Volcano-Tectonic Processes

Foreword
Preface
Acknowledgements
Contents
About the Author
1 Volcanoes and Volcanic Activity
1.1 Introduction
1.2 The Volcano Factory
1.3 Distribution of Volcanoes and Origin of Magmas
1.4 Composition of Magmas
1.5 Physical Properties of Melts and Magmas
1.6 Types of Volcanic Edifices
1.7 Volcanic Activity
1.8 Effusive Eruptions and Their Products
1.9 Explosive Eruptions and Their Products
1.10 Volcanic Hazard and Risk
1.11 What is Volcano-Tectonics?
1.12 Summary
1.13 Main Symbols Used
References
2 Crustal Deformation
2.1 Introduction
2.2 Stress
2.3 Deformation
2.4 Rheology of Rocks
2.4.1 Elastic Deformation
2.4.2 Plastic Deformation
2.4.3 Viscous Deformation
2.4.4 Combined Deformation Models
2.4.5 The Role of the Boundary Conditions
2.4.6 Rheology of the Crust and Magma
2.5 Brittle Deformation
2.5.1 Extension Fractures
2.5.2 Shear Fractures
2.6 Faults
2.7 Tectonic Regimes
2.7.1 Extensional Tectonics
2.7.2 Contractional Tectonics
2.7.3 Strike-Slip Tectonics
2.8 Summary
2.9 Main Symbols Used
References
3 The Rise of Magma Through the Crust
3.1 Introduction
3.2 Magmatic Diapirs
3.2.1 Diapir Initiation
3.2.2 Diapir Rise
3.2.3 Diapir Emplacement
3.2.4 Diapirism and Stoping
3.2.5 Limitations of Diapirism as a Mechanism for Magma Transport
3.3 Magma-Filled Fractures
3.4 Dike Propagation
3.4.1 Solid Mechanics
3.4.2 Fluid Mechanics
3.4.3 Thermal Constrains
3.4.4 Seismicity Constraints
3.5 Dike Arrest
3.6 Summary
3.7 Main Symbols Used
References
4 Magma Emplacement and Accumulation: From Sills to Magma Chambers
4.1 Introduction
4.2 General Features
4.3 Sills
4.3.1 Overview
4.3.2 Emplacement Conditions
4.4 Laccoliths, Bysmaliths and Lopoliths
4.4.1 Overview
4.4.2 Emplacement Conditions
4.5 Plutons
4.5.1 Overview
4.5.2 Tectonically-Assisted Plutons
4.5.3 Magma-Induced Plutons
4.6 Magma chambers and magma reservoirs
4.6.1 Overview
4.6.2 Development Conditions
4.6.3 Magma Chambers Attracting and Nucleating Dikes
4.7 The Plutonic-Volcanic Link
4.8 Summary
4.9 Main Symbols Used
References
5 Calderas
5.1 Introduction
5.2 General Features of Calderas
5.3 Structure and Evolution
5.4 Classification
5.5 Relationships to Regional Tectonics
5.6 Resurgence
5.7 Caldera Unrest
5.8 Long- Versus Short-Term Deformation
5.9 Magma Transfer and Eruptions
5.10 Lessons from Active Calderas
5.10.1 Sierra Negra
5.10.2 Rabaul
5.10.3 Recent Caldera Collapses
5.11 Summary
5.12 Main Symbols Used
References
6 Volcano Flank Instability and Collapse
6.1 Introduction
6.2 General Features
6.3 Anatomy of an Unstable Flank
6.4 Causes of Flank Instability and Collapse
6.4.1 Magma Emplacement (Dikes and Viscous Intrusions)
6.4.2 Hydrothermal Alteration
6.4.3 Excess Pore Pressures
6.4.4 Weak Layers and Basement (Volcano Spreading)
6.4.5 Fault Activation and Earthquakes
6.4.6 Weather and Climate
6.5 Analysis of Flank Instability
6.6 Sector Collapse and Eruptive Activity
6.7 Multi-hazards Related to Flank Instability and Collapse
