A volcano is a place (usually a mountain) A volcano is a place (usually a mountain) where magma reaches Earth’s surface.where magma reaches Earth’s surface.

Magma Chamber

Lava:

Vent: Crater:Opening in the volcano

Erupted magma

Pit at the top of the volcano

Lava:Lava: Molten rock that flows or oozes onto Earth’s Molten rock that flows or oozes onto Earth’s surface. surface.

Lahars:Lahars: Flows of mud, rock and water. Flows of mud, rock and water.

Pyroclastic flows:Pyroclastic flows: Hot Hot avalanches of ash and gas.avalanches of ash and gas.

Tephra:Tephra: Gases and fragments of rock and lava Gases and fragments of rock and lava sent high into the sky.sent high into the sky.

1. Cinder cone volcano:1. Cinder cone volcano:• cone-shaped with steep sides.cone-shaped with steep sides.• made from explosive eruptions of small made from explosive eruptions of small

particles of rock (cinders).particles of rock (cinders).• a loose pile of volcanic rock fragments.a loose pile of volcanic rock fragments.

Examples:Examples:• Paricutin in Mexico.Paricutin in Mexico.• Wizard Island in Crater Lake.Wizard Island in Crater Lake.

2. Shield volcano: 2. Shield volcano: • broad, flat dome-shaped volcanoes.broad, flat dome-shaped volcanoes.• built up of many slow thin layers of hardened built up of many slow thin layers of hardened

lava. lava. • silica-poor lava (thin & runny).silica-poor lava (thin & runny).

Examples: Examples: • Mauna Loa and Kilauea in Hawaii Mauna Loa and Kilauea in Hawaii

- the world’s largest shield volcano is Mauna Loa (10.5 - the world’s largest shield volcano is Mauna Loa (10.5 miles high).miles high).

3. Composite volcano: 3. Composite volcano: • usually cone-shaped. usually cone-shaped. • built up of layers of hardened lava and rock built up of layers of hardened lava and rock

fragments.fragments.• silica-rich lava (thick & pasty)silica-rich lava (thick & pasty)

Examples:Examples:• Mt. St. HelensMt. St. Helens• Mt. RainierMt. Rainier

Active volcano:Active volcano: A volcano which has erupted recently A volcano which has erupted recently or might erupt soon.or might erupt soon.

Dormant volcano:Dormant volcano: A volcano that has been quiet for a long A volcano that has been quiet for a long time, but still has signs it may erupt again.time, but still has signs it may erupt again.

Extinct volcano:Extinct volcano: A volcano that has not A volcano that has not erupted for thousands of years and cannot erupted for thousands of years and cannot erupt again.erupt again.

Read section 8.2 Read section 8.2 [page 262 or 86B] [page 262 or 86B] and and record additional notes to your foldable.record additional notes to your foldable.

Use your foldable on tomorrow’s quiz.Use your foldable on tomorrow’s quiz.