Chapter 9 answers

Chapter 9 answers - 1. In 1980, _ was the first Cascade...

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1. In 1980, _____________ was the first Cascade Range volcano to erupt since Mt. Lassen in 1915-16. a. Mt. Rainier b. Mt. Shasta c. Kilauea d. Mt. St. Helens 2. Which type of basaltic lava flow has a fairly smooth, unfragmented, ropy surface? a. aa b. pegmatitic c. pahoehoe d. scoria 3. ____________ is a major dissolved volatile constituent in both magmas and volcanic gases? a. Water b. Carbon monoxide c. Hydrogen chloride d. Methane 4. Volcanic bombs originate ____________. a. as laser-guided, granite blocks launched from a supersonic jet b. as blocks of volcanic rock ejected from an erupting volcanic crater c. as erupted magma blobs that partly congeal before falling to the ground d. as ash particles that join together in the eruptive plume and fall as cobble-sized objects 5. ____________ magma is the most abundant type of erupted at oceanic spreading centers. a. Basaltic b. Granitic c. Andesitic d. Pegmatitic 6. The 1991 Pinatubo eruption in the Philippines caused brilliantly colored sunrises and sunsets to be seen for the next few years. What caused this phenomenon? a. the eruption added large amounts of carbon dioxide to the atmosphere b. the eruptive cloud destroyed parts of the Earth's protective ozone layer c. radioactive atoms blown into the atmosphere glowed red as they decayed d. sulfur dioxide and other erupted gases formed aerosols in the stratosphere 7. The ___________ ocean basin is rimmed by the most subduction zones. a. Atlantic b. Indian c. Pacific d. Arctic 8. Which of the following factors help determine whether a volcanic eruption will be violent or relatively quiescent? a. amount of dissolved gas in the magma b. temperature of the magma c. composition of the magma d. all of these
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9. Which of the following is associated with deep mantle hot spots? a. Vesuvius and the other volcanoes of Italy b. the volcanoes of Hawaii and Yellowstone National Park c. the very young cinder cones scattered across the southwestern United States d. Mt. St. Helens and other volcanoes of the Cascade Mountains 10. Cinder cones __________. a. have very steep slopes
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Chapter 9 answers - 1. In 1980, _ was the first Cascade...

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