How volcanic eruptions are formed, how volcanic eruptions are formed

A volcano is not a mountain that spews out "fire", it spews out a high-temperature, viscous substance called magma. When the volcano erupts, the scene is spectacular. Normally, magma is wrapped in the earth's crust, and because of its extremely high temperature and the tremendous pressure of the earth's crust, the magma rushes out of the ground violently when it encounters a thin place or a crack in the earth's crust.

When the volcano erupted, accompanied by an earth-shattering roar, the stones flew and rolled, and the blazing magma gushed out from the ground like an incomparable fire dragon, devouring everything around, and in an instant, dozens of miles were shrouded in a thick smoke and fog. Sometimes, volcanic eruptions can cause a high mountain to rise in an instant, as was the case with Mount Kilimanjaro and Mount Cotoppakshi near the equator; Sometimes, it can swallow entire villages and towns in an instant. Volcanoes are formed beneath the surface, and the deeper they go, the hotter they get, about 20 miles deeper, and hot enough to melt most of the rock.

When the rock melts, it expands and requires more and more space. The material melted by the high temperature then rises along the cracks caused by the uplift. When the pressure in the lava trough is greater than the pressure of the rock above it, it erupts outwards to form a volcano.

A volcanic eruption is the release of ejecta such as magma from a crater to the surface in a short period of time. Due to the large amount of volatiles contained in the magma, coupled with the confining pressure of the overlying rock layer, these volatiles are dissolved in the magma and cannot overflow, when the magma rises close to the surface, the pressure decreases, and the volatiles are released sharply, thus forming a volcanic eruption. Volcanic eruptions are a peculiar geological phenomenon, a manifestation of the movement of the earth's crust and one of the most intense displays of thermal energy on the surface of the earth's interior.

The Earth's interior temperature and density are uneven, forming mantle convection or mantle plumes inside the mantle. Under the action of external forces, molten matter comes together and forms a magma sac in the shallow part of the earth. When the pressure of the magma sac is greater than the pressure of the formation, the magma breaks through the earth's crust along the fault or weak point.

Plate interactions: In the subduction or collision zone of the plates, magma pockets can also form due to the formation of local high temperatures due to friction, which can trigger volcanic activity. <

1. The temperature and density of the earth's interior are uneven, forming mantle convection or mantle plumes inside the mantle. When a hot substance rises to the shallow part of the earth, partial melting occurs due to a decrease in pressure.

2. Under the action of external forces, these molten materials come together and form magma sacs in the shallow part of the earth. When the pressure of the magma sac is greater than the pressure of the formation, the magma breaks through the earth's crust along the fault or weak point, causing a volcanic eruption.

3. There is also a kind of volcanic cause due to plate interaction, such as in the subduction zone or collision zone of the plate, due to the friction to form a local high temperature, the dehydration of some water-bearing minerals also reduces the melting point of the rock, at this time it will also form a magma sac, thus triggering volcanic activity.

Crustal movement is the cause of volcanic eruptions, and the upper part of the Earth's interior upper mantle is filled with hot magma. Under extreme pressure, magma can break through the earth's crust from weak spots along the volcanic channels and throats, causing volcanic eruptions. After the eruption of the volcano, it will change the surrounding terrain to form volcanic rocks Xiaoshan, volcanic islands, and crater lakes, etc., the most famous in our country is Changbai Mountain Tianchi, in fact, it is also a crater lake.

The theory of plates is the doctrine of calamity to the country and the people.

In chemical experiments, chemical changes occur in substances, heat and kinetic energy appear, chemical changes occur in the interior of the earth, and chemical changes in the interior of the earth form huge heat and kinetic energy, resulting in volcanic eruptions. This is the most scientific answer.

Why do volcanic eruptions?

It turns out that the temperature of the magma in the interior of the earth is very high, and the temperature near the center is as high as 4000. It can flow like molten iron in steelmaking. As the temperature of the Earth's interior rises, these gas-rich magma are like boiling gruel, which is always trying to spray out.

If we compare the earth's crust to a "pot lid", the pressure on the earth's crust is very high, and it is not so easy for magma to lift this "pot lid" and rush out. Therefore, on the one hand, magma should gather energy, and on the other hand, it is necessary to choose places where the earth's crust is relatively weak and there are cracks in the earth's crust as a gap to rush out.

With the precipitation of gas in the magma, the internal pressure continues to increase, and the activity continues to intensify, and when the gas pressure reaches a certain limit, the magma will break through the "cover" and rush to the sky. Rushing to the ground like a fiery snake, the heavens and the earth seem to have returned to the period of flooding, which is the occurrence of a volcanic eruption.

Volcanic eruptions need to go through three stages, which are the initial magma formation and ascent phase, the magma sac stage and the stage of leaving the magma sac to the surface, all three of which are through the accumulation of momentum to form the final magnificent eruption.

1.Magma formation and initial ascent phase:

In fact, magma is not achieved overnight, it requires a process of formation: partial melting and separation of the molten body from the parent rock. It is unlikely that the two processes will be mutually established, and the separation of the melt from the parent rock generally occurs at the beginning of the melting.

Moreover, partial melting is usually a state of coexistence between liquid and solid, and partial melting can occur with the increase of temperature, pressure and solidus. When the molten material rises slowly with the flow of the earth's mantle, the resulting liquid and solid will become separated.

2.Magma Sac Stage:

The magma sac is an important area where magma is stored, and it is also the area where magma is more concentrated in the crust or upper mantle rock medium, and it is a high-temperature fluid similar to the oil reservoir facies, and generally speaking, the magma in the mantle column accounts for only about 1 3 of the total. From a more local position, it can be seen as a collection of liquids with relative internal circulation.

3.From the magma sac to the surface stage:

The rise of magma from the magma source area to the near-surface pathway is actually related to the excess pressure of the magma sac, the formation and penetration of the channel, and the crystallization of the magma rise to a certain extent with the process of degassing. When the tensile-shear stress in the crust is greater than the fracture strength of the local rock, there is a chance to form a certain tensile property, and if the fractures are connected, the magma eruption will pass through the connected fractures.