Volcano Types and Volcanic Eruptions

1. Why Volcanoes Erupt: The F of expanding gas builds and pushes magma through the vent

2. Major Factors in Eruptions: a. The amount of trapped gas – CO 2 and Sulfur b. Silica Content – The more silica, the more explosive

C. Common Volcano Products – Ash: Fine rock particles, less than 1/10 of an inch

C. Common Volcano Products – Cinder Rock pieces at least 2.5 inches to many feet

C. Common Volcano Products Pyroclastic Flow: – Mix of hot ash, bombs, gas, pumice and glass that can travel up to 100 miles per hour.

3. Common Volcano Types Shield Volcano – Structure – Composition Layers of built up lava – Eruption Type Quiet – Lava Type Pahoehoe – Hazards Burning land, ash covered – Example Hawaiian Islands

3. Common Volcano Types Cinder Cone – Structure – Composition Layers of ash, cinders and bombs – Eruption Type Explosive – Lava Type Aa – Hazards Deadly gasses, landslides, avalanche, pyroclastic flow – Example: Paricutin, Mexico

3. Common Volcano Types Composite – Structure – Composition Alternate lava and ash – Eruption Type Alternate Quiet and explosive – Lava Type Pahoehoe and Aa – Hazards Alternate – Example: Mt. St. Helens

4. Volcanic Activity a. Common Volcano Locations

b. Volcanic Eruption simulation explorer/ explorer/

4. Volcanic Activity b. Life Cycle: – Active A volcano likely to erupt soon – Ex. Mt. Fuji and Mt. St. Helens – Dormant A Volcano that may erupt in the future – Mt. Hood, Oregon and Mt. Kilimanjaro, Africa – Extinct: A volcano unlikely to erupt (10,000 years) – Mt. Buninyong, Australia