PLATE TECTONICS

Definition of plate tectonics.
A theory explaining the structure of the earth's crust and many associated phenomena as resulting from the interaction of rigid lithospheric plates that move slowly over the underlying mantle.

Cause of plate movement #1.
Convection currents-Force that move tectonic plates

Cause of plate movement #2.
Slab pull-the portion of motion of a tectonic plate that can be accounted for by its subduction.

Cause of plate movement #3.
Ridge pull- or sliding plate force is a proposed mechanism for plate motion in plate tectonics.

DIVERGENT BOUNDARY

• A plate boundary where two plates move away from each other
• Mid ocean ridges
• Rift Valley

Land form resulting from a divergent plate boundary(land)

Land form resulting from a divergent plate boundary (sea)

CONVERGENT BOUNDARY

• A plate boundary where two plates move toward each other.
• Trenches
• Mountains

Resulting land form from a convergent plate boundary (ocean vs continent)

Resulting land form from a convergent plate boundary (continent vs continent)

Resulting land form from a convergent plate boundary.
(ocean vs ocean)

Subduction zone/
The process by which collision of the earth's crustal plates results in one plate's being drawn down or overridden by another.

Deep ocean trench/
hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor.

One example of a deep ocean trench is the Marianas Trench

Transform boundary/known as conservative plate boundary since these faults neither create nor destroy lithosphere

Resulting land form from a transform plate boundary

One example of a transform boundary is the San Andreas fault