TECTONIC PLATES

Continents and Oceans

Tectonic Plates

3 Types of Tectonic Plate Boundaries

Divergent Boundary spreads apart, or divides, making new ocean floor along mid ocean ridges.

Convergent Boundary comes together. Ocean crust sinks under continental crust forming a subduction zone, ocean trench, and volcanoes on the continent.

Transform Boundary plates slide past each other causing earthquakes.

Convection Currents in mantle cause tectonic plates to slide across asthenosphere.

Subduction Zone A special type of convergent boundary where

denser ocean crust sinks under the less dense continental crust.

Found all around edge of the Pacific Ocean Forms the “Ring of Fire” around the Pacific

Ocean, an area of many earthquakes and volcanoes.

As the ocean crust sinks under, water seeps in causing the melting of rock which produces magma that eventually erupts as volcanoes along the edge of the continent. An ocean trench forms.

Andes Mountains in South America are an example of this type of mountain range made from volcanoes.

Subduction Zones and Volcanoes

When continents collide…

A type of convergent boundary… When two continents of equal density

collide, neither sinks under the other. Instead, a folded mountain chain forms.

After Pangaea broke up, India slammed into Asia, producing the Himalaya Mountains.

Another example of a folded mountain chain that formed this way is the Appalachian Mountain Range in the eastern United States.

Continent to Continent Convergent Boundary

India Slams into Eurasian Plate

Himalaya Mountains Rise

Eurasian Plate

India

Himalaya Mountains along the convergent boundary

Transform Boundary

Sliding Past Each Other

As plates move past each other , they get “hung up” due to friction and bend the rock

Eventually, the bent rock will snap back into place

As this happens, a tremendous amount of energy is released

This causes an earthquake The San Andreas Fault in California is an

example of this type of plate boundary.