Plate Boundaries

Rift

A deep crack in the Earth's surface associated with divergent boundary.

Trench

A surface feature in the seafloor produced by the descending plate during subduction.

Convection Currents

Circular currents in the mantle caused by the magma being heated by the core off the Earth.

Mountain Range

Formed by two continental plates colliding and forcing each other upwards.

Theory of Continental Drift

Proposed by Alfred Wegener, that the continents were once joined together and have since drifted apart.

Convergent Boundary

The boundary between two colliding plates, often associated with mountain building, ocean trenches and volcanic islands

Ridge

The highest part of a chain of underwater mountains.

Subduction Zone

The region where an oceanic plate sinks down into the asthenosphere at a convergent boundary, between continental and oceanic plates.

Asthenosphere

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

Lithosphere

The solid part of the earth consisting of the crust and outer mantle.

Theory of Plate Tectonics

The theory that the lithosphere is divided into tectonic plates that move around on top of the asthenosphere.

Divergent Boundary

Where two plates are moving apart, magma comes up to create new crust.