Purpose of the lesson: to introduce students to the concept of volcanoes, the reasons for their eruptions, to understand what volcanoes are and where they are located on Earth. Lesson objectives: - introduce students to dangerous natural phenomenon geological origin of volcanoes, with types of volcanic eruptions and the causes of their occurrence. - develop the ability to correctly assess the situation, the ability to analyze, systematize and draw conclusions; - generate interest in the subject; - teach to resist natural elements.




Oral survey: What activities need to be carried out before an earthquake so that it does not take you by surprise? What safety measures should you take if an earthquake hits you at home? What safety measures should be taken after an earthquake?


“... From that moment, when the day faded and the crimson light of molten lava came into its own, we were transported to a world of magical visions ... The lake of fire cast ominous crimson reflections on the massive walls of the crater. Heavy waves of liquid lava roared and beat dully...


Climbing through the scree, we reached two flaming crevices, from which hot gases burst out with a deafening noise, suffocating from the effort. We measured their temperature - it reached 1000 degrees... Below us, molten lava was bubbling - it was no more than four hundred meters away... The heat was unbearable... We walked on uneven ground; no human has ever set foot on it; it had barely just arisen, it had only recently hardened, the heat of fiery abysses emanated from it...” This is how the Belgian scientist and writer Harun Taziev described his impressions of visiting the volcano crater.


The concepts of “volcano”, “volcanic eruption”, “magma”, “active margins”. Causes of volcanic eruptions. The word "volcano" comes from the name of the god of fire and blacksmithing, Vulcan, from ancient Roman myths. A volcano is a conical mountain from which hot material – magma – erupts from time to time. Magma is formed at high temperatures and pressures in the earth's crust and upper mantle. Scientists believe that the process of magma formation occurs during tectonic movements of lithospheric plates on its active outskirts.


Active margins are areas of the lithosphere where oceanic crust is subducted beneath lighter, more buoyant continental crust, forming an inclined plate. The interaction of a plate of subducting oceanic crust with continental lithosphere causes melting of the upper mantle at a depth of km. The melt drops that originate here, merging with each other, begin to move upward. At some higher intermediate levels in the earth's crust they form magma chambers, and an eruption occurs from the uppermost chamber.














Types of Volcanoes The most common volcanoes are the central type - this is a hill, mountain or hill with a depression at the top - a crater, from which magma comes to the surface. When a volcano erupts, rock fragments, ash, and erupted lava ejected from it remain on its slopes. The height of the mountain increases, and with it the crater moves higher and higher.


Another type of volcanoes is linear, or fissure. Their occurrence is associated with the rise of liquid basaltic magma along a crack in the earth's crust. Liquid lava spreads over vast areas, forming lava sheets. Such a volcano looks like a crack on the surface of the Earth.




From history In the 1st century, Italy experienced one of the most powerful eruptions of Mount Vesuvius in the history of mankind. Clouds of ash obscured the sun, streams of lava, mud and stones flooded the cities of Pompeii, Herculaneum and Stabia. The air was filled with toxic fumes. People tried to take refuge in houses and died there from suffocation or under collapsed roofs. The eruption of Vesuvius continued for two days, and when it finally stopped, the cities disappeared, completely buried under ash, stones, and dirt. Many centuries later, archaeologists dug them up and found them preserved under volcanic ash examples of ancient Roman architecture, sculptures, household utensils.



Location of volcanoes on Earth. There are about 500 volcanoes on Earth. The bulk are concentrated along the coasts and island arcs Pacific Ocean. Several volcanic islands are located in Indian Ocean, and in the Atlantic there are only 45 of them. In addition to the Pacific zone, there are still two areas of volcanism on Earth. One of them is in Africa, and the other includes the Mediterranean and Asia Minor, as well as eastern Turkey and Iran. On the territory of Russia, volcanic activity is observed in the areas of Kamchatka and the Kuril Islands.


Homework§ 2.4 pp. In writing: write in your notebook what are the harbingers of volcanic eruptions?

Ella Vassina
Presentation for students senior group on the theme "Volcano"

Target:

Introduce children to natural phenomena - volcano.

