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Sample records for 3d seismic model

  1. Parallel 3-D viscoelastic finite difference seismic modelling

    NASA Astrophysics Data System (ADS)

    Bohlen, Thomas

    2002-10-01

    Computational power has advanced to a state where we can begin to perform wavefield simulations for realistic (complex) 3-D earth models at frequencies of interest to both seismologists and engineers. On serial platforms, however, 3-D calculations are still limited to small grid sizes and short seismic wave traveltimes. To make use of the efficiency of network computers a parallel 3-D viscoelastic finite difference (FD) code is implemented which allows to distribute the work on several PCs or workstations connected via standard ethernet in an in-house network. By using the portable message passing interface standard (MPI) for the communication between processors, running times can be reduced and grid sizes can be increased significantly. Furthermore, the code shows good performance on massive parallel supercomputers which makes the computation of very large grids feasible. This implementation greatly expands the applicability of the 3-D elastic/viscoelastic finite-difference modelling technique by providing an efficient, portable and practical C-program.

  2. Northern California Seismic Attenuation: 3-D Qp and Qs models

    NASA Astrophysics Data System (ADS)

    Eberhart-Phillips, D. M.

    2015-12-01

    The northern California crust exhibits a wide range of rock types and deformation processes which produce pronounced heterogeneity in regional attenuation. Using local earthquakes, 3-D Qp and Qs crustal models have been obtained for this region which includes the San Andreas fault system, the Central Valley, the Sierra Nevada batholith, and the Mendocino subduction volcanic system. Path attenuation t* values were determined from P and S spectra of 959 spatially distributed earthquakes, magnitude 2.5-6.0 from 2005-2014, using 1254 stations from NCEDC networks and IRIS Mendocino and Sierra Nevada temporary arrays. The t* data were used in Q inversions, using existing hypocenters and 3-D velocity models, with basic 10-km node spacing. The uneven data coverage was accounted for with linking of nodes into larger areas in order to provide useful Q images across the 3-D volume. The results at shallow depth (< 2 km) show very low Q in the Sacramento Delta, the Eureka area, and parts of the Bay Area. In the brittle crust, fault zones that have high seismicity exhibit low Q. In the lower crust, low Q is observed along fault zones that have large cumulative displacement and have experienced grain size reduction. Underlying active volcanic areas, low Q features are apparent below 20-km depth. Moderately high Q is associated with igneous rocks of the Sierra Nevada and Salinian block, while the Franciscan subduction complex shows moderately low Q. The most prominent high Q feature is related to the Great Valley Ophiolite.

  3. The USGS 3D Seismic Velocity Model for Northern California

    NASA Astrophysics Data System (ADS)

    Brocher, T. M.; Aagaard, B.; Simpson, R. W.; Jachens, R. C.

    2006-12-01

    We present a new regional 3D seismic velocity model for Northern California for use in strong motion simulations of the 1906 San Francisco and other earthquakes. The model includes compressional-wave velocity (Vp), shear-wave velocity (Vs), density, and intrinsic attenuation (Qp, Qs). These properties were assigned for each rock type in a 3D geologic model derived from surface outcrops, boreholes, gravity and magnetic data, and seismic reflection, refraction, and tomography studies. A detailed description of the model, USGS Bay Area Velocity Model 05.1.0, is available online [http://www.sf06simulation.org/geology/velocitymodel]. For ground motion simulations Vs and Qs are more important parameters than Vp and Qp because the strongest ground motions are generated chiefly by shear and surface wave arrivals. Because Vp data are more common than Vs data, however, we first developed Vp versus depth relations for each rock type and then converted these to Vs versus depth relations. For the most important rock types in Northern California we compiled measurements of Vp versus depth using borehole logs, laboratory measurements on hand samples, seismic refraction profiles, and tomography models. These rock types include Salinian and Sierran granitic rocks, metagraywackes and greenstones of the Franciscan Complex, Tertiary and Mesozoic sedimentary and volcanic rocks, and Quaternary and Holocene deposits (Brocher, USGS OFR 05-1317, 2005). Vp versus depth curves were converted to Vs versus depth curves using new empirical nonlinear relations between Vs and Vp (Brocher, BSSA, 2005). These relations, showing that Poisson's ratio is a nonlinear function of Vp, were similarly based on compilations of diverse Vs and Vp measurements on a large suite of rock types, mainly from California and the Pacific Northwest. The model is distributed in a discretized form with routines to query the model using C++, C, and Fortran 77 programming languages. The geologic model was discretized at

  4. Assessing a 3D smoothed seismicity model of induced earthquakes

    NASA Astrophysics Data System (ADS)

    Zechar, Jeremy; Király, Eszter; Gischig, Valentin; Wiemer, Stefan

    2016-04-01

    As more energy exploration and extraction efforts cause earthquakes, it becomes increasingly important to control induced seismicity. Risk management schemes must be improved and should ultimately be based on near-real-time forecasting systems. With this goal in mind, we propose a test bench to evaluate models of induced seismicity based on metrics developed by the CSEP community. To illustrate the test bench, we consider a model based on the so-called seismogenic index and a rate decay; to produce three-dimensional forecasts, we smooth past earthquakes in space and time. We explore four variants of this model using the Basel 2006 and Soultz-sous-Forêts 2004 datasets to make short-term forecasts, test their consistency, and rank the model variants. Our results suggest that such a smoothed seismicity model is useful for forecasting induced seismicity within three days, and giving more weight to recent events improves forecast performance. Moreover, the location of the largest induced earthquake is forecast well by this model. Despite the good spatial performance, the model does not estimate the seismicity rate well: it frequently overestimates during stimulation and during the early post-stimulation period, and it systematically underestimates around shut-in. In this presentation, we also describe a robust estimate of information gain, a modification that can also benefit forecast experiments involving tectonic earthquakes.

  5. 3-D Seismic Interpretation

    NASA Astrophysics Data System (ADS)

    Moore, Gregory F.

    2009-05-01

    This volume is a brief introduction aimed at those who wish to gain a basic and relatively quick understanding of the interpretation of three-dimensional (3-D) seismic reflection data. The book is well written, clearly illustrated, and easy to follow. Enough elementary mathematics are presented for a basic understanding of seismic methods, but more complex mathematical derivations are avoided. References are listed for readers interested in more advanced explanations. After a brief introduction, the book logically begins with a succinct chapter on modern 3-D seismic data acquisition and processing. Standard 3-D acquisition methods are presented, and an appendix expands on more recent acquisition techniques, such as multiple-azimuth and wide-azimuth acquisition. Although this chapter covers the basics of standard time processing quite well, there is only a single sentence about prestack depth imaging, and anisotropic processing is not mentioned at all, even though both techniques are now becoming standard.

  6. Intraplate Seismicity and Lithospheric Strength as Inferred from 3D Seismic Models

    NASA Astrophysics Data System (ADS)

    Mooney, W. D.; Pollitz, F. F.; Ritsema, J.

    2014-12-01

    Focal mechanism studies and other stress indicators indicate that intraplate earthquakes in central and eastern North America are consistent with an ENE-WSW compressive stress field that acts on existing faults. Here we argue that either locally thinned lithosphere (as beneath the Reelfoot Rift, central US) or regional lithospheric thinning (as beneath the edge of the North American craton or the rifted continental margin) constitutes zones of relatively low lithospheric strength where crustal strain accumulates. We use seismic surface waves to determine the 3D shear-wave seismic velocity structure of the lithosphere, and find that the Reelfoot Rift is underlain by a zone with low mantle seismic velocities that extends to at least 200 km depth. Thus, the Reelfoot Rift, which hosts the New Madrid Seismic Zone, is unique among North American paleo-rifts in term of the properties in the mantle. We hypothesize that this low-velocity mantle volume is weaker than its surroundings and that the Reelfoot Rift consequently has relatively lower elastic plate thickness that would tend to concentrate tectonic stress within this zone. On a continental scale, the 3D velocity model clearly identifies an approximately 220-km-thick, high seismic velocity lithospheric root beneath the North America craton which has a low rate of crustal seismicity and very few events with Mw≥6. We attribute the relatively aseismic nature of the craton to dry, cold conditions within the cratonic lower crust and mantle lithosphere. Conversely, we find that a high proportion of intraplate events are concentrated around the pronounced lateral gradient in lithospheric thickness that surrounds the craton. We attribute this observation to a lateral decrease in lithospheric strength at the edge of the North American craton. This relationship between intraplate seismicity and lithospheric properties is apparent in maps that compare regional and continental lithospheric thickness with crustal seismicity. We

  7. 3D Modelling of Seismically Active Parts of Underground Faults via Seismic Data Mining

    NASA Astrophysics Data System (ADS)

    Frantzeskakis, Theofanis; Konstantaras, Anthony

    2015-04-01

    During the last few years rapid steps have been taken towards drilling for oil in the western Mediterranean sea. Since most of the countries in the region benefit mainly from tourism and considering that the Mediterranean is a closed sea only replenishing its water once every ninety years careful measures are being taken to ensure safe drilling. In that concept this research work attempts to derive a three dimensional model of the seismically active parts of the underlying underground faults in areas of petroleum interest. For that purpose seismic spatio-temporal clustering has been applied to seismic data to identify potential distinct seismic regions in the area of interest. Results have been coalesced with two dimensional maps of underground faults from past surveys and seismic epicentres, having followed careful reallocation processing, have been used to provide information regarding the vertical extent of multiple underground faults in the region of interest. The end product is a three dimensional map of the possible underground location and extent of the seismically active parts of underground faults. Indexing terms: underground faults modelling, seismic data mining, 3D visualisation, active seismic source mapping, seismic hazard evaluation, dangerous phenomena modelling Acknowledgment This research work is supported by the ESPA Operational Programme, Education and Life Long Learning, Students Practical Placement Initiative. References [1] Alves, T.M., Kokinou, E. and Zodiatis, G.: 'A three-step model to assess shoreline and offshore susceptibility to oil spills: The South Aegean (Crete) as an analogue for confined marine basins', Marine Pollution Bulletin, In Press, 2014 [2] Ciappa, A., Costabile, S.: 'Oil spill hazard assessment using a reverse trajectory method for the Egadi marine protected area (Central Mediterranean Sea)', Marine Pollution Bulletin, vol. 84 (1-2), pp. 44-55, 2014 [3] Ganas, A., Karastathis, V., Moshou, A., Valkaniotis, S., Mouzakiotis

  8. Understanding North Texas Seismicity: A Joint Analysis of Seismic Data and 3D Pore Pressure Modeling

    NASA Astrophysics Data System (ADS)

    DeShon, H. R.; Hornbach, M. J.; Ellsworth, W. L.; Oldham, H. R.; Hayward, C.; Stump, B. W.; Frohlich, C.; Olson, J. E.; Luetgert, J. H.

    2014-12-01

    In November 2013, a series of earthquakes began along a mapped ancient fault system near Azle, Texas. The Azle events are the third felt earthquake sequence in the Fort Worth (Barnett Shale) Basin since 2008, and several production and injection wells in the area are drilled to depths near the recent seismic activity. Understanding if and/or how injection and removal of fluids in the crystalline crust reactivates faults have important implications for seismology, the energy industry, and society. We assessed whether the Azle earthquakes were induced using a joint analysis of the earthquake data, subsurface geology and fault structure, and 3D pore pressure modeling. Using a 12-station temporary seismic deployment, we have recorded and located >300 events large enough to be recorded on multiple stations and 1000s of events during periods of swarm activity. High-resolution locations and focal mechanisms indicate that events occurred on NE-SW trending, steeply dipping normal faults associated with the southern end of the Newark East Fault Zone with hypocenters between 2-8 km depth. We considered multiple causes that might have changed stress along this system. Earthquakes resulting from natural processes, though perhaps unlikely in this historically inactive region, can be neither ruled out nor confirmed due to lack of information on the natural stress state of these faults. Analysis of lake and groundwater variations near Azle showed that no significant stress changes occurred prior to or during the earthquake sequence. In contrast, analysis of pore-pressure models shows that the combination of formation water production and wastewater injection near the fault could have caused pressure increases that induced earthquakes on near-critically stressed faults.

  9. Seismic source inversion using Green's reciprocity and a 3-D structural model for the Japanese Islands

    NASA Astrophysics Data System (ADS)

    Simutė, S.; Fichtner, A.

    2015-12-01

    We present a feasibility study for seismic source inversions using a 3-D velocity model for the Japanese Islands. The approach involves numerically calculating 3-D Green's tensors, which is made efficient by exploiting Green's reciprocity. The rationale for 3-D seismic source inversion has several aspects. For structurally complex regions, such as the Japan area, it is necessary to account for 3-D Earth heterogeneities to prevent unknown structure polluting source solutions. In addition, earthquake source characterisation can serve as a means to delineate existing faults. Source parameters obtained for more realistic Earth models can then facilitate improvements in seismic tomography and early warning systems, which are particularly important for seismically active areas, such as Japan. We have created a database of numerically computed 3-D Green's reciprocals for a 40°× 40°× 600 km size area around the Japanese Archipelago for >150 broadband stations. For this we used a regional 3-D velocity model, recently obtained from full waveform inversion. The model includes attenuation and radial anisotropy and explains seismic waveform data for periods between 10 - 80 s generally well. The aim is to perform source inversions using the database of 3-D Green's tensors. As preliminary steps, we present initial concepts to address issues that are at the basis of our approach. We first investigate to which extent Green's reciprocity works in a discrete domain. Considering substantial amounts of computed Green's tensors we address storage requirements and file formatting. We discuss the importance of the initial source model, as an intelligent choice can substantially reduce the search volume. Possibilities to perform a Bayesian inversion and ways to move to finite source inversion are also explored.

  10. A Geo-referenced 3D model of the Juan de Fuca Slab and associated seismicity

    USGS Publications Warehouse

    Blair, J.L.; McCrory, P.A.; Oppenheimer, D.H.; Waldhauser, F.

    2011-01-01

    We present a Geographic Information System (GIS) of a new 3-dimensional (3D) model of the subducted Juan de Fuca Plate beneath western North America and associated seismicity of the Cascadia subduction system. The geo-referenced 3D model was constructed from weighted control points that integrate depth information from hypocenter locations and regional seismic velocity studies. We used the 3D model to differentiate earthquakes that occur above the Juan de Fuca Plate surface from earthquakes that occur below the plate surface. This GIS project of the Cascadia subduction system supersedes the one previously published by McCrory and others (2006). Our new slab model updates the model with new constraints. The most significant updates to the model include: (1) weighted control points to incorporate spatial uncertainty, (2) an additional gridded slab surface based on the Generic Mapping Tools (GMT) Surface program which constructs surfaces based on splines in tension (see expanded description below), (3) double-differenced hypocenter locations in northern California to better constrain slab location there, and (4) revised slab shape based on new hypocenter profiles that incorporate routine depth uncertainties as well as data from new seismic-reflection and seismic-refraction studies. We also provide a 3D fly-through animation of the model for use as a visualization tool.

  11. Towards Automated Seismic Moment Tensor Inversion in Australia Using 3D Structural Model

    NASA Astrophysics Data System (ADS)

    Hingee, M.; Tkalcic, H.; Fichtner, A.; Sambridge, M.; Kennett, B. L.; Gorbatov, A.

    2009-12-01

    There is significant seismic activity in the region around Australia, largely due to the plate boundaries to the north and to the east of the mainland. This seismicity poses serious seismic and tsunamigenic hazard in a wider region, and risk to coastal areas of Australia, and is monitored by Geoscience Australia (GA) using a network of permanent broadband seismometers within Australia. Earthquake and tsunami warning systems were established by the Australian Government and have been using the waveforms from the GA seismological network. The permanent instruments are augmented by non-GA seismic stations based both within and outside of Australia. In particular, seismic moment tensor (MT) solutions for events around Australia as well as local distances are useful for both warning systems and geophysical studies in general. These monitoring systems, however, currently use only one dimensional, spherically-symmetric models of the Earth for source parameter determination. Recently, a novel 3D model of Australia and the surrounding area has been developed from spectral element simulations [1], taking into account not only velocity heterogeneities, but also radial anisotropy and seismic attenuation. This development, inter alia, introduces the potential of providing significant improvements in MT solution accuracy. Allowing reliable MT solutions with reduced dependence on non-GA stations is a secondary advantage. We studied the feasibility of using 1D versus 3D structural models. The accuracy of the 3D model has been investigated, confirming that these models are in most cases superior to the 1D models. A full MT inversion method using a point source approximation was developed as the first step, keeping in mind that for more complex source time functions, a finite source inversion will be needed. Synthetic experiments have been performed with random noise added to the signal to test the code in the both 1D and 3D setting, using a precomputed library of structural Greens

  12. 3-D seismic tomographic modelling of the crustal structure of northwestern Svalbard based on deep seismic soundings

    NASA Astrophysics Data System (ADS)

    Czuba, Wojciech

    2016-11-01

    Wide angle refraction and reflection measurements were carried out in the passive continental margin zone of the northwestern Svalbard during several expeditions in 1978-1999. Data from a set of 2-D archival and modern seismic profiles recorded in-line and off-line, and from an additional permanent seismic station, were altogether used for seismic modelling of the crustal structure of the study area. Seismic arrivals (airgun and chemical explosive sources) were recorded by land (onshore) seismic stations, ocean bottom seismometers (OBS), and ocean bottom hydrophone stations (OBH). Good quality refracted and reflected P waves have provided an excellent data base for a seismic modelling. Chemical explosive sources were recorded even up to 300 km distances. The 3-D tomographic inversion method was applied. The results are comparable to the earlier 2-D modelling. Additional off-line information allowed to develop a 3-D image of the crustal structure. The continental crust thins to the west and north. A minimum depth of about 6 km to the Moho interface was determined east of the Molloy Deep and in the Knipovich Ridge. The Moho discontinuity deepens down to about 30 km below the continental crust of Spitsbergen.

  13. 3-D seismic tomographic modelling of the crustal structure of northwestern Svalbard based on deep seismic soundings

    NASA Astrophysics Data System (ADS)

    Czuba, Wojciech

    2017-01-01

    Wide angle refraction and reflection measurements were carried out in the passive continental margin zone of the northwestern Svalbard during several expeditions in 1978-1999. Data from a set of 2-D archival and modern seismic profiles recorded in-line and off-line, and from an additional permanent seismic station, were altogether used for seismic modelling of the crustal structure of the study area. Seismic arrivals (airgun and chemical explosive sources) were recorded by land (onshore) seismic stations, ocean bottom seismometers (OBS), and ocean bottom hydrophone stations (OBH). Good quality refracted and reflected P waves have provided an excellent data base for a seismic modelling. Chemical explosive sources were recorded even up to 300 km distances. The 3-D tomographic inversion method was applied. The results are comparable to the earlier 2-D modelling. Additional off-line information allowed to develop a 3-D image of the crustal structure. The continental crust thins to the west and north. A minimum depth of about 6 km to the Moho interface was determined east of the Molloy Deep and in the Knipovich Ridge. The Moho discontinuity deepens down to about 30 km below the continental crust of Spitsbergen.

  14. Geological model of Lobodice underground gas storage facility based on 3D seismic interpretation

    NASA Astrophysics Data System (ADS)

    Kopal, Lukáš; Čížek, Pavel; Milička, Ján

    2016-06-01

    The Lobodice underground gas storage (UGS) is developed in a natural aquifer reservoir located in the Central Moravian part of the Carpathian Foredeep in the Czech Republic. In order to learn more about the UGS geological structure a 3D seismic survey was performed in 2009. The reservoir is rather shallow, 400-500 m below the surface. This article describes the process workflow from the 3D seismic field data acquisition to the creation of the geological model. The outcomes of this workflow define the geometry of the UGS reservoir, its tectonics and the sealing features of the structure. Better geological knowledge of the reservoir will reduce the risks involved in the localization of new wells for increasing UGS withdrawal rates.

  15. Multi-hole seismic modeling in 3-D space and cross-hole seismic tomography analysis for boulder detection

    NASA Astrophysics Data System (ADS)

    Cheng, Fei; Liu, Jiangping; Wang, Jing; Zong, Yuquan; Yu, Mingyu

    2016-11-01

    A boulder stone, a common geological feature in south China, is referred to the remnant of a granite body which has been unevenly weathered. Undetected boulders could adversely impact the schedule and safety of subway construction when using tunnel boring machine (TBM) method. Therefore, boulder detection has always been a key issue demanded to be solved before the construction. Nowadays, cross-hole seismic tomography is a high resolution technique capable of boulder detection, however, the method can only solve for velocity in a 2-D slice between two wells, and the size and central position of the boulder are generally difficult to be accurately obtained. In this paper, the authors conduct a multi-hole wave field simulation and characteristic analysis of a boulder model based on the 3-D elastic wave staggered-grid finite difference theory, and also a 2-D imaging analysis based on first arrival travel time. The results indicate that (1) full wave field records could be obtained from multi-hole seismic wave simulations. Simulation results describe that the seismic wave propagation pattern in cross-hole high-velocity spherical geological bodies is more detailed and can serve as a basis for the wave field analysis. (2) When a cross-hole seismic section cuts through the boulder, the proposed method provides satisfactory cross-hole tomography results; however, when the section is closely positioned to the boulder, such high-velocity object in the 3-D space would impact on the surrounding wave field. The received diffracted wave interferes with the primary wave and in consequence the picked first arrival travel time is not derived from the profile, which results in a false appearance of high-velocity geology features. Finally, the results of 2-D analysis in 3-D modeling space are comparatively analyzed with the physical model test vis-a-vis the effect of high velocity body on the seismic tomographic measurements.

  16. High-resolution 3D seismic model of the crustal and uppermost mantle structure in Poland

    NASA Astrophysics Data System (ADS)

    Grad, Marek; Polkowski, Marcin; Ostaficzuk, Stanisław R.

    2016-01-01

    In the area of Poland a contact between the Precambrian and Phanerozoic Europe and the Carpathians has a complicated structure and a complex P-wave velocity of the sedimentary cover, crystalline crust, Moho depth and the uppermost mantle. The geometry of the uppermost several kilometers of sediments is relatively well recognized from over 100,000 boreholes. The vertical seismic profiling (VSP) from 1188 boreholes provided detailed velocity data for regional tectonic units and for stratigraphic successions from Permian to the Tertiary and Quaternary deposits. These data, however, do not provide information about the velocity and basement depth in the central part of the Trans-European suture zone (TESZ) and in the Carpathians. So, the data set is supplemented by 2D velocity models from 32 deep seismic sounding refraction profiles which also provide information about the crust and uppermost mantle. Together with the results of other methods: vertical seismic profiling, magnetotelluric, allow for the creation of a detailed, high-resolution 3D model for the entire Earth's crust and the uppermost mantle down to a depth of 60 km. The thinnest sedimentary cover in the Mazury-Belarus anteclise is only 0.3 to 1 km thick, which increases to 7 to 8 km along the East European Craton (EEC) margin, and 9 to 12 km in the TESZ. The Variscan domain is characterized by a 1-4 km thick sedimentary cover, while the Carpathians are characterized by very thick sedimentary layers, up to about 20 km. The crystalline crust is differentiated and has a layered structure. The crust beneath the West European Platform (WEP; Variscan domain) is characterized by P-wave velocities of 5.8-6.6 km/s. The upper and middle crusts beneath the EEC are characterized by velocities of 6.1-6.6 km/s, and are underlain by a high velocity lower crust with a velocity of about 7 km/s. A general decrease in velocity is observed from the older to the younger tectonic domains. The TESZ is associated with a steep dip

  17. Validation of 3D Seismic Velocity Models Using the Spectral Element Method

    NASA Astrophysics Data System (ADS)

    Maceira, M.; Larmat, C. S.; Porritt, R. W.; Higdon, D.; Allen, R. M.

    2012-12-01

    For over a decade now, many research institutions have been focusing on addressing the Earth's 3D heterogeneities and complexities by improving tomographic methods. Utilizing dense array datasets, these efforts have led to unprecedented 3D seismic images, but little is done in terms of model validation or to provide any absolute assessment of model uncertainty. Furthermore, the question of "How good is a 3D geophysical model at representing the Earth's true physics? " remains largely not addressed in a time when 3D Earth models are used for societal and energy security. In the last few years, new horizons have opened up in earth structure imaging, with the advent of new numerical and mathematical methods in computational seismology and statistical sciences. We use these methods to tackle the question of model validation taking advantage of unique and extensive High Performance Computing resources available at Los Alamos National Laboratory. We present results from a study focused on validating 3D models for the Western USA generated using both ray-theoretical and finite-frequency approximations. In this manner we do not validate just the model but also the imaging technique. For this test case, we utilize the Dynamic North America (DNA) model family of UC Berkeley, as they are readily available in both formulations. We evaluate model performances by comparing observed and synthetic seismograms generated using the Spectral Element Method. Results show that both, finite-frequency and ray-theoretical DNA09 models, predict the observations well. Waveform cross-correlation coefficients show a difference in performance between models obtained with the finite-frequency or ray-theory limited to smallest periods (<15s), with no perceptible difference at longer periods (50-200s). At those shortest periods, and based on statistical analyses on S-wave phase delay measurements, finite-frequency shows an improvement over ray theory. We are also investigating the breakdown of ray

  18. Modeling the Coast Mountains Batholith, British Columbia, Canada with 3D Seismic Tomography

    NASA Astrophysics Data System (ADS)

    Quinonez, S. M.; Olaya, J. C.; Miller, K. C.; Romero, R.; Velasco, A. A.; Harder, S. H.; Cerda, I.

    2011-12-01

    The Coast Mountains Batholith on the west coast of British Columbia, Canada comprises a series of granitic to tonalitic plutons; where felsic continental crust is generated from the subduction of mafic oceanic crust by partial melting and fractionation, leaving ultra-mafic roots. In July of 2009, a large controlled-source experiment was conducted along a 400km east - west transect from Bella Bella into central British Columbia. Student volunteers from multiple universities deployed 1,800 one-component and 200 three-component geophones plus 2400 Texan data recorders with 200-m spacing intervals and shot spacing at 30-km. The 18-point sources ranged from 160 to 1,000 kg of high explosive. The geoscience component of the NSF-funded Cyber-ShARE project at UTEP focuses on fusing models developed from different data sets to develop 3-D Earth models. Created in 2007, the Cyber-ShARE Center brings together experts in computer science, computational mathematics, education, earth science, and environmental science. We leverage the Cyber-ShARE work to implement an enhanced 3-D finite difference tomography approach for P-wave delays times (Hole, 1992) with a graphical user interface and visualization framework. In particular, to account for model sensitivity to picked P-wave arrival times, we use a model fusion approach (Ochoa et al., 2010) to generate a model with the lowest RMS residual that a combination of a set of Monte Carlo sample models. In order to make the seismic tomography process more interactive at many points, visualizations of model perturbation at each iteration will help to troubleshoot when a model is not converging to highlight where the RMS residual values are the highest to pinpoint where changes need to be made to achieve model convergence. Finally, a model of the upper mantle using 3-D P-wave tomography will be made to determine the location of these ultra-mafic roots.

  19. Seismic shaking scenarios in realistic 3D crustal model of Northern Italy

    NASA Astrophysics Data System (ADS)

    Molinari, I.; Morelli, A.; Basini, P.; Berbellini, A.

    2013-12-01

    Simulation of seismic wave propagation in realistic crustal structures is a fundamental tool to evaluate earthquake-generated ground shaking and assess seismic hazard. Current-generation numerical codes, and modern HPC infrastructures, allow for realistic simulations in complex 3D geologic structures. We apply such methodology to the Po Plain in Northern Italy -- a region with relatively rare earthquakes but having large property and industrial exposure, as it became clear during the two M~6 events of May 20-29, 2012. Historical seismicity is well known in this region, with maximum magnitudes estimates reaching M~7, and wave field amplitudes may be significantly amplified by the presence of the very thick sedimentary basin. Our goal is to produce estimates of expected ground shaking in Northern Italy through detailed deterministic simulations of ground motion due to expected earthquakes. We defined a three-dimensional model of the earth's crust using geo-statistical tools to merge the abundant information existing in the form of borehole data and seismic reflection profiles that had been shot in the '70s and the '80s for hydrocarbon exploration. Such information, that has been used by geologists to infer the deep structural setup, had never been merged to build a 3D model to be used for seismological simulations. We implement the model in SPECFEM3D_Cartesian and a hexahedral mesh with elements of ~2km, that allows us to simulate waves with minimum period of ~2 seconds. The model has then been optimized through comparison between simulated and recorded seismograms for the ~20 moderate-magnitude events (Mw > 4.5) that have been instrumentally recorded in the last 15 years. Realistic simulations in the frequency band of most common engineering relevance -- say, ~1 Hz -- at such a large scale would require an extremely detailed structural model, currently not available, and prohibitive computational resources. However, an interest is growing in longer period ground

  20. Refining the 3D seismic velocity and attenuation models for Katmai National Park, Alaska

    NASA Astrophysics Data System (ADS)

    Murphy, R. A.; Thurber, C. H.; Prejean, S. G.

    2009-12-01

    We invert data from approximately 4,000 local earthquakes occurring between September 2004 and August 2009 to determine the 3D P-wave velocity and P-wave attenuation structures in the Katmai volcanic region. Arrival information and waveforms for the study come from the Alaska Volcano Observatory’s permanent network of 20 seismometers in the area, which are predominantly single-component, short period instruments. The absolute and relative arrival times are used in a double-difference seismic tomography inversion to solve for an improved velocity model for the main volcanic centers. We use the resulting 3D velocity model to relocate all catalog earthquakes in Katmai between January 1996 and August 2009. Inversions for the quality factor Q are completed using a spectral decay approach to determine source parameters, t*, and site response with a nonlinear inversion. Using the final 3D velocity model to define the ray paths, t* values are then inverted to determine frequency-independent Q models. The final models developed through these inversions reveal a low velocity and low Q zone from the surface to ~7 km depth centered on the volcanic axis and extending ~25 km between Martin and Katmai volcanoes. The relocated hypocenters provide insight into the geometry of seismogenic structures in the area, revealing clustering of events into four distinct zones associated with Martin, Mageik, Trident, and Katmai. While the Martin, Mageik, and Katmai clusters are all at 3-4 km depth, the Trident cluster is slightly deeper at 4-6 km. Many new features are apparent within these clusters, including a strand of earthquakes trending NE-SW between the main Martin and Mageik clusters. Smaller linear features are also visible in the Katmai cluster along with a small migrating swarm which occurred NW of the Katmai caldera during mid-2006. Data from an array of 11 three-component broadband instruments currently deployed in the area between Mageik volcano and Katmai caldera will be

  1. Vectorial seismic modeling for 3D objects by the classical solution

    NASA Astrophysics Data System (ADS)

    Ávila-Carrera, R.; Sánchez-Sesma, F. J.; Rodríguez-Castellanos, A.; Ortiz-Alemán, C.

    2010-09-01

    The analytic benchmark solution for the scattering and diffraction of elastic P- and S-waves by a single spherical obstacle is presented in a condensed format. Our aim is divulge to the scientific community this not widely known classical solution to construct a direct seismic model for 3D objects. Some of the benchmark papers are frequently plagued by misprints and none offers results on the transient response. The treatment of the vectorial case appears to be insipient in the literature. The classical solution is a superposition of incident and diffracted fields. Plane P- or S-waves are assumed. They are expressed as expansions of spherical wave functions which are tested against exact results. The diffracted field by the obstacle is calculated from the analytical enforcing of boundary conditions at the scatterer-matrix interface. The spherical obstacle is a cavity, an elastic inclusion or a fluid-filled body. A complete set of wave functions is used in terms of Bessel and Hankel radial functions. Legendre and trigonometric functions are used for the angular coordinates. In order to provide information to calibrate and approximate the seismic modeling for real objects, results are shown in time and frequency domains. Diffracted displacements amplitudes versus normalized frequency and radiation patterns for various scatterer-matrix properties are reported. To study propagation features that may be useful to geophysicists and engineers, synthetic seismograms for some relevant cases are computed.

  2. Seismic Activity Seen Through Evolution of the Hurst Exponent Model in 3D

    NASA Astrophysics Data System (ADS)

    Patiño Ortiz, J.; Carreño Aguilera, R.; Balankin, A. S.; Patiño Ortiz, M.; Tovar Rodriguez, J. C.; Acevedo Mosqueda, M. A.; Martinez Cruz, M. A.; Yu, Wen

    2016-10-01

    The dynamics seismic activity occurred in the Cocos Plate - Mexico is analyzed through the evolution of Hurst exponent and 3D fractal dimension, under the mathematical fractal structure based on seismic activity time series, taking into account the magnitude (M) as the main parameter to be estimated. The seismic activity time series and, annual intervals are considered first for finding the Hurst exponent of each year since 1988 (the year in which the database is consistent) until 2012, and then the following years are accumulated describing the cumulative Hurst exponent. The seismic activity description is based on Cocos Plate data information; during a period conform from 1 January 1988 to 31 December 2012. Analyses were performed following methods, mainly considering that the Hurst exponent analysis provides the ability to find the seismicity behavior time-space, described by parameters obtained under the fractal dimension and complex systems.

  3. 3D Discontinuous Galerkin elastic seismic wave modeling based upon a grid injection method

    NASA Astrophysics Data System (ADS)

    Monteiller, V.

    2015-12-01

    Full waveform inversion (FWI) is a seismic imaging method that estimates thesub-surface physical properties with a spatial resolution of the order of thewavelength. FWI is generally recast as the iterative optimization of anobjective function that measures the distance between modeled and recordeddata. In the framework of local descent methods, FWI requires to perform atleast two seismic modelings per source and per FWI iteration.Due to the resulting computational burden, applications of elastic FWI have been usuallyrestricted to 2D geometries. Despite the continuous growth of high-performancecomputing facilities, application of 3D elastic FWI to real-scale problemsremain computationally too expensive. To perform elastic seismic modeling with a reasonable amount of time, weconsider a reduced computational domain embedded in a larger background modelin which seismic sources are located. Our aim is to compute repeatedly thefull wavefield in the targeted domain after model alteration, once theincident wavefield has been computed once for all in the background model. Toachieve this goal, we use a grid injection method referred to as the Total-Field/Scattered-Field (TF/SF) technique in theelectromagnetic community. We implemented the Total-Field/Scattered-Field approach in theDiscontinuous Galerkin Finite Element method (DG-FEM) that is used to performmodeling in the local domain. We show how to interface the DG-FEM with any modeling engine (analytical solution, finite difference or finite elements methods) that is suitable for the background simulation. One advantage of the Total-Field/Scattered-Field approach is related to thefact that the scattered wavefield instead of the full wavefield enter thePMLs, hence making more efficient the absorption of the outgoing waves at theouter edges of the computational domain. The domain reduction in which theDG-FEM is applied allows us to use modest computational resources opening theway for high-resolution imaging by full

  4. Full Waveform 3D Synthetic Seismic Algorithm for 1D Layered Anelastic Models

    NASA Astrophysics Data System (ADS)

    Schwaiger, H. F.; Aldridge, D. F.; Haney, M. M.

    2007-12-01

    Numerical calculation of synthetic seismograms for 1D layered earth models remains a significant aspect of amplitude-offset investigations, surface wave studies, microseismic event location approaches, and reflection interpretation or inversion processes. Compared to 3D finite-difference algorithms, memory demand and execution time are greatly reduced, enabling rapid generation of seismic data within workstation or laptop computational environments. We have developed a frequency-wavenumber forward modeling algorithm adapted to realistic 1D geologic media, for the purpose of calculating seismograms accurately and efficiently. The earth model consists of N layers bounded by two halfspaces. Each layer/halfspace is a homogeneous and isotropic anelastic (attenuative and dispersive) solid, characterized by a rectangular relaxation spectrum of absorption mechanisms. Compressional and shear phase speeds and quality factors are specified at a particular reference frequency. Solution methodology involves 3D Fourier transforming the three coupled, second- order, integro-differential equations for particle displacements to the frequency-horizontal wavenumber domain. An analytic solution of the resulting ordinary differential system is obtained. Imposition of welded interface conditions (continuity of displacement and stress) at all interfaces, as well as radiation conditions in the two halfspaces, yields a system of 6(N+1) linear algebraic equations for the coefficients in the ODE solution. An optimized inverse 2D Fourier transform to the space domain gives the seismic wavefield on a horizontal plane. Finally, three-component seismograms are obtained by accumulating frequency spectra at designated receiver positions on this plane, followed by a 1D inverse FFT from angular frequency ω to time. Stress-free conditions may be applied at the top or bottom interfaces, and seismic waves are initiated by force or moment density sources. Examples reveal that including attenuation

  5. 3D Geotechnical Soil Model of Nice, France, Inferred from Seismic Noise Measurements, for Seismic Hazard Assessment.

    NASA Astrophysics Data System (ADS)

    Bertrand, E.; Duval, A.; Castan, M.; Vidal, S.

    2007-12-01

    In seismic risk studies, the assessment of lithologic site effect is based on an accurate knowledge of mechanical properties and geometry of superficial geological formations. Therefore, we built a 3D subsurface model in the city of Nice, southeastern France, using not only geological and geotechnical data but also geophysical inputs. We used especially ambient vibration recordings to supply the lack of borehole data over the city. Nice spreads over 72 km2 and roughly 20% of the city is built upon recent alluvium deposits. Other parts of the city lie on Jurassic and Cretaceous rocks to the east and thick Pliocene conglomerates to the west. Nearly 450 boreholes located mainly in the alluvial valleys were used. Because they are essentially linked to previous planned constructions (such as road network or important building), their distribution is rather heterogeneous over the studied area. In the valleys moreover, less than 40% of the boreholes are reaching the rock basement. These boreholes have been analyzed and a representative soil column made of 9 sedimentary layers has been recognized. Shear wave velocity of these layers were obtained from Standard Penetration Test values using several empirical correlation law described in the literature. Because of its cost, an extended boring survey was not feasible to complete our data set. Traditional seismic profiling was also not intended, as it is not possible to use intensive explosive sources in town. Recent years have seen many studies using ambient vibration measurements for site effect estimation. Especially, the very simple H/V technique was proven to be suitable for microzoning studies although some limitation were pointed out when dealing with 2D or 3D structures. Nevertheless, this technique alone provides only the fundamental eigenfrequency of the site under investigation. But assuming the shear wave velocity in the sediment it can helps to constrain the depth of the bedrock thanks to the well known f0=VS/4H

  6. A probabilistic approach to jointly integrate 3D/4D seismic, production data and geological information for building reservoir models

    NASA Astrophysics Data System (ADS)

    Castro, Scarlet A.

    Reservoir modeling aims at understanding static and dynamic components of the reservoir in order to make decisions about future surface operations. The practice of reservoir modeling calls for the integration of expertise from different disciplines, as well as the in tegration of a wide variety of data: geological data, (core data, well-logs, etc.), production data (fluid rates or volumes, pressure data, etc.), and geophysical data (3D seismic data). Although a single 3D seismic survey is the most common geophysical data available for most reservoirs, a suite of several 3D seismic surveys (4D seismic data) acquired for monitoring production can be available for mature reservoirs. The main contribution of this dissertation is to incorporate 4D seismic data within the reservoir modeling workflow while honoring all other available data. This dissertation proposes two general approaches to include 4D seismic data into the reservoir modeling workflow. The Probabilistic Data Integration approach (PDI), which consists of modeling the information content of 4D seismic through a spatial probability of facies occurrence; and the Forward Modeling (FM) approach, which consists of matching 4D seismic along with production data. The FM approach requires forward modeling the 4D seismic response, which requires to downscale the flow simulation response. This dissertation introduces a novel dynamic downscaling method that takes into account both static information (high-resolution per meability field) and dynamic information in the form of coarsened fluxes and saturations (flow simulation on the coarsened grid). The two proposed approaches (PDI and FM approaches) are applied to a prominent field in the North Sea, to model the channel facies of a fluvial reservoir. The PDI approach constrained the reservoir model to the spatial probability of facies occurrence (obtained from a calibration between well-log and 4D seismic data) as well as other static data while satisfactorily history

  7. Investigation of 3-D lateral variations on seismic waveform modeling, in preparation for the InSight mission to Mars

    NASA Astrophysics Data System (ADS)

    Drilleau, M.; Dubois, A.; Blanchette-Guertin, J. F.; Kawamura, T.; Lognonne, P. H.

    2015-12-01

    In 2016, the InSight mission will provide the very first seismic records from Mars after installing a seismometer on the surface of the Red Planet. Obtaining information on the deep 1-D seismic structure of Mars using a single geophysical station will be challenging. However, successful test inversions using body and surface waves have been presented in a preliminary study by Panning et al. (2015). Future investigations need now to focus on inversions making a complete use of the seismic waveform. An important challenge is to investigate the effects of 3-D lateral variations of seismic velocity structures on seismograms. The HOPT (Higher Order Perturbation Theory) code originally developed by P. Lognonné and E. Clévédé (Lognonné, 1991 ; Lognonné and Clévédé, 2002) and based on the perturbation theory allows for the computation of synthetic seismograms in a 3-D Earth. We adapted the code for Mars and computed surface wave synthetics in a 3-D planet, initially only considering the effects of the planet's ellipticity as well as the lateral variations in the depth of the Moho which are known through gravity measurements (e.g. Neumann et al., 2004). Additional constraints from lateral variations in topography will be the focus of future work. These synthetics can be compared to future seismic data in order to identify a suite of Martian internal structure models that best match the data. To do so, we first need to estimate the resolvable parameters concerning the Mars deep interior while considering the 3-D effects, which is the main goal of this study. Furthermore, in preparation for the InSight mission data return phase, the computation of these synthetic (but realistic) seismograms is primordial to test the softwares developed by the InSight Mars Quake and Mars Structure Services (in charge of locating the seismic events, and using them to assess the internal structure of Mars).

  8. Seismic moment tensor inversion using 3D velocity model and its application to the 2013 Lushan earthquake sequence

    NASA Astrophysics Data System (ADS)

    Zhu, Lupei; Zhou, Xiaofeng

    2016-10-01

    Source inversion of small-magnitude events such as aftershocks or mine collapses requires use of relatively high frequency seismic waveforms which are strongly affected by small-scale heterogeneities in the crust. In this study, we developed a new inversion method called gCAP3D for determining general moment tensor of a seismic source using Green's functions of 3D models. It inherits the advantageous features of the "Cut-and-Paste" (CAP) method to break a full seismogram into the Pnl and surface-wave segments and to allow time shift between observed and predicted waveforms. It uses grid search for 5 source parameters (relative strengths of the isotropic and compensated-linear-vector-dipole components and the strike, dip, and rake of the double-couple component) that minimize the waveform misfit. The scalar moment is estimated using the ratio of L2 norms of the data and synthetics. Focal depth can also be determined by repeating the inversion at different depths. We applied gCAP3D to the 2013 Ms 7.0 Lushan earthquake and its aftershocks using a 3D crustal-upper mantle velocity model derived from ambient noise tomography in the region. We first relocated the events using the double-difference method. We then used the finite-differences method and reciprocity principle to calculate Green's functions of the 3D model for 20 permanent broadband seismic stations within 200 km from the source region. We obtained moment tensors of the mainshock and 74 aftershocks ranging from Mw 5.2 to 3.4. The results show that the Lushan earthquake is a reverse faulting at a depth of 13-15 km on a plane dipping 40-47° to N46° W. Most of the aftershocks occurred off the main rupture plane and have similar focal mechanisms to the mainshock's, except in the proximity of the mainshock where the aftershocks' focal mechanisms display some variations.

  9. Crustal density structure in northwestern South America derived from analysis and 3-D modeling of gravity and seismicity data

    NASA Astrophysics Data System (ADS)

    Sanchez-Rojas, J.; Palma, M.

    2014-11-01

    This paper presents a three-dimensional (3-D) interpretation of new gravity and seismicity datasets for northern South America. A 3-D forward density model was constructed on the basis of deep wide-angle seismic refraction sections, Moho depth from receiver functions, and surface geology. Density values were estimated from published borehole data for sediments by using empirical velocity-density functions and considering mineralogical-chemical composition variations under typical pressure-temperature conditions for upper and lower crustal rocks. The modeled 3-D density structure was kept as simple as possible. The continental and oceanic plates were formed by two sedimentary bodies, one crustal body, and one mantle lithosphere body overlying a sub-lithospheric mantle. The Caribbean plate was modeled with an atypical crustal thickness of ~ 18 km (including sediments). The geometry of the Caribbean plate was modeled using a combination of gravity modeling and analyses of the seismicity and focal-mechanism solutions. Intermediate seismicity and the orientation of the T-axes appeared aligned along the predicted position of the slab. As a result, the estimated slab dip angle under Maracaibo and the Mérida Andes was ~ 15° and increases up to ~ 20° after 100 km depth. The model shows two orientations in the slab strike: ~ N150°E ± 5 in western Colombia and southward underneath the Maracaibo block. The modeling results suggest that the northern South American upper and lower crusts are relatively light and the density of the Caribbean crust is typical for an oceanic crust.

  10. Modeling and validation of a 3D velocity structure for the Santa Clara Valley, California, for seismic-wave simulations

    USGS Publications Warehouse

    Hartzell, S.; Harmsen, S.; Williams, R.A.; Carver, D.; Frankel, A.; Choy, G.; Liu, P.-C.; Jachens, R.C.; Brocher, T.M.; Wentworth, C.M.

    2006-01-01

    A 3D seismic velocity and attenuation model is developed for Santa Clara Valley, California, and its surrounding uplands to predict ground motions from scenario earthquakes. The model is developed using a variety of geologic and geophysical data. Our starting point is a 3D geologic model developed primarily from geologic mapping and gravity and magnetic surveys. An initial velocity model is constructed by using seismic velocities from boreholes, reflection/refraction lines, and spatial autocorrelation microtremor surveys. This model is further refined and the seismic attenuation is estimated through waveform modeling of weak motions from small local events and strong-ground motion from the 1989 Loma Prieta earthquake. Waveforms are calculated to an upper frequency of 1 Hz using a parallelized finite-difference code that utilizes two regions with a factor of 3 difference in grid spacing to reduce memory requirements. Cenozoic basins trap and strongly amplify ground motions. This effect is particularly strong in the Evergreen Basin on the northeastern side of the Santa Clara Valley, where the steeply dipping Silver Creek fault forms the southwestern boundary of the basin. In comparison, the Cupertino Basin on the southwestern side of the valley has a more moderate response, which is attributed to a greater age and velocity of the Cenozoic fill. Surface waves play a major role in the ground motion of sedimentary basins, and they are seen to strongly develop along the western margins of the Santa Clara Valley for our simulation of the Loma Prieta earthquake.

  11. 3-D geodynamic models of the India-Eurasia collision zone: Guiding numerical models with seismic and MT observations

    NASA Astrophysics Data System (ADS)

    Bischoff, S. H.; Flesch, L. M.

    2015-12-01

    Piecing together the uplift and growth of the Tibetan Plateau requires a robust understanding of the present-day dynamics of the India-Eurasia collision zone. To aid in the understanding of mountain building and plateau growth, we developed a 3D finite element model of the Tibetan Plateau following Flesch and Bendick (2012). Our model is based on the vast collection of published geophysical data and employs COMSOL Multiphysics (www.comsol.com). We assume model material properties from the wide variety of published seismic and MT studies, incorporated with an updated, vertically averaged, effective viscosity distribution from Flesch et al. (2001). We test potential relationships between conductance/seismic velocity and strength (viscosity) by modeling strength difference contacts at imaged interfaces. We quantify fitness of candidate 3D viscosity functions by comparing solved model surface velocities to observed surface velocities inferred from GPS and Quaternary fault slip rates. The model geometry incorporates Earth curvature and extends eastward from 65° to 110°E, northward from 15° to 45°N, and vertically down to 100 km below sea level. The physics of deformation is governed by the Stokes equations describing incompressible Newtonian fluid flow. Boundary conditions consist of free slip across the bottom surface (representing the lithosphere-asthenosphere boundary) and moving edge walls constrained by a GPS-derived, continuous velocity field. Model results indicate a tradeoff between crust and mantle dominant strength. Best-fit models are achieved by a combination of strong crust/upper mantle with additional strain accommodation in localized weak zones.

  12. 3-D Velocity Model of the Coachella Valley, Southern California Based on Explosive Shots from the Salton Seismic Imaging Project

    NASA Astrophysics Data System (ADS)

    Persaud, P.; Stock, J. M.; Fuis, G. S.; Hole, J. A.; Goldman, M.; Scheirer, D. S.

    2014-12-01

    We have analyzed explosive shot data from the 2011 Salton Seismic Imaging Project (SSIP) across a 2-D seismic array and 5 profiles in the Coachella Valley to produce a 3-D P-wave velocity model that will be used in calculations of strong ground shaking. Accurate maps of seismicity and active faults rely both on detailed geological field mapping and a suitable velocity model to accurately locate earthquakes. Adjoint tomography of an older version of the SCEC 3-D velocity model shows that crustal heterogeneities strongly influence seismic wave propagation from moderate earthquakes (Tape et al., 2010). These authors improve the crustal model and subsequently simulate the details of ground motion at periods of 2 s and longer for hundreds of ray paths. Even with improvements such as the above, the current SCEC velocity model for the Salton Trough does not provide a match of the timing or waveforms of the horizontal S-wave motions, which Wei et al. (2013) interpret as caused by inaccuracies in the shallow velocity structure. They effectively demonstrate that the inclusion of shallow basin structure improves the fit in both travel times and waveforms. Our velocity model benefits from the inclusion of known location and times of a subset of 126 shots detonated over a 3-week period during the SSIP. This results in an improved velocity model particularly in the shallow crust. In addition, one of the main challenges in developing 3-D velocity models is an uneven stations-source distribution. To better overcome this challenge, we also include the first arrival times of the SSIP shots at the more widely spaced Southern California Seismic Network (SCSN) in our inversion, since the layout of the SSIP is complementary to the SCSN. References: Tape, C., et al., 2010, Seismic tomography of the Southern California crust based on spectral-element and adjoint methods: Geophysical Journal International, v. 180, no. 1, p. 433-462. Wei, S., et al., 2013, Complementary slip distributions

  13. 3D density model of the upper mantle of Asia based on inversion of gravity and seismic tomography data

    NASA Astrophysics Data System (ADS)

    Kaban, Mikhail K.; Stolk, Ward; Tesauro, Magdala; El Khrepy, Sami; Al-Arifi, Nassir; Beekman, Fred; Cloetingh, Sierd A. P. L.

    2016-11-01

    We construct a new-generation 3D density model of the upper mantle of Asia and its surrounding areas based on a joint interpretation of several data sets. A recent model of the crust combining nearly all available seismic data is employed to calculate the impact of the crust on the gravity anomalies and observed topography and to estimate the residual mantle anomalies and residual topography. These fields are jointly inverted to calculate the density variations in the lithosphere and upper mantle down to 325 km. As an initial approximation, we estimate density variations using a seismic tomography model. Seismic velocity variations are converted into temperatures and then to density variations based on mineral physics constraints. In the Occam-type inversion, we fit both the residual mantle gravity anomalies and residual topography by finding deviations to the initial model. The obtained corrections improve the resolution of the initial model and reflect important features of the mantle structure that are not well resolved by the seismic tomography. The most significant negative corrections of the upper mantle density, found in the Siberian and East European cratons, can be associated with depleted mantle material. The most pronounced positive density anomalies are found beneath the Tarim and South Caspian basins, Barents Sea, and Bay of Bengal. We attribute these anomalies to eclogites in the uppermost mantle, which have substantially affected the evolution of the basins. Furthermore, the obtained results provide evidence for the presence of eclogites in the oceanic subducting mantle lithosphere.

  14. Using 3D Simulation of Elastic Wave Propagation in Laplace Domain for Electromagnetic-Seismic Inverse Modeling

    NASA Astrophysics Data System (ADS)

    Petrov, P.; Newman, G. A.

    2010-12-01

    -Fourier domain we had developed 3D code for full-wave field simulation in the elastic media which take into account nonlinearity introduced by free-surface effects. Our approach is based on the velocity-stress formulation. In the contrast to conventional formulation we defined the material properties such as density and Lame constants not at nodal points but within cells. This second order finite differences method formulated in the cell-based grid, generate numerical solutions compatible with analytical ones within the range errors determinate by dispersion analysis. Our simulator will be embedded in an inversion scheme for joint seismic- electromagnetic imaging. It also offers possibilities for preconditioning the seismic wave propagation problems in the frequency domain. References. Shin, C. & Cha, Y. (2009), Waveform inversion in the Laplace-Fourier domain, Geophys. J. Int. 177(3), 1067- 1079. Shin, C. & Cha, Y. H. (2008), Waveform inversion in the Laplace domain, Geophys. J. Int. 173(3), 922-931. Commer, M. & Newman, G. (2008), New advances in three-dimensional controlled-source electromagnetic inversion, Geophys. J. Int. 172(2), 513-535. Newman, G. A., Commer, M. & Carazzone, J. J. (2010), Imaging CSEM data in the presence of electrical anisotropy, Geophysics, in press.

  15. The application of seismic stratigraphic methods on exploration 3D seismic data to define a reservoir model in OPL 210, Deepwater Nigeria

    SciTech Connect

    Ragnhild, L.; Ventris, P.; Osahon, G.

    1995-08-01

    OPL 210 lies in deepwater on the northwestern flank of the Niger Delta. The partners in this block are Allied Energy and The Statoil and BP Alliance. The license has a 5 year initial exploration phase and carries a 2 well commitment. At present the database comprises a 1 x 1 km grid of 2D seismic across the block, and 450 sq. km of 3D in an area of special interest. A larger 3D survey is planned for 1995. Little is known about the reservoir in the deep water, but we expect our main target to be ponded slope and basin turbidites. As such the bulk of the shelf well data available has little or no relevance to the play type likely to be encountered. Prior to drilling, seismic stratigraphy has been one of several methods used to generate a consistent predictive reservoir model. The excellent quality and high resolution of the 3D data have allowed identification and detailed description of several distinctive seismic facies. These facies are described in terms of their internal geometries and stacking patterns. The geometries are then interpreted based on a knowledge of depositional processes from analog slope settings. This enables a predictive model to be constructed for the distribution of reservoir within the observed facies. These predictions will be tested by one of the first wells drilled in the Nigerian deepwater in mid 1995.

  16. Seismicity patterns along the Ecuadorian subduction zone: new constraints from earthquake location in a 3-D a priori velocity model

    NASA Astrophysics Data System (ADS)

    Font, Yvonne; Segovia, Monica; Vaca, Sandro; Theunissen, Thomas

    2013-04-01

    To improve earthquake location, we create a 3-D a priori P-wave velocity model (3-DVM) that approximates the large velocity variations of the Ecuadorian subduction system. The 3-DVM is constructed from the integration of geophysical and geological data that depend on the structural geometry and velocity properties of the crust and the upper mantle. In addition, specific station selection is carried out to compensate for the high station density on the Andean Chain. 3-D synthetic experiments are then designed to evaluate the network capacity to recover the event position using only P arrivals and the MAXI technique. Three synthetic earthquake location experiments are proposed: (1) noise-free and (2) noisy arrivals used in the 3-DVM, and (3) noise-free arrivals used in a 1-DVM. Synthetic results indicate that, under the best conditions (exact arrival data set and 3-DVM), the spatiotemporal configuration of the Ecuadorian network can accurately locate 70 per cent of events in the frontal part of the subduction zone (average azimuthal gap is 289° ± 44°). Noisy P arrivals (up to ± 0.3 s) can accurately located 50 per cent of earthquakes. Processing earthquake location within a 1-DVM almost never allows accurate hypocentre position for offshore earthquakes (15 per cent), which highlights the role of using a 3-DVM in subduction zone. For the application to real data, the seismicity distribution from the 3-D-MAXI catalogue is also compared to the determinations obtained in a 1-D-layered VM. In addition to good-quality location uncertainties, the clustering and the depth distribution confirm the 3-D-MAXI catalogue reliability. The pattern of the seismicity distribution (a 13 yr record during the inter-seismic period of the seismic cycle) is compared to the pattern of rupture zone and asperity of the Mw = 7.9 1942 and the Mw = 7.7 1958 events (the Mw = 8.8 1906 asperity patch is not defined). We observe that the nucleation of 1942, 1958 and 1906 events coincides with

  17. 3D Simulation of Elastic Wave Propagation in Heterogeneous Anisotropic Media in Laplace Domain for Electromagnetic-Seismic Inverse Modeling

    NASA Astrophysics Data System (ADS)

    Petrov, P.; Newman, G. A.

    2011-12-01

    Recent developments in high resolution imaging technology of subsurface objects involves a combination of different geophysical measurements (gravity, EM and seismic). A joint image of the subsurface geophysical attributes (velocity, electrical conductivity and density) requires the consistent treatment of the different geophysical data due to their differing physical nature. For example, in conducting media, which is typical of the Earth's interior, EM energy propagation is defined by a diffusive mechanism and may be characterized by two specific length scales: wavelength and skin depth. However, the propagation of seismic signals is a multiwave process and is characterized by a set of wavelengths. Thus, to consistently treat seismic and electromagnetic data an additional length scale is needed for seismic data that does not directly depend on a wavelength and describes a diffusive process, similar to EM wave propagation in the subsurface. Works by Brown et al.(2005), Shin and Cha(2008), and Shin and Ha(2008) suggest that an artificial damping of seismic wave fields via Laplace-Fourier transformation can be an effective approach to obtain a seismic data that have similar spatial resolution to EM data. The key benefit of such transformation is that diffusive wave-field inversion works well for both data sets: seismic (Brown et al.,2005; Shin and Cha,2008) and electromagnetic (Commer and Newman,2008; Newman et al.,2010). With the recent interest in the Laplace-Fourier domain full waveform inversion, 3D fourth and second-order finite-difference schemes for modeling of seismic wave propagation have been developed (Petrov and Newman, 2010). Incorporation of attenuation and anisotropy into a velocity model is a necessary step for a more realistic description of subsurface media. Here we consider the extension of our method which includes attenuation and VTI anisotropy. Our approach is based on the integro-interpolation technique for velocity-stress formulation. Seven

  18. 3-D seismic data for geohazards assessment

    SciTech Connect

    Gafford, W.T.

    1996-10-01

    Three-dimensional (3-D) seismic data, acquired for oil and gas exploration purposes, is now being used to supplement, or in some cases, even replace conventional high resolution geohazard surveys in the Gulf of Mexico. The use of 3-D seismic data has improved the identification and understanding of some types of geohazards and has resulted in a more thorough interpretation of the shallow geologic section. The use of seismic interpretation workstations has allowed the geohazard interpreter to apply new tools in geohazard analysis. Some of the newer geohazard analysis. Some of the newer geophysical technologies used for exploration purposes are now being adapted for use in the identification and assessment of drilling hazards in the near-seafloor sedimentary section.

  19. Calculating the Probability of Strong Ground Motions Using 3D Seismic Waveform Modeling - SCEC CyberShake

    NASA Astrophysics Data System (ADS)

    Gupta, N.; Callaghan, S.; Graves, R.; Mehta, G.; Zhao, L.; Deelman, E.; Jordan, T. H.; Kesselman, C.; Okaya, D.; Cui, Y.; Field, E.; Gupta, V.; Vahi, K.; Maechling, P. J.

    2006-12-01

    Researchers from the SCEC Community Modeling Environment (SCEC/CME) project are utilizing the CyberShake computational platform and a distributed high performance computing environment that includes USC High Performance Computer Center and the NSF TeraGrid facilities to calculate physics-based probabilistic seismic hazard curves for several sites in the Southern California area. Traditionally, probabilistic seismic hazard analysis (PSHA) is conducted using intensity measure relationships based on empirical attenuation relationships. However, a more physics-based approach using waveform modeling could lead to significant improvements in seismic hazard analysis. Members of the SCEC/CME Project have integrated leading-edge PSHA software tools, SCEC-developed geophysical models, validated anelastic wave modeling software, and state-of-the-art computational technologies on the TeraGrid to calculate probabilistic seismic hazard curves using 3D waveform-based modeling. The CyberShake calculations for a single probablistic seismic hazard curve require tens of thousands of CPU hours and multiple terabytes of disk storage. The CyberShake workflows are run on high performance computing systems including multiple TeraGrid sites (currently SDSC and NCSA), and the USC Center for High Performance Computing and Communications. To manage the extensive job scheduling and data requirements, CyberShake utilizes a grid-based scientific workflow system based on the Virtual Data System (VDS), the Pegasus meta-scheduler system, and the Globus toolkit. Probabilistic seismic hazard curves for spectral acceleration at 3.0 seconds have been produced for eleven sites in the Southern California region, including rock and basin sites. At low ground motion levels, there is little difference between the CyberShake and attenuation relationship curves. At higher ground motion (lower probability) levels, the curves are similar for some sites (downtown LA, I-5/SR-14 interchange) but different for

  20. 3D crustal seismic velocity model for the Gulf of Cadiz and adjacent areas (SW Iberia margin) based on seismic reflection and refraction profiles

    NASA Astrophysics Data System (ADS)

    Lozano, Lucía; Cantavella, Juan Vicente; Barco, Jaime; Carranza, Marta; Burforn, Elisa

    2016-04-01

    The Atlantic margin of the SW Iberian Peninsula and northern Morocco has been subject of study during the last 30 years. Many seismic reflection and refraction profiles have been carried out offshore, providing detailed information about the crustal structure of the main seafloor tectonic domains in the region, from the South Portuguese Zone and the Gulf of Cadiz to the Abyssal Plains and the Josephine Seamount. The interest to obtain a detailed and realistic velocity model for this area, integrating the available data from these studies, is clear, mainly to improve real-time earthquake hypocentral location and for tsunami and earthquake early warning. Since currently real-time seismic location tools allow the implementation of 3D velocity models, we aim to generate a full 3D crustal model. For this purpose we have reviewed more than 50 profiles obtained in different seismic surveys, from 1980 to 2008. Data from the most relevant and reliable 2D seismic velocity published profiles were retrieved. We first generated a Moho depth map of the studied area (latitude 32°N - 41°N and longitude 15°W - 5°W) by extracting Moho depths along each digitized profile with a 10 km spacing, and then interpolating this dataset using ordinary kriging method and generating the contour isodepth map. Then, a 3D crustal velocity model has been obtained. Selected vertical sections at different distances along each profile were considered to retrieve P-wave velocity values at each interface in order to reproduce the geometry and the velocity gradient within each layer. A double linear interpolation, both in distance and depth, with sampling rates of 10 km and 1 km respectively, was carried out to generate a (latitude, longitude, depth, velocity) matrix. This database of all the profiles was interpolated to obtain the P-wave velocity distribution map every kilometer of depth. The new 3D velocity model has been integrated in NonLinLoc location program to relocate several representative

  1. 3-D seismic imaging of complex geologies

    SciTech Connect

    Womble, D.E.; Dosanjh, S.S.; VanDyke, J.P.; Oldfield, R.A.; Greenberg, D.S.

    1995-02-01

    We present three codes for the Intel Paragon that address the problem of three-dimensional seismic imaging of complex geologies. The first code models acoustic wave propagation and can be used to generate data sets to calibrate and validate seismic imaging codes. This code reported the fastest timings for acoustic wave propagation codes at a recent SEG (Society of Exploration Geophysicists) meeting. The second code implements a Kirchhoff method for pre-stack depth migration. Development of this code is almost complete, and preliminary results are presented. The third code implements a wave equation approach to seismic migration and is a Paragon implementation of a code from the ARCO Seismic Benchmark Suite.

  2. 3D seismic image processing for interpretation

    NASA Astrophysics Data System (ADS)

    Wu, Xinming

    Extracting fault, unconformity, and horizon surfaces from a seismic image is useful for interpretation of geologic structures and stratigraphic features. Although interpretation of these surfaces has been automated to some extent by others, significant manual effort is still required for extracting each type of these geologic surfaces. I propose methods to automatically extract all the fault, unconformity, and horizon surfaces from a 3D seismic image. To a large degree, these methods just involve image processing or array processing which is achieved by efficiently solving partial differential equations. For fault interpretation, I propose a linked data structure, which is simpler than triangle or quad meshes, to represent a fault surface. In this simple data structure, each sample of a fault corresponds to exactly one image sample. Using this linked data structure, I extract complete and intersecting fault surfaces without holes from 3D seismic images. I use the same structure in subsequent processing to estimate fault slip vectors. I further propose two methods, using precomputed fault surfaces and slips, to undo faulting in seismic images by simultaneously moving fault blocks and faults themselves. For unconformity interpretation, I first propose a new method to compute a unconformity likelihood image that highlights both the termination areas and the corresponding parallel unconformities and correlative conformities. I then extract unconformity surfaces from the likelihood image and use these surfaces as constraints to more accurately estimate seismic normal vectors that are discontinuous near the unconformities. Finally, I use the estimated normal vectors and use the unconformities as constraints to compute a flattened image, in which seismic reflectors are all flat and vertical gaps correspond to the unconformities. Horizon extraction is straightforward after computing a map of image flattening; we can first extract horizontal slices in the flattened space

  3. Walker Ranch 3D seismic images

    SciTech Connect

    Robert J. Mellors

    2016-03-01

    Amplitude images (both vertical and depth slices) extracted from 3D seismic reflection survey over area of Walker Ranch area (adjacent to Raft River). Crossline spacing of 660 feet and inline of 165 feet using a Vibroseis source. Processing included depth migration. Micro-earthquake hypocenters on images. Stratigraphic information and nearby well tracks added to images. Images are embedded in a Microsoft Word document with additional information. Exact location and depth restricted for proprietary reasons. Data collection and processing funded by Agua Caliente. Original data remains property of Agua Caliente.

