Earth's Interior

Which two Earth layers are separated by the Moho boundary?

• rigid mantle and plastic mantle

• outer core and stiffer mantle

• stiffer mantle and asthenosphere

• crust and rigid mantle

Base your answer on the diagram of Earth shown. Letters B, C, and D represent layers of Earth. Letter Q represents a location on Earth's surface. Which letter best represents Earth's mantle?

• Q

• B

• D

• C

Which part of Earth's interior is inferred to have convection currents that cause tectonic plates to move?

• rigid mantle

• asthenosphere

• outer core

• inner core

Earth’s outer core is best inferred to be

• liquid, with an average density of approximately 4 g/cm3

• solid, with an average density of approximately 4 g/cm3

• liquid, with an average density of approximately 11 g/cm3

• solid, with an average density of approximately 11 g/cm³

Why is Earth’s outer core inferred to be a liquid?

• P-waves can pass through the outer core.

• P-waves cannot pass through the outer core.

• S-waves can pass through the outer core.

• S-waves cannot pass through the outer core.

From the top of the stiffer mantle to the center of Earth, the rock material is inferred to be

• solid all the way to the center of the inner core

• solid, then liquid to the center of the inner core

• solid, then liquid, then solid again to the center of the inner core

• solid, then liquid, then gaseous to the center of the inner core

In the Earth's interior, which zone has a temperature higher than its melting point?

• crust

• stiffer mantle

• inner core

• outer core

Compared to the oceanic crust, the continental crust is usually

• thicker, with a less dense granitic composition

• thicker, with a more dense basaltic composition

• thinner, with a less dense granitic composition

• thinner, with a more dense basaltic composition

Which pair of elements makes up most of Earth's crust by volume?

• nitrogen and potassium

• oxygen and silicon

• hydrogen and oxygen

• potassium and oxygen

The interior of Earth between a depth of 5200 kilometers and 6300 kilometers is inferred to be composed mostly of

• silicon and iron

• silicon and oxygen

• iron and lead

• iron and nickel