Dynamic Earth

Name given to a supercontinent that began to break apart approximately 200 million years ago.

Igneous rock that forms as magma cools underground.

Wegener's hypothesis that all continents were once connected in a single large landmass that broke apart about 200 million years ago and drifted slowly to their current positions.

A deep, underwater trough created by one plate subducting under another plate at a convergent plate boundary.

The process that occurs when one tectonic plate moves under another tectonic plate.

The process by which new oceanic crust forms along a mid ocean ridge and older oceanic crust moves away from the ridge.

Molten rock stored below Earth's surface.

Magma that erupts onto Earth's surface.

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

Long, narrow mountain range on the ocean floor; formed by magma at divergent plate boundaries.