  4. Selectivity of seismic electric signal (SES) of the 2000 Izu earthquake swarm: a 3D FEM numerical simulation model.

    PubMed

    Huang, Qinghua; Lin, Yufeng

    2010-01-01

    Although seismic electric signal (SES) has been used for short-term prediction of earthquakes, selectivity of SES still remains as one of the mysterious features. As a case study, we made a numerical simulation based on a 3D finite element method (FEM) on the selectivity of SES observed in the case of the 2000 Izu earthquake swarm. Our numerical results indicated that the existence of conductive channel under Niijima island could explain the reported SES selectivity.

  5. Hypocenter relocation using a fast grid search method and a 3-D seismic velocity model for the Sumatra region

    SciTech Connect

    Nugroho, Hendro; Widiyantoro, Sri; Nugraha, Andri Dian

    2013-09-09

    Determination of earthquake hypocenter in Indonesia conducted by the Meteorological, Climatological, and Geophysical Agency (MCGA) has still used a 1-D seismic velocity model. In this research, we have applied a Fast Grid Search (FGM) method and a 3-D velocity model resulting from tomographic imaging to relocate earthquakes in the Sumatran region. The data were taken from the MCGA data catalog from 2009 to 2011 comprising of subduction zone and on land fault earthquakes with magnitude greater than 4 Mw. Our preliminary results show some significant changes in the depths of the relocated earthquakes which are in general deeper than the depths of hypocenters from the MCGA data catalog. The residual times resulting from the relocation process are smaller than those prior to the relocation. Encouraged by these results, we will continue to conduct hypocenter relocation for all events from the MCGA data catalog periodically in order to produce a new data catalog with good quality. We hope that the new data catalog will be useful for further studies.

  6. A comparative study between a rectilinear 3-D seismic survey and a concentric-circle 3-D seismic survey

    SciTech Connect

    Maldonado, B.; Hussein, H.S.

    1994-12-31

    Due to the rectilinear nature of the previous 3D seismic survey, the details necessary for proper interpretation were absent. Theoretically, concentric 3D seismic technology may provide an avenue for gaining more and higher quality data coverage. Problems associated with recording a rectilinear 3D seismic grid over the salt dome in this area have created the need to investigate the use of such procedures as the concentric-circle 3D seismic acquisition technique. The difficulty of imaging salt dome flanks with conventional rectilinear 3D seismic may be a result of the inability to precisely predict the lateral velocity-field variation adjacent to both salt and sediments. The dramatic difference in the interval velocities of salt and sediments causes the returning ray to severely deviate from being a hyperbolic path. This hampers the ability to predict imaging points near the salt/sediment interface. Perhaps the most difficult areas to image with rectilinear seismic surveys are underneath salt overhangs. Modeling suggests that a significant increase in the number of rays captured from beneath a salt overhang can be achieved with the concentric-circle method. This paper demonstrates the use of the ``circle shoot`` on a survey conducted over a salt dome in the Gulf of Mexico. A total of 80 concentric circles cover an area which is equivalent to 31,000 acres. The final post-stack data were sorted into bins with dimensions of 25 meters by 25 meters. A comparison of 3D rectilinear shooting vs. 3D concentric circle shooting over the same area will show an improvement in data quality and signal-to-noise characteristics.

  7. 3D geological to geophysical modelling and seismic wave propagation simulation: a case study from the Lalor Lake VMS (Volcanogenic Massive Sulphides) mining camp

    NASA Astrophysics Data System (ADS)

    Miah, Khalid; Bellefleur, Gilles

    2014-05-01

    The global demand for base metals, uranium and precious metals has been pushing mineral explorations at greater depth. Seismic techniques and surveys have become essential in finding and extracting mineral rich ore bodies, especially for deep VMS mining camps. Geophysical parameters collected from borehole logs and laboratory measurements of core samples provide preliminary information about the nature and type of subsurface lithologic units. Alteration halos formed during the hydrothermal alteration process contain ore bodies, which are of primary interests among geologists and mining industries. It is known that the alteration halos are easier to detect than the ore bodies itself. Many 3D geological models are merely projection of 2D surface geology based on outcrop inspections and geochemical analysis of a small number of core samples collected from the area. Since a large scale 3D multicomponent seismic survey can be prohibitively expensive, performance analysis of such geological models can be helpful in reducing exploration costs. In this abstract, we discussed challenges and constraints encountered in geophysical modelling of ore bodies and surrounding geologic structures from the available coarse 3D geological models of the Lalor Lake mining camp, located in northern Manitoba, Canada. Ore bodies in the Lalor lake VMS camp are rich in gold, zinc, lead and copper, and have an approximate weight of 27 Mt. For better understanding of physical parameters of these known ore bodies and potentially unknown ones at greater depth, we constructed a fine resolution 3D seismic model with dimensions: 2000 m (width), 2000 m (height), and 1500 m (vertical depth). Seismic properties (P-wave, S-wave velocities, and density) were assigned based on a previous rock properties study of the same mining camp. 3D finite-difference elastic wave propagation simulation was performed in the model using appropriate parameters. The generated synthetic 3D seismic data was then compared to

  8. Potential Geophysical Field Transformations and Combined 3D Modelling for Estimation the Seismic Site Effects on Example of Israel

    NASA Astrophysics Data System (ADS)

    Eppelbaum, Lev; Meirova, Tatiana

    2015-04-01

    It is well-known that the local seismic site effects may have a significant contribution to the intensity of damage and destruction (e.g., Hough et al., 1990; Regnier et al., 2000; Bonnefoy-Claudet et al., 2006; Haase et al., 2010). The thicknesses of sediments, which play a large role in amplification, usually are derived from seismic velocities. At the same time, thickness of sediments may be determined (or defined) on the basis of 3D combined gravity-magnetic modeling joined with available geological materials, seismic data and borehole section examination. Final result of such investigation is a 3D physical-geological model (PGM) reflecting main geological peculiarities of the area under study. Such a combined study needs in application of a reliable 3D mathematical algorithm of computation together with advanced methodology of 3D modeling. For this analysis the developed GSFC software was selected. The GSFC (Geological Space Field Calculation) program was developed for solving a direct 3-D gravity and magnetic prospecting problem under complex geological conditions (Khesin et al., 1996; Eppelbaum and Khesin, 2004). This program has been designed for computing the field of Δg (Bouguer, free-air or observed value anomalies), ΔZ, ΔX, ΔY , ΔT , as well as second derivatives of the gravitational potential under conditions of rugged relief and inclined magnetization. The geological space can be approximated by (1) three-dimensional, (2) semi-infinite bodies and (3) those infinite along the strike closed, L.H. non-closed, R.H. on-closed and open). Geological bodies are approximated by horizontal polygonal prisms. The program has the following main advantages (besides abovementioned ones): (1) Simultaneous computing of gravity and magnetic fields; (2) Description of the terrain relief by irregularly placed characteristic points; (3) Computation of the effect of the earth-air boundary by the method of selection directly in the process of interpretation; (4

  9. Frozen Gaussian approximation for 3-D seismic wave propagation

    NASA Astrophysics Data System (ADS)

    Chai, Lihui; Tong, Ping; Yang, Xu

    2017-01-01

    We present a systematic introduction on applying frozen Gaussian approximation (FGA) to compute synthetic seismograms in 3-D earth models. In this method, seismic wavefield is decomposed into frozen (fixed-width) Gaussian functions, which propagate along ray paths. Rather than the coherent state solution to the wave equation, this method is rigorously derived by asymptotic expansion on phase plane, with analysis of its accuracy determined by the ratio of short wavelength over large domain size. Similar to other ray-based beam methods (e.g. Gaussian beam methods), one can use relatively small number of Gaussians to get accurate approximations of high-frequency wavefield. The algorithm is embarrassingly parallel, which can drastically speed up the computation with a multicore-processor computer station. We illustrate the accuracy and efficiency of the method by comparing it to the spectral element method for a 3-D seismic wave propagation in homogeneous media, where one has the analytical solution as a benchmark. As another proof of methodology, simulations of high-frequency seismic wave propagation in heterogeneous media are performed for 3-D waveguide model and smoothed Marmousi model, respectively. The second contribution of this paper is that, we incorporate the Snell's law into the FGA formulation, and asymptotically derive reflection, transmission and free surface conditions for FGA to compute high-frequency seismic wave propagation in high contrast media. We numerically test these conditions by computing traveltime kernels of different phases in the 3-D crust-over-mantle model.

  10. 3-D frequency-domain seismic wave modelling in heterogeneous, anisotropic media using a Gaussian Quadrature Grid (GQG) approach

    NASA Astrophysics Data System (ADS)

    Greenhalgh, Stewart; Zhou, Bing; Maurer, Hansruedi

    2010-05-01

    We have developed a modified version of the spectral element method (SEM), called the Gaussian Quadrature Grid (GQG) approach, for frequency domain 3D seismic modelling in arbitrary heterogeneous, anisotropic media. The model may incorporate an arbitrary free-surface topography and irregular subsurface interfaces. Unlike the SEM ,it does not require a powerful mesh generator such as the Delauney Triangular or TetGen. Rather, the GQG approach replaces the element mesh with Gaussian quadrature abscissae to directly sample the physical properties of the model parameters and compute the weighted residual or variational integral. This renders the model discretisation simple and easily matched to the model topography, as well as direct control of the model paramterisation for subsequent inversion. In addition, it offers high accuracy in numerical modelling provided that an appropriate density of the Gaussian quadrature abscissae is employed. The second innovation of the GQG is the incorporation of a new implementation of perfectly matched layers to suppress artificial reflections from the domain margins. We employ PML model parameters (specified complex valued density and elastic moduli) rather than explicitly solving the governing wave equation with a complex co-ordinate system as in conventional approaches. Such an implementation is simple, general, effective and easily extendable to any class of anisotropy and other numerical modelling methods. The accuracy of the GQG approach is controlled by the number of Gaussian quadrature points per minimum wavelength, the so-called sampling density. The optimal sampling density should be the one which enables high definition of geological characteristics and high precision of the variational integral evaluation and spatial differentiation. Our experiments show that satisfactory results can be obtained using sampling densities of 5 points per minimum wavelength. Efficiency of the GQG approach mainly depends on the linear

  11. Imaging fault zones using 3D seismic image processing techniques

    NASA Astrophysics Data System (ADS)

    Iacopini, David; Butler, Rob; Purves, Steve

    2013-04-01

    Significant advances in structural analysis of deep water structure, salt tectonic and extensional rift basin come from the descriptions of fault system geometries imaged in 3D seismic data. However, even where seismic data are excellent, in most cases the trajectory of thrust faults is highly conjectural and still significant uncertainty exists as to the patterns of deformation that develop between the main faults segments, and even of the fault architectures themselves. Moreover structural interpretations that conventionally define faults by breaks and apparent offsets of seismic reflectors are commonly conditioned by a narrow range of theoretical models of fault behavior. For example, almost all interpretations of thrust geometries on seismic data rely on theoretical "end-member" behaviors where concepts as strain localization or multilayer mechanics are simply avoided. Yet analogue outcrop studies confirm that such descriptions are commonly unsatisfactory and incomplete. In order to fill these gaps and improve the 3D visualization of deformation in the subsurface, seismic attribute methods are developed here in conjunction with conventional mapping of reflector amplitudes (Marfurt & Chopra, 2007)). These signal processing techniques recently developed and applied especially by the oil industry use variations in the amplitude and phase of the seismic wavelet. These seismic attributes improve the signal interpretation and are calculated and applied to the entire 3D seismic dataset. In this contribution we will show 3D seismic examples of fault structures from gravity-driven deep-water thrust structures and extensional basin systems to indicate how 3D seismic image processing methods can not only build better the geometrical interpretations of the faults but also begin to map both strain and damage through amplitude/phase properties of the seismic signal. This is done by quantifying and delineating the short-range anomalies on the intensity of reflector amplitudes

  12. Improving Geologic and Engineering Models of Midcontinent Fracture and Karst-Modified Reservoirs Using New 3-D Seismic Attributes

    SciTech Connect

    Susan Nissen; Saibal Bhattacharya; W. Lynn Watney; John Doveton

    2009-03-31

    Our project goal was to develop innovative seismic-based workflows for the incremental recovery of oil from karst-modified reservoirs within the onshore continental United States. Specific project objectives were: (1) to calibrate new multi-trace seismic attributes (volumetric curvature, in particular) for improved imaging of karst-modified reservoirs, (2) to develop attribute-based, cost-effective workflows to better characterize karst-modified carbonate reservoirs and fracture systems, and (3) to improve accuracy and predictiveness of resulting geomodels and reservoir simulations. In order to develop our workflows and validate our techniques, we conducted integrated studies of five karst-modified reservoirs in west Texas, Colorado, and Kansas. Our studies show that 3-D seismic volumetric curvature attributes have the ability to re-veal previously unknown features or provide enhanced visibility of karst and fracture features compared with other seismic analysis methods. Using these attributes, we recognize collapse features, solution-enlarged fractures, and geomorphologies that appear to be related to mature, cockpit landscapes. In four of our reservoir studies, volumetric curvature attributes appear to delineate reservoir compartment boundaries that impact production. The presence of these compartment boundaries was corroborated by reservoir simulations in two of the study areas. Based on our study results, we conclude that volumetric curvature attributes are valuable tools for mapping compartment boundaries in fracture- and karst-modified reservoirs, and we propose a best practices workflow for incorporating these attributes into reservoir characterization. When properly calibrated with geological and production data, these attributes can be used to predict the locations and sizes of undrained reservoir compartments. Technology transfer of our project work has been accomplished through presentations at professional society meetings, peer-reviewed publications

  13. Earthquake relocation using a 3D a-priori geological velocity model from the western Alps to Corsica: Implication for seismic hazard

    NASA Astrophysics Data System (ADS)

    Béthoux, Nicole; Theunissen, Thomas; Beslier, Marie-Odile; Font, Yvonne; Thouvenot, François; Dessa, Jean-Xavier; Simon, Soazig; Courrioux, Gabriel; Guillen, Antonio

    2016-02-01

    The region between the inner zones of the Alps and Corsica juxtaposes an overthickened crust to an oceanic domain, which makes difficult to ascertain the focal depth of seismic events using routine location codes and average 1D velocity models. The aim of this article is to show that, even with a rather lose monitoring network, accurate routine locations can be achieved by using realistic 3D modelling and advanced location techniques. Previous earthquake tomography studies cover the whole region with spatial resolutions of several tens of kilometres on land, but they fail to resolve the marine domain due to the absence of station coverage and sparse seismicity. To overcome these limitations, we first construct a 3D a-priori P and S velocity model integrating known geophysical and geological information. Significant progress has been achieved in the 3D numerical modelling of complex geological structures by the development of dedicated softwares (e.g. 3D GeoModeller), capable at once of elaborating a 3D structural model from geological and geophysical constraints and, possibly, of refining it by inversion processes (Calcagno et al., 2008). Then, we build an arrival-time catalogue of 1500 events recorded from 2000 to 2011. Hypocentres are then located in this model using a numerical code based on the maximum intersection method (Font et al., 2004), updated by Theunissen et al. (2012), as well as another 3D location technique, the NonLinLoc software (Lomax and Curtis, 2001). The reduction of arrival-time residuals and uncertainties (dh, dz) with respect to classical 1D locations demonstrates the improved accuracy allowed by our approach and confirms the coherence of the 3D geological model built and used in this study. Our results are also compared with previous works that benefitted from the installation of dense temporary networks surrounding the studied epicentre area. The resulting 3D location catalogue allows us to improve the regional seismic hazard assessment

  14. Advanced computational tools for 3-D seismic analysis

    SciTech Connect

    Barhen, J.; Glover, C.W.; Protopopescu, V.A.

    1996-06-01

    The global objective of this effort is to develop advanced computational tools for 3-D seismic analysis, and test the products using a model dataset developed under the joint aegis of the United States` Society of Exploration Geophysicists (SEG) and the European Association of Exploration Geophysicists (EAEG). The goal is to enhance the value to the oil industry of the SEG/EAEG modeling project, carried out with US Department of Energy (DOE) funding in FY` 93-95. The primary objective of the ORNL Center for Engineering Systems Advanced Research (CESAR) is to spearhead the computational innovations techniques that would enable a revolutionary advance in 3-D seismic analysis. The CESAR effort is carried out in collaboration with world-class domain experts from leading universities, and in close coordination with other national laboratories and oil industry partners.

  15. 3D seismic imaging on massively parallel computers

    SciTech Connect

    Womble, D.E.; Ober, C.C.; Oldfield, R.

    1997-02-01

    The ability to image complex geologies such as salt domes in the Gulf of Mexico and thrusts in mountainous regions is a key to reducing the risk and cost associated with oil and gas exploration. Imaging these structures, however, is computationally expensive. Datasets can be terabytes in size, and the processing time required for the multiple iterations needed to produce a velocity model can take months, even with the massively parallel computers available today. Some algorithms, such as 3D, finite-difference, prestack, depth migration remain beyond the capacity of production seismic processing. Massively parallel processors (MPPs) and algorithms research are the tools that will enable this project to provide new seismic processing capabilities to the oil and gas industry. The goals of this work are to (1) develop finite-difference algorithms for 3D, prestack, depth migration; (2) develop efficient computational approaches for seismic imaging and for processing terabyte datasets on massively parallel computers; and (3) develop a modular, portable, seismic imaging code.

  16. 3D modelling of the active normal fault network in the Apulian Ridge (Eastern Mediterranean Sea): Integration of seismic and bathymetric data with implicit surface methods

    NASA Astrophysics Data System (ADS)

    Bistacchi, Andrea; Pellegrini, Caludio; Savini, Alessandra; Marchese, Fabio

    2016-04-01

    The Apulian ridge (North-eastern Ionian Sea, Mediterranean), interposed between the facing Apennines and Hellenides subduction zones (to the west and east respectively), is characterized by thick cretaceous carbonatic sequences and discontinuous tertiary deposits crosscut by a penetrative network of NNW-SSE normal faults. These are exposed onshore in Puglia, and are well represented offshore in a dataset composed of 2D seismics and wells collected by oil companies from the '60s to the '80s, more recent seismics collected during research projects in the '90s, recent very high resolution seismics (VHRS - Sparker and Chirp-sonar data), multibeam echosounder bathymetry, and sedimentological and geo-chronological analyses of sediment samples collected on the seabed. Faults are evident in 2D seismics at all scales, and their along-strike geometry and continuity can be characterized with multibeam bathymetric data, which show continuous fault scarps on the seabed (only partly reworked by currents and covered by landslides). Fault scarps also reveal the finite displacement accumulated in the Holocene-Pleistocene. We reconstructed a 3D model of the fault network and suitable geological boundaries (mainly unconformities due to the discontinuous distribution of quaternary and tertiary sediments) with implicit surface methods implemented in SKUA/GOCAD. This approach can be considered very effective and allowed reconstructing in details complex structures, like the frequent relay zones that are particularly well imaged by seafloor geomorphology. Mutual cross-cutting relationships have been recognized between fault scarps and submarine mass-wasting deposits (Holocene-Pleistocene), indicating that, at least in places, these features are coeval, hence the fault network should be considered active. At the regional scale, the 3D model allowed measuring the horizontal WSW-ENE stretching, which can be associated to the bending moment applied to the Apulian Plate by the combined effect

  17. 3D Reservoir Modeling of Semutang Gas Field: A lonely Gas field in Chittagong-Tripura Fold Belt, with Integrated Well Log, 2D Seismic Reflectivity and Attributes.

    NASA Astrophysics Data System (ADS)

    Salehin, Z.; Woobaidullah, A. S. M.; Snigdha, S. S.

    2015-12-01

    Bengal Basin with its prolific gas rich province provides needed energy to Bangladesh. Present energy situation demands more Hydrocarbon explorations. Only 'Semutang' is discovered in the high amplitude structures, where rest of are in the gentle to moderate structures of western part of Chittagong-Tripura Fold Belt. But it has some major thrust faults which have strongly breached the reservoir zone. The major objectives of this research are interpretation of gas horizons and faults, then to perform velocity model, structural and property modeling to obtain reservoir properties. It is needed to properly identify the faults and reservoir heterogeneities. 3D modeling is widely used to reveal the subsurface structure in faulted zone where planning and development drilling is major challenge. Thirteen 2D seismic and six well logs have been used to identify six gas bearing horizons and a network of faults and to map the structure at reservoir level. Variance attributes were used to identify faults. Velocity model is performed for domain conversion. Synthetics were prepared from two wells where sonic and density logs are available. Well to seismic tie at reservoir zone shows good match with Direct Hydrocarbon Indicator on seismic section. Vsh, porosity, water saturation and permeability have been calculated and various cross plots among porosity logs have been shown. Structural modeling is used to make zone and layering accordance with minimum sand thickness. Fault model shows the possible fault network, those liable for several dry wells. Facies model have been constrained with Sequential Indicator Simulation method to show the facies distribution along the depth surfaces. Petrophysical models have been prepared with Sequential Gaussian Simulation to estimate petrophysical parameters away from the existing wells to other parts of the field and to observe heterogeneities in reservoir. Average porosity map for each gas zone were constructed. The outcomes of the research

  18. Application of 3D reflection seismic methods to mineral exploration

    NASA Astrophysics Data System (ADS)

    Urosevic, Milovan

    2013-04-01

    Seismic exploration for mineral deposits is often tested by excessively complex structures, regolith heterogeneity, intrinsically low signal to noise ratio, ground relief and accessibility. In brown fields, where the majority of the seismic surveys have been conducted, existing infrastructure, old pits and tailings, heavy machinery in operation, mine drainage and other mine related activities are further challenging the application of seismic methods and furthermore increasing its cost. It is therefore not surprising that the mining industry has been reluctant to use seismic methods, particularly 3D for mineral exploration, primarily due to the high cost, but also because of variable performance, and in some cases ambiguous interpretation results. However, shallow mineral reserves are becoming depleted and exploration is moving towards deeper targets. Seismic methods will be more important for deeper investigations and may become the primary exploration tool in the near future. The big issue is if we have an appropriate seismic "strategy" for exploration of deep, complex mineral reserves. From the existing case histories worldwide we know that massive ore deposits (VMS, VHMS) constitute the best case scenario for the application of 3D seismic. Direct targeting of massive ore bodies from seismic has been documented in several case histories. Sediment hosted deposits could, in some cases, can also produce a detectable seismic signature. Other deposit types such as IOCG and skarn are much more challenging for the application of seismic methods. The complexity of these deposits requires new thinking. Several 3D surveys acquired over different deposit types will be presented and discussed.

  19. Crustal high-velocity anomaly at the East European Craton margin in SE Poland (TESZ) modelled by 3-D seismic tomography of refracted and reflected arrivals

    NASA Astrophysics Data System (ADS)

    Środa, Piotr; Dec, Monika

    2016-04-01

    The area of Trans-European Suture Zone in SE Poland represents a contact of major tectonic units of different consolidation age - from the Precambrian East European Craton, through Palaeozoic West European Platform to Cenozoic Carpathian orogen. The region was built by several phases of crustal accretion, which resulted in a complex collage of tectonic blocks. In 2000, this region was studied by several seismic wide-angle profiles of CELEBRATION 2000 experiment, providing a dense coverage of seismic data in SE Poland and allowing for detailed investigations of the crustal structure and properties in this area. Beneath the marginal part of the EEC, the 2-D modelling of in-line data form several CELEBRATION profiles revealed a prominent high P-wave velocity anomaly in the upper crust, with Vp of 6.7-7.1 km/s, starting at 10-16 km depth (e.g., Środa et al., 2006). Anomalously high velocities are observed in the area located approximately beneath Lublin trough, to the NE of Teisseyre-Tornquist Zone. Based on 3-D tomography of first arrivals of in- and off-line CELEBRATION 2000 recordings (Malinowski et al., 2008), elevated velocities are also reported in the same area and seem to continue to the SW, off the craton margin. Gravimetric modelling also revealed anomalously high density in the same region at similar depths. High seismic velocities and densities are interpreted as indicative for a pronounced mafic intrusion, possibly related to extensional processes at the EEC margin. Previous 3-D models of the high-velocity intrusion were based on first arrivals (crustal refractions) only. In this study, also off-line reflections (not modelled up to now) are used, in order to enlarge the data set and to better constrain the geometry and properties of the velocity anomaly. A code for 3-D joint tomographic inversion of refracted and reflected arrivals, with model parametrization allowing for velocity discontinuities was used (Rawlinson, 2007). With this approach, besides the

  20. 3-D seismic velocity and attenuation structures in the geothermal field

    SciTech Connect

    Nugraha, Andri Dian; Syahputra, Ahmad; Fatkhan,; Sule, Rachmat

    2013-09-09

    We conducted delay time tomography to determine 3-D seismic velocity structures (Vp, Vs, and Vp/Vs ratio) using micro-seismic events in the geothermal field. The P-and S-wave arrival times of these micro-seismic events have been used as input for the tomographic inversion. Our preliminary seismic velocity results show that the subsurface condition of geothermal field can be fairly delineated the characteristic of reservoir. We then extended our understanding of the subsurface physical properties through determining of attenuation structures (Qp, Qs, and Qs/Qp ratio) using micro-seismic waveform. We combined seismic velocities and attenuation structures to get much better interpretation of the reservoir characteristic. Our preliminary attanuation structures results show reservoir characterization can be more clearly by using the 3-D attenuation model of Qp, Qs, and Qs/Qp ratio combined with 3-D seismic velocity model of Vp, Vs, and Vp/Vs ratio.

  1. Lossless compression of 3D seismic data using a horizon displacement compensated 3D lifting scheme

    NASA Astrophysics Data System (ADS)

    Meftah, Anis; Antonini, Marc; Ben Amar, Chokri

    2010-01-01

    In this paper we present a method to optimize the computation of the wavelet transform for the 3D seismic data while reducing the energy of coefficients to the minimum. This allow us to reduce the entropy of the signal and so increase the compression ratios. The proposed method exploits the geometrical information contained in the seismic 3D data to optimize the computation of the wavelet transform. Indeed, the classic filtering is replaced by a filtering following the horizons contained in the 3D seismic images. Applying this approach in two dimensions permits us to obtain wavelets coefficients with lowest energy. The experiments show that our method permits to save extra 8% of the size of the object compared to the classic wavelet transform.

  2. Seismic Anisotropy and SKS Splitting in the Sangihe Subduction Zone Predicted from 3-D Mantle Flow Models

    NASA Astrophysics Data System (ADS)

    Di Leo, J. F.; Li, Z.; Walker, A. M.; Wookey, J.; Kendall, J.; Ribe, N. M.; Tommasi, A.

    2012-12-01

    Observations of shear wave splitting are often interpreted as being due to strain-induced crystal alignment of olivine in the convecting upper mantle, and the polarization of the fast shear wave is frequently taken to directly indicate the direction of mantle flow. Caution must be exercised when making such inferences, as the relationship between olivine lattice-preferred orientation (LPO) and fast direction is dependent on many factors, including the entire deformation history. This is especially the case in regions where complex time-dependent mantle flow is expected, e.g., subduction zones. Observations of shear wave splitting at subduction zones are varied, ranging from trench-perpendicular to -parallel fast directions, or a combination of both. Rigorously interpreting this variety of observations requires modeling which properly accounts for LPO development in the near-slab mantle environment. To this end, we simulate olivine LPO evolution caused by defomation of polycrystalline aggregates as they deform and move along pathlines extracted from a 3-D mantle flow model at a subduction zone (Li & Ribe, 2012). The model is based on 3-D boundary-element numerical simulations of a dense fluid sheet (representing the slab) with a geometry approximating that of the Sangihe subduction zone in Indonesia, where trench-parallel fast directions have recently been measured and ascribed to trench-parallel sub-slab mantle flow (Di Leo et al., 2012). This subduction zone is unique in that it is part of the only double-sided subduction system on Earth. At the Sangihe trench, the Molucca Sea plate is subducting westwards beneath the Eurasian plate. However, this microplate is also subducting eastwards at the nearby Halmahera trench. To test whether the measured trench-parallel fast directions are due to sub-slab mantle flow, and whether this is only possible due to the double-sided geometry, we use two different flow models: one with single- and one with double-sided subduction

  3. 3D modeling of the Buhi debris avalanche deposit of Iriga Volcano, Philippines by integrating shallow-seismic reflection and geological data

    NASA Astrophysics Data System (ADS)

    Minimo, Likha G.; Lagmay, Alfredo Mahar Francisco A.

    2016-06-01

    Numerical models for simulating volcanic debris avalanches commonly lack a critical initiation parameter, the source volume, which is difficult to estimate without data on the deposit thickness. This, in turn, limits how rheology can be characterized for simulating flow. Leapfrog Geo, a 3D geological modeling software, was used to integrate shallow-seismic reflection profiles with field and borehole data to determine the volume of the Buhi debris avalanche and the pre-collapse structure of Iriga Volcano. Volumes of the deposit calculated in this way are 34-71% larger than previous estimates. This technique may improve models of debris avalanches elsewhere in the world, and more precisely depict landslide runout and lateral extent, thus improving disaster prevention and mitigation for the many cities located near volcanoes.

  4. Method for inverting reflection trace data from 3-D and 4-D seismic surveys and identifying subsurface fluid and pathways in and among hydrocarbon reservoirs based on impedance models

    DOEpatents

    He, Wei; Anderson, Roger N.

    1998-01-01

    A method is disclosed for inverting 3-D seismic reflection data obtained from seismic surveys to derive impedance models for a subsurface region, and for inversion of multiple 3-D seismic surveys (i.e., 4-D seismic surveys) of the same subsurface volume, separated in time to allow for dynamic fluid migration, such that small scale structure and regions of fluid and dynamic fluid flow within the subsurface volume being studied can be identified. The method allows for the mapping and quantification of available hydrocarbons within a reservoir and is thus useful for hydrocarbon prospecting and reservoir management. An iterative seismic inversion scheme constrained by actual well log data which uses a time/depth dependent seismic source function is employed to derive impedance models from 3-D and 4-D seismic datasets. The impedance values can be region grown to better isolate the low impedance hydrocarbon bearing regions. Impedance data derived from multiple 3-D seismic surveys of the same volume can be compared to identify regions of dynamic evolution and bypassed pay. Effective Oil Saturation or net oil thickness can also be derived from the impedance data and used for quantitative assessment of prospective drilling targets and reservoir management.

  5. Method for inverting reflection trace data from 3-D and 4-D seismic surveys and identifying subsurface fluid and pathways in and among hydrocarbon reservoirs based on impedance models

    DOEpatents

    He, W.; Anderson, R.N.

    1998-08-25

    A method is disclosed for inverting 3-D seismic reflection data obtained from seismic surveys to derive impedance models for a subsurface region, and for inversion of multiple 3-D seismic surveys (i.e., 4-D seismic surveys) of the same subsurface volume, separated in time to allow for dynamic fluid migration, such that small scale structure and regions of fluid and dynamic fluid flow within the subsurface volume being studied can be identified. The method allows for the mapping and quantification of available hydrocarbons within a reservoir and is thus useful for hydrocarbon prospecting and reservoir management. An iterative seismic inversion scheme constrained by actual well log data which uses a time/depth dependent seismic source function is employed to derive impedance models from 3-D and 4-D seismic datasets. The impedance values can be region grown to better isolate the low impedance hydrocarbon bearing regions. Impedance data derived from multiple 3-D seismic surveys of the same volume can be compared to identify regions of dynamic evolution and bypassed pay. Effective Oil Saturation or net oil thickness can also be derived from the impedance data and used for quantitative assessment of prospective drilling targets and reservoir management. 20 figs.

  6. Regional seismic wavefield computation on a 3-D heterogeneous Earth model by means of coupled traveling wave synthesis

    USGS Publications Warehouse

    Pollitz, F.F.

    2002-01-01

    I present a new algorithm for calculating seismic wave propagation through a three-dimensional heterogeneous medium using the framework of mode coupling theory originally developed to perform very low frequency (f < ???0.01-0.05 Hz) seismic wavefield computation. It is a Greens function approach for multiple scattering within a defined volume and employs a truncated traveling wave basis set using the locked mode approximation. Interactions between incident and scattered wavefields are prescribed by mode coupling theory and account for the coupling among surface waves, body waves, and evanescent waves. The described algorithm is, in principle, applicable to global and regional wave propagation problems, but I focus on higher frequency (typically f ??????0.25 Hz) applications at regional and local distances where the locked mode approximation is best utilized and which involve wavefields strongly shaped by propagation through a highly heterogeneous crust. Synthetic examples are shown for P-SV-wave propagation through a semi-ellipsoidal basin and SH-wave propagation through a fault zone.

  7. Delineating Potential Quick-clay Areas Using High-resolution Seismic Methods: Towards a 3D Model of an Area Prone to Slide in SW Sweden

    NASA Astrophysics Data System (ADS)

    Salas Romero, S.; Malehmir, A.; Snowball, I.

    2015-12-01

    Quick clay can liquefy under increased stress and is responsible for major landslides in Sweden, Norway and Canada, but despite extensive investigations delineating quick clay remains a challenge. As part of a large multidisciplinary project, this study focuses on an area prone to quick-clay landslides in SW Sweden. P- and S-wave seismic, electrical resistivity tomography, and RMT (radio-magnetotelluric) data obtained in 2011 (Malehmir et al. 2013) suggested the presence of a coarse-grained layer of variable thickness sandwiched between clays, with quick clay above. The coarse-grained layer was assumed to accelerate the formation of quick clay, influencing its thickness. Additional geophysical data (reflection and refraction seismic, and RMT) and studies of three boreholes drilled in 2013, with the aim to intersect the coarse-grained layer, extended the area covered in 2011. Here we report on four seismic profiles (total length 3.5 km) acquired in 2013, combined with side-scan and single channel reflection seismic data along a river, which was believed to be important in the context of quick-clay landslides. Wireless (50-1C-10 Hz and 24-3C-broadband) and cabled sensors (323-28 Hz), 4-10 m apart, were used for the data acquisition of the longest profile (nearly 2 km long). Dynamite, accelerated weight-drop and sledgehammer were used as seismic sources. Simultaneous data acquisition for two parallel profiles, about 300 m apart, provides additional information. Preliminary results delineate the bedrock and its undulation near and in the river. We believe that overlying reflections are caused by the coarse-grained materials, whose lateral extension is considerably larger than previously thought. This may imply a wider area containing quick clay and hence at risk of slope failure. The new data and previous results are combined to construct a high-resolution 3D subsurface model that focuses on the coarse-grained layer and potential quick-clay areas. Malehmir A, Bastani M

  8. Making Inexpensive 3-D Models

    ERIC Educational Resources Information Center

    Manos, Harry

    2016-01-01

    Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the "TPT" theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity…

  9. Using Averaging-Based Factorization to Compare Seismic Hazard Models Derived from 3D Earthquake Simulations with NGA Ground Motion Prediction Equations

    NASA Astrophysics Data System (ADS)

    Wang, F.; Jordan, T. H.

    2012-12-01

    Seismic hazard models based on empirical ground motion prediction equations (GMPEs) employ a model-based factorization to account for source, propagation, and path effects. An alternative is to simulate these effects directly using earthquake source models combined with three-dimensional (3D) models of Earth structure. We have developed an averaging-based factorization (ABF) scheme that facilitates the geographically explicit comparison of these two types of seismic hazard models. For any fault source k with epicentral position x, slip spatial and temporal distribution f, and moment magnitude m, we calculate the excitation functions G(s, k, x, m, f) for sites s in a geographical region R, such as 5% damped spectral acceleration at a particular period. Through a sequence of weighted-averaging and normalization operations following a certain hierarchy over f, m, x, k, and s, we uniquely factorize G(s, k, x, m, f) into six components: A, B(s), C(s, k), D(s, k, x), E(s, k, x, m), and F(s, k, x, m, f). Factors for a target model can be divided by those of a reference model to obtain six corresponding factor ratios, or residual factors: a, b(s), c(s, k), d(s, k, x), e(s, k, x, m), and f(s, k, x, m, f). We show that these residual factors characterize differences in basin effects primarily through b(s), distance scaling primarily through c(s, k), and source directivity primarily through d(s, k, x). We illustrate the ABF scheme by comparing CyberShake Hazard Model (CSHM) for the Los Angeles region (Graves et. al. 2010) with the Next Generation Attenuation (NGA) GMPEs modified according to the directivity relations of Spudich and Chiou (2008). Relative to CSHM, all NGA models underestimate the directivity and basin effects. In particular, the NGA models do not account for the coupling between source directivity and basin excitation that substantially enhance the low-frequency seismic hazards in the sedimentary basins of the Los Angeles region. Assuming Cyber

  10. 3-D seismic exploration in the Ames hole

    SciTech Connect

    Ainsworth, K.R.

    1995-09-01

    The Ames Crater of Major County, Oklahoma has been one of the more controversial drilling projects to emerge in the Mid-Continent province in this decade. Within the crater, dolomitic and granodiorite breccias produce substantial quantities of oil and gas within structurally controlled accumulations. To understand the structural complexities of the crater, Continental Resources, in partnership with other Ames operators, acquired 3-D seismic data in four separate acquisition projects across various exploratory and development projects across the crater. Integrated seismic and subsurface control revealed four separate features within the principal crater floor oil and gas accumulation. Using the 3-D data as a lead tool, these companies identified and developed a significant number of commercial tests within the limits of the seismic surveys. Although the tool generally proved to be successful, reservoir variability, velocity variations, and interpretational errors resulted in some non-commercial and dry tests.

  11. How 3-D, 3-C seismic characterized a carbonate reservoir

    SciTech Connect

    Arestad, J.F.; Mattocks, B.W.; Davis, T.L.; Benson, R.D.

    1995-04-01

    The Reservoir Characterization Project (RCP) at the Colorado School of Mines has pioneered research into 3-D, 3-C (multicomponent) reflection seismology for nearly a decade utilizing both P-wave and S-wave sources. Multicomponent-seismic surveys provide significantly more information about petroleum reservoirs than compressional-wave surveys. Initial 3-D, 3-C surveys acquired by RCP were targeted at characterizing naturally fractured reservoirs. The current phase of the project is oriented towards utilizing shear waves to discriminate lithologic and diagenetic changes within stratigraphic reservoirs where compressional-seismic data has not be effective. The Joffre field, Nisku reservoir, is the site of RCP`s ongoing multidisciplinary research effort in Western Canada. The research team is directed by Colorado School of Mines faculty with graduate team members from geology, geophysics and petroleum engineering departments. While this study is still in progress, some key findings and directions of this research are reported here. The following topics will be discussed: Joffre field 3-D, 3-C survey; compressional wave 3-D technique; shear-wave 3-D technique; converted-wave 3-D technique; reservoir characterization, and future directions.

  12. The Updated LLNL-G3D Global P-Wave Velocity Model and Its Performance in Seismic Event Location

    DTIC Science & Technology

    2011-09-01

    in our previous reports) and sharp details of subducted slabs around the world. Based on preliminary relocation tests, using LLNL-G3Dv2 travel-time...details of subducted slabs around the world. Based on preliminary relocation tests, using LLNL-G3Dv2 travel-time predictions typically reduces...simultaneously. In addition, sensitivity is spread across broad depth zones and/or multiple model units to mitigate the issue of path-velocity

  13. Time-lapse 3-D seismic imaging of shallow subsurface contaminant flow.

    PubMed

    McKenna, J; Sherlock, D; Evans, B

    2001-12-01

    This paper presents a physical modelling study outlining a technique whereby buoyant contaminant flow within water-saturated unconsolidated sand was remotely monitored utilizing the time-lapse 3-D (TL3-D) seismic response. The controlled temperature and pressure conditions, along with the high level of acquisition repeatability attainable using sandbox physical models, allow the TL3-D seismic response to pore fluid movement to be distinguished from all other effects. TL3-D seismic techniques are currently being developed to monitor hydrocarbon reserves within producing reservoirs in an endeavour to improve overall recovery. However, in many ways, sandbox models under atmospheric conditions more accurately simulate the shallow subsurface than petroleum reservoirs. For this reason, perhaps the greatest application for analogue sandbox modelling is to improve our understanding of shallow groundwater and environmental flow mechanisms. Two fluid flow simulations were conducted whereby air and kerosene were injected into separate water-saturated unconsolidated sand models. In both experiments, a base 3-D seismic volume was recorded and compared with six later monitor surveys recorded while the injection program was conducted. Normal incidence amplitude and P-wave velocity information were extracted from the TL3-D seismic data to provide visualization of contaminant migration. Reflection amplitudes displayed qualitative areal distribution of fluids when a suitable impedance contrast existed between pore fluids. TL3-D seismic reflection tomography can potentially monitor the change in areal distribution of fluid contaminants over time, indicating flow patterns. However, other research and this current work have not established a quantifiable relationship between either normal reflection amplitudes and attenuation and fluid saturation. Generally, different pore fluids will have unique seismic velocities due to differences in compressibility and density. The predictable

  14. NORTH HILL CREEK 3-D SEISMIC EXPLORATION PROJECT

    SciTech Connect

    Marc T. Eckels; David H. Suek; Denise H. Harrison; Paul J. Harrison

    2004-05-06

    Wind River Resources Corporation (WRRC) received a DOE grant in support of its proposal to acquire, process and interpret fifteen square miles of high-quality 3-D seismic data on non-allotted trust lands of the Uintah and Ouray (Ute) Indian Reservation, northeastern Utah, in 2000. Subsequent to receiving notice that its proposal would be funded, WRRC was able to add ten square miles of adjacent state and federal mineral acreage underlying tribal surface lands by arrangement with the operator of the Flat Rock Field. The twenty-five square mile 3-D seismic survey was conducted during the fall of 2000. The data were processed through the winter of 2000-2001, and initial interpretation took place during the spring of 2001. The initial interpretation identified multiple attractive drilling prospects, two of which were staked and permitted during the summer of 2001. The two initial wells were drilled in September and October of 2001. A deeper test was drilled in June of 2002. Subsequently a ten-well deep drilling evaluation program was conducted from October of 2002 through March 2004. The present report discusses the background of the project; design and execution of the 3-D seismic survey; processing and interpretation of the data; and drilling, completion and production results of a sample of the wells drilled on the basis of the interpreted survey. Fifteen wells have been drilled to test targets identified on the North Hill Creek 3-D Seismic Survey. None of these wildcat exploratory wells has been a dry hole, and several are among the best gas producers in Utah. The quality of the data produced by this first significant exploratory 3-D survey in the Uinta Basin has encouraged other operators to employ this technology. At least two additional 3-D seismic surveys have been completed in the vicinity of the North Hill Creek Survey, and five additional surveys are being planned for the 2004 field season. This project was successful in finding commercial oil, natural gas

  15. 3D Seismic Reflection Experiment over the Galicia Deep Basin

    NASA Astrophysics Data System (ADS)

    Sawyer, D. S.; Jordan, B.; Reston, T. J.; Minshull, T. A.; Klaeschen, D.; Ranero, C.; Shillington, D. J.; Morgan, J. K.

    2014-12-01

    In June thru September, 2013, a 3D reflection and a long offset seismic experiment were conducted at the Galicia rifted margin by investigators from the US, UK, Germany, and Spain. The 3D multichannel experiment covered 64 km by 20 km (1280 km2), using the RV Marcus Langseth. Four streamers 6 km long were deployed at 12.5 m hydrophone channel spacing. The streamers were 200 m apart. Two airgun arrays, each 3300 cu in, were fired alternately every 37.5 m, to collectively yield a 400 m wide sail line consisting of 8 CMP lines at 50 m spacing. The long offset seismic experiment included 72 short period OBS's deployed below the 3D reflection survey box. Most of the instruments recorded all the shots from the airgun array shots. The 3D seismic box covered a variety of geologic features. The Peridotite Ridge (PR), is associated with the exhumation of upper mantle rocks to the seafloor during the final stage of the continental separation between the Galicia Bank and the Grand Banks of Newfoundland. The S reflector is present below most of the continental blocks under the deep Galicia basin. S is interpreted to be a low-angle detachment fault formed late in the rifting process, and a number of rotated fault block basins and ranges containing pre and syn-rift sediments. Initial observations from stacked 3D seismic data, and samples of 2D pre-stack time migrated (PSTM) 3D seismic data show that the PR is elevated above the present seafloor in the South and not exposed through the seafloor in the North. The relative smoothness of the PR surface for the entire 20 km N-S contrasts with the more complex, shorter wavelength, faulting of the continental crustal blocks to the east. The PR does not seem to show offsets or any apparent internal structure. The PSTM dip lines show substantial improvement for the structures in the deep sedimentary basin East of the PR. These seem to extend the S reflector somewhat farther to the West. The migrated data show a substantial network of

  16. Seismic random noise attenuation via 3D block matching

    NASA Astrophysics Data System (ADS)

    Amani, Sajjad; Gholami, Ali; Javaheri Niestanak, Alireza

    2017-01-01

    The lack of signal to noise ratio increases the final errors of seismic interpretation. In the present study, we apply a new non-local transform domain method called "3 Dimensional Block Matching (3DBM)" for seismic random noise attenuation. Basically, 3DBM uses the similarities through the data for retrieving the amplitude of signal in a specific point in the f-x domain, and because of this, it is able to preserve discontinuities in the data such as fractures and faults. 3DBM considers each seismic profile as an image and thus it can be applied to both pre-stack and post-stack seismic data. It uses the block matching clustering method to gather similar blocks contained in 2D data into 3D groups in order to enhance the level of correlation in each 3D array. By applying a 2D transform and 1D transform (instead of a 3D transform) on each array, we can effectively attenuate the noise by shrinkage of the transform coefficients. The subsequent inverse 2D transform and inverse 1D transform yield estimates of all matched blocks. Finally, the random noise attenuated data is computed using the weighted average of all block estimates. We applied 3DBM on both synthetic and real pre-stack and post-stack seismic data and compared it with a Curvelet transform based denoising method which is one of the most powerful methods in this area. The results show that 3DBM method eventuates in higher signal to noise ratio, lower execution time and higher visual quality.

  17. Recovering physical property information from subduction plate boundaries using 3D full-waveform seismic inversion

    NASA Astrophysics Data System (ADS)

    Bell, R. E.; Morgan, J. V.; Warner, M.

    2013-12-01

    Our understanding of subduction margin seismogenesis has been revolutionised in the last couple of decades with the discovery that the size of the seismogenic zone may not be controlled simply by temperature and a broad spectrum of seismic behaviour exists from stick-slip to stable sliding. Laboratory and numerical experiments suggest that physical properties, particularly fluid pressure may play an important role in controlling the seismic behaviour of subduction margins. Although drilling can provide information on physical properties along subduction thrust faults at point locations at relatively shallow depths, correlations between physical properties and seismic velocity using rock physics relationships are required to resolve physical properties along the margin and down-dip. Therefore, high resolution seismic velocity models are key to recovering physical property information at subduction plate boundaries away from drill sites. 3D Full waveform inversion (FWI) is a technique pioneered by the oil industry to obtain high-resolution high-fidelity models of physical properties in the sub-surface. 3D FWI involves the inversion of low-frequency (>2 to <7 Hz), early arriving (principally transmitted) seismic data, to recover the macro (intermediate to long-wavelength) velocity structure. Although 2D FWI has been used to improve velocity models of subduction plate boundaries before, 3D FWI has not yet been attempted. 3D inversions have superior convergence and accuracy, as they sample the subsurface with multi-azimuth multiply-crossing wavefields. In this contribution we perform a suite of synthetic tests to investigate if 3D FWI could be used to better resolve physical property information along subduction margin plate boundaries using conventionally collected 3D seismic data. We base our analysis on the Muroto Basin area of the Nankai margin and investigate if the acquisition parameters and geometry of the subduction margin render 3D seismic data collected across

  18. Making Inexpensive 3-D Models

    NASA Astrophysics Data System (ADS)

    Manos, Harry

    2016-03-01

    Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the TPT theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity well tailored to specific class lessons. Most of the supplies are readily available in the home or at school: rubbing alcohol, a rag, two colors of spray paint, art brushes, and masking tape. The cost of these supplies, if you don't have them, is less than 20.

  19. 3D Seismic Reflection Experiment Over the Galicia Deep Basin

    NASA Astrophysics Data System (ADS)

    Sawyer, Dale; Jordan, Brian; Tesi Sanjurjo, Mari; Alexanian, Ara; Morgan, Julia; Shillington, Donna; Reston, Timothy; Minshull, Timothy; Klaeschen, Dirk; Ranero, César

    2014-05-01

    In June thru September, 2013, a 3D reflection and a long offset seismic experiment were conducted at the Galicia rifted margin by investigators from the US, UK, Germany, and Spain. The 3D multichannel experiment covered 64 km by 20 km (1280 km2), using the RV Marcus Langseth. Four streamers 6 km long were deployed at 12.5 m hydrophone channel spacing. The streamers were 200 m apart. Two airgun arrays, each 3300 cu in, were fired alternately every 37.5 m, to collectively yield a 400 m wide sail line consisting of 8 CMP lines at 50 m spacing. The long offset seismic experiment included 72 short period OBS's deployed below the 3D reflection survey box. Most of the instruments recorded all the shots from the airgun array shots. The 3D seismic box covered a variety of geologic features. The Peridotite Ridge (PR), is associated with the exhumation of upper mantle rocks to the seafloor during the final stage of the continental separation between the Galicia Bank and the Grand Banks of Newfoundland. The S reflector is present below most of the continental blocks under the deep Galicia basin. S is interpreted to be a low-angle detachment fault formed late in the rifting process, and a number of rotated fault block basins and ranges containing pre and syn-rift sediments. Initial observations from stacked, but not yet migrated, 3D seismic data show that the PR is elevated above the present seafloor in the South and not exposed through the seafloor in the North. The relative smoothness of the PR surface for the entire 20 km N-S contrasts with the more complex, shorter wavelength, faulting of the continental crustal blocks to the east. The PR does not seem to show offsets or any apparent internal structure. However, migration will be required to see internal structure of the PR. Between the PR and the western most rifted continental crustal blocks, is a sedimentary basin about as wide as the PR and very different from the sedimentary basins bounded by the continental crustal

  20. Exploration 3-D Seismic Field Test/Native Tribes Initiative

    SciTech Connect

    Carroll, Herbert B.; Chen, K.C.; Guo, Genliang; Johnson, W.I.; Reeves,T.K.; Sharma,Bijon

    1999-04-27

    To determine current acquisition procedures and costs and to further the goals of the President's Initiative for Native Tribes, a seismic-survey project is to be conducted on Osage tribal lands. The goals of the program are to demonstrate the capabilities, costs, and effectiveness of 3-D seismic work in a small-operator setting and to determine the economics of such a survey. For these purposes, typical small-scale independent-operator practices are being followed and a shallow target chose in an area with a high concentration of independent operators. The results will be analyzed in detail to determine if there are improvements and/or innovations which can be easily introduced in field-acquisition procedures, in processing, or in data manipulation and interpretation to further reduce operating costs and to make the system still more active to the small-scale operator.

  1. Exploring the seismic expression of fault zones in 3D seismic volumes

    NASA Astrophysics Data System (ADS)

    Iacopini, D.; Butler, R. W. H.; Purves, S.; McArdle, N.; De Freslon, N.

    2016-08-01

    Mapping and understanding distributed deformation is a major challenge for the structural interpretation of seismic data. However, volumes of seismic signal disturbance with low signal/noise ratio are systematically observed within 3D seismic datasets around fault systems. These seismic disturbance zones (SDZ) are commonly characterized by complex perturbations of the signal and occur at the sub-seismic (10 s m) to seismic scale (100 s m). They may store important information on deformation distributed around those larger scale structures that may be readily interpreted in conventional amplitude displays of seismic data. We introduce a method to detect fault-related disturbance zones and to discriminate between this and other noise sources such as those associated with the seismic acquisition (footprint noise). Two case studies from the Taranaki basin and deep-water Niger delta are presented. These resolve SDZs using tensor and semblance attributes along with conventional seismic mapping. The tensor attribute is more efficient in tracking volumes containing structural displacements while structurally-oriented semblance coherency is commonly disturbed by small waveform variations around the fault throw. We propose a workflow to map and cross-plot seismic waveform signal properties extracted from the seismic disturbance zone as a tool to investigate the seismic signature and explore seismic facies of a SDZ.

  2. Exploring the seismic expression of fault zones in 3D seismic volumes

    NASA Astrophysics Data System (ADS)

    Iacopini, David; Butler, Rob; Purves, Steve

    2016-04-01

    Mapping and understanding distributed deformation is a major challenge for the structural interpretation of seismic data. However, volumes of seismic signal disturbance with low signal/noise ratio are systematically observed within 3D seismic datasets around fault systems. These seismic disturbance zones (SDZ) are commonly characterized by complex perturbations of the signal and occur at the sub-seismic to seismic scale. They may store important information on deformation distributed around those larger scale structures that may be readily interpreted in conventional amplitude displays of seismic data scale. We introduce a method to detect fault-related disturbance zones and to discriminate between this and other noise sources such as those associated with the seismic acquisition (footprint noise). Two case studies, from the Taranaki basin and deep-water Niger delta are presented. These resolve structure within SDZs using tensor and semblance attributes along with conventional seismic mapping. The tensor attribute is more efficient in tracking volumes containing structural displacements while structurally-oriented semblance coherency is commonly disturbed by small waveform variations around the fault throw. We propose a workflow to map and cross-plot seismic waveform signal properties extracted from the seismic disturbance zone as a tool to investigate the seismic signature and explore seismic facies of a SDZ.

  3. Crowdsourcing Based 3d Modeling

    NASA Astrophysics Data System (ADS)

    Somogyi, A.; Barsi, A.; Molnar, B.; Lovas, T.

    2016-06-01

    Web-based photo albums that support organizing and viewing the users' images are widely used. These services provide a convenient solution for storing, editing and sharing images. In many cases, the users attach geotags to the images in order to enable using them e.g. in location based applications on social networks. Our paper discusses a procedure that collects open access images from a site frequently visited by tourists. Geotagged pictures showing the image of a sight or tourist attraction are selected and processed in photogrammetric processing software that produces the 3D model of the captured object. For the particular investigation we selected three attractions in Budapest. To assess the geometrical accuracy, we used laser scanner and DSLR as well as smart phone photography to derive reference values to enable verifying the spatial model obtained from the web-album images. The investigation shows how detailed and accurate models could be derived applying photogrammetric processing software, simply by using images of the community, without visiting the site.

  4. 3D Seismic Imaging over a Potential Collapse Structure

    NASA Astrophysics Data System (ADS)

    Gritto, Roland; O'Connell, Daniel; Elobaid Elnaiem, Ali; Mohamed, Fathelrahman; Sadooni, Fadhil

    2016-04-01

    The Middle-East has seen a recent boom in construction including the planning and development of complete new sub-sections of metropolitan areas. Before planning and construction can commence, however, the development areas need to be investigated to determine their suitability for the planned project. Subsurface parameters such as the type of material (soil/rock), thickness of top soil or rock layers, depth and elastic parameters of basement, for example, comprise important information needed before a decision concerning the suitability of the site for construction can be made. A similar problem arises in environmental impact studies, when subsurface parameters are needed to assess the geological heterogeneity of the subsurface. Environmental impact studies are typically required for each construction project, particularly for the scale of the aforementioned building boom in the Middle East. The current study was conducted in Qatar at the location of a future highway interchange to evaluate a suite of 3D seismic techniques in their effectiveness to interrogate the subsurface for the presence of karst-like collapse structures. The survey comprised an area of approximately 10,000 m2 and consisted of 550 source- and 192 receiver locations. The seismic source was an accelerated weight drop while the geophones consisted of 3-component 10 Hz velocity sensors. At present, we analyzed over 100,000 P-wave phase arrivals and performed high-resolution 3-D tomographic imaging of the shallow subsurface. Furthermore, dispersion analysis of recorded surface waves will be performed to obtain S-wave velocity profiles of the subsurface. Both results, in conjunction with density estimates, will be utilized to determine the elastic moduli of the subsurface rock layers.

  5. Seismic waves in 3-D: from mantle asymmetries to reliable seismic hazard assessment

    NASA Astrophysics Data System (ADS)

    Panza, Giuliano F.; Romanelli, Fabio

    2014-10-01

    A global cross-section of the Earth parallel to the tectonic equator (TE) path, the great circle representing the equator of net lithosphere rotation, shows a difference in shear wave velocities between the western and eastern flanks of the three major oceanic rift basins. The low-velocity layer in the upper asthenosphere, at a depth range of 120 to 200 km, is assumed to represent the decoupling between the lithosphere and the underlying mantle. Along the TE-perturbed (TE-pert) path, a ubiquitous LVZ, about 1,000-km-wide and 100-km-thick, occurs in the asthenosphere. The existence of the TE-pert is a necessary prerequisite for the existence of a continuous global flow within the Earth. Ground-shaking scenarios were constructed using a scenario-based method for seismic hazard analysis (NDSHA), using realistic and duly validated synthetic time series, and generating a data bank of several thousands of seismograms that account for source, propagation, and site effects. Accordingly, with basic self-organized criticality concepts, NDSHA permits the integration of available information provided by the most updated seismological, geological, geophysical, and geotechnical databases for the site of interest, as well as advanced physical modeling techniques, to provide a reliable and robust background for the development of a design basis for cultural heritage and civil infrastructures. Estimates of seismic hazard obtained using the NDSHA and standard probabilistic approaches are compared for the Italian territory, and a case-study is discussed. In order to enable a reliable estimation of the ground motion response to an earthquake, three-dimensional velocity models have to be considered, resulting in a new, very efficient, analytical procedure for computing the broadband seismic wave-field in a 3-D anelastic Earth model.

  6. Prestack reverse time migration for 3D marine reflection seismic data

    SciTech Connect

    Jang, Seonghyung; Kim, Taeyoun

    2015-03-10

    Prestack reverse time migration (RTM) is a method for imaging the subsurface using the inner product of wavefield extrapolation in shot domain and in receiver domain. It is well known that RTM is better for preserving amplitudes and phases than other prestack migrations. Since 3D seismic data is huge data volume and it needs heavy computing works, it requires parallel computing in order to have a meaningful depth image of the 3D subsurface. We implemented a parallelized version of 3D RTM for prestack depth migration. The results of numerical example for 3D SEG/EAGE salt model showed good agreement with the original geological model. We applied RTM to offshore 3D seismic reflection data. The study area is 12 × 25 km with 120 survey lines. Shot and receiver spacing is 25 m and 12.5 m. The line spacing is 100 m. Shot gathers were preprocessed to enhance signal to noise ratio and velocity model was calculated from conventional stack velocity. Both of them were used to obtain 3D image using RTM. The results show reasonable subsurface image.

  7. Modeling and Processing of Continuous 3D Elastic Wavefield Data

    NASA Astrophysics Data System (ADS)

    Milkereit, B.; Bohlen, T.

    2001-12-01

    Continuous seismic wavefields are excited by earthquake clustering, induced seismicity in reservoirs, and mining. In hydrocarbon reservoirs, for example, pore pressure changes and fluid flow (mass transfer) will cause incremental deviatoric stresses sufficient to trigger and sustain seismic activity. Here we address three aspects of seismic wavefields in three-dimensional heterogeneous media triggered by distributed sources in space and time: forward modeling, multichannel data processing, and source location imaging. A power law distribution of seismic sources (such as the Gutenberg-Richter law) is used for the modeling of viscoelastic/elastic wave propagation through a realistic earth model. 3D modeling provides new insight in the interaction of multi-source wavefields and the role of scale-dependend elastic model parameters on transmitted and reflected/back-scattered wavefields. There exists a strong correlation between the spatial properties of the compressional, shear wave and density perturbations and the lateral correlation length of the resulting reflected or transmitted seismic wavefields. Modeling is based on the implementation of 3D elastic/viscoelastic FD codes on massive parallel and/or distributed computing resources using MPI (message passing interface). For parallelization, large grid 3D earth models are decomposed into subvolume processing elements whereby each processing element is updating the wavefield within its portion of the grid. Processing of continuous seismic wavefields excited by multiple distributed sources is based on a combination of crosscorrelated or slowness-transformed array data and Kirchhoff or reverse time migration for source location or source volume imaging. The appearance of slowness in both migration and array data processing suggests the possibility of combining them into a single process. In order to place further constraints on the migration, the directivity properties of 3-component receiver arrays can be included in

  8. High Resolution Near Surface 3D Seismic Experiments: A Carbonate Platform vs. a Siliciclastic Sequence

    NASA Astrophysics Data System (ADS)

    Filippidou, N.; Drijkoningen, G.; Braaksma, H.; Verwer, K.; Kenter, J.

    2005-05-01

    Interest in high-resolution 3D seismic experiments for imaging shallow targets has increased over the past years. Many case studies presented, show that producing clear seismic images with this non-evasive method, is still a challenge. We use two test-sites where nearby outcrops are present so that an accurate geological model can be built and the seismic result validated. The first so-called natural field laboratory is located in Boulonnais (N. France). It is an upper Jurassic siliciclastic sequence; age equivalent of the source rock of N. Sea. The second one is located in Cap Blanc,to the southwest of the Mallorca island(Spain); depicting an excellent example of Miocene prograding reef platform (Llucmajor Platform); it is a textbook analog for carbonate reservoirs. In both cases, the multidisciplinary experiment included the use of multicomponent and quasi- or 3D seismic recordings. The target depth does not exceed 120m. Vertical and shear portable vibrators were used as source. In the center of the setups, boreholes were drilled and Vertical Seismic Profiles were shot, along with core and borehole measurements both in situ and in the laboratory. These two geologically different sites, with different seismic stratigraphy have provided us with exceptionally high resolution seismic images. In general seismic data was processed more or less following standard procedures, a few innovative techniques on the Mallorca data, as rotation of horizontal components, 3D F-K filter and addition of parallel profiles, have improved the seismic image. In this paper we discuss the basic differences as seen on the seismic sections. The Boulonnais data present highly continuous reflection patterns of extremenly high resolution. This facilitated a high resolution stratigraphic description. Results from the VSP showed substantial wave energy attenuation. However, the high-fold (330 traces ) Mallorca seismic experiment returned a rather discontinuous pattern of possible reflectors

  9. Structural interpretation of upper crust of the Khibiny area on the complex of geological and geophysical data and the results of 3D seismic and density modeling

    NASA Astrophysics Data System (ADS)

    Zhirov, Dmitry; Glaznev, Victor; Zhirova, Anzhela

    2015-04-01

    The area considered is located in the central part of the Kola Peninsula and represents a part of tectonically compound terrane, consisting of the AR, PR and PZ geological structures of the East of Fennoscandian shield (NW Russia). The Khibiny massif (PZ) intrudes the Archean complexes (the northern contact) and the Paleoproterozoic volcanogenic-sedimentary Imandra-Varzuga complex (southern and SW-contacts). Moreover this district includes several PGE-bearing layered mafic-ultramafic intrusions, which are related with Neo Archaean ÷ Paleoproterozoic rifting and plume activity (LIP). According to the previous conceptions the shape of the Khibiny multiphase pluton is close to the asymmetrical lopolit, characterized by the steep eastern and northern contacts and the gentler south and west contacts. The results of the 3D seismic and density modelling showed two correlated local high-velocity and high-density anomalies with dimensions of 5 x 10 km approximately in central part of the Khibiny massif (1) and close to contact with Imandra-Varzuga sedimentary-volcanic complex (2). The first anomaly cannot be explained by "substance" factor only (titanomagnetite-apatite ore bodies), as it has a structural disconformity to general structure of the pluton. According to the numerous instrumental measurements the actual values of stress are significantly greater than values calculated by weight of rocks. It is important the main normal axis of compressive stress has usually quasi-horizontal position. Thus, the zone of abnormally high tectonic stress is the best explanation for this anomaly. The quick isostatic uplift of the massif after the digression of the last glacier, during which the rocks did not have time to unload, can be a source of the increased horizontal stress. Based on the properties of typical rocks and geological structure of the region the second anomaly is well interpreted by large layered intrusion of Fedorova-Pana type, subsurface of which is cut by Khibiny

  10. Reservoir geology using 3D modelling tools

    SciTech Connect

    Dubrule, O.; Samson, P.; Segonds, D.

    1996-12-31

    The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological {open_quotes}objects{close_quotes} with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.

  11. Reservoir geology using 3D modelling tools

    SciTech Connect

    Dubrule, O. ); Samson, P. ); Segonds, D. )

    1996-01-01

    The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological [open quotes]objects[close quotes] with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.

  12. Tomography 3D models of S wave from cross-correlation of seismic noise to explore irregularities of subsoil under the artificial lake of Chapultepec Park

    NASA Astrophysics Data System (ADS)

    Cárdenas-Soto, M.; Valdes, J. E.; Escobedo-Zenil, D.

    2013-05-01

    In June 2006, the base of the artificial lake in Chapultepec Park collapsed. 20 thousand liters of water were filtered to the ground through a crack increasing the dimensions of initial gap. Studies indicated that the collapse was due to saturated material associated with a sudden and massive water filtration process. Geological studies indicates that all the area of this section the subsoil is composed of vulcano-sedimentary materials that were economically exploited in the mid-20th century, leaving a series of underground mines that were rehabilitated for the construction of the Park. Currently, the Lake is rehabilitated and running for recreational activities. In this study we have applied two methods of seismic noise correlation; seismic interferometry (SI) in time domain and the Spatial Power Auto Correlation (SPAC) in frequency domain, in order to explore the 3D subsoil velocity structure. The aim is to highlight major variations in velocity that can be associated with irregularities in the subsoil that may pose a risk to the stability of the Lake. For this purpose we use 96 vertical geophones of 4.5 Hz with 5-m spacing that conform a semi-circular array that provide a length of 480 m around the lake zone. For both correlation methods, we extract the phase velocity associated with the dispersion characteristics between each pair of stations in the frequency range from 4 to 12 Hz. In the SPAC method the process was through the dispersion curve, and in SI method we use the time delay of the maximum amplitude in the correlation pulse, which was previously filtered in multiple frequency bands. The results of both processes were captured in 3D velocity volumes (in the case SI a process of traveltime tomography was applied). We observed that in the frequency range from 6 to 8 Hz, appear irregular structures, with high velocity contrast in relation with the shear wave velocity of surface layer (ten thick m of saturated sediments). One of these anomalies is related

  13. 3-D seismic response of buried pipelines laid through fault

    SciTech Connect

    Liang, J.W.

