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Sample records for 3-d fault geometry

  1. Imaging the 3D geometry of pseudotachylyte-bearing faults

    NASA Astrophysics Data System (ADS)

    Resor, Phil; Shervais, Katherine

    2013-04-01

    Dynamic friction experiments in granitoid or gabbroic rocks that achieve earthquake slip velocities reveal significant weakening by melt-lubrication of the sliding surfaces. Extrapolation of these experimental results to seismic source depths (> 7 km) suggests that the slip weakening distance (Dw) over which this transition occurs is < 10 cm. The physics of this lubrication in the presence of a fluid (melt) is controlled by surface micro-topography. In order to characterize fault surface microroughness and its evolution during dynamic slip events on natural faults, we have undertaken an analysis of three-dimensional (3D) fault surface microtopography and its causes on a suite of pseudotachylyte-bearing fault strands from the Gole Larghe fault zone, Italy. The solidification of frictional melt soon after seismic slip ceases "freezes in" earthquake source geometries, however it also precludes the development of extensive fault surface exposures that have enabled direct studies of fault surface roughness. We have overcome this difficulty by imaging the intact 3D geometry of the fault using high-resolution X-ray computed tomography (CT). We collected a suite of 2-3.5 cm diameter cores (2-8 cm long) from individual faults within the Gole Larghe fault zone with a range of orientations (+/- 45 degrees from average strike) and slip magnitudes (0-1 m). Samples were scanned at the University of Texas High Resolution X-ray CT Facility, using an Xradia MicroCT scanner with a 70 kV X-ray source. Individual voxels (3D pixels) are ~36 ?m across. Fault geometry is thus imaged over ~4 orders of magnitude from the micron scale up to ~Dw. Pseudotachylyte-bearing fault zones are imaged as tabular bodies of intermediate X-ray attenuation crosscutting high attenuation biotite and low attenuation quartz and feldspar of the surrounding tonalite. We extract the fault surfaces (contact between the pseudotachylyte bearing fault zone and the wall rock) using integrated manual mapping, automated edge detection, and statistical evaluation. This approach results in a digital elevation model for each side of the fault zone that we use to quantify melt thickness and volume as well as surface microroughness and explore the relationship between these properties and the geometry, slip magnitude, and wall rock mineralogy of the fault.

  2. 3-D Geometry of Active Deformation East of the San Andreas Fault Near Parkfield, California

    NASA Astrophysics Data System (ADS)

    Carena, S.

    2006-12-01

    The thrust-and-fold belt east of the San Andreas fault that extends from the Diablo Range to the Temblor Range has been studied in detail mostly at its toe, where a large amount of data is available from oil exploration. We focus more on the part of the belt closer to the San Andreas fault (SAF). We use earthquake data for the period 1980-2006 coupled with surface geology to examine the 3-D geometry of faults in the southernmost Diablo Range, in particular the SAF from just north of Parkfield to the end of the creeping section, and the faults immediately to the east of the SAF. We then combine the results of our study with existing detailed studies and recent earthquake data of the eastern part of the belt to produce a consistent structural model all the way to the San Joaquin basin. We identify from earthquake data an active reverse fault just east of the SAF that abuts the SAF near the bottom of the seismogenic crust (~15 km depth). This fault strikes parallel to the mountain ridge above it, diverges from the SAF from north to south just like the ridge does, and it steepens close to the surface in its southern half. It also matches a major mapped fault trace at the surface. The presence of this fault would explain why this particular ridge has significantly higher structural relief than the surrounding areas, with the Franciscan brought to the surface. At the western margin of the San Joaquin basin, earthquakes indicate the presence of faulting to at least 18 km depth, deeper than can be inferred from oil data alone. The 3-D shape of some of these structures is also illuminated by earthquakes. For example, the aftershocks associated with the 1985 Kettleman Hills earthquake delineate a ramp-flat structure that is clearly different and separate from the structure associated with the 1983 Coalinga event. In general, structures east of the SAF near Parkfield are west-rooting, steeply- dipping thrust faults oriented perpendicular to the regional compression. From double-difference relocated earthquakes we recognize joint-like structures forming a "sliced-bread" pattern in the SAF near Parkfield. These structures are at the resolution limit, but their orientation matches exactly the one predicted from the orientation of the stress field in this region and agrees with the early SAFOD results.

  3. Source Process of the 1923 Kanto Earthquake Using New Fault Geometry and 3-D Green's Functions

    NASA Astrophysics Data System (ADS)

    Kobayashi, R.; Koketsu, K.

    2005-12-01

    The September 1, 1923, Kanto earthquake caused severe damage and more than 100,000 fatalities in the Tokyo metropolitan area. This earthquake is an interplate event along the Sagami trough where the Philippine Sea plate is subducting beneath a continental plate. We have investigated the source process of this earthquake using the geodetic, teleseismic, and strong motion data (Kobayashi and Koketsu, 2005). The resultant slip distributions show that two asperities (areas of large slips) are located around the base of the Izu peninsula and the Uraga channel. In 2002 and 2003, four seismic surveys were carried out to determine crustal structures and fault locations in the Kanto region (Sato et al., 2005). The seismic reflections from the surface of the Philippine Sea slab suggested that the slab surface should be shallower than the previous models (e.g., Ishida, 1992; Matsu'ura et al., 1980). The fault model of Kobayashi and Koketsu (2005) was also based on Matsu'ura et al. (1980). In this study, we adopt new fault geometry consistent with the result of the reflection surveys and perform another source process inversion. The new slip distribution showed that the western asperity moved from the Uraga channel to the tip of the Miura peninsula, while the western asperity did not move considerably. Green's functions that Kobayashi and Koketsu (2005) used were calculated in a halfspace for geodetic data or in a 1-D model for strong motions. However, the real structure in the Kanto region is three-dimensionally complex as suggested by the geographical setting and seismic surveys. In fact, Kobayashi and Koketsu (2005) showed that the long coda of the observed seismogram at Hongo, Tokyo, was not reproduced in the synthetic one. The forward modeling with a 3-D structure (Sato et al., 1999) suggested that surface waves excited along the boundary between the Kanto mountains and Kanto basin can explain the large coda. Thus we calculate 3-D Green's functions for the strong motion at Hongo and geodetic data. The resultant slip distribution using 3-D Green's function for strong motion data is almost similar to that with 1-D Green's function. However, the coda in the synthetic seismogram was much improved, and the slip rate functions in western asperity became slightly simpler. The 3-D Green's functions for geodetic data also improved the results.

  4. 3D geometry of growth strata in a fault-propagation fold: insights into space-time evolution of the Crevillente Fault (Abanilla-Alicante sector), Betic Cordillera, Spain

    NASA Astrophysics Data System (ADS)

    Martin-Rojas, I.; Alfaro, P.; Estévez, A.

    2015-07-01

    This work presents a 3D geometric model of growth strata cropping out in a fault-propagation fold associated with the Crevillente Fault (Abanilla-Alicante sector) from the Bajo Segura Basin (eastern Betic Cordillera, southern Spain). The analysis of this 3D model enables us to unravel the along-strike and along-section variations of the growth strata, providing constraints to assess the fold development, and hence, the fault kinematic evolution in space and time. We postulate that the observed along-strike dip variations are related to lateral variation in fault displacement. Along-section variations of the progressive unconformity opening angles indicate greater fault slip in the upper Tortonian-Messinian time span; from the Messinian on, quantitative analysis of the unconformity indicate a constant or lower tectonic activity of the Crevillente Fault (Abanilla-Alicante sector); the minor abundance of striated pebbles in the Pliocene-Quaternary units could be interpreted as a decrease in the stress magnitude and consequently in the tectonic activity of the fault. At a regional scale, comparison of the growth successions cropping out in the northern and southern limits of the Bajo Segura Basin points to a southward migration of deformation in the basin. This means that the Bajo Segura Fault became active after the Crevillente Fault (Abanilla-Alicante sector), for which activity on the latter was probably decreasing according to our data. Consequently, we propose that the seismic hazard at the northern limit of the Bajo Segura Basin should be lower than at the southern limit.

  5. Discovering Structural Regularity in 3D Geometry

    PubMed Central

    Pauly, Mark; Mitra, Niloy J.; Wallner, Johannes; Pottmann, Helmut; Guibas, Leonidas J.

    2010-01-01

    We introduce a computational framework for discovering regular or repeated geometric structures in 3D shapes. We describe and classify possible regular structures and present an effective algorithm for detecting such repeated geometric patterns in point- or mesh-based models. Our method assumes no prior knowledge of the geometry or spatial location of the individual elements that define the pattern. Structure discovery is made possible by a careful analysis of pairwise similarity transformations that reveals prominent lattice structures in a suitable model of transformation space. We introduce an optimization method for detecting such uniform grids specifically designed to deal with outliers and missing elements. This yields a robust algorithm that successfully discovers complex regular structures amidst clutter, noise, and missing geometry. The accuracy of the extracted generating transformations is further improved using a novel simultaneous registration method in the spatial domain. We demonstrate the effectiveness of our algorithm on a variety of examples and show applications to compression, model repair, and geometry synthesis. PMID:21170292

  6. Fault compaction and overpressured faults: results from a 3-D model of a ductile fault zone

    NASA Astrophysics Data System (ADS)

    Fitzenz, D. D.; Miller, S. A.

    2003-10-01

    A model of a ductile fault zone is incorporated into a forward 3-D earthquake model to better constrain fault-zone hydraulics. The conceptual framework of the model fault zone was chosen such that two distinct parts are recognized. The fault core, characterized by a relatively low permeability, is composed of a coseismic fault surface embedded in a visco-elastic volume that can creep and compact. The fault core is surrounded by, and mostly sealed from, a high permeability damaged zone. The model fault properties correspond explicitly to those of the coseismic fault core. Porosity and pore pressure evolve to account for the viscous compaction of the fault core, while stresses evolve in response to the applied tectonic loading and to shear creep of the fault itself. A small diffusive leakage is allowed in and out of the fault zone. Coseismically, porosity is created to account for frictional dilatancy. We show in the case of a 3-D fault model with no in-plane flow and constant fluid compressibility, pore pressures do not drop to hydrostatic levels after a seismic rupture, leading to an overpressured weak fault. Since pore pressure plays a key role in the fault behaviour, we investigate coseismic hydraulic property changes. In the full 3-D model, pore pressures vary instantaneously by the poroelastic effect during the propagation of the rupture. Once the stress state stabilizes, pore pressures are incrementally redistributed in the failed patch. We show that the significant effect of pressure-dependent fluid compressibility in the no in-plane flow case becomes a secondary effect when the other spatial dimensions are considered because in-plane flow with a near-lithostatically pressured neighbourhood equilibrates at a pressure much higher than hydrostatic levels, forming persistent high-pressure fluid compartments. If the observed faults are not all overpressured and weak, other mechanisms, not included in this model, must be at work in nature, which need to be investigated. Significant leakage perpendicular to the fault strike (in the case of a young fault), or cracks hydraulically linking the fault core to the damaged zone (for a mature fault) are probable mechanisms for keeping the faults strong and might play a significant role in modulating fault pore pressures. Therefore, fault-normal hydraulic properties of fault zones should be a future focus of field and numerical experiments.

  7. 3D stochastic geophysical inversion for contact surface geometry

    E-print Network

    Farquharson, Colin G.

    3D stochastic geophysical inversion for contact surface geometry Peter G. Leli`evre1, Colin G) · There are benefits to performing geophysical forward and inverse modelling on fundamentally different wireframe model´orio Nacional 3D stochastic geophysical inversion for contact surface geometry (2 / 44) #12;2 minute summary

  8. Unit cell geometry of 3-D braided structures

    NASA Technical Reports Server (NTRS)

    Du, Guang-Wu; Ko, Frank K.

    1993-01-01

    The traditional approach used in modeling of composites reinforced by three-dimensional (3-D) braids is to assume a simple unit cell geometry of a 3-D braided structure with known fiber volume fraction and orientation. In this article, we first examine 3-D braiding methods in the light of braid structures, followed by the development of geometric models for 3-D braids using a unit cell approach. The unit cell geometry of 3-D braids is identified and the relationship of structural parameters such as yarn orientation angle and fiber volume fraction with the key processing parameters established. The limiting geometry has been computed by establishing the point at which yarns jam against each other. Using this factor makes it possible to identify the complete range of allowable geometric arrangements for 3-D braided preforms. This identified unit cell geometry can be translated to mechanical models which relate the geometrical properties of fabric preforms to the mechanical responses of composite systems.

  9. Geometry shapes 3-D earth models

    SciTech Connect

    1997-07-01

    There`s no guarantee a company will convert its geologic and geophysical information into an oil or gas bonanza, but technology has increased the odds of exploratory success in recent years. In particular, operating companies have made great strides in using seismic data to create 3-D computer models of oil- and gas-bearing subsurface formations, thanks to more powerful computers and increasingly sophisticated software. These 3-D models allow geoscientists and energy engineers to explore geological formations that once were considered too complex for accurate representation. That, in turn, allows energy companies to extract more oil and gas existing fields and discover new fields more economically.

  10. 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…

  11. Using 3D Geometric Models to Teach Spatial Geometry Concepts.

    ERIC Educational Resources Information Center

    Bertoline, Gary R.

    1991-01-01

    An explanation of 3-D Computer Aided Design (CAD) usage to teach spatial geometry concepts using nontraditional techniques is presented. The software packages CADKEY and AutoCAD are described as well as their usefulness in solving space geometry problems. (KR)

  12. Dynamic 3D simulations of earthquakes on en echelon faults

    USGS Publications Warehouse

    Harris, R.A.; Day, S.M.

    1999-01-01

    One of the mysteries of earthquake mechanics is why earthquakes stop. This process determines the difference between small and devastating ruptures. One possibility is that fault geometry controls earthquake size. We test this hypothesis using a numerical algorithm that simulates spontaneous rupture propagation in a three-dimensional medium and apply our knowledge to two California fault zones. We find that the size difference between the 1934 and 1966 Parkfield, California, earthquakes may be the product of a stepover at the southern end of the 1934 earthquake and show how the 1992 Landers, California, earthquake followed physically reasonable expectations when it jumped across en echelon faults to become a large event. If there are no linking structures, such as transfer faults, then strike-slip earthquakes are unlikely to propagate through stepovers >5 km wide. Copyright 1999 by the American Geophysical Union.

  13. Automatic visualization of 3D geometry contained in online databases

    NASA Astrophysics Data System (ADS)

    Zhang, Jie; John, Nigel W.

    2003-04-01

    In this paper, the application of the Virtual Reality Modeling Language (VRML) for efficient database visualization is analyzed. With the help of JAVA programming, three examples of automatic visualization from a database containing 3-D Geometry are given. The first example is used to create basic geometries. The second example is used to create cylinders with a defined start point and end point. The third example is used to processs data from an old copper mine complex in Cheshire, United Kingdom. Interactive 3-D visualization of all geometric data in an online database is achieved with JSP technology.

  14. Thermal 3D modeling system based on 3-view geometry

    NASA Astrophysics Data System (ADS)

    Yu, Sunjin; Kim, Joongrock; Lee, Sangyoun

    2012-11-01

    In this paper, we propose a novel thermal three-dimensional (3D) modeling system that includes 3D shape, visual, and thermal infrared information and solves a registration problem among these three types of information. The proposed system consists of a projector, a visual camera and, a thermal camera (PVT). To generate 3D shape information, we use a structured light technique, which consists of a visual camera and a projector. A thermal camera is added to the structured light system in order to provide thermal information. To solve the correspondence problem between the three sensors, we use three-view geometry. Finally, we obtain registered PVT data, which includes visual, thermal, and 3D shape information. Among various potential applications such as industrial measurements, biological experiments, military usage, and so on, we have adapted the proposed method to biometrics, particularly for face recognition. With the proposed method, we obtain multi-modal 3D face data that includes not only textural information but also data regarding head pose, 3D shape, and thermal information. Experimental results show that the performance of the proposed face recognition system is not limited by head pose variation which is a serious problem in face recognition.

  15. The Maradi fault zone: 3-D imagery of a classic wrench fault in Oman

    SciTech Connect

    Neuhaus, D. )

    1993-09-01

    The Maradi fault zone extends for almost 350 km in a north-northwest-south-southeast direction from the Oman Mountain foothills into the Arabian Sea, thereby dissecting two prolific hydrocarbon provinces, the Ghaba and Fahud salt basins. During its major Late Cretaceous period of movement, the Maradi fault zone acted as a left-lateral wrench fault. An early exploration campaign based on two-dimensional seismic targeted at fractured Cretaceous carbonates had mixed success and resulted in the discovery of one producing oil field. The structural complexity, rapidly varying carbonate facies, and uncertain fracture distribution prevented further drilling activity. In 1990 a three-dimensional (3-D) seismic survey covering some 500 km[sup 2] was acquired over the transpressional northern part of the Maradi fault zone. The good data quality and the focusing power of 3-D has enabled stunning insight into the complex structural style of a [open quotes]textbook[close quotes] wrench fault, even at deeper levels and below reverse faults hitherto unexplored. Subtle thickness changes within the carbonate reservoir and the unconformably overlying shale seal provided the tool for the identification of possible shoals and depocenters. Horizon attribute maps revealed in detail the various structural components of the wrench assemblage and highlighted areas of increased small-scale faulting/fracturing. The results of four recent exploration wells will be demonstrated and their impact on the interpretation discussed.

