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27 Cards in this Set
- Front
- Back
- 3rd side (hint)
The depth of a hypocentres of earthquakes at oceanic spreading centres is how deep? |
Generally less then 80 km deep |
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The depth of hypocentres of earthquakes at subduction zones are how deep? |
Very variable, from near surface to to more then 500 km |
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As compared to the Asthenosphere, the lithosphere is... |
Cooler and less able to flow |
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Unlike the lithosphere, the Asthenosphere is... |
Is able to flow over long periods of time |
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Which lithosphere is thickest? |
Continental lithosphere |
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The lithosphere is generally thinnest near which plate boundary? |
Divergent plate boundaries |
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The lithosphere of the earth is generally thickest at or near which plate boundary? |
Convergent plate boundaries |
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The lithosphere is composed of the... |
Crust and upper most part of the mantel |
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The potential temperature of "normal" upper-mantel, away from hotspots, is accepted to be... |
1300 degrees Centigrade |
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The thermal gradient in the Asthenosphere is approximately... |
0.5 degrees C per km |
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The velocity of seismic waves traveling through from earthquake foci... |
Generally increase with depth, but with abrupt changes called "seismic discontinuities" |
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Do seismic waves travel at greater velocities in solids then in liquids? |
Yes |
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Can P waves travel through liquids? |
Yes |
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Are these two objects in isostatic equilibrium with one another? |
Yes |
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Why are hypothermal "black smokers" on the pacific sea floor black? |
Because of fine grained sulphide minerals suspended in super heated sea water. |
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This typical basalt erupted a the submarine environment. This lava flow morphology is commonly known as... |
Pillow basalt. |
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The boundary between the crust and the mantle is marked by a seismic velocity discontinuity called... |
The Moho |
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At oceanic spreading centers, earth's upper mantle is... |
The same temperature as elsewhere on earth. |
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Heat transfer in the crust is largely by... |
Conduction |
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Heat transfer in the Asthenosphere is largely by... |
Advection |
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The light green represents... |
The pressure and temperature conditions under which both melt and solid are present |
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The dark green represents... |
The pressure and temperature conditions under which the mantel is entirely molten |
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How does the mantle melt at oceanic spreading centers |
By decompression, with no significant thermal anomaly |
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At hotspots the mantle is of oder of _____ hotter then "normal" mentel |
200 degrees Centigrade |
Temp |
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The mantle melts at subduction zones as a result of... |
The addition of volatiles from dehydration of the down-going lithospheric slab |
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Hot spots are caused by... |
Hot plumes of mantle material that rises up from the core mantle boundary. |
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The diagram shows two subduction zones, with the down-going subducting plate moving from right to left. The depth of the earthquake hypocentres is shown by the coloured dots. What does this information tell us about the subduction slab? |
The slab dip is greater in B than in A |
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