    1995-12-31

    An ideal model for the non-causative fault is put forward in which the fault is assumed to be composed by three horizontally adjacent soil media. Dynamic behaviors of pipelines laid through the fault is analyzed. Although simple, this model may qualitatively illustrate the accumulation of seismic waves in the fault, so illustrate the dynamic behaviors of the pipelines. The results show that, the fault is materially different from a two soil site even if the fault width is very narrow, and the dynamic behaviors of the pipelines laid through the fault are determined by the fault width, the stiffness ratio of the three soil media, and the type of the seismic waves.

  14. Integrating 3D seismic curvature and curvature gradient attributes for fracture characterization: Methodologies and interpretational implications

    SciTech Connect

    Gao, Dengliang

    2013-03-01

    In 3D seismic interpretation, curvature is a popular attribute that depicts the geometry of seismic reflectors and has been widely used to detect faults in the subsurface; however, it provides only part of the solutions to subsurface structure analysis. This study extends the curvature algorithm to a new curvature gradient algorithm, and integrates both algorithms for fracture detection using a 3D seismic test data set over Teapot Dome (Wyoming). In fractured reservoirs at Teapot Dome known to be formed by tectonic folding and faulting, curvature helps define the crestal portion of the reservoirs that is associated with strong seismic amplitude and high oil productivity. In contrast, curvature gradient helps better define the regional northwest-trending and the cross-regional northeast-trending lineaments that are associated with weak seismic amplitude and low oil productivity. In concert with previous reports from image logs, cores, and outcrops, the current study based on an integrated seismic curvature and curvature gradient analysis suggests that curvature might help define areas of enhanced potential to form tensile fractures, whereas curvature gradient might help define zones of enhanced potential to develop shear fractures. In certain fractured reservoirs such as at Teapot Dome where faulting and fault-related folding contribute dominantly to the formation and evolution of fractures, curvature and curvature gradient attributes can be potentially applied to differentiate fracture mode, to predict fracture intensity and orientation, to detect fracture volume and connectivity, and to model fracture networks.

  15. Investigation of surface wave amplitudes in 3-D velocity and 3-D Q models

    NASA Astrophysics Data System (ADS)

    Ruan, Y.; Zhou, Y.

    2010-12-01

    It has been long recognized that seismic amplitudes depend on both wave speed structures and anelasticity (Q) structures. However, the effects of lateral heterogeneities in wave speed and Q structures on seismic amplitudes has not been well understood. We investigate the effects of 3-D wave speed and 3-D anelasticity (Q) structures on surface-wave amplitudes based upon wave propagation simulations of twelve globally-distributed earthquakes and 801 stations in Earth models with and without lateral heterogeneities in wave speed and anelasticity using a Spectral Element Method (SEM). Our tomographic-like 3-D Q models are converted from a velocity model S20RTS using a set of reasonable mineralogical parameters, assuming lateral perturbations in both velocity and Q are due to temperature perturbations. Surface-wave amplitude variations of SEM seismograms are measured in the period range of 50--200 s using boxcar taper, cosine taper and Slepian multi-tapers. We calculate ray-theoretical predictions of surface-wave amplitude perturbations due to elastic focusing, attenuation, and anelastic focusing which respectively depend upon the second spatial derivative (''roughness'') of perturbations in phase velocity, 1/Q, and the roughness of perturbations in 1/Q. Both numerical experiments and theoretical calculations show that (1) for short-period (~ 50 s) surface waves, the effects of amplitude attenuation due to 3-D Q structures are comparable with elastic focusing effects due to 3-D wave speed structures; and (2) for long-period (> 100 s) surface waves, the effects of attenuation become much weaker than elastic focusing; and (3) elastic focusing effects are correlated with anelastic focusing at all periods due to the correlation between velocity and Q models; and (4) amplitude perturbations are depend on measurement techniques and therefore cannot be directly compared with ray-theoretical predictions because ray theory does not account for the effects of measurement

  16. Complex Crustal Structure Beneath Western Turkey Revealed by 3D Seismic Full Waveform Inversion (FWI)

    NASA Astrophysics Data System (ADS)

    Cubuk-Sabuncu, Yesim; Taymaz, Tuncay; Fichtner, Andreas

    2016-04-01

    We present a 3D radially anisotropic velocity model of the crust and uppermost mantle structure beneath the Sea of Marmara and surroundings based on the full waveform inversion method. The intense seismic activity and crustal deformation are observed in the Northwest Turkey due to transition tectonics between the strike-slip North Anatolian Fault (NAF) and the extensional Aegean region. We have selected and simulated complete waveforms of 62 earthquakes (Mw > 4.0) occurred during 2007-2015, and recorded at (Δ < 10°) distances. Three component earthquake data is obtained from broadband seismic stations of Kandilli Observatory and Earthquake Research Center (KOERI, Turkey), Hellenic Unified Seismic Network (HUSN, Greece) and Earthquake Research Center of Turkey (AFAD-DAD). The spectral-element solver of the wave equation, SES3D algorithm, is used to simulate seismic wave propagation in 3D spherical coordinates (Fichtner, 2009). The Large Scale Seismic Inversion Framework (LASIF) workflow tool is also used to perform full seismic waveform inversion (Krischer et al., 2015). The initial 3D Earth model is implemented from the multi-scale seismic tomography study of Fichtner et al. (2013). Discrepancies between the observed and simulated synthetic waveforms are determined using the time-frequency misfits which allows a separation between phase and amplitude information (Fichtner et al., 2008). The conjugate gradient optimization method is used to iteratively update the initial Earth model when minimizing the misfit. The inversion is terminated after 19 iterations since no further advances are observed in updated models. Our analysis revealed shear wave velocity variations of the shallow and deeper crustal structure beneath western Turkey down to depths of ~35-40 km. Low shear wave velocity anomalies are observed in the upper and mid crustal depths beneath major fault zones located in the study region. Low velocity zones also tend to mark the outline of young volcanic

  17. 3D and 4D Seismic Imaging in the Oilfield; the state of the art

    NASA Astrophysics Data System (ADS)

    Strudley, A.

    2005-05-01

    Seismic imaging in the oilfield context has seen enormous changes over the last 20 years driven by a combination of improved subsurface illumination (2D to 3D), increased computational power and improved physical understanding. Today Kirchhoff Pre-stack migration (in time or depth) is the norm with anisotropic parameterisation and finite difference methods being increasingly employed. In the production context Time-Lapse (4D) Seismic is of growing importance as a tool for monitoring reservoir changes to facilitate increased productivity and recovery. In this paper we present an overview of state of the art technology in 3D and 4D seismic and look at future trends. Pre-stack Kirchhoff migration in time or depth is the imaging tool of choice for the majority of contemporary 3D datasets. Recent developments in 3D pre-stack imaging have been focussed around finite difference solutions to the acoustic wave equation, the so-called Wave Equation Migration methods (WEM). Application of finite difference solutions to imaging is certainly not new, however 3D pre-stack migration using these schemes is a relatively recent development driven by the need for imaging complex geologic structures such as sub salt, and facilitated by increased computational resources. Finally there are a class of imaging methods referred to as beam migration. These methods may be based on either the wave equation or rays, but all operate on a localised (in space and direction) part of the wavefield. These methods offer a bridge between the computational efficiency of Kirchhoff schemes and the improved image quality of WEM methods. Just as 3D seismic has had a radical impact on the quality of the static model of the reservoir, 4D seismic is having a dramatic impact on the dynamic model. Repeat shooting of seismic surveys after a period of production (typically one to several years) reveals changes in pressure and saturation through changes in the seismic response. The growth in interest in 4D seismic

  18. Vel-IO 3D: A tool for 3D velocity model construction, optimization and time-depth conversion in 3D geological modeling workflow

    NASA Astrophysics Data System (ADS)

    Maesano, Francesco E.; D'Ambrogi, Chiara

    2017-02-01

    We present Vel-IO 3D, a tool for 3D velocity model creation and time-depth conversion, as part of a workflow for 3D model building. The workflow addresses the management of large subsurface dataset, mainly seismic lines and well logs, and the construction of a 3D velocity model able to describe the variation of the velocity parameters related to strong facies and thickness variability and to high structural complexity. Although it is applicable in many geological contexts (e.g. foreland basins, large intermountain basins), it is particularly suitable in wide flat regions, where subsurface structures have no surface expression. The Vel-IO 3D tool is composed by three scripts, written in Python 2.7.11, that automate i) the 3D instantaneous velocity model building, ii) the velocity model optimization, iii) the time-depth conversion. They determine a 3D geological model that is consistent with the primary geological constraints (e.g. depth of the markers on wells). The proposed workflow and the Vel-IO 3D tool have been tested, during the EU funded Project GeoMol, by the construction of the 3D geological model of a flat region, 5700 km2 in area, located in the central part of the Po Plain. The final 3D model showed the efficiency of the workflow and Vel-IO 3D tool in the management of large amount of data both in time and depth domain. A 4 layer-cake velocity model has been applied to a several thousand (5000-13,000 m) thick succession, with 15 horizons from Triassic up to Pleistocene, complicated by a Mesozoic extensional tectonics and by buried thrusts related to Southern Alps and Northern Apennines.

  19. 3D Printing of Molecular Models

    ERIC Educational Resources Information Center

    Gardner, Adam; Olson, Arthur

    2016-01-01

    Physical molecular models have played a valuable role in our understanding of the invisible nano-scale world. We discuss 3D printing and its use in producing models of the molecules of life. Complex biomolecular models, produced from 3D printed parts, can demonstrate characteristics of molecular structure and function, such as viral self-assembly,…

  20. 3D Porosity Estimation of the Nankai Trough Sediments from Core-log-seismic Integration

    NASA Astrophysics Data System (ADS)

    Park, J. O.

    2015-12-01

    The Nankai Trough off southwest Japan is one of the best subduction-zone to study megathrust earthquake fault. Historic, great megathrust earthquakes with a recurrence interval of 100-200 yr have generated strong motion and large tsunamis along the Nankai Trough subduction zone. At the Nankai Trough margin, the Philippine Sea Plate (PSP) is being subducted beneath the Eurasian Plate to the northwest at a convergence rate ~4 cm/yr. The Shikoku Basin, the northern part of the PSP, is estimated to have opened between 25 and 15 Ma by backarc spreading of the Izu-Bonin arc. The >100-km-wide Nankai accretionary wedge, which has developed landward of the trench since the Miocene, mainly consists of offscraped and underplated materials from the trough-fill turbidites and the Shikoku Basin hemipelagic sediments. Particularly, physical properties of the incoming hemipelagic sediments may be critical for seismogenic behavior of the megathrust fault. We have carried out core-log-seismic integration (CLSI) to estimate 3D acoustic impedance and porosity for the incoming sediments in the Nankai Trough. For the CLSI, we used 3D seismic reflection data, P-wave velocity and density data obtained during IODP (Integrated Ocean Drilling Program) Expeditions 322 and 333. We computed acoustic impedance depth profiles for the IODP drilling sites from P-wave velocity and density data. We constructed seismic convolution models with the acoustic impedance profiles and a source wavelet which is extracted from the seismic data, adjusting the seismic models to observed seismic traces with inversion method. As a result, we obtained 3D acoustic impedance volume and then converted it to 3D porosity volume. In general, the 3D porosities show decrease with depth. We found a porosity anomaly zone with alteration of high and low porosities seaward of the trough axis. In this talk, we will show detailed 3D porosity of the incoming sediments, and present implications of the porosity anomaly zone for the

  1. ActiveSeismoPick3D - automatic first arrival determination for large active seismic arrays

    NASA Astrophysics Data System (ADS)

    Paffrath, Marcel; Küperkoch, Ludger; Wehling-Benatelli, Sebastian; Friederich, Wolfgang

    2016-04-01

    We developed a tool for automatic determination of first arrivals in active seismic data based on an approach, that utilises higher order statistics (HOS) and the Akaike information criterion (AIC), commonly used in seismology, but not in active seismics. Automatic picking is highly desirable in active seismics as the number of data provided by large seismic arrays rapidly exceeds of what an analyst can evaluate in a reasonable amount of time. To bring the functionality of automatic phase picking into the context of active data, the software package ActiveSeismoPick3D was developed in Python. It uses a modified algorithm for the determination of first arrivals which searches for the HOS maximum in unfiltered data. Additionally, it offers tools for manual quality control and postprocessing, e.g. various visualisation and repicking functionalities. For flexibility, the tool also includes methods for the preparation of geometry information of large seismic arrays and improved interfaces to the Fast Marching Tomography Package (FMTOMO), which can be used for the prediction of travel times and inversion for subsurface properties. Output files are generated in the VTK format, allowing the 3D visualization of e.g. the inversion results. As a test case, a data set consisting of 9216 traces from 64 shots was gathered, recorded at 144 receivers deployed in a regular 2D array of a size of 100 x 100 m. ActiveSeismoPick3D automatically checks the determined first arrivals by a dynamic signal to noise ratio threshold. From the data a 3D model of the subsurface was generated using the export functionality of the package and FMTOMO.

  2. Regional geothermal 3D modelling in Denmark

    NASA Astrophysics Data System (ADS)

    Poulsen, S. E.; Balling, N.; Bording, T. S.; Nielsen, S. B.

    2012-04-01

    In the pursuit of sustainable and low carbon emission energy sources, increased global attention has been given to the exploration and exploitation of geothermal resources within recent decades. In 2009 a national multi-disciplinary geothermal research project was established. As a significant part of this project, 3D temperature modelling is to be carried out, with special emphasis on temperatures of potential geothermal reservoirs in the Danish area. The Danish subsurface encompasses low enthalpy geothermal reservoirs of mainly Triassic and Jurassic age. Geothermal plants at Amager (Copenhagen) and Thisted (Northern Jutland) have the capacity of supplying the district heating network with up to 14 MW and 7 MW, respectively, by withdrawing warm pore water from the Gassum (Lower Jurassic/Upper Triassic) and Bunter (Lower Triassic) sandstone reservoirs, respectively. Explorative studies of the subsurface temperature regime typically are based on a combination of observations and modelling. In this study, the open-source groundwater modelling code MODFLOW is modified to simulate the subsurface temperature distribution in three dimensions by taking advantage of the mathematical similarity between saturated groundwater flow (Darcy flow) and heat conduction. A numerical model of the subsurface geology in Denmark is built and parameterized from lithological information derived from joint interpretation of seismic surveys and borehole information. Boundary conditions are constructed from knowledge about the heat flow from the Earth's interior and the shallow ground temperature. Matrix thermal conductivities have been estimated from analysis of high-resolution temperature logs measured in deep wells and porosity-depth relations are included using interpreted main lithologies. The model takes into account the dependency of temperature and pressure on thermal conductivity. Moreover, a transient model based correction of the paleoclimatic thermal disturbance caused by the

  3. Contribution of seismic processing to put up the scaffolding for the 3-dimensional study of deep sedimentary basins: the fundaments of trans-national 3D modelling in the project GeoMol

    NASA Astrophysics Data System (ADS)

    Capar, Laure

    2013-04-01

    Within the framework of the transnational project GeoMol geophysical and geological information on the entire Molasse Basin and on the Po Basin are gathered to build consistent cross-border 3D geological models based on borehole evidence and seismic data. Benefiting from important progress in seismic processing, these new models will provide some answers to various questions regarding the usage of subsurface resources, as there are geothermal energy, CO2 and gas storage, oil and gas production, and support decisions-making to national and local administrations as well as to industries. More than 28 000 km of 2D seismic lines are compiled reprocessed and harmonized. This work faces various problems like the vertical drop of more than 700 meters between West and East of the Molasse Basin and to al lesser extent in the Po Plain, the heterogeneities of the substratum, the large disparities between the period and parameters of seismic acquisition, and depending of their availability, the use of two types of seismic data, raw and processed seismic data. The main challenge is to harmonize all lines at the same reference level, amplitude and step of signal processing from France to Austria, spanning more than 1000 km, to avoid misfits at crossing points between seismic lines and artifacts at the country borders, facilitating the interpretation of the various geological layers in the Molasse Basin and Po Basin. A generalized stratigraphic column for the two basins is set up, representing all geological layers relevant to subsurface usage. This stratigraphy constitutes the harmonized framework for seismic reprocessing. In general, processed seismic data is available on paper at stack stage and the mandatory information to take these seismic lines to the final stage of processing, the migration step, are datum plane and replacement velocity. However several datum planes and replacement velocities were used during previous processing projects. Our processing sequence is to

  4. Imaging of 3-D seismic velocity structure of Southern Sumatra region using double difference tomographic method

    NASA Astrophysics Data System (ADS)

    Lestari, Titik; Nugraha, Andri Dian

    2015-04-01

    Southern Sumatra region has a high level of seismicity due to the influence of the subduction system, Sumatra fault, Mentawai fault and stretching zone activities. The seismic activities of Southern Sumatra region are recorded by Meteorological Climatological and Geophysical Agency (MCGA's) Seismograph network. In this study, we used earthquake data catalog compiled by MCGA for 3013 events from 10 seismic stations around Southern Sumatra region for time periods of April 2009 - April 2014 in order to invert for the 3-D seismic velocities structure (Vp, Vs, and Vp/Vs ratio). We applied double-difference seismic tomography method (tomoDD) to determine Vp, Vs and Vp/Vs ratio with hypocenter adjustment. For the inversion procedure, we started from the initial 1-D seismic velocity model of AK135 and constant Vp/Vs of 1.73. The synthetic travel time from source to receiver was calculated using ray pseudo-bending technique, while the main tomographic inversion was applied using LSQR method. The resolution model was evaluated using checkerboard test and Derivative Weigh Sum (DWS). Our preliminary results show low Vp and Vs anomalies region along Bukit Barisan which is may be associated with weak zone of Sumatran fault and migration of partial melted material. Low velocity anomalies at 30-50 km depth in the fore arc region may indicated the hydrous material circulation because the slab dehydration. We detected low seismic seismicity in the fore arc region that may be indicated as seismic gap. It is coincides contact zone of high and low velocity anomalies. And two large earthquakes (Jambi and Mentawai) also occurred at the contact of contrast velocity.

  5. Imaging of 3-D seismic velocity structure of Southern Sumatra region using double difference tomographic method

    SciTech Connect

    Lestari, Titik; Nugraha, Andri Dian

    2015-04-24

    Southern Sumatra region has a high level of seismicity due to the influence of the subduction system, Sumatra fault, Mentawai fault and stretching zone activities. The seismic activities of Southern Sumatra region are recorded by Meteorological Climatological and Geophysical Agency (MCGA’s) Seismograph network. In this study, we used earthquake data catalog compiled by MCGA for 3013 events from 10 seismic stations around Southern Sumatra region for time periods of April 2009 – April 2014 in order to invert for the 3-D seismic velocities structure (Vp, Vs, and Vp/Vs ratio). We applied double-difference seismic tomography method (tomoDD) to determine Vp, Vs and Vp/Vs ratio with hypocenter adjustment. For the inversion procedure, we started from the initial 1-D seismic velocity model of AK135 and constant Vp/Vs of 1.73. The synthetic travel time from source to receiver was calculated using ray pseudo-bending technique, while the main tomographic inversion was applied using LSQR method. The resolution model was evaluated using checkerboard test and Derivative Weigh Sum (DWS). Our preliminary results show low Vp and Vs anomalies region along Bukit Barisan which is may be associated with weak zone of Sumatran fault and migration of partial melted material. Low velocity anomalies at 30-50 km depth in the fore arc region may indicated the hydrous material circulation because the slab dehydration. We detected low seismic seismicity in the fore arc region that may be indicated as seismic gap. It is coincides contact zone of high and low velocity anomalies. And two large earthquakes (Jambi and Mentawai) also occurred at the contact of contrast velocity.

  6. 3D Microperfusion Model of ADPKD

    DTIC Science & Technology

    2015-10-01

    Stratasys 3D printer . PDMS was cast in the negative molds in order to create permanent biocompatible plastic masters (SmoothCast 310). All goals of task...1 AWARD NUMBER: W81XWH-14-1-0304 TITLE: 3D Microperfusion Model of ADPKD PRINCIPAL INVESTIGATOR: David L. Kaplan CONTRACTING ORGANIZATION...ADDRESS. 1. REPORT DATE October 2015 2. REPORT TYPE Annual Report 3. DATES COVERED 15 Sep 2014 - 14 Sep 2015 4. TITLE AND SUBTITLE 3D

  7. Fluid Substitution Modeling to Determine Sensitivity of 3D Vertical Seismic Profile Data to Injected CO­2­ at an active Carbon Capture, Utilization and Storage Project, Farnsworth field, TX.

    NASA Astrophysics Data System (ADS)

    Haar, K. K.; Balch, R. S.

    2015-12-01

    The Southwest Regional Partnership on Carbon Sequestration monitors a CO2 capture, utilization and storage project at Farnsworth field, TX. The reservoir interval is a Morrowan age fluvial sand deposited in an incised valley. The sands are between 10 to 25m thick and located about 2800m below the surface. Primary oil recovery began in 1958 and by the late 1960's secondary recovery through waterflooding was underway. In 2009, Chaparral Energy began tertiary recovery using 100% anthropogenic CO2 sourced from an ethanol and a fertilizer plant. This constitutes carbon sequestration and fulfills the DOE's initiative to determine the best approach to permanent carbon storage. One purpose of the study is to understand CO­2 migration from injection wells. CO2­ plume spatial distribution for this project is analyzed with the use of time-lapse 3D vertical seismic profiles centered on CO2 injection wells. They monitor raypaths traveling in a single direction compared to surface seismic surveys with raypaths traveling in both directions. 3D VSP surveys can image up to 1.5km away from the well of interest, exceeding regulatory requirements for maximum plume extent by a factor of two. To optimize the timing of repeat VSP acquisition, the sensitivity of the 3D VSP surveys to CO2 injection was analyzed to determine at what injection volumes a seismic response to the injected CO­2 will be observable. Static geologic models were generated for pre-CO2 and post-CO2 reservoir states through construction of fine scale seismic based geologic models, which were then history matched via flow simulations. These generated static states of the model, where CO2­ replaces oil and brine in pore spaces, allow for generation of impedance volumes which when convolved with a representative wavelet generate synthetic seismic volumes used in the sensitivity analysis. Funding for the project is provided by DOE's National Energy Technology Laboratory (NETL) under Award No. DE-FC26-05NT42591.

  8. BEAMS3D Neutral Beam Injection Model

    SciTech Connect

    Lazerson, Samuel

    2014-04-14

    With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

  9. Modeling cellular processes in 3D.

    PubMed

    Mogilner, Alex; Odde, David

    2011-12-01

    Recent advances in photonic imaging and fluorescent protein technology offer unprecedented views of molecular space-time dynamics in living cells. At the same time, advances in computing hardware and software enable modeling of ever more complex systems, from global climate to cell division. As modeling and experiment become more closely integrated we must address the issue of modeling cellular processes in 3D. Here, we highlight recent advances related to 3D modeling in cell biology. While some processes require full 3D analysis, we suggest that others are more naturally described in 2D or 1D. Keeping the dimensionality as low as possible reduces computational time and makes models more intuitively comprehensible; however, the ability to test full 3D models will build greater confidence in models generally and remains an important emerging area of cell biological modeling.

  10. Definition of subsurface stratigraphy, structure and rock properties from 3-D seismic data

    NASA Astrophysics Data System (ADS)

    Hart, Bruce S.

    1999-10-01

    This paper summarizes how three-dimensional (3-D) seismic technology is being used, primarily in the petroleum industry, to define subsurface structure, stratigraphy and rock properties. A 3-D seismic data volume: (a) provides a more accurate image of the subsurface than can be obtained with 2-D seismic methods; (b) is continuous, and so has a much greater spatial sampling than is obtained with 2-D seismic or other subsurface data (e.g., wells); and (c) can be viewed and interpreted interactively from a variety of perspectives, thus enhancing the interpreter's ability to generate an accurate description of subsurface features of interest. Seismic interpretation was once the almost exclusive realm of geophysicists, however, most 3-D seismic interpretation today is conducted by multidisciplinary teams that integrate geophysical, geological, petrophysical and engineering data and concepts into the 3-D seismic interpretation. These factors, plus proper survey design, help to increase the chances of success of a 3-D seismic interpretation project. Although there are cases where the technology is not appropriate or cannot be applied (for economic reasons or otherwise), the general success of 3-D seismic has led it to become a mainstay of the petroleum industry. The approach and technology, first developed in that industry, have potential applications in other applied and fundamental earth science disciplines, including mining, environmental geology, structural geology and stratigraphy.

  11. RHOCUBE: 3D density distributions modeling code

    NASA Astrophysics Data System (ADS)

    Nikutta, Robert; Agliozzo, Claudia

    2016-11-01

    RHOCUBE models 3D density distributions on a discrete Cartesian grid and their integrated 2D maps. It can be used for a range of applications, including modeling the electron number density in LBV shells and computing the emission measure. The RHOCUBE Python package provides several 3D density distributions, including a powerlaw shell, truncated Gaussian shell, constant-density torus, dual cones, and spiralling helical tubes, and can accept additional distributions. RHOCUBE provides convenient methods for shifts and rotations in 3D, and if necessary, an arbitrary number of density distributions can be combined into the same model cube and the integration ∫ dz performed through the joint density field.

  12. Characterization of landslide geometry using 3D seismic refraction traveltime tomography

    NASA Astrophysics Data System (ADS)

    Samyn, K.; Travelletti, J.; Bitri, A.; Grandjean, G.; Malet, J. P.

    2012-04-01

    The geometry of the bedrock, internal layers and shear surfaces/bands controls the deformation pattern and the mechanisms of landslides. A challenge to progress in the forecast of landslide acceleration in terms of early-warning is therefore to characterize the 3D geometry of the unstable mass at a high level of spatial resolution, both in the horizontal and vertical directions, by integrating information from different surveying techniques. For such characterization, seismic investigations are potentially of a great interest. In the case of complex structures, the measure and the processing of seismic data need to be performed in 3D. The objective of this work is to present the implementation of a 3D seismic refraction traveltime tomography technique based on an existing 2D Simultaneous Iterative Reconstruction Technique (SIRT). First the processing algorithm is detailed and its performance is discussed, and second an application to the La Valette complex landslide is presented. Inversion of first-arrival traveltimes produces a 3D tomogram that underlines the presence of many areas characterized by low P-wave velocity of 500-1800 m.s-1. These low P-wave velocity structures result from the presence of reworked blocks, surficial cracks and in-depth fracture zones. These structures seem to extend to around 25 m in depth over a 80 x 130 m area. Based on borehole geotechnical data and previous geophysical investigations, an interface corresponding to an internal slip surface can be suspected near the isovalue of 1200 m.s-1 at a depth of -10 to -15 m. The stable substratum is characterized by higher values of P-wave velocity of 1800-3000 m.s-1. The features identified in the 3D tomogram allow to better (1) delineate the boundary between the landslide and the surrounding stable slopes, and (2) understand the morphological structures within the landslide at a hectometric scale. The integration of the 3D seismic tomography interpretation to previous geophysical

  13. A Hybrid 3D Indoor Space Model

    NASA Astrophysics Data System (ADS)

    Jamali, Ali; Rahman, Alias Abdul; Boguslawski, Pawel

    2016-10-01

    GIS integrates spatial information and spatial analysis. An important example of such integration is for emergency response which requires route planning inside and outside of a building. Route planning requires detailed information related to indoor and outdoor environment. Indoor navigation network models including Geometric Network Model (GNM), Navigable Space Model, sub-division model and regular-grid model lack indoor data sources and abstraction methods. In this paper, a hybrid indoor space model is proposed. In the proposed method, 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. This research proposes a method of indoor space modeling for the buildings which do not have proper 2D/3D geometrical models or they lack semantic or topological information. The proposed hybrid model consists of topological, geometrical and semantical space.

  14. NUBEAM developments and 3d halo modeling

    NASA Astrophysics Data System (ADS)

    Gorelenkova, M. V.; Medley, S. S.; Kaye, S. M.

    2012-10-01

    Recent developments related to the 3D halo model in NUBEAM code are described. To have a reliable halo neutral source for diagnostic simulation, the TRANSP/NUBEAM code has been enhanced with full implementation of ADAS atomic physic ground state and excited state data for hydrogenic beams and mixed species plasma targets. The ADAS codes and database provide the density and temperature dependence of the atomic data, and the collective nature of the state excitation process. To be able to populate 3D halo output with sufficient statistical resolution, the capability to control the statistics of fast ion CX modeling and for thermal halo launch has been added to NUBEAM. The 3D halo neutral model is based on modification and extension of the ``beam in box'' aligned 3d Cartesian grid that includes the neutral beam itself, 3D fast neutral densities due to CX of partially slowed down fast ions in the beam halo region, 3D thermal neutral densities due to CX deposition and fast neutral recapture source. More details on the 3D halo simulation design will be presented.

  15. Seismic Response of 3D Steel Buildings considering the Effect of PR Connections and Gravity Frames

    PubMed Central

    Haldar, Achintya; López-Barraza, Arturo; Rivera-Salas, J. Luz

    2014-01-01

    The nonlinear seismic responses of 3D steel buildings with perimeter moment resisting frames (PMRF) and interior gravity frames (IGF) are studied explicitly considering the contribution of the IGF. The effect on the structural response of the stiffness of the beam-to-column connections of the IGF, which is usually neglected, is also studied. It is commonly believed that the flexibility of shear connections is negligible and that 2D models can be used to properly represent 3D real structures. The results of the study indicate, however, that the moments developed on columns of IGF can be considerable and that modeling buildings as plane frames may result in very conservative designs. The contribution of IGF to the lateral structural resistance may be significant. The contribution increases when their connections are assumed to be partially restrained (PR). The incremented participation of IGF when the stiffness of their connections is considered helps to counteract the no conservative effect that results in practice when lateral seismic loads are not considered in IGF while designing steel buildings with PMRF. Thus, if the structural system under consideration is used, the three-dimensional model should be used in seismic analysis and the IGF and the stiffness of their connections should be considered as part of the lateral resistance system. PMID:24995357

  16. Seismic response of 3D steel buildings considering the effect of PR connections and gravity frames.

    PubMed

    Reyes-Salazar, Alfredo; Bojórquez, Edén; Haldar, Achintya; López-Barraza, Arturo; Rivera-Salas, J Luz

    2014-01-01

    The nonlinear seismic responses of 3D steel buildings with perimeter moment resisting frames (PMRF) and interior gravity frames (IGF) are studied explicitly considering the contribution of the IGF. The effect on the structural response of the stiffness of the beam-to-column connections of the IGF, which is usually neglected, is also studied. It is commonly believed that the flexibility of shear connections is negligible and that 2D models can be used to properly represent 3D real structures. The results of the study indicate, however, that the moments developed on columns of IGF can be considerable and that modeling buildings as plane frames may result in very conservative designs. The contribution of IGF to the lateral structural resistance may be significant. The contribution increases when their connections are assumed to be partially restrained (PR). The incremented participation of IGF when the stiffness of their connections is considered helps to counteract the no conservative effect that results in practice when lateral seismic loads are not considered in IGF while designing steel buildings with PMRF. Thus, if the structural system under consideration is used, the three-dimensional model should be used in seismic analysis and the IGF and the stiffness of their connections should be considered as part of the lateral resistance system.

  17. Thrust fault growth within accretionary wedges: New Insights from 3D seismic reflection data

    NASA Astrophysics Data System (ADS)

    Orme, H.; Bell, R. E.; Jackson, C. A. L.

    2015-12-01

    The shallow parts of subduction megathrust faults are typically thought to be aseismic and incapable of propagating seismic rupture. The 2011 Tohoku-Oki earthquake, however, ruptured all the way to the trench, proving that in some locations rupture can propagate through the accretionary wedge. An improved understanding of the structural character and physical properties of accretionary wedges is therefore crucial to begin to assess why such anomalously shallow seismic rupture occurs. Despite its importance, we know surprisingly little regarding the 3D geometry and kinematics of thrust network development in accretionary prisms, largely due to a lack of 3D seismic reflection data providing high-resolution, 3D images of entire networks. Thus our current understanding is largely underpinned by observations from analogue and numerical modelling, with limited observational data from natural examples. In this contribution we use PSDM, 3D seismic reflection data from the Nankai margin (3D Muroto dataset, available from the UTIG Academic Seismic Portal, Marine Geoscience Data System) to examine how imbricate thrust fault networks evolve during accretionary wedge growth. Previous studies have reported en-echelon thrust fault geometries from the NW part of the dataset, and have related this complex structure to seamount subduction. We unravel the evolution of faults within the protothrust and imbricate thrust zones by interpreting multiple horizons across faults and measuring fault displacement and fold amplitude along-strike; by doing this, we are able to investigate the three dimensional accrual of strain. We document a number of local displacement minima along-strike of faults, suggesting that, the protothrust and imbricate thrusts developed from the linkage of smaller, previously isolated fault segments. We also demonstrate that the majority of faults grew upward from the décollement, although there is some evidence for downward fault propagation. Our observations

  18. High-resolution imaging of crustal melts using 3D full-waveform seismic inversion

    NASA Astrophysics Data System (ADS)

    Warner, M.; Morgan, J. V.

    2013-12-01

    A newly practical seismic imaging technique, 3D full-waveform inversion (FWI), now has the ability to image zones of melt and melt pathways throughout the crust with a better resolution than any other geophysical method. 3D FWI has recently changed practice within the petroleum industry where it is used to obtain high-resolution high-fidelity models of physical properties in the sub-surface that are both interpreted directly and used to improve the migration of deeper reflections. This technology has been spectacularly successful in improving the imaging of reservoirs beneath shallow heterogeneities produced by, for example, gas clouds, buried fluvial channels, carbonate reefs and salt bodies. During FWI, the sub-surface model is recovered principally by using the low-frequency transmitted, refracted portion of the wavefield which is most sensitive to the macro-velocity structure. In the petroleum industry, these inversions are now routinely performed using long-offset surface-streamer and ocean-bottom data to maximum source-receiver offsets of about 15 km, leading to a maximum penetration depth of around 5 km. Using longer offsets, it is possible to extend this technology to image deeper crustal targets. Localised zones of partial melt produce large changes in p-wave and s-wave properties that are restricted in their spatial extent, and that therefore form ideal targets for 3D FWI. We have performed a suite of tests to explore the use of 3D FWI in imaging melt distribution beneath the active volcano of Montserrat. We built a model of the subsurface using a 3D travel-time tomographic model obtained from the SEA CALIPSO experiment. We added two magma chambers in accordance with a model obtained using surface-elevation changes and geochemical data. We used a wide-angle, wide-azimuth acquisition geometry to generate a fully-elastic synthetic seismic dataset, added noise, and inverted the windowed transmitted arrivals only. We used an elastic code for the forward

  19. Training toward Advanced 3D Seismic Methods for CO2 Monitoring, Verification, and Accounting

    SciTech Connect

    Christopher Liner

    2012-05-31

    The objective of our work is graduate and undergraduate student training related to improved 3D seismic technology that addresses key challenges related to monitoring movement and containment of CO{sub 2}, specifically better quantification and sensitivity for mapping of caprock integrity, fractures, and other potential leakage pathways. We utilize data and results developed through previous DOE-funded CO{sub 2} characterization project (DE-FG26-06NT42734) at the Dickman Field of Ness County, KS. Dickman is a type locality for the geology that will be encountered for CO{sub 2} sequestration projects from northern Oklahoma across the U.S. midcontinent to Indiana and Illinois. Since its discovery in 1962, the Dickman Field has produced about 1.7 million barrels of oil from porous Mississippian carbonates with a small structural closure at about 4400 ft drilling depth. Project data includes 3.3 square miles of 3D seismic data, 142 wells, with log, some core, and oil/water production data available. Only two wells penetrate the deep saline aquifer. In a previous DOE-funded project, geological and seismic data were integrated to create a geological property model and a flow simulation grid. We believe that sequestration of CO{sub 2} will largely occur in areas of relatively flat geology and simple near surface, similar to Dickman. The challenge is not complex geology, but development of improved, lower-cost methods for detecting natural fractures and subtle faults. Our project used numerical simulation to test methods of gathering multicomponent, full azimuth data ideal for this purpose. Our specific objectives were to apply advanced seismic methods to aide in quantifying reservoir properties and lateral continuity of CO{sub 2} sequestration targets. The purpose of the current project is graduate and undergraduate student training related to improved 3D seismic technology that addresses key challenges related to monitoring movement and containment of CO{sub 2

  20. 3D Numerical Simulation on the Sloshing Waves Excited by the Seismic Shacking

    NASA Astrophysics Data System (ADS)

    Zhang, Lin; Wu, Tso-Ren

    2016-04-01

    In the event of 2015 Nepal earthquake, a video clip broadcasted worldwide showed a violent water spilling in a hotel swimming pool. This sloshing phenomenon indicates a potential water loss in the sensitive facilities, e.g. the spent fuel pools in nuclear power plant, has to be taken into account carefully under the consideration of seismic-induced ground acceleration. In the previous studies, the simulation of sloshing mainly focused on the pressure force on the structure by using a simplified Spring-Mass Method developed in the field of solid mechanics. However, restricted by the assumptions of plane water surface and limited wave height, significant error will be made in evaluating the amount of water loss in the tank. In this paper, the computational fluid dynamical model, Splash3D, was adopted for studying the sloshing problem accurately. Splash3D solved 3D Navier-Stokes Equation directly with Large-Eddy Simulation (LES) turbulent closure. The Volume-of-fluid (VOF) method with piecewise linear interface calculation (PLIC) was used to track the complex breaking water surface. The time series acceleration of a design seismic was loaded to excite the water. With few restrictions from the assumptions, the accuracy of the simulation results were improved dramatically. A series model validations were conducted by compared to a 2D theoretical solution, and a 3D experimental data. Good comparisons can be seen. After the validation, we performed the simulation for considering a sloshing case in a rectangular water tank with a dimension of 12 m long, 8 m wide, 8 m deep, which contained water with 7 m in depth. The seismic movement was imported by considering time-series acceleration in three dimensions, which were about 0.5 g to 1.2 g in the horizontal directions, and 0.3 g to 1 g in the vertical direction. We focused the discussions on the kinematics of the water surface, wave breaking, velocity field, pressure field, water force on the side walls, and, most

  1. 3D Seismic Flexure Analysis for Subsurface Fault Detection and Fracture Characterization

    NASA Astrophysics Data System (ADS)

    Di, Haibin; Gao, Dengliang

    2017-03-01

    Seismic flexure is a new geometric attribute with the potential of delineating subtle faults and fractures from three-dimensional (3D) seismic surveys, especially those overlooked by the popular discontinuity and curvature attributes. Although the concept of flexure and its related algorithms have been published in the literature, the attribute has not been sufficiently applied to subsurface fault detection and fracture characterization. This paper provides a comprehensive study of the flexure attribute, including its definition, computation, as well as geologic implications for evaluating the fundamental fracture properties that are essential to fracture characterization and network modeling in the subsurface, through applications to the fractured reservoir at Teapot Dome, Wyoming (USA). Specifically, flexure measures the third-order variation of the geometry of a seismic reflector and is dependent on the measuring direction in 3D space; among all possible directions, flexure is considered most useful when extracted perpendicular to the orientation of dominant deformation; and flexure offers new insights into qualitative/quantitative fracture characterization, with its magnitude indicating the intensity of faulting and fracturing, its azimuth defining the orientation of most-likely fracture trends, and its sign differentiating the sense of displacement of faults and fractures.

  2. 3D Seismic Flexure Analysis for Subsurface Fault Detection and Fracture Characterization

    NASA Astrophysics Data System (ADS)

    Di, Haibin; Gao, Dengliang

    2016-10-01

    Seismic flexure is a new geometric attribute with the potential of delineating subtle faults and fractures from three-dimensional (3D) seismic surveys, especially those overlooked by the popular discontinuity and curvature attributes. Although the concept of flexure and its related algorithms have been published in the literature, the attribute has not been sufficiently applied to subsurface fault detection and fracture characterization. This paper provides a comprehensive study of the flexure attribute, including its definition, computation, as well as geologic implications for evaluating the fundamental fracture properties that are essential to fracture characterization and network modeling in the subsurface, through applications to the fractured reservoir at Teapot Dome, Wyoming (USA). Specifically, flexure measures the third-order variation of the geometry of a seismic reflector and is dependent on the measuring direction in 3D space; among all possible directions, flexure is considered most useful when extracted perpendicular to the orientation of dominant deformation; and flexure offers new insights into qualitative/quantitative fracture characterization, with its magnitude indicating the intensity of faulting and fracturing, its azimuth defining the orientation of most-likely fracture trends, and its sign differentiating the sense of displacement of faults and fractures.

  3. Simulation of 3D Global Wave Propagation Through Geodynamic Models

    NASA Astrophysics Data System (ADS)

    Schuberth, B.; Piazzoni, A.; Bunge, H.; Igel, H.; Steinle-Neumann, G.

    2005-12-01

    This project aims at a better understanding of the forward problem of global 3D wave propagation. We use the spectral element program "SPECFEM3D" (Komatitsch and Tromp, 2002a,b) with varying input models of seismic velocities derived from mantle convection simulations (Bunge et al., 2002). The purpose of this approach is to obtain seismic velocity models independently from seismological studies. In this way one can test the effects of varying parameters of the mantle convection models on the seismic wave field. In order to obtain the seismic velocities from the temperature field of the geodynamical simulations we follow a mineral physics approach. Assuming a certain mantle composition (e.g. pyrolite with CMASF composition) we compute the stable phases for each depth (i.e. pressure) and temperature by system Gibbs free energy minimization. Elastic moduli and density are calculated from the equations of state of the stable mineral phases. For this we use a mineral physics database derived from calorimetric experiments (enthalphy and entropy of formation, heat capacity) and EOS parameters.

  4. 3D Modeling Engine Representation Summary Report

    SciTech Connect

    Steven Prescott; Ramprasad Sampath; Curtis Smith; Timothy Yang

    2014-09-01

    Computers have been used for 3D modeling and simulation, but only recently have computational resources been able to give realistic results in a reasonable time frame for large complex models. This summary report addressed the methods, techniques, and resources used to develop a 3D modeling engine to represent risk analysis simulation for advanced small modular reactor structures and components. The simulations done for this evaluation were focused on external events, specifically tsunami floods, for a hypothetical nuclear power facility on a coastline.

  5. 3-D shear wave velocity model of Mexico and South US: bridging seismic networks with ambient noise cross-correlations (C1) and correlation of coda of correlations (C3)

    NASA Astrophysics Data System (ADS)

    Spica, Zack; Perton, Mathieu; Calò, Marco; Legrand, Denis; Córdoba-Montiel, Francisco; Iglesias, Arturo

    2016-09-01

    This work presents an innovative strategy to enhance the resolution of surface wave tomography obtained from ambient noise cross-correlation (C1) by bridging asynchronous seismic networks through the correlation of coda of correlations (C3). Rayleigh wave group dispersion curves show consistent results between synchronous and asynchronous stations. Rayleigh wave group traveltimes are inverted to construct velocity-period maps with unprecedented resolution for a region covering Mexico and the southern United States. The resulting period maps are then used to regionalize dispersion curves in order to obtain local 1-D shear velocity models (VS) of the crust and uppermost mantle in every cell of a grid of 0.4°. The 1-D structures are obtained by iteratively adding layers until reaching a given misfit, and a global tomography model is considered as an input for depths below 150 km. Finally, a high-resolution 3-D VS model is obtained from these inversions. The major structures observed in the 3-D model are in agreement with the tectonic-geodynamic features and with previous regional and local studies. It also offers new insights to understand the present and past tectonic evolution of the region.

  6. BEAMS3D Neutral Beam Injection Model

    NASA Astrophysics Data System (ADS)

    McMillan, Matthew; Lazerson, Samuel A.

    2014-09-01

    With the advent of applied 3D fields in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous slowing down, and pitch angle scattering are modeled with the ADAS atomic physics database. Elementary benchmark calculations are presented to verify the collisionless particle orbits, NBI model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields. Notice: this manuscript has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.

  7. Using 3D visualization and seismic attributes to improve structural and stratigraphic resolution of reservoirs

    SciTech Connect

    Kerr, J. ); Jones, G.L. )

    1996-01-01

    Recent advances in hardware and software have given the interpreter and engineer new ways to view 3D seismic data and well bore information. Recent papers have also highlighted the use of various statistics and seismic attributes. By combining new 3D rendering technologies with recent trends in seismic analysis, the interpreter can improve the structural and stratigraphic resolution of hydrocarbon reservoirs. This paper gives several examples using 3D visualization to better define both the structural and stratigraphic aspects of several different structural types from around the world. Statistics, 3D visualization techniques and rapid animation are used to show complex faulting and detailed channel systems. These systems would be difficult to map using either 2D or 3D data with conventional interpretation techniques.

  8. Using 3D visualization and seismic attributes to improve structural and stratigraphic resolution of reservoirs

    SciTech Connect

    Kerr, J.; Jones, G.L.

    1996-12-31

    Recent advances in hardware and software have given the interpreter and engineer new ways to view 3D seismic data and well bore information. Recent papers have also highlighted the use of various statistics and seismic attributes. By combining new 3D rendering technologies with recent trends in seismic analysis, the interpreter can improve the structural and stratigraphic resolution of hydrocarbon reservoirs. This paper gives several examples using 3D visualization to better define both the structural and stratigraphic aspects of several different structural types from around the world. Statistics, 3D visualization techniques and rapid animation are used to show complex faulting and detailed channel systems. These systems would be difficult to map using either 2D or 3D data with conventional interpretation techniques.

  9. Complex patterns of faulting revealed by 3D seismic data at the West Galicia rifted margin

    NASA Astrophysics Data System (ADS)

    Reston, Timothy; Cresswell, Derren; Sawyer, Dale; Ranero, Cesar; Shillington, Donna; Morgan, Julia; Lymer, Gael

    2015-04-01

    The west Galicia margin is characterised by crust thinning to less than 3 km, well-defined fault blocks, which overlie a bright reflection (the S reflector) generally interpreted as a tectonic Moho. The margin exhibits neither voluminous magmatism nor thick sediment piles to obscure the structures and the amount of extension. As such is represents an ideal location to study the process of continental breakup both through seismic imaging and potentially through drilling. Prestack depth migration of existing 2D profiles has strongly supported the interpretation of the S reflector as both a detachment and as the crust-mantle boundary; wide-angle seismic has also shown that the mantle beneath S is serpentinised. Despite the quality of the existing 2D seismic images, a number of competing models have been advanced to explain the formation of this margin, including sequential faulting, polyphase faulting, multiple detachments and the gravitational collapse of the margin over exhumed mantle. As these models, all developed for the Galicia margin, have been subsequently applied to other margins, distinguishing between them has implications not only for the structure of the Galicia margin but for the process of rifting through to breakup more generally. To address these issues in summer of 2013 we collected a 3D combined seismic reflection and wide-angle dataset over this margin. Here we present some of the results of ongoing processing of the 3D volume, focussing on the internal structure of some of the fault blocks that overlies the S detachment. 2D processing of the data shows a relatively simple series of tilted fault block, bound by west-dipping faults that detach downwards onto the bright S reflector. However, inspection of the 3D volume produced by 3D pre-stack time migration reveals that the fault blocks contain a complex set of sedimentary packages, with strata tilted to the east, west, north and south, each package bound by faults. Furthermore, the top of crustal

  10. Effect of Damping and Yielding on the Seismic Response of 3D Steel Buildings with PMRF

    PubMed Central

    Haldar, Achintya; Rodelo-López, Ramon Eduardo; Bojórquez, Eden

    2014-01-01

    The effect of viscous damping and yielding, on the reduction of the seismic responses of steel buildings modeled as three-dimensional (3D) complex multidegree of freedom (MDOF) systems, is studied. The reduction produced by damping may be larger or smaller than that of yielding. This reduction can significantly vary from one structural idealization to another and is smaller for global than for local response parameters, which in turn depends on the particular local response parameter. The uncertainty in the estimation is significantly larger for local response parameter and decreases as damping increases. The results show the limitations of the commonly used static equivalent lateral force procedure where local and global response parameters are reduced in the same proportion. It is concluded that estimating the effect of damping and yielding on the seismic response of steel buildings by using simplified models may be a very crude approximation. Moreover, the effect of yielding should be explicitly calculated by using complex 3D MDOF models instead of estimating it in terms of equivalent viscous damping. The findings of this paper are for the particular models used in the study. Much more research is needed to reach more general conclusions. PMID:25097892

  11. Effect of damping and yielding on the seismic response of 3D steel buildings with PMRF.

    PubMed

    Reyes-Salazar, Alfredo; Haldar, Achintya; Rodelo-López, Ramon Eduardo; Bojórquez, Eden

    2014-01-01

    The effect of viscous damping and yielding, on the reduction of the seismic responses of steel buildings modeled as three-dimensional (3D) complex multidegree of freedom (MDOF) systems, is studied. The reduction produced by damping may be larger or smaller than that of yielding. This reduction can significantly vary from one structural idealization to another and is smaller for global than for local response parameters, which in turn depends on the particular local response parameter. The uncertainty in the estimation is significantly larger for local response parameter and decreases as damping increases. The results show the limitations of the commonly used static equivalent lateral force procedure where local and global response parameters are reduced in the same proportion. It is concluded that estimating the effect of damping and yielding on the seismic response of steel buildings by using simplified models may be a very crude approximation. Moreover, the effect of yielding should be explicitly calculated by using complex 3D MDOF models instead of estimating it in terms of equivalent viscous damping. The findings of this paper are for the particular models used in the study. Much more research is needed to reach more general conclusions.

  12. 3D modeling of geological anomalies based on segmentation of multiattribute fusion

    NASA Astrophysics Data System (ADS)

    Liu, Zhi-Ning; Song, Cheng-Yun; Li, Zhi-Yong; Cai, Han-Peng; Yao, Xing-Miao; Hu, Guang-Min

    2016-09-01

    3D modeling of geological bodies based on 3D seismic data is used to define the shape and volume of the bodies, which then can be directly applied to reservoir prediction, reserve estimation, and exploration. However, multiattributes are not effectively used in 3D modeling. To solve this problem, we propose a novel method for building of 3D model of geological anomalies based on the segmentation of multiattribute fusion. First, we divide the seismic attributes into edge- and region-based seismic attributes. Then, the segmentation model incorporating the edge- and region-based models is constructed within the levelset-based framework. Finally, the marching cubes algorithm is adopted to extract the zero level set based on the segmentation results and build the 3D model of the geological anomaly. Combining the edge-and region-based attributes to build the segmentation model, we satisfy the independence requirement and avoid the problem of insufficient data of single seismic attribute in capturing the boundaries of geological anomalies. We apply the proposed method to seismic data from the Sichuan Basin in southwestern China and obtain 3D models of caves and channels. Compared with 3D models obtained based on single seismic attributes, the results are better agreement with reality.

  13. Structure of the ophiolite-hosted Outokumpu Cu-Co-Zn-Ni-Ag-Au sulfide ore district revealed by combined 3D modelling and 2D high-resolution seismic reflection data

    NASA Astrophysics Data System (ADS)

    Saalmann, Kerstin; Laine, Eevaliisa

    2015-04-01

    The Outokumpu district within the North Karelia Schist Belt in eastern Finland hosts Cu-Co-Zn-Ni-Ag-Au sulfide deposits which are associated with Palaeoproterozoic ophiolitic metaperidotites that were tectonically interleaved with allochthonous metaturbidites. Extensive metasomatism of the peridotites produced a rim of quartz-carbonate-calc-silicate rocks, grouped as the Outokumpu assemblage (OKA). A tectonic history comprising various phases of folding and shearing followed by several faulting events dismembered the metaperidotites so that ore bodies cannot be easily followed along strike. Future exploration has to expand the search into deeper areas and consequently requires better knowledge of the subsurface geology. In order to unravel the complex structure 3D geologic models of different scales have been built using a variety of information: geological maps, aeromagnetic and gravity maps, digital terrain models, mine cross sections, drill core logs combined with observations from underground mine galleries, structural measurements, and data from seismic survey lines. The latter have been used to detect upper crustal-scale structures and have been reprocessed for our purpose. The models reveal that the ore body has formed during remobilisation of a proto-ore and is closely related to thrust zones that truncate the OKA. Later faults dismembered the ore explaining the variable depth of the different ore bodies along the Outokumpu ore zone. On a larger scale, at least four km-scale thrust sheets separated by major listric shear zones (curved dislocations in the seismic lines) can be recognized, each internally further imbricated by subordinate shear zones containing a number of lens-shape bodies of probably OKA rocks. Thrust stacking was followed by at least 3 stages of faulting that divided the ore belt into fault-bounded blocks with heterogeneous displacements: (i) NW-dipping faults with unresolved kinematics, (ii) reverse faulting along c.50°-60° SE

  14. 3-D Teaching Models for All

    ERIC Educational Resources Information Center

    Bradley, Joan; Farland-Smith, Donna

    2010-01-01

    Allowing a student to "see" through touch what other students see through a microscope can be a challenging task. Therefore, author Joan Bradley created three-dimensional (3-D) models with one student's visual impairment in mind. They are meant to benefit all students and can be used to teach common high school biology topics, including the…

  15. Constructing Arguments with 3-D Printed Models

    ERIC Educational Resources Information Center

    McConnell, William; Dickerson, Daniel

    2017-01-01

    In this article, the authors describe a fourth-grade lesson where 3-D printing technologies were not only a stimulus for engagement but also served as a modeling tool providing meaningful learning opportunities. Specifically, fourth-grade students construct an argument that animals' external structures function to support survival in a particular…

  16. Salt distribution in the Louisiana South Additions area from 3D seismic data

    SciTech Connect

    Jamieson, G.A.

    1996-12-31

    This paper outlines some preliminary observations based on a large interpretation project that was carried out with a grid of 3D time migrated seismic data, covering over 7,500 mi{sup 2} of the South Additions region of offshore Louisiana. Depth migrated data, covering a smaller subset of the study area, was also utilized in the interpretation. Top and base of salt were interpreted and the resulting maps have identified patterns of salt and weld geometry that show some regional trends. Historically, 2D time migrated seismic has been the primary dataset of most of the published regional salt studies. This paper focuses on areas where 3D time migrated data potentially shows most improvement over 2D data, specifically in the subsalt regions. In particular, relationships between base-of-salt keels, welds, basins, regional faulting and basement architecture are investigated. A generalized model is outlined to help explain the current salt geometry in the study area and comparisons are made with recently published salt evolution models.

  17. Model-based 3D SAR reconstruction

    NASA Astrophysics Data System (ADS)

    Knight, Chad; Gunther, Jake; Moon, Todd

    2014-06-01

    Three dimensional scene reconstruction with synthetic aperture radar (SAR) is desirable for target recognition and improved scene interpretability. The vertical aperture, which is critical to reconstruct 3D SAR scenes, is almost always sparsely sampled due to practical limitations, which creates an underdetermined problem. This papers explores 3D scene reconstruction using a convex model-based approach. The approach developed is demonstrated on 3D scenes, but can be extended to SAR reconstruction of sparsely sampled signals in the spatial and, or, frequency domains. The model-based approach enables knowledge-aided image formation (KAIF) by incorporating spatial, aspect, and sparsity magnitude terms into the image reconstruction. The incorporation of these terms, which are based on prior scene knowledge, will demonstrate improved results compared to traditional image formation algorithms. The SAR image formation problem is formulated as a second order cone program (SOCP) and the results are demonstrated on 3D scenes using simulated data and data from the GOTCHA data collect.1 The model-based results are contrasted against traditional backprojected images.

  18. Do-It-Yourself: 3D Models of Hydrogenic Orbitals through 3D Printing

    ERIC Educational Resources Information Center

    Griffith, Kaitlyn M.; de Cataldo, Riccardo; Fogarty, Keir H.

    2016-01-01

    Introductory chemistry students often have difficulty visualizing the 3-dimensional shapes of the hydrogenic electron orbitals without the aid of physical 3D models. Unfortunately, commercially available models can be quite expensive. 3D printing offers a solution for producing models of hydrogenic orbitals. 3D printing technology is widely…

  19. Debris Dispersion Model Using Java 3D

    NASA Technical Reports Server (NTRS)

    Thirumalainambi, Rajkumar; Bardina, Jorge

    2004-01-01

    This paper describes web based simulation of Shuttle launch operations and debris dispersion. Java 3D graphics provides geometric and visual content with suitable mathematical model and behaviors of Shuttle launch. Because the model is so heterogeneous and interrelated with various factors, 3D graphics combined with physical models provides mechanisms to understand the complexity of launch and range operations. The main focus in the modeling and simulation covers orbital dynamics and range safety. Range safety areas include destruct limit lines, telemetry and tracking and population risk near range. If there is an explosion of Shuttle during launch, debris dispersion is explained. The shuttle launch and range operations in this paper are discussed based on the operations from Kennedy Space Center, Florida, USA.

  20. 3D Seismic and Magnetic characterization of the Borax Lake Hydrothermal System in the Alvord Desert, southeastern Oregon.

    NASA Astrophysics Data System (ADS)

    Hess, S.; Bradford, J.; Lyle, M.; Routh, P.; Liberty, L.; Donaldson, P.

    2004-05-01

    throughout the survey area. Time slices through the 3D seismic cube show evidence of semi-continuous linear features consistent with the trend of the hot springs. A large scale inversion has been performed on the magnetic data. The fit to the observed data is good given the noise assumption of 3 nT. After more extensive processing, we will compare structures in the inverted magnetic model with features in the seismic data and explore the connection between the subsurface geology and the surface geometry of the hot springs.

  1. 3D finite-difference seismic migration with parallel computers

    SciTech Connect

    Ober, C.C.; Gjertsen, R.; Minkoff, S.; Womble, D.E.

    1998-11-01

    The ability to image complex geologies such as salt domes in the Gulf of Mexico and thrusts in mountainous regions is essential for reducing the risk associated with oil exploration. Imaging these structures, however, is computationally expensive as datasets can be terabytes in size. Traditional ray-tracing migration methods cannot handle complex velocity variations commonly found near such salt structures. Instead the authors use the full 3D acoustic wave equation, discretized via a finite difference algorithm. They reduce the cost of solving the apraxial wave equation by a number of numerical techniques including the method of fractional steps and pipelining the tridiagonal solves. The imaging code, Salvo, uses both frequency parallelism (generally 90% efficient) and spatial parallelism (65% efficient). Salvo has been tested on synthetic and real data and produces clear images of the subsurface even beneath complicated salt structures.

  2. 3D absolute hypocentral determination - 13 years of seismicity in Ecuadorian subduction zone

    NASA Astrophysics Data System (ADS)

    Font, Yvonne; Segovia, Monica; Theunissen, Thomas

    2010-05-01

    In Ecuador, the Nazca plate is subducting beneath the North Andean Block. This subduction triggered, during the last century, 4 major earthquakes of magnitude greater than 7.7. Between 1994 and 2007, the Geophysical Institute (Escuela National Politecnica, Quito) recorded about 40 000 events in whole Ecuador ranging from Mb 1.5 to 6.9. Unfortunately, the local network shows great density discrepancy between the Coastal and Andean regions where numerous stations were installed to survey volcanic activity. Consequently, seismicity in and around the interplate seismogenic zone - producer of the most destructive earthquakes and tsunamis - is not well constrained. This study aims to improve the location of 13 years seismicity occurred during an interseismic period in order to better localize the seismic deformation and gaps. The first step consists in the construction of a 3D "georealistic" velocity model. Because local tomography cannot provide satisfactory model, we combined all local crustal/lithospheric information on the geometry and velocity properties of different geological units. Those information cover the oceanic Nazca plate and sedimentary coverture the subducting plate dip angle; the North Andean Block margin composed of accreted oceanic plateaus (the Moho depth is approximated using gravity modeling); the metamorphic volcanic chain (oceanic nature for the occidental cordillera and inter-andean valley, continental one for the oriental cordillera); The continental Guyana shield and sedimentary basins. The resulting 3D velocity model extends from 2°N to 6.5°S and 277°E to 283°E and reaches a depth of 300 km. It is discretized in constant velocity blocks of 12 x 12 x 3 km in x, y and z, respectively. The second step consists in selecting an adequate sub-set of seismic stations in order to correct the effect of station density disequilibrium between coastal and volcanic regions. Consequently, we only keep the most representative volcanic stations in terms

  3. 3D geometry of the strain-field at transform plate boundaries: Implications for seismic rupture

    SciTech Connect

    Bodin, P.; Bilham, R. |

    1994-11-01

    We examine the amplitude and distribution of slip on vertical frictionless faults in the zone of concentrated shear strain that is characteristic of transform plate boundaries. We study both a 2D and a 3D approximation to this strain field. Mean displacements on ruptures within the zone of concentrated shear strain are proportional to the shear strain at failure when they are short, and are limited by plate displacements since the last major earthquake when they are long. The transition between these two behaviors occurs when the length of the dislocation approaches twice the thickness of the seismogenic crust, approximately the breadth of the zone of concentrated shear strain observed geodetically at transform plate boundaries. This result explains the observed non-linear scaling relation between seismic moment and rupture length. A geometrical consequence of the 3D model, in which the strain-field tapers downward, is that moderate earthquakes with rupture lengths similar to the thickness of the crust tend to slip more at depth than near the surface. Seismic moments estimated from surface slip in moderate earthquakes (M less than or equal to 7) will thus be underestimated. Shallow creep, if its along-strike dimension is extensive, can reduce a surface slip deficit that would otherwise develop on faults on which M less than 7 events are typical. In the absence of surface creep or other forms of off-fault deformation great earthquakes may be necessary features of transform boundaries with downward-tapering strain-fields.

  4. Illustrative visualization of 3D city models

    NASA Astrophysics Data System (ADS)

    Doellner, Juergen; Buchholz, Henrik; Nienhaus, Marc; Kirsch, Florian

    2005-03-01

    This paper presents an illustrative visualization technique that provides expressive representations of large-scale 3D city models, inspired by the tradition of artistic and cartographic visualizations typically found in bird"s-eye view and panoramic maps. We define a collection of city model components and a real-time multi-pass rendering algorithm that achieves comprehensible, abstract 3D city model depictions based on edge enhancement, color-based and shadow-based depth cues, and procedural facade texturing. Illustrative visualization provides an effective visual interface to urban spatial information and associated thematic information complementing visual interfaces based on the Virtual Reality paradigm, offering a huge potential for graphics design. Primary application areas include city and landscape planning, cartoon worlds in computer games, and tourist information systems.

  5. Poor boy 3D seismic effort yields South Central Kentucky discovery

    SciTech Connect

    Hanratty, M.

    1996-11-04

    Clinton County, Ky., is on the eastern flank of the Cincinnati arch and the western edge of the Appalachian basin and the Pine Mountain overthrust. Clinton County has long been known for high volume fractured carbonate wells. The discovery of these fractured reservoir, unfortunately, has historically been serendipitous. The author currently uses 2D seismic and satellite imagery to design 3D high resolution seismic shoots. This method has proven to be the most efficient and is the core of his program. The paper describes exploration methods, seismic acquisition, well data base, and seismic interpretation.

  6. Effect of 3-D viscoelastic structure on post-seismic relaxation from the 2004 M = 9.2 Sumatra earthquake

    USGS Publications Warehouse

    Pollitz, F.; Banerjee, P.; Grijalva, K.; Nagarajan, B.; Burgmann, R.

    2008-01-01

    The 2004 M=9.2 Sumatra-Andaman earthquake profoundly altered the state of stress in a large volume surrounding the ???1400 km long rupture. Induced mantle flow fields and coupled surface deformation are sensitive to the 3-D rheology structure. To predict the post-seismic motions from this earthquake, relaxation of a 3-D spherical viscoelastic earth model is simulated using the theory of coupled normal modes. The quasi-static deformation basis set and solution on the 3-D model is constructed using: a spherically stratified viscoelastic earth model with a linear stress-strain relation; an aspherical perturbation in viscoelastic structure; a 'static'mode basis set consisting of Earth's spheroidal and toroidal free oscillations; a "viscoelastic" mode basis set; and interaction kernels that describe the coupling among viscoelastic and static modes. Application to the 2004 Sumatra-Andaman earthquake illustrates the profound modification of the post-seismic flow field at depth by a slab structure and similarly large effects on the near-field post-seismic deformation field at Earth's surface. Comparison with post-seismic GPS observations illustrates the extent to which viscoelastic relaxation contributes to the regional post-seismic deformation. ?? Journal compilation ?? 2008 RAS.

