Tectonics Definitions Flashcards
Magma
The molten materials inside the earth’s crust
Lava
When molten material is ejected at the earth’s surface through a volcano or crack called a fissure
Earthquake
The sudden, violent shaking of the ground following a build up of pressure
Deep focus
Earthquakes associated with subduction zones
Shallow focus
Earthquakes located along constructive and conservative boundaries
Epicentre
The point on the ground surface immediately above the focus
Richter scale
Measures magnitude of an earthquake
Mercalli Scale
Measures impacts of earthquakes
Crater
The giant hole left by a volcanic eruption
Vent
A long tube or pipe that allows magma to escape at the surface
Magma chamber
An underground store of magma
Volcano
An opening in the earth’s crust through which hot molten magma, molten rock and ash are erupted onto the land
Active volcano
A volcano that has erupted recently and is expected to erupt again
Dormant volcano
A volcano that has erupted in recent history and is expected to erupt again
Extinct volcano
A volcano that is unlikely to ever erupt again because no magma is being produced under it
