Download or read book Stress Modulation of Earthquakes written by Christopher W. Johnson and published by . This book was released on 2017 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Decomposing fault mechanical processes advances our understanding of active fault systems and properties of the lithosphere, thereby increasing the effectiveness of seismic hazard assessment and preventative measures implemented in urban centers. Along plate boundaries earthquakes are inevitable as tectonic forces reshape the Earth's surface. Earthquakes, faulting, and surface displacements are related systems that require multidisciplinary approaches to characterize deformation in the lithosphere. Modern geodetic instrumentation can resolve displacements to millimeter precision and provide valuable insight into secular deformation in near real-time. The expansion of permanent seismic networks as well as temporary deployments allow unprecedented detection of microseismic events that image fault interfaces and fracture networks in the crust. The research presented in this dissertation is at the intersection of seismology and geodesy to study the Earth's response to transient deformation and explores research questions focusing on earthquake triggering, induced seismicity, and seasonal loading while utilizing seismic data, geodetic data, and modeling tools. The focus is to quantify stress changes in the crust, explore seismicity rate variations and migration patterns, and model crustal deformation in order to characterize the evolving state of stress on faults and the migration of fluids in the crust. The collection of problems investigated all investigate the question: Why do earthquakes nucleate following a low magnitude stress perturbation? Answers to this question are fundamental to understanding the time dependent failure processes of the lithosphere. Dynamic triggering is the interaction of faults and triggering of earthquakes represents stress transferring from one system to another, at both local and remote distances [Freed, 2005]. The passage of teleseismic surface waves from the largest earthquakes produce dynamic stress fields and provides a natural laboratory to explore the causal relationship between low-amplitude stress changes and dynamically triggered events. Interestingly, observations of dynamically triggered M≥5.5 earthquakes are absent in the seismic records [Johnson et al., 2015; Parsons and Velasco, 2011], which invokes questions regarding whether or not large magnitude events can be dynamically triggered. Emerging results in the literature indicate undocumented M≥5.5 events at near to intermediate distances are dynamically triggered during the passage of surface waves but are undetected by automated networks [Fan and Shearer, 2016]. This raises new questions about the amplitude and duration of dynamic stressing for large magnitude events. I used 35-years of global seismicity and find that large event rate increases only occur following a delay from the transient load, suggesting aseismic processes are associated with large magnitude triggered events. To extend this finding I investigated three cases of large magnitude delayed dynamic triggering following the M8.6 2012 Indian Ocean earthquake [Pollitz et al., 2012] by producing microseismicity catalogs and modeling the transient stresses. The results indicate immediate triggering of microseismic events that hours later culminate into a large magnitude event and support the notion that large magnitude events are triggerable by transient loading, but seismic and aseismic processes (e.g. induced creep or fluid mobilization) are contributing to the nucleation process. Open questions remain concerning the source of a nucleation delay period following a stress perturbation that require both geodetic and seismic observations to constrain the source of delayed dynamic triggering and possibly provide insight into a precursory nucleation phase Induced seismicity has gained much attention in the past 5 years as earthquake rates in regions of low tectonic strain accumulation accelerate to unprecedented levels [Ellsworth, 2013]. The source of the seismicity is attributed to shallow fluid injection associated with energy production. As hydrocarbon extraction continues to increase in the U.S. the deformation and induced seismicity from wastewater injection is providing new avenues to explore crustal properties. The large magnitude events associated with regions of high rate injection support the notion that the crust is critically stressed. Seismic data in these areas provides the opportunity to delineate fault structures in the crust using precise earthquake locations. To augment the studies of transient loading cycles I investigated induced seismicity at The Geysers geothermal field in northern California. Using high-resolution hypocenter data I implement an epidemic type aftershock sequence (ETAS) model to develop seismicity rate time series in the active geothermal field and characterize the migration of fluids from high volume water injection. Subtle stress changes induced by thermo- and poroelastic strains trigger seismicity for ~5 months after peak injection at depths ~3 km below the main injection interval. This suggests vertical migration paths are maintained in the geothermal field that allows fluid propagation on annual time scales. Fully describing the migration pattern of fluids in the crust and the associated stresses are applicable to tectonic related faulting and triggered seismic activity. Seasonal hydrological loading is a source of annual periodic transient deformation that is ideal for investigating the modulation of seismicity. The initial step in exploring the modulation of seismicity is to validate that a significant annual period does exist in California earthquake records. The periodicity results [Dutilleul et al., 2015] motivate continued investigation of seismically active regions that experience significant seasonal mass loading, i.e. high precipitation and snowfall rates, to quantify the magnitude of seasonal stress changes and possible correlation with seismicity modulation. The implication of this research addresses questions concerning the strength and state of stress on faults. High-resolution water storage time series throughout California are developed using continuous GPS records. The results allow an estimation of the stress changes induced by hydrological loading, which is combined with a detailed focal mechanism analysis to characterize the modulation of seismicity. The hydrologic loading is augmented with the contribution of additional deformation sources (e.g. tidal, atmosphere, and temperature) and find that annual stress changes of ~5 kPa are modulating seismicity, most notably on dip-slip structures. These observations suggest that mechanical differences exist between the vertically dipping strike-slip faults and the shallowly dipping oblique structures in California. When comparing all the annual loading cycles it is evident that future studies incorporate all the sources of solid Earth deformation to fully describe the stresses realized on fault systems that respond to seasonal loads.
