Characterizing Volcanic Behaviour Using Thermal Remote Sensing And Other Time Series Data 2000 2009 Volcan De Colima Mexico

This thesis examines if a protocol can be created using satellite and existing ground-based time series data recorded at Mexico's most active volcano, Volcán de Colima, over an extended time period (five years), to identify past patterns in the behaviour of the volcano. Thermally anomalous pixels due to volcanic activity are identified on MODIS and GOES satellite images by customizing thresholds in the hybrid approach algorithm to locate pixels with radiance values that exceed the normal background radiance and natural variance at Volcán de Colima. Visual comparison of the resulting thermal anomaly time series with RSEM, mean temperature, and precipitation time series data, and volcanic activity reports yield four common observation types. Furthermore, inspection and comparison of the data sets reveal that additional data requirements and advanced statistical analysis are required to fully characterize past volcanic behaviour for use as a tool to forecast future activity.

This book represents a comprehensive coverage of the current state of knowledge of Volcán de Colima: its history, its eruptive mechanism, the generation and interpretation of monitoring data, and the risk presented to the local population. The volume pulls together the results of the most important studies of recent years from many areas of volcanology: the geology of its eruptive products; geophysical and geochemical studies of the signals measured that relate to the generation and movement of magma; experimental analysis of its internal processes and the social complexities relating to the risk imposed by future eruptions. Volcán de Colima is an important volcano: it has frequent large Plinian or sub-Plinian eruptions; its activity frequently switches between various regimes, which provides the opportunity to study these transitions from their cause to their impact; and it is a volcano which poses a significant threat to a large population.

Encapsulating over one hundred years of research developments, this book is a comprehensive manual for measurements of Earth surface temperatures and heat fluxes, enabling better detection and measurement of volcanic activity. With a particular focus on volcanic hot spots, the book explores methodologies and principles used with satellite-, radiometer- and thermal-camera data. It presents traditional applications using satellite and ground based sensors as well as modern applications that have evolved for use with hand-held thermal cameras and is fully illustrated with case studies, databases and worked examples. Chapter topics include techniques for thermal mixture modelling and heat flux derivation, and methods for data collection, mapping and time-series generation. Appendices and online supplements present additional specific notes on areas of sensor application and data processing, supported by an extensive reference list. This book is an invaluable resource for academic researchers and graduate students in thermal remote sensing, volcanology, geophysics and planetary studies.

