1. Plate Boundaries and Landforms that are created there
Plate Tectonics
Plate Boundaries and Landforms that are created there

2. Plate Tectonics Theory - Wegener
The earth is made up of rigid slabs of rock, or plates the move with respect to each other.
These plates “float” on the hot, semi-plastic mantle – in a balanced state known as “Isostasy.”
The Lithosphere is made of these plates and the upper most mantle.
The “plates” are like puzzle pieces

3. Evidence for Plate Tectonics
GPS – Global Positioning System
Satellites can measure the distances and speeds that the plates are moving.
Evidence of magnetic reversal in the rocks
Similar fossil evidence on different continents

4. Plate Boundaries
Divergent Boundaries
Where two plates are going away from each other
Forms the Mid Ocean Ridge if in the ocean
Forms Rift Valleys if over a continent

5. Plate Boundaries
Transform Boundaries
Where two plated slide past each other
San Andreas Fault is the most famous.
Stress builds and then earthquakes happen when the pressure is released.

6. Plate Boundaries Convergent Boundaries
When two plates collide with each other.
The denser one can slide under the other at Subduction Zones which created Ocean trenches.
Volcanoes usually line the edges of this boundary
Continent vs. Ocean = Subduction Zone
Ocean vs. Ocean = Volcanic Islands
Continent vs. continent = Mountain Ranges Himalayas

7. Plate Motion
Convections Currents
The circulation of material caused by differences in temperatures.
Warm rises and cold sinks

8. Plate Motion
Basal Drag – Asthenosphere pulls the lithosphere like a conveyor belt
Ridge Push – Rising mantle pushed the plates away from each other with gravity
Slab Pull – Sinking plates at a subduction zone pulls the plate downward
Still not sure which one has a greater effect on the movement of the continents

9. Plate Motion

10. Up and Down Motion
Subsidence – Downward vertical motion from force of ice on top of the continents
Uplift – upward vertical motion which happens when the ice melts and the continent rises

11. Horizontal Motion
Three type of stress:
Compression – Squeezing together – equal in the middle
Tension – Pulling apart equal in the middle
Shear - top in one direction bottom in the other