the causes of the tsunami and its consequences.
3. Use interdisciplinary connections for conscious perception of the material.
Tasks:
Educational:
- Teach students to act in extreme situations;
- Reveal the causes of the tsunami and the consequences of the tsunami;
- Introduce tsunami parameters and tsunami protection measures
Educational:
- Formation psychological readiness students to act in emergency situations.
- Identifying the creative abilities of students when analyzing the situation and drawing up a plan to overcome it.
Educational :
- Cultivate a sense of self-confidence in extreme situation and responsibility for the lives of other people.
Equipment:
computer, projector, screen.

Lesson plan:

1. Organizing time- 1 minute.

2. Updating interdisciplinary connections - 5 minutes

3. Introductory speech by the teacher - 1 minute.
Presentation of new material, viewing of video presentation – 24 minutes.

4. Fixing the material, execution test task on the computer – 8 minutes. Answers to questions – 2 minutes

5. Lesson summary – 2 minutes.

6. Homework – 2 minutes.

Upon completion of the topic, students should:
a) know:

Methods of warning about the approach of a tsunami;

Damaging factors;

Basic measures to protect the population from tsunamis;

b) have the skills to carry out tsunami protection measures;

c) have an idea of the consequences of a tsunami.

During the classes :

Stage I Organizational moment (1 min.)

Organization of the beginning of the lesson.
The presence of students and the readiness of the class for work are checked.
I announce the work plan - a lesson in learning new material from the emergency section natural character and protecting the population from their consequences.

Stage II Updating interdisciplinary knowledge – (5 min.)

Geography: Waves in the ocean: wind waves, tides, tsunamis.
History: Dates and areas natural disaster in Russia, in the world.

Stage III Learning new material – (24 min.)

Slide 1.
So that the elements do not suddenly overtake,
Trouble did not suddenly strike
We must take measures such as
So that a rebuff will always be ready for her!

Look for solutions to win,
You can't retreat before the elements,
Solidarity with civil defense
It will help you cope with trouble

Teacher's story.

Tsunami is a marine hydrological hazard.
At 4 a.m. on November 5, 1952, residents of the city of Severo-Kurilsk and a number of coastal villages on the island of Parshumir, part of Kuril Islands, were awakened by strong tremors that lasted about half an hour. Earthquakes happen here quite often, and people went back to sleep when the earth seemed to calm down. Soon a loud noise was heard from the sea and a huge wave of water was advancing on the city, which rolled across the island, reached the slope of the hill and rushed back. Half-dressed people fled to the hills to escape the terrible wave. It was an unusually quiet moonlit night.
The first wave of water receded after 15 minutes, and some residents returned to their homes in time to save at least some of their property. At that moment, a second, more terrible shaft 10 meters high came, which destroyed the entire city. Sweeping away everything in its path, a terrible wave carried all city buildings, cars, and agricultural equipment into the sea. The city was filled with the roar of buildings and the screams of dying people.
After the disaster, an empty area of several square kilometers formed on the site of the city. More than 2,000 people died in the city and towns.
This natural disaster, caused by huge waves washing ashore destructive force, is called a tsunami.

Slides 2-4.

Concept - tsunami. Origin and cause of the tsunami. Characteristics of tsunami waves. Classification of tsunamis: according to the reasons for its occurrence; by intensity.

Slides 5.

Basic tsunami parameters..

Slide 6-8.

The most tsunami-dangerous areas of Russia and the world (Kamchatka, Sakhalin, Kuril Islands, coast Pacific Ocean, Indonesia, Chile, Peru, Japan, East Java, Aleutian Islands, Alaska, Hawaiian Islands). Display slide number 17 on interactive whiteboard and mark the most tsunami-prone areas. Show these areas on the world map.

Slides 9-10.

Main damaging factors

Slide 11.

Consequences of the tsunami.

Slide 12.

Early measures to protect against tsunamis.

Slides 13-15.

When receiving the “TSUNAMI COMING” signal. Rules of conduct when receiving a signal about the approach of a tsunami. Rules of conduct in the event of a sudden tsunami approach.