  7. Testing & Validating: 3D Seismic Travel Time Tomography (Detailed Shallow Subsurface Imaging)

    NASA Astrophysics Data System (ADS)

    Marti, David; Marzan, Ignacio; Alvarez-Marron, Joaquina; Carbonell, Ramon

    2016-04-01

    A detailed full 3 dimensional P wave seismic velocity model was constrained by a high-resolution seismic tomography experiment. A regular and dense grid of shots and receivers was use to image a 500x500x200 m volume of the shallow subsurface. 10 GEODE's resulting in a 240 channels recording system and a 250 kg weight drop were used for the acquisition. The recording geometry consisted in 10x20m geophone grid spacing, and a 20x20 m stagered source spacing. A total of 1200 receivers and 676 source points. The study area is located within the Iberian Meseta, in Villar de Cañas (Cuenca, Spain). The lithological/geological target consisted in a Neogen sedimentary sequence formed from bottom to top by a transition from gyspum to silstones. The main objectives consisted in resolving the underground structure: contacts/discontinuities; constrain the 3D geometry of the lithology (possible cavities, faults/fractures). These targets were achieved by mapping the 3D distribution of the physical properties (P-wave velocity). The regularly space dense acquisition grid forced to acquire the survey in different stages and with a variety of weather conditions. Therefore, a careful quality control was required. More than a half million first arrivals were inverted to provide a 3D Vp velocity model that reached depths of 120 m in the areas with the highest ray coverage. An extended borehole campaign, that included borehole geophysical measurements in some wells provided unique tight constraints on the lithology an a validation scheme for the tomographic results. The final image reveals a laterally variable structure consisting of four different lithological units. In this methodological validation test travel-time tomography features a high capacity of imaging in detail the lithological contrasts for complex structures located at very shallow depths.

  8. 3-D model-based vehicle tracking.

    PubMed

    Lou, Jianguang; Tan, Tieniu; Hu, Weiming; Yang, Hao; Maybank, Steven J

    2005-10-01

    This paper aims at tracking vehicles from monocular intensity image sequences and presents an efficient and robust approach to three-dimensional (3-D) model-based vehicle tracking. Under the weak perspective assumption and the ground-plane constraint, the movements of model projection in the two-dimensional image plane can be decomposed into two motions: translation and rotation. They are the results of the corresponding movements of 3-D translation on the ground plane (GP) and rotation around the normal of the GP, which can be determined separately. A new metric based on point-to-line segment distance is proposed to evaluate the similarity between an image region and an instantiation of a 3-D vehicle model under a given pose. Based on this, we provide an efficient pose refinement method to refine the vehicle's pose parameters. An improved EKF is also proposed to track and to predict vehicle motion with a precise kinematics model. Experimental results with both indoor and outdoor data show that the algorithm obtains desirable performance even under severe occlusion and clutter.

  9. Sensing and compressing 3-D models

    SciTech Connect

    Krumm, J.

    1998-02-01

    The goal of this research project was to create a passive and robust computer vision system for producing 3-D computer models of arbitrary scenes. Although the authors were unsuccessful in achieving the overall goal, several components of this research have shown significant potential. Of particular interest is the application of parametric eigenspace methods for planar pose measurement of partially occluded objects in gray-level images. The techniques presented provide a simple, accurate, and robust solution to the planar pose measurement problem. In addition, the representational efficiency of eigenspace methods used with gray-level features were successfully extended to binary features, which are less sensitive to illumination changes. The results of this research are presented in two papers that were written during the course of this project. The papers are included in sections 2 and 3. The first section of this report summarizes the 3-D modeling efforts.

  10. Q AS A LITHOLOGICAL/HYDROCARBON INDICATOR: FROM FULL WAVEFORM SONIC TO 3D SURFACE SEISMIC

    SciTech Connect

    Jorge O. Parra; C.L. Hackert; L. Wilson; H.A. Collier; J. Todd Thomas

    2006-03-31

    The goal of this project was to develop a method to exploit viscoelastic rock and fluid properties to greatly enhance the sensitivity of surface seismic measurements to the presence of hydrocarbon saturation. To reach the objective, Southwest Research Institute scientists used well log, lithology, production, and 3D seismic data from an oil reservoir located on the Waggoner Ranch in north central Texas. The project was organized in three phases. In the first phase, we applied modeling techniques to investigate seismic- and acoustic-frequency wave attenuation and its effect on observable wave attributes. We also gathered existing data and acquired new data from the Waggoner Ranch field, so that all needed information was in place for the second phase. During the second phase, we developed methods to extract attenuation from borehole acoustic and surface seismic data. These methods were tested on synthetic data constructed from realistic models and real data. In the third and final phase of the project, we applied this technology to a full data set from the Waggoner site. The results presented in this Final Report show that geological conditions at the site did not allow us to obtain interpretable results from the Q processing algorithm for 3D seismic data. However, the Q-log processing algorithm was successfully applied to full waveform sonic data from the Waggoner site. A significant part of this project was technology transfer. We have published several papers and conducted presentations at professional conferences. In particular, we presented the Q-log algorithm and applications at the Society of Exploration Geophysicists (SEG) Development and Production Forum in Austin, Texas, in May 2005. The presentation attracted significant interest from the attendees and, at the request of the SEG delegates, it was placed on the Southwest Research Institute Internet site. The presentation can be obtained from the following link: http://www.swri.org/4org/d15/elecsys

  11. Vision models for 3D surfaces

    NASA Astrophysics Data System (ADS)

    Mitra, Sunanda

    1992-11-01

    Different approaches to computational stereo to represent human stereo vision have been developed over the past two decades. The Marr-Poggio theory of human stereo vision is probably the most widely accepted model of the human stereo vision. However, recently developed motion stereo models which use a sequence of images taken by either a moving camera or a moving object provide an alternative method of achieving multi-resolution matching without the use of Laplacian of Gaussian operators. While using image sequences, the baseline between two camera positions for a image pair is changed for the subsequent image pair so as to achieve different resolution for each image pair. Having different baselines also avoids the inherent occlusion problem in stereo vision models. The advantage of using multi-resolution images acquired by camera positioned at different baselines over those acquired by LOG operators is that one does not have to encounter spurious edges often created by zero-crossings in the LOG operated images. Therefore in designing a computer vision system, a motion stereo model is more appropriate than a stereo vision model. However, in some applications where only a stereo pair of images are available, recovery of 3D surfaces of natural scenes are possible in a computationally efficient manner by using cepstrum matching and regularization techniques. Section 2 of this paper describes a motion stereo model using multi-scale cepstrum matching for the detection of disparity between image pairs in a sequence of images and subsequent recovery of 3D surfaces from depth-map obtained by a non convergent triangulation technique. Section 3 presents a 3D surface recovery technique from a stereo pair using cepstrum matching for disparity detection and cubic B-splines for surface smoothing. Section 4 contains the results of 3D surface recovery using both of the techniques mentioned above. Section 5 discusses the merit of 2D cepstrum matching and cubic B

  12. Deep 3-D seismic reflection imaging of Precambrian sills in the crystalline crust of Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Welford, Joanna Kim

    2005-07-01

    Using deep 3-D seismic reflection datasets collected by the Canadian petroleum exploration industry in southwestern and northwestern Alberta, the Head-Smashed-In and Winagami Precambrian sill complexes within the crystalline upper crust, previously identified on Lithoprobe 2-D multichannel reflection lines, are investigated to determine their 3-D geometries and reflective characteristics. During seismic processing of the dataset in southwestern Alberta, a recently developed wavelet-based method, Physical Wavelet Frame Denoising, is applied and shown to successfully suppress ground roll contamination while preserving low frequency signals from deeper structures. A new 3-D empirical trace interpolation scheme, DSInt, is developed to address the problem of spatial aliasing associated with 3-D data acquisition. Results from applying the algorithm to both datasets are comparable to available interpolation codes while allowing for greater flexibility in the handling of irregular acquisition geometries and interpolated trace headers. Evidence of the Head-Smashed-In reflector in southwestern Alberta is obtained using a dataset acquired to 8 s TWTT (approx. 24 km depth). From locally coherent, discontinuous pockets of basement reflectivity, the dataset appears to image the tapering western edge of the deep reflections imaged by Lithoprobe. A statistical approach of tracking reflectivity is developed and applied to obtain the spatial and temporal distribution of reflections. Simple 1-D forward modelling results reveal that the brightest reflections likely arise from a 50 to 150 m thick body of high density/high velocity material although variations in the amplitudes and lateral distribution of the reflections indicate that the thickness of the sills is laterally variable. Thus, the results are consistent with imaging the tapering edge of the sill complex. Clear evidence of the Winagami reflection sequence in northwestern Alberta, emerges from the second dataset acquired to 5

  13. Robust hashing for 3D models

    NASA Astrophysics Data System (ADS)

    Berchtold, Waldemar; Schäfer, Marcel; Rettig, Michael; Steinebach, Martin

    2014-02-01

    3D models and applications are of utmost interest in both science and industry. With the increment of their usage, their number and thereby the challenge to correctly identify them increases. Content identification is commonly done by cryptographic hashes. However, they fail as a solution in application scenarios such as computer aided design (CAD), scientific visualization or video games, because even the smallest alteration of the 3D model, e.g. conversion or compression operations, massively changes the cryptographic hash as well. Therefore, this work presents a robust hashing algorithm for 3D mesh data. The algorithm applies several different bit extraction methods. They are built to resist desired alterations of the model as well as malicious attacks intending to prevent correct allocation. The different bit extraction methods are tested against each other and, as far as possible, the hashing algorithm is compared to the state of the art. The parameters tested are robustness, security and runtime performance as well as False Acceptance Rate (FAR) and False Rejection Rate (FRR), also the probability calculation of hash collision is included. The introduced hashing algorithm is kept adaptive e.g. in hash length, to serve as a proper tool for all applications in practice.

  14. Fallon FORGE 3D Geologic Model

    SciTech Connect

    Doug Blankenship

    2016-03-01

    An x,y,z scattered data file for the 3D geologic model of the Fallon FORGE site. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  15. Inferential modeling of 3D chromatin structure.

    PubMed

    Wang, Siyu; Xu, Jinbo; Zeng, Jianyang

    2015-04-30

    For eukaryotic cells, the biological processes involving regulatory DNA elements play an important role in cell cycle. Understanding 3D spatial arrangements of chromosomes and revealing long-range chromatin interactions are critical to decipher these biological processes. In recent years, chromosome conformation capture (3C) related techniques have been developed to measure the interaction frequencies between long-range genome loci, which have provided a great opportunity to decode the 3D organization of the genome. In this paper, we develop a new Bayesian framework to derive the 3D architecture of a chromosome from 3C-based data. By modeling each chromosome as a polymer chain, we define the conformational energy based on our current knowledge on polymer physics and use it as prior information in the Bayesian framework. We also propose an expectation-maximization (EM) based algorithm to estimate the unknown parameters of the Bayesian model and infer an ensemble of chromatin structures based on interaction frequency data. We have validated our Bayesian inference approach through cross-validation and verified the computed chromatin conformations using the geometric constraints derived from fluorescence in situ hybridization (FISH) experiments. We have further confirmed the inferred chromatin structures using the known genetic interactions derived from other studies in the literature. Our test results have indicated that our Bayesian framework can compute an accurate ensemble of 3D chromatin conformations that best interpret the distance constraints derived from 3C-based data and also agree with other sources of geometric constraints derived from experimental evidence in the previous studies. The source code of our approach can be found in https://github.com/wangsy11/InfMod3DGen.

  16. 3D Tromso survey planning: Cost efficiency through seismic data quality

    SciTech Connect

    Savini, L.; La Bella, G.; Ronchitelli, G.; Seldal, J.

    1996-12-31

    The approach described in this case history allows for the production of a full 3D dataset in order to solve the interpretation problems of the area at reduced cost. The structural definition of the main prospects in the area was unclear, mainly due to the poor quality of 2D seismic data. The committed 2D seismic survey would have probably supplied a seismic-data set of slightly better quality, but on the other hand, there would not have been a suitable improvement in the imaging of the main prospects. In an attempt to overcome these problems, an Explorative 3D survey was planned. In order to ensure a proper quality of the 3D dataset, an integrated approach to the acquisition and processing planning was adopted. Acquisition was carried out utilizing skipped configuration capable of acquiring 12 CMP lines for each sail line with a considerable reduction in cost.

  17. 3-D physical modeling of a complex salt canopy

    SciTech Connect

    Wiley, R.W.; Sekharan, K.K.

    1996-12-31

    Recent drilling has confirmed both significant reservoir potential and the presence of commercial hydrocarbons below salt structures in the Gulf of Mexico. Obtaining definitive seismic images with standard processing schemes beneath these salt structures is very difficult if not impossible. Because of the complicated seismic behavior of these structures, full volume 3-D prestack depth migration is required. Unfortunately, carrying out the multitude of calculations needed to create a proper image requires the largest and fastest supercomputers and rather complex numerical algorithms. Furthermore, developing and testing the imaging algorithms is quite involved and requires appropriate test data sets. To better understand the problems and issues of subsalt imaging, Marathon Oil Company and Louisiana Land and Exploration Company contracted with the University of Houston`s Allied Geophysical Laboratories (AGL) to construct a salt canopy physical model. The model is patterned after the SEG/EAEG Salt Model and is made from synthetic materials. It is a full three-dimensional model with an irregularly shaped, lateral salt structure embedded in five distinct sedimentary layers. The model was used to acquire a multi-offset 3-D marine-style survey. These data are being used to address problems of subsalt imaging. In addition to standard processing techniques, the authors investigate algorithms for multiple removal and prestack depth migration.

  18. 3D Geological Model for "LUSI" - a Deep Geothermal System

    NASA Astrophysics Data System (ADS)

    Sohrabi, Reza; Jansen, Gunnar; Mazzini, Adriano; Galvan, Boris; Miller, Stephen A.

    2016-04-01

    Geothermal applications require the correct simulation of flow and heat transport processes in porous media, and many of these media, like deep volcanic hydrothermal systems, host a certain degree of fracturing. This work aims to understand the heat and fluid transport within a new-born sedimentary hosted geothermal system, termed Lusi, that began erupting in 2006 in East Java, Indonesia. Our goal is to develop conceptual and numerical models capable of simulating multiphase flow within large-scale fractured reservoirs such as the Lusi region, with fractures of arbitrary size, orientation and shape. Additionally, these models can also address a number of other applications, including Enhanced Geothermal Systems (EGS), CO2 sequestration (Carbon Capture and Storage CCS), and nuclear waste isolation. Fractured systems are ubiquitous, with a wide-range of lengths and scales, making difficult the development of a general model that can easily handle this complexity. We are developing a flexible continuum approach with an efficient, accurate numerical simulator based on an appropriate 3D geological model representing the structure of the deep geothermal reservoir. Using previous studies, borehole information and seismic data obtained in the framework of the Lusi Lab project (ERC grant n°308126), we present here the first 3D geological model of Lusi. This model is calculated using implicit 3D potential field or multi-potential fields, depending on the geological context and complexity. This method is based on geological pile containing the geological history of the area and relationship between geological bodies allowing automatic computation of intersections and volume reconstruction. Based on the 3D geological model, we developed a new mesh algorithm to create hexahedral octree meshes to transfer the structural geological information for 3D numerical simulations to quantify Thermal-Hydraulic-Mechanical-Chemical (THMC) physical processes.

  19. Successful gas hydrate prospecting using 3D seismic - A case study for the Mt. Elbert prospect, Milne Point, North Slope Alaska

    USGS Publications Warehouse

    Inks, T.L.; Agena, W.F.

    2008-01-01

    In February 2007, the Mt. Elbert Prospect stratigraphic test well, Milne Point, North Slope Alaska encountered thick methane gas hydrate intervals, as predicted by 3D seismic interpretation and modeling. Methane gas hydrate-saturated sediment was found in two intervals, totaling more than 100 ft., identified and mapped based on seismic character and wavelet modeling.

  20. 3D Model of Surfactant Replacement Therapy

    NASA Astrophysics Data System (ADS)

    Grotberg, James; Tai, Cheng-Feng; Filoche, Marcel

    2015-11-01

    Surfactant Replacement Therapy (SRT) involves instillation of a liquid-surfactant mixture directly into the lung airway tree. Though successful in neonatal applications, its use in adults had early success followed by failure. We present the first mathematical model of 3D SRT where a liquid plug propagates through the tree from forced inspiration. In two separate modeling steps, the plug first deposits a coating film on the airway wall which subtracts from its volume, a ``coating cost''. Then the plug splits unevenly at the airway bifurcation due to gravity. The steps are repeated until a plug ruptures or reaches the tree endpoint alveoli/acinus. The model generates 3D images of the resulting acinar distribution and calculates two global indexes, efficiency and homogeneity. Simulating published literature, the earlier successful adult SRT studies show comparatively good index values, while the later failed studies do not. Those unsuccessful studies used smaller dose volumes with higher concentration mixtures, apparently assuming a well mixed compartment. The model shows that adult lungs are not well mixed in SRT due to the coating cost and gravity effects. Returning to the higher dose volume protocols could save many thousands of lives annually in the US. Supported by NIH Grants HL85156, HL84370 and Agence Nationale de la Recherche, ANR no. 2010-BLAN-1119-05.

  1. MOSSFRAC: An anisotropic 3D fracture model

    SciTech Connect

    Moss, W C; Levatin, J L

    2006-08-14

    Despite the intense effort for nearly half a century to construct detailed numerical models of plastic flow and plastic damage accumulation, models for describing fracture, an equally important damage mechanism still cannot describe basic fracture phenomena. Typical fracture models set the stress tensor to zero for tensile fracture and set the deviatoric stress tensor to zero for compressive fracture. One consequence is that the simple case of the tensile fracture of a cylinder under combined compressive radial and tensile axial loads is not modeled correctly. The experimental result is a cylinder that can support compressive radial loads, but no axial load, whereas, the typical numerical result is a cylinder with all stresses equal to zero. This incorrect modeling of fracture locally also has a global effect, because material that is fracturing produces stress release waves, which propagate from the fracture and influence the surrounding material. Consequently, it would be useful to have a model that can describe the stress relief and the resulting anisotropy due to fracture. MOSSFRAC is a material model that simulates three-dimensional tensile and shear fracture in initially isotropic elastic-plastic materials, although its framework is also amenable to initially anisotropic materials. It differs from other models by accounting for the effects of cracks on the constitutive response of the material, so that the previously described experiment, as well as complicated fracture scenarios are simulated more accurately. The model is implemented currently in the LLNL hydrocodes DYNA3D, PARADYN, and ALE3D. The purpose of this technical note is to present a complete qualitative description of the model and quantitative descriptions of salient features.

  2. Thrust fault segmentation and downward fault propagation in accretionary wedges: New Insights from 3D seismic reflection data

    NASA Astrophysics Data System (ADS)

    Orme, Haydn; Bell, Rebecca; Jackson, Christopher

    2016-04-01

    The shallow parts of subduction megathrust faults are typically thought to be aseismic and incapable of propagating seismic rupture. The 2011 Tohoku-Oki earthquake, however, ruptured all the way to the trench, proving that in some locations rupture can propagate through the accretionary wedge. An improved understanding of the structural character and physical properties of accretionary wedges is therefore crucial to begin to assess why such anomalously shallow seismic rupture occurs. Despite its importance, we know surprisingly little regarding the 3D geometry and kinematics of thrust network development in accretionary prisms, largely due to a lack of 3D seismic reflection data providing high-resolution, 3D images of entire networks. Thus our current understanding is largely underpinned by observations from analogue and numerical modelling, with limited observational data from natural examples. In this contribution we use PSDM, 3D seismic reflection data from the Nankai margin (3D Muroto dataset, available from the UTIG Academic Seismic Portal, Marine Geoscience Data System) to examine how imbricate thrust fault networks evolve during accretionary wedge growth. We unravel the evolution of faults within the protothrust and imbricate thrust zones by interpreting multiple horizons across faults and measuring fault displacement and fold amplitude along-strike; by doing this, we are able to investigate the three dimensional accrual of strain. We document a number of local displacement minima along-strike of faults, suggesting that, the protothrust and imbricate thrusts developed from the linkage of smaller, previously isolated fault segments. Although we often assume imbricate faults are likely to have propagated upwards from the décollement we show strong evidence for fault nucleation at shallow depths and downward propagation to intersect the décollement. The complex fault interactions documented here have implications for hydraulic compartmentalisation and pore

  3. Automatic detection of karstic sinkholes in seismic 3D images using circular Hough transform

    NASA Astrophysics Data System (ADS)

    Heydari Parchkoohi, Mostafa; Keshavarz Farajkhah, Nasser; Salimi Delshad, Meysam

    2015-10-01

    More than 30% of hydrocarbon reservoirs are reported in carbonates that mostly include evidence of fractures and karstification. Generally, the detection of karstic sinkholes prognosticate good quality hydrocarbon reservoirs where looser sediments fill the holes penetrating hard limestone and the overburden pressure on infill sediments is mostly tolerated by their sturdier surrounding structure. They are also useful for the detection of erosional surfaces in seismic stratigraphic studies and imply possible relative sea level fall at the time of establishment. Karstic sinkholes are identified straightforwardly by using seismic geometric attributes (e.g. coherency, curvature) in which lateral variations are much more emphasized with respect to the original 3D seismic image. Then, seismic interpreters rely on their visual skills and experience in detecting roughly round objects in seismic attribute maps. In this paper, we introduce an image processing workflow to enhance selective edges in seismic attribute volumes stemming from karstic sinkholes and finally locate them in a high quality 3D seismic image by using circular Hough transform. Afterwards, we present a case study from an on-shore oilfield in southwest Iran, in which the proposed algorithm is applied and karstic sinkholes are traced.

  4. Areal 3-D seismic technique for reservoir delineation: Case history from offshore Niger Delta

    SciTech Connect

    Idowu, A.O. )

    1993-02-01

    In the 1950s, early exploration period in the Niger Delta witnessed the use of 2-D (two dimensional) seismic reflection method which adequate for imaging large subsurface geologic features including growth faulting and roll-over anticlines. This technique involves the Common-Depth-Point method (CDP) which acquires a plane of seismic information in distance along the surface and in time into the geological section, and is used to improve the signal-to-noise (S/N) ratio, to remove multiples and consequently give a representation of the subsurface particularly if the data are collected up- or downdip. By mid-1980s, the obvious geological structures have, in general, been discovered and it became necessary to adopt a more sophisticated technique such as the 3-D (three dimensional) seismic method to delineate more subtle reservoirs and resolve complex fault patterns in order to aid exploration as well as facilitate efficient field development. The case history discussed in this paper involves the use of areal 3-D seismic method for delineating the reservoir characterization of the O-field located in a shallow water area of the western Niger Delta. The areal 3-D seismic technique is superior to the earlier CDP method in that a cube of seismic data can be collected in two dimensions in space and one in time by a variety of techniques including the swath seismic shooting pattern adopted for gathering the 3-D data for the O-field's reservoir which involves the line of sources. The objective is to adequately sample the subsurface so that changes in various parameters such as the amplitude phase or power in the siesmic signal or velocity of propagation can be mapped areally and interpreted as an indication of changes in the physical properties of the rock matrix.

  5. 3-D GRACE gravity model for the 2011 Japan earthquake

    NASA Astrophysics Data System (ADS)

    Sastry, Rambhatla G.; Sonker, Mahendra K.

    2017-02-01

    The GRACE mission has contributed to the seismic characterization of major earthquakes in offshore regions of the world. Here, we isolate satellite gravity signal (μGal range) for the Japan Earthquake of 2011 using a difference method. Contrary to the existing gravity models, we propose a unit vertical pyramid based five-layer 3-D thrust fault model, which extends to the hypocenter and honors the ocean water layer and sea floor upheaval also. Our model partly uses existing seismological information (hypocenter depth of 32 km, rupture length of 300 km and vertical slip of 4 m), provides a snapshot of episodic subduction of the Pacific Plate below the Atlantic Plate and its gravity response closely matches the observed gravity (RMS error of 3.4012×10-13μGal), fully accounting for co-seismic mass redistribution including sea surface deformation. Our inferred rupture length, rupture velocity, average seismic moment magnitude and momentum, respectively, are 300 km, 4.49 km/s, 1.152×1021-1.8816×1021 N m and 2.319×106 GNs, which fairly agree with the literature. Further, our model inferred momentum at the sea floor corresponds to an area pulse that led to Tsunami generation.

  6. 3D Stratigraphic Modeling of Central Aachen

    NASA Astrophysics Data System (ADS)

    Dong, M.; Neukum, C.; Azzam, R.; Hu, H.

    2010-05-01

    Since 1980s, advanced computer hardware and software technologies, as well as multidisciplinary research have provided possibilities to develop advanced three dimensional (3D) simulation software for geosciences application. Some countries, such as USA1) and Canada2) 3), have built up regional 3D geological models based on archival geological data. Such models have played huge roles in engineering geology2), hydrogeology2) 3), geothermal industry1) and so on. In cooperating with the Municipality of Aachen, the Department of Engineering Geology of RWTH Aachen University have built up a computer-based 3D stratigraphic model of 50 meter' depth for the center of Aachen, which is a 5 km by 7 km geologically complex area. The uncorrelated data from multi-resources, discontinuous nature and unconformable connection of the units are main challenges for geological modeling in this area. The reliability of 3D geological models largely depends on the quality and quantity of data. Existing 1D and 2D geological data were collected, including 1) approximately 6970 borehole data of different depth compiled in Microsoft Access database and MapInfo database; 2) a Digital Elevation Model (DEM); 3) geological cross sections; and 4) stratigraphic maps in 1m, 2m and 5m depth. Since acquired data are of variable origins, they were managed step by step. The main processes are described below: 1) Typing errors of borehole data were identified and the corrected data were exported to Variowin2.2 to distinguish duplicate points; 2) The surface elevation of borehole data was compared to the DEM, and differences larger than 3m were eliminated. Moreover, where elevation data missed, it was read from the DEM; 3) Considerable data were collected from municipal constructions, such as residential buildings, factories, and roads. Therefore, many boreholes are spatially clustered, and only one or two representative points were picked out in such areas; After above procedures, 5839 boreholes with -x

  7. Evaluation of Jumping and Creeping Regularization Approaches Applied to 3D Seismic Tomography

    NASA Astrophysics Data System (ADS)

    Liu, M.; Ramachandran, K.

    2011-12-01

    are evaluated on a synthetic 3-D true model obtained from a large scale experiment. The evaluation is performed for jumping and creeping approaches for various levels of smoothing constraints, and initial models. The final models are compared against the true models to compute residual distance between the models. Horizontal and vertical roughness in the final models are computed and compared with the true model roughness. Correlation between the true and final models is computed to evaluate the similarities of spatial patterns in the models. The study is also used to show that average 1-D models derived from the final models are very close, indicating that this will be an optimal approach to construct 1-D starting models.

  8. An optimal transport approach for seismic tomography: application to 3D full waveform inversion

    NASA Astrophysics Data System (ADS)

    Métivier, L.; Brossier, R.; Mérigot, Q.; Oudet, E.; Virieux, J.

    2016-11-01

    The use of optimal transport distance has recently yielded significant progress in image processing for pattern recognition, shape identification, and histograms matching. In this study, the use of this distance is investigated for a seismic tomography problem exploiting the complete waveform; the full waveform inversion. In its conventional formulation, this high resolution seismic imaging method is based on the minimization of the L 2 distance between predicted and observed data. Application of this method is generally hampered by the local minima of the associated L 2 misfit function, which correspond to velocity models matching the data up to one or several phase shifts. Conversely, the optimal transport distance appears as a more suitable tool to compare the misfit between oscillatory signals, for its ability to detect shifted patterns. However, its application to the full waveform inversion is not straightforward, as the mass conservation between the compared data cannot be guaranteed, a crucial assumption for optimal transport. In this study, the use of a distance based on the Kantorovich-Rubinstein norm is introduced to overcome this difficulty. Its mathematical link with the optimal transport distance is made clear. An efficient numerical strategy for its computation, based on a proximal splitting technique, is introduced. We demonstrate that each iteration of the corresponding algorithm requires solving the Poisson equation, for which fast solvers can be used, relying either on the fast Fourier transform or on multigrid techniques. The development of this numerical method make possible applications to industrial scale data, involving tenths of millions of discrete unknowns. The results we obtain on such large scale synthetic data illustrate the potentialities of the optimal transport for seismic imaging. Starting from crude initial velocity models, optimal transport based inversion yields significantly better velocity reconstructions than those based on

  9. Seismic Hazard Maps for Seattle, Washington, Incorporating 3D Sedimentary Basin Effects, Nonlinear Site Response, and Rupture Directivity

    USGS Publications Warehouse

    Frankel, Arthur D.; Stephenson, William J.; Carver, David L.; Williams, Robert A.; Odum, Jack K.; Rhea, Susan

    2007-01-01

    This report presents probabilistic seismic hazard maps for Seattle, Washington, based on over 500 3D simulations of ground motions from scenario earthquakes. These maps include 3D sedimentary basin effects and rupture directivity. Nonlinear site response for soft-soil sites of fill and alluvium was also applied in the maps. The report describes the methodology for incorporating source and site dependent amplification factors into a probabilistic seismic hazard calculation. 3D simulations were conducted for the various earthquake sources that can affect Seattle: Seattle fault zone, Cascadia subduction zone, South Whidbey Island fault, and background shallow and deep earthquakes. The maps presented in this document used essentially the same set of faults and distributed-earthquake sources as in the 2002 national seismic hazard maps. The 3D velocity model utilized in the simulations was validated by modeling the amplitudes and waveforms of observed seismograms from five earthquakes in the region, including the 2001 M6.8 Nisqually earthquake. The probabilistic seismic hazard maps presented here depict 1 Hz response spectral accelerations with 10%, 5%, and 2% probabilities of exceedance in 50 years. The maps are based on determinations of seismic hazard for 7236 sites with a spacing of 280 m. The maps show that the most hazardous locations for this frequency band (around 1 Hz) are soft-soil sites (fill and alluvium) within the Seattle basin and along the inferred trace of the frontal fault of the Seattle fault zone. The next highest hazard is typically found for soft-soil sites in the Duwamish Valley south of the Seattle basin. In general, stiff-soil sites in the Seattle basin exhibit higher hazard than stiff-soil sites outside the basin. Sites with shallow bedrock outside the Seattle basin have the lowest estimated hazard for this frequency band.

  10. Identifying High Potential Well Targets with 3D Seismic and Mineralogy

    SciTech Connect

    Mellors, R. J.

    2015-10-30

    Seismic reflection the primary tool used in petroleum exploration and production, but use in geothermal exploration is less standard, in part due to cost but also due to the challenges in identifying the highly-permeable zones essential for economic hydrothermal systems [e.g. Louie et al., 2011; Majer, 2003]. Newer technology, such as wireless sensors and low-cost high performance computing, has helped reduce the cost and effort needed to conduct 3D surveys. The second difficulty, identifying permeable zones, has been less tractable so far. Here we report on the use of seismic attributes from a 3D seismic survey to identify and map permeable zones in a hydrothermal area.

  11. Well log analysis to assist the interpretation of 3-D seismic data at Milne Point, north slope of Alaska

    USGS Publications Warehouse

    Lee, Myung W.

    2005-01-01

    In order to assess the resource potential of gas hydrate deposits in the North Slope of Alaska, 3-D seismic and well data at Milne Point were obtained from BP Exploration (Alaska), Inc. The well-log analysis has three primary purposes: (1) Estimate gas hydrate or gas saturations from the well logs; (2) predict P-wave velocity where there is no measured P-wave velocity in order to generate synthetic seismograms; and (3) edit P-wave velocities where degraded borehole conditions, such as washouts, affected the P-wave measurement significantly. Edited/predicted P-wave velocities were needed to map the gas-hydrate-bearing horizons in the complexly faulted upper part of 3-D seismic volume. The estimated gas-hydrate/gas saturations from the well logs were used to relate to seismic attributes in order to map regional distribution of gas hydrate inside the 3-D seismic grid. The P-wave velocities were predicted using the modified Biot-Gassmann theory, herein referred to as BGTL, with gas-hydrate saturations estimated from the resistivity logs, porosity, and clay volume content. The effect of gas on velocities was modeled using the classical Biot-Gassman theory (BGT) with parameters estimated from BGTL.

  12. SB3D User Manual, Santa Barbara 3D Radiative Transfer Model

    SciTech Connect

    O'Hirok, William

    1999-01-01

    SB3D is a three-dimensional atmospheric and oceanic radiative transfer model for the Solar spectrum. The microphysics employed in the model are the same as used in the model SBDART. It is assumed that the user of SB3D is familiar with SBDART and IDL. SB3D differs from SBDART in that computations are conducted on media in three-dimensions rather than a single column (i.e. plane-parallel), and a stochastic method (Monte Carlo) is employed instead of a numerical approach (Discrete Ordinates) for estimating a solution to the radiative transfer equation. Because of these two differences between SB3D and SBDART, the input and running of SB3D is more unwieldy and requires compromises between model performance and computational expense. Hence, there is no one correct method for running the model and the user must develop a sense to the proper input and configuration of the model.

  13. 3D P-wave velocity structure of the deep Galicia rifted margin: A first analysis of the Galicia 3D wide-angle seismic dataset

    NASA Astrophysics Data System (ADS)

    Bayrakci, Gaye; Minshull, Timothy A.; Davy, Richard G.; Karplus, Marianne S.; Kaeschen, Dirk; Papenberg, Cord; Krabbenhoeft, Anne; Sawyer, Dale; Reston, Timothy J.; Shillington, Donna J.; Ranero, César R.

    2014-05-01

    Galicia 3D, a reflection-refraction and long offset seismic experiment was carried out from May through September 2013, at the Galicia rifted margin (in the northeast Atlantic Ocean, west of Spain) as a collaboration between US, UK, German and Spanish groups. The 3D multichannel seismic acquisition conducted by R/V Marcus Langseth covered a 64 km by 20 km (1280 km2) zone where the main geological features are the Peridotite Ridge (PR), composed of serpentinized peridotite and thought be upper mantle exhumed to the seafloor during rifting, and the S reflector which has been interpreted to be a low angle detachment fault overlain by fault bounded, rotated, continental crustal blocks. In the 3D box, two airgun arrays of 3300 cu.in. were fired alternately (in flip-flop configuration) every 37.5 m. All shots are recorded by 44 short period four component ocean bottom seismometers (OBS) and 26 ocean bottom hydrophones (OBH) deployed and recovered by R/V Poseidon, as well as four 6 km hydrophone streamers with 12.5 m channel spacing towed by R/V Marcus Langseth. We present the preliminary results of the first arrival time tomography study which is carried out with a subset of the wide-angle dataset, in order to generate a 3D P-wave velocity volume for the entire depth sampled by the reflection data. After the relocation of OBSs and OBHs, an automatic first-arrival time picking approach is applied to a subset of the dataset, which comprises more than 5.5 million source-receiver pairs. Then, the first-arrival times are checked visually, in 3-dimensions. The a priori model used for the first-arrival time tomography is built up using information from previous seismic surveys carried out at the Galicia margin (e.g. ISE, 1997). The FAST algorithm of Zelt and Barton (1998) is used for the first-arrival time inversion. The 3D P-wave velocity volume can be used in interpreting the reflection dataset, as a starting point for migration, to quantify the thinning of the crustal layers

  14. Scalable 3D GIS environment managed by 3D-XML-based modeling

    NASA Astrophysics Data System (ADS)

    Shi, Beiqi; Rui, Jianxun; Chen, Neng

    2008-10-01

    Nowadays, the namely 3D GIS technologies become a key factor in establishing and maintaining large-scale 3D geoinformation services. However, with the rapidly increasing size and complexity of the 3D models being acquired, a pressing needed for suitable data management solutions has become apparent. This paper outlines that storage and exchange of geospatial data between databases and different front ends like 3D models, GIS or internet browsers require a standardized format which is capable to represent instances of 3D GIS models, to minimize loss of information during data transfer and to reduce interface development efforts. After a review of previous methods for spatial 3D data management, a universal lightweight XML-based format for quick and easy sharing of 3D GIS data is presented. 3D data management based on XML is a solution meeting the requirements as stated, which can provide an efficient means for opening a new standard way to create an arbitrary data structure and share it over the Internet. To manage reality-based 3D models, this paper uses 3DXML produced by Dassault Systemes. 3DXML uses opening XML schemas to communicate product geometry, structure and graphical display properties. It can be read, written and enriched by standard tools; and allows users to add extensions based on their own specific requirements. The paper concludes with the presentation of projects from application areas which will benefit from the functionality presented above.

  15. Advancing New 3D Seismic Interpretation Methods for Exploration and Development of Fractured Tight Gas Reservoirs

    SciTech Connect

    James Reeves

    2005-01-31

    In a study funded by the U.S. Department of Energy and GeoSpectrum, Inc., new P-wave 3D seismic interpretation methods to characterize fractured gas reservoirs are developed. A data driven exploratory approach is used to determine empirical relationships for reservoir properties. Fractures are predicted using seismic lineament mapping through a series of horizon and time slices in the reservoir zone. A seismic lineament is a linear feature seen in a slice through the seismic volume that has negligible vertical offset. We interpret that in regions of high seismic lineament density there is a greater likelihood of fractured reservoir. Seismic AVO attributes are developed to map brittle reservoir rock (low clay) and gas content. Brittle rocks are interpreted to be more fractured when seismic lineaments are present. The most important attribute developed in this study is the gas sensitive phase gradient (a new AVO attribute), as reservoir fractures may provide a plumbing system for both water and gas. Success is obtained when economic gas and oil discoveries are found. In a gas field previously plagued with poor drilling results, four new wells were spotted using the new methodology and recently drilled. The wells have estimated best of 12-months production indicators of 2106, 1652, 941, and 227 MCFGPD. The latter well was drilled in a region of swarming seismic lineaments but has poor gas sensitive phase gradient (AVO) and clay volume attributes. GeoSpectrum advised the unit operators that this location did not appear to have significant Lower Dakota gas before the well was drilled. The other three wells are considered good wells in this part of the basin and among the best wells in the area. These new drilling results have nearly doubled the gas production and the value of the field. The interpretation method is ready for commercialization and gas exploration and development. The new technology is adaptable to conventional lower cost 3D seismic surveys.

  16. Reservoir lithofacies analysis using 3D seismic data in dissimilarity space

    NASA Astrophysics Data System (ADS)

    Bagheri, M.; Riahi, M. A.; Hashemi, H.

    2013-06-01

    Seismic data interpretation is one of the most important steps in exploration seismology. Seismic facies analysis (SFA) with emphasis on lithofacies can be used to extract more information about structures and geology, which results in seismic interpretation enhancement. Facies analysis is based on unsupervised and supervised classification using seismic attributes. In this paper, supervised classification by a support vector machine using well logs and seismic attributes is applied. Dissimilarity as a new measuring space is employed, after which classification is carried out. Often, SFA is carried out in a feature space in which each dimension stands as a seismic attribute. Different facies show lots of class overlap in the feature space; hence, high classification error values are reported. Therefore, decreasing class overlap before classification is a necessary step to be targeted. To achieve this goal, a dissimilarity space is initially created. As a result of the definition of the new space, the class overlap between objects (seismic samples) is reduced and hence the classification can be done reliably. This strategy causes an increase in the accuracy of classification, and a more trustworthy lithofacies analysis is attained. For applying this method, 3D seismic data from an oil field in Iran were selected and the results obtained by a support vector classifier (SVC) in dissimilarity space are presented, discussed and compared with the SVC applied in conventional feature space.

  17. On horizontal resolution for seismic acquisition geometries in complex 3D media

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Fu, Li-Yun

    2014-09-01

    Spatial sampling has a crucial influence on the horizontal resolution of seismic imaging, but how to quantify the influence is still controversial especially in complex media. Most of the studies on horizontal resolution focus on the measurement of wavelet widths for seismic migration, but neglect to evaluate the effect of side-lobe perturbations on spatial resolution. The side-lobe effect, as a migration noise, is important for seismic imaging in complex media. In this article, with focal beam analysis, we define two parameters to represent the horizontal resolution of an acquisition geometry: the width of the main lobe (WML) along the inline and crossline directions and the ratio of the main-lobe amplitude to the total amplitude (RMT) in a focal beam. We provide examples of typical acquisition geometries to show how spatial sampling affects the horizontal resolution, measured in terms of WML and RMT values. WML defines the horizontal resolution to image the target, whereas RMT describes the clarity of the imaging. Migration noise reduces with increasing RMT, indirectly improving both the vertical and horizontal resolutions of seismic imaging. Case studies of seismic migration with 3D seismic data from an oil field of China, demonstrate how the acquisition geometries with different WML and RMT values influence the performance of seismic imaging. Prior WML and RMT analyses to predict the quality of acquired datasets can optimize acquisition geometries before the implementation of seismic acquisition.

  18. P-Cable: New High-Resolution 3D Seismic Acquisition Technology

    NASA Astrophysics Data System (ADS)

    Planke, Sverre; Berndt, Christian; Mienert, Jürgen; Bünz, Stefan; Eriksen, Frode N.; Eriksen, Ola K.

    2010-05-01

    We have developed a new cost-efficient technology for acquisition of high-resolution 3D seismic data: the P-Cable system. This technology is very well suited for deep water exploration, site surveys, and studies of shallow gas and fluid migration associated with gas hydrates or leaking reservoirs. It delivers unparalleled 3D seismic images of subsurface sediment architectures. The P-Cable system consists of a seismic cable towed perpendicular to a vessel's steaming direction. This configuration allows us to image an up to 150 m wide swath of the sub-surface for each sail line. Conventional 3D seismic technology relies on several very long streamers (up to 10 km long streamers are common), large sources, and costly operations. In contrast, the P-Cable system is light-weight and fast to deploy from small vessels. Only a small source is required as the system is made for relatively shallow imaging, typically above the first water-bottom multiple. The P-Cable system is particularly useful for acquisition of small 3D cubes, 10-50 km2, in focus areas, rather than extensive mapping of large regions. The rapid deployment and recovery of the system makes it possible to acquire several small cubes (10 to 30 km2) with high-resolution (50-250 Hz) seismic data in during one cruise. The first development of the P-Cable system was a cooperative project achieved by Volcanic Basin Petroleum Research (VBPR), University of Tromsø, National Oceanography Centre, Southampton, and industry partners. Field trials using a 12-streamer system were conducted on sites with active fluid-leakage systems on the Norwegian-Barents-Svalbard margin, the Gulf of Cadiz, and the Mediterranean. The second phase of the development introduced digital streamers. The new P-Cable2 system also includes integrated tow and cross cables for power and data transmission and improved doors to spread the larger cross cable. This digital system has been successfully used during six cruises by the University of Troms

  19. Automated modeling of RNA 3D structure.

    PubMed

    Rother, Kristian; Rother, Magdalena; Skiba, Pawel; Bujnicki, Janusz M

    2014-01-01

    This chapter gives an overview over the current methods for automated modeling of RNA structures, with emphasis on template-based methods. The currently used approaches to RNA modeling are presented with a side view on the protein world, where many similar ideas have been used. Two main programs for automated template-based modeling are presented: ModeRNA assembling structures from fragments and MacroMoleculeBuilder performing a simulation to satisfy spatial restraints. Both approaches have in common that they require an alignment of the target sequence to a known RNA structure that is used as a modeling template. As a way to find promising template structures and to align the target and template sequences, we propose a pipeline combining the ParAlign and Infernal programs on RNA family data from Rfam. We also briefly summarize template-free methods for RNA 3D structure prediction. Typically, RNA structures generated by automated modeling methods require local or global optimization. Thus, we also discuss methods that can be used for local or global refinement of RNA structures.

  20. New 3D seismicity maps using chromo-stereoscopy with two alternative freewares

    NASA Astrophysics Data System (ADS)

    Okamoto, Y.

    2011-12-01

    Seismicity maps play a key role in an introduction of geosciences studies or outreach programs. Various techniques are used in order to show earthquakes in a three dimensional field. To use "chromo-stereoscopy" is our simple and easier-making solution. The Chroma Depth 3D Glasses are employed for this purpose. The glasses consist of two transparent blazed grating films covered with a paper holder and cost a little (1 US$). Looking through these glasses, the colored chart turns into three dimensional perspective due to the mechanism that the color codes make a depth dimension with dispersion. We use two complementary freewares to make maps, the GMT (Generic Mapping Tools, Wessel and Smith.1988) and the POV-Ray (Persistence of Vision Pty. Ltd. 2004). The two softwares have their own advantages; the GMT is specialized for map making with simple scripts, while the POV-Ray produces realistic 3D rendering images with more complicated scripts. The earthquakes are plotted with the rainbow color codes depending on their depths in a black background as printed or PC images. Therefore, the red colored shallow earthquakes are float in front and blue colored ones sink deeper. This effect is so amazing that the students who first wear these glasses are strongly moved and fascinated with this simple mechanism. The data used here are from JMA seismicity catalogue and USGS (ANSS) catalogue. The POV-Ray version needs coastline data, so we got them from the Coastline Extractor (NGDC) web site. Also, the POR-Ray has no function to draw lines in three dimensions, so we had to make some trials for showing them in relief. The main target of our map is "the Wadati-Beniof zone", in which the sub-ducting oceanic plate surface is fringed by deeper earthquakes colored yellow, green to blue. The active volcanic regions such as the Hawaii islands or the active fault regions such as the San Andreas Fault are also effective targets of our method. However, since their shallow complicated seismic

  1. 3D Seismic Experimentation and Advanced Processing/Inversion Development for Investigations of the Shallow Subsurface

    SciTech Connect

    Levander, Alan Richard; Zelt, Colin A.

    2015-03-17

    The work plan for this project was to develop and apply advanced seismic reflection and wide-angle processing and inversion techniques to high resolution seismic data for the shallow subsurface to seismically characterize the shallow subsurface at hazardous waste sites as an aid to containment and cleanup activities. We proposed to continue work on seismic data that we had already acquired under a previous DoE grant, as well as to acquire additional new datasets for analysis. The project successfully developed and/or implemented the use of 3D reflection seismology algorithms, waveform tomography and finite-frequency tomography using compressional and shear waves for high resolution characterization of the shallow subsurface at two waste sites. These two sites have markedly different near-surface structures, groundwater flow patterns, and hazardous waste problems. This is documented in the list of refereed documents, conference proceedings, and Rice graduate theses, listed below.

  2. The 3D crustal structure of Northeastern Tibetan area from seismic tomography

    NASA Astrophysics Data System (ADS)

    Sun, Anhui

    2015-04-01

    The Northeastern Tibetan region is located in the border area of three sub-plates in China, i.e. the Tibetan plateau, North China block and Xinjiang block. Effected simultaneously by the extrusion driven by the India-Eurasia plat collision and the blockage of the Ordos basin, this area has complex geology, strong tectonics activities and suffered from several large historic earthquakes, such as the Haiyuan earthquake (M8.6) in 1920, the Gulang earthquake (M8.0) in 1927. To enhance our understanding of the crustal structure and the interaction between different tectonic blocks of this region, we conduct a three-dimensional (3D) tomographic study by using the arrival time date recorded by regional seismic network. We used 101101 P and 103313 S wave arrival times from 11650 local earthquakes during 1970 to 2013 recorded by 154 permanent seismic stations of the local Seismic Network, installed over five provinces in China, i.e. Gansu, Ningxia, Qinghai, Shanxi, Neimenggu. We first established a 1D primary crustal model from LITHO1.0, an updated crust and lithospheric model of the Earth by weighted averaging. To better performer ray tracing, our inversion involved three discontinuities (including the Moho) with depth variation over the mantle derived from LITHO1.0. Detailed three-dimensional seismic velocity (Vp and Vs) structures of the crust of the Northeastern Tibetan are determined with a horizontal resolution of about 35 km and a depth resolution of 6-20 km. The Poisson's ratio (σ) structure was also estimated after obtained Vp and Vs structures. We detected low-velocity anomalies in the lower crust and relative high-velocity anomalies in the upper crust beneath the Longmenshan faults zone, which are in good agreement with the results of most previous geophysical studies. Our results revealed clear different velocity variation beneath both sides of different tectonic blocks. In addition, we found the correlation between our tomographic result and previous

  3. 3D Modelling of Kizildag Monument

    NASA Astrophysics Data System (ADS)

    Karauguz, Güngör; Kalayci, İbrahim; Öğütcü, Sermet

    2016-10-01

    The most important cultural property that the nations possess is their historical accumulation, and bringing these to light, taking measures to preserve them or at least maintain the continuity of transferring them to next generations by means of recent technic and technology, ought to be the business of present generations. Although, nowadays, intensive documentation and archiving studies are done by means of classical techniques, besides studies towards preserving historical objects, modelling one-to-one or scaled modelling were not possible until recently. Computing devices and the on-going reflection of this, which is acknowledged as digital technology, is widely used in many areas and makes it possible to document and archive historical works. Even virtual forms in quantitative environments can be transferred to next generations in a scaled and one-to-one modelled way. Within this scope, every single artefact categorization belonging to any era or civilization present in our country can be considered in separate study areas. Furthermore, any work or likewise can be evaluated in separate categories. Also, it is possible to construct travelable virtual 3D museums that make it possible to visit these artefacts. Under the auspices of these technologies, it is quite possible to construct single virtual indoor museums or also, at the final stage, a 3D travelable open-air museum, a platform or more precisely, to establish a data system that spreads all over the country on a broad spectrum. With a long-termed, significant and extensive study and a substantial organization, such a data system can be established, which also serves as a serious infrastructure for alternative tourism possibilities. Located beside a stepped altar and right above the Kizildag IV inscription, the offering pot is destructed and rolled away a few meters to the south slope of the mould. Every time visiting these artefacts with our undergraduate students, unfortunately, we observe more

  4. Drill site geohazard identification facilitated by rework of suitable existing 3D seismic data volumes

    SciTech Connect

    Cowlard, A.P.

    1996-12-31

    3D seismic volumes are increasingly being used to assist in the mapping and identification of drilling hazards. A method of reworking the 3D volume, termed the Short Offset method, is proposed which offers the benefit of optimized resolution in the shallow section and therefore provides the interpreter with an enhanced image of the near surface geology. The processing sequence contrasts markedly with conventional 3D processing and involves the inclusion of only near normal incidence traces. Two case histories are described which illustrate the application of the Short Offset method and its robustness even in conditions not conducive to enhancing frequency bandwidth. In summary, Short Offset reprocessing results in a product which offers considerably improved resolution when compared to a conventional 3D volume and far finer areal sampling when compared to a traditional 2D site survey thus providing the industry with a valuable tool for drilling hazard investigation.

  5. How 3D seismic-CAEX combination affected development of N. Frisco City field in Alabama

    SciTech Connect

    Stephenson, M.; Cox, J.; Jones-Fuentes, P. )

    1992-10-26

    This paper reports that by applying the latest in 3D seismic and computer aided exploration and production (CAEX) technology, small and mid-size independents are changing the methods by which fields are discovered and profitably developed. The combination of 3D and CAEX has, in many cases, altered oilfield economics. Nuevo Energy Co.'s North Frisco City development---located in the updip Jurassic Haynesville trend of Southwest Alabama---offers a case in point. The 3D technology employed at North Frisco City produced and accurate, detailed picture of the subsurface. Ultimately it more than doubled the drilling success rate over that of a nearby, closely related field in which 3D was not used.

  6. Characterization of gas hydrate distribution using conventional 3D seismic data in the Pearl River Mouth Basin, South China Sea

    USGS Publications Warehouse

    Wang, Xiujuan; Qiang, Jin; Collett, Timothy S.; Shi, Hesheng; Yang, Shengxiong; Yan, Chengzhi; Li, Yuanping; Wang, Zhenzhen; Chen, Duanxin

    2016-01-01

    A new 3D seismic reflection data volume acquired in 2012 has allowed for the detailed mapping and characterization of gas hydrate distribution in the Pearl River Mouth Basin in the South China Sea. Previous studies of core and logging data showed that gas hydrate occurrence at high concentrations is controlled by the presence of relatively coarse-grained sediment and the upward migration of thermogenic gas from the deeper sediment section into the overlying gas hydrate stability zone (BGHSZ); however, the spatial distribution of the gas hydrate remains poorly defined. We used a constrained sparse spike inversion technique to generate acoustic-impedance images of the hydrate-bearing sedimentary section from the newly acquired 3D seismic data volume. High-amplitude reflections just above the bottom-simulating reflectors (BSRs) were interpreted to be associated with the accumulation of gas hydrate with elevated saturations. Enhanced seismic reflections below the BSRs were interpreted to indicate the presence of free gas. The base of the BGHSZ was established using the occurrence of BSRs. In areas absent of well-developed BSRs, the BGHSZ was calculated from a model using the inverted P-wave velocity and subsurface temperature data. Seismic attributes were also extracted along the BGHSZ that indicate variations reservoir properties and inferred hydrocarbon accumulations at each site. Gas hydrate saturations estimated from the inversion of acoustic impedance of conventional 3D seismic data, along with well-log-derived rock-physics models were also used to estimate gas hydrate saturations. Our analysis determined that the gas hydrate petroleum system varies significantly across the Pearl River Mouth Basin and that variability in sedimentary properties as a product of depositional processes and the upward migration of gas from deeper thermogenic sources control the distribution of gas hydrates in this basin.

  7. 3D Geologic Model of the San Diego Area

    NASA Astrophysics Data System (ADS)

    Danskin, W. R.; Cromwell, G.; Glockhoff, C.; Martin, D.

    2015-12-01

    Prior geologic studies of the San Diego area, including northern Baja California, Mexico, focused on site investigations, characterization of rock formations, or earthquake hazards. No comprehensive, quantitative model characterizing the three-dimensional (3D) geology of the entire area has been developed. The lack of such a model limits understanding of large-scale processes, such as development of ancient landforms, and groundwater movement and availability. To evaluate these regional processes, the United States Geological Survey (USGS) conducted a study to better understand the geologic structure of the San Diego area. A cornerstone of this study is the installation and analysis of 77 wells at 12 multiple-depth monitoring-well sites. Geologic information from these wells was combined with lithologic data from 81 oil exploration wells and municipal and private water wells, gravity and seismic interpretations, and paleontological interpretations. These data were analyzed in conjunction with geologic maps and digital elevation models to develop a 3D geologic model of the San Diego area, in particular of the San Diego embayment. Existing interpretations of regional surficial geology, faulting, and tectonic history provided the framework for this model, which was refined by independent evaluation of subsurface geology. Geologic formations were simplified into five sedimentary units (Quaternary, Plio-Pleistocene, Oligocene, Eocene and Cretaceous ages), and one basal crystalline unit (primarily Cretaceous and Jurassic). Complex fault systems are represented in the model by ten fault strands that maintain overall displacement. The 3D geologic model corroborates existing geologic concepts of the San Diego area, refines the extent of subsurface geology, and allows users to holistically evaluate subsurface structures and regional hydrogeology.

  8. High-resolution 3-D P wave attenuation structure of the New Madrid Seismic Zone using local earthquake tomography

    NASA Astrophysics Data System (ADS)

    Bisrat, Shishay T.; DeShon, Heather R.; Pesicek, Jeremy; Thurber, Clifford

    2014-01-01

    A three-dimensional (3-D), high-resolution P wave seismic attenuation model for the New Madrid Seismic Zone (NMSZ) is determined using P wave path attenuation (t*) values of small-magnitude earthquakes (MD < 3.9). Events were recorded at 89 broadband and short-period seismometers of the Cooperative New Madrid Seismic Zone Network and 40 short-period seismometers of the Portable Array for Numerical Data Acquisition experiment. The amplitude spectra of all the earthquakes are simultaneously inverted for source, path (t*), and site parameters. The t* values are inverted for QP using local earthquake tomography methods and a known 3-D P wave velocity model for the region. The four major seismicity arms of the NMSZ exhibit reduced QP (higher attenuation) than the surrounding crust. The highest attenuation anomalies coincide with areas of previously reported high swarm activity attributed to fluid-rich fractures along the southeast extension of the Reelfoot fault. The QP results are consistent with previous attenuation studies in the region, which showed that active fault zones and fractured crust in the NMSZ are highly attenuating.

  9. 3-D physical models of amitosis (cytokinesis).

    PubMed

    Cheng, Kang; Zou, Changhua

    2005-01-01

    Based on Newton's laws, extended Coulomb's law and published biological data, we develop our 3-D physical models of natural and normal amitosis (cytokinesis), for prokaryotes (bacterial cells) in M phase. We propose following hypotheses: Chromosome rings exclusion: No normally and naturally replicated chromosome rings (RCR) can occupy the same prokaryote, a bacterial cell. The RCR produce spontaneous and strong electromagnetic fields (EMF), that can be alternated environmentally, in protoplasm and cortex. The EMF is approximately a repulsive quasi-static electric (slowly variant and mostly electric) field (EF). The EF forces between the RCR are strong enough, and orderly accumulate contractile proteins that divide the procaryotes in the cell cortex of division plane or directly split the cell compartment envelope longitudinally. The radial component of the EF forces could also make furrows or cleavages of procaryotes. The EF distribution controls the protoplasm partition and completes the amitosis (cytokinesis). After the cytokinesis, the spontaneous and strong EF disappear because the net charge accumulation becomes weak, in the protoplasm. The exclusion is because the two sets of informative objects (RCR) have identical DNA codes information and they are electro magnetically identical, therefore they repulse from each other. We also compare divisions among eukaryotes, prokaryotes, mitochondria and chloroplasts and propose our hypothesis: The principles of our models are applied to divisions of mitochondria and chloroplasts of eucaryotes too because these division mechanisms are closer than others in a view of physics. Though we develop our model using 1 division plane (i.e., 1 cell is divided into 2 cells) as an example, the principle of our model is applied to the cases with multiple division planes (i.e., 1 cell is divided into multiple cells) too.

  10. Comparative velocity structure of active Hawaiian volcanoes from 3-D onshore-offshore seismic tomography

    USGS Publications Warehouse

    Park, J.; Morgan, J.K.; Zelt, C.A.; Okubo, P.G.; Peters, L.; Benesh, N.

    2007-01-01

    We present a 3-D P-wave velocity model of the combined subaerial and submarine portions of the southeastern part of the Island of Hawaii, based on first-arrival seismic tomography of marine airgun shots recorded by the onland seismic network. Our model shows that high-velocity materials (6.5-7.0??km/s) lie beneath Kilauea's summit, Koae fault zone, and the upper Southwest Rift Zone (SWRZ) and upper and middle East Rift Zone (ERZ), indicative of magma cumulates within the volcanic edifice. A separate high-velocity body of 6.5-6.9??km/s within Kilauea's lower ERZ and upper Puna Ridge suggests a distinct body of magma cumulates, possibly connected to the summit magma cumulates at depth. The two cumulate bodies within Kilauea's ERZ may have undergone separate ductile flow seaward, influencing the submarine morphology of Kilauea's south flank. Low velocities (5.0-6.3??km/s) seaward of Kilauea's Hilina fault zone, and along Mauna Loa's seaward facing Kao'iki fault zone, are attributed to thick piles of volcaniclastic sediments deposited on the submarine flanks. Loihi seamount shows high-velocity anomalies beneath the summit and along the rift zones, similar to the interpreted magma cumulates below Mauna Loa and Kilauea volcanoes, and a low-velocity anomaly beneath the oceanic crust, probably indicative of melt within the upper mantle. Around Kilauea's submarine flank, a high-velocity anomaly beneath the outer bench suggests the presence of an ancient seamount that may obstruct outward spreading of the flank. Mauna Loa's southeast flank is also marked by a large, anomalously high-velocity feature (7.0-7.4??km/s), interpreted to define an inactive, buried volcanic rift zone, which might provide a new explanation for the westward migration of Mauna Loa's current SWRZ and the growth of Kilauea's SWRZ. ?? 2007 Elsevier B.V. All rights reserved.

  11. Combining sequence stratigraphy with 3-D seismic imaging in low-accommodation basins

    SciTech Connect

    Hardage, B.A.; Carr, D.L.; Simmons, J.L. Jr.

    1995-12-31

    Pennsylvania-age rocks in several areas of the Midcontinent of the United States were deposited in low-accommodation basinal settings, that is, in basinal areas where only modest verticle reliefs could accept the sediment influx. Many thin Pennsylvanian sequences in these low-accommodation environments exhibit severe lateral heterogeneity because they have been extensively reworked by repeated transgressions and regressions of a fluctuating sea. Consequently, the distinctive geometries of relic depositional features (such as meandering channels) tend to be distorted or even totally destroyed, as compared with how such geometries appear in high-accommodation basins where depositional topography, once buried, is rarely exposed to destructive processes. Our objectives are to show examples of 3-D seismic images of several depositional topographies in a moderate- to low-accommodation basin and to explain how these thin sequences can be identified in well control and interpreted in 3-D seismic data volumes.

  12. Multi-view and 3D deformable part models.

    PubMed

    Pepik, Bojan; Stark, Michael; Gehler, Peter; Schiele, Bernt

    2015-11-01

    As objects are inherently 3D, they have been modeled in 3D in the early days of computer vision. Due to the ambiguities arising from mapping 2D features to 3D models, 3D object representations have been neglected and 2D feature-based models are the predominant paradigm in object detection nowadays. While such models have achieved outstanding bounding box detection performance, they come with limited expressiveness, as they are clearly limited in their capability of reasoning about 3D shape or viewpoints. In this work, we bring the worlds of 3D and 2D object representations closer, by building an object detector which leverages the expressive power of 3D object representations while at the same time can be robustly matched to image evidence. To that end, we gradually extend the successful deformable part model [1] to include viewpoint information and part-level 3D geometry information, resulting in several different models with different level of expressiveness. We end up with a 3D object model, consisting of multiple object parts represented in 3D and a continuous appearance model. We experimentally verify that our models, while providing richer object hypotheses than the 2D object models, provide consistently better joint object localization and viewpoint estimation than the state-of-the-art multi-view and 3D object detectors on various benchmarks (KITTI [2] , 3D object classes [3] , Pascal3D+ [4] , Pascal VOC 2007 [5] , EPFL multi-view cars[6] ).

  13. Fluid Flow Processes Study: from a 3D seismic data set in the Pointer Ridge offshore SW Taiwan

    NASA Astrophysics Data System (ADS)

    Han, Wei-Chung; Liu, Char-Shine; Chen, Liwen; Chi, Wu-Cheng; Lin, Che-Chuan

    2016-04-01

    This study analyzes a 3D seismic cube in the Pointer Ridge for understanding the fluid flow processes in subsurface. Pointer Ridge is a ridge situated on the passive China continental margin and is suggested as a potential prospect for future gas hydrate development. High methane flux rate, active gas venting and seismic chimneys have been observed in this area, which are direct evidences for active ongoing fluid migration processes. To find the possible fluid conduits and to understand how the fluids have migrated along those conduits, we firstly identify the structural and sedimentary features from this 3D seismic cube in our study area. Secondly, seismic attribute analyses are carried out for detecting fluid conduits and evaluating the contribution of recognized faults/fractures for fluid flow, respectively. Finally, we propose conceptual models to illustrate how fluids have migrated along those conduits to the seafloor and how those conduits have developed. The results show: 1) a major NE-SW striking normal fault (PR Fault) separates a depositional field on the hanging wall and a erosional field on the footwall; 2) the PR Fault zone itself and the chimneys in its footwall act as main conduits for focused fluid flow migrating to the seafloor; 3) the development of the chimneys in the Pointer Ridge area are highly controlled by the erosion and deposition processes. Since the ongoing fluid flow processes will increase the seafloor instabilities and the Pointer Ridge is a gas hydrate leaking site, our results could provide useful information for further risk evaluation.

  14. Preliminary results of the CRISP 3D seismic experiment, offshore Costa Rica

    NASA Astrophysics Data System (ADS)

    Bangs, N. L.; McIntosh, K. D.; Silver, E. A.; Ranero, C. R.; Kluesner, J. W.; von Huene, R.; Cavanaugh, S.; Graf, S.; Cameselle, A. L.; Baracco, A. M.; Nuñez, E.

    2011-12-01

    In April and May of 2011, we acquired a new 3D seismic reflection data volume offshore Costa Rica, northwest of the Osa Peninsula. The goal of the survey was to examine the crustal structure and deformation history of this collision zone, and to clearly image the plate-boundary fault from the trench and into the seismogenic zone. These data will also help locate a deep site for riser drilling as part of the CRISP drilling program. The 3D survey covered 55 km across the upper shelf and slope, and into the trench. It extended 11 km along strike for a total survey area of 11 x 55 km. These data were acquired with the R/V Langseth using a 3300 cubic inch source shot every 50 m. We recorded the data on four 6-km-long, 468-channel streamers with 150m separation. We have preliminary results from processing 2D seismic lines extracted from the 3D volume, and from initial 3D volume processing. In the preliminary images we can trace strong seismic reflections from the plate-boundary fault down to 3 s two-way travel time (approx. 5 km depth) below the seafloor and 26 km landward from the trench. The plate-boundary fault reflection amplitudes decrease substantially with depth and are difficult to depict on these preliminary profiles. The upper plate structure shows numerous faults, many extending down to the plate-interface, and intense folding and faulting of the slope cover sequences. Currently these data are being processed by the Spanish oil company, Repsol, and should reveal far more detail with complete 3D processing.

  15. Characterization of a landslide geometry using 3D seismic refraction traveltime tomography: The La Valette landslide case history

    NASA Astrophysics Data System (ADS)

    Samyn, K.; Travelletti, J.; Bitri, A.; Grandjean, G.; Malet, J.-P.

    2012-11-01

    The geometry of the bedrock, internal layers and shear surfaces/bands controls the deformation pattern and the mechanisms of landslides. A challenge to progress in the forecast of landslide acceleration in terms of early-warning is therefore to characterize the 3D geometry of the unstable mass at a high level of spatial resolution, both in the horizontal and vertical directions, by integrating information from different surveying techniques. For such characterization, seismic investigations are potentially of a great interest. In the case of complex structures, the measure and the processing of seismic data need to be performed in 3D. The objective of this work is to present the development of a 3D extension of a seismic refraction traveltime tomography technique based on a Simultaneous Iterative Reconstruction Technique (SIRT). First the processing algorithm is detailed and its performance is discussed, and second an application to the La Valette complex landslide is presented. Inversion of first-arrival traveltimes produces a 3D tomogram that underlines the presence of many areas characterized by low P-wave velocity of 500-1800 m.s- 1. These low P-wave velocity structures result from the presence of reworked blocks, surficial cracks and in-depth fracture zones. These structures seem to extend to around 25 m in depth over a 80 × 130 m area. Based on borehole geotechnical data and previous geophysical investigations, an interface corresponding to an internal slip surface can be suspected near the isovalue of 1200 m.s- 1 at a depth of - 10 to - 15 m. The stable substratum is characterized by higher values of P-wave velocity of 1800-3000 m.s- 1. The features identified in the 3D tomogram allow to better (1) delineate the boundary between the landslide and the surrounding stable slopes, and (2) understand the morphological structures within the landslide at a hectometric scale. The integration of the 3D seismic tomography interpretation to previous geophysical

  16. 3D-GNOME: an integrated web service for structural modeling of the 3D genome.

