Divergent Plate Boundaries Divergent Plate Boundary Continental Crust

Divergent Plate Boundaries

Divergent Plate Boundary Continental Crust was once whole Over time the crust started spreading apart to create a Rift Valley. Ocean fills in The Ocean floor keeps spreading open

Divergent Plate Boundaries As plates move away from the ridge, the gaps are filled with molten rock that oozes up from the hot mantle. This adds new crust between the diverging plates.

Iceland is located on the Mid-Atlantic Ridge

Eyjafjallajokull volcano, Iceland The volcano had been dormant for 200 years. Before 2010

Eyjafjallajokull volcano, Iceland After 2010

Divergent Convergent Transform

Three types of convergent boundaries: Oceanic - Continental Oceanic - Oceanic Continental - Continental

Oceanic - Continental The plate which descends into the Mantle melts and turns into magma. This magma then rises back up to the surface.

The volcanic Andes Mountains were formed by oceanic-continental convergence, when the Nazca plate melted as it plunged beneath the continent of South America.

The Cascade Mountain Range, in western U. S. , is a volcanic mountain range that was formed as a result of oceanic-continental convergence. Eruption of Mount St. Helens in 1980

Oceanic – Continental Oceanic - Oceanic Continental - Continental

Oceanic - Oceanic Convergence When two oceanic plates converge, one subducts or descends beneath the other initiating volcanic activity (similar to the oceanic continental case), but the volcanoes form on the ocean floor rather than on continents.

Examples of island arcs are the island chains of the western Pacific Ocean, such as Japan. In the case of Japan, volcanic islands are being created by the collision of the Pacific plate with the Eurasian plate. The Pacific plate being subducted beneath the Eurasian plate.

Oceanic – Continental Forms Volcanic Arcs Oceanic – Oceanic Volcanoes form on the Ocean floor Continental – Continental Mountains form

Continental - Continental Convergence Mountains form from the collision of 2 continental plates.

India Colliding with Asia

Hot Spots Volcanoes not formed at Plate Boundaries

Hawaii- Hot Spot

World-Wide Hot Spot

Plate Tectonics