Tasks:

1- promote the development of cognitive activity in children, the desire for independent knowledge and reflection;

2- improve the ability to work with various materials, show a desire for transformation, and take a creative approach to solving assigned problems.

"I spit fire and lava,

I am a dangerous giant

I am famous for my bad fame,

What's my name?"

On a spaceship you can get into space, from where you can clearly see our planet. It is very huge and looks like a ball.

Deep below us, inside our planet, the earth is so hot it looks like mush.

There is water on our Earth (seas, rivers and oceans) and land (she's dry). We live on land. On land there is high mountains. Have you seen the mountains? The land is hard. But this is only from above, and deep inside the Earth it is so hot that even stones melt.

Word « VOLCANO» in Latin means "fire" And "flame". So named

one of the ancient Russian gods - the god of fire and blacksmithing.

Volcanoes there are eruptions

on the land…

There are also underwater...

"Sleepers" volcanoes differ little from other mountains.

But sometimes they "waking up", and then, the strong begins

underground roar, flames, ashes, red-hot

stones, volcanic bombs.

During an eruption volcano magma comes to the surface, it also

called LAVA.

The channel through which magma rises is called

MOUTH volcano.

Pieces of frozen lava - pumice. Look how interesting she is. There are air bubbles inside this pebble. This is because the lava boiled and seethed, and then froze.

Volcanoes seem beautiful, but they are very dangerous. After all, the fiery porridge is lava,

pouring out of the mountain, it can destroy cities where people live and start fires.

Scientists who monitor the condition volcanoes and can often predict the beginning of their eruptions called volcanologists.

Where fire flies from the mountain,

And it smokes from all sides,

There's a dangerous hooligan there

Awakened again (Volcano)

At that rather big mountain

The character is quiet for the time being.

But it could happen -

It will explode and smoke (Volcano)

The mountain woke up from its sleep,

It began to bubble and boil.

And it shot up from the cap

Lots of smoke, soot, ash.

The lava flows like honey, thick.

What do you call a mountain like this? (Volcano)

Publications on the topic:

Summary of direct educational activities in educational field“Artistic and aesthetic development” with children 5-6.


Technological map Task 1

I want to know


What is a volcano ?

  • Volcano- (from Latin vulcanus - fire, flame), a conical mountain, from the neck of which hot gases, steam, ash, rock fragments, as well as powerful streams of hot lava are emitted, which spread over the surface of the earth.
  • A volcano is a geological formation on the surface of the earth’s crust or the crust of another planet, where magma comes to the surface, forming lava, volcanic gases, and stones.
  • Volcanoes are conical mountains formed by the products of their eruptions.

Technological map Task 2.

Volcano is…………………………………………………………………………………...

…………………………………………………………………………………………………… ...

………………………………………………………………………………………………… .....



Structure of the volcano

  • A magma chamber is a place under the earth's crust,

where magma collects.

  • A volcanic vent is a channel through which magma rises.
  • A volcano crater is a bowl-shaped depression at the top of a mountain.
  • Lava is erupted magma.

Technological map Task 3 Complete the diagram "Structure of a volcano"



Eruption- this is the release of molten matter from the Earth’s crust and mantle to the surface of the planet, called magma .



Historical catastrophe of volcanic origin

K. Bryullov “The Last Day of Pompeii”





Causes of volcanic eruptions

Earthquake;

Pressure drop in the magma chamber. And with a sudden decrease in pressure, the magma melts, the gases expand and rush out.


Signs of a volcanic eruption

Almost always a volcanic eruption can be predicted. The most characteristic signs of the “awakening” of a volcano are:

  • - increased release of gases and

mineral waters on it

  • - temperature increase;
  • - underground hum.

Types of volcanic eruptions

If gases are released from the magma relatively calmly, then it flows to the surface, forming lava flows. This eruption was called effusive.


If gases are released quickly, the magmatic melt appears to instantly boil and burst with expanding gas bubbles.

Something powerful is happening.

explosive eruption

which received

Name explosive.