Download or read book Best Practices in Physics based Fault Rupture Models for Seismic Hazard Assessment of Nuclear Installations written by Luis A. Dalguer and published by Birkhäuser. This book was released on 2017-12-20 with total page 333 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume collects several extended articles from the first workshop on Best Practices in Physics-based Fault Rupture Models for Seismic Hazard Assessment of Nuclear Installations (BestPSHANI). Held in 2015, the workshop was organized by the IAEA to disseminate the use of physics-based fault-rupture models for ground motion prediction in seismic hazard assessments (SHA). The book also presents a number of new contributions on topics ranging from the seismological aspects of earthquake cycle simulations for source scaling evaluation, seismic source characterization, source inversion and physics-based ground motion modeling to engineering applications of simulated ground motion for the analysis of seismic response of structures. Further, it includes papers describing current practices for assessing seismic hazard in terms of nuclear safety in low seismicity areas, and proposals for physics-based hazard assessment for critical structures near large earthquakes. The papers validate and verify the models by comparing synthetic results with observed data and empirical models. The book is a valuable resource for scientists, engineers, students and practitioners involved in all aspects of SHA.
Download or read book The Mechanics of Earthquakes and Faulting written by Christopher H. Scholz and published by Cambridge University Press. This book was released on 2002-05-02 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our understanding of earthquakes and faulting processes has developed significantly since publication of the successful first edition of this book in 1990. This revised edition, first published in 2002, was therefore thoroughly up-dated whilst maintaining and developing the two major themes of the first edition. The first of these themes is the connection between fault and earthquake mechanics, including fault scaling laws, the nature of fault populations, and how these result from the processes of fault growth and interaction. The second major theme is the central role of the rate-state friction laws in earthquake mechanics, which provide a unifying framework within which a wide range of faulting phenomena can be interpreted. With the inclusion of two chapters explaining brittle fracture and rock friction from first principles, this book is written at a level which will appeal to graduate students and research scientists in the fields of seismology, physics, geology, geodesy and rock mechanics.
Download or read book The Mechanics of Earthquakes and Faulting written by Christopher H. Scholz and published by Cambridge University Press. This book was released on 2002-05-02 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our understanding of earthquakes and faulting processes has developed significantly since publication of the successful first edition of this book in 1990. This revised edition, first published in 2002, was therefore thoroughly up-dated whilst maintaining and developing the two major themes of the first edition. The first of these themes is the connection between fault and earthquake mechanics, including fault scaling laws, the nature of fault populations, and how these result from the processes of fault growth and interaction. The second major theme is the central role of the rate-state friction laws in earthquake mechanics, which provide a unifying framework within which a wide range of faulting phenomena can be interpreted. With the inclusion of two chapters explaining brittle fracture and rock friction from first principles, this book is written at a level which will appeal to graduate students and research scientists in the fields of seismology, physics, geology, geodesy and rock mechanics.
Download or read book Earthquake Source Mechanics written by Shamita Das and published by American Geophysical Union. This book was released on 1986 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rock Stress and Earthquakes written by Furen Xie and published by CRC Press. This book was released on 2010-07-29 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The evaluation of in-situ rock stress is not only important in the exploration and engineering involving rock masses for mining, hydropower, tunneling, oil and gas production, and stone quarrying, but also in the geodynamics and earthquake prediction. The methods of determining these stresses for shallow crust in the engineering practice, including hydraulic fracture method, stress relief method, and acoustic emission method, have not developed substantially to satisfy the increasing utilization of rock masses. The geophysical methods for stresses determination of deep crust only determine the stress fields of deep crust qualitatively. Contributed by a group of leading experts from engineering and geophysical community, Rock Stress and Earthquakes addresses new developments in numerical modeling and advanced measuring techniques in engineering practices, and build new connections between traditional and geophysical methods, which will both benefit earthquake prediction based on the concept of the crustal stresses. Rock Stress and Earthquakes reflects the developments in this area, covering measuring techniques, interpretation methods, and the application of in-situ stress in engineering practice and geophysics, and is of interest to academics and engineers in rock mechanics, geophysics, geology, and seismology.
