Corina De La Cerda Mr. Lee / science November 26 , 2011 1) What factors determine the type of volcanic eruption? Magma composition Magma temperature Amount of dissolved gases from the magma 2) List the materials ejected from volcanoes Lava, Broken rocks, Lava bombs, Fine ash, Dust, and Large amounts of gas 3) Describe the three types of volcanoes. Shield volcanoes Fluid basaltic lava Broad, slightly domed structure Grow from the ocean floor (creates islands) Cinder cones Cinder cones have a simple shape Eject lava fragments Very simple shape
Composite cones Earths most beautiful and potentially dangerous volcano Very large, nearly symmetrical structure The product of gas-rich magma 4) What is a caldera? A large depression in a volcano 5) Compare the formation of a plateau with the formation of a cinder cone. They form the same, but the cinder cone ends up having a big hoe in the middle of it, and a lava plateau ends up with just the lava that hardened inside the pipe. 6) What type of eruption produces a viscous magma containing 53 percent silica and a gas content of 2 percent? Basaltic ) If a pyroclastic flow was traveling 145 kilometers per hour, how long would it take to reach a town 2. 5 kilometers from the volcanoes crater? 58 seconds 10. 3 Assessment 1) How are the locations of a volcano related to plate boundaries? The plate boundaries motions provide the mechanism by which mantle rocks melt to generate magma. 2) What causes intraplate volcanism? Material called a mantle plume rises toward the surface. 3) Where is most of magma produced on Earth on a yearly basis? The mid-ocean ridges 4) What is the Ring of Fire? The concentration of volcanoes encircling the Pacific basin. ) What are the differences between volcanic island arcs and continental volcanic arcs? A volcanic island arc is a volcano that started at the ocean floor and arose above the water; a continental volcanic arc is created by subduction. 6) Would it be more likely for a major explosive eruption to occur at an ocean ridge or at a convergent ocean-continental boundary? Explain your answer. A major explosive eruption is more likely to occur at a convergent ocean-continental boundary. The plates are coming together and the pressure creates a more explosive eruption, than an eruption at a ocean ridge.