    PubMed

    Szalaj, Przemyslaw; Michalski, Paul J; Wróblewski, Przemysław; Tang, Zhonghui; Kadlof, Michal; Mazzocco, Giovanni; Ruan, Yijun; Plewczynski, Dariusz

    2016-07-08

    Recent advances in high-throughput chromosome conformation capture (3C) technology, such as Hi-C and ChIA-PET, have demonstrated the importance of 3D genome organization in development, cell differentiation and transcriptional regulation. There is now a widespread need for computational tools to generate and analyze 3D structural models from 3C data. Here we introduce our 3D GeNOme Modeling Engine (3D-GNOME), a web service which generates 3D structures from 3C data and provides tools to visually inspect and annotate the resulting structures, in addition to a variety of statistical plots and heatmaps which characterize the selected genomic region. Users submit a bedpe (paired-end BED format) file containing the locations and strengths of long range contact points, and 3D-GNOME simulates the structure and provides a convenient user interface for further analysis. Alternatively, a user may generate structures using published ChIA-PET data for the GM12878 cell line by simply specifying a genomic region of interest. 3D-GNOME is freely available at http://3dgnome.cent.uw.edu.pl/.

  17. 3D-GNOME: an integrated web service for structural modeling of the 3D genome

    PubMed Central

    Szalaj, Przemyslaw; Michalski, Paul J.; Wróblewski, Przemysław; Tang, Zhonghui; Kadlof, Michal; Mazzocco, Giovanni; Ruan, Yijun; Plewczynski, Dariusz

    2016-01-01

    Recent advances in high-throughput chromosome conformation capture (3C) technology, such as Hi-C and ChIA-PET, have demonstrated the importance of 3D genome organization in development, cell differentiation and transcriptional regulation. There is now a widespread need for computational tools to generate and analyze 3D structural models from 3C data. Here we introduce our 3D GeNOme Modeling Engine (3D-GNOME), a web service which generates 3D structures from 3C data and provides tools to visually inspect and annotate the resulting structures, in addition to a variety of statistical plots and heatmaps which characterize the selected genomic region. Users submit a bedpe (paired-end BED format) file containing the locations and strengths of long range contact points, and 3D-GNOME simulates the structure and provides a convenient user interface for further analysis. Alternatively, a user may generate structures using published ChIA-PET data for the GM12878 cell line by simply specifying a genomic region of interest. 3D-GNOME is freely available at http://3dgnome.cent.uw.edu.pl/. PMID:27185892

  18. Sequence stratigraphy and 3-D seismic imaging in low-accommodation basins

    SciTech Connect

    Hardage, B.A.; Carr, D.L.; Hamilton, D.S.; Simmons, J.L. Jr. )

    1996-01-01

    Pennsylvanian-age rocks in several areas of the Midcontinent of the United States were deposited in low-accommodation basinal settings. Many sequences in these low-accommodation environments exhibit severe lateral heterogeneity because they have been extensively reworked by repeated transgressions and regressions. Consequently, the distinctive geometries of relic depositional features tend to be distorted or totally destroyed, in contrast to such geometries in high-accommodation basins where depositional topography, once buried, is rarely exposed to erosional processes. Our objective is to show how these thin and obscure low-accommodation sequences can be identified in well control and interpreted in 3-D seismic data volumes. Numerous, deep-rooted karst-collapse zones affected the areal continuity of many sequences in some Midcontinent basins. We combine sequence stratigraphy with 3-D seismic imaging to document that many of these karst-collapse zones originate at deep Ellenburger ( ) levels and then extend vertically for a distance of 2,000 ft (600 m) or more into Pennsylvanian-age rocks. We also offer evidence that properly chosen seismic attributes, calculated in thin, accurately defined seismic time windows that correspond to log-defined sequences, show compartmented reservoir facies in low-accommodation basins.

  19. Sequence stratigraphy and 3-D seismic imaging in low-accommodation basins

    SciTech Connect

    Hardage, B.A.; Carr, D.L.; Hamilton, D.S.; Simmons, J.L. Jr.

    1996-12-31

    Pennsylvanian-age rocks in several areas of the Midcontinent of the United States were deposited in low-accommodation basinal settings. Many sequences in these low-accommodation environments exhibit severe lateral heterogeneity because they have been extensively reworked by repeated transgressions and regressions. Consequently, the distinctive geometries of relic depositional features tend to be distorted or totally destroyed, in contrast to such geometries in high-accommodation basins where depositional topography, once buried, is rarely exposed to erosional processes. Our objective is to show how these thin and obscure low-accommodation sequences can be identified in well control and interpreted in 3-D seismic data volumes. Numerous, deep-rooted karst-collapse zones affected the areal continuity of many sequences in some Midcontinent basins. We combine sequence stratigraphy with 3-D seismic imaging to document that many of these karst-collapse zones originate at deep Ellenburger (?) levels and then extend vertically for a distance of 2,000 ft (600 m) or more into Pennsylvanian-age rocks. We also offer evidence that properly chosen seismic attributes, calculated in thin, accurately defined seismic time windows that correspond to log-defined sequences, show compartmented reservoir facies in low-accommodation basins.

  20. TOMO3D: 3-D joint refraction and reflection traveltime tomography parallel code for active-source seismic data—synthetic test

    NASA Astrophysics Data System (ADS)

    Meléndez, A.; Korenaga, J.; Sallarès, V.; Miniussi, A.; Ranero, C. R.

    2015-10-01

    We present a new 3-D traveltime tomography code (TOMO3D) for the modelling of active-source seismic data that uses the arrival times of both refracted and reflected seismic phases to derive the velocity distribution and the geometry of reflecting boundaries in the subsurface. This code is based on its popular 2-D version TOMO2D from which it inherited the methods to solve the forward and inverse problems. The traveltime calculations are done using a hybrid ray-tracing technique combining the graph and bending methods. The LSQR algorithm is used to perform the iterative regularized inversion to improve the initial velocity and depth models. In order to cope with an increased computational demand due to the incorporation of the third dimension, the forward problem solver, which takes most of the run time (˜90 per cent in the test presented here), has been parallelized with a combination of multi-processing and message passing interface standards. This parallelization distributes the ray-tracing and traveltime calculations among available computational resources. The code's performance is illustrated with a realistic synthetic example, including a checkerboard anomaly and two reflectors, which simulates the geometry of a subduction zone. The code is designed to invert for a single reflector at a time. A data-driven layer-stripping strategy is proposed for cases involving multiple reflectors, and it is tested for the successive inversion of the two reflectors. Layers are bound by consecutive reflectors, and an initial velocity model for each inversion step incorporates the results from previous steps. This strategy poses simpler inversion problems at each step, allowing the recovery of strong velocity discontinuities that would otherwise be smoothened.

  1. 3D fast wavelet network model-assisted 3D face recognition

    NASA Astrophysics Data System (ADS)

    Said, Salwa; Jemai, Olfa; Zaied, Mourad; Ben Amar, Chokri

    2015-12-01

    In last years, the emergence of 3D shape in face recognition is due to its robustness to pose and illumination changes. These attractive benefits are not all the challenges to achieve satisfactory recognition rate. Other challenges such as facial expressions and computing time of matching algorithms remain to be explored. In this context, we propose our 3D face recognition approach using 3D wavelet networks. Our approach contains two stages: learning stage and recognition stage. For the training we propose a novel algorithm based on 3D fast wavelet transform. From 3D coordinates of the face (x,y,z), we proceed to voxelization to get a 3D volume which will be decomposed by 3D fast wavelet transform and modeled after that with a wavelet network, then their associated weights are considered as vector features to represent each training face . For the recognition stage, an unknown identity face is projected on all the training WN to obtain a new vector features after every projection. A similarity score is computed between the old and the obtained vector features. To show the efficiency of our approach, experimental results were performed on all the FRGC v.2 benchmark.

  2. Initial Look at 3d Seismic Data Acquired Over the Galicia Margin

    NASA Astrophysics Data System (ADS)

    Sawyer, D. S.; Reston, T. J.; Shillington, D. J.; Minshull, T. A.; Klaeschen, D.; Morgan, J. K.

    2013-12-01

    In June thru September, 2013, a 3D reflection and long offset seismic experiment was conducted at the Galicia rifted margin by investigators from the US, UK, Germany, and Spain. The 3D multichannel experiment covered 64 km by 20 km (1280 km2), using the RV Marcus Langseth. Four streamers 6 km long were deployed at 12.5 m hydrophone channel spacing. The streamers were 200 m apart. Two airgun arrays, each 3300 cu in, were fired alternately every 37.5 m, to collectively yield a 400 m wide sail line consisting of 8 CMP lines at 50 m spacing. The long offset seismic experiment included 72 short period OBS's deployed below the 3D reflection survey box. Most of the instruments recorded all the shots from the airgun array shots. A few of the instruments were deployed twice, once to densify the instruments on a single profile and then to be moved into the full array. Finally, 6 of the OBS's were deployed on a profile extending 90 km to the west of the 3D box, in order to use combined MCS and OBS data to locate the boundary between the oceanic crust and exhumed upper mantle. The 3D seismic box covered a variety of geologic features including the Peridotite Ridge (PR) associated with the exhumation of upper mantle rocks to the seafloor, the S reflector interpreted to be a low-angle detachment fault formed late in the rifting process, and a number of rotated fault block basins and ranges containing pre- and syn-rift sediments. Initial observations, based only on 2D seismic dip lines (albeit 400 m apart), show the along strike variation of the PR: ~1050 m higher than adjacent basement in the South of the 3D box and much increased in size, ~2200 m high in the North. Some cross-sections of the PR show apparent internal structure that may help identify the emplacement mechanism of the feature and its relationship with the boundary between rifted continental crust blocks and exhumed upper mantle rocks. To the immediate East and West of the PR there are strong negative

  3. A 3D Seismic Case: Shooting around a CCS Drill Site

    NASA Astrophysics Data System (ADS)

    Wang, C.

    2013-12-01

    The reduction of carbon dioxide emission to lessen the global warming has become an important international issue in recent years. The CCS technique (Carbon-dioxide Capture and Storage) is among the most recommended methods. The capture of CO2 during its manufacturing process in the electric power plant and storing in the adjacent area is considered to be an economical and feasible choice. This research uses the 2D and 3D high-resolution seismic reflection method to investigate possible CCS sites along the coast in Taiwan. The site is near an electric power plant and is planned to be a CCS experiment laboratory. The main objective is to detect the proper geologic structure and to prepare the baseline data for the future CO2 monitoring. The size of the high-resolution method applied in this study is much smaller than that used in the oil exploration. The obtained high quality and high resolution data can resolve very detailed structures. The survey parameters in 2D are 4m interval, 240 channels. The bin size in 3D seismic is 8m x 4m, 288 channels. Both 2D and 3D used the Minivibe as a source with 40Hz geophones, and having an average of 30 folds. The 3D seismic survey was conducted around the planned drill site. A surrounding type of 3D data acquisition was taken with sources at outside and receivers at the center. Such a deployment design is quite suitable for the drill site investigation. The structural layer as thin as 4m is able to be detected even under a depth of 3000m. Such a high resolution allows us not only to estimate the structure, but also able to monitor the migration of CO 2 after storage. The results of seismic survey after comparing with a nearby borehole data show that : 1) the caprock is Chinshui shale which is at a depth of 880m to 1000m with a thickness about 120m, 2) the Nanchuang formation and Kueichulin formation with high porosity can be proper reservoir layers which are located at the depth between 1000m to 1700m. In conclusion, this site

  4. A 3-D shape model of Interamnia

    NASA Astrophysics Data System (ADS)

    Sato, Isao

    2015-08-01

    A 3-D shape model of the sixth largest of the main belt asteroids, (704) Interamnia, is presented. The model is reproduced from its two stellar occultation observations and six lightcurves between 1969 and 2011. The first stellar occultation was the occultation of TYC 234500183 on 1996 December 17 observed from 13 sites in the USA. An elliptical cross section of (344.6±9.6km)×(306.2±9.1km), for position angle P=73.4±12.5 was fitted. The lightcurve around the occultation shows that the peak-to-peak amplitude was 0.04 mag. and the occultation phase was just before the minimum. The second stellar occultation was the occultation of HIP 036189 on 2003 March 23 observed from 39 sites in Japan and Hawaii. An elliptical cross section of (349.8±0.9km)×(303.7±1.7km), for position angle P=86.0±1.1 was fitted. A companion of 8.5 mag. of the occulted star was discovered whose separation is 12±2 mas (milli-arcseconds), P=148±11 . A combined analysis of rotational lightcurves and occultation chords can return more information than can be obtained with either technique alone. From follow-up photometric observations of the asteroid between 2003 and 2011, its rotation period is determined to be 8.728967167±0.00000007 hours, which is accurate enough to fix the rotation phases at other occultation events. The derived north pole is λ2000=259±8, β2000=-50±5 (retrograde rotation); the lengths of the three principal axes are 2a=361.8±2.8km, 2b=324.4±5.0km, 2c=297.3±3.5km, and the mean diameter is D=326.8±3.0km. Supposing the mass of Interamnia as (3.5±0.9)×10-11 solar masses, the density is then ρ=3.8±1.0 g cm-3.

  5. Anatomy-based 3D skeleton extraction from femur model.

    PubMed

    Gharenazifam, Mina; Arbabi, Ehsan

    2014-11-01

    Using 3D models of bones can highly improve accuracy and reliability of orthopaedic evaluation. However, it may impose excessive computational load. This article proposes a fully automatic method for extracting a compact model of the femur from its 3D model. The proposed method works by extracting a 3D skeleton based on the clinical parameters of the femur. Therefore, in addition to summarizing a 3D model of the bone, the extracted skeleton would preserve important clinical and anatomical information. The proposed method has been applied on 3D models of 10 femurs and the results have been evaluated for different resolutions of data.

  6. Fast 3D elastic micro-seismic source location using new GPU features

    NASA Astrophysics Data System (ADS)

    Xue, Qingfeng; Wang, Yibo; Chang, Xu

    2016-12-01

    In this paper, we describe new GPU features and their applications in passive seismic - micro-seismic location. Locating micro-seismic events is quite important in seismic exploration, especially when searching for unconventional oil and gas resources. Different from the traditional ray-based methods, the wave equation method, such as the method we use in our paper, has a remarkable advantage in adapting to low signal-to-noise ratio conditions and does not need a person to select the data. However, because it has a conspicuous deficiency due to its computation cost, these methods are not widely used in industrial fields. To make the method useful, we implement imaging-like wave equation micro-seismic location in a 3D elastic media and use GPU to accelerate our algorithm. We also introduce some new GPU features into the implementation to solve the data transfer and GPU utilization problems. Numerical and field data experiments show that our method can achieve a more than 30% performance improvement in GPU implementation just by using these new features.

  7. Enhanced imaging of CO2 at the Ketzin storage site: Inversion of 3D time-lapse seismic data

    NASA Astrophysics Data System (ADS)

    Gil, M.; Götz, J.; Ivanova, A.; Juhlin, C.; Krawczyk, C. M.; Lüth, S.; Yang, C.

    2012-04-01

    The Ketzin test site, located near Berlin, is Europe's longest-operating on-shore CO2 storage site. As of December 2011, more than 56,000 tons of food grade CO2 has been injected since June 2008 in an anticlinal structure of the Northeast German Basin. The target reservoir consists of porous, brine bearing sandstone units of the Upper Triassic Stuttgart Formation at approximately 630 to 650 m depth. In order to enhance the understanding of the structural geometry of the site and to investigate the extension of the CO2-plume, several geophysical monitoring methods are being applied at Ketzin, among these are active seismic measurements, geoelectrics and borehole measurements. Among the various seismic techniques (e.g. 2D reflection surveys, crosshole tomography, Vertical Seismic Profiling, 2D- and 3D-Moving Source Profiling) employed at this pilot site, 3D time-lapse reflection surveys are an important component. The baseline 3D survey was acquired in 2005 and the first repeat measurements were performed in 2009 after injection of about 22,000 tons of CO2. The second repeat survey is planned to be carried out in fall 2012. These measurements allow the time-lapse signature of the injected CO2 to be imaged. The time-lapse amplitude variation attributed to the injected CO2 in the reservoir matches, considering detection limits of seismic surface measurements, the expected distribution of the CO2 plume derived from reservoir simulations. Previous attempts towards a quantitative interpretation were based on integrative considerations of different types of geophysical measurements using strict assumptions and characterized by large error bars. In order to increase the resolution and reliability of the data and to improve estimation of rock properties and especially to enhance the imaging resolution of the CO2-plume, the time-lapse 3D seismic data have now been inverted for seismic impedances with different methods, which is the focus of this presentation. One difficulty

  8. 3D Finite Difference Modelling of Basaltic Region

    NASA Astrophysics Data System (ADS)

    Engell-Sørensen, L.

    2003-04-01

    The main purpose of the work was to generate realistic data to be applied for testing of processing and migration tools for basaltic regions. The project is based on the three - dimensional finite difference code (FD), TIGER, made by Sintef. The FD code was optimized (parallelized) by the author, to run on parallel computers. The parallel code enables us to model large-scale realistic geological models and to apply traditional seismic and micro seismic sources. The parallel code uses multiple processors in order to manipulate subsets of large amounts of data simultaneously. The general anisotropic code uses 21 elastic coefficients. Eight independent coefficients are needed as input parameters for the general TI medium. In the FD code, the elastic wave field computation is implemented by a higher order FD solution to the elastic wave equation and the wave fields are computed on a staggered grid, shifted half a node in one or two directions. The geological model is a gridded basalt model, which covers from 24 km to 37 km of a real shot line in horizontal direction and from the water surface to the depth of 3.5 km. The 2frac {1}{2}D model has been constructed using the compound modeling software from Norsk Hydro. The vertical parameter distribution is obtained from observations in two wells. At The depth of between 1100 m to 1500 m, a basalt horizon covers the whole sub surface layers. We have shown that it is possible to simulate a line survey in realistic (3D) geological models in reasonable time by using high performance computers. The author would like to thank Norsk Hydro, Statoil, GEUS, and SINTEF for very helpful discussions and Parallab for being helpful with the new IBM, p690 Regatta system.

  9. 3D Modeling Techniques for Print and Digital Media

    NASA Astrophysics Data System (ADS)

    Stephens, Megan Ashley

    In developing my thesis, I looked to gain skills using ZBrush to create 3D models, 3D scanning, and 3D printing. The models created compared the hearts of several vertebrates and were intended for students attending Comparative Vertebrate Anatomy. I used several resources to create a model of the human heart and was able to work from life while creating heart models from other vertebrates. I successfully learned ZBrush and 3D scanning, and successfully printed 3D heart models. ZBrush allowed me to create several intricate models for use in both animation and print media. The 3D scanning technique did not fit my needs for the project, but may be of use for later projects. I was able to 3D print using two different techniques as well.

  10. Joint earthquake source inversions using seismo-geodesy and 3-D earth models

    NASA Astrophysics Data System (ADS)

    Weston, J.; Ferreira, A. M. G.; Funning, G. J.

    2014-08-01

    A joint earthquake source inversion technique is presented that uses InSAR and long-period teleseismic data, and, for the first time, takes 3-D Earth structure into account when modelling seismic surface and body waves. Ten average source parameters (Moment, latitude, longitude, depth, strike, dip, rake, length, width and slip) are estimated; hence, the technique is potentially useful for rapid source inversions of moderate magnitude earthquakes using multiple data sets. Unwrapped interferograms and long-period seismic data are jointly inverted for the location, fault geometry and seismic moment, using a hybrid downhill Powell-Monte Carlo algorithm. While the InSAR data are modelled assuming a rectangular dislocation in a homogeneous half-space, seismic data are modelled using the spectral element method for a 3-D earth model. The effect of noise and lateral heterogeneity on the inversions is investigated by carrying out realistic synthetic tests for various earthquakes with different faulting mechanisms and magnitude (Mw 6.0-6.6). Synthetic tests highlight the improvement in the constraint of fault geometry (strike, dip and rake) and moment when InSAR and seismic data are combined. Tests comparing the effect of using a 1-D or 3-D earth model show that long-period surface waves are more sensitive than long-period body waves to the change in earth model. Incorrect source parameters, particularly incorrect fault dip angles, can compensate for systematic errors in the assumed Earth structure, leading to an acceptable data fit despite large discrepancies in source parameters. Three real earthquakes are also investigated: Eureka Valley, California (1993 May 17, Mw 6.0), Aiquile, Bolivia (1998 February 22, Mw 6.6) and Zarand, Iran (2005 May 22, Mw 6.5). These events are located in different tectonic environments and show large discrepancies between InSAR and seismically determined source models. Despite the 40-50 km discrepancies in location between previous geodetic and

  11. Converted-Wave Processing of a 3D-3C Refection Seismic Survey of Soda Lake Geothermal Field

    NASA Astrophysics Data System (ADS)

    Louie, J. N.; Kent, T.; Echols, J.

    2012-12-01

    This 3D-3C seismic survey greatly improves the structural model of the Soda Lake, Nevada geothermal system. The picked top of a mudstone interval above reservoir levels reveals a detailed fault map. The geothermal reservoir is within a complex of nested grabens. Determining a "geothermal indicator" for the deeper reservoir in the seismic signal, and processing of the 3D converted-wave data, have been unsuccessful to date. Due to a high near-surface Vp/Vs ratio the shear-wave energy is under-sampled with 220 ft receiver spacing and 550 ft (168 m) line spacing. The 2D converted-wave data that we can image shows encouraging similarity to the deep structural features in the P-wave sections, but have little resolution of shallow structures. Higher-density receivers and a better shallow shear-wave model are needed in conjunction with this deep reflection study to effectively image the 3D converted waves.

  12. Detection of ancient morphology and potential hydrocarbon traps using 3-D seismic data and attribute analysis

    SciTech Connect

    Heggland, R.

    1995-12-31

    This paper presents the use of seismic attributes on 3D data to reveal Tertiary and Cretaceous geological features in Norwegian block 9/2. Some of the features would hardly be possible to map using only 2D seismic data. The method which involves a precise interpretation of horizons, attribute analysis and manipulation of colour displays, may be useful when studying morphology, faults and hydrocarbon traps. The interval of interest in this study was from 0 to 1.5 s TWT. Horizontal displays (timeslices and attribute maps), seemed to highlight very nicely geological features such as shallow channels, fractures, karst topography and faults. The attributes used for mapping these features were amplitude, total reflection energy (a volume or time interval attribute), dip and azimuth. The choice of colour scale and manipulation of colour displays were also critical for the results. The data examples clearly demonstrate how it is possible to achieve a very detailed mapping of geological features using 3D seismic data and attribute analysis. The results of this study were useful for the understanding of hydrocarbon migration paths and hydrocarbon traps.

  13. 3D Geological Model of Nihe ore deposit Constrained by Gravity and Magnetic Modeling

    NASA Astrophysics Data System (ADS)

    Qi, Guang; Yan, Jiayong; Lv, Qingtan; Zhao, Jinhua

    2016-04-01

    We present a case study on using integrated geologic model in mineral exploration at depth. Nihe ore deposit in Anhui Province, is deep hidden ore deposit which was discovered in recent years, this finding is the major driving force of deep mineral exploration work in Luzong. Building 3D elaborate geological model has the important significance for prospecting to deep or surround in this area, and can help us better understand the metallogenic law and ore-controlling regularity. A 3D geological model, extending a depth from +200m to -1500m in Nihe ore deposit, has been compiled from surface geological map, cross-section, borehole logs and amounts of geological inference. And then the 3D geological models have been given physical property parameter for calculating the potential field. Modelling the potential response is proposed as means of evaluating the viability of the 3D geological models, and the evidence of making small changes to the uncertain parts of the original 3D geological models. It is expected that the final models not only reproduce supplied prior geological knowledge, but also explain the observed geophysical data. The workflow used to develop the 3D geologic model in this study includes the three major steps, as follows: (1) Determine the basic information of Model: Defining the 3D limits of the model area, the basic geological and structural unit, and the tectonic contact relations and the sedimentary sequences between these units. (2) 3D model construction: Firstly, a series of 2D geological cross sections over the model area are built by using all kinds of prior information, including surface geology, borehole data, seismic sections, and local geologists' knowledge and intuition. Lastly, we put these sections into a 3D environment according to their profile locations to build a 3D model by using geostatistics method. (3) 3D gravity and magnetic modeling: we calculate the potential field responses of the 3D model, and compare the predicted and

  14. Midget Seismic in Sandbox Models

    NASA Astrophysics Data System (ADS)

    Krawczyk, C. M.; Buddensiek, M. L.; Philipp, J.; Kukowski, N.; Oncken, O.

    2008-12-01

    Analog sandbox simulation has been applied to study geological processes to provide qualitative and quantitative insights into specific geological problems. In nature, the structures, which are simulated in those sandbox models, are often inferred from seismic data. With the study introduced here, we want to combine the analog sandbox simulation techniques with seismic physical modeling of those sandbox models. The long-term objectives of this approach are (1) imaging of seismic and seismological events of actively deforming and static 3D analogue models, and (2) assessment of the transferability of the model data to field data in order to improve field data acquisition and interpretation according to the addressed geological problem. To achieve this objective, a new midget-seismic facility for laboratory use was designed and developed, comprising a seismic tank, a PC control unit including piezo-electric transducers, and a positioning system. The first experiments are aimed at studying the wave field properties of the piezo- transducers in order to investigate their feasibility for seismic profiling. The properties investigated are their directionality and the change of waveform due to their size (5-12 mm) compared to the wavelengths (< 1.5 mm). The best quality signals and least directionality and waveform change are achieved when the center source frequency is between 350-500 kHz, and the offset is less than 8 cm for a reflector depth of 10 cm. With respect to the technical hardware reflection processing on such a small scale is feasible as long as the offset does not exceed a certain value, which is dependent on the reflector depth and frequency. The next steps will include a study of material properties and the effects of wave propagation in an-/isotropic media by physical studies, before we finally start using different seismic imaging and processing techniques on static and actively deforming 3D analog models.

  15. Time-lapse analysis of sparse 3D seismic data from the CO2 storage pilot site at Ketzin, Germany

    NASA Astrophysics Data System (ADS)

    Ivandic, M.; Yang, C.; Lüth, S.; Cosma, C.; Juhlin, C.

    2012-04-01

    Capture and geological storage of CO2 is considered to be a feasible method for reducing carbon emissions. In April 2004, a research pilot project in the German town of Ketzin started as the first onshore CO2 storage project in Europe. Injection started in June 2008 and until the latest repeat survey in February 2011 around 45 kilotons of CO2 had been injected into a saline aquifer at approximately 630-650 m depth. Different seismic methods, such as time-lapse Vertical Seismic Profiling (VSP), Crosswell, Moving Source Profiling (MSP) and surface seismics have been employed to detect and monitor changes in the reservoir. We present here time-lapse results from sparse 3D seismic surveying with a "star" geometry, i.e. with a radial distribution of acquisition profiles directed towards the approximate location of the injection well, which were acquired to link downhole surveys with full 3D surface seismic surveys. The main objectives of the sparse 3D surveys were (1) to identify changes in the seismic response related to the injection of CO2 between the repeat surveys and baseline survey and (2) to compare these results with those from the repeat 3D seismic survey. The results are consistent with the 3D seismic time-lapse studies over the injection site and show that the sparse 3D geometry can be used to qualitatively map the migration of the CO2 plume within the saline reservoir, as well as potential migration out of the reservoir rock at a significantly lower effort than the full 3D surveying. The latest repeat survey indicates preferential migration of the CO2 to the west. Both sparse 3D repeat surveys show that the CO2 is being confined within the aquifer, implying that there is no leakage into the caprock at the time of the repeat surveys. The same observation was obtained from the 3D dataset.

  16. Reducing Disk Storage of Full-3D Seismic Waveform Tomography (F3DT) Through Lossy Online Compression

    SciTech Connect

    Lindstrom, Peter; Chen, Po; Lee, En-Jui

    2016-05-05

    Full-3D seismic waveform tomography (F3DT) is the latest seismic tomography technique that can assimilate broadband, multi-component seismic waveform observations into high-resolution 3D subsurface seismic structure models. The main drawback in the current F3DT implementation, in particular the scattering-integral implementation (F3DT-SI), is the high disk storage cost and the associated I/O overhead of archiving the 4D space-time wavefields of the receiver- or source-side strain tensors. The strain tensor fields are needed for computing the data sensitivity kernels, which are used for constructing the Jacobian matrix in the Gauss-Newton optimization algorithm. In this study, we have successfully integrated a lossy compression algorithm into our F3DT SI workflow to significantly reduce the disk space for storing the strain tensor fields. The compressor supports a user-specified tolerance for bounding the error, and can be integrated into our finite-difference wave-propagation simulation code used for computing the strain fields. The decompressor can be integrated into the kernel calculation code that reads the strain fields from the disk and compute the data sensitivity kernels. During the wave-propagation simulations, we compress the strain fields before writing them to the disk. To compute the data sensitivity kernels, we read the compressed strain fields from the disk and decompress them before using them in kernel calculations. Experiments using a realistic dataset in our California statewide F3DT project have shown that we can reduce the strain-field disk storage by at least an order of magnitude with acceptable loss, and also improve the overall I/O performance of the entire F3DT-SI workflow significantly. The integration of the lossy online compressor may potentially open up the possibilities of the wide adoption of F3DT-SI in routine seismic tomography practices in the near future.

  17. Application of Cutting-Edge 3D Seismic Attribute Technology to the Assessment of Geological Reservoirs for CO2 Sequestration

    SciTech Connect

    Christopher Liner; Jianjun Zeng; Po Geng Heather King Jintan Li; Jennifer Califf; John Seales

    2010-03-31

    The goals of this project were to develop innovative 3D seismic attribute technologies and workflows to assess the structural integrity and heterogeneity of subsurface reservoirs with potential for CO{sub 2} sequestration. Our specific objectives were to apply advanced seismic attributes to aide in quantifying reservoir properies and lateral continuity of CO{sub 2} sequestration targets. Our study area is the Dickman field in Ness County, Kansas, a type locality for the geology that will be encountered for CO{sub 2} sequestration projects from northern Oklahoma across the U.S. midcontent to Indiana and beyond. Since its discovery in 1962, the Dickman Field has produced about 1.7 million barrels of oil from porous Mississippian carbonates with a small structural closure at about 4400 ft drilling depth. Project data includes 3.3 square miles of 3D seismic data, 142 wells, with log, some core, and oil/water production data available. Only two wells penetrate the deep saline aquifer. Geological and seismic data were integrated to create a geological property model and a flow simulation grid. We systematically tested over a dozen seismic attributes, finding that curvature, SPICE, and ANT were particularly useful for mapping discontinuities in the data that likely indicated fracture trends. Our simulation results in the deep saline aquifer indicate two effective ways of reducing free CO{sub 2}: (a) injecting CO{sub 2} with brine water, and (b) horizontal well injection. A tuned combination of these methods can reduce the amount of free CO{sub 2} in the aquifer from over 50% to less than 10%.

  18. Reducing disk storage of full-3D seismic waveform tomography (F3DT) through lossy online compression

    NASA Astrophysics Data System (ADS)

    Lindstrom, Peter; Chen, Po; Lee, En-Jui

    2016-08-01

    Full-3D seismic waveform tomography (F3DT) is the latest seismic tomography technique that can assimilate broadband, multi-component seismic waveform observations into high-resolution 3D subsurface seismic structure models. The main drawback in the current F3DT implementation, in particular the scattering-integral implementation (F3DT-SI), is the high disk storage cost and the associated I/O overhead of archiving the 4D space-time wavefields of the receiver- or source-side strain tensors. The strain tensor fields are needed for computing the data sensitivity kernels, which are used for constructing the Jacobian matrix in the Gauss-Newton optimization algorithm. In this study, we have successfully integrated a lossy compression algorithm into our F3DT-SI workflow to significantly reduce the disk space for storing the strain tensor fields. The compressor supports a user-specified tolerance for bounding the error, and can be integrated into our finite-difference wave-propagation simulation code used for computing the strain fields. The decompressor can be integrated into the kernel calculation code that reads the strain fields from the disk and compute the data sensitivity kernels. During the wave-propagation simulations, we compress the strain fields before writing them to the disk. To compute the data sensitivity kernels, we read the compressed strain fields from the disk and decompress them before using them in kernel calculations. Experiments using a realistic dataset in our California statewide F3DT project have shown that we can reduce the strain-field disk storage by at least an order of magnitude with acceptable loss, and also improve the overall I/O performance of the entire F3DT-SI workflow significantly. The integration of the lossy online compressor may potentially open up the possibilities of the wide adoption of F3DT-SI in routine seismic tomography practices in the near future.

  19. Elastic wave modelling in 3D heterogeneous media: 3D grid method

    NASA Astrophysics Data System (ADS)

    Jianfeng, Zhang; Tielin, Liu

    2002-09-01

    We present a new numerical technique for elastic wave modelling in 3D heterogeneous media with surface topography, which is called the 3D grid method in this paper. This work is an extension of the 2D grid method that models P-SV wave propagation in 2D heterogeneous media. Similar to the finite-element method in the discretization of a numerical mesh, the proposed scheme is flexible in incorporating surface topography and curved interfaces; moreover it satisfies the free-surface boundary conditions of 3D topography naturally. The algorithm, developed from a parsimonious staggered-grid scheme, solves the problem using integral equilibrium around each node, instead of satisfying elastodynamic differential equations at each node as in the conventional finite-difference method. The computational cost and memory requirements for the proposed scheme are approximately the same as those used by the same order finite-difference method. In this paper, a mixed tetrahedral and parallelepiped grid method is presented; and the numerical dispersion and stability criteria on the tetrahedral grid method and parallelepiped grid method are discussed in detail. The proposed scheme is successfully tested against an analytical solution for the 3D Lamb problem and a solution of the boundary method for the diffraction of a hemispherical crater. Moreover, examples of surface-wave propagation in an elastic half-space with a semi-cylindrical trench on the surface and 3D plane-layered model are presented.

  20. The 3D rocket combustor acoustics model

    NASA Technical Reports Server (NTRS)

    Priem, Richard J.; Breisacher, Kevin J.

    1992-01-01

    The theory and procedures for determining the characteristics of pressure oscillations in rocket engines with prescribed burning rate oscillations are presented. Analyses including radial and hub baffles and absorbers can be performed in one, two, and three dimensions. Pressure and velocity oscillations calculated using this procedure are presented for the SSME to show the influence of baffles and absorbers on the burning rate oscillations required to achieve neutral stability. Comparisons are made between the results obtained utilizing 1-D, 2-D, and 3-D assumptions with regards to capturing the physical phenomena of interest and computational requirements.

  1. 3D modeling based on CityEngine

    NASA Astrophysics Data System (ADS)

    Jia, Guangyin; Liao, Kaiju

    2017-03-01

    Currently, there are many 3D modeling softwares, like 3DMAX, AUTOCAD, and more populous BIM softwares represented by REVIT. CityEngine modeling software introduced in this paper can fully utilize the existing GIS data and combine other built models to make 3D modeling on internal and external part of buildings in a rapid and batch manner, so as to improve the 3D modeling efficiency.

  2. Joint Stochastic Inversion of Pre-Stack 3D Seismic Data and Well Logs for High Resolution Hydrocarbon Reservoir Characterization

    NASA Astrophysics Data System (ADS)

    Torres-Verdin, C.

    2007-05-01

    This paper describes the successful implementation of a new 3D AVA stochastic inversion algorithm to quantitatively integrate pre-stack seismic amplitude data and well logs. The stochastic inversion algorithm is used to characterize flow units of a deepwater reservoir located in the central Gulf of Mexico. Conventional fluid/lithology sensitivity analysis indicates that the shale/sand interface represented by the top of the hydrocarbon-bearing turbidite deposits generates typical Class III AVA responses. On the other hand, layer- dependent Biot-Gassmann analysis shows significant sensitivity of the P-wave velocity and density to fluid substitution. Accordingly, AVA stochastic inversion, which combines the advantages of AVA analysis with those of geostatistical inversion, provided quantitative information about the lateral continuity of the turbidite reservoirs based on the interpretation of inverted acoustic properties (P-velocity, S-velocity, density), and lithotype (sand- shale) distributions. The quantitative use of rock/fluid information through AVA seismic amplitude data, coupled with the implementation of co-simulation via lithotype-dependent multidimensional joint probability distributions of acoustic/petrophysical properties, yields accurate 3D models of petrophysical properties such as porosity and permeability. Finally, by fully integrating pre-stack seismic amplitude data and well logs, the vertical resolution of inverted products is higher than that of deterministic inversions methods.

  3. Single-Tooth Modeling for 3D Dental Model

    PubMed Central

    Yuan, Tianran; Liao, Wenhe; Dai, Ning; Cheng, Xiaosheng; Yu, Qing

    2010-01-01

    An integrated single-tooth modeling scheme is proposed for the 3D dental model acquired by optical digitizers. The cores of the modeling scheme are fusion regions extraction, single tooth shape restoration, and single tooth separation. According to the “valley” shape-like characters of the fusion regions between two adjoining teeth, the regions of the 3D dental model are analyzed and classified based on the minimum curvatures of the surface. The single tooth shape is restored according to the bioinformation along the hole boundary, which is generated after the fusion region being removed. By using the extracted boundary from the blending regions between the teeth and soft tissues as reference, the teeth can be separated from the 3D dental model one by one correctly. Experimental results show that the proposed method can achieve satisfying modeling results with high-degree approximation of the real tooth and meet the requirements of clinical oral medicine. PMID:20689718

  4. Brandenburg 3D - a comprehensive 3D Subsurface Model, Conception of an Infrastructure Node and a Web Application

    NASA Astrophysics Data System (ADS)

    Kerschke, Dorit; Schilling, Maik; Simon, Andreas; Wächter, Joachim

    2014-05-01

    application enables an intuitive navigation through all available information and allows the visualization of geological maps (2D), seismic transects (2D/3D), wells (2D/3D), and the 3D-model. These achievements will alleviate spatial and geological data management within the German State Geological Offices and foster the interoperability of heterogeneous systems. It will provide guidance to a systematic subsurface management across system, domain and administrative boundaries on the basis of a federated spatial data infrastructure, and include the public in the decision processes (e-Governance). Yet, the interoperability of the systems has to be strongly propelled forward through agreements on standards that need to be decided upon in responsible committees. The project B3D is funded with resources from the European Fund for Regional Development (EFRE).

  5. 3D tumor models: history, advances and future perspectives.

    PubMed

    Benien, Parul; Swami, Archana

    2014-05-01

    Evaluation of cancer therapeutics by utilizing 3D tumor models, before clinical studies, could be more advantageous than conventional 2D tumor models (monolayer cultures). The 3D systems mimic the tumor microenvironment more closely than 2D systems. The following review discusses the various 3D tumor models present today with the advantages and limitations of each. 3D tumor models replicate the elements of a tumor microenvironment such as hypoxia, necrosis, angiogenesis and cell adhesion. The review introduces application of techniques such as microfluidics, imaging and tissue engineering to improve the 3D tumor models. Despite their tremendous potential to better screen chemotherapeutics, 3D tumor models still have a long way to go before they are used commonly as in vitro tumor models in pharmaceutical industrial research.

  6. 3-D Seismic Exploration Project, Ute Indian Tribe, Uintah and Ouray Reservation, Uintah County, Utah

    SciTech Connect

    Eckels, Marc T.

    2002-09-09

    The objectives of this North Hill Creek 3-D seismic survey were to: (1) cover as large an area as possible with available budget; (2) obtain high quality data throughout the depth range of the prospective geologic formations of 2,000' to 12,000' to image both gross structures and more subtle structural and stratigraphic elements; (3) overcome the challenges posed by a hard, reflective sandstone that cropped out or was buried just a few feet below the surface under most of the survey area; and (4) run a safe survey.

  7. 3D seismic attribute-assisted analysis of microseismic events in the Marcellus Shale

    NASA Astrophysics Data System (ADS)

    Hart, Ariel Kelton

    Microseismic monitoring is often used during the process of oil and gas exploitation to monitor seismicity that may be triggered by hydraulic fracturing, a common practice in the Appalachian Basin. Anthropogenically-induced minor upward fracture growth is not uncommon in the Marcellus shale; however, in the area of study, significant microseismic activity was registered above the target zone. In order to ascertain whether out-of-zone growth might have been predictable and identify which areas are more likely to experience brittle failure first, 3D seismic and microseismic data were analyzed with a focus on better understanding variations in the acoustic properties associated with unconventional naturally fractured reservoirs. Ant Tracking was used to identify areas of increased local seismic discontinuity, as these areas are generally more intensely deformed and may represent zones of increased fracture intensity. Ant Tracking results reveal discontinuities in the Marcellus are oriented approximately at N52E and N41W; discontinuities do not coincide with N25E trending folds apparent in the 3D seismic, but tend to follow deeper structural trends instead. These discontinuity orientations are interpreted to be a result of continued movement on deeper faults throughout the Paleozoic; these faults possibly acted as seed points for fractures further upsection and potentially led to the precipitation of the large N25E trending imbricate backthrusts seen in the 3D seismic. The reservoir's response to hydraulic fracturing also provided insights into local stress anisotropy and into optimal well and stage spacing needed to maximize drainage area and locate additional wells during the field development phase. Microseismic, well, and pump data used to gauge the reservoir's response to a hydraulic fracture treatment indicated that the number of stages, lateral length, total proppant volume, and fracture energy heavily influence how a well produces. SHmax in the area is oriented

  8. 3D insight into fault geometries, deformation, and fluid-migration within the Hosgri Fault Zone offshore central California: Results from high-resolution 3D seismic data

    NASA Astrophysics Data System (ADS)

    Kluesner, J.; Brothers, D. S.; Johnson, S. Y.; Watt, J. T.

    2015-12-01

    High-resolution 3D seismic P-Cable data and advanced seismic attribute analyses were used to detect and interpret complex strike-slip fault geometries, deformation patterns, and fluid-pathways across a portion of the Hosgri Fault Zone (HFZ) offshore central California. Combination of the fault attribute results with structural analysis provides 3D insight into the geometry and internal structure of restraining and releasing bends, step-over zones, fault convergence zones, and apparent paired fault bends. The 3D seismic volume covers a 13.7 km2 region along the HFZ offshore of Point Sal and was collected in 2012 as part of the PG&E Central California Seismic Imaging Project (PG&E, 2014). Application of the fault attribute workflow isolated and delineated fault strands within the 3D volume. These results revealed that the northern and southern edges of the survey region are characterized by single fault strands that exhibit an approximate 6° change in strike across the 3D volume. Between these single faults strands is a complex network of fault splays, bends, stepovers, and convergence zones. Structural analysis reveals that the southern portion of the HFZ in the region is characterized by transtensional deformation, whereas transpressional-related folding dominates the central and northern portions of the HFZ. In the central region, convergence of the Lions Head Fault from the southeast results in an apparent impinging block, leading to development of a "paired fault bend" to the west. Combination of the fault and "chimney" attribute results indicates a strong connection between faults and fluid-migration pathways. Fluid-pathways are concentrated along discrete faults in the transtensional zones, but appear to be more broadly distributed amongst fault bounded anticlines and structurally controlled traps in the transpressional zones.

  9. 3D Face modeling using the multi-deformable method.

    PubMed

    Hwang, Jinkyu; Yu, Sunjin; Kim, Joongrock; Lee, Sangyoun

    2012-09-25

    In this paper, we focus on the problem of the accuracy performance of 3D face modeling techniques using corresponding features in multiple views, which is quite sensitive to feature extraction errors. To solve the problem, we adopt a statistical model-based 3D face modeling approach in a mirror system consisting of two mirrors and a camera. The overall procedure of our 3D facial modeling method has two primary steps: 3D facial shape estimation using a multiple 3D face deformable model and texture mapping using seamless cloning that is a type of gradient-domain blending. To evaluate our method's performance, we generate 3D faces of 30 individuals and then carry out two tests: accuracy test and robustness test. Our method shows not only highly accurate 3D face shape results when compared with the ground truth, but also robustness to feature extraction errors. Moreover, 3D face rendering results intuitively show that our method is more robust to feature extraction errors than other 3D face modeling methods. An additional contribution of our method is that a wide range of face textures can be acquired by the mirror system. By using this texture map, we generate realistic 3D face for individuals at the end of the paper.

  10. Investigation into 3D earth structure and sources using full seismic waveforms

    NASA Astrophysics Data System (ADS)

    Covellone, Brian M.

    Seismograms are the result of the complex interactions between a seismic source, a propagation medium and the seismograph's response. Through the use of 3-dimensional modeling and full seismic waveform data, we quantify and minimize errors associated with the source and propagation medium within our data sets. We compile a new and unique earthquake catalog for the Middle East that is openly available to the public. We quantify the benefits of using a 3-dimensional model relative to a 1-dimensional model to minimizing error in earthquake moment tensors and identify where in the waveform 3-dimensional models outperform 1-dimensional models. Two new and unique 3-dimensional seismic wave speed models are computed for the Ontong Java plateau and eastern North American margin.Both models are significant improvements to the resolution of wave speed structures in the crust and upper mantle and provide new information for the evaluation of tectonic features.

  11. 3D crustal velocity structure beneath the broadband seismic array in the Gyeongju area of Korea by receiver function analyses

    NASA Astrophysics Data System (ADS)

    Lee, Dong Hun; Lee, Jung Mo; Cho, Hyun-Moo; Kang, Tae-Seob

    2016-10-01

    A temporary seismic array was in operation between October 2010 and March 2013 in the Gyeongju area of Korea. Teleseismic records of the seismic array appropriate for receiver function analysis were collected, and selected seismograms were split into five groups based on epicenters-the Banda-Molucca, Sumatra, Iran, Aleutian, and Vanuatu groups. 1D velocity structures beneath each seismic station were estimated by inverting the stacked receiver functions for possible groups. The inversion was done by applying a genetic algorithm, whereas surface wave dispersion data were used as constraints to avoid non-uniqueness in the inversion. The composite velocity structure was constructed by averaging the velocity structures weighted by the number of receiver functions used in stacking. The uncertainty analysis for the velocity structures showed that the average of 95% confidence intervals was ± 0.1 km/s. The 3D velocity structure was modeled through interpolation of 1D composite velocity structures. Moho depths were determined in each composite velocity structure based on the AK135-F S-wave velocity model, and the depths were similar to the H-κ analysis results. The deepest Moho depth in the study area was found to be 31.9 km, and the shallowest, was 25.9 km. The Moho discontinuity dips in a southwestward direction beneath the area. A low velocity layer was also detected between 4 and 14 km depth. Adakitic intrusions and/or a high geothermal gradient appear to be the causes of this low velocity layer. The 3D velocity structure can be used to reliably assess seismic hazards in this area.

  12. 3D interpretation of SHARAD radargram data using seismic processing routines

    NASA Astrophysics Data System (ADS)

    Kleuskens, M. H. P.; Oosthoek, J. H. P.

    2009-04-01

    Ground penetrating radar on board a satellite has entered the field of planetary geology. Two radars enable subsurface observations of Mars. In 2003, ESA launched the Mars Express equipped with MARSIS, a low frequency radar which was able to detect only the base of the ice caps. Since December 2006, the Shallow Radar (SHARAD) of Agenzia Spaziale Italiana (ASI) on board the NASA Mars Reconnaissance Orbiter (MRO) is active in orbit around Mars. The SHARAD radar covers the frequency band between 15 and 25 MHz. The vertical resolution is about 15 m in free space. The horizontal resolution is 300-1000 m along track and 1500-8000 m across track. The radar penetrates the subsurface of Mars up to 2 km deep, and is capable of detecting multiple reflections in the ice caps of Mars. Considering the scarcity of planetary data relative to terrestrial data, it is essential to combine all available types of data of an area of interest. Up to now SHARAD data has only been interpreted separately as 2D radargrams. The Geological Survey of the Netherlands has decades of experience in interpreting 2D and 3D seismic data of the Dutch subsurface, especially for the 3D interpretation of reservoir characteristics of the deeper subsurface. In this abstract we present a methodology which can be used for 3D interpretation of SHARAD data combined with surface data using state-of-the art seismic software applied in the oil and gas industry. We selected a region that would be most suitable to demonstrate 3D interpretation. The Titania Lobe of the North Polar ice cap was selected based on the abundancy of radar data and the complexity of the ice lobe. SHARAD data is released to the scientific community via the Planetary Data System. It includes ‘Reduced Data Records' (RDR) data, a binary format which contains the radargram. First the binary radargram data and corresponding coordinates were combined and converted to the commonly used seismic seg-y format. Second, we used the reservoir

  13. New results from a 3D seismic academic dataset across the west Galicia margin

    NASA Astrophysics Data System (ADS)

    Lymer, Gaël; Cresswell, Derren; Reston, Tim; Stevenson, Carl; Sawyer, Dale

    2016-04-01

    The west Galicia margin (western Spain) is a magma-poor margin and has limited sedimentary cover, providing ideal conditions to study the processes of continental extension and break-up through seismic imaging. The margin is characterised by hyper-extended continental crust, well defined rotated faults blocks with associated syn-kinematic sedimentary wedges, and exhumed serpentinized continental mantle. Faulted blocks overlie a bright reflection, the S reflector, generally interpreted as both a detachment and the crust-mantle boundary. But open questions remain concerning the role of the S detachment in extension leading to breakup. To study further the S reflection and its role in continental breakup, a new 3D high-resolution multi-channel seismic dataset has been acquired over the Galicia margin during summer 2013. It consists in 800 inlines and 5000 crosslines distributed on a ~680 km2 areal. This 3D dataset is thus the largest academic one of its kind. It extends across the edge of the continental crust and captures the 3D nature of extension and break-up of the northern Atlantic continental margins. Here we present some results from our interpretations of the 3D volume, which allow various horizons, including the base of the post-rift sedimentary cover, the top basement and the S reflector, to be mapped out in 3D. These maps provide 3D views of the margin structure and also reveal the texture of each horizon. We also focus on the internal structure of some of the faulted blocks through interpretation of the crustal normal faults. The main normal faults are generally connected downward on the S reflector, revealing strong interactions between crustal thinning and the S. The half-grabens and the fault blocks are dominantly N-S oriented, but the crustal structures vary both along strike and cross strike. We particularly observe an intriguingly NW-SE trend, highlighted by a pronounced low within the crest of the fault blocks. We also observe this trend from

  14. SEISVIZ3D: Stereoscopic system for the representation of seismic data - Interpretation and Immersion

    NASA Astrophysics Data System (ADS)

    von Hartmann, Hartwig; Rilling, Stefan; Bogen, Manfred; Thomas, Rüdiger

    2015-04-01

    The seismic method is a valuable tool for getting 3D-images from the subsurface. Seismic data acquisition today is not only a topic for oil and gas exploration but is used also for geothermal exploration, inspections of nuclear waste sites and for scientific investigations. The system presented in this contribution may also have an impact on the visualization of 3D-data of other geophysical methods. 3D-seismic data can be displayed in different ways to give a spatial impression of the subsurface.They are a combination of individual vertical cuts, possibly linked to a cubical portion of the data volume, and the stereoscopic view of the seismic data. By these methods, the spatial perception for the structures and thus of the processes in the subsurface should be increased. Stereoscopic techniques are e. g. implemented in the CAVE and the WALL, both of which require a lot of space and high technical effort. The aim of the interpretation system shown here is stereoscopic visualization of seismic data at the workplace, i.e. at the personal workstation and monitor. The system was developed with following criteria in mind: • Fast rendering of large amounts of data so that a continuous view of the data when changing the viewing angle and the data section is possible, • defining areas in stereoscopic view to translate the spatial impression directly into an interpretation, • the development of an appropriate user interface, including head-tracking, for handling the increased degrees of freedom, • the possibility of collaboration, i.e. teamwork and idea exchange with the simultaneous viewing of a scene at remote locations. The possibilities offered by the use of a stereoscopic system do not replace a conventional interpretation workflow. Rather they have to be implemented into it as an additional step. The amplitude distribution of the seismic data is a challenge for the stereoscopic display because the opacity level and the scaling and selection of the data have to

  15. 3D Modelling of X-pinches.

    NASA Astrophysics Data System (ADS)

    Ciardi, A.; Chittenden, J. P.; Lebedev, S. V.; Bland, S. N.; Jennings, C. A.

    2003-10-01

    X-pinch produced plasmas are an intense source of soft x-rays generated by passing a large, fast rising current through two or more thin metallic wires crossed in the shape of <93>an "X". During the current pulse, the plasma is pinched at the crossing point where a dense Z-pinch plasma column develops. Further compression produces micron sized x-ray hot spots with energy densities in excess of ˜10^24 eV cm-3. We present 3D resistive magnetohydrodynamic simulations of two- and four-wire X-pinches for a variety of wire materials. The simulations naturally follow the evolution of the X-pinch: jet-like structures on axis, formation of a Z-pinch and its subsequent rapid evolution and production of x-ray hot spots. The effects of wire material and wire number are studied with particular consideration to the relationship between the magnetic confinement and radiative cooling mechanisms, which ultimately determine the complex behaviour of the X-pinch.

  16. Comparing a quasi-3D to a full 3D nearshore circulation model: SHORECIRC and ROMS

    USGS Publications Warehouse

    Haas, K.A.; Warner, J.C.

    2009-01-01

    Predictions of nearshore and surf zone processes are important for determining coastal circulation, impacts of storms, navigation, and recreational safety. Numerical modeling of these systems facilitates advancements in our understanding of coastal changes and can provide predictive capabilities for resource managers. There exists many nearshore coastal circulation models, however they are mostly limited or typically only applied as depth integrated models. SHORECIRC is an established surf zone circulation model that is quasi-3D to allow the effect of the variability in the vertical structure of the currents while maintaining the computational advantage of a 2DH model. Here we compare SHORECIRC to ROMS, a fully 3D ocean circulation model which now includes a three dimensional formulation for the wave-driven flows. We compare the models with three different test applications for: (i) spectral waves approaching a plane beach with an oblique angle of incidence; (ii) monochromatic waves driving longshore currents in a laboratory basin; and (iii) monochromatic waves on a barred beach with rip channels in a laboratory basin. Results identify that the models are very similar for the depth integrated flows and qualitatively consistent for the vertically varying components. The differences are primarily the result of the vertically varying radiation stress utilized by ROMS and the utilization of long wave theory for the radiation stress formulation in vertical varying momentum balance by SHORECIRC. The quasi-3D model is faster, however the applicability of the fully 3D model allows it to extend over a broader range of processes, temporal, and spatial scales. ?? 2008 Elsevier Ltd.

  17. a Fast Method for Measuring the Similarity Between 3d Model and 3d Point Cloud

    NASA Astrophysics Data System (ADS)

    Zhang, Zongliang; Li, Jonathan; Li, Xin; Lin, Yangbin; Zhang, Shanxin; Wang, Cheng

    2016-06-01

    This paper proposes a fast method for measuring the partial Similarity between 3D Model and 3D point Cloud (SimMC). It is crucial to measure SimMC for many point cloud-related applications such as 3D object retrieval and inverse procedural modelling. In our proposed method, the surface area of model and the Distance from Model to point Cloud (DistMC) are exploited as measurements to calculate SimMC. Here, DistMC is defined as the weighted distance of the distances between points sampled from model and point cloud. Similarly, Distance from point Cloud to Model (DistCM) is defined as the average distance of the distances between points in point cloud and model. In order to reduce huge computational burdens brought by calculation of DistCM in some traditional methods, we define SimMC as the ratio of weighted surface area of model to DistMC. Compared to those traditional SimMC measuring methods that are only able to measure global similarity, our method is capable of measuring partial similarity by employing distance-weighted strategy. Moreover, our method is able to be faster than other partial similarity assessment methods. We demonstrate the superiority of our method both on synthetic data and laser scanning data.

  18. Subsurface fault geometries in Southern California illuminated through Full-3D Seismic Waveform Tomography (F3DT)

    NASA Astrophysics Data System (ADS)

    Lee, En-Jui; Chen, Po

    2017-04-01

    More precise spatial descriptions of fault systems play an essential role in tectonic interpretations, deformation modeling, and seismic hazard assessments. The recent developed full-3D waveform tomography techniques provide high-resolution images and are able to image the material property differences across faults to assist the understanding of fault systems. In the updated seismic velocity model for Southern California, CVM-S4.26, many velocity gradients show consistency with surface geology and major faults defined in the Community Fault Model (CFM) (Plesch et al. 2007), which was constructed by using various geological and geophysical observations. In addition to faults in CFM, CVM-S4.26 reveals a velocity reversal mainly beneath the San Gabriel Mountain and Western Mojave Desert regions, which is correlated with the detachment structure that has also been found in other independent studies. The high-resolution tomographic images of CVM-S4.26 could assist the understanding of fault systems in Southern California and therefore benefit the development of fault models as well as other applications, such as seismic hazard analysis, tectonic reconstructions, and crustal deformation modeling.

  19. 3D Seismic Imaging of a Geological Storage of CO2 Site: Hontomín (Spain)

    NASA Astrophysics Data System (ADS)

    Alcalde, Juan; Martí, David; Juhlin, Christopher; Malehmir, Alireza; Sopher, Daniel; Marzán, Ignacio; Calahorrano, Alcinoe; Ayarza, Puy; Pérez-Estaún, Andrés; Carbonell, Ramon

    2013-04-01

    A 3D seismic reflection survey was acquired in the summer of 2010 over the Hontomín CO2 storage site (Spain), with the aim of imaging its internal structure and to provide a 3D seismic baseline model prior to CO2 injection. The 36 km2 survey utilised 25 m source and receiver point spacing and 5000 shotpoints recorded with mixed source (Vibroseis and explosives). The target reservoir is a saline aquifer located at approximately 1450 m, within Lower Jurassic carbonates (Lias). The main seal is formed by inter-layered marls and marly limestones of Early to Middle Jurassic age (Dogger and Lias). The relatively complex geology and the rough topography strongly influenced the selection of parameters for the data processing. Static corrections and post stack migration were shown to be the most important processes affecting the quality of the final image. The match between the differing source wavelets is also studied here. The resulting 3D image provides information of all the relevant geological features of the storage site, including position and shape of the main underground formations. The target structure is an asymmetric dome. The steepest flank of the structure was selected as the optimum location for CO2 injection, where the updip migration of the plume is anticipated. A major strike slip fault (the South fault), crossing the study area W-E, has been mapped through the whole seismic volume. The injection position and the expected migration plume are located to the north of this main fault and away from its influence.

  20. Visualization of 3D Geological Models on Google Earth

    NASA Astrophysics Data System (ADS)

    Choi, Y.; Um, J.; Park, M.

    2013-05-01

    Google Earth combines satellite imagery, aerial photography, thematic maps and various data sets to make a three-dimensional (3D) interactive image of the world. Currently, Google Earth is a popular visualization tool in a variety of fields and plays an increasingly important role not only for private users in daily life, but also for scientists, practitioners, policymakers and stakeholders in research and application. In this study, a method to visualize 3D geological models on Google Earth is presented. COLLAborative Design Activity (COLLADA, an open standard XML schema for establishing interactive 3D applications) was used to represent different 3D geological models such as borehole, fence section, surface-based 3D volume and 3D grid by triangle meshes (a set of triangles connected by their common edges or corners). In addition, we designed Keyhole Markup Language (KML, the XML-based scripting language of Google Earth) codes to import the COLLADA files into the 3D render window of Google Earth. The method was applied to the Grosmont formation in Alberta, Canada. The application showed that the combination of COLLADA and KML enables Google Earth to effectively visualize 3D geological structures and properties.; Visualization of the (a) boreholes, (b) fence sections, (c) 3D volume model and (d) 3D grid model of Grossmont formation on Google Earth

  1. A 3D Geometry Model Search Engine to Support Learning

    ERIC Educational Resources Information Center

    Tam, Gary K. L.; Lau, Rynson W. H.; Zhao, Jianmin

    2009-01-01

    Due to the popularity of 3D graphics in animation and games, usage of 3D geometry deformable models increases dramatically. Despite their growing importance, these models are difficult and time consuming to build. A distance learning system for the construction of these models could greatly facilitate students to learn and practice at different…

  2. [Potentials of 3D-modeling in reconstructive orbital surgery].

    PubMed

    Butsan, S B; Khokhlachev, S B; Ĭigitaliev, Sh N; Zaiakin, Ia A

    2012-01-01

    A technique of bone reconstructive surgery of orbitofrontonasomalar region using 3D-modeling based on multispiral computer tomography data is presented. The efficacy of intraoperative templates created using 3D-modeling was showed for harvesting and modeling of bone calvarial autografts. The steps of reconstructive procedure are explained in details for repair of medial and inferior orbital fractures.

  3. Hydrocarbon Seeps Formations: a Study Using 3-D Seismic Attributes in Combination with Satellite Data

    NASA Astrophysics Data System (ADS)

    Garcia-Pineda, O. G.; MacDonald, I. R.; Shedd, W.

    2011-12-01

    Analyzing the magnitude of oil discharges from natural hydrocarbon seeps is important in improving our understanding of carbon contribution as oil migrates from deeper sediments to the water column, and then eventually to the atmosphere. Liquid hydrocarbon seepage in the deep water of the Gulf of Mexico (GOM) is associated with deep cutting faults, associated with vertical salt movement, that provide conduits for the upward migration of oil and gas. Seeps transform surface geology and generate prominent geophysical targets that can be identified on 3-D seismic data as seafloor amplitude anomalies maps that correlate with the underlying deep fault systems. Using 3D seismic data, detailed mapping of the northern GOM has identified more than 21,000 geophysical anomalies across the basin. In addition to seismic data, Synthetic Aperture Radar (SAR) images have proven to be a reliable tool for localizing natural seepage of oil. We used a Texture Classifier Neural Network Algorithm (TCNNA) to process more than 1200 SAR images collected over the GOM. We quantified more than 900 individual seep formations distributed along the continental shelf and in deep water. Comparison of the geophysical anomalies with the SAR oil slick targets shows good general agreement between the distributions of the two indicators. However, there are far fewer active oil slicks than geophysical anomalies, most of which are probably associated with gas seepage. By examining several sites where the location of active venting can be determined by submersibles observations, we found that the active oily vents are often spatially offset from the most intense geophysical targets (i.e. GC600, GC767, GC204, etc). In addition to the displacement of the oil by deep sea currents, we propose that during the 100K years of activity, the location of the vents on the seafloor probably migrate as carbonate cementation reduces the permeability of the upper sediment. Many of the geophysical targets may represent

  4. 3D imaging of the Corinth rift from a new passive seismic tomography and receiver function analysis

    NASA Astrophysics Data System (ADS)

    Godano, Maxime; Gesret, Alexandrine; Noble, Mark; Lyon-Caen, Hélène; Gautier, Stéphanie; Deschamps, Anne

    2016-04-01

    The Corinth Rift is the most seismically active zone in Europe. The area is characterized by very localized NS extension at a rate of ~ 1.5cm/year, the occurrence of frequent and intensive microseismic crises and occasional moderate to large earthquakes like in 1995 (Mw=6.1). Since the year 2000, the Corinth Rift Laboratory (CRL, http://crlab.eu) consisting in a multidisciplinary natural observatory, aims at understanding the mechanics of faulting and earthquake nucleation in the Rift. Recent studies have improved our view about fault geometry and mechanics within CRL, but there is still a critical need for a better knowledge of the structure at depth both for the accuracy of earthquake locations and for mechanical interpretation of the seismicity. In this project, we aim to analyze the complete seismological database (13 years of recordings) of CRL by using recently developed methodologies of structural imaging, in order to determine at the same time and with high resolution, the local 3D structure and the earthquake locations. We perform an iterative joint determination of 3D velocity model and earthquake coordinates. In a first step, P and S velocity models are determined using first arrival time tomography method proposed by Taillandier et al. (2009). It consists in the minimization of the cost function between observed and theoretical arrival times which is achieved by the steepest descent method (e.g. Tarantola 1987). This latter requires computing the gradient of the cost function by using the adjoint state method (Chavent 1974). In a second step, earthquakes are located in the new velocity model with a non-linear inversion method based on a Bayesian formulation (Gesret et al. 2015). Step 1 and 2 are repeated until the cost function no longer decreases. We present preliminary results consisting in: (1) the adjustement of a 1D velocity model that is used as initial model of the 3D tomography and (2) a first attempt of the joint determination of 3D velocity

  5. Rock formation characterization for carbon dioxide geosequestration: 3D seismic amplitude and coherency anomalies, and seismic petrophysical facies classification, Wellington and Anson-Bates Fields, Kansas, USA

    NASA Astrophysics Data System (ADS)

    Ohl, Derek; Raef, Abdelmoneam

    2014-04-01

    Higher resolution rock formation characterization is of paramount priority, amid growing interest in injecting carbon dioxide, CO2, into subsurface rock formations of depeleting/depleted hydrocarbon reservoirs or saline aquifers in order to reduce emissions of greenhouse gases. In this paper, we present a case study for a Mississippian carbonate characterization integrating post-stack seismic attributes, well log porosities, and seismic petrophysical facies classification. We evaluated changes in petrophysical lithofacies and reveal structural facies-controls in the study area. Three cross-plot clusters in a plot of well log porosity and acoustic impedance corroborated a Neural Network petrophysical facies classification, which was based on training and validation utilizing three petrophysically-different wells and three volume seismic attributes, extracted from a time window including the wavelet of the reservoir-top reflection. Reworked lithofacies along small-throw faults has been revealed based on comparing coherency and seismic petrophysical facies. The main objective of this study is to put an emphasis on reservoir characterization that is both optimized for and subsequently benefiting from pilot tertiary CO2 carbon geosequestration in a depleting reservoir and also in the deeper saline aquifer of the Arbuckle Group, south central Kansas. The 3D seismic coherency attribute, we calculated from a window embracing the Mississippian top reflection event, indicated anomalous features that can be interpreted as a change in lithofacies or faulting effect. An Artificial Neural Network (ANN) lithofacies modeling has been used to better understand these subtle features, and also provide petrophysical classes, which will benefit flow-simulation modeling and/or time-lapse seismic monitoring feasibility analysis. This paper emphasizes the need of paying greater attention to small-scale features when embarking upon characterization of a reservoir or saline-aquifer for CO2

  6. Land 3D-seismic data: Preprocessing quality control utilizing survey design specifications, noise properties, normal moveout, first breaks, and offset

    USGS Publications Warehouse

    Raef, A.

