Earth Sciences 1022A/B Lecture Notes - Lecture 4: Divergent Boundary, Magma Chamber, Asthenosphere
7 Dec 2015
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Document Summary
Earth sciences 1022a lecture 4 volcanoes. Gas pressure builds up, magma and gas rise up through openings they can find in the crust and it erupts through a volcano. When the eruptions happen, lava goes on the sides of the volcanoes. The top of the volcano could be blown right off (violent) It determines on the composition of the magma. Cooler, viscous aa (blocky type of look)- very sharp edges, blocky looking. Pillow lavas form under water - when the lava flows in the water off of the land, as soon as it hits water, the outer skin is instantly quenched. Inside of the glassy surrounding, its still flowing inside. Pyroclastic material ranges from fine ash to large bombs - go down the side of the volcano. Nu e ardentes - very hot cloud of ash and gas. Lahars - volcanic eruption happens under snow/glacier, lots of water and snow mixed up with the pyroclastic debris o o o.