If the magma is very viscous and its temperature is low, then it is slowly squeezed out to the surface. Such an eruption is called extrusive.


Types of volcanoes

Most common central type volcanoes is a hill, mountain or hill with a depression at the top – crater , from which magma comes to the surface. thrown out during a volcanic eruption

rock fragments from it,

ash, poured lava

remain on its slopes.

The height of the mountain increases -

Xia, and with it the crater

moves higher and higher


Another type of volcano is linear or fissure . Their occurrence is associated with the rise of liquid basaltic magma along a crack in the earth's crust. Liquid lava spreads over vast areas, forming lava sheets. Such a volcano looks like a crack on the surface of the Earth.



Active volcanoes

Krakatoa

Fujiyama

Klyuchevskaya Sopka


Extinct volcanoes

Kilimanjaro




TEST

1. Geological formation that appears above channels and cracks in the earth’s crust, through which ash, lava, hot gases, water vapor, and rock fragments are erupted onto the earth’s surface

a) earthquake

b) seaquake

c) volcano

2. The word “volcano” comes from the name of the ancient Roman god:

A) underground kingdom

3.Find two reasons for a volcanic eruption

a) flood

b) earthquake

c) pressure drop in the magma chamber

d) tsunami

4. Find three signs of a volcanic eruption

a) increased release of gases and mineral waters;

b) increase in temperature;

c) underground hum.

d) decrease in temperature

5. Choose the wrong classification of volcanoes a) by shape b) by the amount of erupted lava c) by activity

d) by location

Answers to the test

3 - b, c

4 - a, b, c


Homework

Chapter 2, paragraph 5, tasks from the technological map Creative task:

(by choice and desire)

make a model of a volcano;

make a selection of facts about the volcanic eruption

Volcanologists and geomorphologists study the characteristics of volcanoes and the phenomena of volcanism.

Structure: hearth, vent, crater. A source is a place in the earth's crust or mantle. A vent is a channel through which magma rises. A crater is a hole, a funnel, a bowl at the top of a volcano mountain.

Volcanoes are classified by location, shape and activity.

By activity: extinct, dormant, active. This classification is quite arbitrary. The extinct ones have not erupted for more than 1000 years: they retain their general shape, the crater and slopes undergo changes. Sometimes they are active. Example: Mont Pelée in Martinique, Valley of Volcanoes in Buryatia, Kalara volcanoes.

Dormant volcanoes are volcanoes in which the probability of eruption is higher than that of extinct ones. Some of them are called supervolcanoes - Toba in Sumatra, Taulo in New Zealand, the volcanoes of Kamchatka.

Active ones are the main object of interest for volcanologists; they erupt frequently. They are located in the belts of young mountains, where mountain building continues. There is no consensus among scientists on how to accurately classify these geological formations. Most active volcanism: South and Central America, Hawaii, Japan, Sunda Islands.

They are classified by location: subglacial, terrestrial, underwater. The following types are distinguished by shape: dome, cinder cone, shield-shaped, stratovolcano, complex type.

Based on the general design, formations of central and linear types are distinguished. The first have a central channel through which lava comes to the surface. The second type is fissure, the channels through which the lava rises have an elongated shape. Scientists distinguish the area type, but no such type has been recorded on Earth, at least in our time. They are believed to have existed when the planet was forming.

The eruption is considered an emergency, a disaster. It can happen in an hour, a month, a year, several years. Consequences of the eruption: formation of caldera depressions, geysers, fumaroles. May occur low mountains, islands. Lakes form in craters.

Types of eruption: Hawaiian (basaltic lava comes to the surface, accompanied by smoky clouds, fiery avalanches), hydroexplosive (a lot of steam is released, confined to water bodies).

A mud-type volcano is a formation, as a result of whose activity mud and gases, rather than magma, come to the surface. Found in Russia and Central Asia.

The largest formations: San Pedro, Cotopaxi, Ojos del Salado in the Andes, Elbrus in the Caucasus, Fuji in Japan, Etna and Vesuvius in Italy, Klyuchevskaya Sopka in Kamchatka.

Recorded not only on Earth. If on other planets of the solar system and their satellites.