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46 Cards in this Set
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- 3rd side (hint)
______ are tall, steep-sided cones composed of interlayered lava and tephra. |
Stratovolcanoes |
Mount Shasta, California ; Mount St. Helens, Washington |
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The largest volcanoes in the world that are constructed from basaltic lavas and shaped with gentle arch or shield shape with shallow slopes and built up of many lava flows are ____? |
Shield Volcanoes |
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Basaltic magma rich in ____ and _____ forms shield volcanoes |
Iron and Magnesium |
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4 types of volcanoes |
Stratovolcanoes, Shield, Cinder Cones, Lava Domes |
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Because of their high ____, Stratovolcanoes' lavas don't travel far from the vent and therefore pile up, giving them their steep sides |
Viscosity |
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3 states with active Stratovolcanoes |
Washington, California, Oregon |
Westside of US |
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5 components of a Stratovolcanoes include : |
Magma Chamber, Conduit, Crater, Lava Flows, and Pyroclastic Flows |
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______ volcanoes consist mostly of intermediate composition rocks such as andesite |
Composite |
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Composite volcanoes form in Subduction Zones as lava erupts to form _____ and build _______ |
Island Arcs and Continental Margins |
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Similar to Stratovolcanoes, ______ are characterized by highly viscous felsic magma and are common along the Ring of Fire. However, they are relatively small and have ____ volatile content |
Lava Domes; low to moderate |
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Composed of basalt with low to moderate volatile content, _____ volcanoes are cone shaped with steep sides and summit crater. |
Cinder Cones |
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Parts of a Volcano |
Magma chamber, vent, crater, caldera, cone |
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The largest and most violent eruptions occur when ____ form due to collapse of land surface or volcanic opening following partial emptying of the magma chamber |
Calderas |
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_____ is formed when magma cools too quickly to form mineral crystals |
Obsidian |
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Although dark in color, most obsidian has a ____ composition similar to rhyolite |
Felsic |
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_____ form when material crystallized from magma is transported by wind, water, and gravity away from the site of a volcanic eruption |
Pyroclastic rocks |
Tuff, pumice, and scoria |
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Violent or explosive volcanic eruptions occur when ... |
Magma has more felsic composition, remains liquid at a lower temperature, and contains more dissolved gases |
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_____ are generally more viscous because they contain crystalline material as well as gases |
Felsic lavas |
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____ are lower in viscosity, are more fluid, and do not create violent or explosive eruptions |
Basaltic lavas |
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_______ of volcanoes include increasing the fertility of soils, providing a source or geothermal energy, enriching many rocks bodies with precious metals, creating scenic and culturally meaningful landscapes, and creating new land as habitat for pioneering organisms |
Natural Service Functions |
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Lava |
Molten material on the surface |
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Magma |
Molten material below surface |
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Tephra |
Igneous material, size from dust to boulders |
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Distribution of Volcanoes |
1. Most frequently with Subduction zones 2. Common along mid-ocean ridges 3. Some at hot spots, but much more rare |
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Magma chamber |
Molten rock beneath surface |
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Vent |
Opening used by magma to move from chamber to surface |
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Crater |
Opening through which lava and tephra issues |
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Caldera |
A very large crater created by explosion or collapse |
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Cone |
Build up of lava and/or tephra around a vent, creating a hill or mountain |
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Area where heat source located below the lithosphere that feeds overlying volcanic processes near surface |
Hot spot |
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Types of magma |
Basaltic, Andesitic, Granitic |
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Japanese for "large harbor wave" |
Tsunami |
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Four possible causes of a tsunami |
1. Subduction zone earthquake 2. Underwater landslide 3. Collapse of volcano 4. Asteroid impacts |
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____ must move the seafloor, commonly when a subducting plate pops loose along an area of "stick-slip." |
Earthquake |
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4 Stages of a tsunami |
1. Water domes up 2. Waves travel away from epicenter, fastest in deep ocean at up to 900km/h 3. Velocity decreases but wave height increases near land (amplification) 4. Wave runup will vary depending upon orientation, slope, and surface topography of coast |
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Distant vs. Local tsunami |
Distant: wave moves into the deep ocean Local: wave moves to adjacent coastline |
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December 26 , 2004 tsunami in the Indian Ocean was caused by a M ___ earthquake. |
9.1 |
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______ was hit first, within 15 minutes, and devastation was most acute in provincial capital or Bands Aceh |
Northern Sumatra |
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July ___, ___ local tsunami in the Sea of Japan was caused by a M ___ earthquake |
July 12, 1993 ; 7.8 |
120 people killed and $600 million in property damage |
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Tsunami precursors |
1. The earthquake itself 2. Sudden drop in water level at shorelines if the trough of a wave makes landfall first |
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Where do the tsunami waves travel fastest |
In the deep ocean |
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Tsunami waves can travel up to ___ km/h |
900 |
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Tsunami Warning System : "Tsunameters" include |
Surface buoy Bottom pressure recorders Depth gauges Public education |
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Tsunami Runup Map |
The height reached by previous tsunamis can help in planning for the next one |
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Tsunami Hazard Map |
Elevation, slope of sea bottom, orientation of coast |
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_____ of tsunami including addition of nutrients from seawater to terrestrial soils and rocks, and adding sediment to terrestrial basins |
Natural Service Functions |
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