Book contents
- Frontmatter
- Contents
- Contributors
- Chapter 1 Introduction
- Chapter 2 Magma chamber dynamics and thermodynamics
- Chapter 3 The dynamics of dike propagation
- Chapter 4 Dynamics of magma ascent in the volcanic conduit
- Chapter 5 Lava flows
- Chapter 6 Unsteady explosive activity
- Chapter 7 Unsteady explosive activity
- Chapter 8 Sustained explosive activity
- Chapter 9 Modeling tephra sedimentation from volcanic plumes
- Chapter 10 Pyroclastic density currents
- Chapter 11 Magma–water interactions
- Chapter 12 Deep-sea eruptions
- Chapter 13 Volcano–ice interactions
- Chapter 14 Modeling lahar behavior and hazards
- Chapter 15 Introduction to quantitative volcano seismology
- Chapter 16 Volcano acoustics
- Chapter 17 Planetary volcanism
- Index
- Plate section
- References
Chapter 7 - Unsteady explosive activity
Vulcanian eruptions
Published online by Cambridge University Press: 05 March 2013
- Frontmatter
- Contents
- Contributors
- Chapter 1 Introduction
- Chapter 2 Magma chamber dynamics and thermodynamics
- Chapter 3 The dynamics of dike propagation
- Chapter 4 Dynamics of magma ascent in the volcanic conduit
- Chapter 5 Lava flows
- Chapter 6 Unsteady explosive activity
- Chapter 7 Unsteady explosive activity
- Chapter 8 Sustained explosive activity
- Chapter 9 Modeling tephra sedimentation from volcanic plumes
- Chapter 10 Pyroclastic density currents
- Chapter 11 Magma–water interactions
- Chapter 12 Deep-sea eruptions
- Chapter 13 Volcano–ice interactions
- Chapter 14 Modeling lahar behavior and hazards
- Chapter 15 Introduction to quantitative volcano seismology
- Chapter 16 Volcano acoustics
- Chapter 17 Planetary volcanism
- Index
- Plate section
- References
Summary
Overview
Vulcanian eruptions are named for the 1888–90 eruptions of Vulcano, Aeolian Islands, Italy (Mercalli, 1907), and are defined here as short-lived, discrete explosions resulting from sudden decompression of a volcanic conduit caused by disruption of a sealing plug or dome. Resulting eruptions characteristically last only seconds to minutes and may produce buoyant columns, pyroclastic density currents, or both. They may occur as single events or in a sequence of discrete explosions. The short duration and unsteady vent conditions of vulcanian eruptions make them distinct from sustained plinian or subplinian eruptions. Pre-eruption pressures can reach 10 MPa, vent velocities may approach 400 m s−1, eruption plumes typically rise to < 10 km, but in some cases may reach nearly 20 km, and the amount of magma erupted is typically < 1011 kg. This chapter reviews mechanisms associated with vulcanian eruptions and discusses several relevant conceptual and quantitative models. Topics include plug formation and disruption, magma fragmentation, calculation of vent flux, the production and propagation of shock waves, the dynamics of pyroclastic jets and plumes ascending from unsteady sources, and ballistic analysis. This chapter also addresses important questions regarding controls on the scale and duration of such short-lived explosions, as well as transitions in eruptive style.
- Type
- Chapter
- Information
- Modeling Volcanic ProcessesThe Physics and Mathematics of Volcanism, pp. 129 - 152Publisher: Cambridge University PressPrint publication year: 2013
References
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