17 The hotter the lava, (the more/ less fluid it is.)
18 The hotter the lava, (the more fluid it is.) More fluid means the lava has a lower viscosity.Hotter lavaBack to Menu
19 The silica content helps determine whether the volcanic eruption is quiet or explosive. If the magma has a high viscosity the eruption is quiet/explosive and therefore the silica content must be high/low.
20 The silica content helps determine whether the volcanic eruption is quiet or explosive. If the magma is thick and sticky the eruption is explosive and therefore the silica content must be high.Back to Menu
21 This mountain range includes Mount St This mountain range includes Mount St. Helens, Mount Rainier, and Mount Shasta just to name a few. The range forms as a result of subduction of The Juan de Fuca Plate under the North American Plate.
25 Describe a the shape of a Cinder Cone and what type of eruptions make it that way.
26 A steep, cone-shaped hill. If lava is thick and stiff it may produce ash, cinders and bombs in explosive volcanoesParicutin in Mexico (farmers field 400m high)Back to Menu
27 What kind of a volcano is a tall, cone-shaped volcano which alternates eruptions of lava flows with explosive eruptions of ash, cinder and bombs.Name two examples:
28 Composite Volcanoes-examples are: Mount Fugi, Mount Vesuvius, and Mount St. Helens.Mount FujiMount VesuviusMount St. HelensBack to Menu
29 A Shield Volcano is wide at its base and forms from layers of thin/thick lava that is high/low in silica and has gentle/ steep slopes. An example of a Shield Volcano is…
30 A Shield Volcano forms from layers of thin lava that is low in silica and has gentle slopes. An example of a Shield Volcano is…Hawaii or IcelandBack to Menu
31 A divergent boundary is associated with: 1.explosive volcanoes, sea floor spreading, mountain building2.quiet volcanoes, island arc volcanoes, shield volcanoes3.quiet volcanoes, sea floor spreading, mid ocean ridge4.explosive volcanoes, island arc volcanoes, hot spots
32 A divergent boundary is associated with: sea floor spreading and quiet eruptions like those that formed Iceland. As the plates continue to diverge, Iceland will continue to get wider.Back to MenuFinal Jeopardy
33 Most volcanoes are found along plate boundaries Most volcanoes are found along plate boundaries. Are volcanic mountains and island arcs associated with convergent boundaries, divergent boundaries or hot spots? Why? Give 2 examples.
34 Volcanic mountains and Island Arcs occur at converging plates because the denser plate dives below the crust, melts and magma rises to the surface creating the volcano.Examples: Japan,Aleutian islands,New ZealandBack to Menu
35 Magma flows upward through cracks in rock because it is 1. highly magnetic2. highly fluid.3. less dense than the surrounding solid material.4. more dense than the surrounding solid material.ABCD
36 3. less dense than the surrounding solid material. Magma flows upward through cracks in rock because it is1. highly magnetic2. highly fluid.3. less dense than the surrounding solid material.4. more dense than the surrounding solid material.ABCDBack to Menu
37 Pyroclastic flows occur during the most dangerous kind of volcanic eruptions. Extremely hot gasses and fragments of rock travel down the sides of the volcano at speeds over 100 Km per hour killing and burying everything in their path. Pyroclastic flows are associated with what type of an eruption?
38 An explosive eruption. Pyroclastic flow occurs when an explosive eruption hurls out ash, cinders and bombs as well as gases.(400mph, 1,800˚F)Back to Menu
40 These people were killed instantly in the pyroclastic flow from the explosive eruption of Mt. Vesuvius in Pompeii, Italy in 79 A.D.Depiction of Mt Vesuvius 79 A.D.Excavated Pompeii today with Mt. VesuviusBack to Menu
41 These are huge holes that form when a volcanic eruption empties a magma chamber and the volcanic mountain above it collapses into the magma chamber.
43 What type of a volcano are the Hawaiian Islands? How did they form?
44 They are Shield Volcanoes They are Shield Volcanoes. Each Island was formed as the tectonic plate moved over the Hot Spot and the lava produced a volcanic mountain large enough to emerge through the surface of the ocean. A hot spot is a location where a column of extremely hot mantle rock, called a mantle plume, rises through the asthenosphere.Back to Menu
45 If geologists detect many small earthquakes in the area near a volcano, what can they infer about the volcano?It is a good source of geothermal energy.It is dormant.It is probably about to erupt.It is extinct.
46 It is a good source of geothermal energy. It is dormant. If geologists detect many small earthquakes in the area near a volcano, what can they infer about the volcano?It is a good source of geothermal energy.It is dormant.It is probably about to erupt.It is extinct.Back to Menu
47 List the 3 types of boundaries symbolized by the following motions.
48 Convergent, Divergent, and Transform boundaries. Back to Menu
49 Fissure eruptions occur when lava flows from giant cracks, or fissures, in the Earth’s crust. As a result, a thick and mostly flattened layer of cooled lava creates this landform.