A truly amazing sight is the volcanic eruption. But what is a volcano like? How does a volcanic eruption take place? Why do some of them spew huge flows of lava at different intervals, while others sleep peacefully for centuries?
What is a volcano?
Outwardly, the volcano resembles a mountain. There is a geological fault inside it. In science, a volcano is usually called a formation from a geological rock located on the surface of the earth. Through it, magma erupts outward, which is very hot. It is magma that subsequently forms volcanic gases and rocks, as well as lava. Most of the volcanoes on earth were formed several centuries ago. Today, new volcanoes appear on the planet occasionally. But this happens much less often than before.
How do volcanoes form?
If we briefly explain the essence of the formation of a volcano, it will look like this. Under the earth's crust there is a special layer under strong pressure, consisting of molten rocks, and it is called magma. If cracks suddenly begin to appear in the earth's crust, then hills are formed on the surface of the earth. It is through them that magma comes out under strong pressure. On the surface of the earth, it begins to disintegrate into hot lava, which then solidifies, causing the volcanic mountain to become larger and larger. The emerging volcano becomes so vulnerable on the surface that it spews volcanic gases with high frequency to the surface.
What is a volcano made of?
In order to understand how magma erupts, you need to know what a volcano is made of. Its main components are: a volcanic chamber, a vent and craters. What is a volcanic hearth? This is where magma is formed. But not everyone knows what a volcano's mouth and crater are? A vent is a special channel that unites the hearth with the surface of the earth. A crater is a small bowl-shaped depression on the surface of a volcano. Its size can reach several kilometers.
What is a volcanic eruption?
Magma is constantly under strong pressure. Therefore, there is a cloud of gases above it at any time. Gradually, they push the red-hot magma to the surface of the earth through the mouth of the volcano. This is what causes the eruption. However, one small description of the eruption process is not enough. To see this spectacle, you can use the video, which you need to watch after you have learned what the volcano consists of. Likewise, on the video you can find out which volcanoes do not exist at the present time and how the volcanoes that are active today look like.
Why are volcanoes dangerous?
Active volcanoes are dangerous for a number of reasons. The dormant volcano itself is very dangerous. He can "wake up" at any time and begin to spew lava flows spreading over many kilometers. Therefore, you should not settle near such volcanoes. If an erupting volcano is located on the island, a dangerous phenomenon such as a tsunami may occur.
Despite their danger, volcanoes can serve humanity well.
Why are volcanoes useful?
- During the eruption, a large number of metals appear that can be used in industry.
- The volcano gives rise to the strongest rocks that can be used for construction.
- The pumice stone from the eruption is used for industrial purposes, as well as in the production of rubber bands and toothpaste.
In ancient Rome, the name Vulcan was borne by a mighty god, the patron saint of fire and blacksmith's craft. We call volcanoes geological formations on the surface of the land or on the ocean floor, through which lava comes out of the deep bowels of the earth to the surface.
Often accompanied by earthquakes and tsunamis, large volcanic eruptions have had a significant impact on human history.
Geographical object. The value of volcanoes
During a volcanic eruption, magma comes to the surface through cracks in the earth's crust, forming lava, volcanic gases, ash, volcanic rocks and pyroclastic flows. Despite the danger these powerful natural objects pose to humans, it is thanks to the research of magma, lava and other products of volcanic activity that we managed to gain knowledge about the structure, composition and properties of the lithosphere.
It is believed that thanks to volcanic eruptions, protein life forms could appear on our planet: the eruptions released carbon dioxide and other gases necessary for the formation of the atmosphere. And volcanic ash, settling, became an excellent fertilizer for plants due to the potassium, magnesium and phosphorus contained in it.
The role of volcanoes in the regulation of the Earth's climate is invaluable: during an eruption our planet “releases steam” and cools down, which largely saves us from the consequences of global warming.
Characteristics of volcanoes
Volcanoes differ from other mountains not only in composition, but also in strict external outlines. From the craters at the top of the volcanoes, deep, narrow ravines, formed by streams of water, stretch down. There are also entire volcanic mountains formed by several nearby volcanoes and the products of their eruptions.
However, a volcano is not always a mountain breathing fire and heat. Even active volcanoes can look like straight-line cracks on the planet's surface. There are especially many such "flat" volcanoes in Iceland (the most famous of them, Eldgya, is 30 km long).
