Plate Tectonics

who came up with continental drift?

alfred wegner

what was his original evidence for it?

all of the continents fit together

why wasnt it accepted?

he could not show how they moved

what is seafloor spreading?

the formation of new areas which occurs from a magma upwelling

what are three pieces of evidence to support the theory?

the mid-ocean ridge, echo-sounding, rock ages, and rocks that are close to the ridge are younger

layers of the earth

inner core, outer core, mantle and crust

inner core

\-high temperatures

\-high pressures

\-mainly iron

\-rotates

outer core

\-liquid

\-metal

\-iron

\-nickel

\-very dense

mantle

\-the layer between the core and crust

\-the largest layer of the earth

\-composed of silicates (Sio2)

\-divided into upper and lower

asthenosphere

\-plastic like

\-uppermost mantle

\-able to flow

plate boundaries

transform, convergent, and divergent

convection

the process of fluid cycling based on changes in temperature

conduction

direct contact

radiation

non-direct contact

subduction

oceanic and continental or oceanic and oceanic

lithosphere

crust and upper mantle

laurentia

craton forms the core of North America

schist

really hard rock

deep sea trench

made of subduction zones, convergent

mid-ocean ridge

oceanic and oceanic, divergent

rift valley

continental and continental, divergent

convergent plates make

mountains, volcanoes, or subduction zones

transform plates make

fault line

where are subduction zones found?

the pacific ocean

iceland

the only place with above water mid-atlantic ridge and the only place that sits on two plates

which heat transfer drives the earths crust

convection