how volcanoes erupt step by step?
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Volcanoes erupt when molten rock called magma rises to the surface. Magma is formed when the earth's mantle melts. 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.
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There are two predominant types of volcanic eruptions: Effusive eruptions – magma rises through the surface and flows out of the volcano as a viscous liquid called lava. Explosive eruptions – magma is torn apart as it rises and reaches the surface in pieces known as pyroclasts.
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Definition: A volcanic eruption occurs when magma is released from a volcano. Volcanic eruptions can be quite calm and effusive, or they can be explosive. Effusive eruptions produce lava flows, while explosive eruptions produce ash and pyroclastic density currents. Volcanic Eruption.
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All volcanic eruptions start the same, with molten rock (magma) rising up through the Earth and breaking through the Earth's crust. However, this is where the similarities end. The different types of volcano erupt differently.
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Volcanoes happen when magma rises to the surface of the earth, which causes bubbles of gas to appear in it. This gas can cause pressure to build up in the mountain, and it eventually explodes. When the magma bursts out of the earth, it is called lava.
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Volcano eruptions go through several stages typically beginning with earthquake swarms and gas emissions, then moving to initial steam and ash venting, lava dome buildup, dome collapse, magmatic explosions, more dome growth interspersed with dome failures and finally, ash, lava and pyroclastic eruptions.
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The entire region is known as a subduction zone. Subduction zones have a lot of intense earthquakes and volcanic eruptions. The subducting plate causes melting in the mantle above the plate. The magma rises and erupts, creating volcanoes.
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A volcano results from collection of lava after several volcanic eruptions. Hot magma flows through a vent and cools upon reaching the surface of the earth. A volcanic mountain is made up of lava and piles of rocks.
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Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust. All magma develops underground, in the lower crust or upper mantle, because of the intense heat there.
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Tectonic plates also move away from one another to produce volcanoes. Hot magma rises from the mantle at mid-ocean ridges pushing the plates apart. Volcanoes such as Eyjafjallajökull, Iceland, occur along the fractures that appear as the plates move apart.
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The subducting oceanic plate melts as it reenters the mantle. The magma rises and erupts. This creates a volcanic mountain range near the coast of the continent. This range is called a continental arc.
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The eruptions of Iceland's volcano Eyjafjallajökull in 2010 were apparently triggered by a chain reaction of expanding magma chambers that descended into the Earth, a group of researchers now says. ... Intriguingly, the researchers found that microearthquakes apparently occurred at greater depths with each outburst.
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['Magma comes out of the rift valley.', 'Magma cools to rock and hardens.', 'Rock is pushed away as new rock is formed at MOR.', 'Oceanic crust and continental crust meet at the trench.', 'Oceanic crust bends down under the continental crust.', 'Gravity pulls rock towards mantle.', 'Rock melts to mantle.']
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When Volcanic material erupts and cools and crystallizes on Earth's surface, it forms igneous rock. Rock that forms when lava cools too quickly to form crystals, such as obsidian. ... When magma cools slowly, large well-defined crystals form. The arrangement of minerals in intrusive rocks are random.
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As volcanoes erupt, they build up layers of lava that may eventually break the water's surface. When the tops of the volcanoes appear above the water, an island is formed. While the volcano is still beneath the ocean surface, it is called a seamount.
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Cinder cones are the simplest type of volcano. They are built from particles and blobs of congealed lava ejected from a single vent. As the gas-charged lava is blown violently into the air, it breaks into small fragments that solidify and fall as cinders around the vent to form a circular or oval cone.
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Subduction Zone Volcanism Most explosive eruptions occur in volcanoes above subduction zones, where one tectonic plate dives beneath the other. Eighty to 120 kilometers below the surface, magma forms when the rocks of the mantle melt just above the subducting plate.