Fundamentals of Physical Volcanology

The world’s leading student text on physical volcanology offers an unmatched introduction to the field In the revised second edition of Fundamentals of Physical Volcanology, the authors provide a comprehensive introduction to the processes that control when and how volcanoes erupt. Understanding these processes involves bringing together ideas from a number of disciplines, including branches of geology, such as petrology and geochemistry, and aspects of physics, such as fluid dynamics and thermodynamics. With the help of new and improved illustrations, this new edition explains eruption types and mechanisms, subsurface processes, volcanic eruption products, and how volcanoes affect their surrounding environment. Readers will also find: Quantitative treatment of physical volcanological processes A review of the historical development of volcanology Examples of current research trends and topics in volcanology Perfect for undergraduate earth sciences students and graduate students starting research programs in volcanology, Fundamentals of Physical Volcanology will also earn a place in the libraries of researchers in related fields seeking an accessible introduction to the principles of physical volcanology.

Table of Contents:
Preface xiii Acknowledgments xv Glossary xvii 1 Volcanic Systems 1 1.1 Introduction 1 1.2 Styles of Volcanic Eruptions 1 1.2.1 Effusive Eruptions 2 1.2.2 Hawaiian-Style Eruptions 3 1.2.3 Flood Basalt Eruptions 4 1.2.4 Plinian Eruptions 5 1.2.5 Ignimbrite-Forming Eruptions 6 1.2.6 Strombolian Eruptions 7 1.2.7 Vulcanian Eruptions 9 1.2.8 Hydromagmatic Eruptions 10 1.2.8.1 Deep Marine Environments 10 1.2.8.2 Lava Flows Entering Water 10 1.2.8.3 Shallow Marine and Crater Lake Eruptions 11 1.2.8.4 Subglacial Eruptions 12 1.2.8.5 Interactions with Groundwater 13 1.2.9 Diatreme-Forming Eruptions 13 1.3 Volcanic Systems 14 1.4 The Structure and Aims of This Book 16 1.5 Further Reading 16 1.6 Questions to Think About 17 2 Magma Generation and Segregation 19 2.1 Introduction 19 2.2 Rock-Melting Mechanisms 19 2.3 Volcanism and Plate Tectonics 20 2.3.1 Tectonic Settings, Melting Processes, and Magma Composition 23 2.3.1.1 Mid-Ocean Ridges and Oceanic Intraplate Settings 23 2.3.1.2 Continental Intraplate Settings 25 2.3.1.3 Subduction Zones – Island Arcs and Continental Arcs 25 2.4 Melting and Melt Segregation in the Mantle 27 2.4.1 Nature of the Mantle 27 2.4.2 Onset of Mantle Melting 28 2.4.3 Melt Migration 29 2.5 Summary 31 2.6 Further Reading 31 2.7 Questions to Think About 32 3 Magma Migration 33 3.1 Introduction 33 3.2 Diapiric rise of Melt 33 3.3 The Change From Diapir Rise to Dike Formation 34 3.4 Dike Propagation 35 3.5 Trapping of Dikes 37 3.6 Consequences of Dike Trapping 41 3.7 Summary 42 3.8 Further Reading 44 3.9 Questions to Think About 44 4 Magma Storage 45 4.1 Introduction 45 4.2 Evidence for Magma Storage Within the Crust 45 4.2.1 Structural Evidence Provided by Calderas 45 4.2.2 Petrological Evidence in Lava Flows 46 4.2.3 Geophysical Evidence 48 4.2.3.1 Seismic Techniques 48 4.2.3.2 Gravity and Magnetotelluric Techniques 49 4.2.3.3 Deformation Techniques 51 4.2.4 Geological Evidence From Exposed Intrusions 53 4.3 Formation and Growth of Magma Reservoirs 55 4.4 Magma Reservoirs and Their Impact on Volcanic Systems 62 4.4.1 Fractionation in Magma Reservoirs 62 4.4.2 Regulation of Eruption