    2009-01-01

    The recent proliferation of the 3D reflection seismic method into the near-surface area of geophysical applications, especially in response to the emergence of the need to comprehensively characterize and monitor near-surface carbon dioxide sequestration in shallow saline aquifers around the world, justifies the emphasis on cost-effective and robust quality control and assurance (QC/QA) workflow of 3D seismic data preprocessing that is suitable for near-surface applications. The main purpose of our seismic data preprocessing QC is to enable the use of appropriate header information, data that are free of noise-dominated traces, and/or flawed vertical stacking in subsequent processing steps. In this article, I provide an account of utilizing survey design specifications, noise properties, first breaks, and normal moveout for rapid and thorough graphical QC/QA diagnostics, which are easy to apply and efficient in the diagnosis of inconsistencies. A correlated vibroseis time-lapse 3D-seismic data set from a CO2-flood monitoring survey is used for demonstrating QC diagnostics. An important by-product of the QC workflow is establishing the number of layers for a refraction statics model in a data-driven graphical manner that capitalizes on the spatial coverage of the 3D seismic data. ?? China University of Geosciences (Wuhan) and Springer-Verlag GmbH 2009.

  7. Computational modeling of RNA 3D structures and interactions.

    PubMed

    Dawson, Wayne K; Bujnicki, Janusz M

    2016-04-01

    RNA molecules have key functions in cellular processes beyond being carriers of protein-coding information. These functions are often dependent on the ability to form complex three-dimensional (3D) structures. However, experimental determination of RNA 3D structures is difficult, which has prompted the development of computational methods for structure prediction from sequence. Recent progress in 3D structure modeling of RNA and emerging approaches for predicting RNA interactions with ions, ligands and proteins have been stimulated by successes in protein 3D structure modeling.

  8. San Francisco Bay test case for 3-D model verification

    USGS Publications Warehouse

    Smith, Peter E.

    1994-01-01

    This paper describes a field test case for 3-D hydrodynamic model verification using data from Carquinez Strait in San Francisco Bay, California. It will be disseminated by the ASCE Computational Hydraulics task committee on 3-D Free-Surface Hydrodynamic Model Verifications during late 1994.

  9. Analysis of Paleokarst Sinkholes in the Arkoma Basin using 3-D Seismic

    NASA Astrophysics Data System (ADS)

    Kumbalek, Michael

    Paleokarst features are important to understand, both with regards to research geologists and to the petroleum industry. In terms of geology, understanding paleokarst features can yield more information about the depositional and surface environments of past times, and how diagenetic alteration affected the environment during the formation of karst features. In the petroleum industry, paleokarst features can have positive or negative consequence resulting in a potential reservoir with enhanced porosity due to the paleokarst features, or as a geo-hazard to prepare for or avoid when drilling. Inspired by issues faced when drilling in the Ft. Worth basin, this study utilizes multiple 3-D seismic surveys and subsurface well control to map paleokarsts within the Viola Limestone in the Arkoma Basin. Calculated seismic attribute volumes used to identify paleokarst sinkholes within the Viola Group include coherency and curvature attributes. ImageJ software was used to aid in counting and measuring paleokarst sinkholes identified using seismic mapping, coherency, and curvature attribute volumes. In addition to mapping, a cumulative distribution plot was produced from the diameters of the seismically mapped paleokarst sinkholes, allowing for an estimate to be made as to what the total amount of paleokarst sinkholes are within the study area. The methods detailed in this study proved to be effective in mapping and analyzing paleokarst sinkholes within the Viola Group. The paleokarst sinkholes mapped were determined to have been formed on the outer edge of the Southern Oklahoma aulacogen, as a result of the Sylvan/Viola unconformity. In addition to this, it has been determined that these paleokarst sinkholes are linked in formation to visually similar paleokarst sinkholes located in the Ellenburger Group in the Fort Worth Basin.

  10. An Automatic Registration Algorithm for 3D Maxillofacial Model

    NASA Astrophysics Data System (ADS)

    Qiu, Luwen; Zhou, Zhongwei; Guo, Jixiang; Lv, Jiancheng

    2016-09-01

    3D image registration aims at aligning two 3D data sets in a common coordinate system, which has been widely used in computer vision, pattern recognition and computer assisted surgery. One challenging problem in 3D registration is that point-wise correspondences between two point sets are often unknown apriori. In this work, we develop an automatic algorithm for 3D maxillofacial models registration including facial surface model and skull model. Our proposed registration algorithm can achieve a good alignment result between partial and whole maxillofacial model in spite of ambiguous matching, which has a potential application in the oral and maxillofacial reparative and reconstructive surgery. The proposed algorithm includes three steps: (1) 3D-SIFT features extraction and FPFH descriptors construction; (2) feature matching using SAC-IA; (3) coarse rigid alignment and refinement by ICP. Experiments on facial surfaces and mandible skull models demonstrate the efficiency and robustness of our algorithm.

  11. Interactive mapping on 3-D terrain models

    NASA Astrophysics Data System (ADS)

    Bernardin, T.; Cowgill, E.; Gold, R.; Hamann, B.; Kreylos, O.; Schmitt, A.

    2006-10-01

    We present an interactive, real-time mapping system for use with digital elevation models and remotely sensed multispectral imagery that aids geoscientists in the creation and interpretation of geologic/neotectonic maps at length scales of 10 m to 1000 km. Our system provides a terrain visualization of the surface of the Earth or other terrestrial planets by displaying a virtual terrain model generated from a digital elevation model overlain by a color texture generated from orthophotos or satellite imagery. We use a quadtree-based, multiresolution display method to render in real time high-resolution virtual terrain models that span large spatial regions. The system allows users to measure the orientations of geologic surfaces and record their observations by drawing lines directly on the virtual terrain model. In addition, interpretive surfaces can be generated from these drawings and displayed to facilitate understanding of the three-dimensional geometry of geologic surfaces. The main strength of our system is the combination of real-time rendering and interactive mapping performed directly on the virtual terrain model with the ability to navigate the scene while changing viewpoints arbitrarily during mapping. User studies and comparisons with commercially available mapping software show that our system improves mapping accuracy and efficiency and also yields observations that cannot be made with existing systems.

  12. 3-D model-based Bayesian classification

    SciTech Connect

    Soenneland, L.; Tenneboe, P.; Gehrmann, T.; Yrke, O.

    1994-12-31

    The challenging task of the interpreter is to integrate different pieces of information and combine them into an earth model. The sophistication level of this earth model might vary from the simplest geometrical description to the most complex set of reservoir parameters related to the geometrical description. Obviously the sophistication level also depend on the completeness of the available information. The authors describe the interpreter`s task as a mapping between the observation space and the model space. The information available to the interpreter exists in observation space and the task is to infer a model in model-space. It is well-known that this inversion problem is non-unique. Therefore any attempt to find a solution depend son constraints being added in some manner. The solution will obviously depend on which constraints are introduced and it would be desirable to allow the interpreter to modify the constraints in a problem-dependent manner. They will present a probabilistic framework that gives the interpreter the tools to integrate the different types of information and produce constrained solutions. The constraints can be adapted to the problem at hand.

  13. Extending 3D city models with legal information

    NASA Astrophysics Data System (ADS)

    Frank, A. U.; Fuhrmann, T.; Navratil, G.

    2012-10-01

    3D city models represent existing physical objects and their topological and functional relations. In everyday life the rights and responsibilities connected to these objects, primarily legally defined rights and obligations but also other socially and culturally established rights, are of importance. The rights and obligations are defined in various laws and it is often difficult to identify the rules applicable for a certain case. The existing 2D cadastres show civil law rights and obligations and plans to extend them to provide information about public law restrictions for land use are in several countries under way. It is tempting to design extensions to the 3D city models to provide information about legal rights in 3D. The paper analyses the different types of information that are needed to reduce conflicts and to facilitate decisions about land use. We identify the role 3D city models augmented with planning information in 3D can play, but do not advocate a general conversion from 2D to 3D for the legal cadastre. Space is not anisotropic and the up/down dimension is practically very different from the two dimensional plane - this difference must be respected when designing spatial information systems. The conclusions are: (1) continue the current regime for ownership of apartments, which is not ownership of a 3D volume, but co-ownership of a building with exclusive use of some rooms; such exclusive use rights could be shown in a 3D city model; (2) ownership of 3D volumes for complex and unusual building situations can be reported in a 3D city model, but are not required everywhere; (3) indicate restrictions for land use and building in 3D city models, with links to the legal sources.

  14. Opportunity Landing Spot Panorama (3-D Model)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The rocky outcrop traversed by the Mars Exploration Rover Opportunity is visible in this three-dimensional model of the rover's landing site. Opportunity has acquired close-up images along the way, and scientists are using the rover's instruments to closely examine portions of interest. The white fragments that look crumpled near the center of the image are portions of the airbags. Distant scenery is displayed on a spherical backdrop or 'billboard' for context. Artifacts near the top rim of the crater are a result of the transition between the three-dimensional model and the billboard. Portions of the terrain model lacking sufficient data appear as blank spaces or gaps, colored reddish-brown for better viewing. This image was generated using special software from NASA's Ames Research Center and a mosaic of images taken by the rover's panoramic camera.

    [figure removed for brevity, see original site] Click on image for larger view

    The rocky outcrop traversed by the Mars Exploration Rover Opportunity is visible in this zoomed-in portion of a three-dimensional model of the rover's landing site. Opportunity has acquired close-up images along the way, and scientists are using the rover's instruments to closely examine portions of interest. The white fragments that look crumpled near the center of the image are portions of the airbags. Distant scenery is displayed on a spherical backdrop or 'billboard' for context. Artifacts near the top rim of the crater are a result of the transition between the three-dimensional model and the billboard. Portions of the terrain model lacking sufficient data appear as blank spaces or gaps, colored reddish-brown for better viewing. This image was generated using special software from NASA's Ames Research Center and a mosaic of images taken by the rover's panoramic camera.

  15. Venusian Applications of 3D Convection Modeling

    NASA Technical Reports Server (NTRS)

    Bonaccorso, Timary Annie

    2011-01-01

    This study models mantle convection on Venus using the 'cubed sphere' code OEDIPUS, which models one-sixth of the planet in spherical geometry. We are attempting to balance internal heating, bottom mantle viscosity, and temperature difference across Venus' mantle, in order to create a realistic model that matches with current planetary observations. We also have begun to run both lower and upper mantle simulations to determine whether layered (as opposed to whole-mantle) convection might produce more efficient heat transfer, as well as to model coronae formation in the upper mantle. Upper mantle simulations are completed using OEDIPUS' Cartesian counterpart, JOCASTA. This summer's central question has been how to define a mantle plume. Traditionally, we have defined a hot plume the region with temperature at or above 40% of the difference between the maximum and horizontally averaged temperature, and a cold plume as the region with 40% of the difference between the minimum and average temperature. For less viscous cases (1020 Pa?s), the plumes generated by that definition lacked vigor, displaying buoyancies 1/100th of those found in previous, higher viscosity simulations (1021 Pa?s). As the mantle plumes with large buoyancy flux are most likely to produce topographic uplift and volcanism, the low viscosity cases' plumes may not produce observable deformation. In an effort to eliminate the smallest plumes, we experimented with different lower bound parameters and temperature percentages.

  16. RELAP5-3D Compressor Model

    SciTech Connect

    James E. Fisher; Cliff B. Davis; Walter L. Weaver

    2005-06-01

    A compressor model has been implemented in the RELAP5-3D© code. The model is similar to that of the existing pump model, and performs the same function on a gas as the pump performs on a single-phase or two-phase fluid. The compressor component consists of an inlet junction and a control volume, and optionally, an outlet junction. This feature permits cascading compressor components in series. The equations describing the physics of the compressor are derived from first principles. These equations are used to obtain the head, the torque, and the energy dissipation. Compressor performance is specified using a map, specific to the design of the machine, in terms of the ratio of outlet-to-inlet total (or stagnation) pressure and adiabatic efficiency as functions of rotational velocity and flow rate. The input quantities are specified in terms of dimensionless variables, which are corrected to stagnation density and stagnation sound speed. A small correction was formulated for the input of efficiency to account for the error introduced by assumption of constant density when integrating the momentum equation. Comparison of the results of steady-state operation of the compressor model to those of the MIT design calculation showed excellent agreement for both pressure ratio and power.

  17. High-resolution 3D seismic investigation of giant seafloor craters in the Barents Sea

    NASA Astrophysics Data System (ADS)

    Waage, Malin; Bünz, Stefan; Andreassen, Karin

    2016-04-01

    Multiple giant craters exist on the seafloor in an area of ~ 100 km2 east of Bear Island Trough in the west-central Barents Sea. It has been hypothesized that these craters might have been caused by gas eruptions following the last deglaciation. Gas seepage from the seafloor occurs abundantly in this area. The crater area is still likely to represent one of the largest hot-spots for shallow marine methane release in the arctic. In summer 2015, we acquired high-resolution P-Cable 3D seismic data in this area covering several of the craters and their associated pingo structures. Due to the shallow and hard Triassic bedrock, penetration of the seismic signals is limited to approximately 450 ms bsf. The crater structures are up to 1 km wide and 40 m deep. Pingo structures occur on the rim of some of the craters and are up to 700 m wide and up to 15 m high above the surrounding seafloor. The 3D seismic data reveals faults, fracture networks and weakness zone that resemble pipes or similar vertical, focused fluid-flow structures in the Triassic sedimentary rocks below the craters. The principal orientation of the faults is in a ~ NW-SE direction that coincides with regional faulting from Permo-Triassic extension. The seismic data also show high-amplitude anomalies beneath some of representing shallow gas accumulations that might be the intermediate source of the gas seepage. This might suggest that craters are caused by high pressured gas that migrated from deeper petroleum systems and accumulated in the shallow Triassic rocks during the last glaciation. Previous work indicate that craters of similar size are likely a cause of enormous blow-outs of gas. Our study discusses the formation mechanisms and timing of these potential blow-out craters and whether they formed during the last deglaciation, when this area was likely quite unstable as severe glacial erosion caused localized high isostatic rebound rates here. We also investigate the role of gas hydrates that might

  18. Testing long-period ground-motion simulations of scenario earthquakes using the Mw 7.2 El Mayor-Cucapah mainshock: Evaluation of finite-fault rupture characterization and 3D seismic velocity models

    USGS Publications Warehouse

    Graves, Robert W.; Aagaard, Brad T.

    2011-01-01

    Using a suite of five hypothetical finite-fault rupture models, we test the ability of long-period (T>2.0 s) ground-motion simulations of scenario earthquakes to produce waveforms throughout southern California consistent with those recorded during the 4 April 2010 Mw 7.2 El Mayor-Cucapah earthquake. The hypothetical ruptures are generated using the methodology proposed by Graves and Pitarka (2010) and require, as inputs, only a general description of the fault location and geometry, event magnitude, and hypocenter, as would be done for a scenario event. For each rupture model, two Southern California Earthquake Center three-dimensional community seismic velocity models (CVM-4m and CVM-H62) are used, resulting in a total of 10 ground-motion simulations, which we compare with recorded ground motions. While the details of the motions vary across the simulations, the median levels match the observed peak ground velocities reasonably well, with the standard deviation of the residuals generally within 50% of the median. Simulations with the CVM-4m model yield somewhat lower variance than those with the CVM-H62 model. Both models tend to overpredict motions in the San Diego region and underpredict motions in the Mojave desert. Within the greater Los Angeles basin, the CVM-4m model generally matches the level of observed motions, whereas the CVM-H62 model tends to overpredict the motions, particularly in the southern portion of the basin. The variance in the peak velocity residuals is lowest for a rupture that has significant shallow slip (<5 km depth), whereas the variance in the residuals is greatest for ruptures with large asperities below 10 km depth. Overall, these results are encouraging and provide confidence in the predictive capabilities of the simulation methodology, while also suggesting some regions in which the seismic velocity models may need improvement.

  19. Global Magnetospheric Modeling of 3D Reconnection

    NASA Technical Reports Server (NTRS)

    Spicer, Daniel S.

    1999-01-01

    A review of approaches to the global modeling of the terrestrial magnetosphere, how these approaches are utilized to interpret satellite data, and how these approaches have been successful at predicting magnetospheric phenomena will be presented. In addition, the importance of the ionospheric boundary and its effect on the globally topology of the magnetospheric magnetic field will be reviewed. In particular, numerical results that are rapidly changing our view of magnetospheric reconnection within the magnetospheric magnetic field will be discussed.

  20. 3D time-lapse seismic traveltime tomography for detecting near surface velocity variations: a case study from the Ketzin CO2 storage pilot site

    NASA Astrophysics Data System (ADS)

    Zhang, Fengjiao; Juhlin, Christopher; Huang, Fei; Lüth, Stefan

    2016-04-01

    Time-lapse seismic methods are an important tool for monitoring CO2 migration and storage in geological formations. Near surface variations are one of the major problems which may introduce time-lapse noise in the application of land based seismic monitoring. Conventional reflection seismic methods have difficulties in imaging near surface structures (10-30 m depth) due to the limitation of the methods themselves. Traveltime tomography is a commonly used method to reconstruct the subsurface velocity model. It can often provide extra information on near surface structures which is difficult to obtain by the conventional reflection seismic method. In this study, we apply traveltime tomography to 3D time-lapse seismic data sets acquired from at the Ketzin CO2 storage site. We also test different inversion strategies for traveltime tomography to investigate which one is more suitable for this case study. The results show good correlation with near surface variations obtained by other studies.

  1. Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data

    SciTech Connect

    Barbara Romanowicz; Mark Panning

    2005-04-23

    Adequate path calibrations are crucial for improving the accuracy of seismic event location and origin time, size, and mechanism, as required for CTBT monitoring. There is considerable information on structure in broadband seismograms that is currently not fully utilized. The limitations have been largely theoretical. the development and application to solid earth problems of powerful numerical techniques, such as the Spectral Element Method (SEM), has opened a new era, and theoretically, it should be possible to compute the complete predicted wavefield accurately without any restrictions on the strength or spatial extent of heterogeneity. This approach requires considerable computational power, which is currently not fully reachable in practice. We propose an approach which relies on a cascade of increasingly accurate theoretical approximations for the computation of the seismic wavefield to develop a model of regional structure for the area of Eurasia located between longitudes of 30 and 150 degrees E, and latitudes of -10 to 60 degrees North. The selected area is particularly suitable for the purpose of this experiment, as it is highly heterogeneous, presenting a challenge for calibration purposes, but it is well surrounded by earthquake sources and, even though they are sparsely distributed, a significant number of high quality broadband digital stations exist, for which data are readily accessible through IRIS (Incorporated Research Institutions for Seismology) and the FDSN (Federation of Digital Seismic Networks). The starting models used will be a combination of a-priori 3D models recently developed for this region, combining various geophysical and seismological data, and a major goal of this study will be to refine these models so as to fit a variety of seismic waveforms and phases.

  2. Estimating the composition of hydrates from a 3D seismic dataset near Penghu Canyon on Chinese passive margin offshore Taiwan

    NASA Astrophysics Data System (ADS)

    Chi, Wu-Cheng

    2016-04-01

    A bottom-simulating reflector (BSR), representing the base of the gas hydrate stability zone, can be used to estimate geothermal gradients under seafloor. However, to derive temperature estimates at the BSR, the correct hydrate composition is needed to calculate the phase boundary. Here we applied the method by Minshull and Keddie to constrain the hydrate composition and the pore fluid salinity. We used a 3D seismic dataset offshore SW Taiwan to test the method. Different from previous studies, we have considered the effects of 3D topographic effects using finite element modelling and also depth-dependent thermal conductivity. Using a pore water salinity of 2% at the BSR depth as found from the nearby core samples, we successfully used 99% methane and 1% ethane gas hydrate phase boundary to derive a sub-bottom depth vs. temperature plot which is consistent with the seafloor temperature from in-situ measurements. The results are also consistent with geochemical analyses of the pore fluids. The derived regional geothermal gradient is 40.1oC/km, which is similar to 40oC/km used in the 3D finite element modelling used in this study. This study is among the first documented successful use of Minshull and Keddie's method to constrain seafloor gas hydrate composition.

  3. Modeling 3D facial shape from DNA.

    PubMed

    Claes, Peter; Liberton, Denise K; Daniels, Katleen; Rosana, Kerri Matthes; Quillen, Ellen E; Pearson, Laurel N; McEvoy, Brian; Bauchet, Marc; Zaidi, Arslan A; Yao, Wei; Tang, Hua; Barsh, Gregory S; Absher, Devin M; Puts, David A; Rocha, Jorge; Beleza, Sandra; Pereira, Rinaldo W; Baynam, Gareth; Suetens, Paul; Vandermeulen, Dirk; Wagner, Jennifer K; Boster, James S; Shriver, Mark D

    2014-03-01

    Human facial diversity is substantial, complex, and largely scientifically unexplained. We used spatially dense quasi-landmarks to measure face shape in population samples with mixed West African and European ancestry from three locations (United States, Brazil, and Cape Verde). Using bootstrapped response-based imputation modeling (BRIM), we uncover the relationships between facial variation and the effects of sex, genomic ancestry, and a subset of craniofacial candidate genes. The facial effects of these variables are summarized as response-based imputed predictor (RIP) variables, which are validated using self-reported sex, genomic ancestry, and observer-based facial ratings (femininity and proportional ancestry) and judgments (sex and population group). By jointly modeling sex, genomic ancestry, and genotype, the independent effects of particular alleles on facial features can be uncovered. Results on a set of 20 genes showing significant effects on facial features provide support for this approach as a novel means to identify genes affecting normal-range facial features and for approximating the appearance of a face from genetic markers.

  4. Modeling 3D Facial Shape from DNA

    PubMed Central

    Claes, Peter; Liberton, Denise K.; Daniels, Katleen; Rosana, Kerri Matthes; Quillen, Ellen E.; Pearson, Laurel N.; McEvoy, Brian; Bauchet, Marc; Zaidi, Arslan A.; Yao, Wei; Tang, Hua; Barsh, Gregory S.; Absher, Devin M.; Puts, David A.; Rocha, Jorge; Beleza, Sandra; Pereira, Rinaldo W.; Baynam, Gareth; Suetens, Paul; Vandermeulen, Dirk; Wagner, Jennifer K.; Boster, James S.; Shriver, Mark D.

    2014-01-01

    Human facial diversity is substantial, complex, and largely scientifically unexplained. We used spatially dense quasi-landmarks to measure face shape in population samples with mixed West African and European ancestry from three locations (United States, Brazil, and Cape Verde). Using bootstrapped response-based imputation modeling (BRIM), we uncover the relationships between facial variation and the effects of sex, genomic ancestry, and a subset of craniofacial candidate genes. The facial effects of these variables are summarized as response-based imputed predictor (RIP) variables, which are validated using self-reported sex, genomic ancestry, and observer-based facial ratings (femininity and proportional ancestry) and judgments (sex and population group). By jointly modeling sex, genomic ancestry, and genotype, the independent effects of particular alleles on facial features can be uncovered. Results on a set of 20 genes showing significant effects on facial features provide support for this approach as a novel means to identify genes affecting normal-range facial features and for approximating the appearance of a face from genetic markers. PMID:24651127

  5. Modelling Polymer Deformation during 3D Printing

    NASA Astrophysics Data System (ADS)

    McIlroy, Claire; Olmsted, Peter

    Three-dimensional printing has the potential to transform manufacturing processes, yet improving the strength of printed parts, to equal that of traditionally-manufactured parts, remains an underlying issue. The fused deposition modelling technique involves melting a thermoplastic, followed by layer-by-layer extrusion to fabricate an object. The key to ensuring strength at the weld between layers is successful inter-diffusion. However, prior to welding, both the extrusion process and the cooling temperature profile can significantly deform the polymer micro-structure and, consequently, how well the polymers are able to ``re-entangle'' across the weld. In particular, polymer alignment in the flow can cause de-bonding of the layers and create defects. We have developed a simple model of the non-isothermal extrusion process to explore the effects that typical printing conditions and material rheology have on the conformation of a polymer melt. In particular, we incorporate both stretch and orientation using the Rolie-Poly constitutive equation to examine the melt structure as it flows through the nozzle, the subsequent alignment with the build plate and the resulting deformation due to the fixed nozzle height, which is typically less than the nozzle radius.

  6. Image based 3D city modeling : Comparative study

    NASA Astrophysics Data System (ADS)

    Singh, S. P.; Jain, K.; Mandla, V. R.

    2014-06-01

    3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can't do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city

  7. NoSQL Based 3D City Model Management System

    NASA Astrophysics Data System (ADS)

    Mao, B.; Harrie, L.; Cao, J.; Wu, Z.; Shen, J.

    2014-04-01

    To manage increasingly complicated 3D city models, a framework based on NoSQL database is proposed in this paper. The framework supports import and export of 3D city model according to international standards such as CityGML, KML/COLLADA and X3D. We also suggest and implement 3D model analysis and visualization in the framework. For city model analysis, 3D geometry data and semantic information (such as name, height, area, price and so on) are stored and processed separately. We use a Map-Reduce method to deal with the 3D geometry data since it is more complex, while the semantic analysis is mainly based on database query operation. For visualization, a multiple 3D city representation structure CityTree is implemented within the framework to support dynamic LODs based on user viewpoint. Also, the proposed framework is easily extensible and supports geoindexes to speed up the querying. Our experimental results show that the proposed 3D city management system can efficiently fulfil the analysis and visualization requirements.

  8. Modeling cell migration in 3D: Status and challenges.

    PubMed

    Rangarajan, Rajagopal; Zaman, Muhammad H

    2008-01-01

    Cell migration is a multi-scale process that integrates signaling, mechanics and biochemical reaction kinetics. Various mathematical models accurately predict cell migration on 2D surfaces, but are unable to capture the complexities of 3D migration. Additionally, quantitative 3D cell migration models have been few and far between. In this review we look and characterize various mathematical models available in literature to predict cell migration in 3D matrices and analyze their strengths and possible changes to these models that could improve their predictive capabilities.

  9. 3D PIC Modeling of Microcavity Discharge

    NASA Astrophysics Data System (ADS)

    Hopkins, Matthew; Manginell, Ronald; Moore, Christopher; Yee, Benjamin; Moorman, Matthew

    2015-09-01

    We present a number of techniques and challenges in simulating the transient behavior of a microcavity discharge. Our microcavities are typically cylindrical with diameters approximately 50 - 100 μm, heights of 50 - 200 μm, pressure near atmospheric, and operate at a few hundred volts. We employ a fully kinetic simulation methodology, the Particle-in-Cell (PIC) method, with interparticle collisions handled via methods based on direct simulation Monte Carlo (DSMC). In particular, we explicitly include kinetic electrons. Some of the challenges we encounter include variations in number densities, external circuit coupling, and time step resolution constraints. By employing dynamic particle weighting (particle weights vary over time by species and location) we can mitigate some of the challenges modeling systems with 107 variations in number densities. Smoothing mechanisms have been used to attempt to mitigate external circuit response. We perform our simulations on hundreds or thousands of processing cores to accommodate the computational work inherent in using relatively small time step sizes (e.g., 50 fs for a 100 ns calculation). In addition, particle weighting issues inherent to three-dimensional low temperature plasma systems will be mentioned. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under Contract DE-AC04-94AL85000.

  10. Kongsfjorden-MIKE 3D model

    NASA Astrophysics Data System (ADS)

    Przyborska, Anna; Kosecki, Szymon; Jakacki, Jaromir

    2014-05-01

    Kongsfjorden is a West Svalbard fjord with a surface area of about 210 km2. It is obvious that the depths of the outer and central basins are influenced by the open sea, under influence of West Spitsbergen Current (WSC), which curry out warm Atlantic water and cold East Spitsbergen Current, while the shallower, inner basin has a large glacial outflow and its maximum depths do not exceed 100 m. Freshwater stored in Spitsbergen glaciers have strong influence on local hydrology and physical fjord conditions. Both, local and shelf conditions have impact on state of the fjord. External forces like tides, velocities at the boundary and atmospheric forces together with sources of cold and dens fresh water in the fjords will give reliable representation of physical conditions in Kongsfjorden. Modeling could help to solve this problem and we have hope that we find answer which one is the most important for local conditions in fjord. Calculations of balances between cold fresh water and warm and salt will provide additional information that could help to answer the main question of the GAME (Growing of the Arctic Marine Ecosystem) project - what is the reaction of physically controlled Arctic marine ecosystem to temperature rise.

  11. Refining seismic parameters in low seismicity areas by 3D trenching: The Alhama de Murcia fault, SE Iberia

    NASA Astrophysics Data System (ADS)

    Ferrater, Marta; Ortuño, Maria; Masana, Eulàlia; Pallàs, Raimon; Perea, Hector; Baize, Stephane; García-Meléndez, Eduardo; Martínez-Díaz, José J.; Echeverria, Anna; Rockwell, Thomas K.; Sharp, Warren D.; Medialdea, Alicia; Rhodes, Edward J.

    2016-06-01

    Three-dimensional paleoseismology in strike-slip faults with slip rates less than 1 mm per year involves a great methodological challenge. We adapted 3D trenching to track buried channels offset by the Alhama de Murcia seismogenic left-lateral strike-slip fault (SE Iberia). A fault net slip of 0.9 ± 0.1 mm/yr was determined using statistical analysis of piercing lines for one buried channel, whose age is constrained between 15.2 ± 1.1 ka and 21.9-22.3 cal BP. This value is larger and more accurate than the previously published slip rates for this fault. The minimum number of five paleo-earthquakes identified since the deposition of dated layers suggests a maximum average recurrence interval of approximately 5 ka. The combination of both seismic parameters yields a maximum slip per event between 5.3 and 6.3 m. We show that accurately planned trenching strategies and data processing may be key to obtaining robust paleoseismic parameters in low seismicity areas.

  12. 3D model retrieval method based on mesh segmentation

    NASA Astrophysics Data System (ADS)

    Gan, Yuanchao; Tang, Yan; Zhang, Qingchen

    2012-04-01

    In the process of feature description and extraction, current 3D model retrieval algorithms focus on the global features of 3D models but ignore the combination of global and local features of the model. For this reason, they show less effective performance to the models with similar global shape and different local shape. This paper proposes a novel algorithm for 3D model retrieval based on mesh segmentation. The key idea is to exact the structure feature and the local shape feature of 3D models, and then to compares the similarities of the two characteristics and the total similarity between the models. A system that realizes this approach was built and tested on a database of 200 objects and achieves expected results. The results show that the proposed algorithm improves the precision and the recall rate effectively.

  13. Considerations on the Use of 3-D Geophysical Models to Predict Test Ban Monitoring Observables

    SciTech Connect

    Harris, D B; Zucca, J J; McCallen, D B; Pasyanos, M E; Flanagan, M P; Myers, S C; Walter, W R; Rodgers, A J; Harben, P E

    2007-07-09

    The use of 3-D geophysical models to predict nuclear test ban monitoring observables (phase travel times, amplitudes, dispersion, etc.) is widely anticipated to provide improvements in the basic seismic monitoring functions of detection, association, location, discrimination and yield estimation. A number of questions arise when contemplating a transition from 1-D, 2-D and 2.5-D models to constructing and using 3-D models, among them: (1) Can a 3-D geophysical model or a collection of 3-D models provide measurably improved predictions of seismic monitoring observables over existing 1-D models, or 2-D and 2 1/2-D models currently under development? (2) Is a single model that can predict all observables achievable, or must separate models be devised for each observable? How should joint inversion of disparate observable data be performed, if required? (3) What are the options for model representation? Are multi-resolution models essential? How does representation affect the accuracy and speed of observable predictions? (4) How should model uncertainty be estimated, represented and how should it be used? Are stochastic models desirable? (5) What data types should be used to construct the models? What quality control regime should be established? (6) How will 3-D models be used in operations? Will significant improvements in the basic monitoring functions result from the use of 3-D models? Will the calculation of observables through 3-D models be fast enough for real-time use or must a strategy of pre-computation be employed? (7) What are the theoretical limits to 3-D model development (resolution, uncertainty) and performance in predicting monitoring observables? How closely can those limits be approached with projected data availability, station distribution and inverse methods? (8) What priorities should be placed on the acquisition of event ground truth information, deployment of new stations, development of new inverse techniques, exploitation of large

  14. NACr14: A 3D model for the crustal structure of the North American Continent

    NASA Astrophysics Data System (ADS)

    Tesauro, Magdala; Kaban, Mikhail K.; Mooney, Walter D.; Cloetingh, Sierd

    2014-09-01

    Based on the large number of crustal seismic experiments carried out in the last decades we create NACr14, a 3D crustal model of the North American continent at a resolution of 1° × 1°. We present maps of thickness and average velocities of the main layers that comprise the North American crystalline crust, obtained from the most recent seismic crustal models within the USGS crustal structure database. However, the crustal data are unevenly distributed and in some cases discrepancies exist between published models. In order to construct a consistent 3D crustal model with three layers in the crystalline crust, we refrained from a direct interpolation of the crustal seismic parameters in the database. Instead, we implemented the following sequence of steps: 1. Definition of the geometry of the main tectonic provinces of North America; 2. Selection and evaluation of the reliability of seismic crustal models in the database; 3. Estimation of the P-wave seismic velocity and thickness of the upper, middle and lower crust for each tectonic province; 4. Estimation of the interpolated Pn velocity distribution. The resulting average velocity of the crystalline crust is mostly consistent with that of the seismic points. The main variations of the structure of the crystalline crust of North America displayed in the model can be related to its tectonic evolution. The model, available in a digital form, can be used in various geophysical applications, such as the correction for the crustal effects in gravity and seismic tomography and models of dynamic topography, in order to detect heterogeneities characterizing the underlying upper mantle.

  15. 3D Euler deconvolution in the New Madrid seismic zone (eastern US)

    NASA Astrophysics Data System (ADS)

    Arroucau, P.; Vlahovic, G.; Powell, C. A.

    2011-12-01

    The seismicity of intraplate continental interiors is one of the most challenging -though a bit overlooked- research topics in seismology. The most famous of those is undoubtedly the New Madrid seismic zone (NMSZ), named after the city of New Madrid, Missouri, that was destroyed by one of the three M>7.0 earthquakes that occurred in central United States during the winter 1811-1812. After two centuries, there is still no consensus about what caused that crisis, how it is related to the current moderate magnitude activity of that region, and how likely it is that similarly large events will occur again in a near future in the NMSZ or in its vicinity. As often in such geodynamic settings, a key question is the role of structural reactivation in the current stress field. As modern earthquakes of the NMSZ mostly occur in the Precambrian basement, below the Mississippi embayment sedimentary cover and at such depths that no deformation is observed at the surface, almost no direct observation is available about faults segments that would be responsible for that seismicity. Yet the activity of the NMSZ is known to coincide with a Precambrian failed rift, the Reelfoot rift, whose geometry is mostly inferred from potential field data. In this work, we apply 3D Euler deconvolution to the total magnetic intensity field of the NMSZ. Euler deconvolution is a technique commonly used in exploration geophysics to determine the depth of magnetic sources and more generally to produce depth-to-basement maps and image deep structures buried beneath non-magnetic sedimentary cover. We obtain basement topography maps that we compare with previously published maps and with the earthquake distribution in the NMSZ.

  16. Surface amplitude data: 3D-seismic for interpretation of sea floor geology (Louisiana Slope)

    SciTech Connect

    Roberts, H.H.

    1996-09-01

    Proliferation of 3D-seismic in support of hydrocarbon exploration/production has created new data for improved interpretation of sea floor and shallow subsurface geology. Processing of digital seismic data to enhance amplitude anomalies produces information for improved assessment of geohazards and identification of sensitive benthic communities protected by environmental regulations. Coupled with high resolution acoustic data and direct observation/sampling using a manned research submersible, surface amplitude maps add critical interpretive information for identification of sea floor features. Non-reflective zones (acoustic wipeouts) are associated with many slope features. Mud diapirs, mud mounds, mud volcanoes, gas-changed sediments, gas hydrates, slump deposits, carbonate hardgrounds, and various types of carbonate mounds are all features that exhibit this common response on high resolution seismic profiles. Amplitude data help make specific identifications. Since 1988, submersible data from mid-to-upper slope features (Garden Banks, Green Canyon, and Mississippi Canyon lease block areas) have been analyzed with conventional high resolution acoustic data and 313-amplitude extraction maps. Areas of rapid venting of sediment and hydrocarbon-charged formation fluids are clearly distinguishable from mud diapirs and areas of carbonate mounds (slow seepage). Gas hydrates occur as mounds and mounded zones along faults; products of moderate flux rates below (approx.) 500 in water depths. Gas hydrates function as stored trophic resources that support sensitive chemosynthetic communities. Amplitude extraction maps clearly identify these features by a strong low impedance amplitude anomaly. Refinement and {open_quotes}field calibration{close_quotes} of the surface amplitude extraction method may eventually lead to a new standard for evaluating geohazards and sensitive benthic communities.

  17. Effect of a low-velocity sedimentary cover on the 3-D velocity models derived from inversion of local arrival times. An example from the New Madrid seismic zone.

    NASA Astrophysics Data System (ADS)

    Pujol, J. M.; Chiu, J. M.

    2014-12-01

    When applying seismic tomography to local arrival times from an area with a low-velocity sedimentary cover, the effect of the sediments on travel times should be taken into account. If that is not done, the resulting velocity model(s) cannot be assumed to be correct. This fairly obvious statement has been challenged recently by Powell et al. (JGR, 2010), who claimed that the sediments that cover the New Madrid seismic zone (NMSZ, central United States) can be ignored. This claim is examined here and shown to be incorrect. The NMSZ is covered by low-velocity, poorly consolidated sediments (Vp=1.8 km/s, Vs=3), which are underlain by Paleozoic rocks of much higher velocity. In the central NMSZ the sediment thickness varies between about 0.1 and 0.7 km. The JHD analysis of the data collected in that area by a portable network (PANDA) showed that the P- and S-wave station corrections spanned large ranges (0.35 and 0.63 s, respectively, Pujol et al., Eng. Geol., 1997). This study also showed that a Vp/Vs of 3 for the sediments would be too high if the lateral velocity variations were confined to the sedimentary cover. Here we generate synthetic traveltimes for a model with a sedimentary cover having variable depth (as determined from boreholes) underlain by the high-velocity layers in the 1-D model used for the JHD analysis. The synthetic data were generated for the station and event distributions corresponding to the Panda data. The tomographic inversion of the synthetic times produces spurious anomalies in Vp, Vs, and Vp/Vs, from the surface to a depth of 10 km. In addition, the events are mislocated in depth, with errors between 0 and 1 km for most of them. These results should dispel the notion that the effect of the unconsolidated sediments can be ignored. On the other hand, the inversion of the actual Panda data results in velocity anomalies similar to the synthetic anomalies, although larger, which is consistent with the conclusions of Pujol et al. (1997

  18. Reducing Disk Storage of Full-3D Seismic Waveform Tomography (F3DT) Through Lossy Online Compression

    DOE PAGES

    Lindstrom, Peter; Chen, Po; Lee, En-Jui

    2016-05-05

    Full-3D seismic waveform tomography (F3DT) is the latest seismic tomography technique that can assimilate broadband, multi-component seismic waveform observations into high-resolution 3D subsurface seismic structure models. The main drawback in the current F3DT implementation, in particular the scattering-integral implementation (F3DT-SI), is the high disk storage cost and the associated I/O overhead of archiving the 4D space-time wavefields of the receiver- or source-side strain tensors. The strain tensor fields are needed for computing the data sensitivity kernels, which are used for constructing the Jacobian matrix in the Gauss-Newton optimization algorithm. In this study, we have successfully integrated a lossy compression algorithmmore » into our F3DT SI workflow to significantly reduce the disk space for storing the strain tensor fields. The compressor supports a user-specified tolerance for bounding the error, and can be integrated into our finite-difference wave-propagation simulation code used for computing the strain fields. The decompressor can be integrated into the kernel calculation code that reads the strain fields from the disk and compute the data sensitivity kernels. During the wave-propagation simulations, we compress the strain fields before writing them to the disk. To compute the data sensitivity kernels, we read the compressed strain fields from the disk and decompress them before using them in kernel calculations. Experiments using a realistic dataset in our California statewide F3DT project have shown that we can reduce the strain-field disk storage by at least an order of magnitude with acceptable loss, and also improve the overall I/O performance of the entire F3DT-SI workflow significantly. The integration of the lossy online compressor may potentially open up the possibilities of the wide adoption of F3DT-SI in routine seismic tomography practices in the near future.« less

  19. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N.P. Paulsson

    2005-08-21

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  20. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N. P. Paulsson

    2005-09-30

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  1. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N.P Paulsson

    2006-05-05

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently hampered by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver arrays will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of

  2. DEVELOPMENT OF A 400 LEVEL 3C CLAMPED DOWNHOLE SEISMIC RECEIVER ARRAY FOR 3D BOREHOLE SEISMIC IMAGING OF GAS RESERVOIRS

    SciTech Connect

    Bjorn N.P. Paulsson

    2004-05-01

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to economically do high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology is currently frustrated by the lack of the acquisition technology necessary to record the large volumes of the high frequency, high signal-to-noise-ratio borehole seismic data needed to do 3D imaging. This project takes direct aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array will remove the technical acquisition barrier for recording the necessary volumes of data to do high resolution 3D VSP or 3D cross well seismic imaging. 3D VSP and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that will allow the Gas industry to take the next step in their quest for higher resolution images of the gas reservoirs for the purpose of improving the recovery of the natural gas resources. Today only a fraction of the original Oil or Gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of the detailed compartmentalization of the oil and gas reservoirs. The 400 level 3C borehole seismic receiver array will allow for the economic use of 3D borehole seismic imaging for reservoir characterization and monitoring by allowing the economic recording of the required large data volumes that have a sufficiently dense spatial sampling. By using 3C surface seismic or 3C borehole seismic sources the 400 level receiver array will furthermore allow 3D reservoir imaging using 9C data. The 9C borehole seismic data will provide P, SH and SV information for imaging of the complex deep gas reservoirs and allow quantitative prediction of the rock and the

  3. Interpretation of a 3D Seismic-Reflection Volume in the Basin and Range, Hawthorne, Nevada

    NASA Astrophysics Data System (ADS)

    Louie, J. N.; Kell, A. M.; Pullammanappallil, S.; Oldow, J. S.; Sabin, A.; Lazaro, M.

    2009-12-01

    A collaborative effort by the Great Basin Center for Geothermal Energy at the University of Nevada, Reno, and Optim Inc. of Reno has interpreted a 3d seismic data set recorded by the U.S. Navy Geothermal Programs Office (GPO) at the Hawthorne Army Depot, Nevada. The 3d survey incorporated about 20 NNW-striking lines covering an area of approximately 3 by 10 km. The survey covered an alluvial area below the eastern flank of the Wassuk Range. In the reflection volume the most prominent events are interpreted to be the base of Quaternary alluvium, the Quaternary Wassuk Range-front normal fault zone, and sequences of intercalated Tertiary volcanic flows and sediments. Such a data set is rare in the Basin and Range. Our interpretation reveals structural and stratigraphic details that form a basis for rapid development of the geothermal-energy resources underlying the Depot. We interpret a map of the time-elevation of the Wassuk Range fault and its associated splays and basin-ward step faults. The range-front fault is the deepest, and its isochron map provides essentially a map of "economic basement" under the prospect area. There are three faults that are the most readily picked through vertical sections. The fault reflections show an uncertainty in the time-depth that we can interpret for them of 50 to 200 ms, due to the over-migrated appearance of the processing contractor’s prestack time-migrated data set. Proper assessment of velocities for mitigating the migration artifacts through prestack depth migration is not possible from this data set alone, as the offsets are not long enough for sufficiently deep velocity tomography. The three faults we interpreted appear as gradients in potential-field maps. In addition, the southern boundary of a major Tertiary graben may be seen within the volume as the northward termination of the strong reflections from older Tertiary volcanics. Using a transparent volume view across the survey gives a view of the volcanics in full

  4. High Resolution 3d Modeling of the Behaim Globe

    NASA Astrophysics Data System (ADS)

    Menna, F.; Rizzi, A.; Nocerino, E.; Remondino, F.; Gruen, A.

    2012-07-01

    The article describes the 3D surveying and modeling of the Behaim globe, the oldest still existing and intact globe of the earth, preserved at the German National Museum of Nuremberg, Germany. The work is primarily performed using high-resolution digital images and automatic photogrammetric techniques. Triangulation-based laser scanning is also employed to fill some gaps in the derived image-based 3D geometry and perform geometric comparisons. Major problems are encountered in texture mapping. The 3D modeling project and the creation of high-resolution map-projections is performed for scientific, conservation, visualization and education purposes.

  5. 3D-model building of the jaw impression

    NASA Astrophysics Data System (ADS)

    Ahmed, Moumen T.; Yamany, Sameh M.; Hemayed, Elsayed E.; Farag, Aly A.

    1997-03-01

    A novel approach is proposed to obtain a record of the patient's occlusion using computer vision. Data acquisition is obtained using intra-oral video cameras. The technique utilizes shape from shading to extract 3D information from 2D views of the jaw, and a novel technique for 3D data registration using genetic algorithms. The resulting 3D model can be used for diagnosis, treatment planning, and implant purposes. The overall purpose of this research is to develop a model-based vision system for orthodontics to replace traditional approaches. This system will be flexible, accurate, and will reduce the cost of orthodontic treatments.

  6. Rock formation characterization for CO2-EOR and carbon geosequestration; 3D seismic amplitude and coherency anomalies, Wellington Field, Kansas, USA

    USGS Publications Warehouse

    Ohl, D.; Raef, A.; Watnef, L.; Bhattacharya, S.

    2011-01-01

    In this paper, we present a workflow for a Mississipian carbonates characterization case-study integrating post-stack seismic attributes, well-logs porosities, and seismic modeling to explore relating changes in small-scale "lithofacies" properties and/or sub-seismic resolution faulting to key amplitude and coherency 3D seismic attributes. The main objective of this study is to put emphasis on reservoir characterization that is both optimized for and subsequently benefiting from pilot tertiary CO2-EOR in preparation for future carbon geosequestration in a depleting reservoir and a deep saline aquifer. The extracted 3D seismic coherency attribute indicated anomalous features that can be interpreted as a lithofacies change or a sub-seismic resolution faulting. A 2D finite difference modeling has been undertaken to understand and potentially build discriminant attributes to map structural and/or lithofacies anomalies of interest especially when embarking upon CO2-EOR and/or carbon sequestration monitoring and management projects. ?? 2011 Society of Exploration Geophysicists.

  7. Summary on several key techniques in 3D geological modeling.

    PubMed

    Mei, Gang

    2014-01-01

    Several key techniques in 3D geological modeling including planar mesh generation, spatial interpolation, and surface intersection are summarized in this paper. Note that these techniques are generic and widely used in various applications but play a key role in 3D geological modeling. There are two essential procedures in 3D geological modeling: the first is the simulation of geological interfaces using geometric surfaces and the second is the building of geological objects by means of various geometric computations such as the intersection of surfaces. Discrete geometric surfaces that represent geological interfaces can be generated by creating planar meshes first and then spatially interpolating; those surfaces intersect and then form volumes that represent three-dimensional geological objects such as rock bodies. In this paper, the most commonly used algorithms of the key techniques in 3D geological modeling are summarized.

  8. Summary on Several Key Techniques in 3D Geological Modeling

    PubMed Central

    2014-01-01

    Several key techniques in 3D geological modeling including planar mesh generation, spatial interpolation, and surface intersection are summarized in this paper. Note that these techniques are generic and widely used in various applications but play a key role in 3D geological modeling. There are two essential procedures in 3D geological modeling: the first is the simulation of geological interfaces using geometric surfaces and the second is the building of geological objects by means of various geometric computations such as the intersection of surfaces. Discrete geometric surfaces that represent geological interfaces can be generated by creating planar meshes first and then spatially interpolating; those surfaces intersect and then form volumes that represent three-dimensional geological objects such as rock bodies. In this paper, the most commonly used algorithms of the key techniques in 3D geological modeling are summarized. PMID:24772029

  9. Formal representation of 3D structural geological models

    NASA Astrophysics Data System (ADS)

    Wang, Zhangang; Qu, Honggang; Wu, Zixing; Yang, Hongjun; Du, Qunle

    2016-05-01

    The development and widespread application of geological modeling methods has increased demands for the integration and sharing services of three dimensional (3D) geological data. However, theoretical research in the field of geological information sciences is limited despite the widespread use of Geographic Information Systems (GIS) in geology. In particular, fundamental research on the formal representations and standardized spatial descriptions of 3D structural models is required. This is necessary for accurate understanding and further applications of geological data in 3D space. In this paper, we propose a formal representation method for 3D structural models using the theory of point set topology, which produces a mathematical definition for the major types of geological objects. The spatial relationships between geologic boundaries, structures, and units are explained in detail using the 9-intersection model. Reasonable conditions for describing the topological space of 3D structural models are also provided. The results from this study can be used as potential support for the standardized representation and spatial quality evaluation of 3D structural models, as well as for specific needs related to model-based management, query, and analysis.

  10. Vehicle Surveillance with a Generic, Adaptive, 3D Vehicle Model.

    PubMed

    Leotta, Matthew J; Mundy, Joseph L

    2011-07-01

    In automated surveillance, one is often interested in tracking road vehicles, measuring their shape in 3D world space, and determining vehicle classification. To address these tasks simultaneously, an effective approach is the constrained alignment of a prior model of 3D vehicle shape to images. Previous 3D vehicle models are either generic but overly simple or rigid and overly complex. Rigid models represent exactly one vehicle design, so a large collection is needed. A single generic model can deform to a wide variety of shapes, but those shapes have been far too primitive. This paper uses a generic 3D vehicle model that deforms to match a wide variety of passenger vehicles. It is adjustable in complexity between the two extremes. The model is aligned to images by predicting and matching image intensity edges. Novel algorithms are presented for fitting models to multiple still images and simultaneous tracking while estimating shape in video. Experiments compare the proposed model to simple generic models in accuracy and reliability of 3D shape recovery from images and tracking in video. Standard techniques for classification are also used to compare the models. The proposed model outperforms the existing simple models at each task.

  11. Double-difference relocations and spectral ratio analysis of volcanic seismic events in the Mount St. Helens crater using a 3D velocity model suggest slip events under the new dome with constant stress-drop scaling.

    NASA Astrophysics Data System (ADS)

    Harrington, R. M.; Kwiatek, G.; Moran, S. C.

    2014-12-01

    Shallow low frequency seismic events are common features associated with restless and erupting volcanoes. The physical mechanisms generating their characteristic low frequency, and often extended duration signals remain poorly understood. Here we present new double-difference relocations and spectral scaling of a group of ~400 shallow low-frequency seismic events occurring within the Mount St. Helens edifice during its 2004-2008 dome-building eruption, as recorded by a temporary seismic array for a month within the crater in 2006. Relocation results suggest that the majority of earthquakes occurred in the center of the crater close to the vent at depths < 500 m, with some events potentially locating under the new dome but ~200-300m southwest of the vent. Low-frequency events exhibit moment-corner frequency scaling roughly consistent with a constant static stress-drop, similar to tectonic earthquakes occurring elsewhere in shallow crustal faults. The scaling suggests that the ~400 events result from stick-slip behavior, and that the low frequency character of the waveforms may result from a combination of path effects and slow rupture speeds. For relocation, we divide the 400 events into eight families based on waveform similarity, and use a subset of nearly 40 earthquakes with clear first arrivals ranging in moment magnitude from 0.4 - 1.8 to calculate hypocenters. We then relocate these events using a double-difference method with a three-dimensional velocity model of the edifice from Waite and Moran (2009). The relocated events are then used to estimate source parameters of the remaining earthquakes via a spectral ratio technique. Spectral corner frequency estimations based on this spectral ratio approach produce stress-drop values of ~1 MPa assuming a shear-wave velocity of 1500 m/s. The estimations also indicate a constant stress-drop scaling for all events, with two event families having lower estimated stress drops of ~0.1 MPa. While localized lithological

  12. 3D Modeling from Photos Given Topological Information.

    PubMed

    Kim, Young Min; Cho, Junghyun; Ahn, Sang Chul

    2016-09-01

    Reconstructing 3D models given a single-view 2D information is inherently an ill-posed problem and requires additional information such as shape prior or user input.We introduce a method to generate multiple 3D models of a particular category given corresponding photographs when the topological information is known. While there is a wide range of shapes for an object of a particular category, the basic topology usually remains constant.In consequence, the topological prior needs to be provided only once for each category and can be easily acquired by consulting an existing database of 3D models or by user input. The input of topological description is only connectivity information between parts; this is in contrast to previous approaches that have required users to interactively mark individual parts. Given the silhouette of an object and the topology, our system automatically finds a skeleton and generates a textured 3D model by jointly fitting multiple parts. The proposed method, therefore, opens the possibility of generating a large number of 3D models by consulting a massive number of photographs. We demonstrate examples of the topological prior and reconstructed 3D models using photos.

  13. Performance Evaluation of 3d Modeling Software for Uav Photogrammetry

    NASA Astrophysics Data System (ADS)

    Yanagi, H.; Chikatsu, H.

    2016-06-01

    UAV (Unmanned Aerial Vehicle) photogrammetry, which combines UAV and freely available internet-based 3D modeling software, is widely used as a low-cost and user-friendly photogrammetry technique in the fields such as remote sensing and geosciences. In UAV photogrammetry, only the platform used in conventional aerial photogrammetry is changed. Consequently, 3D modeling software contributes significantly to its expansion. However, the algorithms of the 3D modelling software are black box algorithms. As a result, only a few studies have been able to evaluate their accuracy using 3D coordinate check points. With this motive, Smart3DCapture and Pix4Dmapper were downloaded from the Internet and commercial software PhotoScan was also employed; investigations were performed in this paper using check points and images obtained from UAV.

  14. Constraining 3D Process Sedimentological Models to Geophysical Data Using Image Quilting

    NASA Astrophysics Data System (ADS)

    Tahmasebi, P.; Da Pra, A.; Pontiggia, M.; Caers, J.

    2014-12-01

    3D process geological models, whether for carbonate or sedimentological systems, have been proposed for modeling realistic subsurface heterogeneity. The problem with such forward process models is that they are not constrained to any subsurface data whether to wells or geophysical surveys. We propose a new method for realistic geological modeling of complex heterogeneity by hybridizing 3D process modeling of geological deposition with conditioning by means of a novel multiple-point geostatistics (MPS) technique termed image quilting (IQ). Image quilting is a pattern-based techniques that stiches together patterns extracted from training images to generate stochastic realizations that look like the training image. In this paper, we illustrate how 3D process model realizations can be used as training images in image quilting. To constrain the realization to seismic data we first interpret each facies in the geophysical data. These interpretation, while overly smooth and not reflecting finer scale variation are used as auxiliary variables in the generation of the image quilting realizations. To condition to well data, we first perform a kriging of the well data to generate a kriging map and kriging variance. The kriging map is used as additional auxiliary variable while the kriging variance is used as a weight given to the kriging derived auxiliary variable. We present an application to a giant offshore reservoir. Starting from seismic advanced attribute analysis and sedimentological interpretation, we build the 3D sedimentological process based model and use it as non-stationary training image for conditional image quilting.

  15. INCREASING OIL RECOVERY THROUGH ADVANCED REPROCESSING OF 3D SEISMIC, GRANT CANYON AND BACON FLAT FIELDS, NYE COUNTY, NEVADA

    SciTech Connect

    Eric H. Johnson; Don E. French

    2001-06-01

    Makoil, Inc., of Orange, California, with the support of the U.S. Department of Energy has reprocessed and reinterpreted the 3D seismic survey of the Grant Canyon area, Railroad Valley, Nye County, Nevada. The project was supported by Dept. of Energy Grant DE-FG26-00BC15257. The Grant Canyon survey covers an area of 11 square miles, and includes Grant Canyon and Bacon Flat oil fields. These fields have produced over 20 million barrels of oil since 1981, from debris slides of Devonian rocks that are beneath 3,500 to 5,000 ft of Tertiary syntectonic deposits that fill the basin of Railroad Valley. High-angle and low-angle normal faults complicate the trap geometry of the fields, and there is great variability in the acoustic characteristics of the overlying valley fill. These factors combine to create an area that is challenging to interpret from seismic reflection data. A 3D seismic survey acquired in 1992-93 by the operator of the fields has been used to identify development and wildcat locations with mixed success. Makoil believed that improved techniques of processing seismic data and additional well control could enhance the interpretation enough to improve the chances of success in the survey area. The project involved the acquisition of hardware and software for survey interpretation, survey reprocessing, and reinterpretation of the survey. SeisX, published by Paradigm Geophysical Ltd., was chosen as the interpretation software, and it was installed on a Dell Precision 610 computer work station with the Windows NT operating system. The hardware and software were selected based on cost, possible addition of compatible modeling software in the future, and the experience of consulting geophysicists in the Billings area. Installation of the software and integration of the hardware into the local office network was difficult at times but was accomplished with some technical support from Paradigm and Hewlett Packard, manufacturer of some of the network equipment. A

  16. Automatic Texture Mapping of Architectural and Archaeological 3d Models

    NASA Astrophysics Data System (ADS)

    Kersten, T. P.; Stallmann, D.

    2012-07-01

    Today, detailed, complete and exact 3D models with photo-realistic textures are increasingly demanded for numerous applications in architecture and archaeology. Manual texture mapping of 3D models by digital photographs with software packages, such as Maxon Cinema 4D, Autodesk 3Ds Max or Maya, still requires a complex and time-consuming workflow. So, procedures for automatic texture mapping of 3D models are in demand. In this paper two automatic procedures are presented. The first procedure generates 3D surface models with textures by web services, while the second procedure textures already existing 3D models with the software tmapper. The program tmapper is based on the Multi Layer 3D image (ML3DImage) algorithm and developed in the programming language C++. The studies showing that the visibility analysis using the ML3DImage algorithm is not sufficient to obtain acceptable results of automatic texture mapping. To overcome the visibility problem the Point Cloud Painter algorithm in combination with the Z-buffer-procedure will be applied in the future.

  17. Quasi-3D Algorithm in Multi-scale Modeling Framework

    NASA Astrophysics Data System (ADS)

    Jung, J.; Arakawa, A.

    2008-12-01

    As discussed in the companion paper by Arakawa and Jung, the Quasi-3D (Q3D) Multi-scale Modeling Framework (MMF) is a 4D estimation/prediction framework that combines a GCM with a 3D anelastic vector vorticity equation model (VVM) applied to a Q3D network of horizontal grid points. This paper presents an outline of the recently revised Q3D algorithm and a highlight of the results obtained by application of the algorithm to an idealized model setting. The Q3D network of grid points consists of two sets of grid-point arrays perpendicular to each other. For a scalar variable, for example, each set consists of three parallel rows of grid points. Principal and supplementary predictions are made on the central and the two adjacent rows, respectively. The supplementary prediction is to allow the principal prediction be three-dimensional at least to the second-order accuracy. To accommodate a higher-order accuracy and to make the supplementary predictions formally three-dimensional, a few rows of ghost points are added at each side of the array. Values at these ghost points are diagnostically determined by a combination of statistical estimation and extrapolation. The basic structure of the estimation algorithm is determined in view of the global stability of Q3D advection. The algorithm is calibrated using the statistics of past data at and near the intersections of the two sets of grid- point arrays. Since the CRM in the Q3D MMF extends beyond individual GCM boxes, the CRM can be a GCM by itself. However, it is better to couple the CRM with the GCM because (1) the CRM is a Q3D CRM based on a highly anisotropic network of grid points and (2) coupling with a GCM makes it more straightforward to inherit our experience with the conventional GCMs. In the coupled system we have selected, prediction of thermdynamic variables is almost entirely done by the Q3D CRM with no direct forcing by the GCM. The coupling of the dynamics between the two components is through mutual

  18. 3D numerical modeling of India-Asia-like collision

    NASA Astrophysics Data System (ADS)

    -Erika Püsök, Adina; Kaus, Boris; Popov, Anton

    2013-04-01

    above a strong mantle lithosphere - the jelly sandwich model (Burov and Watts, 2006). 3D models are thus needed to investigate these hypotheses. However, fully 3D models of the dynamics of continent collision zones have only been developed very recently, and presently most research groups have relied on certain explicit assumptions for their codes. Here, we employ the parallel 3D code LaMEM (Lithosphere and Mantle Evolution Model), with a finite difference staggered grid solver, which is capable of simulating lithospheric deformation while simultaneously taking mantle flow and a free surface into account. We here report on first lithospheric and upper-mantle scale simulations in which the Indian lithosphere is indented into Asia. Acknowledgements. Funding was provided by the European Research Council under the European Community's Seventh Framework Program (FP7/2007-2013) / ERC Grant agreement #258830. Numerical computations have been performed on JUQUEEN of the Jülich high-performance computing center. • Beaumont, C., Jamieson, R.A., Nguyen, M.H., Medvedev, S.E., 2004. Crustal channel flows: 1. Numerical models with applications to the tectonics of the Himalayan-Tibetan orogeny. J. Geophys. Res. 109, B06406. • Burov, E. & Watts, W.S., 2006. The long-term strength of continental lithosphere: "jelly sandwich" or "crème brûlée"?. GSA Today, 16, doi: 10.1130/1052-5173(2006)1016<1134:TLTSOC>1132.1130.CO;1132. • England P., Houseman, G., 1986. Finite strain calculations of continental deformation. 2. Comparison with the India-Asia collision zone. J. Geophys. Res.- Solid Earth and Planets 91 (B3), 3664-3676. • Jackson, J., 2002. Strength of the continental lithosphere: time to abandon the jelly sandwich?. GSA Today, September, 4-10. • Lechmann, S.M., May, D.A., Kaus, B.J.P., Schmalholz, S.M., 2011. Comparing thin-sheet models with 3D multilayer models for continental collision. Geophy. Int. J. doi: 10.1111/j.1365-246X.2011.05164.x • Royden, L.H., Burchfiel, B

  19. High Rayleigh Number 3d Spherical Mantle Convection Models

    NASA Astrophysics Data System (ADS)

    Davies, J. H.

    2003-04-01

    The geochemical and geophysical evidence related to the mantle can potentially be reconciled by a hypothesis of whole mantle convection where the heterogeneity stems from the continuous recycling of oceanic crust, depleted lithospheric mantle and sediments. The mantle is expected to be well but not perfectly stirred, sampled differently in different tectonic settings, and with components having wide-ranging residence times. We might for example expect very long residence times for some buoyant or dense components that can reside in either the upper (lithosphere) or lower boundary (D''). We have started testing whether such a whole mantle convection hypothesis can satisfy wide ranging first order geophysical observations, such as plate velocities, stability of upwellings, geometry of downwellings, etc. The model parameters, including the mantle's viscosity structure, are guided by extensive earlier community work. We use TERRA to model compressible convection in a 3D spherical mantle shell with a depth dependent viscosity structure, where the lower mantle is 40 times more viscous than the upper mantle. A chondritic rate of internal heating of 6 x 10^-12 W/Kg was assumed, leading to Ra(H) = 3.4x10^8. A realistic depth dependent thermal expansivity and Murnaghan equation of state was assumed, with free slip b.c.. The evolution of the system was followed for 2 Billion years. The RMS surface velocity varied from around 4 - 7cm/yr, very similar to recent plate velocities. The structures in the lower mantle are relatively stable and larger length scale in comparison to the upper mantle features. The downwellings and upwellings are linear in planform but the upwellings are dominated by stronger upflow at the columns formed at their intersection. The upwelling features embedded in the lower mantle are very stable, and it is reasonable to expect (though yet to be demonstrated) that with temperature-dependent viscosity the upwellings will be dominated by the cylindrical

  20. Gis-Based Smart Cartography Using 3d Modeling

    NASA Astrophysics Data System (ADS)

    Malinverni, E. S.; Tassetti, A. N.

