Volcanoes Rozycki

5 Written Questions

1. A major belt of volcanoes that rims the Pacific Ocean and subduction zones.
2. said of a volcano that is unlikely to erupt again
3. a fissure in the earth's crust (or in the surface of some other planet) through which molten lava and gases erupt
4. A slab of volcanic rock formed when magma forces itself up rock layers vertically.
5. The lava that is richest in silica, making it the stickiest and least fluid kind of lava. It erupts at temperatures of only 600 to 800 C. Highly explosive, found at continental hot spots and subduction zones.

5 Matching Questions

1. dormant
2. island arc
3. Andesitic Lava
4. sill
5. lava flow

1. a A lava of intermediate composition that has a higher silica content than basalt, erupts at lower temperatures, and is more viscous. Extrusive equivalent of diorite. Found at subduction zones.
2. b The area convered by lava as it pours out of a volcano's vent
3. c said of a volcano that does not show signs of erupting in the near future
4. d A string of islands formed by the volcanoes along a deep ocean trench.
5. e A slab of volcanic rock formed when magma squeezes between layers of rock laying horizontal.

5 Multiple Choice Questions

1. large mass of intrusive igneous rock believed to have solidified deep within the earth
   1. Pluton
   2. lava
   3. crater
   4. vent
2. the pocket beneath a volcano where magma collects
   1. magma chamber
   2. magma
   3. caldera
   4. crater
3. The large hole at the top of a volcano formed when the roof of a volcano's magma chamber collapses.
   1. silica
   2. crater
   3. magma
   4. Caldera
4. Active strato-volcano in Washington state which erupted in 1980 and was the deadliest and destructive volcanic eruption in the U.S.
   1. Mount St. Helen's
   2. hot spot
   3. Ring of Fire
   4. composite volcano
5. Liquid magma that reaches the surface; also the rock formed when liquid lava hardens.
   1. magma
   2. aa
   3. sill
   4. lava

5 True/False Questions

1. hot spot → An area where magma from deep within the mantle melts through the crust above it.

   True        False

2. Basaltic Magma → The lava that is richest in silica, making it the stickiest and least fluid kind of lava. It erupts at temperatures of only 600 to 800 C. Highly explosive, found at continental hot spots and subduction zones.

   True        False

3. active volcano → A wide, gently sloping mountain made of layers of lava and formed by quiet eruptions.

   True        False

4. composite volcano → A tall, cone shaped mountain in which layers of lava alternate with layers of ash and other volcanic materials. Most violent of eruptions.

   True        False

5. shield volcano → A wide, gently sloping mountain made of layers of lava and formed by quiet eruptions.

   True        False