Seismic Waves and Earth's Interior

Base your answer to the following question on the cross section below, which shows the paths of seismic waves traveling from an earthquake epicenter through the different layers of Earth's interior.

• P-waves are absorbed and S-waves are refracted by Earth's outer core

• P-waves are refracted and S-waves are absorbed by Earth's outer core

• both the P-waves and S-waves are refracted by Earth's outer core

• both the P-waves and S-waves are absorbed by Earth's outer core

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

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

Compared to the oceanic crust, the oceanic crust is usually

• thicker, with a more dense basaltic composition

• thicker, with a less dense granitic composition

• thinner, with a less dense granitic composition

• thinner, with a more dense basaltic composition

What is the approximate Pressure at a depth of 3900km within the Earth?

• 1.0 million atmospheres

• 2.1 million atmospheres

• 3.1 million atmospheres

• 3.4 million atmospheres

Why does the oceanic crust sink beneath the continental crust at a subduction boundary?

• The oceanic crust is pulled downward by Earth's magnetic field.

• The oceanic crust has a greater density.

• The continental crust has a more mafic composition.

• The continental crust is pulled upward by the Moon's gravity.

Scientists have inferred the structure of Earth's interior mainly by analyzing

• the Moon's interior

• the Moon's composition

• Earth's surface features

• Earth's seismic wave data

Which layer of Earth's interior is inferred to be composed mostly of iron and nickel, and has an interior temperature that is greater than its melting point?

• plastic mantle

• stiffer mantle

• outer core

• inner core

Earth's interior at a depth of 3500 kilometers is believed to be

• liquid at a temperature of approximately 4900°C

• solid at a temperature of approximately 4900°C

• liquid at a temperature of approximately 5400°C

• solid at a temperature of approximately 5400°C

Model A best represents the motion of earthquake waves called

• P-waves (compressional waves) that travel faster than S-waves (shear waves) shown in model B. P waves pass through all layers of the earth

• P-waves (compressional waves) that travel slower than S-waves (shear waves) shown in model B.

  P waves pass through all of the layers of the earth.

• S-waves (shear waves) that travel faster than P-waves (compressional waves) shown in model B. S waves pass through solids only.

• S-waves (shear waves) that travel slower than P-waves (compressional waves) shown in model B.

  S waves and pass through all layers of the earth.