Convection is the engine driving the motions of the lithosphere and crust.

The Earth is comprised of 14 rigid continental and oceanic tectonic plates:

These plates "float" on an "ocean" of hot magma called the asthenosphere. Each plate contains a layer of crust and a layer between the crust and asthenosphere called the lithosphere.

	This is an example of a converging continental plate with another continental plate. This motion is responsible for mountain formation.
	This is an example of a converging ocean plate with a continental plate. The crust layer of an ocean plate is much thinner than its continental counterpart, so magma from the asthenosphere can penetrate.
	This is an example of two converging ocean plates. This is the type of convergence that resulted in the 9.0 Indonesian earthquake resulting in the tsunami.
	The only ocean only plate is the Pacific Plate. Because of the ocean-continental interactions resulting in potential volcanism, the area surrounding the Pacific Plate is called the Ring of Fire.

Interactions between these plates result in sea floor spreading, earthquakes, volcanoes and mountain formation.

There are 5 types of tectonic movement: mid-ocean ridge, oceanic plate meeting (example - Mt. Pinatubo), diving plates (example - Andean Mountains), sliding plates (example - San Andreas Fault), and colliding plates (example - The Alps).

The shifting of these plates is such that there are 7 major periods of continental drift:

There are three main categories of rock: igneous rocks, sedimentary rocks and metamorphic rocks.

There are several methods of land shaping: coastal waters, ground water, rivers, meanders, deltas, drainage basins, and gullies.

There are 5 major oceans: the Pacific Ocean, the Atlantic Ocean, the Indian Ocean, the Southern Ocean, and the Arctic Ocean.

There are 12 biographical regions:

There are 8 types of natural hazards (with an associated website):

The total population of Earth is around 5.5 billion people divided into 6 continental categories:

Back to Top