  16. Towards "realistic" fault zones in a 3D structure model of the Thuringian Basin, Germany

    NASA Astrophysics Data System (ADS)

    Kley, J.; Malz, A.; Donndorf, S.; Fischer, T.; Zehner, B.

    2012-04-01

    3D computer models of geological architecture are evolving into a standard tool for visualization and analysis. Such models typically comprise the bounding surfaces of stratigraphic layers and faults. Faults affect the continuity of aquifers and can themselves act as fluid conduits or barriers. This is one reason why a "realistic" representation of faults in 3D models is desirable. Still so, many existing models treat faults in a simplistic fashion, e.g. as vertical downward projections of fault traces observed at the surface. Besides being geologically and mechanically unreasonable, this also causes technical difficulties in the modelling workflow. Most natural faults are inclined and may change dips according to rock type or flatten into mechanically weak layers. Boreholes located close to a fault can therefore cross it at depth, resulting in stratigraphic control points allocated to the wrong block. Also, faults tend to split up into several branches, forming fault zones. Obtaining a more accurate representation of faults and fault zones is therefore challenging. We present work-in-progress from the Thuringian Basin in central Germany. The fault zone geometries are never fully constrained by data and must be extrapolated to depth. We use balancing of serial, parallel cross-sections to constrain subsurface extrapolations. The structure sections are checked for consistency by restoring them to an undeformed state. If this is possible without producing gaps or overlaps, the interpretation is considered valid (but not unique) for a single cross-section. Additional constraints are provided by comparison of adjacent cross-sections. Structures should change continuously from one section to another. Also, from the deformed and restored cross-sections we can measure the strain incurred during deformation. Strain should be compatible among the cross-sections: If at all, it should vary smoothly and systematically along a given fault zone. The stratigraphic contacts and faults in the resulting grid of parallel balanced sections are then interpolated into a gOcad model containing stratigraphic boundaries and faults as triangulated surfaces. The interpolation is also controlled by borehole data located off the sections and the surface traces of stratigraphic boundaries. We have written customized scripts to largely automatize this step, with particular attention to a seamless fit between stratigraphic surfaces and fault planes which share the same nodes and segments along their contacts. Additional attention was paid to the creation of a uniform triangulated grid with maximized angles. This ensures that uniform triangulated volumes can be created for further use in numerical flow modelling. An as yet unsolved problem is the implementation of the fault zones and their hydraulic properties in a large-scale model of the entire basin. Short-wavelength folds and subsidiary faults control which aquifers and seals are juxtaposed across the fault zones. It is impossible to include these structures in the regional model, but neglecting them would result in incorrect assessments of hydraulic links or barriers. We presently plan to test and calibrate the hydraulic properties of the fault zones in smaller, high-resolution models and then to implement geometrically simple "equivalent" fault zones with appropriate, variable transmissivities between specific aquifers.

  17. Simulation of human ischemic stroke in realistic 3D geometry

    NASA Astrophysics Data System (ADS)

    Dumont, Thierry; Duarte, Max; Descombes, Stéphane; Dronne, Marie-Aimée; Massot, Marc; Louvet, Violaine

    2013-06-01

    In silico research in medicine is thought to reduce the need for expensive clinical trials under the condition of reliable mathematical models and accurate and efficient numerical methods. In the present work, we tackle the numerical simulation of reaction-diffusion equations modeling human ischemic stroke. This problem induces peculiar difficulties like potentially large stiffness which stems from the broad spectrum of temporal scales in the nonlinear chemical source term as well as from the presence of steep spatial gradients in the reaction fronts, spatially very localized. Furthermore, simulations on realistic 3D geometries are mandatory in order to describe correctly this type of phenomenon. The main goal of this article is to obtain, for the first time, 3D simulations on realistic geometries and to show that the simulation results are consistent with those obtain in experimental studies or observed on MRI images in stroke patients. For this purpose, we introduce a new resolution strategy based mainly on time operator splitting that takes into account complex geometry coupled with a well-conceived parallelization strategy for shared memory architectures. We consider then a high order implicit time integration for the reaction and an explicit one for the diffusion term in order to build a time operator splitting scheme that exploits efficiently the special features of each problem. Thus, we aim at solving complete and realistic models including all time and space scales with conventional computing resources, that is on a reasonably powerful workstation. Consequently and as expected, 2D and also fully 3D numerical simulations of ischemic strokes for a realistic brain geometry, are conducted for the first time and shown to reproduce the dynamics observed on MRI images in stroke patients. Beyond this major step, in order to improve accuracy and computational efficiency of the simulations, we indicate how the present numerical strategy can be coupled with spatial adaptive multiresolution schemes. Preliminary results in the framework of simple geometries allow to assess the proposed strategy for further developments.

  18. Kinematics of a growth fault/raft system on the West African margin using 3-D restoration

    NASA Astrophysics Data System (ADS)

    Rouby, Delphine; Raillard, Stéphane; Guillocheau, François; Bouroullec, Renaud; Nalpas, Thierry

    2002-04-01

    The ability to quantify the movement history associated with growth structures is crucial in the understanding of fundamental processes such as the growth of folds or faults in 3-D. In this paper, we present an application of an original approach to restore in 3-D a listric growth fault system resulting from gravity-induced extension located on the West African margin. Our goal is to establish the 3-D structural framework and kinematics of the study area. We construct a 3-D geometrical model of the fault system (from 3-D seismic data), then restore six stratigraphic surfaces and reconstruct the 3-D geometry of the system at six incremental steps of its history. The evolution of the growth fault/raft system corresponds to the progressive separation of two rafts by regional extension, resulting in the development of an intervening basin located between them that evolved in three main stages: (1) the rise of an evaporite wall, (2) the development of a symmetric basin as the elevation of the diapir is reduced and buried, and (3) the development of asymmetric basins related to two systems of listric faults (the main fault F1 and the graben located between the rollovers and the lower raft). Important features of the growth fault/raft system could only be observed in 3-D and with increments of deformation restored. The rollover anticline (associated with the listric fault F1) is composed of two sub-units separated by an E-W oriented transverse graben indicating that the displacement field was divergent in map view. The rollover units are located within the overlap area of two fault systems and displays a 'mock-turtle' anticline structure. The seaward translation of the lower raft is associated with two successive vertical axis rotations in the opposite sense (clockwise then counter-clockwise by about 10°). This results from the fact that the two main fault systems developed successively. Fault system F1 formed during the Upper Albian, and the graben during the Cenomanian. Using a new approach of 3-D restoration, this study suggests a consistent solution for: (1) the processes of deformation of a fault system, (2) the faulting kinematics, and (3) the incremental steps of deformation.

  19. Characterization of shallow normal fault systems in unconsolidated sediments using 3-D ground penetrating radar (SE Vienna Basin, Austria)

    NASA Astrophysics Data System (ADS)

    Spahic, D.; Exner, U.; Behm, M.; Grasemann, B.; Haring, A.

    2009-04-01

    In a gravel pit at the eastern margin of the Eisenstadt Basin, a subbasin of Vienna Basin (Austria), a set of normal faults crosscuts a Middle Miocene succession consisting of gravel layers, sandy gravels, fine-grained sands and silts with variable thicknesses between 1 and 4 m. These mainly friable sediments are cut by a numerous N-S striking high angle normal faults of ca. 0.5 - 10m length, offsetting, dragging and tilting the sedimentary layering. Normal faults occur either as isolated planes, or as parallel sets of high-angle faults dipping to the West. The outcrop is situated in the hanging wall of a major normal fault with a vertical displacement of at least 40m, which was interpreted as listric fault associated with a rollover anticline (Decker & Peresson, 1996). The displacement magnitude varies significantly along individual faults from cm to a few meters. The strong displacement gradients along these short faults result in the formation of perturbation fields around them, which deflect the initially planar sedimentary marker beds in the vicinity of the faults producing a pronounced reverse fault drag. None of these short faults display listric geometries or are associated with low angle detachment horizons. The spatial orientation and distribution of the faults and the associated fault drag was mapped in detail on a 3D laser scan of the outcrop wall. In order to assess the 3D distribution and geometry of this fault system, a series of parallel GPR (ground penetrating radar) profiles were recorded with a low frequency antenna behind the well-studied outcrop wall. The profile data were interpolated into a 3D GPR cube. Faults with normal offset of ca. 0.5-1,5 m can be mapped by detailed correlation of conspicuous marker horizons. Additionally, the deflection of markers around the fault planes can be documented from the GPR dataset. Both outcrop and GPR data were compiled in a 3D structural model using Gocad (Paradigm). The detailed geometry of the sedimentary horizons, the normal fault system and the associated fault drag is used to infer the subsurface continuation of the major normal fault below. Kinematic reconstruction of the fault plane using the Coulomb Collapse Theory predicts a bending of the fault plane into a subhorizontal orientation at ~70 m below the outcrop level. It is important to note, that these kind of reconstruction techniques inherently assume a listric fault geometry and therefore will always result in extensional fault, which flatten at a certain depth. However, correlation of reconstructed detachment this level with outcrop observation in the same gravel pit strongly question the interpretation as a listric fault. Instead, we suggest that in analogy to the smaller sized structures in the hanging wall, the observed deflection of stratigraphic horizons could be caused by displacement gradients along the fault, and that the deflection of markers should be interpreted as large scale fault drag instead of a rollover anticline. Decker, K. & Peresson, H. 1996. Rollover and hanging-wall collapse during Sarmatian/Pannonian synsedimentary extension in the Eisenstadt Basin. Mitt. Ges. Geol. Bergbaustud. Österr. 41, 45-52.

  20. A linguistic geometry for 3D strategic planning

    NASA Technical Reports Server (NTRS)

    Stilman, Boris

    1995-01-01

    This paper is a new step in the development and application of the Linguistic Geometry. This formal theory is intended to discover the inner properties of human expert heuristics, which have been successful in a certain class of complex control systems, and apply them to different systems. In this paper we investigate heuristics extracted in the form of hierarchical networks of planning paths of autonomous agents. Employing Linguistic Geometry tools the dynamic hierarchy of networks is represented as a hierarchy of formal attribute languages. The main ideas of this methodology are shown in this paper on the new pilot example of the solution of the extremely complex 3D optimization problem of strategic planning for the space combat of autonomous vehicles. This example demonstrates deep and highly selective search in comparison with conventional search algorithms.

  1. 3-D GPR data analysis for high-resolution imaging of shallow subsurface faults: the Mt Vettore case study (Central Apennines, Italy)

    NASA Astrophysics Data System (ADS)

    Ercoli, Maurizio; Pauselli, Cristina; Frigeri, Alessandro; Forte, Emanuele; Federico, Costanzo

    2014-07-01

    The activation of Late Quaternary faults in the Central Apennines (Italy) could generate earthquakes with magnitude of about 6.5, and the Monte Vettore fault system probably belongs to the same category of seismogenetic faults. Such structure has been defined `silent', because of its geological and geomorphological evidences of past activation, but the absence of historical records in the seismic catalogues to be associated with its activation. The `Piano di Castelluccio' intramountain basin, resulting from the Quaternary activity of normal faults, is characterized by a secondary fault strand highlighted by a NW-SE fault scarp: it has been already studied through palaeoseismological trenches, which highlighted evidences of Quaternary shallow faulting due to strong earthquakes, and through a 2-D ground penetrating radar (GPR) survey, showing the first geophysical signature of faulting for this site. Within the same place, a 3-D GPR volume over a 20 × 20 m area has been collected. The collection of radar echoes in three dimensions allows to map both the vertical and lateral continuity of shallow geometries of the fault zone (Fz), imaging features with high resolution, ranging from few metres to centimetres and therefore imaging also local variations at the microscale. Several geophysical markers of faulting, already highlighted on this site, have been taken as reference to plan the 3-D survey. In this paper, we provide the first 3-D subsurface imaging of an active shallow fault belonging to the Umbria-Marche Apennine highlighting the subsurface fault geometry and the stratigraphic sequence up to a depth of about 5 m. From our data, geophysical faulting signatures are clearly visible in three dimensions: diffraction hyperbolas, truncations of layers, local attenuated zones and varying dip of the layers have been detected within the Fz. The interpretation of the 3-D data set provided qualitative and quantitative geological information in addition to the fault location, like its geometry, boundaries and an estimation of the fault throw.

  2. Stochastic Modeling of Calcium in 3D Geometry

    PubMed Central

    Mazel, Tomáš; Raymond, Rebecca; Raymond-Stintz, Mary; Jett, Stephen; Wilson, Bridget S.

    2009-01-01

    Release of inflammatory mediators by mast cells in type 1 immediate-hypersensitivity allergic reactions relies on antigen-dependent increases in cytosolic calcium. Here, we used a series of electron microscopy images to build a 3D reconstruction representing a slice through a rat tumor mast cell, which then served as a basis for stochastic modeling of inositol-trisphosphate-mediated calcium responses. The stochastic approach was verified by reaction-diffusion modeling within the same geometry. Local proximity of the endoplasmic reticulum to either the plasma membrane or mitochondria is predicted to differentially impact local inositol trisphosphate receptor transport. The explicit consideration of organelle spatial relationships represents an important step toward building a comprehensive, realistic model of cellular calcium dynamics. PMID:19254531

  3. Architecture and growth of normal fault zones in multilayer systems: A 3D field analysis in the South-Eastern Basin, France

    NASA Astrophysics Data System (ADS)

    Roche, V.; Homberg, C.; Rocher, M.

    2012-04-01

    3D field data on mesoscale normal faults were collected to examine the geometries and growth of faults in multilayer systems. Observation and analysis of the fractures include the collection of geometric attributes such as fault dips and fault zone thicknesses, detailed mapping in cross-sections and plan views, and the construction of individual and cumulative displacement profiles. Fault zone growth is consistent with a "coherent model" and is strongly influenced by the multilayer system. In the limestone layers, faults grew in several steps, including opening and frictional sliding on 80° dipping segments. Faulting in clay layers was in the form of 40° dipping faults and sub-horizontal faults, the latter being mostly early features developed under the same extensional regime as normal faults and disturbing the fault architecture. The fault zone thickness increases with the limestone thickness and the presence of sub-horizontal faults in clay beds. Numerous connections occur in clay units. The moderate (?0.08) and low (<0.03) mean displacement gradients in clays and in limestones respectively indicate that the vertical propagation of faults is inhibited in clay layers. Analysis of displacement along fault strike indicates that a 0.08 displacement gradient is associated with the horizontal propagation of fault segments in limestones. According to this value, the fault zones are much longer than expected. It is associated with 'flat topped' displacement profiles along some fault segments and connection between segments to form complex fault zones.

  4. 3D stochastic geophysical inversion for contact surface geometry

    NASA Astrophysics Data System (ADS)

    Lelièvre, Peter; Farquharson, Colin; Bijani, Rodrigo

    2015-04-01

    Geologists' interpretations about the Earth typically involve distinct rock units with contacts (interfaces) between them. As such, 3D geological Earth models typically comprise wireframe contact surfaces of tessellated triangles or other polygonal planar facets. In contrast, standard minimum-structure geophysical inversions are performed on meshes of space-filling cells (typically prisms or tetrahedra) and recover smoothly varying physical property distributions that are inconsistent with typical geological interpretations. There are several approaches through which mesh-based geophysical inversion can help recover models with some of the desired characteristics. However, a more effective strategy is to consider a fundamentally different type of inversion that works directly with models that comprise surfaces representing contacts between rock units. We are researching such an approach, our goal being to perform geophysical forward and inverse modelling directly with 3D geological models of any complexity. Geological and geophysical models should be specified using the same parameterization such that they are, in essence, the same Earth model. We parameterize the wireframe contact surfaces in a 3D model as the coordinates of the nodes (facet vertices). The physical properties of each rock unit in a model remain fixed while the geophysical inversion controls the position of the contact surfaces via the control nodes, perturbing the surfaces as required to fit the geophysical data responses. This is essentially a "geometry inversion", which can be used to recover the unknown geometry of a target body or to investigate the viability of a proposed Earth model. We apply global optimization strategies to solve the inverse problem, including stochastic sampling to obtain statistical information regarding the likelihood of particular features in the model, helping to assess the viability of a proposed model. Jointly inverting multiple types of geophysical data is simple, requiring no additional mathematical coupling measure in the objective function. The use of global optimization methods introduces high computational costs: to provide computationally feasible inversion methods we reduce the dimensionality of the problem by allowing the inversion to control the nodes in a coarse representation of the wireframe model, which is refined before calculating the geophysical responses at each iteration. This strategy also provides a simple and effective way to regularize the inverse problem. We have tested our inversion method on several illustrative synthetics and applied it to a joint inversion of gravity and magnetic survey data collected above an IOCG deposit.

