Volcanology

  1. Eruptive Processes and Styles
    1. Drivers of Eruptions
      1. Magma Buoyancy
        1. Density Contrasts
          1. Buoyancy Forces
          2. Gas Exsolution and Expansion
            1. Volatile Saturation
              1. Bubble Nucleation
                1. Gas Expansion
                2. Magma Recharge
                  1. Fresh Magma Injection
                    1. Pressure Increase
                    2. Overpressure and Fracturing
                      1. Critical Pressure
                        1. Conduit Opening
                          1. Dike Propagation
                          2. External Triggers
                            1. Earthquakes
                              1. Rainfall
                                1. Tidal Forces
                              2. Classification of Eruption Styles
                                1. Effusive Eruptions
                                  1. Characteristics
                                    1. Low Gas Content
                                      1. Low Viscosity
                                        1. Gentle Outpouring
                                        2. Associated Landforms
                                          1. Lava Flows
                                            1. Shield Volcanoes
                                          2. Explosive Eruptions
                                            1. Characteristics
                                              1. High Gas Content
                                                1. High Viscosity
                                                  1. Violent Fragmentation
                                                  2. Associated Landforms
                                                    1. Pyroclastic Deposits
                                                      1. Stratovolcanoes
                                                  3. Specific Eruption Types
                                                    1. Hawaiian
                                                      1. Features and Hazards
                                                        1. Lava Fountains
                                                          1. Lava Flows
                                                            1. Minimal Explosive Activity
                                                          2. Strombolian
                                                            1. Features and Hazards
                                                              1. Intermittent Explosions
                                                                1. Scoria and Bombs
                                                                  1. Moderate Hazards
                                                                2. Vulcanian
                                                                  1. Features and Hazards
                                                                    1. Short-Duration Explosions
                                                                      1. Ash Columns
                                                                        1. Ballistic Projectiles
                                                                      2. Peléan
                                                                        1. Features and Hazards
                                                                          1. Pyroclastic Flows
                                                                            1. Dome Collapse
                                                                              1. High Lethality
                                                                            2. Plinian and Ultra-Plinian
                                                                              1. Features and Hazards
                                                                                1. High Eruption Columns
                                                                                  1. Widespread Ashfall
                                                                                    1. Pyroclastic Flows
                                                                                      1. Regional Impact
                                                                                    2. Surtseyan (Phreatomagmatic)
                                                                                      1. Features and Hazards
                                                                                        1. Magma-Water Interaction
                                                                                          1. Steam-Driven Explosions
                                                                                            1. Base Surges
                                                                                          2. Phreatic (Steam-Blast)
                                                                                            1. Features and Hazards
                                                                                              1. No New Magma
                                                                                                1. Hydrothermal Explosions
                                                                                                  1. Localized Impact
                                                                                              2. The Volcanic Explosivity Index (VEI)
                                                                                                1. Scale and Criteria
                                                                                                  1. Eruption Column Height
                                                                                                    1. Tephra Volume
                                                                                                      1. Qualitative Descriptions
                                                                                                      2. Examples of VEI Ratings
                                                                                                        1. VEI 0-2 Examples
                                                                                                          1. VEI 3-5 Examples
                                                                                                            1. VEI 6-8 Examples
                                                                                                            2. Limitations of VEI

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                                                                                                          4. Volcanic Structures and Landforms

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                                                                                                          6. Volcanic Products and Deposits