Plate Tectonics: A Unified Theory for Change of the Earth's Surf

What is the theory that the surface of the earth is broken into larger pieces of crust called plates that ride along on a softer layer of the earth, known as the asthenosphere?

• Volcanic eruption
• Magnetic reversal
• Plate tectonics
• Continental drift

What is the asthenosphere?

• A type of igneous rock
• A layer of the Earth's atmosphere
• The outermost layer of the Earth's crust
• The upper part of the mantle

True or False: continental plates are thicker than oceanic plates

• True

• False

Plate tectonics is the theory that the Earth's _____ is broken into pieces that move around on top of the _____.

• 1. mantle; crust

• 1. crust; core

• 1. crust; mantle

• 1. mantle; core

Using an apple as a model of the earth, the peel, fruit, and core represent, in order:

• 1. mantle, crust, and core

• crust, mantle, and core

• crust, core, and mantle

• core, mantle, and crust