GEO 1111 Lecture Notes - Lecture 6: Volcanic Winter, Krakatoa, Mount Vesuvius

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: David Schneider

Document Summary

Shield volcano: wide with shallow slopes, formed by low viscosity lava-flows, multiple vents, non-explosive, found at: hot spots. Stratovolcano (composite: tall, steep and conical + snow, made up from layers of lava, tephra and volcanic ash, multiple vents, highly viscous lava flow, most explosive. Cinder cone volcano: bowl shaped crater at summit, mafic magma, single vent, highly viscous lava, explosive, found at: hot spots and subduction zones. Fissure volcano: mid-ocean ridges, basaltic magma (low si, found at: fissures. Volcanic domes: felsic magma, explosive + pyroclastic flows, found at: subduction zones. Igneous activity isn"t random: active volcanoes are closer or near water basins; there is a pattern along the plate tectonics, correlation between earthquakes and volcanism, volcanoes usually happen in subduction zones. Violence incidence: composition, high concentration of si = high lava velocity, temperature, low temperature = high lava viscosity, dissolved volatiles, water, co2, sulfur = high lava viscosity.