GEOL 1250 Lecture Notes - Lecture 7: Hawaiian Islands, Magma Chamber, Plinian Eruption
28 May 2016
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Document Summary
Largest shield volcano - olympus on mars. Mars doesn"t have plate tectonics has less gravity. Fracture between continents are opened and basalt oozes out for as long as it takes each direction to be covered by basalt. Has not happened in 11 million yr. Biggest continental flood basalt: siberian flood (260 million years ago) Some people claim that it is the reason of extinction. Brings gas to the atmosphere = climate change. Plinian column - gas/ash is spread out by the wind forming tuffs. Pyroclastic surges / ash flows - plinian column collapses or volcano moves sideways (super sonic) Fluid with no viscosity, very hot ash with hot gas = low viscosity - moves fast. Sometimes will erupt as lava flow (more viscous = steeper slope) or pyroclastic (not as large viscosity is slower) Blast determined by volume of material that is eruption. Hole in the ground with a magma reservoir.
