The surface of the earth the crust is comprised with number of tectonic plates which are constantly moving slowly. most of the volcanic activity occurs at the places where these plates meets. the plate boundaries. The large layer of rock beneath Earth's crust called the Mantle which is mostly solid. But in certain places it cannot and become magma.
Melting may happen where tectonic plates are pulling apart or where one plate is pushed down under another . Magma is lighter than rock so rises towards the Earth's surface . As the magma rises , bubbles of gas form inside it . Runny magma erupts through openings or vents in the earth's crust before flowing onto its surface as lava . If magma is thick , gas bubbles cannot easily escape and pressure builds up as the magma rises . When the pressure is too much an explosive eruption can happen , which can be dangerous and destructive . Another way an eruption happens is when water underneath the surface interacts with hot magma and creates steam , this can build up enough pressure to cause an explosion .
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The surface of the earth the crust is comprised with number of tectonic plates which are constantly moving slowly. most of the volcanic activity occurs at the places where these plates meets. the plate boundaries. The large layer of rock beneath Earth's crust called the Mantle which is mostly solid. But in certain places it cannot and become magma.
Melting may happen where tectonic plates are pulling apart or where one plate is pushed down under another . Magma is lighter than rock so rises towards the Earth's surface . As the magma rises , bubbles of gas form inside it . Runny magma erupts through openings or vents in the earth's crust before flowing onto its surface as lava . If magma is thick , gas bubbles cannot easily escape and pressure builds up as the magma rises . When the pressure is too much an explosive eruption can happen , which can be dangerous and destructive . Another way an eruption happens is when water underneath the surface interacts with hot magma and creates steam , this can build up enough pressure to cause an explosion .