8th grade Earth Science

asthenosphere
- part of the mantle; a layer of earth compared to road tar that is softened by the sun and can bend like plastic (p. 21)
pressure
- the amount of force pushing on a surface (p. 19)
density

the amount of mass in a given space; mass per unit volume (p. 26)
convection
- the transfer of heat by movements of a heated fluid (p. 26)
convection current

the movement of a fluid, caused by diffferences in temperature, that transfers heat from one part of the fluid to another (p. 26)
sea floor spreading

the process by which molten material adds new oceanic crust to the ocean floor (p. 35)
subduction
- process by which the ocean floor crust sinks beneath a deep-ocean trench and back into the mantle at a convergent plate boundary (p. 38)
rift valley

a deep valley that forms when two plates move apart (p. 45)
divergent boundary

a plate boundary where two plates move away from each other (p. 45)
convergent boundary

a plate boundary where two plates move toward each other (p. 46)
oceanic plates
- located in the lithosphere; a tectonic plate underneath the ocean that carries the ocean floor (p. 42)
continental plate
- a section of the lithosphere; a tectonic plate underneath the continent that carries the continents (p. 42)

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holtreading

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Card Set

8th grade Earth Science

Description

earth's layers, divergent, convergent

Updated

2011-01-10T01:38:23Z

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