1.2 Plate Tectonics Flashcards
Seismic waves
Shock waves released by Tectonic movement
Inner core
Centre of earth. Solid, mostly iron. 6000⁰C.
Outer core
Semi-molten, made of mostly liquid iron and nickel.
The mantle
Surrounds the core. Widest layer. Upper part is solid. Below is semi-molten. Part of it forms the asthenosphere. Area where Tectonic plates ‘float’
The crust
Oceanic crust: Thin and dense. Lines ocean floors.
Continental crust: Older and thicker, makes up Earth’s landmasses
Lithosphere
Solid layer between the crust and upper mantle where Tectonic plates are formed
convection currents
When the core heats the lower mantle. Hot liquid magma currents move in circles in the asthenosphere, moving the tectonic plates
Slab pull
Where newly formed oceanic crust becomes denser and thicker. Causes it to sink, pulling the rest of the plate down as well
Subduction
As two plates move towards each other, one slides under the other.
Seafloor spreading
When hot magma is forced up from the asthenosphere and hardens. Forms new oceanic crust. It pushes the tectonic plates apart
Convergent boundary
Where two plates collide, aka destructive margins
Divergent boundary
Where 2 plates move apart, aka constructive margins
Conservative boundary
When 2 plates move past each other, aka transform margins
3 types of convergent boundaries
Oceanic+continental plate
Oceanic+Oceanic plate
Continental+continental plate
Transform fault
Break in the ocean floor
