1. EARTH SCIENCE JOURNAL DATE:
Examine the diagram above. Describe the movement of the plates and the processes that are occurring.
What type of plate boundary is this?

2. Mechanisms of Plate Motion
MANTLE CONVECTION CURRENTS
Mantle rock is so warm that it churns slowly around like very very thick syrup boiling on the stove!

3. Mechanisms of Plate Motion
MANTLE PLUMES AND HOT SPOTS
Hot spots are created by mantle plumes.
Mantle plumes are hot currents that rise all the way from the core through the mantle.
Mantle plumes can come up under the crust and burn their way through to create hot spot volcanoes.

4. Mechanisms of Plate Motion
HOT SPOTS stay in the same place while tectonic plates move over them.
Each time the plate moves the hot spot creates a new volcano. (Hawaiian Islands)

5. Hot Spots track plate movement! Click here to see this in motion

6. Shifting Poles Paleomagnetism
The magnetic poles typically wander around slowly.
But every so often flip completely, reversing the magnetic polarity of the planet.

7. More Evidence of Plate Tectonics
The experts are reasonably sure the earth's magnetic field is a result of movement in the planet's liquid iron and nickel core.
As the iron-rich magma pushing up from beneath the plate boundary cools and spreads out, the mineral crystals align themselves with the magnetic field as it then exists.
The alternating stripes indicate field flip-flops over geological time.

8. The alternating stripes indicate field flip-flops over geological time.

9. Magnetic Reversals Record Sea-Floor spreading