What steps does the oceanic lithosphere go through to achieve the density required for subduction? Be as specific as possible
What will be an ideal response?
The lithosphere becomes denser than the asthenosphere by cooling. As the oceanic lithosphere moves away from the mid-ocean ridge, the lithosphere cools off and becomes denser. The lithosphere also becomes thicker because more of the original asthenospheric mantle becomes part of the cool, solid lithosphere. Once the lithosphere becomes sufficiently thick and dense, it will be able to sink into the asthenosphere due to density contrasts. As the slab sinks, it also reaches metamorphic temperatures and pressures and part of the slab converts into rock that is also very dense (eclogite).
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Herbivory is actually a type of ________
A) mutualism B) primary succession C) coevolution D) competition E) predation
The landform feature you have profiled is a drumlin. Drumlins are formed by glacial deposits and are streamlined in the direction of the glacier’s movement. They have a blunt end upstream, a tapered end downstream, and a rounded summit. Using your protractor, what direction was the glacier flowing?
Use the profile constructed in Figure 23.5 to answer the question and completion items.
What will be an ideal response?
Slow mass movements
A)are undetectable B)do not transport as much material as fast mass movements C)are characterized by tilted trees and cracked foundations D)are characterized by talus piles E)occur only on steep slopes
The term "system," as defined by geographers, means:
a. a set of objects whose size, shape, and temperature can be measured b. a set of objects linked together by their relationships to one another c. a set of objects comprised of continents, oceans, forests, and deserts d. a set of objects completely independent of one another