Types of volcanoes
Depending on the degree of volcanic activity, there are: acting, conditionally active and extinct ("sleeping") volcanoes. The division of volcanoes by activity is rather arbitrary. There are cases when volcanoes, considered extinct, began to show seismic activity and even erupt.
Depending on the shape of the volcanoes, there are:
- Stratovolcanoes- classic "mountains of fire" or volcanoes of the central type, cone-shaped with a crater at the top.
- Volcanic crevices or cracks- faults in the earth's crust, through which lava emerges to the surface.
- Calderas- depressions, volcanic cauldrons, formed as a result of the failure of a volcanic summit.
- Shield- so called because of the high fluidity of the lava, which, flowing for many kilometers in wide streams, forms a kind of shield.
- Lava domes - formed by the accumulation of viscous lava above the vent.
- Slag or tephra cones- have the shape of a truncated cone, consist of loose materials (ash, volcanic stones, boulders, etc.).
- Complex volcanoes.
In addition to terrestrial lava volcanoes, there are underwater and mud(they spew out liquid mud, not magma) Submarine volcanoes are more active than terrestrial ones, through them 75% of the lava erupting from the Earth's bowels is emitted.
Types of volcanic eruptions
There are 4 main types of volcanic eruptions, depending on the viscosity of lavas, composition and amount of eruption products.
Effusive or Hawaiian type- a relatively calm eruption of lava formed in craters. The gases escaping during the eruption form lava fountains of drops, threads and lumps of liquid lava.
Extrusion or dome type- accompanied by the release of gases in large quantities, leading to explosions and the release of black clouds from ash and lava fragments.
Mixed or Strombolian type- abundant lava outflow, accompanied by small explosions with the release of pieces of slag and volcanic bombs.
Hydroexplastic type- typical for underwater volcanoes in shallow water, accompanied by a large amount of steam released during the contact of magma with water.
The largest volcanoes in the world
The highest volcano in the world Ojos del Salado located on the border of Chile with Argentina. Its height is 6891 m, the volcano is considered extinct. Among the active "mountains of fire" the highest is Llullaillaco- volcano of the Chilean-Argentine Andes with a height of 6,723 m.
The largest (among terrestrial) in terms of area is the volcano Mauna loa on the island of Hawaii (height - 4,169 m, volume - 75,000 km 3). Mauna loa also one of the most powerful and active volcanoes in the world: since its "awakening" in 1843, the volcano has erupted 33 times. The largest volcano on the planet is a huge volcanic massif Tamu(area 260,000 km 2), located at the bottom of the Pacific Ocean.
But the most powerful eruption in the entire historical period was produced by a "low" Krakatoa(813 m) in 1883 in the Malay Archipelago in Indonesia. Vesuvius(1281) - one of the most dangerous volcanoes in the world, the only active volcano in continental Europe - located in the south of Italy near Naples. Exactly Vesuvius destroyed Pompeii in 79.
In Africa, the highest volcano is Kilimanjaro (5895), and in Russia - a two-peaked stratovolcano Elbrus(North Caucasus) (5642 m - western peak, 5621 m - eastern).
There are boring and gray days when the little one does not know what to do and wanders around the house. Or running around with heartbreaking screams, trying to get attention. And adults, as always, instantly find a lot of important, in their opinion, work.
Stop! Moms and dads, grandparents, put aside your urgent matters (unless, of course, you were flooded by the neighbors upstairs and the pie in the oven is not burning) and do a little miracle for your child. It's very simple - show him active model of the volcano.
No, we do not need matches and fire, and there is no need to urgently look for gas masks either. Everything you need can be found in the kitchen and on the shelf in the nursery.
So we do an active model of the volcano.
1. Preliminary conversation.
Depending on the age of the child, compose a story about a volcano.
A volcano is a mountain that has a hole (crater) at the top that leads into the depths of the Earth. Our Earth consists of the upper solid layer, the middle - liquid and hot, inner - the core.
For a better understanding, you can show an ordinary chicken egg. The shell is the first layer, the protein is the liquid layer, the yolk is the core. Dig a hole in the egg shell - it will be a volcano crater, shake the egg a little, and the child will see that a protein appears through the hole (even if this is not entirely scientific, because magma is escaping through the crater of the volcano - a mixture of the second layer of the Earth - the mantle and part of the lithosphere - solid layer, but the very essence of the process will be clear).
