Download Earth`s Moving Plates

Earth’s Moving
Plates
Theory of Plate Tectonics
 Links
the ideas of continental drift
and ocean floor spreading and
explains how the earth has
evolved over time.
 Explains the formation,
movement, collisions and
destruction of the Earth’s crust.
Lithosphere
 Top
most solid part of the earth
Lithospheric Plate
 Moving
irregular shaped slabs
that fit together to make the
earths crust.
 There are 7 major plates which
are different sizes and move at
different speeds.
Plate Motion
 Convection
currents move
plates.
 Caused by differences in
temperature.
The Earth’s Spreading
Ocean Floor
Mid-ocean Ridges
 Under
water mountains and
valleys.
Trenches
V
shaped valleys at the bottom
of oceans, which are usually
found on the edges of
continents and islands.
 Deepest part of the ocean
Ocean Floor Spreading
 Lava
erupts at rift valleys and
hardens to form new ocean
floor.
 Explains how the continents
move.
Subduction
 Process
in which old crust
plunges back into the earth.
 Rocks are pushed deep into
trenches where they are
melted by the heat of the
earth. They recycle.
Evidence to Support Ocean
Floor Spreading
Rock
age- youngest rocks
are found near rift valleys
and oldest rocks are found
near trenches.
Evidence Cont…
Magnetic
Stripes- magnetic
rock line up with the poles
equally on both sides of the
mid-ocean ridge.