Hazards and Monitoring of Volcanic Activity, Volume 3: Gravimetric, Electric and Magnetic Fluids, Products and Methods

Description

The impact of natural disasters has become an important and ever-growing preoccupation for modern societies. Volcanic eruptions are particularly feared due to their devastating local, regional or global effects. Relevant scientific expertise that aims to evaluate the hazards of volcanic activity and monitor and predict eruptions has progressively developed since the start of the 20th century. The further development of fundamental knowledge and technological advances over this period have allowed scientific capabilities in this field to evolve. Hazards and Monitoring of Volcanic Activity groups a number of available techniques and approaches to render them easily accessible to teachers, researchers and students. This volume reviews the different monitoring methods. It first considers fluids and solid products, approaches that provide valuable information on pre-eruptive processes and eruption dynamics. It also focuses on the description of geophysical monitoring methods under development. Cover Half-Title Page Title Page Copyright Page Contents Foreword Preface List of Abbreviations Chapter 1. Monitoring of Volcanic Fluids 1.1. Introduction 1.2. Composition, solubility and exsolution of magmatic gases 1.2.1. Composition 1.2.2. Solubility and exsolution 1.3. In situ sampling and analysis techniques for volcanic fluids 1.3.1. Monitoring of fumarole compositions by Giggenbach ampoules 1.3.2. Monitoring of the compositions and gas fluxes of the diluted plume 1.3.3. Representativeness of samples/measurements in fumaroles (undiluted) and plumes: comparison of techniques 1.3.4. Monitoring of diffuse degassing 1.3.5. Dissolved gases in hot springs 1.4. Contribution of melt inclusions to geochemical monitoring 1.5. Example of monitoring 1.5.1. Gas monitoring of Poas volcano (Costa Rica): identification of phreatic and phreatomagmatic eruption precursors (based on 1.6. Recommendations for fluid monitoring 1.7. References Chapter 2. Monitoring of Eruptive Products: Deposits Associated with Pyroclastic Fallout 2.1. Introduction 2.2. General characteristics of pyroclastic fallout deposits 2.3. Importance of the scale of analysis (from whole deposit to particles) 2.4. Sampling and synand post-eruptive parameters 2.5. Pyroclastic scale measurements 2.5.1. Particle size and distribution 2.5.2. Syn-eruptive methods for determining pyroclast size and pyroclast size distribution 2.5.3. Post-eruptive methods for determining pyroclast size and pyroclast size distribution 2.5.4. Particle size parameters 2.5.5. Identification of pyroclastic components 2.5.6. Post-eruptive techniques to determine particle morphology 2.5.7. Terminal fall velocity of the particles 2.5.8. Pyroclast density and porosity 2.5.9. Pyroclast permeability 2.6. Petrographic and geochemical analysis of pyroclastic products 2.6.1. Petrological observation of pyroclasts 2.6.2. Pyroclast composition 2.6.3. Magma temperature 2.6.4. Crystals in equilibrium: pre-eruptive conditions in magma reservoirs 2.6.5. Crystals in disequilibrium: diffusion and kinetics of magmatic processes 2.6.6. Radiogenic isotopes 2.7. Measurements at the scale of pyroclastic deposits 2.7.1. Dispersion axis and dispersal area 2.7.2. Mass load 2.7.3. Volume 2.8. Total grain size distribution 2.8.1. Syn-eruptive methods for determining TGSD 2.8.2. Post-eruptive methods for determining TGSD 2.9. Plume heights 2.9.1. Syn-eruptive methods for determining plume heights 2.9.2. Post-eruptive methods for determining plume heights 2.10. Mass discharge rate 2.10.1. Syn-eruptive methods to determine the MDR 2.10.2. Post-eruptive methods to determine the MDR 2.11. Temperature 2.11.1. Syn-eruptive methods to determine the temperature 2.11.2. Post-eruptive methods for determining temperature 2.12. Ballistic parameters 2.12.1. Syn-eruptive methods for determining ballistic trajectories 2.12.2. Post-eruptive methods for determining the ballistic landing position map and ballistic flight parameters 2.13. References Chapter 3. Monitoring of Eruptive Products: Pyroclastic Density Currents and Their Deposits 3.1. Introduction 3.2. General characteristics of pyroclastic density currents and their deposits 3.3. The importance of scale in the joint study of deposition and individual particles 3.4. Syn-eruptive and post-eruptive measurements 3.4.1. Particle scale measurements 3.4.2. Deposit scale measurements 3.5. Perspectives 3.6. References Chapter 4. Gravity Monitoring of Volcanoes 4.1. Introduction 4.2. Instruments 4.3. Measurement procedures 4.3.1. Ground-level gravimetry 4.3.2. On-board mobile gravimetry 4.3.3. Space gravimetry 4.4. External phenomena generating temporal variations of gravity 4.4.1. Seismic noise and wind 4.4.2. Atmospheric pressure 4.4.3. Land and ocean tides 4.4.4. Hydrological reservoirs 4.4.5. Altitude variations and deformation 4.5. Causes of gravimetric variations on volcanoes 4.5. Causes of gravimetric variations on volcanoes 4.5.1. Evolution of hydrothermal systems 4.5.2. Evolution of magma systems 4.5.3. Volcano-tectonic phenomena 4.6. Case studies 4.6.1. Monitoring and evolution of a magma reservoir at Kilauea 4.6.2. Follow-up of an intrusion and a collapse at Piton de la Fournaise 4.7. Study and monitoring by muography 4.7.1. Overview 4.7.2. Instruments 4.7.3. Measurements and data 4.7.4. Case studies 4.8. Perspectives 4.9. Acknowledgment 4.10. References Chapter 5. Electrical and Electromagnetic Monitoring of Volcanoes 5.1. Introduction 5.2. Phenomena at the origin of resistivity and electric or EM field variations 5.2.1. Reminder on the resistivity of rocks 5.2.2. Causes of rock resistivity variation in the volcanic domain 5.3. Natural and induced electric and EM fields 5.4. Monitoring: instruments and procedures 5.4.1. Direct current monitoring 5.4.2. EM monitoring 5.5. Perspectives 5.6. Acknowledgment 5.7. References Chapter 6. Magnetic Monitoring of Volcanoes 6.1. Introduction 6.2. Phenomena generating magnetization and magnetic field variations 6.2.1. Piezomagnetism 6.2.2. Thermomagnetism 6.2.3. Electrokinetic effects 6.2.4. Other mechanisms 6.3. Monitoring: instruments and procedures 6.4. Case studies 6.4.1. Periodic monitoring 6.4.2. Continuous monitoring 6.5. Perspectives 6.6. Acknowledgment 6.7. References List of Authors Index EULA