Slide 16.

Rules of behavior after the passage of a tsunami.

Stage IV Fixing the material

Slide 17.
Performing a test task.

You have a test in front of you. Questions may have YES or NO answers. Therefore, be careful. We started completing the task.

Slide 18.

Checking the KEY test

Stage V Lesson summary.

Stage VI. Homework.

Bibliography

1. Frolov M.P. Fundamentals of life safety. – Moscow: AST, 2009.

2. Gerasimova T.P. Beginner course geography. – M.: DROFA, 2010.

Internet resources

1. Video of the tsunami http://rest.msun.ru/rest/tsunami/tsunami.php

2. Photos, illustrations of the tsunami http://cynami.com/

Preview:

To use presentation previews, create an account for yourself ( account) Google and log in: https://accounts.google.com

Slide captions:

Life Safety Tsunami

The concept of “tsunami” Tsunamis are waves in the ocean caused by underwater and coastal earthquakes, volcanic explosions, coastal collapses or large underwater ones. Tsunami is a Japanese word. Pronounced "tsu-na-mee". "tsu" means harbor, "nami" means wave.

Causes of tsunamis:

Causes of a tsunami: 1 the formation of cracks on the bottom 2 the raising (lowering) of part of the bottom 3 the generation of waves by water tending to return to its original state Underwater earthquake

The main parameters of a tsunami: speed (600-1000 km/h); wave height (up to 70 m); wavelengths (up to 1000 km); wave period (from minutes to several hours).

Tsunami-prone areas

Tsunami off the coast of the island. Sri Lanka December 26, 2004 in a satellite image from www.themegallery.com

Coastal changes due to the 2004 Indonesian tsunami

Main damaging factors: Primary: air wave; wave blow; hydrodynamic water pressure.

Main damaging factors: Secondary: flooding of the area; destruction of buildings, structures, communications; beaching of ships; death of people and animals; soil loss, destruction of crops; Soil pollution; contamination or destruction of drinking water sources.

Consequences of the tsunami

Early measures to protect against tsunamis: establishment of an observation and forecasting system; banning new construction in hazardous areas; moving objects to safe places; construction of breakwaters and dams; advance preparation of routes and places for evacuation; preparing the population for action; tree planting.

Upon receiving the signal “There is a tsunami”: forecasting the possible location and time of the tsunami approach; warning the population; urgent departure of ships to the open sea; emergency evacuation of the population to safe places.

Rules of conduct when receiving a signal about the approach of a tsunami: after hearing the sounds of sirens, listen carefully to the message about the time of arrival of the wave and the organization of evacuation of the population to a safe place; take with you a minimum of warm clothes (preferably waterproof), food, money, documents, and valuables; before leaving, turn off the gas and water in the house, turn off the electricity; Without delay, move inland to a hill or 2-3 km from the coast.

Rules of conduct in the event of a sudden tsunami approach: immediately close all windows and doors and go up to the top floor; general rule- do not run out of a solid building; take the safest place in the room - away from the windows near the main wall on the side of the wave's arrival; if a wave catches you on the street, then try to cling to a tree trunk or a concrete wall; get ready for the wave to return.

Rules of behavior after the passage of a tsunami: stay in a safe place for at least 2-3 hours after the arrival of the first wave; wait for the alarm to clear.

SCREENING TEST: 1 . Is a tsunami a wave in the ocean caused by an underwater (coastal) earthquake or volcanic eruption? 2. Is the wave speed near the shore greater than in the ocean? 3. Is the central part of Russia classified as a tsunami-hazardous region? 4. The main damaging factors of a tsunami: air wave, wave impact, hydrodynamic pressure? 5. When receiving a signal about the approach of a tsunami, you must: - take the necessary things, documents, food - turn off the gas, water, turn off the electricity - go 2-3 km inland or to a hill? 6.Do you need to stay in a safe place after the tsunami passes for 12-13 hours? Answer graphically YES or NO

is a dangerous natural phenomenon that represents sea waves, arising mainly as a result of upward or downward displacement of extended sections of the seabed during underwater and coastal earthquakes. Tsunami-hazardous areas of our country are the Kuril Islands, Kamchatka, Sakhalin, and the Pacific coast. Once formed in any place, a tsunami can spread from high speed(up to 1000 km/h) for several thousand kilometers, while the height of the tsunami in the area of occurrence is from 0.1 to 5 meters. When reaching shallow water, the wave height increases sharply, reaching a height of 10 to 50 meters. Huge masses of water washed ashore lead to flooding of the area, destruction of buildings and structures, power and communication lines, roads, bridges, piers, as well as the death of people and animals. In front of the water shaft, air spreads shock wave. It acts similarly to a blast wave, destroying buildings and structures. The tsunami wave may not be the only one. Very often this is a series of waves that roll onto the shore at intervals of 1 hour or more. The possible scale of destruction is determined by the range of the tsunami: weak (1-2 points); average (3 points); strong (4 points); destructive (5 points).

SIGNS OF A TSUNAMI

A natural warning signal of the possibility of a tsunami is an earthquake. Before a tsunami begins, as a rule, the water recedes far from the coast, exposing the seabed for hundreds of meters and even several kilometers. This low tide can last from a few minutes to half an hour.

The movement of the waves can be accompanied by thunderous sounds that are heard before the approach of the tsunami waves. Sometimes, before a tsunami wave, the coast is flooded with a “carpet” of water. Cracks may appear in the ice cover off the coast. A sign of an approaching natural disaster may be a change in the usual behavior of animals, which sense dangers in advance and tend to move to higher places.

PREVENTIONAL MEASURES

Monitor tsunami forecast messages and be aware of warning signs. Remember and explain to your family the tsunami warnings for your area. Have a tsunami plan in advance. Make sure that all your family members, co-workers and acquaintances know what to do during a tsunami. Assess whether your home or place of work is located in the area possible action tsunami. Remember that the most dangerous places are river mouths, narrowing bays, and straits. Know the boundaries of the most dangerous areas and the shortest routes to safe places. Make a list of documents, property and medicines to be removed during evacuation. It is advisable to put property and medicines in a special suitcase or backpack. Think about the evacuation procedure in advance. Decide where your family will meet if there is a tsunami warning. During daily activities at home and at work, do not clutter corridors and exits with bulky things, cabinets, bicycles, strollers. Make sure all passages are clear for quick evacuation. Learn the rules of behavior in the event of a tsunami hazard.

Consider the sequence of your actions if you find yourself indoors, in open areas, or in water during a tsunami. Prepare a place in your apartment in advance where, in case of a quick evacuation, put Required documents, clothing, personal items, a two-day supply of non-perishable food.

Support community programs in preparation for a tsunami, actively participate in planting forest shelterbelts on the coast.

Support efforts by local authorities to strengthen bays with breakwaters and coastal dikes.

WHAT TO DO DURING A TSUNAMI

When a tsunami warning is received, respond immediately. Use every minute to ensure your personal safety and the protection of those around you. You may have anywhere from a few minutes to half an hour or more, so if you act calmly and thoughtfully, you can increase your chances of staying safe from the effects of a tsunami.

If you are indoors, leave it immediately, after turning off the lights and gas, and move to a safe place. Take the shortest route to an elevated place 30-40 m above sea level or quickly move 2-3 km from the coast. If you are driving a car, follow in a safe direction, picking up running people along the way. If it is impossible to take refuge in a safe place, when there is no time left to move, climb as high as possible to the upper floors of the building, close the windows and doors. If possible, move to the most secure building.

If you are sheltering indoors, remember that the safest areas are considered to be places near main internal walls, near columns, and in corners formed by main walls. Remove nearby objects that could fall, especially glass ones. If you do find yourself outdoors, try to climb a tree or take cover in a place that is less susceptible to impact. As a last resort, you need to cling to a tree trunk or a solid barrier.

Once in the water, free yourself from shoes and wet clothes, try to cling to objects floating on the water. Be careful, as the wave can carry large objects and their debris with it. After the arrival of the first wave, prepare to meet the second and subsequent waves, and if possible, leave the dangerous area. If necessary, provide first medical care to the victims.