Frequency and Magnitude 63 4.4.3 Volatiles and Chamber Failure 65 4.5 Summary 66 4.6 Further Reading 67 4.7 Questions to Think About 67 5 The Role of Volatiles 69 5.1 Introduction 69 5.2 Volatiles in Magma 69 5.3 The Solubility of Volatiles in Magma 70 5.4 Bubble Nucleation 73 5.5 Bubble Growth 74 5.5.1 Growth by Diffusion 74 5.5.2 Growth by Decompression 74 5.5.3 Bubble Coalescence 75 5.6 Influence of Volatiles on Magma Dynamics 78 5.7 Magma Fragmentation and the Influence of Volatiles on Eruption Styles 79 5.8 Summary 81 5.9 Further Reading 82 5.10 Questions to Think About 82 6 Steady Explosive Eruptions 83 6.1 Introduction 83 6.2 Influence of Gas Bubbles Prior to Magma Fragmentation 83 6.3 Acceleration of the Gas–Magma Mixture 84 6.4 Controls on Exit Velocity 86 6.4.1 Magmatic Gas Content and Exit Velocity 86 6.4.2 Dike Shape, Vent Geometry, and Exit Velocity 87 6.5 Eruption Plumes in Steady Eruptions 88 6.5.1 Plume Rise 89 6.5.2 Controls on Plume Height 91 6.6 Fallout of Clasts from Eruption Plumes 91 6.6.1 Rise of Clasts in an Eruption Plume 91 6.6.2 Fallout of Clasts from Eruption Plumes 93 6.7 Unstable Eruption Columns 93 6.7.1 Plume Density and Column Stability 94 6.7.2 Causes of Column Instability 94 6.8 Summary 96 6.9 Further Reading 97 6.10 Questions to Think About 98 7 Transient Volcanic Eruptions 99 7.1 Introduction 99 7.2 Magmatic Explosions 99 7.2.1 Modeling Transient Magmatic Explosions 100 7.2.1.1 Relating Vent Pressures to Eruption Velocities 100 7.2.1.2 Predicting the Range of Ballistic Clasts 102 7.2.1.3 Plume Heights in Transient Eruptions 105 7.3 Transient Eruptions Involving External Water 106 7.3.1 Types of Hydromagmatic Eruptions 106 7.3.2 Mechanisms of Violent Magma–Water Interactions 108 7.3.3 Tephra from Hydromagmatic Eruptions 108 7.4 Summary 108 7.5 Further Reading 109 7.6 Questions to Think About 109 8 Pyroclastic Falls and Pyroclastic Density Currents 111 8.1 Introduction 111 8.2 Fallout of Clasts from Eruption Columns 111 8.2.1 Fallout from the Rising Eruption Column 111 8.2.2 Fallout from the Umbrella Region 113 8.2.3 Fall Speeds of Pyroclasts 113 8.2.4 Other Factors Affecting Fallout from Eruption Columns 115 8.2.5 Common Features of Fall Deposits 116 8.3 The Application of Eruption Column Models 117 8.3.1 Analyzing a Fall Deposit 117 8.3.2 Estimating the Eruption Rate and the Eruption Speed 118 8.3.3 Finding the Wind Speed 120 8.3.4 Finding the Fall Deposit Volume and the Eruption Duration 121 8.3.5 Fall Deposits: Summary 121 8.4 Pyroclastic Density Currents and Their Deposits 122 8.4.1 Origins of Pyroclastic Density Currents 122 8.4.1.1 Column Collapse and Pyroclastic Fountaining 122 8.4.1.2 Directed Blasts and Collapses from Lava Domes and Flows 123 8.4.2 Pyroclastic Density Current Emplacement Processes 124 8.4.3 Nature of the Deposits 128 8.5 Summary 129 8.6 Further Reading 130 8.7 Questions to Think About 131 9 Lava Flows 133 9.1 Introduction 133 9.2 Origin of Lava Flows 133 9.3 Types of Lava Flows 133 9.4 Lava Flow Rheology 138 9.5 Rheological Control of Lava Flow Geometry 140 9.6 Lava Flow Motion 143 9.7 Lengths of Lava Flows 144 9.8 Surface Textures of Lava Flows 145 9.9 Effects of Ground Slope and Lava Viscosity 149 9.10 Summary 149 9.11 Further Reading 151 9.12 Questions to Think About 151 10 Eruption Styles, Scales, and Frequencies 153 10.1 Introduction 153 10.2 Chemical Composition and Styles of Volcanic Activity 