So with a volcano, magma escapes from the crater due to the generated gas (shake the bottle with mineral sparkling water and open the cap). Sometimes magma flies out in a pillar, and sometimes it calmly pours out to the surface. Solidified lava is a well-known pumice stone.
The tale of the river and volcano
Alexey Bormashov
Lived in one of the distant countries
Old grandfather volcano.
He smoked a pipe all day.
Black smoke poured into the sky.Nearby the river was flowing.
A green forest grew behind her,
Ate, pine trees to heaven,
Many animals lived in it.The river went round the mountain,
Where the volcano in the cave lived
And she said to him:
“You have smoked the whole sky!Why smoke uselessly ?,
So it won't take long to get sick. "
But the volcano didn't answer
He sprinkled ash on the river.One morning a noise rang out
A fire rose over the mountain,
Everything around trembled
And the volcano exploded suddenly.Lava flowed like a river
Burning everything behind you.
Then the trees cried out:
“What are we to do, we are lost ?!Evil fire will destroy everyone.
Who will save us, who will help,
Where to look for protection
And who should I call for help? "Everyone began to ask for the river
Put out the lava flame.
The river in the forest answered:
“I warned the volcano,
That he would quit smoking
The old man needs to be treated.
I will fill the lava with water
And I will stop the fire. "Lava approached the river,
That wave rose up
And rushed to the lava,
And then the fight began.Steam rose over the mountain
The thick fog covered everything
Rumble, crackle, the water boils,
Lava hisses like a snake.Soon I began to get tired
And retreat up the mountain.
The river won the battle
The lava flame extinguished.The forest thanks her
Joyfully the foliage rustles.
Stopped smoking volcano
And he sleeps peacefully in the cave.If someone does not know yet,
All the Ministry of Health warns:
"Smoking is great harm!"
Be healthy, my reader.
2. Making a model of an active volcano.
We sculpt a hollow volcano from plasticine in the form of a cone with a wide base and a narrower top with a hole.
3.The volcano in action.
Pour baking soda on a flat surface. We put ours on top volcano... We press the base tightly to the surface.
Is the volcano ready? Are the audience ready?
Pour vinegar into the crater of the volcano (either from a bottle or from a spoon) in a thin stream and observe a real eruption. We repeat.
Full picture video:
Interesting? A fascinating sight and a lot of positive emotions (and some 2 liters of vinegar for half a pack of soda, since children will want to do the volcanic eruption repeatedly).
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You can watch how the volcano erupts at home not only on TV. With the help of a small chemical experiment, you will make a real eruption on a fabulous island.
In this article, you will learn
Everything that's needed
For the experience, you will need a little household chemicals and decorative elements to create an island. A volcano island can be made from natural materials, or you can use dinosaur sensor box kits.
The model of the volcano is molded from plasticine. Creating a fabulous volcanic island for the experience is central to the development of a child's imagination and creativity. Such classes will help instill a love of chemistry and geography. The child will develop fine motor skills of the fingers during the manufacture of plasticine terrain and its inhabitants.
To make an island you need:
- cardboard;
- stapler or narrow tape;
- box with colored plasticine;
- small animal toys;
- multi-colored pebbles;
- a large plastic box or bowl in which the island will stand;
- glass or plastic container with a volume of 200 ml for the vent of the volcano.
For the experiment you will need:
- soda 20 g;
- food coloring:
- vinegar 9%;
- dish detergent 25 ml;
- water 100 ml.
Usually, the experience takes place until Mom runs out of all the soda and all the vinegar, so please be patient.
Children cannot conduct the experiment independently without adults. If vinegar gets into the eyes or mouth of a child, it may burn the mucous membranes, and if swallowed, it will burn the esophagus.
Making a fabulous island
You can build an island in a large plastic container. Pour in real water, line the bottom with round pebbles. Make a container for a volcano from a jar for baby food or an old glass. For the mountain, inside which the container will stand, you need to make a cardboard model, his child will gladly coat it with plasticine.
The sequence for making a volcanic mountain:
- a circle of the required diameter is cut out of thick cardboard;
- make an incision from the edge to the center of the circle;
- fold the cone;
- the edges of the cone are fastened with a stapler or tape;
- the upper part of the cone is cut off at a height equal to the container selected for the volcano;
- place the container inside the cone.
