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| is the main source of magma. |
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| Difference b/w lava and magma |
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Definition
| Magma is molten rock below Earth's surface and lava is magma after it erupts. |
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| A hill or mountain contructed from the accumulation of lava and other erupted materials. |
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| Magma periodically empties to the surface through a pipelike conduit in repeated cycles. |
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| Lava that can erupt from vertical cracks (fissures) and other vents on the flanks of a volcano. |
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| a lava in mafic composition that has a low silica content, erupts at high temperatures, and flows readily. mostly gentle eruptions. |
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| A lava in intermediate composition that has a higher silica, erupts at lower temperatures, and is more viscous. Eruptions along many subduction zones. |
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Definition
| The lava in felsic composition that is richest in silica, making it the stickiest and least fluid kind of lava. It erupts in temperatures of only 600-800 degree Celsius. |
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| Gas cavities created by when pressure is released, water vaporand other dissolved gases escaping from lava. |
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Definition
| Fragmentary volcanic rocks ejected into the air. |
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Term
| Central Eruptions: What are Shield Volcanoes? |
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Definition
| They are built up by the accumulation of thousands of thin basaltic flows that spread as gently sloping sheets. |
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| CE: What are Cinder-Cone Volcanoes? |
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Definition
| They are formed when ejected material is deposited as layers that dip away from the crater at the summit. |
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| CE: What are Stratovolcanoes? |
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Definition
| are built from alternating layers of pyroclastic material and lava flows. |
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Definition
| They are a bowl-shaped pit, that is found at the summit of most volcanoes, centered on the vent. |
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Definition
| A large, steep-walled, basin-shaped depression formed after a violent eruptions in which large volumes of magma are discharged, when the overlying volcanic structure collapses catastrophically through the roof of the emptied magma chamber. |
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| Fissure eruptions: What are flood basalts? |
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Definition
| Successive flows often pile up into immense basaltic lava plateaus. |
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| FE: What are ash-flow deposits? |
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Definition
| Fissure eruptions of pyroclastic materials on continents have produced extensive sheets of hard volcanic tuffs. |
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Definition
| A geyser is a vent in Earth's surface that periodically ejects a column of hot water and steam. |
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| How can volcanism cause global cooling? |
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Definition
| The sulfuric gases from volcanism form an aersol that blocks enough of the Sun's radiation from reaching Earth's surface to lower global temperatures. |
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Definition
| A narrow, cylindrical jet of hot, solid material rising from deep within the mantle and though to be responsible for intraplate volcanism. |
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Definition
| A volcanic center found at the beginning of progressively older aseismic ridges or within a continent far from a plate boundary. |
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| What is a large igneous province? |
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Definition
| They are large volumes of predominatly mafic extrusive and intrusive rocks whose origins lie in processes other than normal seafloor spreading. |
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