III. Plate Boundaries A. Transform B. Divergent C. Convergent

III.Plate Boundaries A. Transform Two plates slide past each other and transform surface features Two plates slide past each other and transform surface features ex. San Andreas Fault ex. San Andreas Fault

III.Plate Boundaries B. Divergent Two plates move away from each other Two plates move away from each other As they separate, magma rises to fill the gap As they separate, magma rises to fill the gap

III.Plate Boundaries B. Divergent Features: Features: Midoceanic ridge Midoceanic ridge Rift valley Rift valley Seafloor spreading Seafloor spreading Surtsey Island Surtsey Island Iceland’s Hot Springs Iceland’s Hot Springs

midoceanic ridge, sea floor spreading, rift valley

The Great Rift Valley in Eastern Africa

Surtsey Island, near Iceland…born in 1963

Now it has life...

Hot Springs in Iceland….Blue Lagoon

III.Plate Boundaries C. Convergent Two plates approach each other Two plates approach each other 1. Continental – Continental formed Himalayas

III.Plate Boundaries C. Convergent 2. Continental – Oceanic aka subduction zone oceanic crust dives below continental crust Trenches Trenches Mountains Mountains Volcanoes Volcanoes

III.Plate Boundaries C. Convergent 3. Oceanic – Oceanic trenches (Marianis and Challenger Deep) trenches (Marianis and Challenger Deep) Undersea Volcanoes, aka “seamount” Undersea Volcanoes, aka “seamount” Island Arcs Island Arcs

Undersea Volcanoes can form islands over many years of eruption Undersea Volcanoes can form islands over many years of eruption Mauna Loa and Kilauea are volcanoes on the island of Hawaii. They were once seamounts. Loihi is an undersea volcano off the southern coast of Hawaii…someday it will be an island

Hawaii was formed as a series of volcanoes