Download or read book An Improved Framework for the Analysis and Dissemination of Seismic Site Characterization Data at Varying Resolutions written by Sean Kamran Ahdi and published by . This book was released on 2018 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most commonly used parameter for representing site conditions for ground motion studies is the time-averaged shear-wave velocity in the upper 30 m, or VS30. While it is preferred to compute VS30 from a directly measured shear-wave velocity (VS) profile using in situ geophysical methods, this information is not always available. One major application of VS30 is the development of ergodic site amplification models, for example as part of ground motion model (GMM) development projects, which require VS30 values for all sites. The first part of this dissertation (Chapters 2-4) addresses the development of proxy-based models for estimation of VS30 for application in subduction zone regions. These procedures are applied at 6433 strong motion recording stations (SMSs) for the NGA-Subduction project, which has the goal of developing GMMs for global subduction zone (SZ) earthquakes. Relatively detailed VS30 prediction models are developed in this thesis for application to the Cascadia SZ in the Pacific Northwest (PNW) region and the Alaska/Aleutian SZs. These are the portions of the United States at greatest risk to seismic hazards from subduction zone earthquakes. In these regions, only 8% of SMSs have measured VS30 values. Proxy-based VS30 statistical models based on in situ measurements were developed from information including surficial geology, topographic gradient (i.e. "slope"), and geomorphic terrain categories. The PNW and Alaska studies result in proxy-based VS30 models based on (1) a hybrid of generalized surficial geologic groups conditioned on topographic slope, and (2) geomorphic terrain categories. With 928 measured VS30 values available in the PNW, statistically robust proxy models were developed, with 18 generally well-populated geology groups assigned logarithmic mean and standard deviation VS30 values, six of which are conditioned on topographic slope, and certain groups reflecting glacial and volcanic geology. Additionally, 13 of a possible 16 terrain classes were well-populated, and these were also assigned VS30 statistical moments. Ultimately, due to strong correlation between the two proxies but an overall lower dispersion of model residuals for the hybrid geology-slope proxy compared to the terrain proxy, use of the hybrid slope-geology proxy model was recommended. For Alaska, a different approach was required, as most geology groups were not well populated. In these cases, VS30 data from the PNW were borrowed for similar geologic groups, residuals analysis for Alaska-only and combined Alaska-PNW group moments were computed, and bias was considered in model prediction. The standard deviations of such groups' model predictions were increased by adding an epistemic uncertainty in the mean to reflect the uncertainty in adopting a proxy for use outside of its original intended region of application. Other SZ regions included in NGA-Subduction project rely on regional VS30 prediction models developed previously or concurrent with this project by others (i.e., Japan, Taiwan, New Zealand, and Chile), or required development of procedures as part of the present work to assign VS30 where regional models are unavailable (i.e., Central America/Mexico and South America outside of Chile). The VS data collection effort for the latter two regions resulted in a general lack of measured VS30 data and proxy information, precluding robust proxy model development. As such, an existing geomorphic terrain class proxy model was borrowed from California, with an additional assigned epistemic uncertainty in the mean to account for increased uncertainty in implementing proxy-based models outside of their original intended region of use. Basin depth terms are also provided for VS profiles that exceed velocity thresholds (e.g., 1.0 or 2.5 km/s) or estimated for regions where 3D seismic velocity models exist (e.g., Cascadia, Japan, New Zealand, and Taiwan). A similar study was undertaken in Iran to populate a site database with VS30 values for a ground motion modeling. Analysis of measured Iranian VS data and comparison of within-group moments for geology and terrain proxies in other regions around the world showed that the Iranian VS30 values did not vary much across different geology groups, a possible sign that the seismic refraction velocity data lacked adequate resolution in the upper 30 m to provide accurate VS30. To mitigate this, a third approach for proxy development was formally developed, in which moments for similar geologic groups were borrowed from the PNW and California, averaged, and used for assignment to Iranian strong motion stations, again with care to factor in inter-regional epistemic uncertainty. This work defined the framework for the assignments of VS30 to the aforementioned data-poor regions of Central America, Mexico, and South America. The second part of this dissertation (Chapter 6) concerns the development of the United States Community VS Profile Database (PDB), a major multi-institutional effort to develop an open-access VS profile database for sites in the United States. The data described herein was collected from diverse sources that include consulting engineering reports from private industry, university research reports and other documents, federal open-file and similar reports, California state agency documents, and reports provided by electric utilities for selected sites. All data are strictly within the public domain, but much of it was for practical purposes inaccessible to most potential users. The VS data sources encompass a wide array of geophysical techniques, are presented in many different formats, and are accompanied by widely divergent supplementary data, including P-wave velocities, geotechnical logs and other data, and penetration test data. A relational database schema of sufficient breadth and flexibility was developed to accommodate this diverse data set. The data are digitized and otherwise prepared in the standardized format specified by the database schema. A web interface (www.uclageo.com/VPDB) was developed for data query, visualization, and download. This resource is anticipated to be useful to geotechnical engineers and engineering seismologists for diverse applications in research and industry practice.

Download or read book Improving Accuracy and Efficiency of Seismic Data Analysis Using Deep Learning written by Harpreet Kaur (Ph. D.) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ultimate goal of seismic data analysis is to retrieve high-resolution information about the subsurface structures. It comprises different steps such as data processing, model building, wave propagation, and imaging, etc. Increasing the resolution and fidelity of the different seismic data analysis tasks eventually leads to an improved understanding of fine-scale structural features. Conventional implementation of these techniques is computationally intensive and expensive, especially with large data sets. Recent advances in neural networks have provided an ability to produce a reasonable result to computationally intensive and time-consuming problems. Deep neural networks are capable of extracting complex nonlinear relationships among variables and have shown efficacy as compared to conventional statistical methods in different areas. A major bottleneck for seismic data analysis is the tradeoff between resolution and efficiency. I address some of these challenges by implementing neural network based frameworks. First, I implement a neural network based workflow for stable and efficient wave extrapolation. Conventionally, it is implemented by finite differences (FD), which have a low computational cost but for larger time-steps may suffer from dispersion artifacts and instabilities. On the other hand, recursive integral time extrapolation (RITE) methods, especially the low-rank extrapolation, which are mixed-domain space-wavenumber operators are designed to make time extrapolation stable and dispersion free in heterogeneous media for large time steps, even beyond the Nyquist limit. They have high spectral accuracy; however, they are expensive as compared to finite-difference extrapolation. The proposed framework overcomes the numerical dispersion of finite-difference wave extrapolation for larger time steps and provides stable and efficient wave extrapolation results equivalent to low-rank wave extrapolation at a significantly reduced cost. Second, I address wave-mode separation and wave-vector decomposition problem to separate a full elastic wavefield into different wavefields corresponding to their respective wave mode. Conventionally, wave mode separation in heterogeneous anisotropic media is done by solving the Christoffel equation in all phase directions for a given set of stiffness-tensor coefficients at each spatial location of the medium, which is a computationally expensive process. I circumvent the need to solve the Christoffel equation at each spatial location by implementing a deep neural network based framework. The proposed approach has high accuracy and efficiency for decoupling the elastic waves, which has been demonstrated using different models of increasing complexity. Third, I propose a hyper-parameter optimization (HPO) workflow for a deep learning framework to simulate boundary conditions for acoustic and elastic wave propagation. The conventional low-order implementation of ABCs and PMLs is challenging for strong anisotropic media. In the tilted transverse isotropic (TTI) case, instabilities may appear in layers with PMLs owing to exponentially increasing modes, which eventually degrades the reverse time migration output. The proposed approach is stable and simulates the effect of higher-order absorbing boundary conditions in strongly anisotropic media, especially TTI media, thus having a great potential for application in reverse time migration. Fourth, I implement a coherent noise attenuation framework, especially for ground-roll noise attenuation using deep learning. Accounting for non-stationary properties of seismic data and associated ground-roll noise, I create training labels using local-time frequency transform (LTF) and regularized non-stationary regression (RNR). The proposed approach automates the ground-roll attenuation process without requiring any manual input in picking the parameters for each shot gather other than in the training data. Lastly, I address the limitation of the iterative methods with conventional implementation for true amplitude imaging. I implement a workflow to correct migration amplitudes by estimating the inverse Hessian operator weights using a neural network based framework. To incorporate non-stationarity in the framework, I condition the input migrated image with different conditioners like the velocity model and source illumination. To correct for the remnant artifacts in the deep neural network (DNN) output, I perform iterative least-squares migration using neural network output as an initial model. The network output is close to the true model and therefore, with fewer iterations, a true-amplitude image with the improved resolution is obtained. The proposed method is robust in areas with poor illumination and can easily be generalized to more-complex cases such as viscoacoustic, elastic, and others. The proposed frameworks are numerically stable with high accuracy and efficiency and are, therefore, desirable for different seismic data analysis tasks. I use synthetic and field data examples of varying complexities in both 2D and 3D to test the practical application and accuracy of the proposed approaches

Download or read book The Seismic Analysis Code written by George Helffrich and published by Cambridge University Press. This book was released on 2013-09-19 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Seismic Analysis Code (SAC) is one of the most widely used analysis packages for regional and teleseismic seismic data. For the first time, this book provides users at introductory and advanced levels with a complete guide to SAC. It leads new users of SAC through the steps of learning basic commands, describes the SAC processing philosophy, and presents its macro language in full, supported throughout with example inputs and outputs from SAC. For more experienced practitioners, the book describes SAC's many hidden features, including advanced graphics aspects, its file structure, how to write independent programs to access and create files, and much more. Tutorial exercises engage users with newly acquired skills, providing data and code to implement the standard methods of teleseismic shear-wave splitting and receiver function analysis. Methodical and authoritative, this is a key resource for researchers and graduate students in global seismology, earthquake seismology and geophysics.

Download or read book Characterization Modeling Monitoring and Remediation of Fractured Rock written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2021-01-29 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fractured rock is the host or foundation for innumerable engineered structures related to energy, water, waste, and transportation. Characterizing, modeling, and monitoring fractured rock sites is critical to the functioning of those infrastructure, as well as to optimizing resource recovery and contaminant management. Characterization, Modeling, Monitoring, and Remediation of Fractured Rock examines the state of practice and state of art in the characterization of fractured rock and the chemical and biological processes related to subsurface contaminant fate and transport. This report examines new developments, knowledge, and approaches to engineering at fractured rock sites since the publication of the 1996 National Research Council report Rock Fractures and Fluid Flow: Contemporary Understanding and Fluid Flow. Fundamental understanding of the physical nature of fractured rock has changed little since 1996, but many new characterization tools have been developed, and there is now greater appreciation for the importance of chemical and biological processes that can occur in the fractured rock environment. The findings of Characterization, Modeling, Monitoring, and Remediation of Fractured Rock can be applied to all types of engineered infrastructure, but especially to engineered repositories for buried or stored waste and to fractured rock sites that have been contaminated as a result of past disposal or other practices. The recommendations of this report are intended to help the practitioner, researcher, and decision maker take a more interdisciplinary approach to engineering in the fractured rock environment. This report describes how existing tools-some only recently developed-can be used to increase the accuracy and reliability of engineering design and management given the interacting forces of nature. With an interdisciplinary approach, it is possible to conceptualize and model the fractured rock environment with acceptable levels of uncertainty and reliability, and to design systems that maximize remediation and long-term performance. Better scientific understanding could inform regulations, policies, and implementation guidelines related to infrastructure development and operations. The recommendations for research and applications to enhance practice of this book make it a valuable resource for students and practitioners in this field.

Download or read book Coding and Decoding Seismic Data written by Luc T. Ikelle and published by Elsevier. This book was released on 2010-03-29 with total page 619 pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently, the acquisition of seismic surveys is performed as a sequential operation in which shots are computed separately, one after the other. This approach is similar to that of multiple-access technology, which is widely used in cellular communications to allow several subscribers to share the same telephone line. The cost of performing various shots simultaneously is almost identical to that of one shot; thus, the savings in time and money expected from using the multishooting approach for computing seismic surveys compared to the current approach are enormous. By using this approach, the long-standing problem of simulating a three-dimensional seismic survey can be reduced to a matter of weeks and not years, as is currently the case. Investigates how to collect, stimulate, and process multishooting data Addresses the improvements in seismic characterization and resolution one can expect from multishooting data Aims to educate the oil and gas exploration and production business of the benefits of multishooting data, and to influence their day-to-day surveying techniques

Download or read book Coding and Decoding Seismic Data written by Luc T. Ikelle and published by Elsevier. This book was released on 2017-12-07 with total page 720 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coding and Decoding Seismic Data: The Concept of Multishooting, Volume One, Second Edition, offers a thorough investigation of modern techniques for collecting, simulating, and processing multishooting data. Currently, the acquisition of seismic surveys is performed as a sequential operation in which shots are computed separately, one after the other. The cost of performing various shots simultaneously is almost identical to that of one shot; thus, the benefits of using the multishooting approach for computing seismic surveys are enormous. By using this approach, the longstanding problem of simulating a three-dimensional seismic survey can be reduced to a matter of weeks. Providing both theoretical and practical explanations of the multishooting approach, including case histories, this book is an essential resource for exploration geophysicists and practicing seismologists. Investigates how to collect, stimulate, and process multishooting data Addresses the improvements in seismic characterization and resolution that can be expected from multishooting data Provides information for the oil and gas exploration and production business that will influence day-to-day surveying techniques Covers robust decoding methods of undetermined mixtures, nonlinear decoding, the use of constraints in decoding processes, and nonlinear imaging of undecoded data Includes access to a companion site with answers to questions posed in the book

Download or read book Seismic Signatures and Analysis of Reflection Data in Anisotropic Media written by I. Tsvankin and published by Elsevier. This book was released on 2001-03-02 with total page 455 pages. Available in PDF, EPUB and Kindle. Book excerpt: Following the breakthrough in the last decade in identifying the key parameters for time and depth imaging in anisotropic media and developing practical methodologies for estimating them from seismic data, this title primarily focuses on the far reaching exploration benefits of anisotropic processing. This volume provides the first comprehensive description of reflection seismic signatures and processing methods in anisotropic media. It identifies the key parameters for time and depth imaging in transversely isotropic media and describes practical methodologies for estimating them from seismic data. Also, it contains a thorough discussion of the important issues of uniqueness and stability of seismic velocity analysis in the presence of anisotropy. The book contains a complete description of anisotropic imaging methods, from the theoretical background to algorithms to implementation issues. Numerous applications to synthetic and field data illustrate the improvements achieved by the anisotropic processing and the possibility of using the estimated anisotropic parameters in lithology discrimination.

Download or read book Advances and Applications of Passive Seismic Source Characterization written by Lei Li and published by Frontiers Media SA. This book was released on 2023-10-09 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Source characterization is a fundamental task of passive seismic monitoring. Spatial-temporal evolution of both, point sources and finite-fault source, provides essential information for timely seismic hazard management and advanced analysis of the seismicity in the monitored areas. In the last few decades, the rise of dense seismic arrays, increase of high-performance computing resources, and development of advanced array-based techniques lead to studies using recorded wavefields in great detail. Full waveform inversion can invert passive seismic source parameters with an iterative framework, which connects the delay-and-sum imaging technique and kernel-based inversion strategy. Moreover, emerging technologies like distributed acoustic sensing and machine learning also have great potential in advancing passive seismic imaging and source characterization. Besides, non-earthquake sources and ambient noise, as unconventional and passive sources, are also undergoing rapid development in infrastructure monitoring and subsurface imaging, due to the emergence of sensitive sensors and modern techniques like seismic interferometry.

Download or read book Multiscale Analysis of Seismic Event Source Parameter Resolution and Characterization written by Jiewen Zhang and published by . This book was released on 2021 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advancements in 1D and 2D Near surface Seismic Site Characterization Using Surface Waves and Full Waveform Inversion written by Michael Benjamin Schutt Yust and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic site characterization is a critical part of understanding earthquake hazards in geotechnical engineering. This is often accomplished through various invasive and non-invasive methods for measuring shear-wave velocity (Vs) in-situ, as it is directly related to small-strain shear modulus. For civil engineering applications, the seismic conditions of the near surface (top 30 m) are of particular interest. Surface wave testing has become the tool of choice for many engineers due to its flexibility, efficiency, and ability to characterize a wide variety of subsurface conditions. Surface wave testing is also particularly well suited to near-surface imaging due to the prevalence of surface waves within the elastic wavefield at shallow depths. Surface wave testing, however, is not without limitations. Inversion of surface wave dispersion data is ill-posed and non-unique, meaning that when it is performed rigorously with full consideration of epistemic uncertainty, a potentially large number of reasonable and different 1D Vs profiles are produced. This presents a challenge of evaluating which profiles should be used for further analysis or design. Additionally, engineers often desire information about the lateral variability of seismic parameters in the subsurface, but the inherently 1D nature of the processing and inversion techniques used in surface wave testing make acquiring this information challenging. Evaluation of lateral variability is generally accomplished through multiple individual 1D surface wave analyses across the site, providing only pseudo-2D information. This also introduces a new challenge: how to collect the large amount of experimental data required for multiple analyses as the efficiency of traditional surface wave acquisition is limited by the need to physically move geophone arrays with limited numbers of sensors. This dissertation discusses these challenges and presents potential solutions through the application of the DeltaVs method, distributed acoustic sensing, and full waveform inversion

Download or read book New Methods for Engineering Site Characterization Using Reflection and Surface Wave Seismic Surveys written by Susit Chaiprakaikeow and published by . This book was released on 2012 with total page 149 pages. Available in PDF, EPUB and Kindle. Book excerpt: PUBLIC ABSTRACT: This study presents two new seismic testing methods for engineering application, a new shallow seismic reflection method and Time Filtered Analysis of Surface Waves (TFASW). Both methods are described in this dissertation. The new shallow seismic reflection was developed to measure reflections at a single point using 2-4 receivers, assuming homogeneous, horizontal layering. Two problems commonly encountered in reflection testing are dealt with in this new method. These problems are: phase shifts between the wave source and ground motion; and, loss of high frequency energy. Using approaches to mitigate these problems significantly improved the shape of measured waveforms. However, none of the sites investigated yielded strong enough reflectors to fully characterize the sites. TFASW is a new surface (Rayleigh) wave method to determine the shear wave velocity profile at soil and rock sites. The method is an improvement over other surface wave seismic methods because digital filters with optimized bandwidths are used to characterize the surface wave dispersion. Successful applications of the TFASW method are shown at three sites.

Download or read book Surface Wave Methods for Near Surface Site Characterization written by Sebastiano Foti and published by CRC Press. This book was released on 2014-08-21 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt: Develop a Greater Understanding of How and Why Surface Wave Testing Works Using examples and case studies directly drawn from the authors’ experience, Surface Wave Methods for Near-Surface Site Characterization addresses both the experimental and theoretical aspects of surface wave propagation in both forward and inverse modeling. This book accents the key facets associated with surface wave testing for near-surface site characterization. It clearly outlines the basic principles, the theoretical framework and the practical implementation of surface wave analysis. In addition, it also describes in detail the equipment and measuring devices, acquisition techniques, signal processing, forward and inverse modeling theories, and testing protocols that form the basis of modern surface wave techniques. Review Examples of Typical Applications for This Geophysical Technique Divided into eight chapters, the book explains surface wave testing principles from data measurement to interpretation. It effectively integrates several examples and case studies illustrating how different ground conditions and geological settings may influence the interpretation of data measurements. The authors accurately describe each phase of testing in addition to the guidelines for correctly performing and interpreting results. They present variants of the test within a consistent framework to facilitate comparisons, and include an in-depth discussion of the uncertainties arising at each stage of surface wave testing. Provides a comprehensive and in-depth treatment of all the steps involved in surface wave testing Discusses surface wave methods and their applications in various geotechnical conditions and geological settings Explains how surface wave measurements can be used to estimate both stiffness and dissipative properties of the ground Addresses the issue of uncertainty, which is often an overlooked problem in surface wave testing Includes examples with comparative analysis using different processing techniques and inversion algorithms Outlines advanced applications of surface wave testing such as joint inversion, underwater investigation, and Love wave analysis Written for geotechnical engineers, engineering seismologists, geophysicists, and researchers, Surface Wave Methods for Near-Surface Site Characterization offers practical guidance, and presents a thorough understanding of the basic concepts.