WHAT TO DO AFTER A TSUNAMI

Wait for the alarm to clear. Return to your original location after making sure that there have been no high waves at sea for two to three hours.

When entering a house, check its strength and the safety of windows and doors. Make sure there are no cracks in the walls and ceilings, and no erosion of the foundations. Carefully check for gas leaks in the premises and the condition of the electrical lighting.
Notify the commission on emergency situations about the condition of your home. Actively join the team in carrying out rescue and other emergency operations in damaged buildings, searching for victims and providing them with the necessary assistance.

28.04.2013 20:59

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On the pages of our website we have already talked about one of the most dangerous natural phenomena- about earthquakes: .

These fluctuations earth's crust often generate tsunamis, which mercilessly destroy buildings, roads, piers, leading to the death of people and animals.

Let's take a closer look at what a tsunami is, what are the causes of its occurrence and the consequences it causes.

What is a tsunami

Tsunamis are high, long waves generated by a powerful impact on the entire thickness of ocean or sea water. The term “tsunami” itself is of Japanese origin. Its literal translation is “a big wave in the harbor” and this is not in vain, since in all their power they manifest themselves precisely on the coast.

Tsunamis are generated by a sharp vertical displacement of the lithospheric plates that make up the earth's crust. These gigantic vibrations vibrate the entire thickness of the water, creating a series of alternating ridges and depressions on its surface. Moreover V open ocean these waves are quite harmless. Their height does not exceed one meter, since the bulk of the oscillating water extends below its surface. The distance between the ridges (wavelength) reaches hundreds of kilometers. The speed of their spread, depending on the depth, ranges from several hundred kilometers to 1000 km/h.

Approaching the shore, the speed and length of the wave begins to decrease. Due to braking in shallow water, each subsequent wave catches up with the previous one, transferring its energy to it and increasing its amplitude.

Sometimes their height reaches 40–50 meters. Such a huge mass of water, falling ashore, completely devastates coastal zone. The extent of the destruction area deep into the territory in some cases can reach 10 km!

Causes of tsunami

The connection between tsunamis and earthquakes is obvious. But do vibrations in the earth's crust always generate tsunamis? No, tsunami are generated only by underwater earthquakes with a shallow source and magnitude greater than 7. They account for about 85% of all tsunami waves.

Other reasons include:

Landslides. Often a whole chain can be traced natural disasters– the shift of lithospheric plates leads to an earthquake, it generates a landslide that generates a tsunami. This is precisely the picture that can be seen in Indonesia, where landslide tsunamis occur quite often.
Volcanic eruptions cause up to 5% of all tsunamis. At the same time, gigantic masses of earth and stone, soaring into the sky, then plunge into the water. A huge mass of water is shifting. They rush into the resulting funnel ocean waters. This dislocation generates a tsunami wave. An example of a disaster of absolutely terrifying proportions is the tsunami from the Karatau volcano in 1883 (also in Indonesia). Then 30-meter waves led to the death of about 300 cities and villages on the neighboring islands, as well as 500 ships.

Despite the presence of our planet’s atmosphere, which protects it from meteorites, the largest “guests” from the universe overcome its thickness. When approaching the Earth, their speed can reach tens of kilometers per second. If such meteorite has a large enough mass and falls into the ocean, it will inevitably cause a tsunami.

Technological progress has brought not only comfort to our lives, but has also become a source of additional danger. Conducted underground testing nuclear weapons, this is another reason for the occurrence of tsunami waves. Realizing this, the powers possessing such weapons entered into a treaty prohibiting their testing in the atmosphere, space and water.

Who studies this phenomenon and how?

The destructive effect of the tsunami and its consequences are so enormous that humanity has become the problem is to find effective protection against this disaster.

The monstrous masses of water rolling onto the shore cannot be stopped by any artificial protective structures. The most effective defense in such a situation can only be the timely evacuation of people from danger zone. For this necessary enough long term forecast impending disaster. Seismologists do this in collaboration with scientists from other specialties (physicists, mathematicians, etc.). Research methods include: