Tectonics Flashcards
What are the features of an Oceanic crust?
Very Dense
Thin
Basalt
What are the features of a Continental crust?
Less dense
Thick
Granite
From the Core what are the Earths Layers?
Inner core outer core Lower mantle Upper mantle Crust
What are convection currents?
Convection occurs when particles with a lot of heat energy in a liquid or gas move and take the place of particles with less heat energy. Heat energy is transferred from hot places to cooler places by convection.
How do convection currents drive tectonic plates?
Where convection currents diverge near the Earth’s crust, plates move apart. Where convection currents converge, plates move towards each other.
Where do volcanoes and earthquakes form?
They occur along the boundary where tectonic plates meet.
Name the types of plate boundaries
Divergent < >
Convergent > <
Conservative ^ ^
What are the features of a Divergent plate?
> Plates move away from each other > Can be continental / oceanic > Small shallow earthquakes > Large shield volcanoes > oceanic ridges or islands may form
Examples of islands and ridges made by Divergent boundaries
Iceland
Mid-Atlantic Ridge – Eurasian + N American move apart.
What are the features of Convergent boundaries?
> Plates move towards each other
Only continental plates
Large earthquakes
Huge fold mountains
Examples of fold mountains formed on Convergent- continental - continental boundaries
Rockies
Himalayas – Indian and Eurasian plates collide.
What are the features of a Convergent Oceanic - Continental
> Plates move towards each other
Oceanic continental plates involved
Large earthquakes as the plates collide.
Large composite volcanoes as and lava is forced up under extreme pressures causing explosive eruptions.
Deep sea Ocean trenches (where the oceanic plate is subducted), continental volcanic arcs (chains of volcanoes on land) and volcanic island arcs (chains of volcanoes forming islands in the sea)
Examples of Convergent oceanic - continental plates
Andes mountains (Peru Chile) – Nazca subdued under. S
What are the features of a Convergent oceanic- oceanic boundary?
> Two plates moving towards each other > Both oceanic plates > Large earthquakes as plates collide > Large composite volcanos > Deep sea ocean trenches > Volcanic Island arcs
Examples of Convergent oceanic - oceanic boundary
Pacific plate is subdued below the Philippine plate. S