GEOL 1030 Lecture Notes - Lecture 6: Rhyolite, Andesite, Viscosity
Document Summary
What determines explosivity: water content (primary, high water content more explosive, viscosity (secondary, high viscosity more explosive. What determines the type of eruption: viscosity of magma, high viscosity more explosive higher vei, volatiles (dissolved gas) in magma, high volatiles more explosive higher vei. What influences the viscosity of magma: chemical composition, oxygen and silicon (most abundant) sio 4 tetrahedron, high silica more internal attraction larger viscosity, temperature of magma, low temperature high viscosity. How does gas solubility relate to pressure and temperature: high pressure increases solubility, high temperature increases solubility. Low viscosity liquid easier for gases to escape. Solubility = amount of gas that can be dissolved in a liquid. How can you boil water: increase temperature, decrease pressure. What influences the nature of volcanic eruptions: sio 4 content, temperature of magma, viscosity, dissolved water, gas escape, volume, eruptive style, effusive, explosive.
