Today’s Agenda…

Bellringer: What are compression, tension, and shearing? Use your notes on Earth’s plates.

Quiz Notes on Volcanoes Homework

Volcanoes

Study Pack #5

Today’s Goals…

I can explain how different types of volcanoes form.

I can describe how a volcanic eruption occurs. I can describe the stages of a volcano.

What are volcanoes?

Weak spots in the crust where magma comes to surface, cools, and becomes cone-shaped layers of rock

Where are volcanoes located?

600 active volcanoes on land Many more beneath the sea Volcanoes occur in belts that extend across

continents and oceansRing of Fire formed by many volcanoes that circle the

Pacific Ocean

Ring Of Fire

Where are volcanoes located?

Volcanic belts are found along the plate boundariesMostly divergent plate boundaries or convergent plate

boundaries where subduction occurs Some volcanoes also occur at hot spots

An area where magma melts through the crust

Types of Volcanoes

Cinder-Cone Composite Shield

Cinder Cone

Steep, cone-shaped hill or mountain Lava piles up and hardens

Cinder Cone

Sunset Crater, Arizona

Composite

Form at convergent plate boundaries where one plate is pushed (or subducted) under another plate

Magma is forced up through many cracks in the crust

Sometimes explosive

Composite

Mount St. Helens, Washington

Shield

Often form underwater at divergent plate boundaries

Can also form over hot spotsLead to the formation of the Hawaiian Islands

Shield

Kilauea, Hawaii

Inside a Volcano

Page 302 Magma flows from the magma chamber up the

pipe Magma flows out of the vents and becomes lava Lava often collects in the crater and then flows

down the slope Lava hardens to form rock (igneous rock)

Stages of Volcanoes

Active – a volcano that is erupting or may erupt in the future

Dormant – a volcano that is “sleeping” but may erupt in the future

Extinct – a “dead” volcano that is unlikely to erupt again

Homework Journey Through a Volcano Writing