1 The modern volcanologist's tool kit.- 1.1 Volcanoes in motion - when deformation gets extreme.- 1.2 Volcanology in the information age.- 1.3 A brief survey of volcano-monitoring techniques.- 1.4 An introduction to geodetic sensors and techniques.- 2 Classical surveying techniques.- 2.1 Early geodetic surveys.- 2.2 Reference systems and datums.- 2.3 Geodetic networks.- 2.4 Trilateration and triangulation.- 2.5 Leveling and tilt-leveling surveys.- 2.6 Photogrammetry.- 2.7 Microgravity surveys.- 2.8 Magnetic field measurements.- 3 Continuous monitoring with in situ sensors.- 3.1 Seismometers.- 3.2 Tiltmeters.- 3.3 Strainmeters.- 3.4 Continuous GPS.- 3.5 Some cautions about near-surface deformation sensors.- 3.6 Continuous gravimeters.- 3.7 Differential lake gauging.- 3.8 Concluding remarks.- 4 The Global Positioning System: A multipurpose tool.- 4.1 Global positioning principles.- 4.2 An overview of GPS, GLONASS, and Galileo.- 4.3 GPS signal structure: what do the satellites broadcast?.- 4.4 Observables: what do GPS receivers measure?.- 4.5 Data combinations and differences.- 4.6 Doing the math: turning data into positions.- 4.7 Relative positioning techniques.- 4.8 CGPS networks.- 4.9 Data processing.- 4.10 Looking to the future.- 5 Interferometric synthetic-aperture radar (InSAR).- 5.1 Radar principles and techniques.- 5.2 Principles of SAR interferometry.- 5.3 Examples of interferometric SAR applied to volcanoes.- 6 Photogrammetry.- 6.1 Introduction.- 6.2 Historical perspective.- 6.3 Photogrammetry fundamentals.- 6.4 Instrumentation and data types.- 6.5 Aerotriangulation.- 6.6 Terrestrial photogrammetry.- 6.7 Application to Mount St. Helens.- 7 Lessons from deforming volcanoes.- 7.1 Mount St. Helens - edifice instability and dome growth.- 7.2 K?lauea volcano, Hawai'i - flank instability and gigantic landslides.- 7.3 Yellowstone - the ups and downs of a restless caldera.- 7.4 Long Valley Caldera and the Mono-Inyo volcanic chain: two decades of unrest (and still counting?).- 8 Analytical volcano deformation source models.- 8.1 Introduction.- 8.2 The elastic half-space: a first approximation of the Earth.- 8.3 Notation.- 8.4 Surface loads.- 8.5 Point forces, pipes, and spheroidal pressure sources.- 8.6 Dipping point and finite rectangular tension cracks.- 8.7 Gravity change.- 8.8 Relationship between subsurface and surface volume changes.- 8.9 Topographic corrections to modeled deformation.- 8.10 Inversion of source parameters from deformation data.- 9 Borehole observations of continuous strain and fluid pressure.- 9.1 Borehole strainmeter design and capabilities.- 9.2 Groundwater level as a volumetric strain indicator.- 9.3 Processing and analyzing continuous strain and water level data.- 9.4 Volumetric strain fields of idealized volcanic sources.- 9.5 Examples.- 9.6 Summary.- 10 Hydrothermal systems and volcano geochemistry.- 10.1 The hydrologic importance of brittle-plastic phenomena.- 10.2 The brittle-plastic transition.- 10.3 Development of plastic rock around shallow intrusive bodies.- 10.4 Storage of hydrothermal fluid in and movement through plastic rock.- 10.5 Self-sealing at the brittle-plastic interface.- 10.6 Mechanisms for breaching the self-sealed zone and discharge of >400°C fluid into cooler rock.- 10.7 Chemical characteristics of fluids in a sub-volcanic environment.- 10.8 A general model of hydrothermal activity in a sub-volcanic environment.- 10.9 Uplift and subsidence of large silicic calderas.- 10.10 Conclusions.- 11 Challenges and opportunities for the 21st century.- 11.1 The intrusion process: a complicated business.- 11.2 Strengths and weaknesses of geodetic monitoring.- 11.3 Why is volcano deformation such an elusive target?.- 11.4 Capturing volcano deformation in space and time.- 11.5 Pie-in-the-sky volcanology.- 11.6 A bright and challenging future.- References.- DVD with figures and supplementary material.
