Ocean trench near Batu Balong. Photo courtesy of NeilsPhotography/Flickr.
Licensed CC BY.

Abraham Ortelius: First known person to suggest that the Earth had a supercontinent in the past.

Alfred Wegener: Developed the first scientific theory of a supercontinent.

Asthenosphere: located beneath the lithosphere and is composed of solid, but plastic rocks.

Harry Hess: Proposed that the seafloor was spreading.

Pangaea: A supercontinent thought to have existed over 200 million years ago.

Plate boundaries: places on Earth in which two parts of the Earth interact with one another.

Plate tectonics: theory that the Earth's crust is moving as a series of large chunks as a result of continental drift and seafloor spreading.

Seafloor Spreading: theory that explains how new ocean crust is formed at mid-ocean ridges, and old oceanic crust is destroyed at ocean trenches.

Tectonic plate: large parts of the lithosphere.

Last modified: Saturday, 1 May 2010, 2:09 PM