Earth Structure: A Virtual Journey to the Center of Earth

The Moho is the boundary between

• a.the lithosphere and the asthenosphere.
• b.the inner core and the outer core.
• c.the crust and the mantle.
• d.the mantle and the core.

Earthquakes are useful for studying Earth's interior because

• a.each earthquake produces an array of seismic waves.
• b.earthquakes are extremely destructive.
• c.they happen below the surface of the Earth.
• d.they release stress that has been stored.

Both S-waves and P-waves can travel easily through liquids.

• a.true
• b.false

Although we don't have any samples of the core, most scientists agree that its main constituent is

• a.basalt.
• b.granite.
• c.iron.
• d.peridotite.

Continental crust is ________________ than oceanic crust.

• a.thicker and less dense
• b.thicker and more dense
• c.thinner and less dense
• d.thinner and more dense

When seismic waves hit a boundary with a different material, they might

• a.reflect.
• b.refract.
• c.change velocity.
• d.all of the choices

What does the S-wave shadow zone indicate about Earth's interior?

• a.The core is made of iron.
• b.The mantle is denser than the crust.
• c.The mantle is liquid.
• d.The outer core is liquid.

Tectonic plates consist of the lithosphere, which is made up of the crust and the uppermost mantle.

• a.true
• b.false

How do we know that Earth is not the same composition all the way through?

• a.Seismic waves do not arrive uniformly all over the earth.
• b.There are two types of seismic waves, S- and P-waves.
• c.Where the mantle is exposed, it looks very different.
• d.Seismic waves attenuate with distance.