key terms

Palaeomagnetism

Changes in earths magnetic field where it changes from magnetic North to magnetic South - stored in newly formed rock

Island arcs

Collection of volcanic islands formed 100km from the plate margin and found above an o/o subduction zone

Benioff zone

Depth at which the subduction zone causes melting of plate

Orogeny

Mountain building event

Viscosity

The resistance of a fluid to flow, where a high value means liquid does not like to flow (high viscous)

Volatiles

Components of magma which are dissolved (water and carbon dioxide) until it reaches the surface where they expand and explode - the more volatiles the more explosive

Silica

A hard, unreactive, colourless mineral - one of the most abundant elements on earth, contained within magma and main ingredient in sand

Mitigation

The action of reducing the severity, seriousness or painfulness of something