  5. Multifunctional optical nanofiber polarization devices with 3D geometry.

    PubMed

    Chen, Jin-hui; Chen, Ye; Luo, Wei; Kou, Jun-long; Xu, Fei; Lu, Yan-qing

    2014-07-28

    Here a reliable fabrication process enabling the integration of multiple functions in a single rod with one optical nano/microfiber (ONM) was proposed, which represents a further step in the "lab-on-a-rod" technology roadmap. With a unique 3D geometry, the all-fiber in-line devices based on lab-on-a-rod techniques have more freedom and potential for compactness and functionality than conventional fiber devices. With the hybrid polymer-metal-dielectric nanostructure, the coupling between the plasmonic and waveguide modes leads to hybridization of the fundamental mode and polarization-dependent loss. By functionalizing the rod surface with a nanoscale silver film and tuning the coil geometry, a broadband polarizer and single-polarization resonator, respectively, were demonstrated. The polarizer has an extinction ratio of more than 20 dB over a spectral range of 450 nm. The resonator has a Q factor of more than 78,000 with excellent suppression of polarization noise. This type of miniature single-polarization resonator is impossible to realize by conventional fabrication processes and has wide applications in fiber communication, lasing, and especially sensing. PMID:25089409

  6. New High-Resolution 3D Seismic Imagery of Deformation and Fault Architecture Along Newport-Inglewood/Rose Canyon Fault in the Inner California Borderlands

    NASA Astrophysics Data System (ADS)

    Holmes, J. J.; Bormann, J. M.; Driscoll, N. W.; Kent, G.; Harding, A. J.; Wesnousky, S. G.

    2014-12-01

    The tectonic deformation and geomorphology of the Inner California Borderlands (ICB) records the transition from a convergent plate margin to a predominantly dextral strike-slip system. Geodetic measurements of plate boundary deformation onshore indicate that approximately 15%, or 6-8 mm/yr, of the total Pacific-North American relative plate motion is accommodated by faults offshore. The largest near-shore fault system, the Newport-Inglewood/Rose Canyon (NI/RC) fault complex, has a Holocene slip rate estimate of 1.5-2.0 mm/yr, according to onshore trenching, and current models suggest the potential to produce an Mw 7.0+ earthquake. The fault zone extends approximately 120 km, initiating from the south near downtown San Diego and striking northwards with a constraining bend north of Mt. Soledad in La Jolla and continuing northwestward along the continental shelf, eventually stepping onshore at Newport Beach, California. In late 2013, we completed the first high-resolution 3D seismic survey (3.125 m bins) of the NI/RC fault offshore of San Onofre as part of the Southern California Regional Fault Mapping project. We present new constraints on fault geometry and segmentation of the fault system that may play a role in limiting the extent of future earthquake ruptures. In addition, slip rate estimates using piercing points such as offset channels will be explored. These new observations will allow us to investigate recent deformation and strain transfer along the NI/RC fault system.

  7. An Interactive, 3D Fault Editor for VR Environments

    NASA Astrophysics Data System (ADS)

    van Aalsburg, J.; Yikilmaz, M. B.; Kreylos, O.; Kellogg, L. H.; Rundle, J. B.

    2008-12-01

    Digitial Fault Models (DFM) play a vital role in the study of earthquake dynamics, fault-earthquake interactions, and seismicity. DFMs serve as input for finite-element method (FEM) or other earthquake simulations such as Virtual California. Generally, digital fault models are generated by importing a digitized and georeferenced (2D) fault map and/or a hillshade image of the study area into a geographical information system (GIS) application, where individual fault lines are traced by the user. Data assimilation and creation of a DFM, or updating an existing DFM based on new observations, is a tedious and time-consuming process. In order to facilitate the creation process, we are developing an immersive virtual reality (VR) application to visualize and edit fault models. This program is designed to run in immersive environments such as a CAVE (walk-in VR environment), but also works in a wide range of other environments, including desktop systems and GeoWalls. It is being developed at the UC Davis W.M. Keck Center for Active Visualization in the Earth Sciences (KeckCAVES, http://www.keckcaves.org). Our program allows users to create new models or modify existing ones; for instance by repositioning individual fault-segments, by changing the dip angle, or by modifying (or assigning) the value of a property associated with a particular fault segment (i.e. slip rate). With the addition of high resolution Digital Elevation Models (DEM) , georeferenced active tectonic fault maps and earthquake hypocenters, the user can accurately add new segments to an existing model or create a fault model entirely from scratch. Interactively created or modified models can be written to XML files at any time; from there the data may easily be converted into various formats required by the analysis software or simulation. We believe that the ease of interaction provided by VR technology is ideally suited to the problem of creating and editing digital fault models. Our software provides the user with an intuitive environment for visualizing and editing fault model data. This translates not only into less time spent creating fault models, but also enables the researcher to easily generate and maintain any number of models for use in ensemble analysis.

  8. Geometry Refinement of 3D Surfaces Using Kriging Brad Grinstead, Andreas Koschan, and Mongi A. Abidi

    E-print Network

    Abidi, Mongi A.

    , urban 3D models [4, 6, 9] from ground-based systems, 3D models of small objects and indoor mapping [7-world building façade, a laser range scan of the same, the 3D surface generated from the scanned dataGeometry Refinement of 3D Surfaces Using Kriging Brad Grinstead, Andreas Koschan, and Mongi A

  9. The unusual 3D interplay of basement fault reactivation and fault-propagation-fold development: A case study of the Laramide-age Stillwell anticline, west Texas (USA)

    NASA Astrophysics Data System (ADS)

    Surpless, Ben; Hill, Nicola; Beasley, Cara

    2015-10-01

    Subsurface fault geometries have a systematic influence on folds formed above those faults. We use the extraordinarily well-exposed fold geometries of the Laramide-age Stillwell anticline in west Texas (USA) to develop a strain-predictive model of fault-propagation fold formation. The anticline is a 10-km long, NW-trending, NE-vergent, asymmetric fold system with an axis that displays a map-view left-stepping, en echelon pattern. We integrated field observations, geologic and structural data, cross-sections, and 2D kinematic modeling to establish an unusual 3D two-stage model of contractional fold formation, including: 1) reverse reactivation of a pre-existing, NW-striking, SW-dipping, left-stepping, en echelon normal fault system in Paleozoic basement rocks to generate monoclinal flexures in overlying layered Cretaceous carbonate rocks; and 2) the formation of a subsequent flat-ramp fault system that propagated horizontally along a mechanically-weak, clay-rich Cretaceous unit before ramping up at the hinge of the pre-existing monocline system. Strain is focused within the forelimb of the system, in front of the propagating fault tip, and is accommodated by a combination of interlayer slip, flat-ramp faulting, and fracturing proximal to planes of slip. This strain predictive model can be applied to similar, less-well-exposed contractional systems worldwide and provides a new, unusual example of Laramide-age contractional deformation.

  10. High resolution 3D laser scanner measurements of a strike-slip fault quantify its morphological anisotropy at all scales

    E-print Network

    Schmittbuhl, Jean

    High resolution 3D laser scanner measurements of a strike-slip fault quantify its morphological, and J. Schmittbuhl (2006), High resolution 3D laser scanner measurements of a strike-slip fault quantify] The surface roughness of a recently exhumed strike- slip fault plane has been measured by three independent 3D

  11. Dynamic earthquake rupture simulations on nonplanar faults embedded in 3D geometrically complex, heterogeneous elastic solids

    E-print Network

    Dunham, Eric M.

    Dynamic earthquake rupture simulations on nonplanar faults embedded in 3D geometrically complex simulations of earthquake ruptures and the resulting strong ground motion form a crucial component idealization of natural earthquakes. The conditions relating discontinuities in particle velocities across

  12. The COMET method in 3-D hexagonal geometry

    SciTech Connect

    Connolly, K. J.; Rahnema, F.

    2012-07-01

    The hybrid stochastic-deterministic coarse mesh radiation transport (COMET) method developed at Georgia Tech now solves reactor core problems in 3-D hexagonal geometry. In this paper, the method is used to solve three preliminary test problems designed to challenge the method with steep flux gradients, high leakage, and strong asymmetry and heterogeneity in the core. The test problems are composed of blocks taken from a high temperature test reactor benchmark problem. As the method is still in development, these problems and their results are strictly preliminary. Results are compared to whole core Monte Carlo reference solutions in order to verify the method. Relative errors are on the order of 50 pcm in core eigenvalue, and mean relative error in pin fission density calculations is less than 1% in these difficult test cores. The method requires the one-time pre-computation of a response expansion coefficient library, which may be compiled in a comparable amount of time to a single whole core Monte Carlo calculation. After the library has been computed, COMET may solve any number of core configurations on the order of an hour, representing a significant gain in efficiency over other methods for whole core transport calculations. (authors)

  13. Indoor Modelling Benchmark for 3D Geometry Extraction

    NASA Astrophysics Data System (ADS)

    Thomson, C.; Boehm, J.

    2014-06-01

    A combination of faster, cheaper and more accurate hardware, more sophisticated software, and greater industry acceptance have all laid the foundations for an increased desire for accurate 3D parametric models of buildings. Pointclouds are the data source of choice currently with static terrestrial laser scanning the predominant tool for large, dense volume measurement. The current importance of pointclouds as the primary source of real world representation is endorsed by CAD software vendor acquisitions of pointcloud engines in 2011. Both the capture and modelling of indoor environments require great effort in time by the operator (and therefore cost). Automation is seen as a way to aid this by reducing the workload of the user and some commercial packages have appeared that provide automation to some degree. In the data capture phase, advances in indoor mobile mapping systems are speeding up the process, albeit currently with a reduction in accuracy. As a result this paper presents freely accessible pointcloud datasets of two typical areas of a building each captured with two different capture methods and each with an accurate wholly manually created model. These datasets are provided as a benchmark for the research community to gauge the performance and improvements of various techniques for indoor geometry extraction. With this in mind, non-proprietary, interoperable formats are provided such as E57 for the scans and IFC for the reference model. The datasets can be found at: http://indoor-bench.github.io/indoor-bench.

  14. A 3D Immersive Fault Visualizer and Editor

    NASA Astrophysics Data System (ADS)

    Yikilmaz, M. B.; van Aalsburg, J.; Kreylos, O.; Kellogg, L. H.; Rundle, J. B.

    2007-12-01

    Digital fault models are an important resource for the study of earthquake dynamics, fault-earthquake interactions and seismicity. Once digitized these fault models can be used in Finite Element Model (FEM) programs or earthquake simulations such as Virtual California (VC). However, these models are often difficult to create, requiring a substantial amount of time to generate the fault topology and compute the properties of the individual segments. To aid in the construction of such models we have developed an immersive virtual reality (VR) application to visualize and edit fault models. Our program is designed to run in a CAVE (walk-in VR environment), but also works in a wide range of other environments, including desktop systems and GeoWalls. It is being developed at the UC Davis W.M. Keck Center for Active Visualization in the Earth Sciences (KeckCAVES, http://www.keckcaves.org). Immersive VR environments are ideal for visualizing and manipulating three- dimensional data sets. Our program allows users to create new models or modify existing ones; for example by repositioning individual fault-segments, by changing the dip angle, or by modifying (or assigning) the value of a property associated with a particular fault segment (i.e. slip rate). With the addition of high resolution Digital Elevation Models (DEM) the user can accurately add new segments to an existing model or create a fault model entirely from scratch. Interactively created or modified models can be written to XML files at any time; from there the data may easily be converted into various formats required by the analysis software or simulation. We believe that the ease of interaction provided by VR technology is ideally suited to the problem of creating and editing digital fault models. Our software provides the user with an intuitive environment for visualizing and editing fault model data. This translates not only into less time spent creating fault models, but also enables the researcher to easily generate and maintain any number of models for use in ensemble analysis.

  15. 3D Potential Field Inversion for Wireframe Surface Geometry

    E-print Network

    Farquharson, Colin G.

    -based inversion Surface-based inversion (2D) Surface-based inversion (3D) Conclusion Geophysical inversion primer-based inversion (2D) Surface-based inversion (3D) Conclusion Motivation (a) (b) · Geophysical numerical methods-based inversion Surface-based inversion (2D) Surface-based inversion (3D) Conclusion Types of geophysical

  16. Lithological Controls on 3D Fold Geometry in Mechanically Layered Rocks

    NASA Astrophysics Data System (ADS)

    Pearce, M. A.; Jones, R. R.; Rock, G.

    2010-12-01

    Folding and thrusting are key processes in accommodating shortening in evolving orogens. In the outer parts of mountain belts, the combination of tectonism and sedimentation often leads to viable petroleum systems where folds trap migrating hydrocarbons. A key aspect of the success of these traps is the 3D fold geometry, which must prevent up-plunge hydrocarbon escape. Fold shapes in a multilayered system are governed by the fold mechanism, and the rheology of the layers. In sedimentary environments where laterally heterogeneous thicknesses of interbedded carbonates, clastics, and evaporates may be present, predicting the sub-surface geometry of structures is challenging. We present field data combined with satellite and seismic interpretation from the Zagros fold and thrust belt of SE Turkey where Neogene shortening has affected an Ordovician to Miocene aged sedimentary pile comprising shales, sandstones, carbonates and minor evaporites. Miocene carbonates capping the sequence allow 3D fold geometries to be ascertained at surface with a high degree of confidence, whilst the underlying ~1km of shales and mudstones allows folds to develop that depart substantially from standard “text-book” geometries. Beneath these incompetent units a further 1.7km of carbonates and clastics overlie Ordovician shales up to 1.5km thick. In relatively low strain sections asymmetric, angular, kink-like folds form long wavelength structures and thrust faults rarely reach the surface. With increasing strain, the wavelength/amplitude ratio decreases and thrusts cut through the fold limbs. Folds are interpreted to detach above a thick sequence of Ordovician shales. They originate by buckling of the competent units within the two weaker horizons, with initial perturbations probably provided by sedimentary heterogeneities. As the folds amplify, thrusts form in the more competent units above the shale. These then propagate upwards with fold amplification dominated by fault-tip ‘tri-shear’. The mechanical heterogeneity between the near surface shales and overlying carbonate leads to the kink-like geometries seen at surface. In this model, thrust formation is governed by the location of the initial buckle folding. Since the thrusts mostly originate from the top of the Ordovician shales, they form a linked system detaching into the Ordovician so that displacement can transfer from one structure to the next along strike of the orogen. It is the interaction of folds with varying amplitude which is essential in the identification of viable hydrocarbon traps. Incorporation of numerical models which allow ductile folding and brittle failure with these field and remote sensing based studies will inform further exploration in similar areas and allow investigation of the effects of parameters such as lithological thickness on the location and geometry of structures in collisional orogens.

  17. Detection and extraction of fault surfaces in 3D seismic data Israel Cohen1

    E-print Network

    Cohen, Israel

    introduced a multiscale analysis method for the estimation of seismic coherency that is both robust for noiseDetection and extraction of fault surfaces in 3D seismic data Israel Cohen1 , Nicholas Coult2 surfaces in 3D-seismic volumes. The seismic data are transformed into a volume of local

  18. 2D-3D GPR signature of shallow faulting in the Castelluccio di Norcia basin (Central Italy).

    NASA Astrophysics Data System (ADS)

    Ercoli, M.; Pauselli, C.; Frigeri, A.; Forte, E.; Federico, C.

    2012-04-01

    Paleoseismology usually provides seismological data through direct analysis, and uses trenching as the principal investigation technique. Over the last years, the use of non-invasive geophysical methods acquired an important role in paleoseismologic studies. The use of Ground Penetrating Radar (GPR) provided many documented examples of shallow fault zones imaging. In particular, the acquisition of three dimensional GPR data using very dense grids, produces high-resolution data volumes, with high spatial continuity, mandatory for a correct interpretation of the geological features in their actual geometry. We acquired a 3D GPR volume across a fault zone in Central Apennines (Italy). This fault strand shows both geomorphological and trench-derived evidences of Late-Quaternary activity. The GPR volume covers a 20x20 m area providing an high-resolution imaging of the fault zone and its auxilliary structures . Using a free open source software to manage the entire 3D dataset, some horizons and fault features were detected and interpreted. Interpretation was improved using attribute analysis, especially based on amplitude, phase and frequency characteristics. The results of our study provides a detailed 3D geological model of the subsurface extended to more than 4 m below the topographic surface, and a localized area interested by faulting is clearly recognizable. By the use of depth-slices we estimated a width of about 4-2 m, with an average strike of the fault of 170° N. The dip of the W-SW-dipping E-side of the structure was estimated in about 70°, with a total average displacement of about 1 m ± 0.20 m; clinoforms structures, colluvial wedges and sedimentary units showing thickening and rotation close to the fault zone in the hanging-wall were also recognized. Finally some long 2D GPR profiles were acquired and interpreted to extend the observations over a wider area. We successfully detected the continuity of the fault zone towards North, locating also some possible unknown fault strands that can be potentially mapped and added in the future versions of large scale geological maps. Moreover they can be used as additional constrains for seismological modeling. Delineating a characteristic radar signature of specific faults, we believe that GPR data represents a valuable source of quantitative data for paleoseismologic studies, not only to optimise the location for future trenches but also to extend the geological information along and across the fault strike.