153 10.3 Chemical Composition and Effusive Eruptions 155 10.3.1 Conditions of Effusive Eruption 155 10.3.2 Chemical Composition and Lava Flows 157 10.4 Chemical Composition and Explosive Eruptions 157 10.4.1 Transient and Sustained Explosive Activity 157 10.4.2 Chemical Composition and Transient Explosive Activity 158 10.4.3 Chemical Composition and Sustained Explosive Eruptions 160 10.4.3.1 Role of Viscosity 160 10.4.3.2 Role of Gas Content 161 10.5 Summary of Compositional Controls on Eruption Character 161 10.6 Magnitudes and Frequencies of Volcanic Eruptions 163 10.6.1 The Magnitude of Historic Volcanic Eruptions 163 10.6.2 The Magnitude of Volcanic Eruptions in the Geological Record 166 10.6.3 The Frequency of Volcanic Eruptions 167 10.6.4 Magma Reservoirs and Eruption Magnitude and Frequency 167 10.7 Elastic and Inelastic Eruptions and the Contribution of “Mush” 168 10.8 Eruptions of Exceptional Magnitude 171 10.8.1 Introduction 171 10.8.2 Large Ignimbrite-Forming Eruptions 171 10.8.3 Flood Basalt Eruptions 171 10.9 Summary 172 10.10 Further Reading 173 10.11 Questions to Think About 174 11 Volcanic Hazards and Volcano Monitoring 175 11.1 Introduction 175 11.2 Types of Volcanic Hazards 175 11.2.1 Lava Flows 175 11.2.2 Pyroclastic Falls 176 11.2.3 Ash in the Atmosphere 178 11.2.4 Pyroclastic Density Currents and Surges 179 11.2.5 Lahars 180 11.2.6 Jökulhlaups 181 11.2.7 Volcanic Gases 182 11.3 Hazard Assessment 183 11.4 Monitoring Volcanoes and Short-term Eruption Prediction 185 11.5 Hazard Mitigation 188 11.6 Summary 189 11.7 Further Reading 189 11.8 Questions to Think About 190 12 Volcanoes and Climate 191 12.1 Introduction 191 12.2 Evidence for the Impact of Volcanic Eruptions on Climate 191 12.3 Satellite Monitoring of Climate Change After Volcanic Eruptions 194 12.4 The Effects of Volcanic Eruptions on Climate 195 12.4.1 The Influence of Plume Height on Climate Change 196 12.4.2 The Effect of Geographical Location on Climate Impact 196 12.4.3 The Effects of Eruption Volume on Climate Impact 196 12.4.4 The Effects of Magma Composition on Climate Impact 198 12.4.5 The Effects of Eruption Duration on Climate Impact 198 12.5 Volcanoes and Mass Extinctions 199 12.6 Summary 200 12.7 Further Reading 201 12.8 Questions to Think About 201 13 Volcanism on Other Planets 203 13.1 Introduction 203 13.2 Volcanically Active Bodies in the Solar System 203 13.3 The Effects of Environmental Conditions on Volcanic Processes 206 13.4 The Moon 208 13.5 Mars 212 13.6 Venus 216 13.7 Mercury 218 13.8 Io 220 13.9 Europa 222 13.10 Differentiated Asteroids 223 13.11 Summary 224 13.12 Further Reading 224 13.13 Questions to Think About 224 Answers to Questions 225 Index 231

About the Author :
Elisabeth Parfitt was previously a lecturer in Physical Volcanology at the University of Leeds and an Honorary Research Fellow at Lancaster University in the UK. She also spent time in the USA as a Research Scientist at Brown University and at the State University of New York at Buffalo. She currently works as an Archivist in North Wales. Lionel Wilson is Emeritus Professor of Earth and Planetary Sciences at Lancaster University, UK. He is also a Visiting Professor at the University of Hawai‘i and Brown University in the USA. Laura Kerber is a Research Scientist at NASA’s Jet Propulsion Laboratory and a Visiting Associate in Planetary Sciences at the California Institute of Technology.