The Earth - Quiz 4

1. Scientists think the Earth's core is composed mainly of
A).. silicate rocks.
B).. uranium.
C).. lead.

2. Our knowledge of the composition of the Earth's core comes from
A)...analysis of earthquake waves.
B)... x-ray pictures taken with a powerful device in Russia.
C)...samples obtained by drilling deep holes.
D)... analysis of the material erupted from volcanoes.
E)... Both (c) and (d).

3.The slow shifts of our planet's crust are believed to arise from
A)... the gravitational force of the Moon pulling on the crust.
B)... the gravitational force of the Sun pulling on our planet's crust.
C)... the Earth's magnetic field drawing iron in crustal rocks toward the poles.
D)... heat from the interior causing convective motion, which pushes on the crust.
E)...the great weight of mountain ranges forcing the crust down and outward from their bases.

4. If the shape of the Earth's orbit was unaltered but its rotation axis was shifted so that it had no tilt with respect to the orbit, seasons would be
A)... essentially as they are now.
B)... more extreme, with colder winters and hotter summers.
C)...essentially nonexistent, with little temperature change at a given place throughout the year.
D)... Not enough information is given to make a reasonable guess.
E)... Either (a) or (b) is most likely.

5. What evidence indicates that part of the Earth's interior is liquid?
A)...With sensitive microphones, sloshing sounds can be heard.
B)... We know the core is lead, and we know the core's temperature is far above lead's melting point.
C)... Deep bore holes have brought up liquid from a depth of about 4000 kilometers.
D)... No S type of seismic waves are detectable at some locations after an earthquake.
E)... S type of waves are especially pronounced at all locations around the Earth after an earthquake.

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