  19. Semi-implicit nite volume scheme for image processing in 3D cylindrical geometry

    E-print Network

    Sgallari, Fiorella

    Semi-implicit #12;nite volume scheme for image processing in 3D cylindrical geometry Karol Mikula volume method for image selective smoothing directly in the cylindrical image geometry. Namely, we study semi-implicit 3D cylindrical #12;nite volume scheme for solving Perona-Malik-type nonlinear di#11;usion

  20. SIMULATION OF GEOMETRY AND SHADOW EFFECTS IN 3D ORGANIC POLYMER SOLAR CELLS

    E-print Network

    Kassegne, Samuel Kinde

    levels of Solar panels and new production capacity is driving solar PV prices lower and thereby, bringingSIMULATION OF GEOMETRY AND SHADOW EFFECTS IN 3D ORGANIC POLYMER SOLAR CELLS OF THE THESIS Simulation of Geometry and Shadow Effects in 3D Organic Polymer Solar Cells by Mihir Prakashbhai

  1. Types of Reasoning in 3D Geometry Thinking and Their Relation with Spatial Ability

    ERIC Educational Resources Information Center

    Pittalis, Marios; Christou, Constantinos

    2010-01-01

    The aim of this study is to describe and analyse the structure of 3D geometry thinking by identifying different types of reasoning and to examine their relation with spatial ability. To achieve this goal, two tests were administered to students in grades 5 to 9. The results of the study showed that 3D geometry thinking could be described by four…

  2. Using 3D Computer Graphics Multimedia to Motivate Preservice Teachers' Learning of Geometry and Pedagogy

    ERIC Educational Resources Information Center

    Goodson-Espy, Tracy; Lynch-Davis, Kathleen; Schram, Pamela; Quickenton, Art

    2010-01-01

    This paper describes the genesis and purpose of our geometry methods course, focusing on a geometry-teaching technology we created using NVIDIA[R] Chameleon demonstration. This article presents examples from a sequence of lessons centered about a 3D computer graphics demonstration of the chameleon and its geometry. In addition, we present data…

  3. Super Cooled Large Droplet Analysis of Several Geometries Using LEWICE3D Version 3

    NASA Technical Reports Server (NTRS)

    Bidwell, Colin S.

    2011-01-01

    Super Cooled Large Droplet (SLD) collection efficiency calculations were performed for several geometries using the LEWICE3D Version 3 software. The computations were performed using the NASA Glenn Research Center SLD splashing model which has been incorporated into the LEWICE3D Version 3 software. Comparisons to experiment were made where available. The geometries included two straight wings, a swept 64A008 wing tip, two high lift geometries, and the generic commercial transport DLR-F4 wing body configuration. In general the LEWICE3D Version 3 computations compared well with the 2D LEWICE 3.2.2 results and with experimental data where available.

  4. Displacement transfer from fault-bend to fault-propagation fold geometry: An example from the Himalayan thrust front

    NASA Astrophysics Data System (ADS)

    Qayyum, Mazhar; Spratt, Deborah A.; Dixon, John M.; Lawrence, Robert D.

    2015-08-01

    The leading edge of the ENE-trending Himalayan thrust front in Pakistan exhibits along-strike changes in deformational style, ranging from fault-bend to fault-propagation folds. Although the structural geometry is very gently deformed throughout the Salt Range, it becomes progressively more complex to the east as the leading edge of the emergent Salt Range Thrust becomes blind. Surface geology, seismic reflection, petroleum well, and chronostratigraphic data are synthesized to produce a 3-D kinematic model that reconciles the contrasting structural geometries along this part of the Himalayan thrust front. We propose a model whereby displacement was transferred, across a newly-identified lateral ramp, from a fault-bend fold in the west to fault-propagation folds in the east and comparable shortening was synchronously accommodated by two fundamentally different mechanisms: translation vs. telescoping. However, substantially different shortening distribution patterns within these structurally contrasting segments require a tear fault, which later is reactivated as a thrust fault. The present geometry of this S-shaped displacement transfer zone is a combined result of the NW-SE compression of the lateral culmination wall and associated tear fault, and their subsequent modification due to mobilization of underlying ductile salt.

  5. Constraints on 3D fault and fracture distribution in layered volcanic- volcaniclastic sequences from terrestrial LIDAR datasets: Faroe Islands

    NASA Astrophysics Data System (ADS)

    Raithatha, Bansri; McCaffrey, Kenneth; Walker, Richard; Brown, Richard; Pickering, Giles

    2013-04-01

    Hydrocarbon reservoirs commonly contain an array of fine-scale structures that control fluid flow in the subsurface, such as polyphase fracture networks and small-scale fault zones. These structures are unresolvable using seismic imaging and therefore outcrop-based studies have been used as analogues to characterize fault and fracture networks and assess their impact on fluid flow in the subsurface. To maximize recovery and enhance production, it is essential to understand the geometry, physical properties, and distribution of these structures in 3D. Here we present field data and terrestrial LIDAR-derived 3D, photo-realistic virtual outcrops of fault zones at a range of displacement scales (0.001- 4.5 m) within a volcaniclastic sand- and basaltic lava unit sequence in the Faroe Islands. Detailed field observations were used to constrain the virtual outcrop dataset, and a workflow has been developed to build a discrete fracture network (DFN) models in GOCAD® from these datasets. Model construction involves three main stages: (1) Georeferencing and processing of LIDAR datasets; (2) Structural interpretation to discriminate between faults, fractures, veins, and joint planes using CAD software and RiSCAN Pro; and (3) Building a 3D DFN in GOCAD®. To test the validity of this workflow, we focus here on a 4.5 m displacement strike-slip fault zone that displays a complex polymodal fracture network in the inter-layered basalt-volcaniclastic sequence, which is well-constrained by field study. The DFN models support our initial field-based hypothesis that fault zone geometry varies with increasing displacement through volcaniclastic units. Fracture concentration appears to be greatest in the upper lava unit, decreases into the volcaniclastic sediments, and decreases further into the lower lava unit. This distribution of fractures appears to be related to the width of the fault zone and the amount of fault damage on the outcrop. For instance, the fault zone is thicker in the upper lava unit and therefore fracture concentration is higher, while in the lower lava unit, the fault zone is narrower and thus fracture concentration is also low. Both field observations and the DFN model indicate that the faults and fractures are steeper in the basalts, and shallower in the volcaniclastic sequences, giving a 'stepped' geometry. To assess the nature of sub-seismic fracturing, fracture attributes (connectivity, spacing, length, and orientation) within the model were analysed quantitatively. Continuing work will integrate the detailed field analysis fully, including 1D and 2D fracture transects, structural logging and mapping as well as microstructural characterisation from collected field samples, to understand the complex nature of fracture networks in inter-layered basalt-volcaniclastic sequences. Fracture attributes, such as the shape, length, aspect ratio, curvature and aperture, will be quantified to provide key parameters for fluid flow simulation. Once these attributes have been assessed, experimental data (porosity and permeability) will be incorporated into the DFN model to constrain the fluid flow potential within these inter-layered volcanic sequences.

  6. 3D Dynamic Rupture Simulations Across Interacting Faults: the Mw7.0, 2010, Haiti Earthquake

    NASA Astrophysics Data System (ADS)

    Douilly, R.; Aochi, H.; Calais, E.; Freed, A. M.; Aagaard, B.

    2014-12-01

    The mechanisms controlling rupture propagation between fault segments during an earthquake are key to the hazard posed by fault systems. Rupture initiation on a fault segment sometimes transfers to a larger fault, resulting in a significant event (e.g.i, 2002 M7.9Denali and 2010 M7.1 Darfield earthquakes). In other cases rupture is constrained to the initial segment and does not transfer to nearby faults, resulting in events of moderate magnitude. This is the case of the 1989 M6.9 Loma Prieta and 2010 M7.0 Haiti earthquakes which initiated on reverse faults abutting against a major strike-slip plate boundary fault but did not propagate onto it. Here we investigatethe rupture dynamics of the Haiti earthquake, seeking to understand why rupture propagated across two segments of the Léogâne fault but did not propagate to the adjacenent Enriquillo Plantain Garden Fault, the major 200 km long plate boundary fault cutting through southern Haiti. We use a Finite Element Model to simulate the nucleation and propagation of rupture on the Léogâne fault, varying friction and background stress to determine the parameter set that best explains the observed earthquake sequence. The best-fit simulation is in remarkable agreement with several finite fault inversions and predicts ground displacement in very good agreement with geodetic and geological observations. The two slip patches inferred from finite-fault inversions are explained by the successive rupture of two fault segments oriented favorably with respect to the rupture propagation, while the geometry of the Enriquillo fault did not allow shear stress to reach failure. Although our simulation results replicate well the ground deformation consistent with the geodetic surface observation but convolving the ground motion with the soil amplification from the microzonation study will correctly account for the heterogeneity of the PGA throughout the rupture area.

  7. Effective friction law for smallscale fault heterogeneity in 3D dynamic rupture

    E-print Network

    Nicolas, Chamot-Rooke

    Effective friction law for smallscale fault heterogeneity in 3D dynamic rupture S. Latour,1 M friction, we numerically construct effective friction laws that integrate the effects of smallscale, the static friction heterogeneities and the friction law. We first define a periodic smallscale heterogeneous

  8. Changes to 3D muscle fascicle geometry during contraction Manku Rana, 2

    E-print Network

    Hamarneh, Ghassan

    Changes to 3D muscle fascicle geometry during contraction 1 Manku Rana, 2 Ghassan Hamarneh and 2, Burnaby, BC, Canada email: manku.rana@usc.edu INTRODUCTION Muscle is a three dimensional (3D) entity with varying shape across the length of the muscle and changes shape during contraction. Changes in muscle

  9. Geometry and earthquake potential of the shoreline fault, central California

    USGS Publications Warehouse

    Hardebeck, Jeanne L.

    2013-01-01

    The Shoreline fault is a vertical strike?slip fault running along the coastline near San Luis Obispo, California. Much is unknown about the Shoreline fault, including its slip rate and the details of its geometry. Here, I study the geometry of the Shoreline fault at seismogenic depth, as well as the adjacent section of the offshore Hosgri fault, using seismicity relocations and earthquake focal mechanisms. The Optimal Anisotropic Dynamic Clustering (OADC) algorithm (Ouillon et al., 2008) is used to objectively identify the simplest planar fault geometry that fits all of the earthquakes to within their location uncertainty. The OADC results show that the Shoreline fault is a single continuous structure that connects to the Hosgri fault. Discontinuities smaller than about 1 km may be undetected, but would be too small to be barriers to earthquake rupture. The Hosgri fault dips steeply to the east, while the Shoreline fault is essentially vertical, so the Hosgri fault dips towards and under the Shoreline fault as the two faults approach their intersection. The focal mechanisms generally agree with pure right?lateral strike?slip on the OADC planes, but suggest a non?planar Hosgri fault or another structure underlying the northern Shoreline fault. The Shoreline fault most likely transfers strike?slip motion between the Hosgri fault and other faults of the Pacific–North America plate boundary system to the east. A hypothetical earthquake rupturing the entire known length of the Shoreline fault would have a moment magnitude of 6.4–6.8. A hypothetical earthquake rupturing the Shoreline fault and the section of the Hosgri fault north of the Hosgri–Shoreline junction would have a moment magnitude of 7.2–7.5.

  10. 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 basement appears in places to have acted as an extensional slip surface. We interpret the complex pattern of faulting and internal block deformation as the results of several phases of faulting, coupled with internal deformation and some late gravitational collapse, all components of some of the various models that have been applied to this margin.

  11. Listric versus planar normal fault geometry: an example from the Eisenstadt-Sopron Basin (E Austria)

    NASA Astrophysics Data System (ADS)

    Spahi?, Darko; Exner, Ulrike; Behm, Michael; Grasemann, Bernhard; Haring, Alexander; Pretsch, Herbert

    2011-10-01

    In a gravel pit at the eastern margin of the Eisenstadt-Sopron Basin, a satellite of Vienna Basin (Austria), Neogene sediments are exposed in the hanging wall of a major normal fault. The anticlinal structure and associated conjugated secondary normal faults were previously interpreted as a rollover anticline above a listric normal fault. The spatial orientation and distribution of sedimentary horizons and crosscutting faults were mapped in detail on a laser scan of the outcrop wall. Subsequently, in order to assess the 3D distribution and geometry of this fault system, a series of parallel ground penetrating radar (GPR) profiles were recorded behind the outcrop wall. Both outcrop and GPR data were compiled in a 3D structural model, providing the basis for a kinematic reconstruction of the fault plane using balanced cross-section techniques. However, the kinematic reconstruction results in a geologically meaningless normal fault cutting down- and up-section. Additionally, no evidence for a weak layer serving as ductile detachment horizon (i.e. salt or clay horizon) can be identified in stratigraphic profiles. Instead, the observed deflection of stratigraphic horizons may be caused by a displacement gradient along a planar master fault, with a maximum displacement in the fault centre, decreasing towards the fault tips. Accordingly, the observed deflection of markers in the hanging wall—and in a nearby location in the footwall of the normal fault—is interpreted as large-scale fault drag along a planar fault that records a displacement gradient, instead of a rollover anticline related to a listric fault.

  12. Verification of internal flow analyses in complex 3-D geometries

    NASA Astrophysics Data System (ADS)

    Choi, S. K.; Buggeln, R. C.

    1992-11-01

    Analysis of internal flow in advanced rocket propulsion systems is complicated by hardware geometry, high Reynolds numbers, rotation, high frequency phenomena, and near incompressibility. Typical of such a problem is the Space Shuttle Main Engine (SSME) hot gas manifold (HGM). Previous analyses of flow in the SSME HGM have been compared to air flow data and found to be inaccurate with respect to system losses, outer wall static pressures, and transfer duct environments. Such discrepancies could arise from flow measurement methodology, low order algorithms, turbulence modeling, and/or inadequate grid resolution. The objective of this work is to compare internal flow computational analyses to LDV flow measurements for the MSFC HGM pilot model configuration using two grids of different node density in the near wall region. Grids were generated with the EAGLE grid generator and calculations were made with the SRA MINT code. The calculated results were compared with HGM experimental data obtained in the MSFC water flow facility.

  13. Visual and haptic geometry of 3D shape discrimination.

    PubMed

    Phillips, Flip; O'Donnell, Emerson; Kernis, Noah

    2015-09-01

    There are countless candidate 'features' useful for the perceptual discrimination of three-dimensional shape. Human vision and touch use both modality-specific and cross-modal information to accomplish this task. For example, only vision can make diagnostic use of shading, color and optical texture while only touch can detect temperature, vibratory and other proprioceptive information such as joint angle. Some characteristics such as the physical texture of an object provide both visual appearance and tactile roughness information. When attempting to determine the 3D shape of an object its structural geometric information underlies most if not all of the useful features used by both vision and touch, individually or in concert. It is an open question as to what specific geometric information is essential or useful when performing discrimination tasks that involve vision, touch or their interaction. This research investigates the use of statistical differential geometric information while performing detection and discrimination tasks, both within and across perceptual modalities. We use eye- and hand-tracking to determine which parts of an object our subjects explore while making shape discrimination and differentiation decisions. We correlate these high-exploration regions with the objects' underlying differential geometric structure. We find that object regions with high curvature contrast are useful across both modalities as they define 'sharp' linear structures. Similarly, areas with high relative curvedness provide useful point landmarks. We further show that some geometric structures are more useful within a particular modality than another. As a result the worst-performing modality limits cross-modal use of this information but simultaneous presentation is facilitative. Finally, the statistical distribution of differential geometric structures serves to define diagnostic 'features' available to either touch or vision. The relative occurrence of features and their magnitude determine their usefulness within and across modalities. Meeting abstract presented at VSS 2015. PMID:26326554

  14. 3-D Ground Motion Modeling for M7 Dynamic Rupture Earthquake Scenarios on the Wasatch Fault, Utah

    NASA Astrophysics Data System (ADS)

    Roten, D.; Olsen, K. B.; Pechmann, J. C.; Cruz-Atienza, V.; Magistrale, H.

