8Th Grade Plate Tectonics Itasca Middle School, Tx

Front 1

tectonic plates

Back 1

the lithosphere is divided into huge pieces that move around on top of the asthenosphere.

Front 2

continental drift

Back 2

is the theory that continents can drift apart from one another and have done so in the past.

Front 3

sea-floor spreading

Back 3

the process by which new oceanic lithosphere forms at mid-ocean ridges

Front 4

plate tectonics

Back 4

is the theory that the lithosphere is divided into tectonic plates that move around on top of the asthenosphere.

Front 5

convergent boundary

Back 5

when two tectonic plates collide.

Front 6

divergent boundary

Back 6

when two tectonic plates separate.

Front 7

transform boundary

Back 7

when two tectonic plates slide past each other horizontally.

Front 8

stress

Back 8

the amount of force per unit area that is put on a rock.

Front 9

strain

Back 9

any change in a rock's shape or volume caused by stress.

Front 10

seismic waves

Back 10

the vibrations caused by earthqakes.

Front 11

Alfred Wegener

Back 11

in the early 1900s, developed the theory of continental drift.

Front 12

mid-ocean ridges

Back 12

are underwater mountain chains in Earth's ocean basins.

Front 13

Pangaea

Back 13

Greek for "all earth" this was a supercontinent in which all the continents combined together to form one single giant landmass.

Front 14

lithosphere

Back 14

is the cool, outermost layer of the Earth. It consists of the crust and rigid, uppermost part of the mantle. It is divided into huge pieces called tectonic plates which move around.

Front 15

asthenosphere

Back 15

is the solid, soft layer of the mantle below the lithosphere.

Front 16

mesosphere

Back 16

"middle sphere" is the solid lower part of the mantle below the asthenosphere.

Front 17

outer core

Back 17

is the outer shell of Earth's core.

Front 18

inner core

Back 18

is a sphere of solid iron and nickel