Chapter 4.2 Flashcards

Front 1

plate tectonics

Back 1

it describes continental movement but also proposes a possible explaination of why and how continents move. States: 1) Lithosphere broken into 30 plates
2) Plates dift ontop of convection Asthosphere

Front 2

oceanic crust

Back 2

the crust that lies beneath. the meterial on the ocean floor makes the oceanic crust think 5-10 km thick and dense

Front 3

continental crust

Back 3

the crust that lies beneath continents. also material that makes up landmasses Dense and it is 32-70 km thick (thickest under mountains)

Front 4

lithosphere

Back 4

thin outer shell of the earth consisting of the crust and the rigid upper mantle 65-100 km thick

Front 5

asthenosphere

Back 5

zone of mantle beneath the lithosphere that consists of slowly flowing solid rock 200 km thick

Front 6

divergent boundary

Back 6

boundary formed by two lithospheric plates that are moving apart

Front 7

rift valley

Back 7

steap narrow valley formed as lithospheric plates separate

Front 8

convergen boundary

Back 8

boarder formed by the driect collision of two lithospheric plate

Front 9

subduction zone

Back 9

reigion where one lithospheric plate moves under another

Front 10

ocean trench

Back 10

deep valley in the ocean floor that forms along the subduction zone

Front 11

island arc

Back 11

chain of valcanic islands formed along in ocean trench resualts when one ocean plate subducts under a ocean plate Ex: japan

Front 12

transform fault boundary

Back 12

boundary formed where two lithospheric plates slide past each other Ex: San Andrea's Fault

Front 13

convection

Back 13

transfer of heat through the movement of fluid material hot rises and cool sinks

Front 14

convection current

Back 14

movement in a fluid caused by uneven heating