    2008-12-01

    The Salt Lake City (SLC) segment of the Wasatch fault (WF) forms the eastern edge of the Salt Lake Valley, populated by 1 million people and underlain by alluvial sediments. The WF is capable of producing M7 earthquakes and represents a serious hazard to SLC, Utah. There is a large uncertainty associated with the ground motions expected from such events, due in part to the lack of strong motion records from large normal-faulting earthquakes, and to possible amplification effects from basin focusing and source directivity. We address these uncertainties by performing a series of rupture simulations on the WF using realistic sources, a sophisticated geophysical model of the Salt Lake Basin (SLB) and a complex 3-D model of the SLC segment of the WF. We use the newly developed Wasatch front community velocity model (WFCVM) which consists of detailed site response units and shallow shear wave data atop rule-based representations of basins along the Wasatch front, all embedded in a 3-D crust derived from seismic tomography. The WFCVM is validated by simulating three recorded, local M_w 3.3--3.7 earthquakes. The simulated ground motions reproduce the amplitude and duration of the observations at most sites reasonably well from 0.5--1.0 Hz, suggesting that the WFCVM is sufficiently accurate to be used for ground motion estimation up to 1 Hz. The M7 earthquake scenarios make use of a detailed 3-D model geometry of the SLC segment of the WF that we developed based on geological observations. To obtain a suite of realistic source representations for M7 WF simulations we perform spontaneous-rupture simulations on a planar, 43 km by 23 km fault with the staggered-grid split-node finite difference method. The stress drop and friction parameters were based on probabilistic spectral laws derived from earthquake seismic records. The resulting M_w7 rupture scenarios have maximum surface slip ranging from 2.5 to 3.2 meters. The slip rate histories from the spontaneous rupture scenarios are projected onto the irregular dipping geometry of the SLC fault segment and used to simulate wave propagation in the SLB using a 4th-order, staggered-grid visco-elastic finite difference method. We assess the importance of amplification effects caused by the velocity contrast between the hanging-wall sedimentary basin and the stiffer footwall rocks, quantify the sensitivity of the simulated ground motion to the rupture propagation direction and examine the variability of the simulated peak ground velocities for several rupture scenarios.

  15. Discovery of previously unrecognised local faults in London, UK, using detailed 3D geological modelling

    NASA Astrophysics Data System (ADS)

    Aldiss, Don; Haslam, Richard

    2013-04-01

    In parts of London, faulting introduces lateral heterogeneity to the local ground conditions, especially where construction works intercept the Palaeogene Lambeth Group. This brings difficulties to the compilation of a ground model that is fully consistent with the ground investigation data, and so to the design and construction of engineering works. However, because bedrock in the London area is rather uniform at outcrop, and is widely covered by Quaternary deposits, few faults are shown on the geological maps of the area. This paper discusses a successful resolution of this problem at a site in east central London, where tunnels for a new underground railway station are planned. A 3D geological model was used to provide an understanding of the local geological structure, in faulted Lambeth Group strata, that had not been possible by other commonly-used methods. This model includes seven previously unrecognised faults, with downthrows ranging from about 1 m to about 12 m. The model was constructed in the GSI3D geological modelling software using about 145 borehole records, including many legacy records, in an area of 850 m by 500 m. The basis of a GSI3D 3D geological model is a network of 2D cross-sections drawn by a geologist, generally connecting borehole positions (where the borehole records define the level of the geological units that are present), and outcrop and subcrop lines for those units (where shown by a geological map). When the lines tracing the base of each geological unit within the intersecting cross-sections are complete and mutually consistent, the software is used to generate TIN surfaces between those lines, so creating a 3D geological model. Even where a geological model is constructed as if no faults were present, changes in apparent dip between two data points within a single cross-section can indicate that a fault is present in that segment of the cross-section. If displacements of similar size with the same polarity are found in a series of adjacent cross-sections, the presence of a fault can be substantiated. If it is assumed that the fault is planar and vertical, then the pairs of constraining data points in each cross-section form a two-dimensional envelope within which the surface trace of the fault must lie. Generally, the broader the area of the model, the longer the envelope defined by the pairs of boreholes is, resulting in better constraint of the fault zone width and azimuth. Repetition or omission of the local stratigraphy in the constraining boreholes can demonstrate reverse or normal dip-slip motion. Even if this is not possible, borehole intercepts at the base of the youngest bedrock unit or at the top of the oldest bedrock unit can constrain the minimum angle of dip of the fault plane. Assessment of the maximum angle of dip requires intrusive investigation. This work is distributed under the Creative Commons Attribution 3.0 Unported License together with an NERC copyright. This license does not conflict with the regulations of the Crown Copyright.

  16. Fault geometries and location in sedimentary cover during basement-controlled deformation: An experimental investigation

    SciTech Connect

    Vendeville, B. )

    1988-08-01

    Recent regional seismic and field investigations in the North Sea and the Gulf of Suez have shown that extension is partly controlled by reactivation of inherited basement structures and their upward propagation into the overlying sedimentary rocks. Basement control is expected to induce complex fault patterns into the sedimentary cover, especially if it includes weak stratigraphic horizons such as evaporites, marls, or shales. Relations between basement and cover fault geometries have been studied using scaled analog experiments and synthetic seismograms, which were compared with field and seismic data. Experiments were conducted for different dips of the basement fault and for a variety of rheological behaviors of the sedimentary sequence, ranging from purely ductile to entirely brittle. Ductile rocks were modeled using perfectly fluid silicon putty; dry sand simulated brittle layers. Experimental results show that both reverse and normal faults may occur, and that fault location, orientation, and development strongly depend on the rheology of the sedimentary cover. Basement-induced extension of a brittle cover induces transient high-angle reverse faults and late normal faults which both root into the basement fault at depth. Models with a ductile layer at the basement-cover interface show a permanent reverse fault above the basement fault, a basinward tilted block, and a rear graben structure located in the uplifted block. The geometry of transfer zones has also been investigated using 3-D models of interaction between tear faults and basement faults. Models show the development of arcuate structures and point out the influence of lateral boundary effects on the orientation of shallow normal and reverse faults.

  17. 3-D ground motion modeling for M7 dynamic rupture earthquake scenarios on the Wasatch fault, Utah

    NASA Astrophysics Data System (ADS)

    Roten, D.; Olsen, K. B.; Cruz Atienza, V. M.; Pechmann, J. C.; Magistrale, H. W.

    2009-12-01

    The Salt Lake City segment of the Wasatch fault (WFSLC), located on the eastern edge of the Salt Lake Basin (SLB), is capable of producing M7 earthquakes and represents a serious seismic hazard to Salt Lake City, Utah. We simulate a series of rupture scenarios on the WFSLC to quantify the ground motion expected from such M7 events and to assess the importance of amplification effects from basin focusing and source directivity. We use the newly revised Wasatch Front community velocity model for our simulations, which is tested by simulating records of three local Mw 3.3-3.7 earthquakes in the frequency band 0.5 to 1.0 Hz. The M7 earthquake scenarios make use of a detailed 3-D model geometry of the WFSLC that we developed based on geological observations. To obtain a suite of realistic source representations for M7 WFSLC simulations we perform spontaneous-rupture simulations on a planar 43 km by 23 km fault with the staggered-grid split-node finite-difference (FD) method. We estimate the initial distribution of shear stress using models that assume depth-dependent normal stress for a dipping, normal fault as well as simpler models which use constant (depth-independent) normal stress. The slip rate histories from the spontaneous rupture scenarios are projected onto the irregular dipping geometry of the WFSLC and used to simulate 0-1 Hz wave propagation in the SLB area using a 4th-order, staggered-grid visco-elastic FD method. We find that peak ground velocities tend to be larger on the low-velocity sediments on the hanging wall side of the fault than on outcropping rock on the footwall side, confirming results of previous studies on normal faulting earthquakes. The simulated ground motions reveal strong along-strike directivity effects for ruptures nucleating towards the ends of the WFSLC. The 0-1 Hz FD simulations are combined with local scattering operators to obtain broadband (0-10 Hz) synthetics and maps of average peak ground motions. Finally we use broadband synthetics at shallow depth, modified to exclude effects of the free surface, as input to compute fully nonlinear 1-D SH ground motion along two profiles across the SLB. Nonlinear parameters of the SLB sediments are constrained from empirical relationships, which were adapted to match recent laboratory results for local Bonneville clay samples. The results of these combined 3-D linear, broadband and 1-D nonlinear simulations will help to quantify the combined effects of source directivity, basin amplification and nonlinear soil behaviour during future M7 earthquakes on the WFSLC.

  18. KENO3D Visualization Tool for KENO V.a and KENO-VI Geometry Models

    SciTech Connect

    Horwedel, J.E.; Bowman, S.M.

    2000-06-01

    Criticality safety analyses often require detailed modeling of complex geometries. Effective visualization tools can enhance checking the accuracy of these models. This report describes the KENO3D visualization tool developed at the Oak Ridge National Laboratory (ORNL) to provide visualization of KENO V.a and KENO-VI criticality safety models. The development of KENO3D is part of the current efforts to enhance the SCALE (Standardized Computer Analyses for Licensing Evaluations) computer software system.

  19. Preliminary simulation of a M6.5 earthquake on the Seattle Fault using 3D finite-difference modeling

    USGS Publications Warehouse

    Stephenson, William J.; Frankel, Arthur D.

    2000-01-01

    A three-dimensional finite-difference simulation of a moderate-sized (M 6.5) thrust-faulting earthquake on the Seattle fault demonstrates the effects of the Seattle Basin on strong ground motion in the Puget lowland. The model area includes the cities of Seattle, Bremerton and Bellevue. We use a recently developed detailed 3D-velocity model of the Seattle Basin in these simulations. The model extended to 20-km depth and assumed rupture on a finite fault with random slip distribution. Preliminary results from simulations of frequencies 0.5 Hz and lower suggest amplification can occur at the surface of the Seattle Basin by the trapping of energy in the Quaternary sediments. Surface waves generated within the basin appear to contribute to amplification throughout the modeled region. Several factors apparently contribute to large ground motions in downtown Seattle: (1) radiation pattern and directivity from the rupture; (2) amplification and energy trapping within the Quaternary sediments; and (3) basin geometry and variation in depth of both Quaternary and Tertiary sediments

  20. Dynamic earthquake rupture simulation on nonplanar faults embedded in 3D geometrically complex, heterogeneous Earth models

    NASA Astrophysics Data System (ADS)

    Duru, K.; Dunham, E. M.; Bydlon, S. A.; Radhakrishnan, H.

    2014-12-01

    Dynamic propagation of shear ruptures on a frictional interface is a useful idealization of a natural earthquake.The conditions relating slip rate and fault shear strength are often expressed as nonlinear friction laws.The corresponding initial boundary value problems are both numerically and computationally challenging.In addition, seismic waves generated by earthquake ruptures must be propagated, far away from fault zones, to seismic stations and remote areas.Therefore, reliable and efficient numerical simulations require both provably stable and high order accurate numerical methods.We present a numerical method for:a) enforcing nonlinear friction laws, in a consistent and provably stable manner, suitable for efficient explicit time integration;b) dynamic propagation of earthquake ruptures along rough faults; c) accurate propagation of seismic waves in heterogeneous media with free surface topography.We solve the first order form of the 3D elastic wave equation on a boundary-conforming curvilinear mesh, in terms of particle velocities and stresses that are collocated in space and time, using summation-by-parts finite differences in space. The finite difference stencils are 6th order accurate in the interior and 3rd order accurate close to the boundaries. Boundary and interface conditions are imposed weakly using penalties. By deriving semi-discrete energy estimates analogous to the continuous energy estimates we prove numerical stability. Time stepping is performed with a 4th order accurate explicit low storage Runge-Kutta scheme. We have performed extensive numerical experiments using a slip-weakening friction law on non-planar faults, including recent SCEC benchmark problems. We also show simulations on fractal faults revealing the complexity of rupture dynamics on rough faults. We are presently extending our method to rate-and-state friction laws and off-fault plasticity.

  1. Accurate 3D reconstruction of complex blood vessel geometries from intravascular ultrasound

    E-print Network

    Subramanian, Kalpathi R.

    Accurate 3D reconstruction of complex blood vessel geometries from intravascular ultrasound images from 2D intravascular ultrasound (IVUS) images. Biplane x-ray ¯uoroscopy is used to image the ultrasound catheter tip at a few key points along its path as the catheter is pulled through the blood vessel

  2. Diminished Reality using Appearance and 3D Geometry of Internet Photo Collections

    E-print Network

    Fah, Cheong Loong

    - formation Systems--Augmented Reality; I.4.8 [Image Processing and Computer Vision]: Scene Analysis INTRODUCTION While augmented reality (AR) enhances users' perception of real- ity with contextDiminished Reality using Appearance and 3D Geometry of Internet Photo Collections Zhuwen Li1 Yuxi

  3. AN APPROACH FOR INTERSUBJECT ANALYSIS OF 3D BRAIN IMAGES BASED ON CONFORMAL GEOMETRY

    E-print Network

    Hua, Jing

    AN APPROACH FOR INTERSUBJECT ANALYSIS OF 3D BRAIN IMAGES BASED ON CONFORMAL GEOMETRY Guangyu Zou Emission Tomography (PET) and Diffusion Tensor Imaging (DTI) have accelerated brain research in many aspects. In order to better understand the synergy of the many processes involved in normal brain function

  4. Dynamic earthquake rupture simulations on nonplanar faults embedded in 3D geometrically complex, heterogeneous elastic solids

    NASA Astrophysics Data System (ADS)

    Duru, Kenneth; Dunham, Eric M.

    2016-01-01

    Dynamic propagation of shear ruptures on a frictional interface in an elastic solid is a useful idealization of natural earthquakes. The conditions relating discontinuities in particle velocities across fault zones and tractions acting on the fault are often expressed as nonlinear friction laws. The corresponding initial boundary value problems are both numerically and computationally challenging. In addition, seismic waves generated by earthquake ruptures must be propagated for many wavelengths away from the fault. Therefore, reliable and efficient numerical simulations require both provably stable and high order accurate numerical methods. We present a high order accurate finite difference method for: a) enforcing nonlinear friction laws, in a consistent and provably stable manner, suitable for efficient explicit time integration; b) dynamic propagation of earthquake ruptures along nonplanar faults; and c) accurate propagation of seismic waves in heterogeneous media with free surface topography. We solve the first order form of the 3D elastic wave equation on a boundary-conforming curvilinear mesh, in terms of particle velocities and stresses that are collocated in space and time, using summation-by-parts (SBP) finite difference operators in space. Boundary and interface conditions are imposed weakly using penalties. By deriving semi-discrete energy estimates analogous to the continuous energy estimates we prove numerical stability. The finite difference stencils used in this paper are sixth order accurate in the interior and third order accurate close to the boundaries. However, the method is applicable to any spatial operator with a diagonal norm satisfying the SBP property. Time stepping is performed with a 4th order accurate explicit low storage Runge-Kutta scheme, thus yielding a globally fourth order accurate method in both space and time. We show numerical simulations on band limited self-similar fractal faults revealing the complexity of rupture dynamics on rough faults.

  5. Fault geometries in basement-induced wrench faulting under different initial stress states

    NASA Astrophysics Data System (ADS)

    Naylor, M. A.; Mandl, G.; Supesteijn, C. H. K.

    Scaled sandbox experiments were used to generate models for relative ages, dip, strike and three-dimensional shape of faults in basement-controlled wrench faulting. The basic fault sequence runs from early en échelon Riedel shears and splay faults through 'lower-angle' shears to P shears. The Riedel shears are concave upwards and define a tulip structure in cross-section. In three dimensions, each Riedel shear has a helicoidal form. The sequence of faults and three-dimensional geometry are rationalized in terms of the prevailing stress field and Coulomb-Mohr theory of shear failure. The stress state in the sedimentary overburden before wrenching begins has a substantial influence on the fault geometries and on the final complexity of the fault zone. With the maximum compressive stress (? 1) initially parallel to the basement fault (transtension), Riedel shears are only slightly en échelon, sub-parallel to the basement fault, steeply dipping with a reduced helicoidal aspect. Conversely, with ? 1 initially perpendicular to the basement fault (transpression), Riedel shears are strongly oblique to the basement fault strike, have lower dips and an exaggerated helicoidal form; the final fault zone is both wide and complex. We find good agreement between the models and both mechanical theory and natural examples of wrench faulting.

  6. A Revised Interpretation of 3D Seismic Data, Hawthorne Army Depot, Nevada: FaultedBasin Reflections or Sill Intrusions?

