ERTH 2415 Lecture Notes - Lecture 15: Types Of Volcanic Eruptions, Geothermal Gradient, Landform
3 Dec 2015
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Takeaways: understand the mechanics of a volcanic eruption, understand the relation between magma composition, eruptive style, eruption type and volcanic landforms, be able to describe the different types of volcanic eruptions and landforms. Internal heat: volcanoes are a mechanism by which earth expels internal heat quickly, internal heat increases with depth. Called geothermal gradient: anomalously hot zones: Increase water content: phase change from solid to liquid accompanied by volume expansion. Volcanic eruption sudden occurrence of a violent discharge of volcanic. Volcanic eruption step by step: 1. Hot, solid rock from asthenosphere rises closer to the surface. Pressure decrease causes rocks to melt partially: decompression melting: 2. Volatiles gradually come out of the melt: 4. Powerful gas jet expels magma in the atmosphere. Eruptive style: 2 eruptive styles: peaceful vs explosive, relation between: tectonic environment, magma composition, eruptive. Caution: a volcano can change eruption type through time: relation between: eruptive style, eruption type, magma composition,
