Plate Tectonics - Glossary

Key Words

Definitions

Acid Lava

Thick viscous lava which flows short distances

Basic Lava

Thin , runny lava which can flow long distances

Composite Volcano

Steep sided cone with layers of ash and lava

Compress ional Margin

This is where two plates move together

Core

The centre of the earth

Crater

The mouth of the volcano

Crust

The thin layer of the earth's surface

Earthquake

A shaking of the earth's crust

Epicentre

The point within the earth's crust where the earthquake occurred

Focus

The point on the earth's surface directly above the epicentre

Fold Mountains

Mountains formed by the earth's movements

Geosynclines

A depression between two plates

Lava

The name given to liquid magma when it reaches the surface of the earth

Mantle

The molten rock that surrounds the earth's core

Richter Scale

This measures the strength of the earthquake

Shield Volcano

A gentle sided volcano with a wide base made up of basic lava

Subduction Zone

Where a plate sinks and slides under another plate

Tectonic Plate

A huge section of the earth's crust

Tensional Margin

Where two plates move apart

Transhumance

Method of farming found in Alpine areas

Tsunami

Huge tidal waves that are caused by submarine earthquakes

Vent

The opening through which the lava flows in a volcano

Volcano

A cone shaped mountain created by lava and ash being erupted from the earth