    E-print Network

    A Revised Interpretation of 3D Seismic Data, Hawthorne Army Depot, Nevada: FaultedBasin of the Great Basin containing numerous extensional geothermal systems (Surpless, 2008; Oldow, 2003). A 3d. The Walker Lane province of the Great Basin is an area of the Western United States dominated by NNW

  7. Graph-based segmentation for RGB-D data using 3-D geometry enhanced superpixels.

    PubMed

    Yang, Jingyu; Gan, Ziqiao; Li, Kun; Hou, Chunping

    2015-05-01

    With the advances of depth sensing technologies, color image plus depth information (referred to as RGB-D data hereafter) is more and more popular for comprehensive description of 3-D scenes. This paper proposes a two-stage segmentation method for RGB-D data: 1) oversegmentation by 3-D geometry enhanced superpixels and 2) graph-based merging with label cost from superpixels. In the oversegmentation stage, 3-D geometrical information is reconstructed from the depth map. Then, a K-means-like clustering method is applied to the RGB-D data for oversegmentation using an 8-D distance metric constructed from both color and 3-D geometrical information. In the merging stage, treating each superpixel as a node, a graph-based model is set up to relabel the superpixels into semantically-coherent segments. In the graph-based model, RGB-D proximity, texture similarity, and boundary continuity are incorporated into the smoothness term to exploit the correlations of neighboring superpixels. To obtain a compact labeling, the label term is designed to penalize labels linking to similar superpixels that likely belong to the same object. Both the proposed 3-D geometry enhanced superpixel clustering method and the graph-based merging method from superpixels are evaluated by qualitative and quantitative results. By the fusion of color and depth information, the proposed method achieves superior segmentation performance over several state-of-the-art algorithms. PMID:25095278

  8. Late cenozoic displacement transfer in the eastern Sylvania Mountain fault system and Lida Valley pull-apart basin, southwestern Nevada, based on 3D gravity depth inversion and forward models

    NASA Astrophysics Data System (ADS)

    Dunn, Sarah Beth

    The Sylvania Mountain fault system transfers displacement from the Eastern California shear zone to the Walker Lane as it stretches from the Furnace Creek-Fish Lake Valley fault in southwestern Nevada. Strands of the structure bound the Lida Valley pull-apart basin which, based on gravity analysis, is internally dissected by a system of faults. The subsurface geometry was determined from our gravity survey with data inverted in 3D. Geologic cross-sections were used to forward model the gravity. Mapped faults and inferred structures were combined to construct the subsurface geometry and evaluate a fault displacement budget. By conserving fault slip, the restoration of the pre-Neogene basement to a reference datum indicates a cumulative vertical displacement of 2.3 to 2.5 km since onset of extension. Vertical displacements were used to compute the horizontal component of extension, ranging from 1.3 to 1.4 km.

  9. Experiments with Uas Imagery for Automatic Modeling of Power Line 3d Geometry

    NASA Astrophysics Data System (ADS)

    Jó?ków, G.; Vander Jagt, B.; Toth, C.

    2015-08-01

    The ideal mapping technology for transmission line inspection is the airborne LiDAR executed from helicopter platforms. It allows for full 3D geometry extraction in highly automated manner. Large scale aerial images can be also used for this purpose, however, automation is possible only for finding transmission line positions (2D geometry), and the sag needs to be estimated manually. For longer lines, these techniques are less expensive than ground surveys, yet they are still expensive. UAS technology has the potential to reduce these costs, especially if using inexpensive platforms with consumer grade cameras. This study investigates the potential of using high resolution UAS imagery for automatic modeling of transmission line 3D geometry. The key point of this experiment was to employ dense matching algorithms to appropriately acquired UAS images to have points created also on wires. This allowed to model the 3D geometry of transmission lines similarly to LiDAR acquired point clouds. Results showed that the transmission line modeling is possible with a high internal accuracy for both, horizontal and vertical directions, even when wires were represented by a partial (sparse) point cloud.

  10. Reliable and Fault-Tolerant Software-Defined Network Operations Scheme for Remote 3D Printing

    NASA Astrophysics Data System (ADS)

    Kim, Dongkyun; Gil, Joon-Min

    2015-03-01

    The recent wide expansion of applicable three-dimensional (3D) printing and software-defined networking (SDN) technologies has led to a great deal of attention being focused on efficient remote control of manufacturing processes. SDN is a renowned paradigm for network softwarization, which has helped facilitate remote manufacturing in association with high network performance, since SDN is designed to control network paths and traffic flows, guaranteeing improved quality of services by obtaining network requests from end-applications on demand through the separated SDN controller or control plane. However, current SDN approaches are generally focused on the controls and automation of the networks, which indicates that there is a lack of management plane development designed for a reliable and fault-tolerant SDN environment. Therefore, in addition to the inherent advantage of SDN, this paper proposes a new software-defined network operations center (SD-NOC) architecture to strengthen the reliability and fault-tolerance of SDN in terms of network operations and management in particular. The cooperation and orchestration between SDN and SD-NOC are also introduced for the SDN failover processes based on four principal SDN breakdown scenarios derived from the failures of the controller, SDN nodes, and connected links. The abovementioned SDN troubles significantly reduce the network reachability to remote devices (e.g., 3D printers, super high-definition cameras, etc.) and the reliability of relevant control processes. Our performance consideration and analysis results show that the proposed scheme can shrink operations and management overheads of SDN, which leads to the enhancement of responsiveness and reliability of SDN for remote 3D printing and control processes.

  11. Effect of geometry on drug release from 3D printed tablets.

    PubMed

    Goyanes, Alvaro; Robles Martinez, Pamela; Buanz, Asma; Basit, Abdul W; Gaisford, Simon

    2015-10-30

    The aim of this work was to explore the feasibility of combining hot melt extrusion (HME) with 3D printing (3DP) technology, with a view to producing different shaped tablets which would be otherwise difficult to produce using traditional methods. A filament extruder was used to obtain approx. 4% paracetamol loaded filaments of polyvinyl alcohol with characteristics suitable for use in fused-deposition modelling 3DP. Five different tablet geometries were successfully 3D-printed-cube, pyramid, cylinder, sphere and torus. The printing process did not affect the stability of the drug. Drug release from the tablets was not dependent on the surface area but instead on surface area to volume ratio, indicating the influence that geometrical shape has on drug release. An erosion-mediated process controlled drug release. This work has demonstrated the potential of 3DP to manufacture tablet shapes of different geometries, many of which would be challenging to manufacture by powder compaction. PMID:25934428

  12. 3D Bioprinting of complex channels-Effects of material, orientation, geometry, and cell embedding.

    PubMed

    Wüst, Silke; Müller, Ralph; Hofmann, Sandra

    2015-08-01

    Creating filled or hollow channels within 3D tissues has become increasingly important in tissue engineering. Channels can serve as vasculature enhancing medium perfusion or as conduits for nerve regeneration. The 3D biofabrication seems to be a promising method to generate these structures within 3D constructs layer-by-layer. In this study, geometry and interface of bioprinted channels were investigated with micro-computed tomography and fluorescent imaging. In filament printing, size and shape of printed channels are influenced by their orientation, which was analyzed by printing horizontally and vertically aligned channels, and by the ink, which was evaluated by comparing channels printed with an alginate-gelatin hydrogel or with an emulsion. The influence of geometry and cell-embedding in the hydrogel on feature size and shape was investigated by printing more complex channels. The generation of hollow channels, induced through leaching of a support phase, was monitored over time. Horizontally aligned channels provided 16× smaller cross-sectional areas than channels in vertical orientation. The smallest feature size of hydrogel filaments was twice as large compared to emulsion filaments. Feature size and shape depended on the geometry but did not alter when living cells were embedded. With that knowledge, channels can be consciously tailored to the particular needs. PMID:25524726

  13. The 3-D world modeling with updating capability based on combinatorial geometry

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

    A 3-D world modeling technique using range data is discribed. Range data quantify the distances from the sensor focal plane to the object surface, i.e., the 3-D coordinates of discrete points on the object surface are known. The approach proposed herein for 3-D world modeling is based on the Combinatorial Geometry (CG) method which is widely used in Monte Carlo particle transport calculations. First, each measured point on the object surface is surrounded by a small sphere with a radius determined by the range to that point. Then, the 3-D shapes of the visible surfaces are obtained by taking the (Boolean) union of all the spheres. The result is an unambiguous representation of the object's boundary surfaces. The pre-learned partial knowledge of the environment can be also represented using the CG Method with a relatively small amount of data. Using the CG type of representation, distances in desired directions to boundary surfaces of various objects are efficiently calculated. This feature is particularly useful for continuously verifying the world model against the data provided by a range finder, and for integrating range data from successive locations of the robot during motion. The efficiency of the proposed approach is illustrated by simulations of a spherical robot in a 3-D room in the presence of moving obstacles and inadequate prelearned partial knowledge of the environment.

  14. 3D Image Tour of the Hayward Fault in the East Bay, San Francisco Bay Region, California

    NASA Astrophysics Data System (ADS)

    Stoffer, P.

    2007-12-01

    A 3D image tour of the Hayward Fault begins at its northern land-based terminus at Point Pinole from where it continues northward under the waters of San Pablo Bay. From Point Pinole, the Hayward Fault extends southward for about 90 kilometers through the urbanized landscape of the East Bay region, passing through the cities of Richmond, Berkeley, Oakland, San Leandro, Hayward, Fremont, and other communities. At its southern end, the fault forms a series of oblique reverse faults, but at depth it connects with the Calaveras Fault as a through-going structure along the western foothills of the Diablo Range east of the greater San Jose area. This presentation focuses on access to the Hayward Fault in public places where features impacted by active fault creep can be viewed. Features include offset curbs, fractures in sidewalks, parking areas, buildings, and damage to other infrastructure in the active fault zone. Additional images highlight landscape features and historic landmarks along the fault, including those that were impacted by the 1868 Hayward earthquake, and those that were or were engineered both with and without consideration of the location of the fault. Earthquake data and geologic interpretations of the subsurface along the fault zone are also presented. This presentation, and an associated website, is for educational audiences with the intent of promoting public awareness and earthquake preparedness. This work is part of the ongoing outreach and public education efforts by the U.S. Geological Survey in cooperation with the 1868 Hayward Earthquake Alliance in anticipation of the 140th anniversary of the great earthquake. The use of 3D imagery enhances the educational value of the presentation and provides a unique perspective on the subject matter. Red-and-cyan 3D viewing glasses will be available at the presentation.

  15. IM3D: A parallel Monte Carlo code for efficient simulations of primary radiation displacements and damage in 3D geometry.

    PubMed

    Li, Yong Gang; Yang, Yang; Short, Michael P; Ding, Ze Jun; Zeng, Zhi; Li, Ju

    2015-01-01

    SRIM-like codes have limitations in describing general 3D geometries, for modeling radiation displacements and damage in nanostructured materials. A universal, computationally efficient and massively parallel 3D Monte Carlo code, IM3D, has been developed with excellent parallel scaling performance. IM3D is based on fast indexing of scattering integrals and the SRIM stopping power database, and allows the user a choice of Constructive Solid Geometry (CSG) or Finite Element Triangle Mesh (FETM) method for constructing 3D shapes and microstructures. For 2D films and multilayers, IM3D perfectly reproduces SRIM results, and can be ?10(2) times faster in serial execution and >?10(4) times faster using parallel computation. For 3D problems, it provides a fast approach for analyzing the spatial distributions of primary displacements and defect generation under ion irradiation. Herein we also provide a detailed discussion of our open-source collision cascade physics engine, revealing the true meaning and limitations of the "Quick Kinchin-Pease" and "Full Cascades" options. The issues of femtosecond to picosecond timescales in defining displacement versus damage, the limitation of the displacements per atom (DPA) unit in quantifying radiation damage (such as inadequacy in quantifying degree of chemical mixing), are discussed. PMID:26658477

  16. IM3D: A parallel Monte Carlo code for efficient simulations of primary radiation displacements and damage in 3D geometry

    PubMed Central

    Li, Yong Gang; Yang, Yang; Short, Michael P.; Ding, Ze Jun; Zeng, Zhi; Li, Ju

    2015-01-01

    SRIM-like codes have limitations in describing general 3D geometries, for modeling radiation displacements and damage in nanostructured materials. A universal, computationally efficient and massively parallel 3D Monte Carlo code, IM3D, has been developed with excellent parallel scaling performance. IM3D is based on fast indexing of scattering integrals and the SRIM stopping power database, and allows the user a choice of Constructive Solid Geometry (CSG) or Finite Element Triangle Mesh (FETM) method for constructing 3D shapes and microstructures. For 2D films and multilayers, IM3D perfectly reproduces SRIM results, and can be ?102 times faster in serial execution and >?104 times faster using parallel computation. For 3D problems, it provides a fast approach for analyzing the spatial distributions of primary displacements and defect generation under ion irradiation. Herein we also provide a detailed discussion of our open-source collision cascade physics engine, revealing the true meaning and limitations of the “Quick Kinchin-Pease” and “Full Cascades” options. The issues of femtosecond to picosecond timescales in defining displacement versus damage, the limitation of the displacements per atom (DPA) unit in quantifying radiation damage (such as inadequacy in quantifying degree of chemical mixing), are discussed. PMID:26658477

  17. Influence of major fault zones on 3-D coupled fluid and heat transport for the Brandenburg region (NE German Basin)

    NASA Astrophysics Data System (ADS)

    Cherubini, Y.; Cacace, M.; Scheck-Wenderoth, M.; Noack, V.

    2014-04-01

    To quantify the influence of major fault zones on the groundwater and thermal field, 3-D finite-element simulations are carried out. Two fault zones - the Gardelegen and Lausitz escarpments - have been integrated into an existing 3-D structure of the Brandenburg region in northeastern Germany. Different geological scenarios in terms of modelled fault permeability have been considered, of which two end-member models are discussed in detail. In addition, results from these end-member simulations are compared to a reference case in which no faults are considered. The study provides interesting results with respect to the interaction between faults and surrounding sediments and how it affects the regional groundwater circulation system and thermal field. Impermeable fault zones seem to induce no remarkable effects on the temperature distribution; that is, the thermal field is similar to the no-fault model. In addition, tight faults have only a local impact on the fluid circulation within a domain of limited spatial extent centred on the fault zone. Fluid flow from the surrounding aquifers is deviated in close proximity of the fault zones acting as hydraulic barriers that prevent lateral fluid inflow into the fault zones. Permeable fault zones induce a pronounced thermal signature with alternating up- and downward flow along the same structures. Fluid flow along the plane of the faults is principally driven by existing hydraulic head gradients, but may be further enhanced by buoyancy forces. Within recharge domains, fluid advection induces a strong cooling in the fault zones. Discharge domains at shallow depth levels (~<-450 m) are instead characterized by the presence of rising warm fluids, which results in a local increase of temperatures which are up to 15 °C higher than in the no-fault case. This study is the first attempt to investigate the impact of major fault zones on a 3-D basin scale for the coupled fluid and heat transport in the Brandenburg region. The approach enables a quantification of mechanisms controlling fluid flow and temperature distribution both within surrounding sediments and fault zones as well as how they dynamically interact. Therefore, the results from the modelling provide useful indications for geothermal energy exploration.

  18. Development methods of steam turbines 3D geometry optical control for effective heat power equipment quality improvement

    NASA Astrophysics Data System (ADS)

    Dvoynishnikov, Sergey

    2014-08-01

    A method for steam turbines 3D geometry optical control for effective heat power equipment quality improvement is proposed. It is shown that technical characteristics of the developed optical phase triangulation method for precision contactless geometry diagnostics of steam turbines meet modern requirements to 3D geometry measuring instruments and are perspective for further development. It is shown that used phase step method provides measurement error less than 0.024% of measurement range.

  19. The Derivation of Fault Volumetric Properties from 3D Trace Maps Using Outcrop Constrained Discrete Fracture Network Models

    NASA Astrophysics Data System (ADS)

    Hodgetts, David; Seers, Thomas

    2015-04-01

    Fault systems are important structural elements within many petroleum reservoirs, acting as potential conduits, baffles or barriers to hydrocarbon migration. Large, seismic-scale faults often serve as reservoir bounding seals, forming structural traps which have proved to be prolific plays in many petroleum provinces. Though inconspicuous within most seismic datasets, smaller subsidiary faults, commonly within the damage zones of parent structures, may also play an important role. These smaller faults typically form narrow, tabular low permeability zones which serve to compartmentalize the reservoir, negatively impacting upon hydrocarbon recovery. Though considerable improvements have been made in the visualization field to reservoir-scale fault systems with the advent of 3D seismic surveys, the occlusion of smaller scale faults in such datasets is a source of significant uncertainty during prospect evaluation. The limited capacity of conventional subsurface datasets to probe the spatial distribution of these smaller scale faults has given rise to a large number of outcrop based studies, allowing their intensity, connectivity and size distributions to be explored in detail. Whilst these studies have yielded an improved theoretical understanding of the style and distribution of sub-seismic scale faults, the ability to transform observations from outcrop to quantities that are relatable to reservoir volumes remains elusive. These issues arise from the fact that outcrops essentially offer a pseudo-3D window into the rock volume, making the extrapolation of surficial fault properties such as areal density (fracture length per unit area: P21), to equivalent volumetric measures (i.e. fracture area per unit volume: P32) applicable to fracture modelling extremely challenging. Here, we demonstrate an approach which harnesses advances in the extraction of 3D trace maps from surface reconstructions using calibrated image sequences, in combination with a novel semi-deterministic, outcrop constrained discrete fracture network modeling code to derive volumetric fault intensity measures (fault area per unit volume / fault volume per unit volume). Producing per-vertex measures of volumetric intensity; our method captures the spatial variability in 3D fault density across a surveyed outcrop, enabling first order controls to be probed. We demonstrate our approach on pervasively faulted exposures of a Permian aged reservoir analogue from the Vale of Eden Basin, UK.

