Tectonic Hazards Key Words

Plate tectonics

The study of the movement of the earth's crustal plates

Convection currents

Pockets of warm liquid that rise, cool and fall in a circular motion in the earth's mantle layer

Constructive plate boundaries

Where tectonic plates move apart and new oceanic crust is created

Destructive plate boundaries

Where tectonic plates are forced together, oceanic crust is destroyed and continental crust
is buckled and folded

Conservative plate boundaries

Where tectonic plates move alongside each other

Collision plate boundaries

Where tectonic plates collide, but create fold mountains as continental crust is involved

Hotspots

A place where lava rises up through very thin oceanic crust

Tectonic plates

Huge sections of the earth's crust. The margin between the plates is where most tectonic
activity occurs

Subduction

When a dense oceanic plate is forced under a continental plate at a destructive plate
boundary

Shallow focus earthquakes

An earthquake that starts within 70km of the earth's surface

Deep focus earthquakes

An earthquake that starts 70-700km below the earth's surface

Shield volcanoes

A gently-sloping volcano, formed by runny lava, usually at a constructive boundary

Composite volcanoes

A steep-sided volcano, formed by alternate layers of ash and lava on destructive boundaries

Mitigation

Action taken to make something less severe and reduce the impact e.g. of a hazards by
planning, prediction and preparation