III. Layers of the Earth

IV. Plate Boundaries

A.Plates move by convection currents in mantle Plate movement

B. Convergent Plate Boundary PLATESTYPE What Happens? Resulting Features Location Oceanic + Oceanic Subduction zone More dense subducts volcanic islands Aleutian Islands, Philippines Ocean + Continent Subduction zone Oceanic subducts volcanic mtns Andes, Cascades Continent + Continent Collision Plates push up mountainsHimalayas

Ocean-Ocean (Subduction)

Ocean-Continent (Subduction)

Continent-Continent (Collision)

C. Divergent Plate Boundary PLATESTYPE What Happens? Resulting Features Location Oceanic + Oceanic Spreading Center New young crust rises up to fill in gap, which also fills with H 2 O Mid-Ocean Ridges Mid Atlantic Ridge, Iceland Continent + Continent Spreading Center Bodies of water Red Sea

D. Transform Fault Boundary PLATESWhat Happens? Resulting Features Location Ocean + Ocean Plates slide past each other Fault Lines, Earthquakes, Tsunami Indian Ocean Tsunami Continent + Continent Plates slide past each other Fault Lines, Earthquakes San Andreas Fault

V. Seafloor Spreading Oceanic crust is only about 200 million years old, where continental crust is about 3.5 billion years old! Oceanic crust is constantly being made and subducted.

V. Seafloor Spreading OLD YOUNG

VI. Hot Spots A.Caused by rising mantle plumes B.Create Volcanoes and Volcanic Islands 1.Hawaiian Islands 2.Yellowstone National Park 3.Azores 4.Galapagos Hawaiian Islands

VI. Hot Spots