Oceanic crust is denser than continental crust because ____.
a. continental crust stands at a higher altitude
b. oceanic crust is rich in silica
c. oceanic crust is compressed at convergent boundaries
d. water pressure from the oceans makes oceanic crust thinner
e. oceanic crust is rich in iron- and magnesium-containing minerals
Question 2The concept of isostacy explains why ____.
a. magnetic differences exist in stripes along the seafloor
b. magma plumes are created
c. continental crust stands higher than oceanic crust
d. convection moves magma under the lithosphere
e. lithospheric plates move in response to convection
Question 3Compared to the lithosphere, the asthenosphere is ____.
a. cooler and more rigid
b. cooler and more plastic
c. hotter and more rigid
d. the same temperature and rigidity
e. hotter and more plastic
Question 4Which statement about the Earths is true?
a. The lithosphere is less dense than the asthenosphere, and located above it.
b. The lithosphere is denser than the asthenosphere, and located above it.
c. The lithosphere is less dense than the asthenosphere, and located below it.
d. The lithosphere is denser than the asthenosphere, and located below it.
e. The lithosphere and asthenosphere are equally dense.
Question 5Earths magnetic field played a crucial role in understanding subduction zones
a. True
b. False
Question 6The theory of continental drift was developed using the theory of plate tectonics.
a. True
b. False
Question 7Volcanoes are only formed at plate boundaries, and cannot exist in the middle of large plates.
a. True
b. False
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