continetial crust characteristics
- thick
- old
- lighter
- granite, silicon, aluminum and oxygen
oceanic crust characteristics
- thin
- younger
- heavier
- basalt, silicon, magnesium
convection currents
core generates high temperatures which heats the lower mantle
gravitational sliding
lithosphere thickens with distance from mid ocean ridge because it cools
landforms associated with palte movements
- ocean ridges
- rift valley
- deep sea trenches
- island arcs
- fold mountains
ocean ridges
continuous uplift feature on surface
- it breaks the surface creating an island
- space between two plates is filled with lava
rift valley
plates move apart on land
- east africa moving away from african continent
deep sea trenches
oceanic and continental plates meet
- denser oceanic plate submerges creating a trench
island arcs
decedning plate into hot subduction zone creates friction
- less dense material rises as magma surfaces and forms volcanoes along tectonic boundaries
fold mountains
continental plates meet and sediment pushes up
- some material forms deep roots
- andes mountains
global distribution of tectonic hazards
clear patterns of volcanic and seismic activity along north/south america or in atlantic ocean
- ring of fire
constructive plate margin
plates move away from each other and magma rises in the gap
shield volcanoes
- sea floor spreading (oceanic)
- rift valley
destructive plate margin
plates move towards each other
one plate subducts (oceanic)
- ocean trench and fold mountains
- composite volcanoes
conservative plate margins
plates move alongside eachother
oceanic conservative causes tsunamis
- fault lines
- earthquakes
