Plate Tectonics APES

Front

mantle

Back

The layer of the Earth between the crust and the core. It is about 2,900 km (1,798 mi) thick and consists mainly of magnesium-iron silicate minerals. The upper mantle is the source of magma and volcanic lava.

Front

asthenosphere

Back

Highly viscous, mechanically weak, and easily movable part of the upper mantle.

Front

lithosphere

Back

The rocky outer shell of a planet. On Earth, the lithosphere is the Earth's crust.

Front

divergent boundary

Back

A tectonic boundary where two plates are moving away from each other and new crust is forming from magma that rises to the Earth's surface between the two plates.

Front

convergent boundary

Back

A plate boundary where two plates come together (converge).

Front

transform fault

Back

This can occur when two plates slide past each other

Front

richter scale

Back

The scale that measures the intensity of an earthquake, the amplitude of the wave increases by a factor of 10, the energy intensity increases approximately 32 times.

Front

subduction zone

Back

When one tectonic plate moves under another into the mantle, as the plates converge.

Front

Geologic Hotspot

Back

An area where magma from deep within the mantle melts through the crust in the middle of a tectonic plate, e.g., Hawaii.

Front

sea-floor spreading

Back

The process by which molten material adds new oceanic crust to the ocean floor at a divergent boundary.