Volcanic eruptions are common, with more than 50 volcanic eruptions in the United States alone in the past 31 years. These eruptions can have devastating economic and social consequences, even at great distances from the volcano. Fortunately many eruptions are preceded by unrest that can be detected using ground, airborne, and spaceborne instruments. Data from these instruments, combined with basic understanding of how volcanoes work, form the basis for forecasting eruptionsâ€"where, when, how big, how long, and the consequences. Accurate forecasts of the likelihood and magnitude of an eruption in a specified timeframe are rooted in a scientific understanding of the processes that govern the storage, ascent, and eruption of magma. Yet our understanding of volcanic systems is incomplete and biased by the limited number of volcanoes and eruption styles observed with advanced instrumentation. Volcanic Eruptions and Their Repose, Unrest, Precursors, and Timing identifies key science questions, research and observation priorities, and approaches for building a volcano science community capable of tackling them. This report presents goals for making major advances in volcano science.

By the year 2000, the number of people at risk from volcanic hazards is likely to increase to around half a billion. Since 1980, significant advances have been made in volcano monitoring, the data from which provides the sole scientific basis for eruption prediction. Here, internationally renowned and highly experienced specialists provide 25 comprehensive articles covering a wide range of related topics: monitoring techniques and data analysis; modelling of monitoring data and eruptive phenomena; volcanic hazards and risk assessment; and volcanic emergency management. Selected case histories of recent volcanic disasters, such as Mount Pinatubo in the Philippines, demonstrate that effective communication - between scientists, civil authorities, the media and the population at risk - is essential to reducing the danger.

Volcanoes release gases to the atmosphere both during and between eruptive phases. Primary and secondary processes occurring within the mantle and crust control the gases’ chemical and isotopic compositions as well as their emission rates. Therefore by measuring these gases a wealth of scientific information concerning the source and fate of these fluids is provided. Fluid geochemistry has been highly useful in advancing both our fundamental scientific understanding and procedures for operational volcano monitoring and eruption forecasting. Gases from low-to-high temperature fumaroles and those diffusively released through the soils of volcanic flanks are investigated using various sampling and measurement techniques. Furthermore, a variety of remote sensing methods are applied at relatively great distances from the source to gather major gas composition and flux data for volcanic plumes using ground based, airborne (including UAV) and space borne platforms. The acquired data have advanced science in a number of key ways: • firstly, with parallel thermodynamical modelling to advance our capacity to interpret acquired degassing data; • secondly, through improved constraints on budgets for volcanically mediated geochemical cycling, particularly via regional subduction processes; • thirdly, through improved constraints on the effects of volcanic gases on atmospheric composition, chemistry and radiative transfer, particularly in terms of halogen chemistry, volcanogenic climate change and impacts on human health; • fourthly, there has been a growing body of work focused on combining degassing data with contemporaneous geophysical data and studies on conduit fluid dynamics to advance our understanding of how subterranean gas flow mediates activity at the surface; • and fifthly, there have been considerable advances in the methods themselves, used to make the gas measurements, in particular in terms of extractive sampling (e.g., using MultiGAS units, mass spectrometry, spectroscopic isotope measurement approaches and diffusive denuder sampling) and remote sensing approaches (e.g., DOAS, UV cameras and other imaging techniques, LIDAR and FT)

Statistics in Volcanology is a comprehensive guide to modern statistical methods applied in volcanology written by today's leading authorities. The volume aims to show how the statistical analysis of complex volcanological data sets, including time series, and numerical models of volcanic processes can improve our ability to forecast volcanic eruptions. Specific topics include the use of expert elicitation and Bayesian methods in eruption forecasting, statistical models of temporal and spatial patterns of volcanic activity, analysis of time series in volcano seismology, probabilistic hazard assessment, and assessment of numerical models using robust statistical methods. Also provided are comprehensive overviews of volcanic phenomena, and a full glossary of both volcanological and statistical terms. Statistics in Volcanology is essential reading for advanced undergraduates, graduate students, and research scientists interested in this multidisciplinary field.