  20. Estimating the detectability of faults in 3D-seismic data - A valuable input to Induced Seismic Hazard Assessment (ISHA)

    NASA Astrophysics Data System (ADS)

    Goertz, A.; Kraft, T.; Wiemer, S.; Spada, M.

    2012-12-01

    In the past several years, some geotechnical operations that inject fluid into the deep subsurface, such as oil and gas development, waste disposal, and geothermal energy development, have been found or suspected to cause small to moderate sized earthquakes. In several cases the largest events occurred on previously unmapped faults, within or in close vicinity to the operated reservoirs. The obvious conclusion drawn from this finding, also expressed in most recently published best practice guidelines and recommendations, is to avoid injecting into faults. Yet, how certain can we be that all faults relevant to induced seismic hazard have been identified, even around well studied sites? Here we present a probabilistic approach to assess the capability of detecting faults by means of 3D seismic imaging. First, we populate a model reservoir with seed faults of random orientation and slip direction. Drawing random samples from a Gutenberg-Richter distribution, each seed fault is assigned a magnitude and corresponding size using standard scaling relations based on a circular rupture model. We then compute the minimum resolution of a 3D seismic survey for given acquisition parameters and frequency bandwidth. Assuming a random distribution of medium properties and distribution of image frequencies, we obtain a probability that a fault of a given size is detected, or respectively overlooked, by the 3D seismic. Weighting the initial Gutenberg-Richter fault size distribution with the probability of imaging a fault, we obtain a modified fault size distribution in the imaged volume from which we can constrain the maximum magnitude to be considered in the seismic hazard assessment of the operation. We can further quantify the value of information associated with the seismic image by comparing the expected insured value loss between the image-weighted and the unweighted hazard estimates.

  1. The internal geometry of salt structures - A first look using 3D seismic data from the Zechstein of the Netherlands

    NASA Astrophysics Data System (ADS)

    Van Gent, Heijn; Urai, Janos L.; de Keijzer, Martin

    2011-03-01

    We present a first look at the large-scale, complexly folded and faulted internal structure of Zechstein salt bodies in NW Europe using 3D reflection seismic reflection data from two surveys on the Groningen High and the Cleaver Bank High. We focus on a relatively brittle, folded and boudinaged, claystone-carbonate-anhydrite layer (the Z3 stringer) enclosed in ductile salt. A first classification of the structures is presented and compared with observations from salt mines and analogue and numerical models. Z3 stringers not only are reservoirs for hydrocarbons but can also present a serious drilling problem in some areas. Results of this study could provide the basis for better prediction of zones of drilling problems. More generally, the techniques presented here can be used to predict the internal structure of salt bodies, to estimate the geometry of economic deposits of all kinds and locate zones suitable for storage caverns. Structures observed include an extensive network of zones with increased thickness of the stringer. These we infer to have formed by early diagenesis, karstification, gravitational sliding and associated local sedimentation. Later, this template was deformed into large-scale folds and boudins during salt tectonics. Salt flow was rarely plane strain, producing complex fold and boudin geometries. Deformation was further complicated by the stronger zones of increased thickness, which led to strongly non-cylindrical structures. We present some indications that the thicker zones also influence the locations of later suprasalt structures, suggesting a feedback between the early internal evolution of this salt giant and later salt tectonics. This study opens the possibility to study the internal structure of the Zechstein and other salt giants in 3D using this technique, exposing a previously poorly known structure which is comparable in size and complexity to the internal parts of some orogens.

  2. 3D Digital Surveying and Modelling of Cave Geometry: Application to Paleolithic Rock Art

    PubMed Central

    González-Aguilera, Diego; Muñoz-Nieto, Angel; Gómez-Lahoz, Javier; Herrero-Pascual, Jesus; Gutierrez-Alonso, Gabriel

    2009-01-01

    3D digital surveying and modelling of cave geometry represents a relevant approach for research, management and preservation of our cultural and geological legacy. In this paper, a multi-sensor approach based on a terrestrial laser scanner, a high-resolution digital camera and a total station is presented. Two emblematic caves of Paleolithic human occupation and situated in northern Spain, “Las Caldas” and “Peña de Candamo”, have been chosen to put in practise this approach. As a result, an integral and multi-scalable 3D model is generated which may allow other scientists, pre-historians, geologists…, to work on two different levels, integrating different Paleolithic Art datasets: (1) a basic level based on the accurate and metric support provided by the laser scanner; and (2) a advanced level using the range and image-based modelling. PMID:22399958

  3. 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, E. and Papathanassiou, G.: 'Aftershock relocation and frequency-size distribution, stress inversion and seismotectonic setting of the 7 August 2013 M=5.4 earthquake in Kallidromon Mountain, central Greece', Tectonophysics, vol. 617, pp. 101-113, 2014 [4] Maravelakis, E., Bilalis, N., Mantzorou, I., Konstantaras, A. and Antoniadis, A.: '3D modelling of the oldest olive tree of the world', International Journal Of Computational Engineering Research, vol. 2 (2), pp. 340-347, 2012 [5] Konstantaras, A., Katsifarakis, E, Maravelakis, E, Skounakis, E, Kokkinos, E. and Karapidakis, E.: 'Intelligent spatial-clustering of seismicity in the vicinity of the Hellenic seismic arc', Earth Science Research, vol. 1 (2), pp. 1- 10, 2012 [6] Georgoulas, G., Konstantaras, A., Katsifarakis, E., Stylios, C., Maravelakis, E and Vachtsevanos, G.: 'Seismic-mass" density-based algorithm for spatio-temporal clustering', Expert Systems with Applications, vol. 40 (10), pp. 4183-4189, 2013 [7] Konstantaras, A.: 'Classification of Distinct Seismic Regions and Regional Temporal Modelling of Seismicity in the Vicinity of the Hellenic Seismic Arc', Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of', vol. 99, pp. 1-7, 2013

  4. Are climate signals observed in the 3-D ice surface geometry of mountain glaciers?

    NASA Astrophysics Data System (ADS)

    Hayes, R.; Clark, C.

    2013-12-01

    Mountain glaciers are among the fastest responding components of the cryosphere to climatic perturbations and are thus an essential parameter in climate system monitoring. The intrinsic link between glacier mass balance and the organisation of ice flow vectors result in a situation where glacier surface profiles tend towards differing geometries in the accumulation and ablation area. These differing geometries can be readily explained, as a function of the mass balance budget, by principles of continuum mechanics and the need for glaciers to conserve mass. However, little work has been done to provide empirical evidence to link these distinct changes in ice surface geometry with observed glacier climate signals such as ELA and mass balance. With the use of remotely sensed optical imagery, global DEM datasets and geospatial methods, we present empirical observations that assess the extent to which ice surface morphology reflects the current state of mountain glaciers in a changing climate. Despite the complex relationship between mass balance, ice flow dynamics and climate, the findings suggest that observations of 3-D ice surface geometry may provide significant insights into how glaciers are responding to climate perturbations.

  5. 3D analysis of geometry and flow changes in a limestone fracture during dissolution

    NASA Astrophysics Data System (ADS)

    Noiriel, Catherine; Gouze, Philippe; Madé, Benoît

    2013-04-01

    SummaryThe effects of reactive transport on fracture geometry and fluid flow were investigated through an integrated experimental and modelling approach. A fractured limestone sample (90% calcite) was injected with an acidic CO2-rich solution over a period of 55 h to induce carbonate dissolution. The changes in fracture geometry and related parameters are reported for six data sets obtained from synchrotron X-ray micro-tomography experiments. A series of algorithms was used to extract the aperture and fracture walls from 3D images and allowed quantification of the geometry changes with an optical resolution of 4.91 ?m. In addition, measurement of fluid chemistry, hydraulic tests and computation of Navier-Stokes flow constrained the characterisation of the dissolution process. The effects of reactive transport on fracture geometry and fluid flow were then discussed. The presence of silicates in the rocks led to heterogeneous dissolution at the micro-scale, despite dissolution appearing to be quite homogeneous at sample-scale. No formation of preferential flow pathways was noticed, although heterogeneous dissolution at the micro-scale led to fracture walls and aperture decorrelation, and to modification of the flow velocity profiles in the fracture.

  6. SU-E-J-128: 3D Surface Reconstruction of a Patient Using Epipolar Geometry

    SciTech Connect

    Kotoku, J; Nakabayashi, S; Kumagai, S; Ishibashi, T; Kobayashi, T; Haga, A; Saotome, N; Arai, N

    2014-06-01

    Purpose: To obtain a 3D surface data of a patient in a non-invasive way can substantially reduce the effort for the registration of patient in radiation therapy. To achieve this goal, we introduced the multiple view stereo technique, which is known to be used in a 'photo tourism' on the internet. Methods: 70 Images were taken with a digital single-lens reflex camera from different angles and positions. The camera positions and angles were inferred later in the reconstruction step. A sparse 3D reconstruction model was locating by SIFT features, which is robust for rotation and shift variance, in each image. We then found a set of correspondences between pairs of images by computing the fundamental matrix using the eight-point algorithm with RANSAC. After the pair matching, we optimized the parameter including camera positions to minimize the reprojection error by use of bundle adjustment technique (non-linear optimization). As a final step, we performed dense reconstruction and associate a color with each point using the library of PMVS. Results: Surface data were reconstructed well by visual inspection. The human skin is reconstructed well, althogh the reconstruction was time-consuming for direct use in daily clinical practice. Conclusion: 3D reconstruction using multi view stereo geometry is a promising tool for reducing the effort of patient setup. This work was supported by JSPS KAKENHI(25861128)

  7. Image-based reconstruction of 3D myocardial infarct geometry for patient specific applications

    NASA Astrophysics Data System (ADS)

    Ukwatta, Eranga; Rajchl, Martin; White, James; Pashakhanloo, Farhad; Herzka, Daniel A.; McVeigh, Elliot; Lardo, Albert C.; Trayanova, Natalia; Vadakkumpadan, Fijoy

    2015-03-01

    Accurate reconstruction of the three-dimensional (3D) geometry of a myocardial infarct from two-dimensional (2D) multi-slice image sequences has important applications in the clinical evaluation and treatment of patients with ischemic cardiomyopathy. However, this reconstruction is challenging because the resolution of common clinical scans used to acquire infarct structure, such as short-axis, late-gadolinium enhanced cardiac magnetic resonance (LGE-CMR) images, is low, especially in the out-of-plane direction. In this study, we propose a novel technique to reconstruct the 3D infarct geometry from low resolution clinical images. Our methodology is based on a function called logarithm of odds (LogOdds), which allows the broader class of linear combinations in the LogOdds vector space as opposed to being limited to only a convex combination in the binary label space. To assess the efficacy of the method, we used high-resolution LGE-CMR images of 36 human hearts in vivo, and 3 canine hearts ex vivo. The infarct was manually segmented in each slice of the acquired images, and the manually segmented data were downsampled to clinical resolution. The developed method was then applied to the downsampled image slices, and the resulting reconstructions were compared with the manually segmented data. Several existing reconstruction techniques were also implemented, and compared with the proposed method. The results show that the LogOdds method significantly outperforms all the other tested methods in terms of region overlap.

  8. Image-based Reconstruction of 3D Myocardial Infarct Geometry for Patient Specific Applications

    PubMed Central

    Ukwatta, Eranga; Rajchl, Martin; White, James; Pashakhanloo, Farhad; Herzka, Daniel A.; McVeigh, Elliot; Lardo, Albert C.; Trayanova, Natalia; Vadakkumpadan, Fijoy

    2015-01-01

    Accurate reconstruction of the three-dimensional (3D) geometry of a myocardial infarct from two-dimensional (2D) multi-slice image sequences has important applications in the clinical evaluation and treatment of patients with ischemic cardiomyopathy. However, this reconstruction is challenging because the resolution of common clinical scans used to acquire infarct structure, such as short-axis, late-gadolinium enhanced cardiac magnetic resonance (LGE-CMR) images, is low, especially in the out-of-plane direction. In this study, we propose a novel technique to reconstruct the 3D infarct geometry from low resolution clinical images. Our methodology is based on a function called logarithm of odds (LogOdds), which allows the broader class of linear combinations in the LogOdds vector space as opposed to being limited to only a convex combination in the binary label space. To assess the efficacy of the method, we used high-resolution LGE-CMR images of 36 human hearts in vivo, and 3 canine hearts ex vivo. The infarct was manually segmented in each slice of the acquired images, and the manually segmented data were downsampled to clinical resolution. The developed method was then applied to the downsampled image slices, and the resulting reconstructions were compared with the manually segmented data. Several existing reconstruction techniques were also implemented, and compared with the proposed method. The results show that the LogOdds method significantly outperforms all the other tested methods in terms of region overlap. PMID:26633913

  9. Amoeboid migration mode adaption in quasi-3D spatial density gradients of varying lattice geometry

    NASA Astrophysics Data System (ADS)

    Gorelashvili, Mari; Emmert, Martin; Hodeck, Kai F.; Heinrich, Doris

    2014-07-01

    Cell migration processes are controlled by sensitive interaction with external cues such as topographic structures of the cell’s environment. Here, we present systematically controlled assays to investigate the specific effects of spatial density and local geometry of topographic structure on amoeboid migration of Dictyostelium discoideum cells. This is realized by well-controlled fabrication of quasi-3D pillar fields exhibiting a systematic variation of inter-pillar distance and pillar lattice geometry. By time-resolved local mean-squared displacement analysis of amoeboid migration, we can extract motility parameters in order to elucidate the details of amoeboid migration mechanisms and consolidate them in a two-state contact-controlled motility model, distinguishing directed and random phases. Specifically, we find that directed pillar-to-pillar runs are found preferably in high pillar density regions, and cells in directed motion states sense pillars as attractive topographic stimuli. In contrast, cell motion in random probing states is inhibited by high pillar density, where pillars act as obstacles for cell motion. In a gradient spatial density, these mechanisms lead to topographic guidance of cells, with a general trend towards a regime of inter-pillar spacing close to the cell diameter. In locally anisotropic pillar environments, cell migration is often found to be damped due to competing attraction by different pillars in close proximity and due to lack of other potential stimuli in the vicinity of the cell. Further, we demonstrate topographic cell guidance reflecting the lattice geometry of the quasi-3D environment by distinct preferences in migration direction. Our findings allow to specifically control amoeboid cell migration by purely topographic effects and thus, to induce active cell guidance. These tools hold prospects for medical applications like improved wound treatment, or invasion assays for immune cells.

  10. The contribution of 3D restoration for the reconstruction of pre-thrusting basin geometries in fold-and-thrust belts

    NASA Astrophysics Data System (ADS)

    Aquè, R.; Tavarnelli, E.

    2012-04-01

    The three-dimensional (3D) reconstruction of complex geological settings and of original, pre-thrusting basin geometry is one of the challenges for modern structural geology. It has indeed a critical role in many industrial applications, such as in the hydrocarbon exploration. By using commercial specific softwares to produce balanced cross-sections and inferred 3D reconstructions (2DMove™, Gocad™), we modelled a portion of the Umbria-Marche fold-and-thrust belt, in the outer zones of the Northern Apennines of Italy, in order to infer the pre-thrusting geometry of the Mesozoic-Cenozoic extensional basins and to test the applicability of existing computer tools in areas that have experienced the effects of positive tectonic inversion. In the study area, the accurate reconstruction of the structural setting, cross-cut relationships and timing of the deformation, was inferred by using field data, map analysis and cross-section balancing techniques. The structural overprinting relationships among the investigated thrusts made it possible to infer a general piggy-back thrusting sequence, with new thrust faults to the East, developed in the footwall of formerly emplaced thrust sheets, in the West. This allowed to sequentially remove the effects of the deformation for progressively older structures, and to back-strip the thrust sheets in sequential evolutionary steps, in order to reconstruct a viable pre-thrusting template. Four balanced cross-sections have been drawn, providing the initial skeleton for 3D modelling, together with the map trace of the major tectonic features. The cross-sections and the geological map have been digitized and geo-referred in 2D-Move™. Starting from the inferred geometries, a coherent 3D model was built in Gocad™. The surfaces represent post-thrust normal faults, thrust planes, and pre-thrust normal faults, and five key stratigraphic surfaces, from bottom; the base and top of the Calcare Massiccio fm. (Lower Liassic), the base of the Maiolica fm. (Titonian), the base and the top of the Marne a Fucoidi fm. (Upper Albian-Lower Cenomanian). The main pre-thrusting normal faults have been projected using their map and cross-section traces, keeping into account the thickness variation of the selected stratigraphic reference; the complete detail of the condensed and complete stratigraphic sequence was considered in cross-section only. The combination of balanced cross-sections, 3D modelling and restoration techniques, sequentially applied to fold-and-thrust belts, provides effective tools to unravel the geometry of the pre-thrusting geometries and depict the architecture of the sedimentary basins. Even if the surface restoration techniques are strongly dependant on the reconstructed surface geometry (i.e. the mesh of the surface and the obtained cutoffs along a fault surface), the results are comparable to the calculations obtained from classical 2D balancing techniques. The results of this work seem to encourage for further applicability of similar methods to other areas of the Northern Apennines, and to geologically complex areas in general.

