III. Layers of the Earth

III. Layers of the Earth

IV. Plate Boundaries

IV. Plate BoundariesA. Plates move by convection currents in mantle

Plate movement

B. Convergent Plate Boundary

PLATES TYPEWhat

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 mountains Himalayas

Ocean-Ocean (Subduction)

Ocean-Continent (Subduction)

Continent-Continent (Collision)

C. Divergent Plate Boundary

PLATES TYPE What Happens?

Resulting Features Location

Oceanic + Oceanic

Spreading Center

New young crust rises up to fill in gap, which

also fills with H2O

Mid-Ocean Ridges

Mid Atlantic Ridge, Iceland

Continent + Continent

Spreading Center

Bodies of water Red Sea

D. Transform Fault Boundary

PLATES What 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 SpotsA. Caused by rising

mantle plumesB. Create Volcanoes and

Volcanic Islands1. Hawaiian Islands2. Yellowstone National

Park 3. Azores4. Galapagos

Hawaiian Islands

VI. Hot Spots