Earth Science Plate Tectonics Vocab

Front 1

Asthenosphere

Back 1

The soft layer of the mantle on which the lithosphere floats.

Front 2

Continental Drift

Back 2

The hypothesis that the continents slowly move across Earth's surface.

Front 3

Convection

Back 3

The transfer of heat by movements of a fluid.

Front 4

Convergent Boundary

Back 4

A plate boundary where two plates move toward each other.

Front 5

Divergent Boundary

Back 5

A plate boundary where two plates move away from each other.

Front 6

Lithosphere

Back 6

A rigid layer made up of the uppermost part of the mantle and the crust. One of the four spheres into which scientists divide the Earth.

Front 7

Mantle

Back 7

The layer of hot, solid material between Earth's crust and core.

Front 8

Mid-Ocean Ridge

Back 8

The undersea mountain chain where new ocean floor is produced; a divergent plate boundary.

Front 9

Plate

Back 9

A section of the lithospere that slowly moves over the athenosphere, carrying pieces of continental and oceanic crust.

Front 10

Plate Tectonics

Back 10

The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle.

Front 11

Ring of Fire

Back 11

A major belt of volcanoes that rims the Pacific Ocean.

Front 12

Sea-floor spreading

Back 12

The process by which molten material adds new oceanic crust to the ocean floor.

Front 13

Subduction

Back 13

The process by which oceanic crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary.