Download or read book Empirical Study of the Ground Motion Produced by Earthquakes Originating in the Subduction Zones of Japan and Cascadia microform written by Stella Kay Heenan and published by National Library of Canada = Bibliothèque nationale du Canada. This book was released on 2002 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation Into Earthquake Ground Motion Characteristics in Japan with Emphasis on the 2011 M9 0 Tohoku Earthquake written by Hadi Ghofrani and published by . This book was released on 2012 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this integrated study, ground-motion characteristics of one of the most devastating earthquakes in history, the 11th March 2011 Tohoku-oki earthquake (moment magnitude (M) 9.0), are investigated. The investigation centers on developing empirical and simulated-based ground-motion prediction models for this earthquake. These models allow prediction of expected ground motions from large interface (mega-thrust) earthquakes and estimation of their variability due to variability in input parameters, specifically source characteristics (e.g. slip distributions), propagation path, and site effects. This research work can be divided into two main parts. In the first part, the influence of regional geologic structure, in particular the attenuation effects of seismic wave amplitudes with distance while traveling through a volcanic arc region (forearc versus backarc attenuation), is empirically evaluated using regression analysis of Fourier amplitude spectra (FAS) of well-recorded Japanese events. It is concluded that the separation of forearc and backarc travel paths results in a significant reduction in the standard deviation (sigma) of ground motion predictions (by as much as 0.05 log10 units). The distinction between forearc and backarc attenuation has important implications for hazard analysis in subduction regions. In the second part, the ground-motion characteristics of the 2011 Tohoku earthquake are investigated. First, site response in Japan is thoroughly characterized using thousands of surface and borehole recordings. Site amplification effects are found to be very strong at most sites, often exceeding a factor of five. It is concluded that the large observed groundmotion amplitudes at high frequencies during the Tohoku event are mainly due to the prevalence of shallow-soil conditions in Japan that amplified higher frequencies. A stochastic finite-fault model was used to simulate average response spectra of the Tohoku earthquake, for comparison with observed ground motions. The simulation results show that use of a source model comprised of several rupture asperities produces ground motions that are in good agreement with the observations at both high- and low-frequency ranges, and also provides an accurate description of the temporal characteristics of observed ground motions. The calibrated model for the 2011 Tohoku earthquake can be utilized to predict ground motions for future large events in other regions, such as the Cascadia region of North America, by suitable modifications of the regional attenuation and site parameters.
Download or read book Utilization of Recently Enhanced Simulation Tools and Empirical Ground Motion Databases to Improve Ground Motion Prediction Capabilities written by Khatereh Khodaverdi and published by . This book was released on 2013 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: My research was strongly influenced by ongoing Next Generation Attenuation projects (NGA), which is sponsored by Pacific Earthquake Engineering Research Center (PEER). This far, PEER has sponsored two landmark national projects for developing NGA relationship in active tectonic regions. The result of these two projects will be incorporated into national hazard maps developed by United States Geological Survey (USGS). However, since the national seismic hazard maps include stable continental regions and subduction zones, it is desired to ex- tend those studies to other tectonic regions. NGA-Subduction project has recently been initiated to address Subduction Zones (SZ). For this project, I collaborated with PEER researcher for processing the data of main shock recordings of the Tohoku earthquake. I also analyzed the data to evaluate the implications of this data set with respect to magnitude-, distance-, and site-scaling in existing GMPEs for SZs. The Mw = 9.0 Tohoku-oki Japan earthquake produced approximately 2000 ground motion recordings. We consider 1238 three-component accelerograms corrected with component-specific low-cut filters. The recordings have rupture distances between 44 and 1000km, time-veraged shear wave velocities of Vs30 = 90 to 1900ms−1, and usable response spectral periods of 0.01 to> 10 s. The data support the notion that the increase of ground motions with magnitude saturates at large magnitudes. High frequency ground motions demonstrate faster attenuation with distance in backarc than in forearc regions, which is only captured by one of the four considered ground motion prediction equations for subduction earthquakes. Recordings within 100 km of the fault are used to estimate event terms, which are generally positive (indicating model under-prediction) at short periods and zero or negative (over-prediction) at long periods. We find site amplification to scale minimally with Vs30 at high frequencies, in contrast with other active tectonic regions, but to scale strongly with Vs30 at low frequencies. It is envisioned that the research outlined herein could help earthquake engi- neering community to design infrastructures which are more resistant to earth- quakes by improving ground motion prediction capabilities.
Download or read book Ground Motion and Seismic Site Amplification in Central and Eastern North America and Regional Subduction Zones written by Grace Alexandra Parker and published by . This book was released on 2018 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ground motion intensity measures are used to represent various components of earthquake shaking intensity and frequency content in the form of simple parameters; examples include peak ground acceleration, Arias intensity, and pseudo-spectral acceleration (PSA). Ground motion models (GMMs) are developed to predict these intensity measures as a function of earthquake source, wave propagation path, and local geotechnical site conditions. GMMs are formulated to capture the underlying physics of source processes, wave propagation, and site response, with individual model parameters set based on various combinations of empirical ground motion data analysis and physics-based ground motion simulations. The majority of GMMs are conditioned for hard rock reference sites, with shear wave velocity (VS) = 3000 m/s, or with a time-averaged shear wave velocity in the upper 30 meters of the crust (VS30) = 760 m/s. Additional site amplification models are necessary in order to estimate GMIMs for other site conditions, including weathered rock and soil sites. As shear waves propagate vertically in the near-surface, the conservation of energy dictates that the wave amplitude must increase as the seismic velocity of the medium decreases. This amplification, or the so-called linear site effect, is usually parameterized using VS30, and sometimes site fundamental frequency or depth to bedrock, if available. This thesis has two parts, according to subject matter. The first part of this thesis, consisting of Chapters 2, 3, and 4, focuses on seismic site characterization and site amplification in central and eastern North America (CENA) in the context of the Next Generation Attenuation-East (NGA-East) project. Chapter 2 presents a hybrid geology-slope approach for VS30 estimation that utilized a new and expanded shear-wave velocity (VS) measurement database for CENA. The proxy is conditioned on geologic category from newly considered large-scale geologic maps, the extent of Wisconsin glaciation, sedimentary basin structure, and 30 arc-sec topographic gradient. Nonglaciated sites were found to have a modest natural log dispersion of VS30 ( ln V= 0.36) relative to glaciated sites ( lnV = 0.66), indicating better predictability of VS30 for the former. These findings were used estimate the mean and standard deviation of VS30 for NGA-East recording stations when measurements were not available. Chapter 3 presents empirical linear site amplification models conditioned on time-averaged shear wave velocity in the upper 30 m (VS30) for CENA, developed using a combination of least-squares, mixed effects, and Bayesian techniques. Site amplification is found to scale with VS30 for intermediate to stiff site conditions (VS30 > 300 m/s) in a weaker manner than for active tectonic regions. For stiff sites (> 800 m/s), I find differences in amplification for previously glaciated and non-glaciated regions, with non-glaciated sites having lower amplification. The models account for predictor uncertainty, which does not affect the median model, but decreases model dispersion. Lastly, Chapter 4 presents recommendations for modeling of ergodic site amplification in CENA, based primarily on results from the literature (including the model in Chapter 3), for application in the U.S. Geological Survey national seismic hazard maps. Previously, the maps have used site factors developed using data and simulations for active tectonic regions; however, results from NGA-East demonstrate different levels of site amplification in CENA. The recommended model has three terms, two of which describe linear site amplification: an empirically constrained VS30-scaling term relative to a 760 m/s reference, and a simulation-based term to adjust site amplification from the 760 m/s to the CENA reference of VS = 3000 m/s. The second part of this thesis, consisting of Chapters 5 and 6, focuses on the development of a global GMM and site amplification model with regional adjustment factors for subduction zone regions as a part of the Next Generation Attenuation-Subduction (NGA-Sub) project. Chapter 5 presents global subduction zone GMMs for interface and intraslab events, with regionalized terms for Alaska, Cascadia, Central America. Mexico, Japan, South America, and Taiwan. The near-source saturation model, magnitude-dependent geometrical spreading, and magnitude-scaling break point are constrained using simulations and fault geometry, and the anelastic attenuation, magnitude scaling, and depth scaling terms are constrained empirically. The model is regionalized in the constant, anelastic attenuation, and depth-scaling terms, and the magnitude break-point. When applying the model to a region not considered in the study, we recommend using an appropriate range of epistemic uncertainty that captures regional variation. Chapter 6 presents a subduction-specific site amplification model, meant to be paired with the reference-rock GMM of Chapter 5. This site amplification model for subduction regions accounts for regional differences in VS30-scaling, and re-calibrates a widely used nonlinear site term for active tectonic regions.
Download or read book Ground motion Prediction for Subduction zone Earthquakes written by Fleur Strasser and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Models to predict the ground motion for earthquakes that occur in subductionzones are of great importance for earthquake risk reduction and mitigation in manyparts of the world where there is a significant hazard from large earthquakes alongthe subduction interface and from earthquakes within the subducting slab. Mostexisting ground-motion predictive equations for subduction-zone events areprimarily based on strong-motion recordings from Japan, Cascadia, Mexico, Alaskaand New Zealand. In contrast, few records from South and Central America havebeen included in global predictive equations to date, although a major proportion ofthe seismicity of these regions is related to subduction-zone processes. Thedevelopment of a strong-motion database from subduction-type events in South andCentral America is therefore an important and essential step for ground-motionprediction in these regions as well as other subduction zones in the world. In this project two databases of strong-motion records from subduction-zoneevents along the Peruvian-Chilean and the Central American subduction zones havebeen developed. The Central American database compiled during this study consistsof 554 triaxial ground-motion recordings from both interface and intraslab-typeevents of magnitudes between 5.0?MW?7.7. The database compiled for SouthAmerica consists of 98 triaxial ground-motion recordings from 15 subduction-typeevents of magnitudes 6.3?MW?8.4, recorded at 55 different sites in Peru and Chile, between 1966 and 2007. These datasets have then been used to investigate the extentto which global and regional models for subduction regimes could be applied for theprediction of ground motions from the subduction events in these regions, followinga maximum-likelihood approach. Regional differences in the ground-motionamplitudes amongst the South and Central America subduction zones are examinedand preliminary adjustments to existing equations are made in order to resolve thedifferences between observed ground motions and predictions from these equations. This has led to suggestions for the prediction of ground motions from subductionzoneearthquakes in the South and Central American regions.
Download or read book Ground motion Attenuation Equations for Earthquakes on the Cascadia Subduction Zone written by C. B. Crouse and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Earthquake Motion and Ground Conditions written by 日本建築学会 and published by . This book was released on 1993 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Velocity and Density Models Incorporating the Cascadia Subduction Zone for 3D Earthquake Ground Motion Simulations written by William J. Stephenson and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ground Motion Seismology written by Kazuki Koketsu and published by Springer Nature. This book was released on 2021-01-04 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explains the physics behind seismic ground motions and seismic waves to graduate and upper undergraduate students as well as to professionals. Both seismic ground motions and seismic waves are terms for “shaking” due to earthquakes, but it is common that shaking in the near-field of an earthquake source is called seismic ground motion and in the far-field is called seismic waves. Seismic ground motion is often described by the tensor formula based on the representation theorem, but in this book explicit formulation is emphasized beginning with Augustus Edward Hough Love (1863 – 1940). The book also explains in depth the equations and methods used for analysis and computation of shaking close to an earthquake source. In addition, it provides in detail information and knowledge related to teleseismic body waves, which are frequently used in the analysis of the source of an earthquake.
Download or read book Estimation of Strong Ground Motions from Hypothetical Earthquakes on the Cascadia Subduction Zone Pacific Northwest written by Thomas H. Heaton and published by . This book was released on 1986 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contribution of Post critical Reflections to Ground Motions from Mega thrust Events in the Cascadia Subduction Zone written by Andrew Floyd McNeill and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study the contribution of post-critical reflections at the oceanic Moho to ground motions from mega-thrust events in the Cascadia subduction zone is examined. The hypothesis to be tested is that the Moho post-critical reflection is a primary component of the S-wave-field at large epicentral distances from a subduction zone thrust earthquake. Pseudo 3-D modeling using P-SV pseudo-spectral synthetic seismograms and ray tracing amplitude calculations are employed. Double couple line sources are initiated within a structural model for the Cascadia subduction zone that incorporates an updated Juan de Fuca slab geometry. Areas in which the oceanic Moho post-critical reflection is a primary component of the seismic wave-field are defined as a function of landward extent of rupture for the next mega-thrust event. For rupture extending landward of the down-dip limit of the seismogenic zone, Moho post-critical reflections create a broad maximum in peak ground motions at locations that fall within the Pacific Northwest urban corridor [Portland, Seattle. Vancouver. Victoria]. At these locations, ground motions from sources with dominant frequencies between 1 Hz and 3 Hz can be a factor up to 1.5 greater than those modeled in the absence of the oceanic Moho post-critical reflection. A second maximum is associated with the presence of forearc mantle serpentinization, which affords a route for post-critical reflections at the oceanic Moho to escape upwards toward the Earth's surface rather than being trapped in the oceanic crust wave-guide. The forearc mantle wedge acts to concentrate seismic energy within a narrow region at locations, just landward of major population centers.
Download or read book Contribution of Post critical Reflections to Ground Motions from Mega thrust Events in the Cascadia Subduction Zone written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study the contribution of post-critical reflections at the oceanic Moho to ground motions from mega-thrust events in the Cascadia subduction zone is examined. The hypothesis to be tested is that the Moho post-critical reflection is a primary component of the S-wave-field at large epicentral distances from a subduction zone thrust earthquake. Pseudo 3-D modeling using P-SV pseudo-spectral synthetic seismograms and ray tracing amplitude calculations are employed. Double couple line sources are initiated within a structural model for the Cascadia subduction zone that incorporates an updated Juan de Fuca slab geometry. Areas in which the oceanic Moho post-critical reflection is a primary component of the seismic wave-field are defined as a function of landward extent of rupture for the next mega-thrust event. For rupture extending landward of the down-dip limit of the seismogenic zone, Moho post-critical reflections create a broad maximum in peak ground motions at locations that fall within the Pacific Northwest urban corridor [Portland, Seattle. Vancouver. Victoria]. At these locations, ground motions from sources with dominant frequencies between 1 Hz and 3 Hz can be a factor up to 1.5 greater than those modeled in the absence of the oceanic Moho post-critical reflection. A second maximum is associated with the presence of forearc mantle serpentinization, which affords a route for post-critical reflections at the oceanic Moho to escape upwards toward the Earth's surface rather than being trapped in the oceanic crust wave-guide. The forearc mantle wedge acts to concentrate seismic energy within a narrow region at locations, just landward of major population centers.
Download or read book Transactions of the Seismological Society of Japan written by and published by . This book was released on 1889 with total page 858 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book written by Tōkyō Daigaku. Jishin Kenkyūjo and published by . This book was released on 1958 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Earthquake Ground Motion written by Walter Salazar and published by BoD – Books on Demand. This book was released on 2024-03-06 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthquake Ground Motion is a compilation of ten chapters covering tectonics, seismicity, site effects, tsunamis, infrastructure, and instrumentation. It presents state-of-the-art techniques for retrieving rupture models, seismogenic structures, and validation of focal mechanisms. It also presents macroseismic archiving tools for historical and instrumental earthquakes and the fundamentals of seismic tomography. The book describes the site response analysis in 2D and 3D, considering topographic and soil structure interactions, its incorporation in a seismic hazard analysis, and the impact of earthquakes on the cost of reconstruction. The final sections are devoted to the genesis of earthquakes tsunamis, non-seismic tsunamis, and the new role of gyroscopes in rotational seismology.
Download or read book Characteristics of Subduction Zone Ground Motions with an Emphasis on Latin America written by Victor Contreras and published by . This book was released on 2022 with total page 325 pages. Available in PDF, EPUB and Kindle. Book excerpt: For engineering design and seismic risk assessments, earthquake ground motions are characterized using intensity measures such as peak acceleration or spectral accelerations. Ground motion models (GMMs) estimate statistical distribution of intensity measures given information about the source, source-site path (distance), and site condition. This research pertains to data resources used to develop GMMs for subduction zone regions and adapts a global GMMs to a target region. My initial research developed portions of the NGA-Subduction (NGA-Sub) project database. I worked with other experts to characterize seismic sources and source-to-site paths. The database contains data from 1,880 earthquakes in Alaska, Cascadia, Central America and Mexico, Japan, New Zealand, South America, and Taiwan. Source parameters are related to the earthquake focus and finite fault representations. An important issue was the assignment of event types (intraslab and interface). I developed event type classification procedures that consider hypocenter locations relative to the interface, focal mechanisms, and other factors. The second phase of research involved collaborating with researchers in Mexico to enhance data resources for that region (relative to NGA-Sub) and to use the information to develop a regionally customized GMM. I selected Mexico because it has high seismic hazard, its available GMMs have deficiencies, and it has substantial data from recent events that were not considered in NGA-Sub. The database for Mexico is extended by considering small magnitude (M
Download or read book Bibliography for Topical Studies of Ground Motion Fault Mechanics and Seismic Engineering January 1977 September 1979 written by Kaye M. Walz and published by . This book was released on 1980 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:
