Earth's Moving Surface and Plate Tectonics

Vocabulary flashcards covering key terms and concepts related to Earth's moving surface, plate tectonics, plate boundaries, and mantle convection.

Plate Tectonics

The theory stating that Earth's surface is broken into large, rigid pieces that move with respect to each other.

Tectonic Plates

Large, rigid pieces of Earth's surface that move very slowly over Earth's surface, forming volcanoes and mountains and causing earthquakes.

Crust

Earth's outermost layer.

Lithosphere

The rigid outer layer of Earth made up of the crust and the uppermost part of the mantle.

Asthenosphere

The partially melted portion of the mantle located directly below the lithosphere that bends more easily because it is hotter.

Relative Motion

The movement of a tectonic plate described in relation to another plate.

Divergent Boundary

A boundary where two tectonic plates move away from each other, allowing new crust to form between them.

Convergent Boundary

A boundary where two tectonic plates move toward each other.

Subduction

The process that occurs when one tectonic plate moves under another tectonic plate and sinks into the mantle.

Transform Boundary

A boundary where two tectonic plates slide past each other.

Global Positioning System (GPS)

A network of satellites used to accurately measure the position of points on Earth's surface to determine the speed and direction of plate movement.

Pangea

A large continent that existed about $200\text{ million years}$ ago before North America and Europe separated and the Atlantic Ocean formed between them.

Density

The amount of matter per unit of volume.

Convection

The circulation within fluids caused by differences in density and thermal energy, which occurs in the mantle and can drag tectonic plates across Earth's surface.