Volcanoes - outline

VOLCANOES (Chapter 12) - Lecture Outline

Last updated: 03/08/07

Basic considerations

Volcanoes are buoyant magma

	reveal information about the mantle and crust
	bring gases to the surface

1. Types of volcanic deposits

Lava flows

Rhyolitic lavas

Basaltic lavas

	Multiple flows (plateaus)
	Classification: pahoehoe vs. aa
	Lava tubes
	Columnar joints
	Pillow lavas

Pyroclastic eruptions and deposits

Ash

Volcanic bombs

Volcanic breccia

Pyroclastic flows

Pyroclastic deposits

	Volcanic tuff
	Welded tuff
	Volcanic breccia
	Lahar

Geysers and fumaroles

2. Styles of eruptions and landforms

Central vent eruptions

	Lava eruptions - shield volcano
	Lava eruptions - lava dome
	Pyroclastic eruptions - cinder cone
	Caldera
	Diatremes

Fissure eruptions

	Flood basalts
	Ash flow deposits

3. Global pattern of volcanism

Most volcanoes near plate boundaries

	Compressional boundaries
	Extensional boudaries
	Exception: intraplate

4. Volcanic hazards

Hazards associated with volcanic eruptions

Super-volcano eruptions

Pyroclastic flows and lateral blasts

Volcanic ash and hot poisonous gases

Lahars

Tsunamis

Gases

Ash - air traffic

Lava flows

5. Potentially hazardous volcanoes

	Knowledge of hazards
	Prediction and monitoring of hazards