Download or read book Seismic Reflection Processing for Characterization of a Hazardous Waste Site written by and published by . This book was released on 1997 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic reflection data have been acquired by the Kansas Geological Survey near the Oak Ridge K-25 Plant on the Oak Ridge Reservation, Tennessee, to assist in the selection of ground water monitoring well locations. The data were recorded in uncorrelated format to allow flexibility in enhancement of stacked images. During the summer of 1996, five of the thirteen seismic reflection lines acquired were processed. An unconventional correlation procedure, ''Vibroseis Whitening'' (VSW) (Coruh and Costain, 1983) has been applied to produce improved seismic sections. Refraction statics corrections, which remove the detrimental effect of an irregular weathered layer, have also been utilized to improve the seismic sections. The seismic data were stacked using the velocities obtained from a standard semblance velocity analysis tool. Locations and orientations of faults or fault zones can be interpreted from these stacked sections, and they are in agreement with the interpretations of the surface mapping in the area. This paper concludes that VSW and refraction statics can be important to near-surface swept source seismic data processing.

Download or read book An Integrated Study of Full Wave field Seismic Site Characterization Techniques written by David Craig Pearson and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rock Fractures and Fluid Flow written by National Research Council and published by National Academies Press. This book was released on 1996-08-27 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientific understanding of fluid flow in rock fracturesâ€"a process underlying contemporary earth science problems from the search for petroleum to the controversy over nuclear waste storageâ€"has grown significantly in the past 20 years. This volume presents a comprehensive report on the state of the field, with an interdisciplinary viewpoint, case studies of fracture sites, illustrations, conclusions, and research recommendations. The book addresses these questions: How can fractures that are significant hydraulic conductors be identified, located, and characterized? How do flow and transport occur in fracture systems? How can changes in fracture systems be predicted and controlled? Among other topics, the committee provides a geomechanical understanding of fracture formation, reviews methods for detecting subsurface fractures, and looks at the use of hydraulic and tracer tests to investigate fluid flow. The volume examines the state of conceptual and mathematical modeling, and it provides a useful framework for understanding the complexity of fracture changes that occur during fluid pumping and other engineering practices. With a practical and multidisciplinary outlook, this volume will be welcomed by geologists, petroleum geologists, geoengineers, geophysicists, hydrologists, researchers, educators and students in these fields, and public officials involved in geological projects.

Download or read book Seismic Signatures and Analysis of Reflection Data in Anisotropic Media written by and published by . This book was released on 2012 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Attributes for Prospect Identification and Reservoir Characterization written by Satinder Chopra and published by . This book was released on 2007 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic attributes play a key role in exploration and exploitation of hydrocarbons. In Seismic Attributes for Prospect Identification and Reservoir Characterization (SEG Geophysical Developments No. 11), Satinder Chopra and Kurt J. Marfurt introduce the physical basis, mathematical implementation, and geologic expression of modern volumetric attributes including coherence, dip/azimuth, curvature, amplitude gradients, seismic textures, and spectral decomposition. The authors demonstrate the importance of effective color display and sensitivity to seismic acquisition and processing. Examples from different basins illustrate the attribute expression of tectonic deformation, clastic depositional systems, carbonate depositional systems and diagenesis, drilling hazards, and reservoir characterization. The book is illustrated generously with color figures throughout. "Seismic Attributes" will appeal to seismic interpreters who want to extract more information from data; seismic processors and imagers who want to learn how their efforts impact subtle stratigraphic and fracture plays; sedimentologists, stratigraphers, and structural geologists who use large 3D seismic volumes to interpret their plays within a regional, basinwide context; and reservoir engineers whose work is based on detailed 3D reservoir models. Copublished with EAGE.