For many centuries people living on volcanoes have known that the outset of seismic activity is often a forerunner of a volcanic eruption. This understand ing allowed people living close to the sites of the Mt. Nuovo 1538 eruption at Campi Flegrei, Italy, and of the Mt. Usu 1663 eruption, in Hokkaido, Japan (to quote only two examples) to flee before the eruptions started. During the second half of the 19th century seismographs were installed on some volcanoes, and the link between seismic and eruptive activity started to be assessed on a firmer scientific basis. The first systematic observations of the correlations existing between seismic activity and volcanic eruptions were probably those carried out at Mt. Vesuvius by Luigi Palmieri in 1856. Palmieri was the Director of Osservatorio Vesuviano and built an electromagnetic seismograph with the aim of "making visible the smallest ground motions by recording them on paper and indicating direction, intensity and duration". He was able to show the relationship between earthquakes and the different phases of volcanic activity. He identified the harmonic tremor which he indicated was a precursor of volcanic activity: "the characteristic feature of the ground mo tions preceding eruption is its continuity . . . (before the eruption of 1861) the electromagnetic seismograph began to show a continuous tremor". The Palmieri seismograph was also utilized in Japan until 1883, when it was replaced by the new Gray-Milne seismographs, and, later, by the Omori in struments.

This open access book summarizes the findings of the VUELCO project, a multi-disciplinary and cross-boundary research funded by the European Commission's 7th framework program. It comprises four broad topics: 1. The global significance of volcanic unrest 2. Geophysical and geochemical fingerprints of unrest and precursory activity 3. Magma dynamics leading to unrest phenomena 4. Bridging the gap between science and decision-making Volcanic unrest is a complex multi-hazard phenomenon. The fact that unrest may, or may not lead to an imminent eruption contributes significant uncertainty to short-term volcanic hazard and risk assessment. Although it is reasonable to assume that all eruptions are associated with precursory activity of some sort, the understanding of the causative links between subsurface processes, resulting unrest signals and imminent eruption is incomplete. When a volcano evolves from dormancy into a phase of unrest, important scientific, political and social questions need to be addressed. This book is aimed at graduate students, researchers of volcanic phenomena, professionals in volcanic hazard and risk assessment, observatory personnel, as well as emergency managers who wish to learn about the complex nature of volcanic unrest and how to utilize new findings to deal with unrest phenomena at scientific and emergency managing levels. This book is open access under a CC BY license.

This book comprises the selected proceedings of the 3rd International Workshop on Natural Hazards (NATHAZ’22), Angra do Heroísmo, Terceira Island, Azores, 2022. The book interests all researchers and practitioners in Earth Sciences, Volcanic Risks, Natural Hazards, Geoethics, Environmental Sciences and Engineering. Terceira is a volcanic island with volcanic systems with caldera (Cinco Picos, Guilherme Moniz, Santa Bárbara and Pico Alto central volcanoes) and an active fissural zone defined by various alignments of small volcanic cones, lava domes and fault zones. The agricultural landscape, the natural and forest reserve, as well as the natural pools make the island a unique place to visit. The historic downtown of Angra do Heroísmo is a UNESCO world heritage, and several iconic buildings witness the island’s geodynamic history. Natural hazards result from a threat of a naturally occurring event that will have a negative effect on humans. That damaging effect is often called natural disasters. Among the natural hazards and potential disasters to be considered are: earthquakes, volcanic eruptions, landslides, subsidence, floods, droughts and coastal erosion. In addition, anthropogenic hazards occur as a result of human interaction with the environment. They comprise technological risks due to exposure to hazardous substances in the environment. Natural systems in different frameworks require a comprehensive understanding of climatology, geology, hydrology and volcanic data, processes and dynamics. Thus, it is important to perform hazard and risk assessment studies to accomplish hazard mitigation. In addition, it highlighted the role of variability and climate change in Earth systems. Furthermore, an accurate understanding of the natural systems and interactions with engineering, geodiversity and natural resources is vital to the entire socioeconomic sector. This book is expected to offer an overview of natural hazards in model regions in Europe, America, Asia and the Atlantic islands. It gives new insights into the characterization, assessment, protection, and modelling of geological hazards, volcanic systems, urban areas, coastal zones and engineering approaches by international researchers and professionals. The scientific committee comprises lead geoscientists, natural hazards related practitioners, and academics worldwide. The main topics include: 1. Multi-hazards and risks: sustainable society, disasters and geoethics 2. Natural hazards and assessment: rock falls, landslides, urban planning and management 3. Sustainable Earth systems: hazards and climate change 4. Terceira Island geology and geodiversity: meeting volcanological hazards in the Azores