Earth's Crustal Recycling System

Multiple Choice

Which of the following processes are involved in recycling Earth's crust?

• Sea-floor spreading and subduction

• Weathering and erosion

• Photosynthesis and respiration

• Condensation and precipitation

Multiple Choice

What drives the movement of Earth's crust, causing new surfaces to be created and old surfaces to be recycled?

• Wind currents in the atmosphere

• Immense heat from Earth's interior

• Ocean tides

• Solar energy

Fill in the Blank

As new oceanic crust moves away from the ridge, it ___ and becomes denser.

Multiple Choice

Why doesn't Earth get bigger even though new crust is constantly being formed at mid-ocean ridges?

• Because the new crust is lighter than the old crust

• Because old crust is destroyed at subduction zones

• Because the ocean absorbs the new crust

• Because continents shrink to balance the new crust

Multiple Select

Which of the following statements about subduction are correct?

• Subduction occurs when denser oceanic crust dives beneath a lighter plate

• Subduction zones are where new crust is created

• Subduction returns crust material to the mantle

• Subduction only happens at mid-ocean ridges

Multiple Choice

How does the process of sea-floor spreading and subduction contribute to the recycling system of Earth's crust?

• Sea-floor spreading creates new crust at mid-ocean ridges, while subduction destroys old crust at convergent boundaries, maintaining a balance.

• Sea-floor spreading destroys old crust at mid-ocean ridges, while subduction creates new crust at convergent boundaries.

• Both sea-floor spreading and subduction create new crust at different boundaries.

• Both sea-floor spreading and subduction destroy old crust at different boundaries.