    2013-08-01

    3D City Models have evolved to be important tools for urban decision processes and information systems, especially in planning, simulation, analysis, documentation and heritage management. On the other hand existing and in use numerical cartography is often not suitable to be used in GIS because not geometrically and topologically correctly structured. The research aim is to 3D structure and organize a numeric cartography for GIS and turn it into CityGML standardized features. The work is framed around a first phase of methodological analysis aimed to underline which existing standard (like ISO and OGC rules) can be used to improve the quality requirement of a cartographic structure. Subsequently, from this technical specifics, it has been investigated the translation in formal contents, using an owner interchange software (SketchUp), to support some guide lines implementations to generate a GIS3D structured in GML3. It has been therefore predisposed a test three-dimensional numerical cartography (scale 1:500, generated from range data captured by 3D laser scanner), tested on its quality according to the previous standard and edited when and where necessary. Cad files and shapefiles are converted into a final 3D model (Google SketchUp model) and then exported into a 3D city model (CityGML LoD1/LoD2). The GIS3D structure has been managed in a GIS environment to run further spatial analysis and energy performance estimate, not achievable in a 2D environment. In particular geometrical building parameters (footprint, volume etc.) are computed and building envelop thermal characteristics are derived from. Lastly, a simulation is carried out to deal with asbestos and home renovating charges and show how the built 3D city model can support municipal managers with risk diagnosis of the present situation and development of strategies for a sustainable redevelop.

  1. 3D-seismic observations of Late Pleistocene glacial dynamics on the central West Greenland margin

    NASA Astrophysics Data System (ADS)

    Hofmann, Julia; Knutz, Paul; Cofaigh, Colm Ó.

    2016-04-01

    Fast-flowing ice streams and outlet glaciers exert a major control on glacial discharge from contemporary and palaeo ice sheets. Improving our understanding of the extent and dynamic behaviour of these palaeo-ice streams is therefore crucial for predictions of the response of ice sheets to present and future climate warming and the associated implications for global sea level. This poster presents results from two 3D-seismic surveys located on the shelf adjoining the Disko Bay trough-mouth fan (TMF), one of the largest glacial outlet systems in Greenland. Located at the seaward terminus of the c. 370 km long cross-shelf Disko Trough, the Disko Bay TMF was generated by highly efficient subglacial sediment delivery onto the continental slopes during repeated ice-stream advances. A variety of submarine glacial landform assemblages are recognised on the seabed reflecting past ice-stream activity presumably related to glacial-interglacial cycles. The 3D-seismic volumes cover the shallow banks located north and south of the Disko Trough. The focus of this study is the seabed and the uppermost stratigraphic interval associated with the Late Stage of TMF development, presumably covering the late Pleistocene (Hofmann et al., submitted). Seabed morphologies include multiple sets of ridges up to 20 m high that extend in NW-SE direction for c. 30 km, and cross-cutting curvilinear furrows with maximum lengths of c. 9 km and average depths of c. 4.5 m. Back-stepping, arcuate scarps facing NW define the shelf break on the northern survey, comprising average widths of c. 4.5 km and incision depths of c. 27.5 m. The large transverse ridge features on the southern survey are likely ice-marginal and are interpreted as terminal moraine ridges recording the existence of a shelf-edge terminating, grounded Late Weichselian ice sheet. The furrows, most prominent on the outer shelf adjoining the shallow banks and partly incising the moraine ridges, are interpreted as iceberg ploughmarks

  2. Combined registration of 3D tibia and femur implant models in 3D magnetic resonance images

    NASA Astrophysics Data System (ADS)

    Englmeier, Karl-Hans; Siebert, Markus; von Eisenhart-Rothe, Ruediger; Graichen, Heiko

    2008-03-01

    The most frequent reasons for revision of total knee arthroplasty are loosening and abnormal axial alignment leading to an unphysiological kinematic of the knee implant. To get an idea about the postoperative kinematic of the implant, it is essential to determine the position and orientation of the tibial and femoral prosthesis. Therefore we developed a registration method for fitting 3D CAD-models of knee joint prostheses into an 3D MR image. This rigid registration is the basis for a quantitative analysis of the kinematics of knee implants. Firstly the surface data of the prostheses models are converted into a voxel representation; a recursive algorithm determines all boundary voxels of the original triangular surface data. Secondly an initial preconfiguration of the implants by the user is still necessary for the following step: The user has to perform a rough preconfiguration of both remaining prostheses models, so that the fine matching process gets a reasonable starting point. After that an automated gradient-based fine matching process determines the best absolute position and orientation: This iterative process changes all 6 parameters (3 rotational- and 3 translational parameters) of a model by a minimal amount until a maximum value of the matching function is reached. To examine the spread of the final solutions of the registration, the interobserver variability was measured in a group of testers. This variability, calculated by the relative standard deviation, improved from about 50% (pure manual registration) to 0.5% (rough manual preconfiguration and subsequent fine registration with the automatic fine matching process).

  3. Implementation of virtual models from sheet metal forming simulation into physical 3D colour models using 3D printing

    NASA Astrophysics Data System (ADS)

    Junk, S.

    2016-08-01

    Today the methods of numerical simulation of sheet metal forming offer a great diversity of possibilities for optimization in product development and in process design. However, the results from simulation are only available as virtual models. Because there are any forming tools available during the early stages of product development, physical models that could serve to represent the virtual results are therefore lacking. Physical 3D-models can be created using 3D-printing and serve as an illustration and present a better understanding of the simulation results. In this way, the results from the simulation can be made more “comprehensible” within a development team. This paper presents the possibilities of 3D-colour printing with particular consideration of the requirements regarding the implementation of sheet metal forming simulation. Using concrete examples of sheet metal forming, the manufacturing of 3D colour models will be expounded upon on the basis of simulation results.

  4. Evolution of Submarine Gullies on a Prograding Slope: Insights from 3D Seismic Reflection Data

    NASA Astrophysics Data System (ADS)

    Shumaker, L.; Jobe, Z. R.

    2014-12-01

    Submarine gullies are common features on continental slopes on both passive and active margins, but the processes dictating gully formation and the role of gullies in deep-water sediment transport are topics of debate. The geometries of gullies can provide clues to understanding the processes by which they initiate and grow, particularly when considered in the context of surrounding submarine geomorphology. Further confidence in these interpretations can be gained by tracking the temporal history of gullies with evolution of the continental margin. The 500 km2 Tui 3D seismic survey from the Taranaki Basin, New Zealand, shows continental slope gullies and other channel features in a ~1 km-thick package of prograding shelf-slope clinoforms that developed over Pliocene-Pleistocene time. This dataset allows for documentation of gullies over ~3 Ma, through numerous cycles of initiation and burial. For this study, we manually interpreted clinoform packages to generate 'paleo-seafloor' surfaces that provide context such as position of the shelf edge, slope gradient and azimuth, and relative progradation and aggradation magnitudes. Gully geometries were obtained from detailed seismic interpretation guided by semblance and RMS amplitude imaging on these surfaces. Gullies are low sinuosity, with widths ranging from ~50-150 m and depths from a few tens to <100 m. Gullies are observed to grow in width and relief downslope without evidence for aggradational confinement (levees), and in some cases form gully 'complexes' hundreds of m wide in the lower slope region. These complexes are present through >150 m of stratigraphy, indicating that they are long-lived features on the slope. This further indicates that the frequency of flows along the gullies was enough to maintain their topographic expression during slope progradation and aggradation, and suggests that gullies play an integral role in transport processes on the slope.

  5. High-resolution 3-D S-wave Tomography of upper crust structures in Yilan Plain from Ambient Seismic Noise

    NASA Astrophysics Data System (ADS)

    Chen, Kai-Xun; Chen, Po-Fei; Liang, Wen-Tzong; Chen, Li-Wei; Gung, YuanCheng

    2015-04-01

    The Yilan Plain (YP) in NE Taiwan locates on the western YP of the Okinawa Trough and displays high geothermal gradients with abundant hot springs, likely resulting from magmatism associated with the back-arc spreading as attested by the offshore volcanic island (Kueishantao). YP features NS distinctive characteristics that the South YP exhibits thin top sedimentary layer, high on-land seismicity and significant SE movements, relative those of the northern counterpart. A dense network (~2.5 km station interval) of 89 Texan instruments was deployed in Aug. 2014, covering most of the YP and its vicinity. The ray path coverage density of each 0.015 degree cells are greater than 150 km that could provide the robustness assessment of tomographic results. We analyze ambient noise signals to invert a high-resolution 3D S-wave model for shallow velocity structures in and around YP. The aim is to investigate the velocity anomalies corresponding to geothermal resources and the NS geological distinctions aforementioned. We apply the Welch's method to generate empirical Rayleigh wave Green's functions between two stations records of continuous vertical components. The group velocities of thus derived functions are then obtained by the multiple-filter analysis technique measured at the frequency range between 0.25 and 1 Hz. Finally, we implement a wavelet-based multi-scale parameterization technique to construct 3D model of S-wave velocity. Our first month results exhibit low velocity in the plain, corresponding existing sediments, those of whole YP show low velocity offshore YP and those of high-resolution south YP reveal stark velocity contrast across the Sanshin fault. Key words: ambient seismic noises, Welch's method, S-wave, Yilan Plain

  6. 3D Bioprinting of Tissue/Organ Models.

    PubMed

    Pati, Falguni; Gantelius, Jesper; Svahn, Helene Andersson

    2016-04-04

    In vitro tissue/organ models are useful platforms that can facilitate systematic, repetitive, and quantitative investigations of drugs/chemicals. The primary objective when developing tissue/organ models is to reproduce physiologically relevant functions that typically require complex culture systems. Bioprinting offers exciting prospects for constructing 3D tissue/organ models, as it enables the reproducible, automated production of complex living tissues. Bioprinted tissues/organs may prove useful for screening novel compounds or predicting toxicity, as the spatial and chemical complexity inherent to native tissues/organs can be recreated. In this Review, we highlight the importance of developing 3D in vitro tissue/organ models by 3D bioprinting techniques, characterization of these models for evaluating their resemblance to native tissue, and their application in the prioritization of lead candidates, toxicity testing, and as disease/tumor models.

  7. 3D WHOLE-PROMINENCE FINE STRUCTURE MODELING

    SciTech Connect

    Gunár, Stanislav; Mackay, Duncan H.

    2015-04-20

    We present the first 3D whole-prominence fine structure model. The model combines a 3D magnetic field configuration of an entire prominence obtained from nonlinear force-free field simulations, with a detailed description of the prominence plasma. The plasma is located in magnetic dips in hydrostatic equilibrium and is distributed along multiple fine structures within the 3D magnetic model. Through the use of a novel radiative transfer visualization technique for the Hα line such plasma-loaded magnetic field model produces synthetic images of the modeled prominence comparable with high-resolution observations. This allows us for the first time to use a single technique to consistently study, in both emission on the limb and absorption against the solar disk, the fine structures of prominences/filaments produced by a magnetic field model.

  8. 3D web visualization of huge CityGML models

    NASA Astrophysics Data System (ADS)

    Prandi, F.; Devigili, F.; Soave, M.; Di Staso, U.; De Amicis, R.

    2015-08-01

    Nowadays, rapid technological development into acquiring geo-spatial information; joined to the capabilities to process these data in a relative short period of time, allows the generation of detailed 3D textured city models that will become an essential part of the modern city information infrastructure (Spatial Data Infrastructure) and, can be used to integrate various data from different sources for public accessible visualisation and many other applications. One of the main bottlenecks, which at the moment limit the use of these datasets to few experts, is a lack on efficient visualization systems through the web and interoperable frameworks that allow standardising the access to the city models. The work presented in this paper tries to satisfy these two requirements developing a 3D web-based visualization system based on OGC standards and effective visualization concepts. The architectural framework, based on Services Oriented Architecture (SOA) concepts, provides the 3D city data to a web client designed to support the view process in a very effective way. The first part of the work is to design a framework compliant to the 3D Portrayal Service drafted by the of the Open Geospatial Consortium (OGC) 3D standardization working group. The latter is related to the development of an effective web client able to render in an efficient way the 3D city models.

  9. 3D microstructure modeling of compressed fiber-based materials

    NASA Astrophysics Data System (ADS)

    Gaiselmann, Gerd; Tötzke, Christian; Manke, Ingo; Lehnert, Werner; Schmidt, Volker

    2014-07-01

    A novel parametrized model that describes the 3D microstructure of compressed fiber-based materials is introduced. It allows to virtually generate the microstructure of realistically compressed gas-diffusion layers (GDL). Given the input of a 3D microstructure of some fiber-based material, the model compresses the system of fibers in a uniaxial direction for arbitrary compression rates. The basic idea is to translate the fibers in the direction of compression according to a vector field which depends on the rate of compression and on the locations of fibers within the material. In order to apply the model to experimental 3D image data of fiber-based materials given for several compression states, an optimal vector field is estimated by simulated annealing. The model is applied to 3D image data of non-woven GDL in PEMFC gained by synchrotron tomography for different compression rates. The compression model is validated by comparing structural characteristics computed for experimentally compressed and virtually compressed microstructures, where two kinds of compression - using a flat stamp and a stamp with a flow-field profile - are applied. For both stamps types, a good agreement is found. Furthermore, the compression model is combined with a stochastic 3D microstructure model for uncompressed fiber-based materials. This allows to efficiently generate compressed fiber-based microstructures in arbitrary volumes.

  10. Mount Etna: 3-D and 4-D structure using seismic tomography

    NASA Astrophysics Data System (ADS)

    Nunn, C.; Julian, B. R.; Foulger, G. R.; Patanè, D.; Ibáñez, J. M.; Briole, P.; Mhanna, N.

    2015-12-01

    We investigate the time-varying structure of Etna, an active stratovolcano in eastern Sicily, using seismic tomography. In volcanic systems, it is thought that the presence of fluids, cracks and pressurized gases can rapidly and drastically change the elastic properties of the host rocks. Recent work suggests that changes beneath Etna are detectable with seismic methods, and that these changes can be linked to volcanic activity. Temporal changes to Earth structure are commonly investigated by carrying out separate tomographic inversions for different epochs. However, repeated inversions of the same area are expected to vary, even if the structure itself does not change. This is due to variations in the seismic ray distribution and to observational errors. Potentially, changes between epochs which are due to experimental limitations can be misinterpreted as changes to the structure of the volcano. Consequently, we use a new tomographic program, TOMO4D, that inverts multiple data sets simultaneously [Julian & Foulger, Time-dependent seismic tomography, GJI, 2010]. This code imposes constraints which minimise the differences calculated between two epochs. The remaining structural variations are thus truly required to fit the data, and reflect changes which almost certainly exist between the two epochs. We have selected and relocated ~400 local earthquakes with at least 5 P and 5 S observations. They cover a period which includes several eruptions, from 1st November 2000 to 31st December 2006. We divide our data into different epochs and invert two epochs simultaneously. The models show a seismically fast central region, surrounded by a slower outer region. This suggests a central system of dykes or sills surrounded by volcanic sediments and country rock. At depths of 0-4 km below sea level the seismically fast region is not below the summit crater but is offset to the southwest. By monitoring the changes to the elastic parameters of the host rocks we observe temporal

  11. Simulation of instrumental intensities in the Tokyo Metropolitan area using a 3D attenuation structure model.

    NASA Astrophysics Data System (ADS)

    Panayotopoulos, Y.; Hirata, N.; Sakai, S.; Nakagawa, S.; Kasahara, K.

    2015-12-01

    In recent years the development of dense seismic networks in Japan has enabled high quality observations of instrumental intensities. However, the distribution of intensities of historical earthquakes can only be retrieved by the damage reports on historical documents. Their epicenter and magnitude can be roughly estimated from the intensity distribution, assuming that seismic intensity decays with distance. This approximation is not always accurate, since the amplitude of short period ground motion decays with focal distance and is affected by the 3D attenuation structure along the path and in addition displays frequency dependence. In order to estimate the location and size of a large historical earthquake, we need to accurately simulate the seismic intensity distribution, accounting for non linear attenuation of seismic waves along the path. The instrumental seismic intensities inside the Kanto basin observed at the Tokyo Metropolitan Seismic Observation network (MeSO-net) and Hi-net stations display unusual distribution patterns, with peak intensities observed several km away from the epicenter rather than at the stations closer to it. In order to understand the source of this intensity distribution, we estimated the theoretical instrumental intensities using a 3D attenuation structure and compare it to the observed intensity distribution. We first estimated a 3D attenuation structure using the spectral decay of seismic waves, by fitting the observed seismic wave spectrum to a theoretical spectrum using an ω2 model. The obtained model suggests Qs values of 50˜100 inside the Kanto basin and low Qs values < 300 in the area where the Philippine Sea plate meets the upper part of the Pacific plate. We then use an ω2 model in order to estimate the source acceleration spectrum of several earthquakes occurring below the Kanto basin at depths ranging 30~80 km. Our simulation shows that earthquakes occurring on the Pacific plate pass through the low Qs area inside the

  12. 3-D Tomography Study of Seismic Refraction/Wide-Angle Reflection Data Across the Variscides, SW Ireland

    NASA Astrophysics Data System (ADS)

    O'Reilly, B. M.; Landes, M.; Readman, P. W.; Shannon, P. M.; Prodehl, C.

    2002-12-01

    The VARNET-96 seismic experiment acquired three seismic refraction/wide-angle reflection profiles in order to examine the crustal structure in the south-west of Ireland. 170 seismic stations were used on 300 recording sites. The shotpoint geometry was designed to allow for both in-line and off-line fan shot recordings on the three profiles. A total of 34 water shots was fired. Results from 3-D raytrace and inversion modelling illustrate the pervasive lateral heterogeneity of the study area south of the Shannon Estuary. Palaeozoic strata at the south coast are about 5-6 km thick associated with the sedimentary infill of the Munster and South Munster Basins. To the north, shallow upper crust in the vicinity of the Killarney-Mallow Fault Zone is followed by a 3-4 km thick sedimentary succession in the Dingle-Shannon Basin. A zone of high-velocity upper crust (6.4-6.6 km/s) beneath the South Munster Basin correlates with a gravity high between the Kenmare-Killarney and the Leinster Granite gravity lows. Other high-velocity zones were found beneath Dingle Bay and the Kenmare River region and may be associated with the deep traces of the Killarney-Mallow Fault Zone and the Cork-Kenmare Line. The 3-D velocity model was taken as a basis for the computation of PmP reflected arrivals from the crust-mantle boundary. The Moho depth varies from about 28-29 km at the south coast to about 32-33 km beneath the Dingle-Shannon Basin, the region where the 2-D inline model shows a south-dipping reflector in the upper mantle. Pervasive Variscan deformation appears to be confined to the sedimentary and upper crustal structure and has not deformed the entire crust supporting a thin-skinned tectonic model for Variscan deformation. Deep-crustal variations only occur where they can be correlated with major tectonic features such as the Caledonian Iapetus Suture near the Shannon Estuary. The shallowing of the Moho towards the coast may result from Mesozoic crustal extension in the adjacent

  13. Perception-based shape retrieval for 3D building models

    NASA Astrophysics Data System (ADS)

    Zhang, Man; Zhang, Liqiang; Takis Mathiopoulos, P.; Ding, Yusi; Wang, Hao

    2013-01-01

    With the help of 3D search engines, a large number of 3D building models can be retrieved freely online. A serious disadvantage of most rotation-insensitive shape descriptors is their inability to distinguish between two 3D building models which are different at their main axes, but appear similar when one of them is rotated. To resolve this problem, we present a novel upright-based normalization method which not only correctly rotates such building models, but also greatly simplifies and accelerates the abstraction and the matching of building models' shape descriptors. Moreover, the abundance of architectural styles significantly hinders the effective shape retrieval of building models. Our research has shown that buildings with different designs are not well distinguished by the widely recognized shape descriptors for general 3D models. Motivated by this observation and to further improve the shape retrieval quality, a new building matching method is introduced and analyzed based on concepts found in the field of perception theory and the well-known Light Field descriptor. The resulting normalized building models are first classified using the qualitative shape descriptors of Shell and Unevenness which outline integral geometrical and topological information. These models are then put in on orderly fashion with the help of an improved quantitative shape descriptor which we will term as Horizontal Light Field Descriptor, since it assembles detailed shape characteristics. To accurately evaluate the proposed methodology, an enlarged building shape database which extends previous well-known shape benchmarks was implemented as well as a model retrieval system supporting inputs from 2D sketches and 3D models. Various experimental performance evaluation results have shown that, as compared to previous methods, retrievals employing the proposed matching methodology are faster and more consistent with human recognition of spatial objects. In addition these performance

  14. Shape: A 3D Modeling Tool for Astrophysics.

    PubMed

    Steffen, Wolfgang; Koning, Nicholas; Wenger, Stephan; Morisset, Christophe; Magnor, Marcus

    2011-04-01

    We present a flexible interactive 3D morpho-kinematical modeling application for astrophysics. Compared to other systems, our application reduces the restrictions on the physical assumptions, data type, and amount that is required for a reconstruction of an object's morphology. It is one of the first publicly available tools to apply interactive graphics to astrophysical modeling. The tool allows astrophysicists to provide a priori knowledge about the object by interactively defining 3D structural elements. By direct comparison of model prediction with observational data, model parameters can then be automatically optimized to fit the observation. The tool has already been successfully used in a number of astrophysical research projects.

  15. Seismic Imaging of Sandbox Models

    NASA Astrophysics Data System (ADS)

    Buddensiek, M. L.; Krawczyk, C. M.; Kukowski, N.; Oncken, O.

    2009-04-01

    Analog sandbox simulations have been applied to study structural geological processes to provide qualitative and quantitative insights into the evolution of mountain belts and basins. These sandbox simulations provide either two-dimensional and dynamic or pseudo-three-dimensional and static information. To extend the dynamic simulations to three dimensions, we combine the analog sandbox simulation techniques with seismic physical modeling of these sandbox models. The long-term objective of this approach is to image seismic and seismological events of static and actively deforming 3D analog models. To achieve this objective, a small-scale seismic apparatus, composed of a water tank, a PC control unit including piezo-electric transducers, and a positioning system, was built for laboratory use. For the models, we use granular material such as sand and glass beads, so that the simulations can evolve dynamically. The granular models are required to be completely water saturated so that the sources and receivers are directly and well coupled to the propagating medium. Ultrasonic source frequencies (˜500 kHz) corresponding to wavelengths ˜5 times the grain diameter are necessary to be able to resolve small scale structures. In three experiments of different two-layer models, we show that (1) interfaces of layers of granular materials can be resolved depending on the interface preparation more than on the material itself. Secondly, we show that the dilation between the sand grains caused by a string that has been pulled through the grains, simulating a shear zone, causes a reflection that can be detected in the seismic data. In the third model, we perform a seismic reflection survey across a model that contains both the prepared interface and a shear zone, and apply 2D-seismic reflection processing to improve the resolution. Especially for more complex models, the clarity and penetration depth need to be improved to study the evolution of geological structures in dynamic

  16. A spherical harmonics intensity model for 3D segmentation and 3D shape analysis of heterochromatin foci.

    PubMed

    Eck, Simon; Wörz, Stefan; Müller-Ott, Katharina; Hahn, Matthias; Biesdorf, Andreas; Schotta, Gunnar; Rippe, Karsten; Rohr, Karl

    2016-08-01

    The genome is partitioned into regions of euchromatin and heterochromatin. The organization of heterochromatin is important for the regulation of cellular processes such as chromosome segregation and gene silencing, and their misregulation is linked to cancer and other diseases. We present a model-based approach for automatic 3D segmentation and 3D shape analysis of heterochromatin foci from 3D confocal light microscopy images. Our approach employs a novel 3D intensity model based on spherical harmonics, which analytically describes the shape and intensities of the foci. The model parameters are determined by fitting the model to the image intensities using least-squares minimization. To characterize the 3D shape of the foci, we exploit the computed spherical harmonics coefficients and determine a shape descriptor. We applied our approach to 3D synthetic image data as well as real 3D static and real 3D time-lapse microscopy images, and compared the performance with that of previous approaches. It turned out that our approach yields accurate 3D segmentation results and performs better than previous approaches. We also show that our approach can be used for quantifying 3D shape differences of heterochromatin foci.

  17. 3D Seismic Reflection Data: Has the Geological Hubble Retained Its Focus?

    NASA Astrophysics Data System (ADS)

    Jackson, Christopher

    2016-04-01

    In their seminal paper in 2002, Joe Cartwright and Mads Huuse referred to 3D seismic reflection data as the 'Geological Hubble', illustrating how these data had the potential to revolutionise our understanding of the genesis and evolution of sedimentary basins. 14 years on, I will here outline just some of the key recent advances made in our understanding of basin structure and stratigraphy, focusing on: (i) the intrusion and extrusion of igneous rocks; (ii) salt tectonics, with particular emphasis on intrasalt structure and the kinematics and mechanics of diapirism; (iii) the geometry and growth of normal faults; and (iv) the structure and emplacement of mass-transport complexes (MTCs). I will stress that future advances at least partly relies on hydrocarbon exploration companies and government agencies continuing to make their data freely available via easy-to-access data portals. I will issue a clarion call to academics, stressing that 'geodynamicists', sedimentologists, structural geologists and geomorphologists, amongst others, can benefit from utilising what I believe are currently an underused data type.

  18. The benefits of enhanced integration capabilities in 3-D reservoir modelling and simulation

    SciTech Connect

    O`Rourke, S.T.; Ikwumonu, A.

    1996-12-31

    The use of proprietary, closely linked 3-D geological and reservoir simulation software has greatly enhanced the reservoir modelling process by enabling complete integration of geological and engineering data in a 3-D manner. The software were used to model and simulate a deltaic sandstone reservoir in the Nigerian Forcados Yokri field in order to describe the reservoir sweep pattern. A simple simulation of the reservoir was first carried out to identify the main controls on the reservoir performance, which in this case were the intra-reservoir shales. As they are the only baffles or barriers to flow, proper modelling of them was critical to achieving a history match. Well logs, 3-D seismic, limited core data and sequence stratigraphic concepts were used to define a three dimensional depositional model which was then used to guide the 3-D reservoir architecture modelling. The reservoir model was evaluated in the 3-D simulator and, when the initial model did not yield a proper match with the historical production data, alternative models were easily generated and simulated until an acceptable match was achieved. The result was a 10% increase in predicted ultimate recovery, a better understanding of the reservoir and an optimized reservoir depletion plan.

  19. 3D Printing of Biomolecular Models for Research and Pedagogy.

    PubMed

    Da Veiga Beltrame, Eduardo; Tyrwhitt-Drake, James; Roy, Ian; Shalaby, Raed; Suckale, Jakob; Pomeranz Krummel, Daniel

    2017-03-13

    The construction of physical three-dimensional (3D) models of biomolecules can uniquely contribute to the study of the structure-function relationship. 3D structures are most often perceived using the two-dimensional and exclusively visual medium of the computer screen. Converting digital 3D molecular data into real objects enables information to be perceived through an expanded range of human senses, including direct stereoscopic vision, touch, and interaction. Such tangible models facilitate new insights, enable hypothesis testing, and serve as psychological or sensory anchors for conceptual information about the functions of biomolecules. Recent advances in consumer 3D printing technology enable, for the first time, the cost-effective fabrication of high-quality and scientifically accurate models of biomolecules in a variety of molecular representations. However, the optimization of the virtual model and its printing parameters is difficult and time consuming without detailed guidance. Here, we provide a guide on the digital design and physical fabrication of biomolecule models for research and pedagogy using open source or low-cost software and low-cost 3D printers that use fused filament fabrication technology.

  20. Multicomponent, 3-D, and High-Resolution 2-D Seismic Characterization of Gas Hydrate Study Sites in the Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Haines, S. S.; Hart, P. E.; Ruppel, C. D.; Collett, T. S.; Shedd, W.; Lee, M. W.; Miller, J.

    2012-12-01

    High saturations of gas hydrates have been identified within coarse-grained sediments in the Green Canyon 955 and Walker Ridge 313 lease blocks of the deepwater northern Gulf of Mexico. The thickness, lateral extent, and hydrate saturations in these deposits are constrained by geological and geophysical data and state-of-the-art logging-while-drilling information obtained in multiple boreholes at each site during a 2009 expedition. Presently lacking are multicomponent seismic data that can provide a thorough understanding of the in-situ compressional and shear seismic properties of the hydrate-bearing sediments. Such data may represent an important tool for future characterization of gas hydrate resources. To address this data gap, the U.S. Geological Survey, the U.S. Department of Energy, and the Bureau of Ocean Energy Management will collaborate on a 20-day research expedition to acquire wide-angle ocean bottom seismometer and high-resolution vertical incidence 2-D seismic data at the study sites. In preparation for this mid-2013 expedition, we have analyzed existing industry 3-D seismic data, along with numerically modeled multicomponent data. The 3-D seismic data allow us to identify and rank specific survey targets and can be combined with the numerical modeling results to determine optimal survey line orientation and acquisition parameters. Together, these data also provide a more thorough understanding of the gas hydrate systems at these two sites.

  1. CO2 mass estimation visible in time-lapse 3D seismic data from a saline aquifer and uncertainties

    NASA Astrophysics Data System (ADS)

    Ivanova, A.; Lueth, S.; Bergmann, P.; Ivandic, M.

    2014-12-01

    At Ketzin (Germany) the first European onshore pilot scale project for geological storage of CO2 was initiated in 2004. This project is multidisciplinary and includes 3D time-lapse seismic monitoring. A 3D pre-injection seismic survey was acquired in 2005. Then CO2 injection into a sandstone saline aquifer started at a depth of 650 m in 2008. A 1st 3D seismic repeat survey was acquired in 2009 after 22 kilotons had been injected. The imaged CO2 signature was concentrated around the injection well (200-300 m). A 2nd 3D seismic repeat survey was acquired in 2012 after 61 kilotons had been injected. The imaged CO2 signature further extended (100-200 m). The injection was terminated in 2013. Totally 67 kilotons of CO2 were injected. Time-lapse seismic processing, petrophysical data and geophysical logging on CO2 saturation have allowed for an estimate of the amount of CO2 visible in the seismic data. This estimate is dependent upon a choice of a number of parameters and contains a number of uncertainties. The main uncertainties are following. The constant reservoir porosity and CO2 density used for the estimation are probably an over-simplification since the reservoir is quite heterogeneous. May be velocity dispersion is present in the Ketzin reservoir rocks, but we do not consider it to be large enough that it could affect the mass of CO2 in our estimation. There are only a small number of direct petrophysical observations, providing a weak statistical basis for the determination of seismic velocities based on CO2 saturation and we have assumed that the petrophysical experiments were carried out on samples that are representative for the average properties of the whole reservoir. Finally, the most of the time delay values in the both 3D seismic repeat surveys within the amplitude anomaly are near the noise level of 1-2 ms, however a change of 1 ms in the time delay affects significantly the mass estimate, thus the choice of the time-delay cutoff is crucial. In spite

  2. Potential of 3D City Models to assess flood vulnerability

    NASA Astrophysics Data System (ADS)

    Schröter, Kai; Bochow, Mathias; Schüttig, Martin; Nagel, Claus; Ross, Lutz; Kreibich, Heidi

    2016-04-01

    Vulnerability, as the product of exposure and susceptibility, is a key factor of the flood risk equation. Furthermore, the estimation of flood loss is very sensitive to the choice of the vulnerability model. Still, in contrast to elaborate hazard simulations, vulnerability is often considered in a simplified manner concerning the spatial resolution and geo-location of exposed objects as well as the susceptibility of these objects at risk. Usually, area specific potential flood loss is quantified on the level of aggregated land-use classes, and both hazard intensity and resistance characteristics of affected objects are represented in highly simplified terms. We investigate the potential of 3D City Models and spatial features derived from remote sensing data to improve the differentiation of vulnerability in flood risk assessment. 3D City Models are based on CityGML, an application scheme of the Geography Markup Language (GML), which represents the 3D geometry, 3D topology, semantics and appearance of objects on different levels of detail. As such, 3D City Models offer detailed spatial information which is useful to describe the exposure and to characterize the susceptibility of residential buildings at risk. This information is further consolidated with spatial features of the building stock derived from remote sensing data. Using this database a spatially detailed flood vulnerability model is developed by means of data-mining. Empirical flood damage data are used to derive and to validate flood susceptibility models for individual objects. We present first results from a prototype application in the city of Dresden, Germany. The vulnerability modeling based on 3D City Models and remote sensing data is compared i) to the generally accepted good engineering practice based on area specific loss potential and ii) to a highly detailed representation of flood vulnerability based on a building typology using urban structure types. Comparisons are drawn in terms of

  3. Advanced Multivariate Inversion Techniques for High Resolution 3D Geophysical Modeling (Invited)

    NASA Astrophysics Data System (ADS)

    Maceira, M.; Zhang, H.; Rowe, C. A.

    2009-12-01

    We focus on the development and application of advanced multivariate inversion techniques to generate a realistic, comprehensive, and high-resolution 3D model of the seismic structure of the crust and upper mantle that satisfies several independent geophysical datasets. Building on previous efforts of joint invesion using surface wave dispersion measurements, gravity data, and receiver functions, we have added a fourth dataset, seismic body wave P and S travel times, to the simultaneous joint inversion method. We present a 3D seismic velocity model of the crust and upper mantle of northwest China resulting from the simultaneous, joint inversion of these four data types. Surface wave dispersion measurements are primarily sensitive to seismic shear-wave velocities, but at shallow depths it is difficult to obtain high-resolution velocities and to constrain the structure due to the depth-averaging of the more easily-modeled, longer-period surface waves. Gravity inversions have the greatest resolving power at shallow depths, and they provide constraints on rock density variations. Moreover, while surface wave dispersion measurements are primarily sensitive to vertical shear-wave velocity averages, body wave receiver functions are sensitive to shear-wave velocity contrasts and vertical travel-times. Addition of the fourth dataset, consisting of seismic travel-time data, helps to constrain the shear wave velocities both vertically and horizontally in the model cells crossed by the ray paths. Incorporation of both P and S body wave travel times allows us to invert for both P and S velocity structure, capitalizing on empirical relationships between both wave types’ seismic velocities with rock densities, thus eliminating the need for ad hoc assumptions regarding the Poisson ratios. Our new tomography algorithm is a modification of the Maceira and Ammon joint inversion code, in combination with the Zhang and Thurber TomoDD (double-difference tomography) program.

  4. 3D head model classification using optimized EGI

    NASA Astrophysics Data System (ADS)

    Tong, Xin; Wong, Hau-san; Ma, Bo

    2006-02-01

    With the general availability of 3D digitizers and scanners, 3D graphical models have been used widely in a variety of applications. This has led to the development of search engines for 3D models. Especially, 3D head model classification and retrieval have received more and more attention in view of their many potential applications in criminal identifications, computer animation, movie industry and medical industry. This paper addresses the 3D head model classification problem using 2D subspace analysis methods such as 2D principal component analysis (2D PCA[3]) and 2D fisher discriminant analysis (2DLDA[5]). It takes advantage of the fact that the histogram is a 2D image, and we can extract the most useful information from these 2D images to get a good result accordingingly. As a result, there are two main advantages: First, we can perform less calculation to obtain the same rate of classification; second, we can reduce the dimensionality more than PCA to obtain a higher efficiency.

  5. 3D MHD Models of Active Region Loops

    NASA Technical Reports Server (NTRS)

    Ofman, Leon

    2004-01-01

    Present imaging and spectroscopic observations of active region loops allow to determine many physical parameters of the coronal loops, such as the density, temperature, velocity of flows in loops, and the magnetic field. However, due to projection effects many of these parameters remain ambiguous. Three dimensional imaging in EUV by the STEREO spacecraft will help to resolve the projection ambiguities, and the observations could be used to setup 3D MHD models of active region loops to study the dynamics and stability of active regions. Here the results of 3D MHD models of active region loops are presented, and the progress towards more realistic 3D MHD models of active regions. In particular the effects of impulsive events on the excitation of active region loop oscillations, and the generation, propagations and reflection of EIT waves are shown. It is shown how 3D MHD models together with 3D EUV observations can be used as a diagnostic tool for active region loop physical parameters, and to advance the science of the sources of solar coronal activity.

  6. Integration of 3D photogrammetric outcrop models in the reservoir modelling workflow

    NASA Astrophysics Data System (ADS)

    Deschamps, Remy; Joseph, Philippe; Lerat, Olivier; Schmitz, Julien; Doligez, Brigitte; Jardin, Anne

    2014-05-01

    3D technologies are now widely used in geosciences to reconstruct outcrops in 3D. The technology used for the 3D reconstruction is usually based on Lidar, which provides very precise models. Such datasets offer the possibility to build well-constrained outcrop analogue models for reservoir study purposes. The photogrammetry is an alternate methodology which principles are based in determining the geometric properties of an object from photographic pictures taken from different angles. Outcrop data acquisition is easy, and this methodology allows constructing 3D outcrop models with many advantages such as: - light and fast acquisition, - moderate processing time (depending on the size of the area of interest), - integration of field data and 3D outcrops into the reservoir modelling tools. Whatever the method, the advantages of digital outcrop model are numerous as already highlighted by Hodgetts (2013), McCaffrey et al. (2005) and Pringle et al. (2006): collection of data from otherwise inaccessible areas, access to different angles of view, increase of the possible measurements, attributes analysis, fast rate of data collection, and of course training and communication. This paper proposes a workflow where 3D geocellular models are built by integrating all sources of information from outcrops (surface picking, sedimentological sections, structural and sedimentary dips…). The 3D geomodels that are reconstructed can be used at the reservoir scale, in order to compare the outcrop information with subsurface models: the detailed facies models of the outcrops are transferred into petrophysical and acoustic models, which are used to test different scenarios of seismic and fluid flow modelling. The detailed 3D models are also used to test new techniques of static reservoir modelling, based either on geostatistical approaches or on deterministic (process-based) simulation techniques. A modelling workflow has been designed to model reservoir geometries and properties from

  7. 3D model of amphioxus steroid receptor complexed with estradiol

    SciTech Connect

    Baker, Michael E.; Chang, David J.

    2009-08-28

    The origins of signaling by vertebrate steroids are not fully understood. An important advance was the report that an estrogen-binding steroid receptor [SR] is present in amphioxus, a basal chordate with a similar body plan as vertebrates. To investigate the evolution of estrogen-binding to steroid receptors, we constructed a 3D model of amphioxus SR complexed with estradiol. This 3D model indicates that although the SR is activated by estradiol, some interactions between estradiol and human ER{alpha} are not conserved in the SR, which can explain the low affinity of estradiol for the SR. These differences between the SR and ER{alpha} in the steroid-binding domain are sufficient to suggest that another steroid is the physiological regulator of the SR. The 3D model predicts that mutation of Glu-346 to Gln will increase the affinity of testosterone for amphioxus SR and elucidate the evolution of steroid-binding to nuclear receptors.

  8. Towards a Uniform 3-D Model of the Crust and Uppermost Mantle beneath Eastern China

    NASA Astrophysics Data System (ADS)

    Shen, W.; Ritzwoller, M. H.; Wang, W.; Kang, D.; Ning, J.; Zheng, Y.

    2014-12-01

    In the past decade, large and dense seismic arrays have been deployed across much of eastern China (e.g., the "CEArray" and the "China Array" deployed by the China Earthquake Administration (CEA), the NECESS Array deployed collaboratively by China, Japan and the US), which have been used to produce increasingly well resolved models of the crust and uppermost mantle at different scales. These models do not cover eastern China uniformly. In this presentation, we report on an effort to generate a complete 3-D model of the crust and uppermost mantle beneath eastern China using the state-of-art surface wave and body wave inversion techniques. Highlights of this effort include: 1) We collect ambient noise cross-correlations for over 1,800 seismic stations from the CEArray, China Array and multiple PASSCAL experiments in northeastern China/Tibet. Based on this data base, we perform a uniform surface wave tomography for the study area. 2) We collect P-wave receiver functions for over 1,000 stations in this area to further constrain crustal structures. 3) We adopt a Bayesian Monte Carlo inversion to the Rayleigh wave dispersion maps and produce a uniform 3-D model with uncertainties of the crust and uppermost mantle. 4) In the areas where receiver functions are collected, the surface wave inversion is replaced by a joint inversion of surface waves and receiver functions and the uncertainties of the Moho structure are significantly reduced. As more seismic arrays (e.g., the phase II of the China Array) are added to this area and other seismic observations (i.e., the Rayleigh wave H/V ratio) are obtained in the future, higher resolution models with increasingly reliable structural features will be assimilated into this 3-D model.

  9. Air Pollution Modeling Using A 3-d Hemispheric Nested Model

    NASA Astrophysics Data System (ADS)

    Frohn, L. M.; Christensen, J. H.; Brandt, J.; Hertel, O.

    A 3-D Eulerian transport-chemistry model based on modules and parameterisations from models developed over the last decade at the National Environmental Research Institute (DREAM, DEHM, ACDEP and DEOM) has been developed. The model is hemispheric with currently two nests implemented. The horizontal resolution in the mother domain is 150 km x 150 km. First nest covers the European area wit,h a 50 km x 50 km resolution, second covers the Scandinavian area with a resolution of 16.67 km x 16.67 km. The model employs a chemical scheme (originally 53 species) which has been modified to include a detailed description of the nitrogen chemistry. The concentration of air pollutants, such as sulfur and nitrogen in various forms, has been calculated with the model, applying no nesting as well as one and two nests. The calculated values have been validated by comparison to measurements from more than 200 EMEP monitoring stations. Furthermore deposition of nitrogen to marine waters has been estimated with the model. The goal is to obtain an improved description of spatial and temporal variations in the nutrient deposition to the marine environment. In the presentation the physics and chemistry of the model will be shortly described. Validations of the model calculations by comparison to EMEP measurements will be shown and discussed together with the results of the deposition calculations.

  10. Using 3D Glyph Visualization to Explore Real-time Seismic Data on Immersive and High-resolution Display Systems

    NASA Astrophysics Data System (ADS)

    Nayak, A. M.; Lindquist, K.; Kilb, D.; Newman, R.; Vernon, F.; Leigh, J.; Johnson, A.; Renambot, L.

    2003-12-01

    The study of time-dependent, three-dimensional natural phenomena like earthquakes can be enhanced with innovative and pertinent 3D computer graphics. Here we display seismic data as 3D glyphs (graphics primitives or symbols with various geometric and color attributes), allowing us to visualize the measured, time-dependent, 3D wave field from an earthquake recorded by a certain seismic network. In addition to providing a powerful state-of-health diagnostic of the seismic network, the graphical result presents an intuitive understanding of the real-time wave field that is hard to achieve with traditional 2D visualization methods. We have named these 3D icons `seismoglyphs' to suggest visual objects built from three components of ground motion data (north-south, east-west, vertical) recorded by a seismic sensor. A seismoglyph changes color with time, spanning the spectrum, to indicate when the seismic amplitude is largest. The spatial extent of the glyph indicates the polarization of the wave field as it arrives at the recording station. We compose seismoglyphs using the real time ANZA broadband data (http://www.eqinfo.ucsd.edu) to understand the 3D behavior of a seismic wave field in Southern California. Fifteen seismoglyphs are drawn simultaneously with a 3D topography map of Southern California, as real time data is piped into the graphics software using the Antelope system. At each station location, the seismoglyph evolves with time and this graphical display allows a scientist to observe patterns and anomalies in the data. The display also provides visual clues to indicate wave arrivals and ~real-time earthquake detection. Future work will involve adding phase detections, network triggers and near real-time 2D surface shaking estimates. The visuals can be displayed in an immersive environment using the passive stereoscopic Geowall (http://www.geowall.org). The stereographic projection allows for a better understanding of attenuation due to distance and earth

  11. Parallel Optimization of 3D Cardiac Electrophysiological Model Using GPU.

    PubMed

    Xia, Yong; Wang, Kuanquan; Zhang, Henggui

    2015-01-01

    Large-scale 3D virtual heart model simulations are highly demanding in computational resources. This imposes a big challenge to the traditional computation resources based on CPU environment, which already cannot meet the requirement of the whole computation demands or are not easily available due to expensive costs. GPU as a parallel computing environment therefore provides an alternative to solve the large-scale computational problems of whole heart modeling. In this study, using a 3D sheep atrial model as a test bed, we developed a GPU-based simulation algorithm to simulate the conduction of electrical excitation waves in the 3D atria. In the GPU algorithm, a multicellular tissue model was split into two components: one is the single cell model (ordinary differential equation) and the other is the diffusion term of the monodomain model (partial differential equation). Such a decoupling enabled realization of the GPU parallel algorithm. Furthermore, several optimization strategies were proposed based on the features of the virtual heart model, which enabled a 200-fold speedup as compared to a CPU implementation. In conclusion, an optimized GPU algorithm has been developed that provides an economic and powerful platform for 3D whole heart simulations.

  12. Parallel Optimization of 3D Cardiac Electrophysiological Model Using GPU

    PubMed Central

    Xia, Yong; Wang, Kuanquan; Zhang, Henggui

    2015-01-01

    Large-scale 3D virtual heart model simulations are highly demanding in computational resources. This imposes a big challenge to the traditional computation resources based on CPU environment, which already cannot meet the requirement of the whole computation demands or are not easily available due to expensive costs. GPU as a parallel computing environment therefore provides an alternative to solve the large-scale computational problems of whole heart modeling. In this study, using a 3D sheep atrial model as a test bed, we developed a GPU-based simulation algorithm to simulate the conduction of electrical excitation waves in the 3D atria. In the GPU algorithm, a multicellular tissue model was split into two components: one is the single cell model (ordinary differential equation) and the other is the diffusion term of the monodomain model (partial differential equation). Such a decoupling enabled realization of the GPU parallel algorithm. Furthermore, several optimization strategies were proposed based on the features of the virtual heart model, which enabled a 200-fold speedup as compared to a CPU implementation. In conclusion, an optimized GPU algorithm has been developed that provides an economic and powerful platform for 3D whole heart simulations. PMID:26581957

  13. Geospatial Modelling Approach for 3d Urban Densification Developments

    NASA Astrophysics Data System (ADS)

    Koziatek, O.; Dragićević, S.; Li, S.

    2016-06-01

    With growing populations, economic pressures, and the need for sustainable practices, many urban regions are rapidly densifying developments in the vertical built dimension with mid- and high-rise buildings. The location of these buildings can be projected based on key factors that are attractive to urban planners, developers, and potential buyers. Current research in this area includes various modelling approaches, such as cellular automata and agent-based modelling, but the results are mostly linked to raster grids as the smallest spatial units that operate in two spatial dimensions. Therefore, the objective of this research is to develop a geospatial model that operates on irregular spatial tessellations to model mid- and high-rise buildings in three spatial dimensions (3D). The proposed model is based on the integration of GIS, fuzzy multi-criteria evaluation (MCE), and 3D GIS-based procedural modelling. Part of the City of Surrey, within the Metro Vancouver Region, Canada, has been used to present the simulations of the generated 3D building objects. The proposed 3D modelling approach was developed using ESRI's CityEngine software and the Computer Generated Architecture (CGA) language.

  14. 3D Model Generation From the Engineering Drawing

    NASA Astrophysics Data System (ADS)

    Vaský, Jozef; Eliáš, Michal; Bezák, Pavol; Červeňanská, Zuzana; Izakovič, Ladislav

    2010-01-01

    The contribution deals with the transformation of engineering drawings in a paper form into a 3D computer representation. A 3D computer model can be further processed in CAD/CAM system, it can be modified, archived, and a technical drawing can be then generated from it as well. The transformation process from paper form to the data one is a complex and difficult one, particularly owing to the different types of drawings, forms of displayed objects and encountered errors and deviations from technical standards. The algorithm for 3D model generating from an orthogonal vector input representing a simplified technical drawing of the rotational part is described in this contribution. The algorithm was experimentally implemented as ObjectARX application in the AutoCAD system and the test sample as the representation of the rotational part was used for verificaton.

  15. Space Partitioning for Privacy Enabled 3D City Models

    NASA Astrophysics Data System (ADS)

    Filippovska, Y.; Wichmann, A.; Kada, M.

    2016-10-01

    Due to recent technological progress, data capturing and processing of highly detailed (3D) data has become extensive. And despite all prospects of potential uses, data that includes personal living spaces and public buildings can also be considered as a serious intrusion into people's privacy and a threat to security. It becomes especially critical if data is visible by the general public. Thus, a compromise is needed between open access to data and privacy requirements which can be very different for each application. As privacy is a complex and versatile topic, the focus of this work particularly lies on the visualization of 3D urban data sets. For the purpose of privacy enabled visualizations of 3D city models, we propose to partition the (living) spaces into privacy regions, each featuring its own level of anonymity. Within each region, the depicted 2D and 3D geometry and imagery is anonymized with cartographic generalization techniques. The underlying spatial partitioning is realized as a 2D map generated as a straight skeleton of the open space between buildings. The resulting privacy cells are then merged according to the privacy requirements associated with each building to form larger regions, their borderlines smoothed, and transition zones established between privacy regions to have a harmonious visual appearance. It is exemplarily demonstrated how the proposed method generates privacy enabled 3D city models.

  16. 3-D world modeling for an autonomous robot

    SciTech Connect

    Goldstein, M.; Pin, F.G.; Weisbin, C.R.

    1987-08-01

    This paper presents a methodology for a concise representation of the 3-D world model for a mobile robot, using range data. The process starts with the segmentation of the scene into ''objects'' that are given a unique label, based on principles of range continuity. Then the external surface of each object is partitioned into homogeneous surface patches. Contours of surface patches in 3-D space are identified by estimating the normal and curvature associated with each pixel. The resulting surface patches are then classified as planar, convex or concave. Since the world model uses a volumetric representation for the 3-D environment, planar surfaces are represented by thin volumetric polyhedra. Spherical and cylindrical surfaces are extracted and represented by appropriate volumetric primitives. All other surfaces are represented using the boolean union of spherical volumes (as described in a separate paper by the same authors). The result is a general, concise representation of the external 3-D world, which allows for efficient and robust 3-D object recognition. 20 refs., 14 figs.

  17. 3D elastic full waveform inversion: case study from a land seismic survey

    NASA Astrophysics Data System (ADS)

    Kormann, Jean; Marti, David; Rodriguez, Juan-Esteban; Marzan, Ignacio; Ferrer, Miguel; Gutierrez, Natalia; Farres, Albert; Hanzich, Mauricio; de la Puente, Josep; Carbonell, Ramon

    2016-04-01

    Full Waveform Inversion (FWI) is one of the most advanced processing methods that is recently reaching a mature state after years of solving theoretical and technical issues such as the non-uniqueness of the solution and harnessing the huge computational power required by realistic scenarios. BSIT (Barcelona Subsurface Imaging Tools, www.bsc.es/bsit) includes a FWI algorithm that can tackle with very complex problems involving large datasets. We present here the application of this system to a 3D dataset acquired to constrain the shallow subsurface. This is where the wavefield is the most complicated, because most of the wavefield conversions takes place in the shallow region and also because the media is much more laterally heterogeneous. With this in mind, at least isotropic elastic approximation would be suitable as kernel engine for FWI. The current study explores the possibilities to apply elastic isotropic FWI using only the vertical component of the recorded seismograms. The survey covers an area of 500×500 m2, and consists in a receivers grid of 10 m×20 m combined with a 250 kg accelerated weight-drop as source on a displaced grid of 20 m×20 m. One of the main challenges in this case study is the costly 3D modeling that includes topography and substantial free surface effects. FWI is applied to a data subset (shooting lines 4 to 12), and is performed for 3 frequencies ranging from 15 to 25 Hz. The starting models are obtained from travel-time tomography and the all computation is run on 75 nodes of Mare Nostrum supercomputer during 3 days. The resulting models provide a higher resolution of the subsurface structures, and show a good correlation with the available borehole measurements. FWI allows to extend in a reliable way this 1D knowledge (borehole) to 3D.

  18. Coronal roots of solar wind streams: 3-D MHD modeling

    NASA Technical Reports Server (NTRS)

    Pisanko, Yu. V.

    1995-01-01

    Weak (discontinuous) solutions of the 3-D MHD equations look like a promising tool to model the transonic solar wind with structural elements: current sheets, coronal plumes etc. Using the observational information about various coronal emissions one can include these structural elements into the 3-D MHD solar wind model by embedding the discontinuities of given type. Such 3-D MHD structured solar wind is calculated self-consistently: variants are examined via numerical experiments. In particular, the behavior of coronal plumes in the transonic solar wind flow, is modeled. The input information for numerical modeling (for example, the magnetic field map at the very base of the solar corona) can be adjusted so that fast stream arises over the center of the coronal hole, over the coronal hole boundaries and, even, over the region with closed magnetic topology. 3-D MHD equations have the analytical solution which can serve as a model of supersonic trans-alfvenic solar wind in the (5-20) solar radii heliocentric distance interval. The transverse, nonradial total (gas + magnetic field) pressure balance in the flow is the corner-stone of this solution. The solution describes the filamentation (ray-like structure of the solar corona) and streaming (formation of high-speed streams with velocities up to 800 km/sec) as a consequence of the magnetic field spatial inhomogeneous structure and trans-alfvenic character of the flow. The magnetic field works in the model as a 'controller' for the solar wind streaming and filamentation.

  19. 3D modeling of dual-gate FinFET.

    PubMed

    Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John

    2012-11-13

    The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 >Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.

  20. 3D shape decomposition and comparison for gallbladder modeling

    NASA Astrophysics Data System (ADS)

    Huang, Weimin; Zhou, Jiayin; Liu, Jiang; Zhang, Jing; Yang, Tao; Su, Yi; Law, Gim Han; Chui, Chee Kong; Chang, Stephen

    2011-03-01

    This paper presents an approach to gallbladder shape comparison by using 3D shape modeling and decomposition. The gallbladder models can be used for shape anomaly analysis and model comparison and selection in image guided robotic surgical training, especially for laparoscopic cholecystectomy simulation. The 3D shape of a gallbladder is first represented as a surface model, reconstructed from the contours segmented in CT data by a scheme of propagation based voxel learning and classification. To better extract the shape feature, the surface mesh is further down-sampled by a decimation filter and smoothed by a Taubin algorithm, followed by applying an advancing front algorithm to further enhance the regularity of the mesh. Multi-scale curvatures are then computed on the regularized mesh for the robust saliency landmark localization on the surface. The shape decomposition is proposed based on the saliency landmarks and the concavity, measured by the distance from the surface point to the convex hull. With a given tolerance the 3D shape can be decomposed and represented as 3D ellipsoids, which reveal the shape topology and anomaly of a gallbladder. The features based on the decomposed shape model are proposed for gallbladder shape comparison, which can be used for new model selection. We have collected 19 sets of abdominal CT scan data with gallbladders, some shown in normal shape and some in abnormal shapes. The experiments have shown that the decomposed shapes reveal important topology features.

  1. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    SciTech Connect

    Bjorn N. P. Paulsson

    2006-09-30

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to perform high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology has been hampered by the lack of acquisition technology necessary to record large volumes of high frequency, high signal-to-noise-ratio borehole seismic data. This project took aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array has removed the technical acquisition barrier for recording the data volumes necessary to do high resolution 3D VSP and 3D cross-well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that promise to take the gas industry to the next level in their quest for higher resolution images of deep and complex oil and gas reservoirs. Today only a fraction of the oil or gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of detailed compartmentalization of oil and gas reservoirs. In this project, we developed a 400 level 3C borehole seismic receiver array that allows for economic use of 3D borehole seismic imaging for reservoir characterization and monitoring. This new array has significantly increased the efficiency of recording large data volumes at sufficiently dense spatial sampling to resolve reservoir complexities. The receiver pods have been fabricated and tested to withstand high temperature (200 C/400 F) and high pressure (25,000 psi), so that they can operate in wells up to 7,620 meters (25,000 feet) deep. The receiver array is deployed on standard production or drill tubing. In combination with 3C surface seismic or 3C borehole seismic sources, the 400

  2. Enhanced visualization of angiograms using 3D models

    NASA Astrophysics Data System (ADS)

    Marovic, Branko S.; Duckwiler, Gary R.; Villablanca, Pablo; Valentino, Daniel J.

    1999-05-01

    The 3D visualization of intracranial vasculature can facilitate the planning of endovascular therapy and the evaluation of interventional result. To create 3D visualizations, volumetric datasets from x-ray computed tomography angiography (CTA) and magnetic resonance angiography (MRA) are commonly rendered using maximum intensity projection (MIP), volume rendering, or surface rendering techniques. However, small aneurysms and mild stenoses are very difficult to detect using these methods. Furthermore, the instruments used during endovascular embolization or surgical treatment produce artifacts that typically make post-intervention CTA inapplicable, and the presence of magnetic material prohibits the use of MRA. Therefore, standard digital angiography is typically used. In order to address these problems, we developed a visualization and modeling system that displays 2D and 3D angiographic images using a simple Web-based interface. Polygonal models of vasculature were generated from CT and MR data using 3D segmentation of bones and vessels and polygonal surface extraction and simplification. A web-based 3D environment was developed for interactive examination of reconstructed surface models, creation of oblique cross- sections and maximum intensity projections, and distance measurements and annotations. This environment uses a multi- tier client/server approach employing VRML and Java. The 3D surface model and angiographic images can be aligned and displayed simultaneously to permit better perception of complex vasculature and to determine optical viewing positions and angles before starting an angiographic sessions. Polygonal surface reconstruction allows interactive display of complex spatial structures on inexpensive platforms such as personal computers as well as graphic workstations. The aneurysm assessment procedure demonstrated the utility of web-based technology for clinical visualization. The resulting system facilitated the treatment of serious vascular

  3. 3-D QSAutogrid/R: an alternative procedure to build 3-D QSAR models. Methodologies and applications.

    PubMed

    Ballante, Flavio; Ragno, Rino

    2012-06-25

    Since it first appeared in 1988 3-D QSAR has proved its potential in the field of drug design and activity prediction. Although thousands of citations now exist in 3-D QSAR, its development was rather slow with the majority of new 3-D QSAR applications just extensions of CoMFA. An alternative way to build 3-D QSAR models, based on an evolution of software, has been named 3-D QSAutogrid/R and has been developed to use only software freely available to academics. 3-D QSAutogrid/R covers all the main features of CoMFA and GRID/GOLPE with implementation by multiprobe/multiregion variable selection (MPGRS) that improves the simplification of interpretation of the 3-D QSAR map. The methodology is based on the integration of the molecular interaction fields as calculated by AutoGrid and the R statistical environment that can be easily coupled with many free graphical molecular interfaces such as UCSF-Chimera, AutoDock Tools, JMol, and others. The description of each R package is reported in detail, and, to assess its validity, 3-D QSAutogrid/R has been applied to three molecular data sets of which either CoMFA or GRID/GOLPE models were reported in order to compare the results. 3-D QSAutogrid/R has been used as the core engine to prepare more that 240 3-D QSAR models forming the very first 3-D QSAR server ( www.3d-qsar.com ) with its code freely available through R-Cran distribution.

  4. Improving Semantic Updating Method on 3d City Models Using Hybrid Semantic-Geometric 3d Segmentation Technique

    NASA Astrophysics Data System (ADS)

    Sharkawi, K.-H.; Abdul-Rahman, A.

    2013-09-01

    Cities and urban areas entities such as building structures are becoming more complex as the modern human civilizations continue to evolve. The ability to plan and manage every territory especially the urban areas is very important to every government in the world. Planning and managing cities and urban areas based on printed maps and 2D data are getting insufficient and inefficient to cope with the complexity of the new developments in big cities. The emergence of 3D city models have boosted the efficiency in analysing and managing urban areas as the 3D data are proven to represent the real world object more accurately. It has since been adopted as the new trend in buildings and urban management and planning applications. Nowadays, many countries around the world have been generating virtual 3D representation of their major cities. The growing interest in improving the usability of 3D city models has resulted in the development of various tools for analysis based on the 3D city models. Today, 3D city models are generated for various purposes such as for tourism, location-based services, disaster management and urban planning. Meanwhile, modelling 3D objects are getting easier with the emergence of the user-friendly tools for 3D modelling available in the market. Generating 3D buildings with high accuracy also has become easier with the availability of airborne Lidar and terrestrial laser scanning equipments. The availability and accessibility to this technology makes it more sensible to analyse buildings in urban areas using 3D data as it accurately represent the real world objects. The Open Geospatial Consortium (OGC) has accepted CityGML specifications as one of the international standards for representing and exchanging spatial data, making it easier to visualize, store and manage 3D city models data efficiently. CityGML able to represents the semantics, geometry, topology and appearance of 3D city models in five well-defined Level-of-Details (LoD), namely LoD0

  5. Enhanced LOD Concepts for Virtual 3d City Models

    NASA Astrophysics Data System (ADS)

    Benner, J.; Geiger, A.; Gröger, G.; Häfele, K.-H.; Löwner, M.-O.

    2013-09-01

    Virtual 3D city models contain digital three dimensional representations of city objects like buildings, streets or technical infrastructure. Because size and complexity of these models continuously grow, a Level of Detail (LoD) concept effectively supporting the partitioning of a complete model into alternative models of different complexity and providing metadata, addressing informational content, complexity and quality of each alternative model is indispensable. After a short overview on various LoD concepts, this paper discusses the existing LoD concept of the CityGML standard for 3D city models and identifies a number of deficits. Based on this analysis, an alternative concept is developed and illustrated with several examples. It differentiates between first, a Geometric Level of Detail (GLoD) and a Semantic Level of Detail (SLoD), and second between the interior building and its exterior shell. Finally, a possible implementation of the new concept is demonstrated by means of an UML model.

  6. Teaching the geological subsurface with 3D models

    NASA Astrophysics Data System (ADS)

    Thorpe, Steve; Ward, Emma

    2014-05-01

    3D geological models have great potential as a resource when teaching geological concepts as it allows the student to visualise and interrogate UK geology. They are especially useful when dealing with the conversion of 2D field, map and GIS outputs into three dimensional geological units, which is a common problem for many students. Today's earth science students use a variety of skills and processes during their learning experience including spatial thinking, image construction, detecting patterns, making predictions and deducing the orientation of themselves. 3D geological models can reinforce spatial thinking strategies and encourage students to think about processes and properties, in turn helping the student to recognise pre-learnt geological principles in the field and to convert what they see at the surface into a picture of what is going on at depth. The British Geological Survey (BGS) has been producing digital 3D geological models for over 10 years. The models produced are revolutionising the working practices, data standards and products of the BGS. Sharing our geoscience information with academia is highlighted throughout the BGS strategy as is instilling practical skills in future geoscience professionals, such as model building and interpretation. In 2009 a project was launched to investigate the potential of the models as a teaching resource. The study included justifying if and how the models help students to learn, how models have been used historically, and how other forms of modelling are being used today. BGS now produce 3D geological models for use by anyone teaching or learning geoscience. They incorporate educational strategies that will develop geospatial skills and alleviate potential problems that some students experience. They are contained within contemporary case studies and show standard geological concepts, structures, sedimentary rocks, cross sections and field techniques. 3D geological models of the Isle of Wight and Ingleborough

  7. New insights into the earliest Quaternary environments in the Central North Sea from 3D seismic

    NASA Astrophysics Data System (ADS)

    Lamb, Rachel; Huuse, Mads; Stewart, Margaret; Brocklehurst, Simon H.

    2014-05-01

    In the past the transition between an unconformable surface in the south to a conformable horizon towards the north has made identification and mapping the base-Quaternary in the central North Sea difficult (Sejrup et al 1991; Gatliff et al 1994). However recent integration of biostratigraphy, pollen analysis, paleomagnetism and amino acid analysis in the Dutch and Danish sectors (Rasmussen et al 2005; Kuhlmann et al 2006) has allowed greater confidence in the correlation to the region 3D seismic datasets and thus has allowed the base-Quaternary to be mapped across the entire basin. The base-Quaternary has been mapped using the PGS MegaSurvey dataset from wells in the Danish Sector along the initially unconformable horizon and down the delta front into the more conformable basin giving a high degree of confidence in the horizon pick. The revised base-Quaternary surface reaches a depth of 1248 ms TWT with an elongate basin shape which is significantly deeper than the traditionally mapped surface. Using RMS amplitudes and other seismic attributes the revised base-Quaternary has been investigated along the horizon and in time slice to interpret the environments of the earliest Quaternary prior to the onset of glaciation. Combined with analysis of aligned elongate furrows over 10 km long, 100 m wide and 100 m deep suggest a deep marine environment in an almost enclosed basin with persistent strong NW-SE bottom currents in the deepest parts. Pockmarks were formed by the escape of shallow gas on the sides of a small delta in the eastern part of the basin. The progradation of large deltas from both the north and south into the basin make up the majority of the deposition of sediment into the basin. Key Words: base-Quaternary; seismic interpretation; paleoenvironments References: Gatliff, R.W, Richards, P.C, Smith, K, Graham, C.C, McCormac, M, Smith, N.J.P, Long, D, Cameron, T.D.J, Evans, D, Stevenson, A.G, Bulat, J, Ritchie, J.D, (1994) 'United Kingdom offshore regional

  8. Modeling the Properties of 3D Woven Composites

    NASA Technical Reports Server (NTRS)

    Cox, Brian N.

    1995-01-01

    An extensive study has been completed of the internal geometry, the mechanisms of failure, and the micromechanics of local failure events in graphite/epoxy composites with three dimensional (3D) woven reinforcement. This work has led to the development of models for predicting elastic constants, strength, notch sensitivity, and fatigue life. A summary is presented here.

  9. Performance and Cognitive Assessment in 3-D Modeling

    ERIC Educational Resources Information Center

    Fahrer, Nolan E.; Ernst, Jeremy V.; Branoff, Theodore J.; Clark, Aaron C.

