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• Earthquake notes• 5-2 Homework

Volcanoes and Plate Tectonics

Section 9-2

What is a volcano?

• A weak spot in the crust where magma comes to the surface.

• Magma at surface = lava

Earth’s Active Volcanoes

Volcanoes at Divergent Boundaries

• Volcanoes form along the mid-ocean ridge, as lava escapes from cracks in the ocean’s floor.

Volcanoes at Convergent Boundaries

• Volcanoes often occur near plate boundaries as a result of subduction.

Volcanoes at Convergent Boundaries

• Island Arcs occur when 2 pieces of oceanic crust collide.

Hot Spot Volcanoes

• Super hot areas of the mantle melt through the crust to form Hot Spot volcanoes.

Hot Spot Volcanoes

Hawaii

Hot Spot Volcanoes

Yellowstone

Let’s Review!

• What is a volcano?• What is lava?• Why do volcanoes form at

divergent boundaries?• Why do volcanoes form at

convergent boundaries?• Why do volcanoes form at hot

spots?

Homework

•Read 6-1

•6-1 R/R due Friday