Intro to Plate Tectonics

names of layers of the planet

lithosphere, asthenosphere, mantle, core

names of all lithospheric plates

african, arabian, eurasian, indian, indian-australian, phillipines, antarctic, pacific, nasca, cocos, caribbean, south american, juan de fuca, north american

types of boundaries between plates

divergent, convergent, transform

types of faults

normal, reverse, strike-slip

evidence for plate tectonics

rocks, fossils, climate, puzzle fit, glaciers, sea floor spreading, ocean island chains, volcanoes over subduction zones, magnetic striping

Lithosphere

the outher rigid shell of the earth, continental and oceanic crust

continental crust elements

Al, Si, K

oceanic crust elements

Fe, Mg, Ca

types of stress

shearing, tension, compression

fault

a fracture zone of fractures where the two sides move past each other

normal fault

the block above the fault (hanging wall) moves down relative to the block below the fault (foot wall)

caused by tensional forces

results in extension

reverse fault

the hanging wall moves up relative to the foot wall

caused by compressional forces

results in shortening

thrust fault if the dip of fault plane is small

strike-slip fault

most movement is horizontal

caused by shearing forces

transform fault

a type of strike-slip found on mid-ocean ridges or in regions of significant stretching from tension

divergent plate boundary

an area beneath the ocean where tectonic plates move away from each other

convergent plate boundary

A tectonic plate boundary where two plates collide, come together, or crash into each other.

transform plate boundary

Boundary between two plates that are sliding past each other.

how do we know earth's layers?

P and S wave shadow-zones

p wave

primary, compressional, 6km/s in crust, travels through solid, liquid, gas

s wave

secondary, shear, 2km/s, only travels through solid