    2011-01-01

    The purpose of this study was to investigate identifiable differences between performance and cognitive assessment scores in a 3-D modeling unit of an engineering drafting course curriculum. The study aimed to provide further investigation of the need of skill-based assessments in engineering/technical graphics courses to potentially increase…

  10. Coarse-grained modeling of RNA 3D structure.

    PubMed

    Dawson, Wayne K; Maciejczyk, Maciej; Jankowska, Elzbieta J; Bujnicki, Janusz M

    2016-07-01

    Functional RNA molecules depend on three-dimensional (3D) structures to carry out their tasks within the cell. Understanding how these molecules interact to carry out their biological roles requires a detailed knowledge of RNA 3D structure and dynamics as well as thermodynamics, which strongly governs the folding of RNA and RNA-RNA interactions as well as a host of other interactions within the cellular environment. Experimental determination of these properties is difficult, and various computational methods have been developed to model the folding of RNA 3D structures and their interactions with other molecules. However, computational methods also have their limitations, especially when the biological effects demand computation of the dynamics beyond a few hundred nanoseconds. For the researcher confronted with such challenges, a more amenable approach is to resort to coarse-grained modeling to reduce the number of data points and computational demand to a more tractable size, while sacrificing as little critical information as possible. This review presents an introduction to the topic of coarse-grained modeling of RNA 3D structures and dynamics, covering both high- and low-resolution strategies. We discuss how physics-based approaches compare with knowledge based methods that rely on databases of information. In the course of this review, we discuss important aspects in the reasoning process behind building different models and the goals and pitfalls that can result.

  11. Assessment of 3D Models Used in Contours Studies

    ERIC Educational Resources Information Center

    Alvarez, F. J. Ayala; Parra, E. B. Blazquez; Tubio, F. Montes

    2015-01-01

    This paper presents an experimental research focusing on the view of first year students. The aim is to check the quality of implementing 3D models integrated in the curriculum. We search to determine students' preference between the various means facilitated in order to understand the given subject. Students have been respondents to prove the…

  12. Tracking people and cars using 3D modeling and CCTV.

    PubMed

    Edelman, Gerda; Bijhold, Jurrien

    2010-10-10

    The aim of this study was to find a method for the reconstruction of movements of people and cars using CCTV footage and a 3D model of the environment. A procedure is proposed, in which video streams are synchronized and displayed in a 3D model, by using virtual cameras. People and cars are represented by cylinders and boxes, which are moved in the 3D model, according to their movements as shown in the video streams. The procedure was developed and tested in an experimental setup with test persons who logged their GPS coordinates as a recording of the ground truth. Results showed that it is possible to implement this procedure and to reconstruct movements of people and cars from video recordings. The procedure was also applied to a forensic case. In this work we experienced that more situational awareness was created by the 3D model, which made it easier to track people on multiple video streams. Based on all experiences from the experimental set up and the case, recommendations are formulated for use in practice.

  13. Robust 3D reconstruction system for human jaw modeling

    NASA Astrophysics Data System (ADS)

    Yamany, Sameh M.; Farag, Aly A.; Tazman, David; Farman, Allan G.

    1999-03-01

    This paper presents a model-based vision system for dentistry that will replace traditional approaches used in diagnosis, treatment planning and surgical simulation. Dentistry requires accurate 3D representation of the teeth and jaws for many diagnostic and treatment purposes. For example orthodontic treatment involves the application of force systems to teeth over time to correct malocclusion. In order to evaluate tooth movement progress, the orthodontists monitors this movement by means of visual inspection, intraoral measurements, fabrication of plastic models, photographs and radiographs, a process which is both costly and time consuming. In this paper an integrate system has been developed to record the patient's occlusion using computer vision. Data is acquired with an intraoral video camera. A modified shape from shading (SFS) technique, using perspective projection and camera calibration, is used to extract accurate 3D information from a sequence of 2D images of the jaw. A new technique for 3D data registration, using a Grid Closest Point transform and genetic algorithms, is used to register the SFS output. Triangulization is then performed, and a solid 3D model is obtained via a rapid prototype machine.

  14. 3D Geological modelling - towards a European level infrastructure

    NASA Astrophysics Data System (ADS)

    Lee, Kathryn A.; van der Krogt, Rob; Busschers, Freek S.

    2013-04-01

    The joint European Geological Surveys are preparing the ground for a "European Geological Data Infrastructure" (EGDI), under the framework of the FP7-project EGDI-Scope. This scoping study, started in June 2012, for a pan-European e-Infrastructure is based on the successes of earlier joint projects including 'OneGeology-Europe' and aims to provide the backbone for serving interoperable, geological data currently held by European Geological Surveys. Also data from past, ongoing and future European projects will be incorporated. The scope will include an investigation of the functional and technical requirements for serving 3D geological models and will look to research the potential for providing a framework to integrate models at different scales, and form a structure for enabling the development of new and innovative model delivery mechanisms. The EGDI-scope project encourages pan-European inter-disciplinary collaboration between all European Geological Surveys. It aims to enhance emerging web based technologies that will facilitate the delivery of geological data to user communities involved in European policy making and international industry, but also to geoscientific research communities and the general public. Therefore, stakeholder input and communication is imperative to the success, as is the collaboration with all the Geological Surveys of Europe. The most important functional and technical requirements for delivery of such information at pan-European level will be derived from exchanges with relevant European stakeholder representatives and providers of geological data. For handling and delivering 3D geological model data the project will need to address a number of strategic issues: • Which are the most important issues and queries for the relevant stakeholders, requiring 3D geological models? How can this be translated to functional requirements for development and design of an integrated European application? • How to handle the very large

  15. Quasi-3D Multi-scale Modeling Framework Development

    NASA Astrophysics Data System (ADS)

    Arakawa, A.; Jung, J.

    2008-12-01

    When models are truncated in or near an energetically active range of the spectrum, model physics must be changed as the resolution changes. The model physics of GCMs and that of CRMs are, however, quite different from each other and at present there is no unified formulation of model physics that automatically provides transition between these model physics. The Quasi-3D (Q3D) Multi-scale Modeling Framework (MMF) is an attempt to bridge this gap. Like the recently proposed Heterogeneous Multiscale Method (HMM) (E and Engquist 2003), MMF combines a macroscopic model, GCM, and a microscopic model, CRM. Unlike the traditional multiscale methods such as the multi-grid and adapted mesh refinement techniques, HMM and MMF are for solving multi-physics problems. They share the common objective "to design combined macroscopic-microscopic computational methods that are much more efficient than solving the full microscopic model and at the same time give the information we need" (E et al. 2008). The question is then how to meet this objective in practice, which can be highly problem dependent. In HHM, the efficiency is gained typically by localization of the microscale problem. Following the pioneering work by Grabowski and Smolarkiewicz (1999) and Grabowski (2001), MMF takes advantage of the fact that 2D CRMs are reasonably successful in simulating deep clouds. In this approach, the efficiency is gained by sacrificing the three-dimensionality of cloud-scale motion. It also "localizes" the algorithm through embedding a CRM in each GCM grid box using cyclic boundary condition. The Q3D MMF is an attempt to reduce the expense due to these constraints by partially including the cloud-scale 3D effects and extending the CRM beyond individual GCM grid boxes. As currently formulated, the Q3D MMF is a 4D estimation/prediction framework that combines a GCM with a 3D anelastic cloud-resolving vector vorticity equation model (VVM) applied to a network of horizontal grids. The network

  16. Grid cells in 3-D: Reconciling data and models.

    PubMed

    Horiuchi, Timothy K; Moss, Cynthia F

    2015-12-01

    It is well documented that place cells and grid cells in echolocating bats show properties similar to those described in rodents, and yet, continuous theta-frequency oscillations, proposed to play a central role in grid/place cell formation, are not present in bat recordings. These comparative neurophysiological data have raised many questions about the role of theta-frequency oscillations in spatial memory and navigation. Additionally, spatial navigation in three-dimensions poses new challenges for the representation of space in neural models. Inspired by the literature on space representation in the echolocating bat, we have developed a nonoscillatory model of 3-D grid cell creation that shares many of the features of existing oscillatory-interference models. We discuss the model in the context of current knowledge of 3-D space representation and highlight directions for future research.

  17. RNA and protein 3D structure modeling: similarities and differences.

    PubMed

    Rother, Kristian; Rother, Magdalena; Boniecki, Michał; Puton, Tomasz; Bujnicki, Janusz M

    2011-09-01

    In analogy to proteins, the function of RNA depends on its structure and dynamics, which are encoded in the linear sequence. While there are numerous methods for computational prediction of protein 3D structure from sequence, there have been very few such methods for RNA. This review discusses template-based and template-free approaches for macromolecular structure prediction, with special emphasis on comparison between the already tried-and-tested methods for protein structure modeling and the very recently developed "protein-like" modeling methods for RNA. We highlight analogies between many successful methods for modeling of these two types of biological macromolecules and argue that RNA 3D structure can be modeled using "protein-like" methodology. We also highlight the areas where the differences between RNA and proteins require the development of RNA-specific solutions.

  18. Stereoscopic display of 3D models for design visualization

    NASA Astrophysics Data System (ADS)

    Gilson, Kevin J.

    2006-02-01

    Advances in display technology and 3D design visualization applications have made real-time stereoscopic visualization of architectural and engineering projects a reality. Parsons Brinkerhoff (PB) is a transportation consulting firm that has used digital visualization tools from their inception and has helped pioneer the application of those tools to large scale infrastructure projects. PB is one of the first Architecture/Engineering/Construction (AEC) firms to implement a CAVE- an immersive presentation environment that includes stereoscopic rear-projection capability. The firm also employs a portable stereoscopic front-projection system, and shutter-glass systems for smaller groups. PB is using commercial real-time 3D applications in combination with traditional 3D modeling programs to visualize and present large AEC projects to planners, clients and decision makers in stereo. These presentations create more immersive and spatially realistic presentations of the proposed designs. This paper will present the basic display tools and applications, and the 3D modeling techniques PB is using to produce interactive stereoscopic content. The paper will discuss several architectural and engineering design visualizations we have produced.

  19. 3-D HYDRODYNAMIC MODELING IN A GEOSPATIAL FRAMEWORK

    SciTech Connect

    Bollinger, J; Alfred Garrett, A; Larry Koffman, L; David Hayes, D

    2006-08-24

    3-D hydrodynamic models are used by the Savannah River National Laboratory (SRNL) to simulate the transport of thermal and radionuclide discharges in coastal estuary systems. Development of such models requires accurate bathymetry, coastline, and boundary condition data in conjunction with the ability to rapidly discretize model domains and interpolate the required geospatial data onto the domain. To facilitate rapid and accurate hydrodynamic model development, SRNL has developed a pre- and post-processor application in a geospatial framework to automate the creation of models using existing data. This automated capability allows development of very detailed models to maximize exploitation of available surface water radionuclide sample data and thermal imagery.

  20. Modeling of 3D Woven Composites Containing Multiple Delaminations

    DTIC Science & Technology

    2012-08-20

    researchers 3D woven composites shows better damage tolerance than laminated textile composites without z-yarns such as plain woven composites even...modeling of quasi-static short beam shear test of plain woven laminated composites. Cohesive elements were used in regions where transverse cracks and...Title ABSTRACT In this paper we present FE modeling of quasi-static short beam shear test of plain woven laminated composites. Cohesive elements were

  1. Next-generation seismic experiments - II: wide-angle, multi-azimuth, 3-D, full-waveform inversion of sparse field data

    NASA Astrophysics Data System (ADS)

    Morgan, Joanna; Warner, Michael; Arnoux, Gillean; Hooft, Emilie; Toomey, Douglas; VanderBeek, Brandon; Wilcock, William

    2016-02-01

    3-D full-waveform inversion (FWI) is an advanced seismic imaging technique that has been widely adopted by the oil and gas industry to obtain high-fidelity models of P-wave velocity that lead to improvements in migrated images of the reservoir. Most industrial applications of 3-D FWI model the acoustic wavefield, often account for the kinematic effect of anisotropy, and focus on matching the low-frequency component of the early arriving refractions that are most sensitive to P-wave velocity structure. Here, we have adopted the same approach in an application of 3-D acoustic, anisotropic FWI to an ocean-bottom-seismometer (OBS) field data set acquired across the Endeavour oceanic spreading centre in the northeastern Pacific. Starting models for P-wave velocity and anisotropy were obtained from traveltime tomography; during FWI, velocity is updated whereas anisotropy is kept fixed. We demonstrate that, for the Endeavour field data set, 3-D FWI is able to recover fine-scale velocity structure with a resolution that is 2-4 times better than conventional traveltime tomography. Quality assurance procedures have been employed to monitor each step of the workflow; these are time consuming but critical to the development of a successful inversion strategy. Finally, a suite of checkerboard tests has been performed which shows that the full potential resolution of FWI can be obtained if we acquire a 3-D survey with a slightly denser shot and receiver spacing than is usual for an academic experiment. We anticipate that this exciting development will encourage future seismic investigations of earth science targets that would benefit from the superior resolution offered by 3-D FWI.

  2. COMBINING A NEW 3-D SEISMIC S-WAVE PROPAGATION ANALYSIS FOR REMOTE FRACTURE DETECTION WITH A ROBUST SUBSURFACE MICROFRACTURE-BASED VERIFICATION TECHNIQUE

    SciTech Connect

    Bob Hardage; M.M. Backus; M.V. DeAngelo; R.J. Graebner; S.E. Laubach; Paul Murray

    2004-02-01

    Fractures within the producing reservoirs at McElroy Field could not be studied with the industry-provided 3C3D seismic data used as a cost-sharing contribution in this study. The signal-to-noise character of the converted-SV data across the targeted reservoirs in these contributed data was not adequate for interpreting azimuth-dependent data effects. After illustrating the low signal quality of the converted-SV data at McElroy Field, the seismic portion of this report abandons the McElroy study site and defers to 3C3D seismic data acquired across a different fractured carbonate reservoir system to illustrate how 3C3D seismic data can provide useful information about fracture systems. Using these latter data, we illustrate how fast-S and slow-S data effects can be analyzed in the prestack domain to recognize fracture azimuth, and then demonstrate how fast-S and slow-S data volumes can be analyzed in the poststack domain to estimate fracture intensity. In the geologic portion of the report, we analyze published regional stress data near McElroy Field and numerous formation multi-imager (FMI) logs acquired across McElroy to develop possible fracture models for the McElroy system. Regional stress data imply a fracture orientation different from the orientations observed in most of the FMI logs. This report culminates Phase 2 of the study, ''Combining a New 3-D Seismic S-Wave Propagation Analysis for Remote Fracture Detection with a Robust Subsurface Microfracture-Based Verification Technique''. Phase 3 will not be initiated because wells were to be drilled in Phase 3 of the project to verify the validity of fracture-orientation maps and fracture-intensity maps produced in Phase 2. Such maps cannot be made across McElroy Field because of the limitations of the available 3C3D seismic data at the depth level of the reservoir target.

  3. Geometric and Colour Data Fusion for Outdoor 3D Models

    PubMed Central

    Merchán, Pilar; Adán, Antonio; Salamanca, Santiago; Domínguez, Vicente; Chacón, Ricardo

    2012-01-01

    This paper deals with the generation of accurate, dense and coloured 3D models of outdoor scenarios from scanners. This is a challenging research field in which several problems still remain unsolved. In particular, the process of 3D model creation in outdoor scenes may be inefficient if the scene is digitalized under unsuitable technical (specific scanner on-board camera) and environmental (rain, dampness, changing illumination) conditions. We address our research towards the integration of images and range data to produce photorealistic models. Our proposal is based on decoupling the colour integration and geometry reconstruction stages, making them independent and controlled processes. This issue is approached from two different viewpoints. On the one hand, given a complete model (geometry plus texture), we propose a method to modify the original texture provided by the scanner on-board camera with the colour information extracted from external images taken at given moments and under specific environmental conditions. On the other hand, we propose an algorithm to directly assign external images onto the complete geometric model, thus avoiding tedious on-line calibration processes. We present the work conducted on two large Roman archaeological sites dating from the first century A.D., namely, the Theatre of Segobriga and the Fori Porticus of Emerita Augusta, both in Spain. The results obtained demonstrate that our approach could be useful in the digitalization and 3D modelling fields. PMID:22969327

  4. A method for building 3D models of barchan dunes

    NASA Astrophysics Data System (ADS)

    Nai, Yang; Li-lan, Su; Lin, Wan; Jie, Yang; Shi-yi, Chen; Wei-lu, Hu

    2016-01-01

    The distributions of barchan dunes are usually represented by digital terrain models (DTMs) overlaid with digital orthophoto maps. Given that most regions with barchan dues have low relief, a 3D map obtained from a DTM may ineffectively show the stereoscopic shape of each dune. The method of building 3D models of barchan dunes using existing modeling software seldom considers the geographical environment. As a result, barchan dune models are often inconsistent with actual DTMs and incompletely express the morphological characteristics of dunes. Manual construction of barchan dune models is also costly and time consuming. Considering these problems, the morphological characteristics of barchan dunes and the mathematical relationships between the morphological parameters of the dunes, such as length, height, and width, are analyzed in this study. The methods of extracting the morphological feature points of barchan dunes, calculating their morphological parameters and building dune outlines and skeleton lines based on the medial axes, are also presented. The dune outlines, skeleton lines, and part of the medial axes of dunes are used to construct a constrained triangulated irregular network. C# and ArcEngine are employed to build 3D models of barchan dunes automatically. Experimental results of a study conducted in Tengger Desert show that the method can be used to approximate the morphological characteristics of barchan dunes and is less time consuming than manual methods.

  5. Geometric and colour data fusion for outdoor 3D models.

    PubMed

    Merchán, Pilar; Adán, Antonio; Salamanca, Santiago; Domínguez, Vicente; Chacón, Ricardo

    2012-01-01

    This paper deals with the generation of accurate, dense and coloured 3D models of outdoor scenarios from scanners. This is a challenging research field in which several problems still remain unsolved. In particular, the process of 3D model creation in outdoor scenes may be inefficient if the scene is digitalized under unsuitable technical (specific scanner on-board camera) and environmental (rain, dampness, changing illumination) conditions. We address our research towards the integration of images and range data to produce photorealistic models. Our proposal is based on decoupling the colour integration and geometry reconstruction stages, making them independent and controlled processes. This issue is approached from two different viewpoints. On the one hand, given a complete model (geometry plus texture), we propose a method to modify the original texture provided by the scanner on-board camera with the colour information extracted from external images taken at given moments and under specific environmental conditions. On the other hand, we propose an algorithm to directly assign external images onto the complete geometric model, thus avoiding tedious on-line calibration processes. We present the work conducted on two large Roman archaeological sites dating from the first century A.D., namely, the Theatre of Segobriga and the Fori Porticus of Emerita Augusta, both in Spain. The results obtained demonstrate that our approach could be useful in the digitalization and 3D modelling fields.

  6. Total-Field Technique for 3-D Modeling of Short Period Teleseismic Waves

    NASA Astrophysics Data System (ADS)

    Monteiller, V.; Beller, S.; Operto, S.; Nissen-Meyer, T.; Tago Pacheco, J.; Virieux, J.

    2014-12-01

    The massive development of dense seismic arrays and the rapid increase in computing capacity allow today to consider application of full waveform inversion of teleseismic data for high-resolution lithospheric imaging. We present an hybrid numerical method that allows for the modellingof short period teleseismic waves in 3D lithospheric target with both the discontinuous Galerkin finite elements method and finite difference method, opening the possibility to perform waveform inversion of seismograms recorded by dense regional broadband arrays. However, despite the supercomputer ability, the forward-problem remains expensive at global scale for teleseismic configuration especially when 3D numerical methods are considered. In order to perform the forward problem in a reasonable amount of time, we reduce the computational domain in which full waveform modelling is performed. We define a 3D regional domain located below the seismological network that is embedded in a homogeneous background or axisymmetric model, in which the seismic wavefield can be computed efficiently. The background wavefield is used to compute the full wavefield in the 3D regional domain using the so-called total-field/scattered-field technique. This method relies on the decomposition of the wavefield into a background and a scattered wavefields. The computational domain is subdivided into three sub-domains: an outer domain formed by the perfectly-matched absorbing layers, an intermediate domain in which only the outgoing wavefield scattered by the lithospheric heterogeneities is computed, and the inner domain formed by the lithospheric target in which the full wavefield is computed. In this study, we shall present simulations in realistic lithospheric target when the axisymetric background wavefield is computed with the AxiSEM softwave and the 3D simulation in lithospheric target model is performed with the discontinuous Galerkin or finite difference method.

  7. Towards a 3d Spatial Urban Energy Modelling Approach

    NASA Astrophysics Data System (ADS)

    Bahu, J.-M.; Koch, A.; Kremers, E.; Murshed, S. M.

    2013-09-01

    Today's needs to reduce the environmental impact of energy use impose dramatic changes for energy infrastructure and existing demand patterns (e.g. buildings) corresponding to their specific context. In addition, future energy systems are expected to integrate a considerable share of fluctuating power sources and equally a high share of distributed generation of electricity. Energy system models capable of describing such future systems and allowing the simulation of the impact of these developments thus require a spatial representation in order to reflect the local context and the boundary conditions. This paper describes two recent research approaches developed at EIFER in the fields of (a) geo-localised simulation of heat energy demand in cities based on 3D morphological data and (b) spatially explicit Agent-Based Models (ABM) for the simulation of smart grids. 3D city models were used to assess solar potential and heat energy demand of residential buildings which enable cities to target the building refurbishment potentials. Distributed energy systems require innovative modelling techniques where individual components are represented and can interact. With this approach, several smart grid demonstrators were simulated, where heterogeneous models are spatially represented. Coupling 3D geodata with energy system ABMs holds different advantages for both approaches. On one hand, energy system models can be enhanced with high resolution data from 3D city models and their semantic relations. Furthermore, they allow for spatial analysis and visualisation of the results, with emphasis on spatially and structurally correlations among the different layers (e.g. infrastructure, buildings, administrative zones) to provide an integrated approach. On the other hand, 3D models can benefit from more detailed system description of energy infrastructure, representing dynamic phenomena and high resolution models for energy use at component level. The proposed modelling strategies

  8. 3-D model-based tracking for UAV indoor localization.

    PubMed

    Teulière, Céline; Marchand, Eric; Eck, Laurent

    2015-05-01

    This paper proposes a novel model-based tracking approach for 3-D localization. One main difficulty of standard model-based approach lies in the presence of low-level ambiguities between different edges. In this paper, given a 3-D model of the edges of the environment, we derive a multiple hypotheses tracker which retrieves the potential poses of the camera from the observations in the image. We also show how these candidate poses can be integrated into a particle filtering framework to guide the particle set toward the peaks of the distribution. Motivated by the UAV indoor localization problem where GPS signal is not available, we validate the algorithm on real image sequences from UAV flights.

  9. Parallel tempering and 3D spin glass models

    NASA Astrophysics Data System (ADS)

    Papakonstantinou, T.; Malakis, A.

    2014-03-01

    We review parallel tempering schemes and examine their main ingredients for accuracy and efficiency. We discuss two selection methods of temperatures and some alternatives for the exchange of replicas, including all-pair exchange methods. We measure specific heat errors and round-trip efficiency using the two-dimensional (2D) Ising model, and also test the efficiency for the ground state production in 3D spin glass models. We find that the optimization of the GS problem is highly influenced by the choice of the temperature range of the PT process. Finally, we present numerical evidence concerning the universality aspects of an anisotropic case of the 3D spin-glass model.

  10. Integration of 2D and 3D reflection seismic data with deep boreholes in the Kevitsa Ni-Cu-PGE deposit, northern Finland

    NASA Astrophysics Data System (ADS)

    Koivisto, Emilia; Malehmir, Alireza; Voipio, Teemu; Wijns, Chris

    2013-04-01

    create a 3D lithological and structural model for the architecture of the whole complex. The information on the extent of the ore-bearing Kevitsa intrusion can be used for more effective exploration in the area. The base of the intrusion is particularly clear in the northern and eastern sectors. Toward the east, the base is mostly defined by disruption of the reflectors internal to the intrusion. The 2D seismic data, which extend beyond the 3D seismic study, reveal that the prominent reflectors at the base of the intrusion continue deeper toward the south-southwest. This has been interpreted as a previously unknown southern continuation of the intrusion. Furthermore, the data reveal strong reflectors at the base of the intrusion that have been penetrated by two deep drill holes in the area. These drill holes reveal contact-type mineralization at the onset of the reflectors. Thus, the seismic data can be directly used for exploration of the contact-type mineralization.

  11. 3D Multispectral Light Propagation Model For Subcutaneous Veins Imaging

    SciTech Connect

    Paquit, Vincent C; Price, Jeffery R; Meriaudeau, Fabrice; Tobin Jr, Kenneth William

    2008-01-01

    In this paper, we describe a new 3D light propagation model aimed at understanding the effects of various physiological properties on subcutaneous vein imaging. In particular, we build upon the well known MCML (Monte Carlo Multi Layer) code and present a tissue model that improves upon the current state-of-the-art by: incorporating physiological variation, such as melanin concentration, fat content, and layer thickness; including veins of varying depth and diameter; using curved surfaces from real arm shapes; and modeling the vessel wall interface. We describe our model, present results from the Monte Carlo modeling, and compare these results with those obtained with other Monte Carlo methods.

  12. Generation and use of human 3D-CAD models

    NASA Astrophysics Data System (ADS)

    Grotepass, Juergen; Speyer, Hartmut; Kaiser, Ralf

    2002-05-01

    Individualized Products are one of the ten mega trends of the 21st Century with human modeling as the key issue for tomorrow's design and product development. The use of human modeling software for computer based ergonomic simulations within the production process increases quality while reducing costs by 30- 50 percent and shortening production time. This presentation focuses on the use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production. Today, the entire production chain can be designed, individualized models generated and analyzed in 3D computer environments. Anthropometric design for ergonomics is matched to human needs, thus preserving health. Ergonomic simulation includes topics as human vision, reachability, kinematics, force and comfort analysis and international design capabilities. In German more than 17 billions of Mark are moved to other industries, because clothes do not fit. Individual clothing tailored to the customer's preference means surplus value, pleasure and perfect fit. The body scanning technology is the key to generation and use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production.

  13. Method for modeling post-mortem biometric 3D fingerprints

    NASA Astrophysics Data System (ADS)

    Rajeev, Srijith; Shreyas, Kamath K. M.; Agaian, Sos S.

    2016-05-01

    Despite the advancements of fingerprint recognition in 2-D and 3-D domain, authenticating deformed/post-mortem fingerprints continue to be an important challenge. Prior cleansing and reconditioning of the deceased finger is required before acquisition of the fingerprint. The victim's finger needs to be precisely and carefully operated by a medium to record the fingerprint impression. This process may damage the structure of the finger, which subsequently leads to higher false rejection rates. This paper proposes a non-invasive method to perform 3-D deformed/post-mortem finger modeling, which produces a 2-D rolled equivalent fingerprint for automated verification. The presented novel modeling method involves masking, filtering, and unrolling. Computer simulations were conducted on finger models with different depth variations obtained from Flashscan3D LLC. Results illustrate that the modeling scheme provides a viable 2-D fingerprint of deformed models for automated verification. The quality and adaptability of the obtained unrolled 2-D fingerprints were analyzed using NIST fingerprint software. Eventually, the presented method could be extended to other biometric traits such as palm, foot, tongue etc. for security and administrative applications.

  14. 3D cartographic modeling of the Alpine arc

    NASA Astrophysics Data System (ADS)

    Vouillamoz, Naomi; Sue, Christian; Champagnac, Jean-Daniel; Calcagno, Philippe

    2012-12-01

    We built a 3D cartography of the Alpine arc, a highly non-cylindrical mountain belt, using the 3D GeoModeller of the BRGM (French geological survey). The model allows to handle the large-scale 3D structure of seventeen major crustal units of the belt (from the lower crust to the sedimentary cover nappes), and two main discontinuities (the Insubric Line and the Crustal Penninic Front). It provides a unique document to better understand their structural relationships and to produce new sections. The study area comprises the western Alpine arc, from the Jura to the Northwest, up to the Bergell granite intrusion and the Lepontine Dome to the East, and is limited to the South by the Ligurian basin. The model is limited vertically 10 km above sea level at the top, and the moho interface at the bottom. We discarded the structural relationships between the Alps sensus stricto and the surrounding geodynamic systems such as the Rhine graben or the connection with the Apennines. The 3D-model is based on the global integration of various data such as the DEM of the Alps, the moho isobaths, the simplified geological and tectonic maps of the belt, the crustal cross-sections ECORS-CROP and NFP-20, and complementary cross-sections specifically built to precise local complexities. The database has first been integrated in a GIS-project to prepare their implementation in the GeoModeller, by homogenizing the different spatial referencing systems. The global model is finally interpolated from all these data, using the potential field method. The final document is a new tri-dimensional cartography that would be used as input for further alpine studies.

  15. Computer power fathoms the depths: billion-bit data processors illuminate the subsurface. [3-D Seismic techniques

    SciTech Connect

    Ross, J.J.

    1985-01-01

    Some of the same space-age signal technology being used to track events 200 miles above the earth is helping petroleum explorationists track down oil and natural gas two miles and more down into the earth. The breakthroughs, which have come in a technique called three-dimensional seismic work, could change the complexion of exploration for oil and natural gas. Thanks to this 3-D seismic approach, explorationists can make dynamic maps of sites miles beneath the surface. Then explorationists can throw these maps on space-age computer systems and manipulate them every which way - homing in sharply on salt domes, faults, sands and traps associated with oil and natural gas. ''The 3-D seismic scene has exploded within the last two years,'' says, Peiter Tackenberg, Marathon technical consultant who deals with both domestic and international exploration. The 3-D technique has been around for more than a decade, he notes, but recent achievements in space-age computer hardware and software have unlocked its full potential.

  16. Reactivating of a mature oil field in the Finca-Yopales area, Venezuela, Using 3-D seismic

    SciTech Connect

    Sanchez, M.; Betancourt, H.

    1996-08-01

    The area of Finca-Yopales is located in the Eastern Venezuelan Basin in the Anzoategui State where Corpoven has the Trico and Yopales Norte fields. Based on the interpretation of 134 km{sup 2} of 3-D seismic and the geologic interpretation from 145 wells in the area, we define a better geological and structural model. We were also able to map 6 seismic reflectors corresponding to the units A8, F7, L4U and SI from the Oficina Formation, U2 top of Merecure Formation and the top of the Cretaceous, in order to generate a fault plane for all the area which was converted to depth with a lineal relationship which was obtained from wells available. From this interpretation we obtain the structural levels B4, J2, M1 and U2 which are references for the area, those being regional and trangressive events. The main feature of the structure is a high at the southeast of the area and three fault systems of Cretaceous, Miocene and post-Miocene age. This area has been exploited for a long time, having more than 93% of the inactive drilled wells. The total production up to April, 1995 is 59.14 MMbls; the Trico field is the most prolific, with more than 95% of the production. The sands L`s, U`s, O`s and S`s are the most prospective. This paper present the evaluation of the area and the analysis of the reservoir where we increased the computed reserves.

  17. Geometric and Textural Blending for 3D Model Stylization.

    PubMed

    Huang, YiJheng; Lin, Wen-Chieh; Yeh, I-Cheng; Lee, Tong-Yee

    2017-01-25

    Stylizing a 3D model with characteristic shapes or appearances is common in product design, particularly in the design of 3D model merchandise, such as souvenirs, toys, furniture, and stylized items. A model stylization approach is proposed in this study. The approach combines base and style models while preserving user-specified shape features of the base model and the attractive features of the style model with limited assistance from a user. The two models are first combined at the topological level. A tree-growing technique is utilized to search for all possible combinations of the two models. Second, the models are combined at textural and geometric levels by employing a morphing technique. Results show that the proposed approach generates various appealing models and allows users to control the diversity of the output models and adjust the blending degree between the base and style models. The results of this work are also experimentally compared with those of a recent work through a user study. The comparison indicates that our results are more appealing, feature-preserving, and reasonable than those of the compared previous study. The proposed system allows product designers to easily explore design possibilities and assists novice users in creating their own stylized models.

  18. An open-source Matlab code package for improved rank-reduction 3D seismic data denoising and reconstruction

    NASA Astrophysics Data System (ADS)

    Chen, Yangkang; Huang, Weilin; Zhang, Dong; Chen, Wei

    2016-10-01

    Simultaneous seismic data denoising and reconstruction is a currently popular research subject in modern reflection seismology. Traditional rank-reduction based 3D seismic data denoising and reconstruction algorithm will cause strong residual noise in the reconstructed data and thus affect the following processing and interpretation tasks. In this paper, we propose an improved rank-reduction method by modifying the truncated singular value decomposition (TSVD) formula used in the traditional method. The proposed approach can help us obtain nearly perfect reconstruction performance even in the case of low signal-to-noise ratio (SNR). The proposed algorithm is tested via one synthetic and field data examples. Considering that seismic data interpolation and denoising source packages are seldom in the public domain, we also provide a program template for the rank-reduction based simultaneous denoising and reconstruction algorithm by providing an open-source Matlab package.

  19. CityGML - Interoperable semantic 3D city models

    NASA Astrophysics Data System (ADS)

    Gröger, Gerhard; Plümer, Lutz

    2012-07-01

    CityGML is the international standard of the Open Geospatial Consortium (OGC) for the representation and exchange of 3D city models. It defines the three-dimensional geometry, topology, semantics and appearance of the most relevant topographic objects in urban or regional contexts. These definitions are provided in different, well-defined Levels-of-Detail (multiresolution model). The focus of CityGML is on the semantical aspects of 3D city models, its structures, taxonomies and aggregations, allowing users to employ virtual 3D city models for advanced analysis and visualization tasks in a variety of application domains such as urban planning, indoor/outdoor pedestrian navigation, environmental simulations, cultural heritage, or facility management. This is in contrast to purely geometrical/graphical models such as KML, VRML, or X3D, which do not provide sufficient semantics. CityGML is based on the Geography Markup Language (GML), which provides a standardized geometry model. Due to this model and its well-defined semantics and structures, CityGML facilitates interoperable data exchange in the context of geo web services and spatial data infrastructures. Since its standardization in 2008, CityGML has become used on a worldwide scale: tools from notable companies in the geospatial field provide CityGML interfaces. Many applications and projects use this standard. CityGML is also having a strong impact on science: numerous approaches use CityGML, particularly its semantics, for disaster management, emergency responses, or energy-related applications as well as for visualizations, or they contribute to CityGML, improving its consistency and validity, or use CityGML, particularly its different Levels-of-Detail, as a source or target for generalizations. This paper gives an overview of CityGML, its underlying concepts, its Levels-of-Detail, how to extend it, its applications, its likely future development, and the role it plays in scientific research. Furthermore, its

  20. Joint inversion of 3-D seismic, gravimetric and magnetotelluric data for sub-basalt imaging in the Faroe-Shetland Basin

    NASA Astrophysics Data System (ADS)

    Heincke, B.; Moorkamp, M.; Jegen, M.; Hobbs, R. W.

    2012-12-01

    Imaging of sub-basalt sediments with reflection seismic techniques is limited due to absorption, scattering and transmission effects and the presence of peg-leg multiples. Although many of the difficulties facing conventional seismic profiles can be overcome by recording long offset data resolution of sub-basalt sediments in seismic sections is typically still largely restricted. Therefore multi-parametric approaches in general and joint inversion strategies in particular (e.g. Colombo et al., 2008, Jordan et al., 2012) are considered as alternative to gain additional information from sub-basalt structures. Here, we combine in a 3-D joint inversion first-arrival time tomography, FTG gravity and MT data to identify the base basalt and resolve potential sediments underneath. For sub-basalt exploration the three methods complement each other such that the null space is reduced and significantly better resolved models can be obtained than would be possible by the individual methods: The seismic data gives a robust model for the supra-basalt sediments whilst the gravity field is dominated by the high density basalt and basement features. The MT on the other hand is sensitive to the conductivity in both the supra- and sub-basalt sediments. We will present preliminary individual and joint inversion result for a FTG, seismic and MT data set located in the Faroe-Shetland basin. Because the investigated area is rather large (~75 x 40 km) and the individual data sets are relatively huge, we use a joint inversion framework (see Moorkamp et al., 2011) which is designed to handle large amount of data/model parameters. This program has moreover the options to link the individual parameter models either petrophysically using fixed parameter relationships or structurally using the cross-gradient approach. The seismic data set consists of a pattern of 8 intersecting wide-angle seismic profiles with maximum offsets of up to ~24 km. The 3-D gravity data set (size :~ 30 x 30 km) is

  1. Seismic body-wave interferometry using noise autocorrelations for crustal structure and a tutorial on 3D seismic processing and imaging using Madagascar

    NASA Astrophysics Data System (ADS)

    Olejnik, Peter

    Seismic body-wave interferometry is applied to selected seismic stations from the USArray Earthscope Transportable Array (TA) by autocorrelating ambient seismic noise recordings to construct effective zero-offset reflection seismograms. The robustness of the auto-correlations of noise traces is first tested on a TA station in Nevada where body-wave reflections similar to those found in an earlier study are identified. This approach is then applied to several TA stations in the central U.S., and the results are compared with synthetic data. Different stacking time periods are then examined to find the shortest time intervals that provide stable correlation stacks. A tutorial on 3D seismic processing and imaging using the Madagascar open-source software package is next presented for educational purposes. The 3D Teapot Dome seismic data set is examined to illustrate the processing and imaging steps. A number of processing steps are applied to the data set, including amplitude gaining, muting, deconvolution, static corrections, velocity analysis, normal moveout (NMO) correction, and stacking. Post-stack time and depth migrations are then performed on the stacked data along with post-migration f-x deconvolution.

  2. Lattice percolation approach to 3D modeling of tissue aging

    NASA Astrophysics Data System (ADS)

    Gorshkov, Vyacheslav; Privman, Vladimir; Libert, Sergiy

    2016-11-01

    We describe a 3D percolation-type approach to modeling of the processes of aging and certain other properties of tissues analyzed as systems consisting of interacting cells. Lattice sites are designated as regular (healthy) cells, senescent cells, or vacancies left by dead (apoptotic) cells. The system is then studied dynamically with the ongoing processes including regular cell dividing to fill vacant sites, healthy cells becoming senescent or dying, and senescent cells dying. Statistical-mechanics description can provide patterns of time dependence and snapshots of morphological system properties. The developed theoretical modeling approach is found not only to corroborate recent experimental findings that inhibition of senescence can lead to extended lifespan, but also to confirm that, unlike 2D, in 3D senescent cells can contribute to tissue's connectivity/mechanical stability. The latter effect occurs by senescent cells forming the second infinite cluster in the regime when the regular (healthy) cell's infinite cluster still exists.

  3. The 3D model control of image processing

    NASA Technical Reports Server (NTRS)

    Nguyen, An H.; Stark, Lawrence

    1989-01-01

    Telerobotics studies remote control of distant robots by a human operator using supervisory or direct control. Even if the robot manipulators has vision or other senses, problems arise involving control, communications, and delay. The communication delays that may be expected with telerobots working in space stations while being controlled from an Earth lab have led to a number of experiments attempting to circumvent the problem. This delay in communication is a main motivating factor in moving from well understood instantaneous hands-on manual control to less well understood supervisory control; the ultimate step would be the realization of a fully autonomous robot. The 3-D model control plays a crucial role in resolving many conflicting image processing problems that are inherent in resolving in the bottom-up approach of most current machine vision processes. The 3-D model control approach is also capable of providing the necessary visual feedback information for both the control algorithms and for the human operator.

  4. Modeling 3D faces from samplings via compressive sensing

    NASA Astrophysics Data System (ADS)

    Sun, Qi; Tang, Yanlong; Hu, Ping

    2013-07-01

    3D data is easier to acquire for family entertainment purpose today because of the mass-production, cheapness and portability of domestic RGBD sensors, e.g., Microsoft Kinect. However, the accuracy of facial modeling is affected by the roughness and instability of the raw input data from such sensors. To overcome this problem, we introduce compressive sensing (CS) method to build a novel 3D super-resolution scheme to reconstruct high-resolution facial models from rough samples captured by Kinect. Unlike the simple frame fusion super-resolution method, this approach aims to acquire compressed samples for storage before a high-resolution image is produced. In this scheme, depth frames are firstly captured and then each of them is measured into compressed samples using sparse coding. Next, the samples are fused to produce an optimal one and finally a high-resolution image is recovered from the fused sample. This framework is able to recover 3D facial model of a given user from compressed simples and this can reducing storage space as well as measurement cost in future devices e.g., single-pixel depth cameras. Hence, this work can potentially be applied into future applications, such as access control system using face recognition, and smart phones with depth cameras, which need high resolution and little measure time.

  5. 3D magnetotelluric modelling of the Alnö alkaline and carbonatite ring complex, central Sweden

    NASA Astrophysics Data System (ADS)

    Yan, Ping; Andersson, Magnus; Kalscheuer, Thomas; García Juanatey, María A.; Malehmir, Alireza; Shan, Chunling; Pedersen, Laust B.; Almqvist, Bjarne S. G.

    2016-06-01

    Thirty-four broadband magnetotelluric stations were deployed across the Alnö alkaline and carbonatite ring intrusion in central Sweden. The measurements were designed such that both 2D models along existing seismic profiles and a 3D model can be constructed. Alnö Island and surrounding areas are densely populated and industrialized and in order to reduce the effect of noise, the remote reference technique was utilized in time series processing. Strike and dimensionality analyses together with the induction arrows show that there is no homogeneous regional strike direction in this area. Therefore, only the determinant of the impedance tensor was used for 2D inversion whereas all elements of the impedance tensor were used for 3D inversion. Representative rock samples were collected from existing outcrops and their resistivities were measured in the laboratory to facilitate interpretation of the inversion models. The results from these measurements show that coarse-grained (sövite, white color) and fine-grained (dark color) carbonatites are the most conductive and resistive rock types, respectively. In accordance with the interpretation of the reflection seismic images, the 2D and 3D resistivity models depict the caldera-related ring-type fault system and updoming faulted and fractured systems as major 10-500 Ωm conductors, extending down to about 3 km depth. A central ~ 4000 Ωm resistive unit at about 3 km depth appears to correspond to a solidified fossil magma chamber as speculated from the reflection seismic data and earlier field geological studies.

  6. Laplace-domain waveform modeling and inversion for the 3D acoustic-elastic coupled media

    NASA Astrophysics Data System (ADS)

    Shin, Jungkyun; Shin, Changsoo; Calandra, Henri

    2016-06-01

    Laplace-domain waveform inversion reconstructs long-wavelength subsurface models by using the zero-frequency component of damped seismic signals. Despite the computational advantages of Laplace-domain waveform inversion over conventional frequency-domain waveform inversion, an acoustic assumption and an iterative matrix solver have been used to invert 3D marine datasets to mitigate the intensive computing cost. In this study, we develop a Laplace-domain waveform modeling and inversion algorithm for 3D acoustic-elastic coupled media by using a parallel sparse direct solver library (MUltifrontal Massively Parallel Solver, MUMPS). We precisely simulate a real marine environment by coupling the 3D acoustic and elastic wave equations with the proper boundary condition at the fluid-solid interface. In addition, we can extract the elastic properties of the Earth below the sea bottom from the recorded acoustic pressure datasets. As a matrix solver, the parallel sparse direct solver is used to factorize the non-symmetric impedance matrix in a distributed memory architecture and rapidly solve the wave field for a number of shots by using the lower and upper matrix factors. Using both synthetic datasets and real datasets obtained by a 3D wide azimuth survey, the long-wavelength component of the P-wave and S-wave velocity models is reconstructed and the proposed modeling and inversion algorithm are verified. A cluster of 80 CPU cores is used for this study.

  7. 3D modelling of the Black Sea ecosystem

    NASA Astrophysics Data System (ADS)

    Capet, A.; Gregoire, M.; Beckers, J.-M.; Joassin, P.; Naithani, J.; Soetart, K.

    2009-04-01

    A coupled physical-biogeochemical model has been developed to simulate the ecosystem of the Black Sea at the end of the 80's when eutrophication and invasion by gelatinous organisms seriously affected the stability and dynamics of the system. The biogeochemical model describes the cycle of carbon, nitrogen, silicate, oxygen and phosphorus through the foodweb from bacteria to gelatinous carnivores and explicitly represents processes in the anoxic layer down to the bottom. For calibration and analyses purposes, the coupled model has first been run in 1D at several places in the Black Sea. The biogeochemical model involves some hundred parameters which have been first calibrated by hand using published values. Then, an identifiability analysis has been performed in order to determine a subset of 15 identifiable parameters. An automatic calibration subroutine has been used to fine tune these parameters. In 1D, the model solution exhibits a complex dynamics with several years of transient adjustment. This complexity is imparted by the explicit modelling of top predators. The model has been calibrated and validated using a large set of data available in the Black Sea TU Ocean Base. The calibrated biogeochemical model is implemented in a 3D hydrodynamical model of the Black Sea. Results of these 3D simulations will be presented and compared with maps of in-situ data reconstructed from available data base using the software DIVA (Data Interpolation and Variational analysis).

  8. West Flank Coso, CA FORGE 3D geologic model

    SciTech Connect

    Doug Blankenship

    2016-03-01

    This is an x,y,z file of the West Flank FORGE 3D geologic model. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.

  9. 3D-printer visualization of neuron models.

    PubMed

    McDougal, Robert A; Shepherd, Gordon M

    2015-01-01

    Neurons come in a wide variety of shapes and sizes. In a quest to understand this neuronal diversity, researchers have three-dimensionally traced tens of thousands of neurons; many of these tracings are freely available through online repositories like NeuroMorpho.Org and ModelDB. Tracings can be visualized on the computer screen, used for statistical analysis of the properties of different cell types, used to simulate neuronal behavior, and more. We introduce the use of 3D printing as a technique for visualizing traced morphologies. Our method for generating printable versions of a cell or group of cells is to expand dendrite and axon diameters and then to transform the tracing into a 3D object with a neuronal surface generating algorithm like Constructive Tessellated Neuronal Geometry (CTNG). We show that 3D printed cells can be readily examined, manipulated, and compared with other neurons to gain insight into both the biology and the reconstruction process. We share our printable models in a new database, 3DModelDB, and encourage others to do the same with cells that they generate using our code or other methods. To provide additional context, 3DModelDB provides a simulatable version of each cell, links to papers that use or describe it, and links to associated entries in other databases.

  10. 3D-printer visualization of neuron models

    PubMed Central

    McDougal, Robert A.; Shepherd, Gordon M.

    2015-01-01

    Neurons come in a wide variety of shapes and sizes. In a quest to understand this neuronal diversity, researchers have three-dimensionally traced tens of thousands of neurons; many of these tracings are freely available through online repositories like NeuroMorpho.Org and ModelDB. Tracings can be visualized on the computer screen, used for statistical analysis of the properties of different cell types, used to simulate neuronal behavior, and more. We introduce the use of 3D printing as a technique for visualizing traced morphologies. Our method for generating printable versions of a cell or group of cells is to expand dendrite and axon diameters and then to transform the tracing into a 3D object with a neuronal surface generating algorithm like Constructive Tessellated Neuronal Geometry (CTNG). We show that 3D printed cells can be readily examined, manipulated, and compared with other neurons to gain insight into both the biology and the reconstruction process. We share our printable models in a new database, 3DModelDB, and encourage others to do the same with cells that they generate using our code or other methods. To provide additional context, 3DModelDB provides a simulatable version of each cell, links to papers that use or describe it, and links to associated entries in other databases. PMID:26175684

  11. Right approach to 3D modeling using CAD tools

    NASA Astrophysics Data System (ADS)

    Baddam, Mounica Reddy

    The thesis provides a step-by-step methodology to enable an instructor dealing with CAD tools to optimally guide his/her students through an understandable 3D modeling approach which will not only enhance their knowledge about the tool's usage but also enable them to achieve their desired result in comparatively lesser time. In the known practical field, there is particularly very little information available to apply CAD skills to formal beginners' training sessions. Additionally, advent of new software in 3D domain cumulates updating into a more difficult task. Keeping up to the industry's advanced requirements emphasizes the importance of more skilled hands in the field of CAD development, rather than just prioritizing manufacturing in terms of complex software features. The thesis analyses different 3D modeling approaches specified to the varieties of CAD tools currently available in the market. Utilizing performance-time databases, learning curves have been generated to measure their performance time, feature count etc. Based on the results, improvement parameters have also been provided for (Asperl, 2005).

  12. Effective 3-D surface modeling for geographic information systems

    NASA Astrophysics Data System (ADS)

    Yüksek, K.; Alparslan, M.; Mendi, E.

    2016-01-01

    In this work, we propose a dynamic, flexible and interactive urban digital terrain platform with spatial data and query processing capabilities of geographic information systems, multimedia database functionality and graphical modeling infrastructure. A new data element, called Geo-Node, which stores image, spatial data and 3-D CAD objects is developed using an efficient data structure. The system effectively handles data transfer of Geo-Nodes between main memory and secondary storage with an optimized directional replacement policy (DRP) based buffer management scheme. Polyhedron structures are used in digital surface modeling and smoothing process is performed by interpolation. The experimental results show that our framework achieves high performance and works effectively with urban scenes independent from the amount of spatial data and image size. The proposed platform may contribute to the development of various applications such as Web GIS systems based on 3-D graphics standards (e.g., X3-D and VRML) and services which integrate multi-dimensional spatial information and satellite/aerial imagery.

  13. 3D Calculation of Seismic Wave Interaction with Topography and Near-surface Structures at the LSBB Underground Laboratory, Rustrel, France

    NASA Astrophysics Data System (ADS)

    Maufroy, E.; Gaffet, S.; Operto, S.; Cruz-Atienza, V. M.; Senechal, G.; Dietrich, M.; Zeyen, H.; Sardou, O.; Boyer, D.

    2008-12-01

    The understanding of seismic wave interaction with both topography and geological structures is one of a principal focus of seismic risk characterization. Seasonal or artificial variations of water (or more generally fluid or gas) saturation in the medium revealed by local variations of rheological parameters (VP, VS, QP, QS, and density) may strongly impact the seismic and the hydro-mechanical site response. The problem addressed here is the characterization of these potential site effects, which are of great interest in the context of underground storage and effects of anthropogenic structures. With the foregoing in mind, a seismic experiment was carried out in 2006 at the LSBB Underground Laboratory (http://lsbb.unice.fr), Rustrel, France. A total of 189 seismometers (3D 0.1 Hz Agecodagis) were spread on the surface of the massif with a slope of 30%, 150 vertical geophones (14 Hz) distributed along the roof of the 800 m long tunnel at LSBB. A two-dimensional profile of 100 shots (150 g equiv. TNT) were used for imaging the rheological properties of the subterranean karstic medium. A 3D P-velocity model was obtained from the reflection and surface to depth transmission P-wave travel times featuring the foregoing 2D tomographic profile. Main faults and P-wave velocities correlate well with the two main lithological formations (Barremian and Bedoulian limestones) [S.S.B.S. program, 1965]. As a preliminary step, finite difference modelling [Shake3D, Cruz-Atienza et al., 2007] using fixed VP/VS ratio provided a means for topographic site effect assessment. With these parameters, deduced mean amplification factors reach values from 3 to 6. There are shadow regions with low ground motion. There are also seismic lenses where seismic energy focusing occurs. These depend on the topography shape and relative source location. In a more realistic medium deduced from full waveform inversion [Operto et al., 2004], variations of VP/VS ratio and quality factors QP, QS, are

  14. Underwater 3d Modeling: Image Enhancement and Point Cloud Filtering

    NASA Astrophysics Data System (ADS)

    Sarakinou, I.; Papadimitriou, K.; Georgoula, O.; Patias, P.

    2016-06-01

    This paper examines the results of image enhancement and point cloud filtering on the visual and geometric quality of 3D models for the representation of underwater features. Specifically it evaluates the combination of effects from the manual editing of images' radiometry (captured at shallow depths) and the selection of parameters for point cloud definition and mesh building (processed in 3D modeling software). Such datasets, are usually collected by divers, handled by scientists and used for geovisualization purposes. In the presented study, have been created 3D models from three sets of images (seafloor, part of a wreck and a small boat's wreck) captured at three different depths (3.5m, 10m and 14m respectively). Four models have been created from the first dataset (seafloor) in order to evaluate the results from the application of image enhancement techniques and point cloud filtering. The main process for this preliminary study included a) the definition of parameters for the point cloud filtering and the creation of a reference model, b) the radiometric editing of images, followed by the creation of three improved models and c) the assessment of results by comparing the visual and the geometric quality of improved models versus the reference one. Finally, the selected technique is tested on two other data sets in order to examine its appropriateness for different depths (at 10m and 14m) and different objects (part of a wreck and a small boat's wreck) in the context of an ongoing research in the Laboratory of Photogrammetry and Remote Sensing.

  15. Using submarine landforms to investigate glacial history, chronology and evolution during the Late Cenozoic: A 3D seismic case study of the mid-Norwegian shelf.

    NASA Astrophysics Data System (ADS)

    Newton, Andrew; Huuse, Mads

    2014-05-01

    The mid-Norwegian continental shelf and its succession through time has in places preserved a detailed geomorphological record of glacial and interglacial ice dynamics. Most work has concentrated on the most recent glaciations and therefore the full extent and dynamics of older glaciations is poorly understood. In this work several 3D seismic volumes, from across the mid-Norwegian shelf, are used together to image the glacial-interglacial sequences and piece together a chronology of shelf edge glaciation throughout the Late Cenozoic up until the most recent Weichselian glaciation. The 3D seismic data are supplemented with a large number of 2D seismic profiles and oil industry boreholes are used for calibration and horizon dating. The work presented here will help in the effort to establish a better detailed and more tightly constrained chronology of the extent and timings of different glaciations throughout the Late Cenozoic. Developing a better chronology is of critical importance for helping to calibrate current models of ice sheet and landscape evolution so that contemporary changes may be better understood. The basic geology of the system shows a progradation of the shelf edge towards the basin. The stratigraphical succession comprises evidence for several erosional events associated with the Elsterian, Saalian and Weichselian glaciations during the mid- to late Pleistocene. At depth the pre-glacial Neogene deposits are characterized by widespread polygonal faulting. Within the 3D seismic blocks several glaciogenic structures are visible. Most notably these include an abundance of linear and curvilinear mega-scale glacial lineations, which reach lengths of over 50 km, and iceberg scours that vary in length from 100 m to over 7 km. An array of different sized channels offer insight into the flow characteristics of pro-glacial and subglacial regimes during previous glaciations. Lateral moraines are also present in the seismic data and help to delineate past

  16. 3D flare particle model for ShipIR/NTCS

    NASA Astrophysics Data System (ADS)

    Ramaswamy, Srinivasan; Vaitekunas, David A.

    2016-05-01

    A key component in any soft-kill response to an incoming guided missile is the flare /chaff decoy used to distract or seduce the seeker homing system away from the naval platform. This paper describes a new 3D flare particle model in the naval threat countermeasure simulator (NTCS) of the NATO-standard ship signature model (ShipIR), which provides independent control over the size and radial distribution of its signature. The 3D particles of each flare sub-munition are modelled stochastically and rendered using OpenGL z-buffering, 2D projection, and alpha-blending to produce a unique and time varying signature. A sensitivity analysis on each input parameter provides the data and methods needed to synthesize a model from an IR measurement of a decoy. The new model also eliminated artifacts and deficiencies in our previous model which prevented reliable tracks from the adaptive track gate algorithm already presented by Ramaswamy and Vaitekunas (2015). A sequence of scenarios are used to test and demonstrate the new flare model during a missile engagement.

  17. Modeling Extracellular Matrix Reorganization in 3D Environments

    PubMed Central

    Harjanto, Dewi; Zaman, Muhammad H.

    2013-01-01

    Extracellular matrix (ECM) remodeling is a key physiological process that occurs in a number of contexts, including cell migration, and is especially important for cellular form and function in three-dimensional (3D) matrices. However, there have been few attempts to computationally model how cells modify their environment in a manner that accounts for both cellular properties and the architecture of the surrounding ECM. To this end, we have developed and validated a novel model to simulate matrix remodeling that explicitly defines cells in a 3D collagenous matrix. In our simulation, cells can degrade, deposit, or pull on local fibers, depending on the fiber density around each cell. The cells can also move within the 3D matrix. Different cell phenotypes can be modeled by varying key cellular parameters. Using the model we have studied how two model cancer cell lines, of differing invasiveness, modify matrices with varying fiber density in their vicinity by tracking the metric of fraction of matrix occupied by fibers. Our results quantitatively demonstrate that in low density environments, cells deposit more collagen to uniformly increase fibril fraction. On the other hand, in higher density environments, the less invasive model cell line reduced the fibril fraction as compared to the highly invasive phenotype. These results show good qualitative and quantitative agreement with existing experimental literature. Our simulation is therefore able to function as a novel platform to provide new insights into the clinically relevant and physiologically critical process of matrix remodeling by helping identify critical parameters that dictate cellular behavior in complex native-like environments. PMID:23341900

  18. 3D statistical shape models incorporating 3D random forest regression voting for robust CT liver segmentation

    NASA Astrophysics Data System (ADS)

    Norajitra, Tobias; Meinzer, Hans-Peter; Maier-Hein, Klaus H.

    2015-03-01

    During image segmentation, 3D Statistical Shape Models (SSM) usually conduct a limited search for target landmarks within one-dimensional search profiles perpendicular to the model surface. In addition, landmark appearance is modeled only locally based on linear profiles and weak learners, altogether leading to segmentation errors from landmark ambiguities and limited search coverage. We present a new method for 3D SSM segmentation based on 3D Random Forest Regression Voting. For each surface landmark, a Random Regression Forest is trained that learns a 3D spatial displacement function between the according reference landmark and a set of surrounding sample points, based on an infinite set of non-local randomized 3D Haar-like features. Landmark search is then conducted omni-directionally within 3D search spaces, where voxelwise forest predictions on landmark position contribute to a common voting map which reflects the overall position estimate. Segmentation experiments were conducted on a set of 45 CT volumes of the human liver, of which 40 images were randomly chosen for training and 5 for testing. Without parameter optimization, using a simple candidate selection and a single resolution approach, excellent results were achieved, while faster convergence and better concavity segmentation were observed, altogether underlining the potential of our approach in terms of increased robustness from distinct landmark detection and from better search coverage.

  19. Digital 3D Borobudur - Integration of 3D surveying and modeling techniques

    NASA Astrophysics Data System (ADS)

    Suwardhi, D.; Menna, F.; Remondino, F.; Hanke, K.; Akmalia, R.

    2015-08-01

    The Borobudur temple (Indonesia) is one of the greatest Buddhist monuments in the world, now listed as an UNESCO World Heritage Site. The present state of the temple is the result of restorations after being exposed to natural disasters several times. Today there is still a growing rate of deterioration of the building stones whose causes need further researches. Monitoring programs, supported at institutional level, have been effectively executed to observe the problem. The paper presents the latest efforts to digitally document the Borobudur Temple and its surrounding area in 3D with photogrammetric techniques. UAV and terrestrial images were acquired to completely digitize the temple, produce DEM, orthoimages and maps at 1:100 and 1:1000 scale. The results of the project are now employed by the local government organizations to manage the heritage area and plan new policies for the conservation and preservation of the UNESCO site. In order to help data management and policy makers, a web-based information system of the heritage area was also built to visualize and easily access all the data and achieved 3D results.

  20. 3-D modelling of seamount topography from satellite altimetry

    SciTech Connect

    Baudry, N. ); Calmant, S. )

    1991-06-01

    The authors develop a complete set of algorithms to perform 3D modelling of seamount bathymetry from satellite altimetry. The first stage of the data processing consists in gridding the geoid: to account for the long wavelength errors geoid heights are first bias-adjusted at cross-overs. Then a collocation on a regular grid is performed, accounting for the altimeter errors. In a second stage, geoid heights are converted into bathymetry. No simplifying assumption on the shape and location of the bathymetry highs is necessary. Bathymetric uncertainties due to the data sampling and the parameters of the mechanical and crustal models are evaluated.

  1. 3D Numerical Simulations of the Breakout Model

    NASA Astrophysics Data System (ADS)

    Choe, G. S.; Cheng, C. Z.; Lee, J.; Lynch, B. J.; Antiochos, S. K.; DeVore, C. R.; Zurbuchen, T. H.

    2005-05-01

    We present the continuing progress of the numerical simulations of the breakout model for coronal mass ejection initiation. To validate the 3D spherical ARMS code we have run the 2.5D breakout problem and compare the eruption to the published 2D results. The ARMS 2.5D CME also forms a large magnetic island ahead of the erupting plasmoid due to the code's excellent maintenance of equatorial symmetry. Progress on the fully 3D breakout problem is also discussed. To build up enough magnetic free energy for an eruption the active region field must be strong with a steep gradient near the polarity inversion line and the shear must be highly concentrated there. This requires adaptive griding techniques. In the current simulation, the active region to background field ratio is 20-to-1 and the neutral line is long compared to the active region width. We present the evolution of this topology under Br-conserving shearing flow and discuss implications for a 3D eruption. This work is supported by NASA and ONR. BJL is supported by NASA GSRP grant NGT5-50453.

  2. Discrete Method of Images for 3D Radio Propagation Modeling

    NASA Astrophysics Data System (ADS)

    Novak, Roman

    2016-09-01

    Discretization by rasterization is introduced into the method of images (MI) in the context of 3D deterministic radio propagation modeling as a way to exploit spatial coherence of electromagnetic propagation for fine-grained parallelism. Traditional algebraic treatment of bounding regions and surfaces is replaced by computer graphics rendering of 3D reflections and double refractions while building the image tree. The visibility of reception points and surfaces is also resolved by shader programs. The proposed rasterization is shown to be of comparable run time to that of the fundamentally parallel shooting and bouncing rays. The rasterization does not affect the signal evaluation backtracking step, thus preserving its advantage over the brute force ray-tracing methods in terms of accuracy. Moreover, the rendering resolution may be scaled back for a given level of scenario detail with only marginal impact on the image tree size. This allows selection of scene optimized execution parameters for faster execution, giving the method a competitive edge. The proposed variant of MI can be run on any GPU that supports real-time 3D graphics.

  3. UCVM: An Open Source Software Package for Querying and Visualizing 3D Velocity Models

    NASA Astrophysics Data System (ADS)

    Gill, D.; Small, P.; Maechling, P. J.; Jordan, T. H.; Shaw, J. H.; Plesch, A.; Chen, P.; Lee, E. J.; Taborda, R.; Olsen, K. B.; Callaghan, S.

    2015-12-01

    Three-dimensional (3D) seismic velocity models provide foundational data for ground motion simulations that calculate the propagation of earthquake waves through the Earth. The Southern California Earthquake Center (SCEC) has developed the Unified Community Velocity Model (UCVM) package for both Linux and OS X. This unique framework provides a cohesive way for querying and visualizing 3D models. UCVM v14.3.0, supports many Southern California velocity models including CVM-S4, CVM-H 11.9.1, and CVM-S4.26. The last model was derived from 26 full-3D tomographic iterations on CVM-S4. Recently, UCVM has been used to deliver a prototype of a new 3D model of central California (CCA) also based on full-3D tomographic inversions. UCVM was used to provide initial plots of this model and will be used to deliver CCA to users when the model is publicly released. Visualizing models is also possible with UCVM. Integrated within the platform are plotting utilities that can generate 2D cross-sections, horizontal slices, and basin depth maps. UCVM can also export models in NetCDF format for easy import into IDV and ParaView. UCVM has also been prototyped to export models that are compatible with IRIS' new Earth Model Collaboration (EMC) visualization utility. This capability allows for user-specified horizontal slices and cross-sections to be plotted in the same 3D Earth space. UCVM was designed to help a wide variety of researchers. It is currently being use to generate velocity meshes for many SCEC wave propagation codes, including AWP-ODC-SGT and Hercules. It is also used to provide the initial input to SCEC's CyberShake platform. For those interested in specific data points, the software framework makes it easy to extract P and S wave propagation speeds and other material properties from 3D velocity models by providing a common interface through which researchers can query earth models for a given location and depth. Also included in the last release was the ability to add small

  4. 3-D Model of Earthquake Sources in the Los Angeles Basin, CA

    NASA Astrophysics Data System (ADS)

    Plesch, A.; Shaw, J. H.

    2001-12-01

    We present a digital 3d model of the major, seismogenic fault system in the Los Angeles basin. The model is a prototype for a community-based fault characterization effort initiated by the Southern California Earthquake Center, Phase 2 (SCEC2). Faults were selected by consensus within the SCEC2 community based on geologic relevance, perceived hazard, and quality of descriptive data. Our first iteration model was populated with most of the important faults and with the deformed basement surface, which represents the main velocity interface in the basin. Constraints on fault geometries and positions include surface traces, surficial neotectonic data, seismic reflection profiles, wells, cross-sections, hypocentral locations, and focal mechanisms. Accurate geospatial registration proved essential. We use advanced geometric modeling software to integrate these various geophysical and geologic data in a 3d space, and to interpolate and extrapolate the fault surfaces. The model describes the geometry of imbricated blind-thrust faults that underlie the northern Los Angeles basin (Puente Hills, Las Cienegas, San Vicente, Elysian Park), as well as the basin bounding structures including the Santa Monica, Sierra Madre, and Cucamonga systems. In the case of the Santa Monica thrust, the 3d construction suggests the presence of a previously undocumented blind extension of this system to the northeast, below the Hollywood fault, and perhaps coinciding in parts with the North Salt Lake fault. The model also describes the 3D geometry of the major strike-slip systems in the basin, including the Newport-Inglewood and Whittier faults. The model provides a medium to investigate the spatial and temporal interactions of these fault systems based on their precise 3D geometries.

  5. Importance of a 3D forward modeling tool for surface wave analysis methods

    NASA Astrophysics Data System (ADS)

    Pageot, Damien; Le Feuvre, Mathieu; Donatienne, Leparoux; Philippe, Côte; Yann, Capdeville

    2016-04-01

    Since a few years, seismic surface waves analysis methods (SWM) have been widely developed and tested in the context of subsurface characterization and have demonstrated their effectiveness for sounding and monitoring purposes, e.g., high-resolution tomography of the principal geological units of California or real time monitoring of the Piton de la Fournaise volcano. Historically, these methods are mostly developed under the assumption of semi-infinite 1D layered medium without topography. The forward modeli