Download or read book Earthquake Source Physics on Various Scales written by Adrien Oth and published by Birkhäuser. This book was released on 2014-11-24 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake rupture is a process of remarkable complexity. Over the past few decades, scientists have become aware of its high variability on all scales as well as its wide dynamic range. At the same time, a thorough understanding of the seismic source process is a key element of reliable earthquake ground motion prediction. The present book contains a comprehensive collection of contributions originating from the 2012 ECGS Workshop Earthquake Source Physics on Various Scales, held in Luxembourg. The seventeen articles in this volume cover theoretical and observational aspects of the earthquake source process, ranging from tiny, laboratory-generated M -6 events to the source complexity and radiated energy of the world’s greatest earthquakes. Among other aspects, the papers provide new insights into the relationship of earthquake recurrence time with fault frictional parameters, how the results of lab-based friction experiments relate to observational source studies, and how geometrical source complexity can be quantified. In particular, several papers are devoted to the question whether small and large earthquakes scale self-similarly or if they show differences in their dynamic source characteristics, which is one of the most hotly debated aspects of modern seismology. The volume provides an integrated view of the current state-of-the-art knowledge on the earthquake source process on all scales and will be useful to students and professional researchers who are interested in these phenomena.
Download or read book Living on an Active Earth written by National Research Council and published by National Academies Press. This book was released on 2003-09-22 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: The destructive force of earthquakes has stimulated human inquiry since ancient times, yet the scientific study of earthquakes is a surprisingly recent endeavor. Instrumental recordings of earthquakes were not made until the second half of the 19th century, and the primary mechanism for generating seismic waves was not identified until the beginning of the 20th century. From this recent start, a range of laboratory, field, and theoretical investigations have developed into a vigorous new discipline: the science of earthquakes. As a basic science, it provides a comprehensive understanding of earthquake behavior and related phenomena in the Earth and other terrestrial planets. As an applied science, it provides a knowledge base of great practical value for a global society whose infrastructure is built on the Earth's active crust. This book describes the growth and origins of earthquake science and identifies research and data collection efforts that will strengthen the scientific and social contributions of this exciting new discipline.
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 The Role of Roughness in Earthquake Source Physics written by Yuval Tal (Ph. D.) and published by . This book was released on 2017 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Faults are rough at all scales and can be described as self-affine fractals. This deviation from planarity results in geometric asperities and a locally heterogeneous stress field, which affect the nucleation and propagation of shear rupture. I study this effect numerically at the scale of small earthquakes, in which realistic geometry and friction law parameters can be incorporated in the model. The numerical approach developed in this thesis includes three main features. First, to enable slip that is large relative to the size of the elements near the fault, as well to capture accurately of the variation of normal stress during slip, I implement slip-weakening and rate and state friction laws into the Mortar Finite Element Method, in which non-matching meshes are allowed across the fault and the contacts are continuously updated. Second, the mesh near the fault is refined using hanging nodes to enable accurate representation of the fault geometry. Finally, to model the whole seismic cycle, including a completely spontaneous nucleation process, the method uses variable time stepping with quasi-static and fully dynamic implicit schemes. The developed methodology is used to study the response of rough faults governed by rate and state friction to slow tectonic loading, where, in each simulation, the earthquake sequence includes at least two seismic cycles. With increasing roughness, there is a transition from seismic to aseismic slip behavior, in which the load on the fault is released by more slip events but with lower slip rate, seismic moment, and average static stress drop. We analyze the nucleation process in the fast slip events and show that the roughness introduces local barriers that complicate the nucleation process and result in asymmetric expansions of the rupture, non-monotonic increases in the slip rates on the fault, and the generation of multiple slip pulses. In general, the nucleation length increases with increasing roughness amplitude. However, there are large differences between first slip events in the sequences, where the initial conditions are homogenous, and later events, where the initial stress field and friction conditions are determined by the rupture growth and arrest in previous slip events.
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 Extreme Environmental Events written by and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics of Earthquake Phenomena written by Cargill Gilston Knott and published by . This book was released on 1908 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seismic Motion Lithospheric Structures Earthquake and Volcanic Sources written by Yehuda Ben-Zion and published by Birkhäuser. This book was released on 2012-12-06 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geophysicists use seismic signals to image structures in the Earth's interior, to understand the mechanics of earthquake and volcanic sources, and to estimate their associated hazards. Keiiti Aki developed pioneering quantitative methods for extracting useful information from various portions of observed seismograms and applied these methods to many problems in the above fields. This volume honors Aki's contributions with review papers and results from recent applications by his former students and scientific associates pertaining to topics spawned by his work. Discussed subjects include analytical and numerical techniques for calculating dynamic rupture and radiated seismic waves, stochastic models used in engineering seismology, earthquake and volcanic source processes, seismic tomography, properties of lithospheric structures, analysis of scattered waves, and more. The volume will be useful to students and professional geophysicists alike.
Download or read book Computational Earthquake Physics Simulations Analysis and Infrastructure Part I written by Xiang-chu Yin and published by Springer Science & Business Media. This book was released on 2007-12-03 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first of a two-part work, this volume focuses on microscopic simulation, scaling physics, dynamic rapture and wave propagation, earthquake generation, cycle and seismic pattern. Topics covered range from numerical and theoretical studies of crack propagation, developments in finite difference methods for modeling faults, long time scale simulation of interacting fault systems, and modeling of crustal deformation through to mantle convection.
Download or read book Geocomplexity and the Physics of Earthquakes written by John Rundle and published by American Geophysical Union. This book was released on 2000-01-10 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 120. Earthquakes in urban centers are capable of causing enormous damage. The January 16, 1995 Kobe, Japan earthquake was only a magnitude 6.9 event and yet produced an estimated $200 billion loss. Despite an active earthquake prediction program in Japan, this event was a complete surprise. Similar scenarios are possible in Los Angeles, San Francisco, Seattle, and other urban centers around the Pacific plate boundary. The development of forecast or prediction methodologies for these great damaging earthquakes has been complicated by the fact that the largest events repeat at irregular intervals of hundreds to thousands of years, resulting in a limited historical record that has frustrated phenomenological studies. The papers in this book describe an emerging alternative approach, which is based on a new understanding of earthquake physics arising from the construction and analysis of numerical simulations. With these numerical simulations, earthquake physics now can be investigated in numerical laboratories. Simulation data from numerical experiments can be used to develop theoretical understanding that can be subsequently applied to observed data. These methods have been enabled by the information technology revolution, in which fundamental advances in computing and communications are placing vast computational resources at our disposal.
Download or read book Earthquakes Simulations Sources and Tsunamis written by Kristy F. Tiampo and published by Springer Science & Business Media. This book was released on 2008-11-04 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume attempts to present the current state of seismic research by focusing not only on the modeling of earthquakes and earthquake generated tsunamis, but also on practical comparisons of the resulting phenomenology. In the 1990s, major advancements in seismic research greatly added to the understanding of earthquake fault systems as complex dynamical systems. Large quantities of new and extensive remote sensing data sets provided information on the solid earth.
Download or read book Precise Earthquake Source Parameter Estimation written by Annemarie Susan Baltay and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The question of whether earthquakes, as they increase in size, radiate seismic waves more efficiently is at the core of our understanding of the physics of faulting, as well as our ability to mitigate the effects of strong ground motion. If earthquakes have some intrinsic time or length scale that could be observed or modeled, then seismologists could determine the ultimate size of an earthquake just as it begins to rupture. On the other hand, if earthquakes are self-similar, with no intrinsic time or length scale, than any information learned about the plethora of small and intermediate earthquakes can simply be scaled up to predict parameters, such as ground motion, for larger, more devastating earthquakes. Many studies find that apparent stress and stress drop increase with seismic moment, yet others find an independence of these parameters with moment, obeying self-similar earthquake source physics. Source measurements are controversial due to the inherent difficulty in correcting the radiated waves to negate path and site effects, such as attenuation, scattering or amplification. Independent studies of the same earthquake may find seismic energies that differ by an order of magnitude. Methods to estimate source parameters need to account for these effects, or quantify the range of validity for estimates made with uncorrected seismic records. In this work, I precisely estimate the source parameters radiated seismic energy, apparent stress and stress drop, using both relative spectral measures from empirical Green's functions, and close distance acceleration records. Using relative empirical Green's functions, I can handily negate source and path effects, without explicit consideration of anelastic attenuation. Working with data from 8 sequences of earthquakes in the western US and Honshu, Japan, ranging from M 1.8 to Mw 7.1, I find no clear trend of a dependence of apparent stress or stress drop with moment, finding a constant scaled energy, ER/Mo of 3.5x10-5, or apparent stress of ~ 1 MPa, to fit the data well. The average Brune stress drop for these data is ~5 MPa. By using many stations and relative measures, I statistically show self-similar earthquake scaling. However, there are anomalous enervated and energetic events that show individual departure from the overall trend, representing the true variability in earthquake source parameters. I revisit the aRMS stress drop using recent broadband stations and strong motion accelerometers. The aRMS stress drop samples an inherently different portion of the earthquake spectrum than the Brune stress drop, and can be directly related to PGA and hence high-frequency ground motion. While the aRMS stress drop is much simpler and faster to measure, it does not model attenuation, and hence suffers from loss of signal at distances> ~20 km. At close stations, and for large earthquakes, the aRMS stress drop values are very similar to those of the Brune stress drop, yet with reduced error base on corner frequency uncertainty. That the aRMS[not] method yields stable stress drops supports the assumptions behind the formulation: that earthquake acceleration records can be considered random, band-limited, white Gaussian noise, and overall, a self-similar earthquake model. The last portion of this work focuses on five great earthquakes, Mw> 8.5, over the past 7 years. Because they are so rare, seismologists don't have much information about these devastating events. Understanding how they relate to smaller earthquakes will aid in hazard mitigation. I estimate the radiated seismic energy and apparent stress, using a novel, teleseismic empirical Green's function deconvolution. At near distances, great earthquake are too big to model, as effects from one end of the rupture will interfere with those from other parts, and local recordings are often saturated. But at far distances, ~3000 km -- 9000 km, I show that moderate earthquakes, Mw 6.5 -- 7.5 can be used as Green's functions, and are used to correct the mainshocks from path and site effects. Use of several different eGf earthquakes demonstrates the limitations on the method, but also increases the precision of the energy estimates. I find that both P and S waves give consistent energy estimates when using eGf events. Azimuthal dependence of radiated energy indicates expected rupture directivity, and can be modeled using Haskell line sources to understand the rupture process.
Download or read book Living on an Active Earth written by National Research Council and published by National Academies Press. This book was released on 2003-08-22 with total page 430 pages. Available in PDF, EPUB and Kindle. Book excerpt: The destructive force of earthquakes has stimulated human inquiry since ancient times, yet the scientific study of earthquakes is a surprisingly recent endeavor. Instrumental recordings of earthquakes were not made until the second half of the 19th century, and the primary mechanism for generating seismic waves was not identified until the beginning of the 20th century. From this recent start, a range of laboratory, field, and theoretical investigations have developed into a vigorous new discipline: the science of earthquakes. As a basic science, it provides a comprehensive understanding of earthquake behavior and related phenomena in the Earth and other terrestrial planets. As an applied science, it provides a knowledge base of great practical value for a global society whose infrastructure is built on the Earth's active crust. This book describes the growth and origins of earthquake science and identifies research and data collection efforts that will strengthen the scientific and social contributions of this exciting new discipline.
Download or read book Elementary Seismology written by Charles Richter and published by . This book was released on 1958 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Physics of Rock Failure and Earthquakes written by Mitiyasu Ohnaka and published by Cambridge University Press. This book was released on 2013-04-11 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite significant advances in the understanding of earthquake generation processes and derivation of underlying physical laws, controversy remains regarding the constitutive law for earthquake ruptures and how it should be formulated. Laboratory experiments are necessary to obtain high-resolution measurements that allow the physical nature of shear rupture processes to be deduced, and to resolve the controversy. This important book provides a deeper understanding of earthquake processes from nucleation to their dynamic propagation. Its key focus is a deductive approach based on laboratory-derived physical laws and formulae, such as a unifying constitutive law, a constitutive scaling law, and a physical model of shear rupture nucleation. Topics covered include: the fundamentals of rock failure physics, earthquake generation processes, physical scale dependence, and large-earthquake generation cycles. Designed for researchers and professionals in earthquake seismology, rock failure physics, geology and earthquake engineering, it is also a valuable reference for graduate students.
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 Seismic Wave Propagation and Scattering in the Heterogeneous Earth Second Edition written by Haruo Sato and published by Springer Science & Business Media. This book was released on 2012-03-08 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic waves - generated both by natural earthquakes and by man-made sources - have produced an enormous amount of information about the Earth's interior. In classical seismology, the Earth is modeled as a sequence of uniform horizontal layers (or spherical shells) having different elastic properties and one determines these properties from travel times and dispersion of seismic waves. The Earth, however, is not made of horizontally uniform layers, and classic seismic methods can take large-scale inhomogeneities into account. Smaller-scale irregularities, on the other hand, require other methods. Observations of continuous wave trains that follow classic direct S waves, known as coda waves, have shown that there are heterogeneities of random size scattered randomly throughout the layers of the classic seismic model. This book focuses on recent developments in the area of seismic wave propagation and scattering through the randomly heterogeneous structure of the Earth, with emphasis on the lithosphere. The presentation combines information from many sources to present a coherent introduction to the theory of scattering in acoustic and elastic materials and includes analyses of observations using the theoretical methods developed. The second edition especially includes new observational facts such as the spatial variation of medium inhomogeneities and the temporal change in scattering characteristics and recent theoretical developments in the envelope synthesis in random media for the last ten years. Mathematics is thoroughly rewritten for improving the readability. Written for advanced undergraduates or beginning graduate students of geophysics or planetary sciences, this book should also be of interest to civil engineers, seismologists, acoustical engineers, and others interested in wave propagation through inhomogeneous elastic media.
