Plate Boundaries Convergent Boundaries Divergent Boundaries Transform Boundaries

Inside the Earth: The Earth's Core The Earth's core is a ball of nickel and iron. Its temperature is 4, 000 to 9, 000 degrees F The Earth's Mantle The mantle extends from 50 miles to a depth of 1, 750 miles beneath the Earth's surface. The temperature of the mantle is about 1, 600°F near the top.

Convection Currents: �Mantle Rock in the mantle is very hot , and able to flow. It flows upward, cools and descends toward the core. This circular motion is called convection.

Convection currents transfer heat from the core to the surface.

Tectonic Plates The Earth's crust and rigid upper mantle are broken into eight enormous slabs called tectonic plates. There also seven small tectonic plates.

Tectonic Plates float, similar to the way wood blocks float on water because they are less dense, the Plates float on the much denser mantle.

The plates are pulled apart from convection currents at divergent boundaries.

The plates are pushed together from convection currents at convergent boundaries. The area where the plates come together is called a subduction zone.

Convergent Boundaries can be continental / continental, oceanic / continental, or oceanic / oceanic. In each case different kinds of mountains are formed.

Continental / Continental Plate Boundary

Oceanic / Continental Plate Boundary

Subduction Zone at a Convergent Boundary

Oceanic/ Oceanic collisions Creates Volcanic Arcs The Pacific Plate is also referred to as the “Ring of Fire”

At a Transform Boundary the plates slide past each other in opposite directions, these are where faults form. An example of this is the San Andreas Fault.