Download or read book Earthquakes and Water written by Chi-yuen Wang and published by Springer. This book was released on 2010-01-11 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the graduate course in Earthquake Hydrology at Berkeley University, this text introduces the basic materials, provides a comprehensive overview of the field to interested readers and beginning researchers, and acts as a convenient reference point.
Download or read book Models of Stress Changes Induced by Earthquakes and Their Relationships to Changes in the Spatial Distribution of Seismicity written by Susanna J. Gross and published by . This book was released on 1993 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theory of Earthquake Premonitory and Fracture Processes written by Roman Teisseyre and published by . This book was released on 1995 with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Earthquake Processes Physical Modelling Numerical Simulation and Data Analysis Part I written by Mitsuhiro Matsu'ura and published by Birkhäuser. This book was released on 2012-12-06 with total page 389 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 covered in Part I range from the microscopic simulation and laboratory studies of rock fracture and the underlying mechanism for nucleation and catastrophic failure to the development of theoretical models of frictional behaviors of faults; as well as the simulation studies of dynamic rupture processes and seismic wave propagation in a 3-D heterogeneous medium, to the case studies of strong ground motions from the 1999 Chi-Chi earthquake and seismic hazard estimation for Cascadian subduction zone earthquakes.
Download or read book Probabilistic Seismic Hazard Assessment for the State of California written by and published by . This book was released on 1996 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rock Stress and Earthquakes written by Furen Xie and published by CRC Press. This book was released on 2010-07-29 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt: The evaluation of in-situ rock stress is not only important in the exploration and engineering involving rock masses for mining, hydropower, tunneling, oil and gas production, and stone quarrying, but also in the geodynamics and earthquake prediction. The methods of determining these stresses for shallow crust in the engineering practice, including hydraulic fracture method, stress relief method, and acoustic emission method, have not developed substantially to satisfy the increasing utilization of rock masses. The geophysical methods for stresses determination of deep crust only determine the stress fields of deep crust qualitatively. Contributed by a group of leading experts from engineering and geophysical community, Rock Stress and Earthquakes addresses new developments in numerical modeling and advanced measuring techniques in engineering practices, and build new connections between traditional and geophysical methods, which will both benefit earthquake prediction based on the concept of the crustal stresses. Rock Stress and Earthquakes reflects the developments in this area, covering measuring techniques, interpretation methods, and the application of in-situ stress in engineering practice and geophysics, and is of interest to academics and engineers in rock mechanics, geophysics, geology, and seismology.
Download or read book Earthquake Processes Physical Modelling Numerical Simulation and Data Analysis Part II written by Mitsuhiro Matsu'ura and published by Birkhäuser. This book was released on 2012-12-06 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Principles of Earthquake Source Mechanics written by B. V. Kostrov and published by Cambridge University Press. This book was released on 1988 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Kostrov and Das present a general theoretical model summarizing our current knowledge of fracture mechanics as applied to earthquakes and earthquake source processes. Part I explains continuum and fracture mechanics, providing the reader with some background and context. Part II continues with a discussion of the inverse problem of earthquake source theory and a description of the seismic moment tensor. Part III presents specific earthquake source models. Although data processing and acquisition techniques are discussed only in simplified form for illustrative purposes, the material in this book will aid in better orienting and developing these techniques. The aim of this book is to explore the phenomena underlying earthquake fracture and present a general theoretical model for earthquake source processes.
Download or read book Fluid Induced Seismicity written by S. A. Shapiro and published by Cambridge University Press. This book was released on 2015-04-23 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a quantitative introduction to the physics, application, interpretation, and hazard aspects of fluid-induced seismicity, focussing on spatio-temporal dynamics. Including many real data examples, this is a valuable reference for researchers and graduate students of geophysics, geomechanics and petrophysics, and a practical guide for petroleum geoscientists and engineers.
Download or read book Representation of Irregular Stress Time Histories by Equivalent Uniform Stress Series in Liquefaction Analyses written by Harry Bolton Seed and published by . This book was released on 1975 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Source Mechanisms of Earthquakes written by Agustín Udías Vallina and published by Cambridge University Press. This book was released on 2014-04-24 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: An innovative new approach to studying earthquake source mechanisms, combining theory and observation, for graduate students, researchers and seismology professionals.
