Statistical Methods And Modeling Of Seismogenesis

The study of earthquakes is a multidisciplinary field, an amalgam of geodynamics, mathematics, engineering and more. The overriding commonality between them all is the presence of natural randomness. Stochastic studies (probability, stochastic processes and statistics) can be of different types, for example, the black box approach (one state), the white box approach (multi-state), the simulation of different aspects, and so on. This book has the advantage of bringing together a group of international authors, known for their earthquake-specific approaches, to cover a wide array of these myriad aspects. A variety of topics are presented, including statistical nonparametric and parametric methods, a multi-state system approach, earthquake simulators, post-seismic activity models, time series Markov models with regression, scaling properties and multifractal approaches, selfcorrecting models, the linked stress release model, Markovian arrival models, Poisson-based detection techniques, change point detection techniques on seismicity models, and, finally, semi-Markov models for earthquake forecasting.

Earthquake occurrence modeling is a rapidly developing research area. This book deals with its critical issues, ranging from theoretical advances to practical applications. The introductory chapter outlines state-of-the-art earthquake modeling approaches based on stochastic models. Chapter 2 presents seismogenesis in association with the evolving stress field. Chapters 3 to 5 present earthquake occurrence modeling by means of hidden (semi-)Markov models and discuss associated characteristic measures and relative estimation aspects. Further comparisons, the most important results and our concluding remarks are provided in Chapters 6 and 7.

This special issue of Pure and Applied Geophysics is the second of two volumes containing an augmented collection of papers originating from the Evison Symposium on Seismogenesis and Earthquake Forecasting held in Wellington, New Zealand, in February 2008. The volumes honor Frank Evison's interest in earthquake generation and forecasting. This volume includes descriptions of earthquake forecasting test centers through the Collaboratory for the Study of Earthquake Predictability (CSEP) program and the first results from the Regional Earthquake Likelihood Model (RELM) experiment in California. Other papers discuss methods of testing predictions, in particular by the use of error diagrams. There is discussion of prediction methodologies using seismicity, including an application of the statistical technique of Hidden Markov Models to identify changes in seismicity and a new technique for identifying precursory quiescence. Several papers employ other data besides seismicity, such as geologically determined faults, calculations of stress changes via Coulomb stress modeling, tomographically determined velocity structure, groundwater, crustal deformation, and comparisons of real earthquakes to synthetic seismicity determined from hypothesized earthquake physics. One paper focuses on the prediction of human casualties in the event that a large earthquake occurs anywhere on the globe. The volume will be useful to students and professional researchers who are interested in the earthquake preparation process and in converting that understanding into forecasts of earthquake occurrence.

Earthquake occurrence modeling is a rapidly developing research area. This book deals with its critical issues, ranging from theoretical advances to practical applications. The introductory chapter outlines state-of-the-art earthquake modeling approaches based on stochastic models. Chapter 2 presents seismogenesis in association with the evolving stress field. Chapters 3 to 5 present earthquake occurrence modeling by means of hidden (semi-)Markov models and discuss associated characteristic measures and relative estimation aspects. Further comparisons, the most important results and our concluding remarks are provided in Chapters 6 and 7.

This special issue emerged following the 2013 8th International Statistical Seismology (StatSei8) workshop in Beijing. The articles within have been collected to report on exciting new research in statistical seismology methods and applications; it contains a collection of the newest methods, techniques and results related to statistical analysis of earthquake occurrence and earthquake probability forecasting. The articles within ultimately help to define future research directions in the field. Especially, the rapid development of observation technologies has brought geophysical research into the big-data era. This includes not only non-seismicity geophysical data, such as GPS observation on surface displacement, InSAR observation of the co-seismic deformation, ionospheric observations, etc., but also extended seismological data including slow earthquakes, tremor, and VLF earthquakes. The subject of statistical seismology bridges the gap between physical and statistical models. Many significant achievements have been accomplished during the last several decades, including formulation of conditional intensity models for quantifying seismicity rates, earthquake probability forecasts, and theories related to rigorous testing of forecast models.

This special issue of Pure and Applied Geophysics is one of two volumes containing an augmented collection of papers originating from the Evison Symposium on Seismogenesis and Earthquake Forecasting held in Wellington, New Zealand, in February 2008. The volumes honor Frank Evison's interest in earthquake generation and forecasting. A biography of Frank Evison and a list of his publications is included, as well as review papers and new research papers in the field. The volume includes papers related to Frank's most abiding interest of precursory earthquake swarms. The research contributions cover a range of current forecasting methods such as the Epidemic-Type Aftershock model, the Every Earthquake a precursor According to Scale model, Pattern Informatics, Reverse Tracing of Precursors, stochastic models of elastic rebound, and methods for handling multiple precursors. The methods considered employ a variety of statistical approaches to using previous seismicity to forecast future earthquakes, including regional and global earthquake likelihood models and alarm-type forecasts. The forecast time-frames of interest range from the short time-frame associated with clustering of aftershocks to the long time-frame associated with recurrence of major earthquakes. A recurring theme is the assessment of forecasting performance, whether by likelihood scores, skill scores, error diagrams, or relative operating characteristic tests. The volume will be useful to students and professional researchers who are interested in the earthquake preparation process and in converting that understanding into forecasts of earthquake occurrence.

In the last decade of the 20th century, there has been great progress in the physics of earthquake generation; that is, the introduction of laboratory-based fault constitutive laws as a basic equation governing earthquake rupture, quantitative description of tectonic loading driven by plate motion, and a microscopic approach to study fault zone processes. The fault constitutive law plays the role of an interface between microscopic processes in fault zones and macroscopic processes of a fault system, and the plate motion connects diverse crustal activities with mantle dynamics. An ambitious challenge for us is to develop realistic computer simulation models for the complete earthquake process on the basis of microphysics in fault zones and macro-dynamics in the crust-mantle system. Recent advances in high performance computer technology and numerical simulation methodology are bringing this vision within reach. The book consists of two parts and presents a cross-section of cutting-edge research in the field of computational earthquake physics. Part I includes works on microphysics of rupture and fault constitutive laws, and dynamic rupture, wave propagation and strong ground motion. Part II covers earthquake cycles, crustal deformation, plate dynamics, and seismicity change and its physical interpretation. Topics in Part II range from the 3-D simulations of earthquake generation cycles and interseismic crustal deformation associated with plate subduction to the development of new methods for analyzing geophysical and geodetical data and new simulation algorithms for large amplitude folding and mantle convection with viscoelastic/brittle lithosphere, as well as a theoretical study of accelerated seismic release on heterogeneous faults, simulation of long-range automaton models of earthquakes, and various approaches to earthquake predicition based on underlying physical and/or statistical models for seismicity change.

'Earthquake Occurrence' provides the reader with a review of algorithms applicable for modelling seismicity, such as short-term earthquake clustering and pseudo-periodic long-term behaviour of major earthquakes. The concept of the likelihood ratio of a set of observations under different hypotheses is applied for comparison among various models. In short-term models, known by the term ETAS, the occurrence space and time rate density of earthquakes is modelled as the sum of two terms, one representing the independent or spontaneous events, and the other representing the activity triggered by previous earthquakes. Examples of the application of such algorithms in real cases are also reported. The book also introduces a number of computer codes developed by the authors over decades of seismological research.