Download Plate Tectonics - Ms. Gravette and the Mad Scientists

Plate Tectonics
Write on RIGHT Side
What discoveries support continental drift?
In mid 1900s, scientists found
under-water mountain ranges
called mid-ocean ridges. This
discovery led to the Theory of
Plate Tectonics
Theory of Plate Tectonics
Describes why and how the
Earth’s surface changes
A Tectonic Plate is a large piece of
lithosphere that is floating on the
asthenosphere
The word “Tectonic” is Greek for
“builder”
Tectonic Plates build and shape our Earth
(mountains, earthquakes, volcanos, etc.)
Plates move at different speeds
and in different directions
Oceanic plates are more dense
than continental plates
Why do tectonic plates move?
Due to Mantle Convection– the rock
rises and falls due to changes in
density. The rock heats and rises,
then cools and sinks
Form along cracks in the crust
Youngest rock is closest to the
ridge, oldest rock is farthest
away
The sea-floor rock contains
magnetic patterns
Sea- Floor
Spreading
Explains the age and magnetic patterns of
sea-floor rocks
The process where molten rock inside the
Earth rises through the cracks in the
ridges, cools, and forms new oceanic crust
MidOcean
Ridges
forming
and SeaFloor
Spreading
https://www.youtube.com/watch?v=ryrXAGY1dmE
Copy the information and draw the picture
of convection taking place in the mantle
Reflection
(Left Side)