EOSC 114 Volcanic Eruptions Exam Bank Solution Manual Already Passed

EOSC 114 Volcanic Eruptions Exam Bank Solution Manual Already Passed What are the 2 main types of Volcanic Eruptions? - Answers Effusive and Explosive Effusive - Answers outpouring of molten magma from the vent, lavas Explosive - Answers Gas driven violent eruptions, pyroclastic deposits Why does gas content matter? - Answers Magmas produce bubbles, bubbles expand as the magma rises lower pressure forming leads to explosivity What determines the eruption style? - Answers Viscosity and gas content Why does high viscosity promote high explosivity? - Answers Because bubbles cannot easily escape from highly viscous magma Hawaiin - Answers Low viscosity, basaltic, magma low explosively Lava flows, lava lake, fire fountaining Strombolian - Answers Basaltic/andesitic magma Mildly explosive Lava fountain, volcanic bomb, lava flow Vulcanian - Answers Viscous andesitic/ rhyolite magma Very explosive Ash plume, lapilli, volcanic ash rain, volcanic bomb Plinian - Answers Andesitic/rhyolitic ash Violently explosive ash plume, volcanic ash rain, pyroclastic flows What type of caldera or super volcano produce? - Answers Plinian or Ultra Plinian What does adding water to the mix do to the explosively of an eruption? - Answers It increases it due to rapid heating of water and It increases the explosion by turning into vapor instantly Phretomagmatic - Answers Contact between water and magma where water flashes to steam Characteristics: water vapour cloud, compressed ash, crater, water What measures the eruption size of a volcano on a scale of 0-8 - Answers Volcanic Explosivity Scale (VEI Scale) What characteristics determine the eruption size? - Answers Volume of ash produced Height of eruption cloud above the vent