6.8 Lessons from Unstable Volcanoes
6.8.1 Mount Etna
6.8.2 Mount St. Helens
6.8.3 Augustine
6.9 Summary
6.10 Main Symbols Used
References
7 Shallow Magma Transfer
7.1 Introduction
7.2 Overview
7.3 Regional Dikes
7.4 Magma Transfer Through Sills
7.5 Circumferential Intrusions
7.5.1 Circumferential Eruptive Fissures
7.5.2 Cone Sheets
7.5.3 Ring-Dikes
7.6 Radial Dikes
7.6.1 Radial Dikes in Conical Volcanic Edifices
7.6.2 Radial Dikes in Conical Edifices with Sector Collapse
7.6.3 Radial Dikes in Elongated Edifices
7.7 Dikes Reaching the Surface
7.8 Summary
7.9 Main Symbols Used
References
8 Volcano Monitoring
8.1 Introduction
8.2 General Features
8.3 Deformation Monitoring
8.3.1 Deformation Monitoring Techniques
8.3.2 Deformation Source Models
8.3.3 Deformation Forecasting Potential
8.4 Geophysical Monitoring
8.4.1 Monitoring Volcano Seismicity
8.4.2 Monitoring Volcano Gravity
8.5 Geochemical Monitoring
8.6 Summary
8.7 Main Symbols Used
References
9 Unrest and Eruption Forecasting
9.1 Introduction
9.2 General Features
9.3 Unrest Triggers
9.3.1 Magmatic Trigger
9.3.2 Hydrothermal Trigger
9.3.3 Seismic Trigger
9.4 Understanding Unrest
9.5 Assessing Volcanic Hazard and Forecasting Eruptions
9.6 Deterministic Forecasting
9.7 Probabilistic Forecasting
9.7.1 Long-Term Forecasting
9.7.2 Short-Term Forecasting
9.8 Summary
9.9 Main Symbols Used
References
10 Volcanoes and Plate Tectonics
10.1 Introduction
10.2 The Plate Tectonics Frame
10.3 Magmatic Processes Along Divergent Plate Boundaries
10.4 Magmatic Processes Along Convergent Plate Boundaries
10.5 Magmatic Processes at Hot Spots
10.6 Polygenic and Monogenic Volcanism
10.7 Magma Versus Regional Tectonics
10.8 Summary
10.9 Main Symbols Used
References
11 Volcanoes at Divergent Plate Boundaries
11.1 Introduction
11.2 Continental Rifts: The East African Rift System
11.2.1 The Main Ethiopian Rift
11.3 Transitional Rifts: Afar
11.4 Oceanic Rifts
11.4.1 Ultraslow Ridges: The Red Sea and the Southwest Indian Ridge
11.4.2 Slow Ridges: The Icelandic Ridge
11.4.3 Fast and Ultrafast Ridges: The East Pacific Rise
11.5 A General Model for Divergent Plate Boundaries
11.6 Summary
11.7 Main Symbols Used
References
12 Volcanoes Along Convergent Plate Boundaries
12.1 Introduction
12.2 Extensional Arcs
12.2.1 Cascade Arc
12.2.2 Taupo Volcanic Zone of New Zealand
12.2.3 Tyrrhenian Margin of Central Italy
12.3 Strike-Slip Arcs
12.3.1 The South Andean Volcanic Zone
12.3.2 Sumatra, Indonesia
12.4 Contractional Arcs
12.4.1 Northeast Honshu, Japan
12.4.2 The Central Andes
12.5 A Synthetic Model for Convergent Plate Boundaries
12.6 Summary
References
13 Hot Spots
13.1 Introduction
13.2 Hawaii Hot Spot
13.3 Galapagos Hot Spot
13.4 Easter Island Hot Spot
13.5 Reunion Hot Spot
13.6 Canary Islands Hot Spot
13.7 Azores Hot Spot
13.8 Yellowstone Hot Spot
13.9 Tibesti Hot Spot
13.10 Comparing Hot Spot Volcanoes
13.11 Summary
References
Index