Volcanoes - • magma chambers below the surface are sites...

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Volcanoes 17/04/2008 15:34:00 Scoria A vesicular, usually lapilli to block size rock that is ejected out usually out of  cinder cones during strombolian eruptions *characteristics of cinder(scoria) cones cones made up mostly of scoria(quenched melt with bubbles? From by relatively low energy eruptions driven by gas expansion in high  viscosity silicate melt (strombolian eruptions) Often occur on flanks of larger volcanoes Cones are typically only several hundreds of meters high *calderas calderas are collapsed craters they form when magma empties out of a magma chamber during an  exceptionally explosive eruption, creating a void below the volcano mount mazama(crater lake) st francois mtn, MO….calderas *magma chambers-hey to understanding explosive eruptions
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Unformatted text preview: • magma chambers below the surface are sites of temporary lava storage • magma chambers can be several kilometers below volcanoes *cascadia subduction and the cascades • x-section across cascadia subduction zone ← *distribution of seismicity under MSH-past decade ← *making bubbles in magmas • decompression of magma during ascent through magma conduits • crystallization of magma in a chamber ← *decompression of magma in conduits • magma chambers become periodically replenishes by intrusion of new magma • the new magma forces magma rise up the conduit where it becomes saturated in water and bubbles form, causing a violent eruption 17/04/2008 15:34:00 ← 17/04/2008 15:34:00 ←...
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This note was uploaded on 05/06/2008 for the course GEO 1400 taught by Professor Peternabelek during the Winter '08 term at Missouri (Mizzou).

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Volcanoes - • magma chambers below the surface are sites...

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