Plate Tectonics

Front 1

asthenosphere

Back 1

plastic like layer of earth on which the lithosphereplates float and move around

Front 2

continental drift

Back 2

Wegener's hypothesis that all continents were once connected in a single large landmass that broke apart 200 million years aga anddrifted slowly to their current positions

Front 3

convection current

Back 3

current in Earth's mantle that transfers heat in Earth's interior and is the driving force for plate tectonics

Front 4

lithosphere

Back 4

rigid layer of the Earth about 100 km thick made of the crust and a part of the upper mantle

Front 5

Pangaea

Back 5

large ancient landmass that was composed of all the continents joined together

Front 6

plate

Back 6

a large section of Earth's oceanic or continental crust and rigid upper mantle that moves around on the asthenosphere

Front 7

plate tectonics

Back 7

theory that Earth's crust and upper mantle are broken into plates that float andmove around ona plastic like layer of the mantle

Front 8

seafloor spreading

Back 8

Hess's theory that the new seafloor is formed when magma is formed upward toward the surface at mid ocean ridge

Front 9

What does seafloor spreading have to do with continental drift?

Back 9

sea floor spreading causes the continents to move

Front 10

magnetic field reversal

Back 10

-south pole and north pole switched places at one point
- lines of magnetic force run the opposite way

Front 11

Glomar Challenger

Back 11

- research ship
- found evidence of coninental drift and seafloor spreading

Front 12

subduction

Back 12

forms where two oceanic plates coverage

Front 13

faults

Back 13

transform boundries
- San Andreas Fault

Front 14

Convergent

Back 14

moving together

Front 15

Divergent

Back 15

moving apart

Front 16

Transform

Back 16

sliding past each other