Volcano instability refers to the condition where a volcanic edifice has reached a state of destabilization that increases the likelihood that all or part of the edifice will undergo structural failure. Flank instability can arise from complex interactions between gravity forces, magmatic activity, and local or regional tectonics, and develop over a variety of timescales and lengthscales. Despite debris avalanches resulting from the catastrophic failure of volcanic flanks taking place at a frequency of 5 every 100 years, and causing over 20,000 fatalities in the past 400 years, flank motion only attained recognition as an important process in the mid-20th century, so its expression and drivers are poorly understood relative to those of other volcanic processes. The purpose of this dissertation is to investigate the occurrence of long-term flank instability at volcanoes, including the processes, precursory signals and conditions required to develop and sustain volcanic flank creep. This is motivated by the need to better understand the conditions under which catastrophic flank collapse will take place and to identify precursory activity that could enable suitable hazard assessment and early warning for risk mitigation purposes. Specifically, I present research on volcanic flank instability and its interaction with magmatic activity. The emphasis is on improving observations of flank instability through satellite remote sensing and leveraging models to better understand the relative contributions of different processes to flank instability. This dissertation is composed of four main chapters: the first three focus on an active volcano in Guatemala, Pacaya, where previous studies have shown evidence for flank instability, whereas the fourth is a parametric study applicable to the range of volcano geometries in nature. The first chapter focuses on the detection and modeling of low magnitude flank creep at Pacaya. The second presents a conceptual model for the links between flank creep behaviour and volcanic unrest at Pacaya. The third focuses on validating the conceptual model and testing the performance of different radar satellite platforms to detect ground motion as well as the applicability of single-station seismic analyses to monitor eruption evolution. The final chapter addresses the impact of volcano and fault geometry on the likelihood of developing magma driven flank instability. Despite the prevalence of debris avalanches across volcanic settings, flank instability has mostly been considered at ocean island volcanoes. In Guatemala, all but one volcano with elevation >2000 m have undergone edifice failure. Pacaya is one of these Guatemalan volcanoes, which experienced at least one past episode of flank collapse and where recent transient flank motion was identified during two large eruptions in 2010 and 2014. I investigate the existence of long-term slip at Pacaya through a time-series analysis method that enables retrieval of long-term signals by combining information from multiple shorter interval radar satellite image pairs and reveal, for the first time, long-term displacement of the southwest flank of Pacaya between 2010 and 2014. Through inverse geodetic modeling and analysis of stress changes, I find that that the observed flank motion could be accommodated by slip on a southwest-dipping detachment fault, with an observed increase in slip rate attributed to magma intrusion during a major eruption in 2014. The identification of long-term flank creep and its modulation by magmatic activity at Pacaya between 2012 and 2014 raised the question of whether creep was ongoing and how other instances of lava flow effusion and explosive activity relate to flank motion. Thus, I investigated the links between flank creep rates and eruptive behavior at Pacaya, to better constrain the conditions under which flank creep can be initiated, sustained, or halted at active volcanoes. I computed time-series of surface displacements from 2007 to 2020 using seven radar satellite datasets to quantify flank creep rates and compiled volcanic activity reports, ash advisories, thermal anomalies, and lava flow maps to describe the concurrent eruptive activity. The observations were combined into a conceptual model showing how during periods of elevated volcanic unrest attributed to open-vent volcanic activity, magma migrates in an open conduit with little associated deformation or flank motion, whereas during activity involving the opening of new vents outside the summit area, transient flank creep can be initiated. Pacaya underwent another heightened period of volcanic activity in early 2021, as the culmination of effusive and explosive activity starting in mid-2015. Given the association of past vigorous eruptive activity from vents beyond the summit area with initiation or acceleration of flank creep, I assessed whether this process repeated itself in 2021. I also leveraged the availability of radar data availability from 5 different satellite platforms with different spatial and temporal resolutions to assess the relative performance of different platforms for monitoring volcanic eruptions. Ground displacement time-series results revealed subsidence and westward displacements on the southwest flank that are compatible with down-dip motion, but might include contributions from lava flow compaction and seasonal tropospheric water vapor variations. Overall, results highlight the advantage of high resolution SAR amplitude imagery for mapping surface changes, the vulnerability to geometric distortions of low incidence angle platforms, and the obstacle of reliance on tasking to obtain imagery over volcanoes, as well as the need for advanced techniques to unravel sources of ground motion signals. An additional seismic dataset revealed that real-time seismic amplitude measurement peaks reflect the vigor of magma effusion and single-station correlations capture the effects of rainfall, but gaps and noise in the datasets impeded identifying any characteristic signals coincident with changes in eruptive activity or flank displacement trends. To further the understanding of the complex interplay between magmatic intrusion and volcanic flank creep observed at Pacaya, but also at other volcanoes, I carried out a parametric study using numerical models. Specifically, I assessed how edifice slope, the geometry of faults, and intrusion depth affect the potential for the development of magma-driven flank instability at volcanoes. I quantified whether each modeled condition would be conducive or detrimental to slip through calculation of stress changes on example receiver faults for endmember scenarios in nature. Additionally, the surface displacements for each case were extracted, to highlight deviations from the displacements that would be obtained through more commonly used analytical models that neglect relief. Development of instability is most likely when receiver faults have shallow dips and the dike intrusion spans the edifice, regardless of edifice steepness, or in steep edifices when receiver faults have steep dips and the dike is beneath the edifice. Neglecting topography yields different magnitudes and extents of surface deformation and stress changes.

Remote sensing data and methods are increasingly being implemented in assessments of volcanic processes and risk. This happens thanks to their capability to provide a spectrum of observation and measurement opportunities to accurately sense the dynamics, magnitude, frequency, and impacts of volcanic activity. This book includes research papers on the use of satellite, aerial, and ground-based remote sensing to detect thermal features and anomalies, investigate lava and pyroclastic flows, predict the flow path of lahars, measure gas emissions and plumes, and estimate ground deformation. The multi-disciplinary character of the approaches employed for volcano monitoring and the combination of a variety of sensor types, platforms, and methods that come out from the papers testify to the current scientific and technology trends toward multi-data and multi-sensor monitoring solutions. The added value of the papers lies in the demonstration of how remote sensing can improve our knowledge of volcanoes that pose a threat to local communities; back-analysis and critical revision of recent volcanic eruptions and unrest periods; and improvement of modeling and prediction methods. Therefore, the selected case studies also demonstrate the societal impact that this scientific discipline can potentially have on volcanic hazard and risk management.

This volume focuses on how advances in both remote sensing and modelling can be brought together to improve our understanding of the behaviour of active volcanoes. It includes review papers, papers reporting technical advances and case studies showing how the integration of remote-sensing observations with models can be put to good use.

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.

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.

This doctoral thesis applies measurements of ground deformation from satellite radar using their potential to play a key role in understanding volcanic and magmatic processes throughout the eruption cycle. However, making these measurements is often problematic, and the processes driving ground deformation are commonly poorly understood. These problems are approached in this thesis in the context of the Cascades Volcanic Arc. From a technical perspective, the thesis develops a new way of using regional-scale weather models to assess a priori the influence of atmospheric uncertainties on satellite measurements of volcano deformation, providing key parameters for volcano monitoring. Next, it presents detailed geodetic studies of two volcanoes in northern California: Medicine Lake Volcano and Lassen Volcanic Centre. Finally, the thesis combines geodetic constraints with petrological inputs to develop a thermal model of cooling magma intrusions. The novelty and range of topics covered in this thesis mean that it is a seminal work in volcanic and magmatic studies.

An advanced textbook and reference resource examining the physics of volcanic behavior and the state of the art in modeling volcanic processes.