Topic 5 - Tectonic Plates Flashcards
Asthenosphere
A layer of semi solid rock in the lower mantle on which earths tectonic plates move
Constructive boundary
Plate boundary where new crust is formed
Destructive boundary
Plate boundary where lithosphere is destroyed
Continental crust
The crust that forms the continents
Continental drift
The separating of continents by drifting across earths surface
Converging boundary
Where plates are colliding with each other
Diverging boundary
Where plates are moving apart from each other in opposite directions
Core
The centre of the earth
Earthquake
The rapid movement of the ground, due to the movement of tectonic plates
Epicentre
The point directly above the focus of an earthquake on the earths surface
Focus
The place below ground where an earthquake starts
Fold mountain
Mountain formed by crust crumpling upwards as plates collide
Hot spot
Isolated place away from plate boundaries where a lot of hot magma is collecting
Island arcs
A chain of islands formed at the edges of colliding tectonic plates where one subducts
Lithosphere
Name for the crust and upper mantle together; earths tectonic plates
Magnetic striping
Patterns of magnetism trapped in rocks on each side of plate boundaries
Mantle
Layer beneath earths crust
Ocean trench
A deep channel in the ocean floor where crust is sinking downwards
Oceanic crust
The crust that forms the ocean floor
Ridge push
Older crust is pushed below new ocean crust and squeezes the plates sideways
Rift
A zone where the earths crust and mantle are being pulled apart
Rifting
The process of continents breaking up, subsiding and allowing in sea water
Seafloor spreading
The process of new crust forming at ocean ridges and spreading outwards
Primary wave (P wave)
A longitudinal seismic wave that travels fast through the earth
