How are volcanoes formed?

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โˆ™ 2017-06-18 01:18:39

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Volcanoes are formed by upwelling of magma (hot molten rock) deep under the earth's surface.

No one is quite sure why magma rises in certain areas, but when it does, it forms pockets which create pressure on the rock of the Earth's crust. When the pressure inside these pockets becomes sufficiently large, the magma forces itself through the crust to the surface of the earth and spills out as lava. If the crust above the magma pocket is relatively weak or has re-established channels for the magma to flow through, the magma will erupt relatively gently and form shield volcanoes (such as the Mauna Loa volcano in Hawaii or the undersea volcanoes on the Atlantic Rift). When the crust is relatively solid, however, lava may force its way up for a while, building a pyramidal volcano around its main channel, but this channel will eventually become blocked by solidified lava, and pressure will build to a much greater level, creating more violent eruptions when it releases (as happened with Mount St Helen's and Krakatoa).

magma finds its away up (under pressure) from the earths mantle of liquid magma through channels this magma then builds to a pressure which the overlying rock cannot contain any more and then a volcanic erruption takes place. These erruptions then build up gradually over thousands of years little by little and eventually a volcano is 'born' and 'grows'. This is a simplified version of how certain types of volcano form, there are many different was volcanos can form. There are shield, cinder cone ect, so someone else (with more time) can elaborate on this, but this should be enough for you to understand it properly.
When a small and a big tectonic plates presses against one another, the force of the bigger one pushes over the small one leaving a gap. Magma from the Earth's core can escape through this opening, turning into lava when it reaches the earth's surface.
A volcano is formed when one tectonic plate slides under another tectonic plate. The plate underneath is heated and melts and resulting pressure pushes it to the surface as a volcano.
A volcano is an opening, or rupture, in a planet's surface or crust, which allows hot magma, volcanic ash and gases to escape from below the surface .
Volcanoes are formed when magma from within the Earth's upper mantle works its way to the surface. At the surface, it erupts to form lava flows and ash deposits. Over time as the volcano continues to erupt, it will get bigger and bigger.
Volcanoes are formed from the failures in the outer covering of the earth's crust which has cracks and imperfections. These allow the hot high-pressure inside liquids to escape as lava and burning gases. This hot material is the result of radio-active elements deep inside the earth which decay and in so doing generate heat. The same material is present in the sun, but unlike the earth this material is exposed on the outside without any crust being present. The smaller size of the earth has allowed greater cooling to occur here.
A volcano is made when the tectonic plates beneigh the earths crust move about. This isn't an instant process though, it takes thousands of years. A slightly submerged plate will slowly melt forming magma (lava that hasn't yet reached the surface), the magma will build up eventually reaching the surface and forming a volcano. The volcano will form layers from lava during an eruption.
Volcanoesare formed when two plates collied and pressure builds up, then the oceanic plate gets subducted below the Continental plate which then melts and causes magma to rise up creating a volcano :)
a volcano starts off as a piece of ground, and over time as it keeps erupting, that it becomes larger because it lava cools and turn into rock, soon it forms a volcanoes.
Volcanoes are made due to the collision of two continental plates during earthquakes.

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