Volcano-Tectonic Processes

Volcanoes have terrified and, at the same time, fascinated civilizations for thousands of years. Many aspects of volcanoes, most notably the eruptive processes and the compositional variations of magma, have been widely investigated for several decades and today constitute the core of any volcanology textbook. Nevertheless, in the last two decades, boosted by the availability of volcano monitoring data, there has been an increasing interest in the pre-eruptive processes related to the shallow accumulation and to the transfer of magma approaching the surface, as well as in the resulting structure of volcanoes. These are innovative and essential aspects of modern volcanology and, as driving volcanic unrest, their understanding also improves hazard assessment and eruption forecasting. So far, the significant progress made in unravelling these volcano-tectonic processes has not been supported by a comprehensive overview.

This monograph aims at filling this gap, describing the pre-eruptive processes related to the structure, deformation and tectonics of volcanoes, at the local and regional scale, in any tectonic setting. The monograph is organized into three sections ("Fundamentals", "Magma migration towards the surface" and "The regional perspective"), consisting of thirteen chapters that are lavishly illustrated. The reader is accompanied in a journey within the volcano factory, discovering the processes associated with the shallow accumulation of magma and its transfer towards the surface, how these control the structure of volcanoes and their activity and, ultimately, improve our ability to estimate hazard and forecast eruption.

The potential readership includes any academic, researcher and upper undergraduate student interested in volcanology, magma intrusions, structural geology, tectonics, geodesy, as well as geology and geophysics in general.

Auteur
Valerio Acocella, professor of Volcano-Tectonics and Volcanic Risk at the University of Roma Tre, Rome, Italy, has been studying volcanoes worldwide for more than two decades, publishing approximately 150 scientific papers. He has coordinated large research projects on Etna and Campi Flegrei, as well as the IAVCEI Commission on Calderas. He has been serving as editor for several scientific journals and organizing sessions at many scientific meetings.

Contenu

Part I: Fundamentals

Chapter 1 - Volcanoes and volcanic activity

1.1 - Introduction

1.2 - Volcano distribution

1.3 - Volcano composition

1.4 - Monogenic and polygenic volcanoes

1.5 - Volcano alignment and elongation

1.6 Types of volcanic edifices

1.7 - Volcanic activity

1.8 - Effusive eruptions

1.9 - Explosive eruptions

1.10 - Volcanic hazard and risk 1.11 - Summary

Chapter 2 Crustal deformation

2.1 - Introduction

2.2 Stress

2.3 - Strain

2.4 - Elastic deformation 2.5 - Brittle deformation

2.6 - The seismic cycle

2.7 - Ductile deformation

2.8 - Rheology of the crust and the magma

2.9 - Summary

Part II: Magma migration to the surface

Chapter 3 - Rise of magma through the crust: diapirs, dikes

3.1 - Introduction 3.2 Magmatic diapirs

3.3 - Dikes

3.4 - Mechanics of dike formation

3.5 - Mechanics of dike propagation

3.6 - Summary

Chapter 4 - Magma emplacement: magma reservoirs

4.1 - Introduction

4.2 General features

4.3 - Sills

4.4 - Laccoliths

4.5 - Lopoliths

4.6 - Magma chambers

4.7 - Mechanism of pluton emplacement

4.8 - The plutonic-volcanic link

4.9 - Summary

Chapter 5 - Vertical collapses: calderas

5.1 - Introduction

5.2 General features of calderas

5.3 Geological and geophysical evidence of caldera structure and development 5.4 Modelling caldera structure and development

5.5 Relationships to regional tectonics 5.6 - Classification of calderas

5.7 Caldera structure and eruptions

5.8 - Caldera resurgence: resurgent domes and blocks 5.9 - Caldera unrest

5.10 - Summary

Chapter 6 - Lateral collapses: flank instability

6.1 - Introduction

6.2 - General features

6.3 - Anatomy of an unstable flank

6.4 - Causes of flank instability

6.5 - Analysis of flank instability

6.6 - Flank instability in mafic volcanoes

6.7 - Flank instability in felsic volcanoes

6.8 - Multi-hazard related to flank instability

6.9 - Summary

Chapter 7 Magma transfer within volcanic edifices

7.1 - Introduction

7.2 Regional, radial and circumferential dikes

7.3 - Dike propagation within volcanic edifices

7.4 - Dike propagation in calderas

7.5 - Cryptodomes

7.6 Necks and plugs 7.6 - Summary

Chapter 8 - Volcano unrest 8.1 - Introduction

8.2 General features

8.3 Monitoring volcanoes 8.4 - Magmatic trigger: deformation source models

8.5 - Sei...