01:460:100 Lecture Notes - Lecture 9: Lava Dome, Pyroclastic Flow, Andesite

• School: Rutgers University
• Department: Geological Sciences
• Course: 01:460:100
• Professor: Mark Feigenson

Document Summary

Chapter 9 - the wrath of vulcan: volcanic eruptions. An erupting vent through which molten rock surfaces. Volcanoes are a clear result of tectonic activity. Volcanoes pose a number of hazards to humans. A record of roman life was preserved under ash. Unpredictable, dangerous - build large & blow mountains to bits. Eruptions can provide highly productive soils to feed a civilization. Can extinguish a civilization in a matter of minutes. The products of volcanic eruption take three forms: Lava flows molten rock that moves over the ground. Pyroclastic debris fragments are blown out of a volcano. Volcanic gases vapor and aerosols that exit a volcano. Lava can be thin and runny or thick and sticky. Composition depends on silica (sio2), fe, and mg. Lavas with high silica / low fe and mg are calledsilicic, felsic, or rhyolitic. Rhyolite - the highest sio2 the most viscous lava. Rather, lava plugs the vent as a lava dome.