I cover the mountain with plasticine on top. To do this, roll out small brown plasticine cakes and stick to a paper cone, completely covering the cardboard. The top of the volcano can be made of red plasticine, which will simulate hot lava.
Set the volcanic mountain on a dry pebble island. They are seated around small rubber animals that are among children's toys. Multi-colored amazing dinosaurs or wolves, foxes, bunnies, bears and other inhabitants of the forest and jungle. Depending on which animals were planted, vegetation is selected for the island. Large tree ferns and horsetails for dinosaurs, and ordinary Christmas trees and birches for bunnies and foxes.
Plastic plants are also often sold in children's play sets. You can use a leaf of a live fern and twigs of plants if it's summer outside. Plants can also be molded from plasticine, made from threads and beads, or ordinary cardboard.
You can make small houses out of cardboard, for plastic Indians and toy soldiers. It is better to use cardboard for making plants and houses when the island is in a container with blue colored sand instead of water or on a blue plasticine sea.
Carrying out an experiment
Finally the island is ready. All toy animals and people froze in anticipation of an interesting event - a volcanic eruption. They know that the volcano is not real and therefore are not afraid of it.
For the experiment, a tablespoon of soda is poured into a jar-mouth of the volcano. Add a tablespoon of dish detergent. Red or orange food coloring is dissolved in 100 milligrams of water and poured into baking soda and detergent. The basis for the experiment is ready, it remains to add vinegar. Mom, you can let the child pour vinegar into the volcano on their own, under her supervision, so that he does not do it in her absence. It is better to repeat the experiment for an encore, pouring vinegar into the "mouth" of the volcano and pouring soda there, while the child is interested and asks to repeat the experiment.
When the vinegar is added, the soda will begin to foam, erupting from the "volcanic vent" like red or orange lava. The detergent will allow the "lava" to foam longer and more profusely, overflowing from the vent and flooding the surroundings along with plants and animals that are inadvertently placed too close.
Afterword
The volcano experience for young children is safest with baking soda and vinegar. It can be repeated many times, and it will not be difficult to get the necessary materials for the experiment.
The most interesting thing in the experience is the creation of a fairytale island with a child, which can be used not only for the chemical experiment "Volcano", but also for an exciting game.
With older children, you can conduct the "Volcano" experiment at home using 
, potassium permanganate and glycerin. For the experiment, ammonium dichromate is poured into an evaporation bowl in the form of a slide, in the middle of which a depression is made. A little potassium permanganate and a few drops of glycerin are added to the well.
After a few minutes, due to the interaction of potassium permanganate and glycerin, the ammonium dichromate will ignite. Sparks will be sprinkled from the volcano in all directions, and a fountain of fire will begin to erupt. Before starting the experiment, the bowl must be placed on foil so as not to burn the surface on which the experiment will take place.
Ammonium dichromate can simply be ignited and it will burn like a volcano, emitting sparks. The experience is exciting, but without the presence of adults, it is better not for children to be allowed to do it. Not only sparks can cause burns, but also the chemicals used.
Good luck with your experiments!
Volcanoes are one of the most amazing and mysterious geological formations on Earth. However, many of us have only a superficial understanding of them. What is the nature of volcanism? Where and how is the volcano formed?
How is a volcanic eruption formed?
How and why the process is hidden in the bowels of the Earth. During the accumulation of magma, a large amount of thermal energy is generated. The temperature of the magma is high enough, but it is not able to melt because the crust presses on it from above. If the layers of the earth's crust press on the magma weaker, the hot magma becomes liquid. It gradually becomes saturated with gases, melts rocks on its way and in this way stretches its way to the surface of the earth.
If the volcanic vent is already filled with solidified and solidified lava, then the eruption will not occur until the magnitude of the magma pressure is sufficient to push out this plug. always accompanied by an earthquake. Ashes can be thrown up to a height of several tens of kilometers.
Volcanoes are formations resembling mountains, from which hot magma erupts. How is a volcano formed? In the presence of cracks in the earth's crust, hot magma erupts to its surface under pressure. The slopes of the volcano are formed as a result of the subsidence of rocks, lava, ash near the vent.