Tectinic Theory Flashcards
Crust of earth: depth, material
5-10km deep, continental made of granite and dual
Oceanic made of basalt
Mantle: it’s components, depth, temp
2900km, 1600c made of soild lithosphere and liquid astenosphere
Outer core: materials, temp, depth
Iron and Nickel, 4000c (liquid) 2200km thick
Inner core: material, temp, depth
Iron and Nickle, 6000c (soild), 1270km thick
What did Alfred Wegener say
Works was once a super continent (Pangaea)
What did harry Hess say
Paleomagnetism which is sea floor spreading every 400,000 years due to earth magnetic field switching polarity
What are hotspot volcanoes
an area of the Earth’s mantle from which hot plumes rise upward, forming volcanoes on the overlying crust.
Divergent plate boundary’s
2 plates move away from each other,
What happens when 2 continental plates move away from each other
Magma rises to fill gap, creating rift valleys
What happens when 2 oceanic plates move away from each other
A sub marine volcano is formed
Convergent plate boundaries
2 plates move toward each other, if two oceanic plates then the faster, denser plate subducts
What happens if oceanic and continental plate move towards each other
Oceanic plate subducts under continental plate as denser
What happens if 2 continental plates moves toward each other
Fold mountains are formed
Conservative plate boundaries
2 plates slide past each other, moment is sinistral (to left) or dextral ( to right) this results in shallow earthquakes being formed
Intra plate earthquakes
Occur in middle or interior plates and are much rarer than boundary earthquakes (only 5%)