  11. Fast hologram synthesis for 3D geometry models using graphics hardware

    NASA Astrophysics Data System (ADS)

    Petz, Christoph; Magnor, Marcus

    2003-05-01

    The holographic visualization of three-dimensional object geometry still represents a major challenge in computational holography research. Besides the development of suitable holographic display devices, the fast calculation of the hologram's interference pattern for complex-shaped three-dimensional objects is an important pre-requisite of any interactive holographic display system. We present a fast method for rendering full-parallax holograms using a standard PC with a consumer-market graphics card. To calculate the hologram of a 3D object, scaled and translated versions of the interference pattern of simple primitives, e.g. point sources, are superimposed. The hologram is built up completely on-board the graphics card. To avoid numerical inaccuracies due to limited frame-buffer resolution, we use a hierarchical approach. Using an NVidia Geforce4 graphics card, the proposed algorithm takes 1.0 second to calculate the 512×512-pixel hologram of 1024 primitives.

  12. Tunneling Analyst: A 3D GIS extension for rock mass classification and fault zone analysis in tunneling

    NASA Astrophysics Data System (ADS)

    Choi, Yosoon; Yoon, Seo-Youn; Park, Hyeong-Dong

    2009-06-01

    In this study, an extension called Tunneling Analyst (TA) has been developed in ArcScene 3D GIS software, part of the ArcGIS software package. It dramatically extends the functionalities of ArcScene because it allows: (1) estimation of the 3D distribution of rock mass rating (RMR) values using borehole and geophysical exploration data, (2) the modeling of 3D discontinuity planes such as faults from field-based structural measurements, and (3) analysis of 3D intersections and 3D buffer zones between proposed tunnel alignments and some discontinuities. Because TA can handle and visualize both 2D and 3D geological data in a single GIS environment, the tedious tasks required for data conversion between various software packages can be reduced significantly. The application to the Daecheong tunneling project in Korea shows that TA could present a rational solution to evaluating the rock mass classes along a proposed tunnel alignment and can also provide specific 3D spatial query tools to support the tunnel design work. This paper describes the concept and details of the development and implementation of TA.

  13. The influence of fault geometry on small strike-slip fault mechanics

    NASA Astrophysics Data System (ADS)

    Ritz, Elizabeth; Pollard, David D.; Ferris, Michael

    2015-04-01

    Meter-scale subvertical strike-slip fault traces in the central Californian Sierra Nevada exhibit geometric complexities that significantly contribute to their mechanical behavior. Sections of faults that opened at depth channelized fluid flow, as evidenced by hydrothermal mineral infillings and alteration haloes. Thin sections show a variation in the style of ductile deformation of infill along the fault, with greater intensities of deformation along restraining bends. Orthorectified photomosaics of outcrops provide model geometries and parameter constraints used in a two-dimensional displacement discontinuity model incorporating a complementarity algorithm. Model results show that fault shape influences the distribution of opening, and consequently the spatial distribution of fluid conduits. Geometric irregularities are present at many scales, and sections of opening occur along both releasing and restraining bends. Model sensitivity tests focus on boundary conditions along the fault: frictional properties on closed sections and fluid pressure within sections of opening. The influence of the remote stress state varies along a non-planar fault, complicating the relationships between remote stresses, frictional properties, slip, and opening. Discontinuous sections of opening along model faults are similar in spatial distribution and aperture to the epidote infill assemblages observed in the field.

  14. High-Performance and Omnidirectional Thin-Film Amorphous Silicon Solar Cell Modules Achieved by 3D Geometry Design.

    PubMed

    Yu, Dongliang; Yin, Min; Lu, Linfeng; Zhang, Hanzhong; Chen, Xiaoyuan; Zhu, Xufei; Che, Jianfei; Li, Dongdong

    2015-11-01

    High-performance thin-film hydrogenated amorphous silicon solar cells are achieved by combining macroscale 3D tubular substrates and nanoscaled 3D cone-like antireflective films. The tubular geometry delivers a series of advantages for large-scale deployment of photovoltaics, such as omnidirectional performance, easier encapsulation, decreased wind resistance, and easy integration with a second device inside the glass tube. PMID:26418573

  15. High resolution 3D laser scanner measurements of a strike-slip fault quantify its morphological anisotropy at all scales

    E-print Network

    Renard, Francois; Marsan, Davd; Schmittbuhl, Jean

    2008-01-01

    The surface roughness of a recently exhumed strikeslip fault plane has been measured by three independent 3D portable laser scanners. Digital elevation models of several fault surface areas, from 1 m2 to 600 m2, have been measured at a resolution ranging from 5 mm to 80 mm. Out of plane height fluctuations are described by non-Gaussian distribution with exponential long range tails. Statistical scaling analyses show that the striated fault surface exhibits self-affine scaling invariance with a small but significant directional morphological anisotropy that can be described by two scaling roughness exponents, H1 = 0.7 in the direction of slip and H2 = 0.8 perpendicular to the direction of slip.

  16. The Ellipsoid Factor for Quantification of Rods, Plates, and Intermediate Forms in 3D Geometries

    PubMed Central

    Doube, Michael

    2015-01-01

    The ellipsoid factor (EF) is a method for the local determination of the rod- or plate-like nature of porous or spongy continua. EF at a point within a 3D structure is defined as the difference in axis ratios of the greatest ellipsoid that fits inside the structure and that contains the point of interest, and ranges from ?1 for strongly oblate (discus-shaped) ellipsoids, to +1 for strongly prolate (javelin-shaped) ellipsoids. For an ellipsoid with axes a???b???c, EF?=?a/b???b/c. Here, EF is demonstrated in a Java plugin, “Ellipsoid Factor” for ImageJ, distributed in the BoneJ plugin collection. Ellipsoid Factor utilizes an ellipsoid optimization algorithm, which assumes that maximal ellipsoids are centered on the medial axis, then dilates, rotates, and translates slightly each ellipsoid until it cannot increase in volume any further. EF successfully identifies rods, plates, and intermediate structures within trabecular bone, and summarizes the distribution of geometries with an overall EF mean and SD, EF histogram, and Flinn diagram displaying a/b versus b/c. EF is released to the community for testing, use, and improvement. PMID:25762979

  17. Strike-slip fault geometry in Turkey and its influence on earthquake activity

    NASA Technical Reports Server (NTRS)

    Barka, A. A.; Kadinsky-Cade, K.

    1988-01-01

    The geometry of Turkish strike-slip faults is reviewed, showing that fault geometry plays an important role in controlling the location of large earthquake rupture segments along the fault zones. It is found that large earthquake ruptures generally do not propagate past individual stepovers that are wider than 5 km or bends that have angles greater than about 30 degrees. It is suggested that certain geometric patterns are responsible for strain accumulation along portions of the fault zone. It is shown that fault geometry plays a role in the characteristics of earthquake behavior and that aftershocks and swarm activity are often associated with releasing areas.

  18. Poly 3D fault modeling scripts/data for permeability potential of Washington State geothermal prospects

    DOE Data Explorer

    Michael Swyer

    2015-02-05

    Matlab scripts/functions and data used to build Poly3D models and create permeability potential GIS layers for 1) Mount St Helen's, 2) Wind River Valley, and 3) Mount Baker geothermal prospect areas located in Washington state.

  19. High precision Differential Earthquake Location in 3D models: Evidence for a rheological barrier controlling the microseismicity at the Irpinia fault zone in southern Apennines

    NASA Astrophysics Data System (ADS)

    De Landro, Grazia; Amoroso, Ortensia; Alfredo Stabile, Tony; Matrullo, Emanuela; Lomax, Anthony; Zollo, Aldo

    2015-04-01

    A non-linear, global-search, probabilistic, double-difference earthquake location technique is illustrated. The main advantages of this method are the determination of comprehensive and complete solutions through the probability density function (PDF), the use of differential arrival-times as data, and the possibility to use a 3D velocity model both for absolute and relative locations, essential to obtain accurate differentials locations in structurally complex geological media. The joint use of this methodology and an accurate differential times data-set allowed us to carry out an high-resolution, earthquake location analysis, which helped to characterize the active fault geometries in the studied region. We investigated the recent micro-seismicity occurring at the Campanian-Lucanian Apennines, in the crustal volume embedding the fault system which generated the 1980, M 6.9 earthquake in Irpinia. In order to obtain highly accurate seismicity locations we applied the method to the P and S arrival time data set from 1312 events (M<3) that occurred from August 2005 to April 2011, and used the 3D P- and S-wave velocity models, optimized for the area under study. Both catalogue and cross-correlation first arrival-times have been used. The refined seismicity locations show that the events occur in a volume delimited by the faults activated during the 1980 Irpinia M 6.9 earthquake on sub-parallel, predominantly normal faults. Corresponding to a contact zone between different rheology rock formations (carbonate platform and basin residuals), we evidence an abrupt interruption of the seismicity across a SW-NE oriented structural discontinuity. This "barrier" appears to be located in the area bounded by the fault segments activated during the first (0 sec) and the second (20 sec) rupture episodes of the 80's Irpinia earthquake. We hypothesize that this geometrical barrier can have played a key role during the 1980 Irpinia event, and possibly controlled the delayed times of activation of the two rupture segments.

  20. High-precision differential earthquake location in 3-D models: evidence for a rheological barrier controlling the microseismicity at the Irpinia fault zone in southern Apennines

    NASA Astrophysics Data System (ADS)

    De Landro, Grazia; Amoroso, Ortensia; Stabile, Tony Alfredo; Matrullo, Emanuela; Lomax, Antony; Zollo, Aldo

    2015-12-01

    A non-linear, global-search, probabilistic, double-difference earthquake location technique is illustrated. The main advantages of this method are the determination of comprehensive and complete solutions through the probability density function (PDF), the use of differential arrival times as data and the possibility to use a 3-D velocity model both for absolute and double-difference locations, all of which help to obtain accurate differential locations in structurally complex geological media. The joint use of this methodology and an accurate differential time data set allowed us to carry out a high-resolution, earthquake location analysis, which helps to characterize the active fault geometries in the studied region. We investigated the recent microseismicity occurring at the Campanian-Lucanian Apennines in the crustal volume embedding the fault system that generated the 1980 MS 6.9 earthquake in Irpinia. In order to obtain highly accurate seismicity locations, we applied the method to the P and S arrival time data set from 1312 events (ML < 3.1) that occurred from August 2005 to April 2011 and used the 3-D P- and S-wave velocity models optimized for the area under study. Both manually refined and cross-correlation refined absolute arrival times have been used. The refined seismicity locations show that the events occur in a volume delimited by the faults activated during the 1980 MS 6.9 Irpinia earthquake on subparallel, predominantly normal faults. We find an abrupt interruption of the seismicity across an SW-NE oriented structural discontinuity corresponding to a contact zone between different rheology rock formations (carbonate platform and basin residuals). This `barrier' appears to be located in the area bounded by the fault segments activated during the first (0 s) and the second (18 s) rupture episodes of the 1980s Irpinia earthquake. We hypothesize that this geometrical barrier could have played a key role during the 1980 Irpinia event, and possibly controlled the delayed times of activation of the two rupture segments.

  1. Subsurface image of the Mariánské Lázne Fault (Czech Republic) by 3-D GPR and DC resistivity measurement

    NASA Astrophysics Data System (ADS)

    Tábo?ík, P.; Karousová, M.; Št?pan?íková, P.; Fischer, T.

    2012-04-01

    This study deals with application of two geoelectrical methods in order to study geophysical expression of logged geological structures exposed in an artificial trench and their continuation laterally and to the depth. The trench was excavated within the Mariánské Lázn? fault zone, which borders the mountain front of the Krušné hory Mts towards the Cheb basin and intersects the seismoactive zone of Nový Kostel. The present geodynamic activity in the area of Cheb basin is manifested by earthquake swarms and ubiquitous emanations of mantle-derived carbon-dioxide. The trench survey has identified a subvertical fault plane whose recent activity is being investigated by structural and sedimentological analyses, and geochronological methods. Because the very narrow zone of faulting expression within the Quaternary deposits (few tens of cm) does not enable its direct identification by geophysical methods, we used ground truth information from the trench to study possible geophysical attributes of the fault. To this purpose we applied 3D ground penetrating radar (GPR) survey and a 2D multi-electrode DC electrical resistivity tomography (ERT). The GPR survey was carried out using the shielded 250 MHz antenna on rectangular grid 40 x 60 meters. The detailed ERT measurements were performed on one profile of 200m length with 1 m electrode spacing and Wenner-Schlumberger electrode array. The ERT measurements have identified a shallow high-resistivity body, which corresponds to the sandy and gravelly deposits documented in the trench. The fault intersects the body on its southern margin, and the expected low-resistivity zone of the fault is thus masked by the high-resistivity sediments. The 3D GPR survey showed high amplitude reflections that are clearly associated with the high-resistivity body, which is separated from the surrounding area with missing reflections. Comparison with the ERT results shows that zones of attenuated GPR signal correspond to the lower resistive substratum (< 150 ?m) of the clay-rich colluvium and deep-weathered crystalline basement. The stacked GPR time slices reveal that besides the strong reflections in the area of sands and gravels a distinct zone of scattered reflections occur along the expected direction of the fault, which corresponds to the fault strike measured in the trench. We presume that the reflections are created by a high-resistive material similar to that being associated to the sandy-gravelly body. It turned out that application of the two geophysical methods itself would not be able to find the subsurface geophysical expression of the fault. Nevertheless, the geophysical survey was crucial for finding a prolongation of the fault further from the trench and also for tracking its occurrence in depth. This was possible thanks to the a-priori geological data obtained from the trench survey. Keywords: the Mariánské Lázn? Fault, Cheb basin, ground penetrating radar, electrical resistivity tomography, trenching

  2. Mantle wedge flow pattern and thermal structure in Northeast Japan: Effects of oblique subduction and 3-D slab geometry

    NASA Astrophysics Data System (ADS)

    Wada, Ikuko; He, Jiangheng; Hasegawa, Akira; Nakajima, Junichi

    2015-09-01

    We develop a 3-D thermal model for the Northeast Japan subduction margin, using a realistic slab geometry for the subducting Pacific plate, and investigate the effects of oblique subduction and 3-D slab geometry on the mantle wedge flow pattern and the thermal structure. In the Tohoku region, the mantle wedge flow pattern is nearly two-dimensional resulting in a thermal structure similar to those obtained by a 2-D model, owing to the simple slab geometry and subduction nearly perpendicular to the margin. However, in Hokkaido, oblique subduction leads to 3-D mantle wedge flow with northerly inflow and west-northwestward outflow and also results in lower temperatures in the shallow part of the mantle wedge than in Tohoku due to lower sinking rate of the slab. Between Hokkaido and Tohoku, the slab has a hinge-like shape due to a relatively sharp change in the dip direction. In this hinge zone, northerly mantle inflow from Hokkaido and westerly mantle inflow from Tohoku converge, discouraging inflow from northwest and resulting in a cooler mantle wedge. The model-predicted mantle wedge flow patterns are consistent with observed seismic anisotropy and may explain the orientations of volcanic cross-chains. The predicted 3-D thermal structure correlates well with the along-arc variations in the location of the frontal arc volcanoes and help to provide new insights into the surface heat flow pattern and the down-dip extent of interplate earthquakes.

  3. Development and application of a 3-D geometry/mass model for LDEF satellite ionizing radiation assessments

    NASA Technical Reports Server (NTRS)

    Colborn, B. L.; Armstrong, T. W.

    1992-01-01

    A computer model of the three dimensional geometry and material distributions for the LDEF spacecraft, experiment trays, and, for selected trays, the components of experiments within a tray was developed for use in ionizing radiation assessments. The model is being applied to provide 3-D shielding distributions around radiation dosimeters to aid in data interpretation, particularly in assessing the directional properties of the radiation exposure. Also, the model has been interfaced with radiation transport codes for 3-D dosimetry response predictions and for calculations related to determining the accuracy of trapped proton and cosmic ray environment models. The methodology is described used in developing the 3-D LDEF model and the level of detail incorporated. Currently, the trays modeled in detail are F2, F8, and H12 and H3. Applications of the model which are discussed include the 3-D shielding distributions around various dosimeters, the influence of shielding on dosimetry responses, and comparisons of dose predictions based on the present 3-D model vs those from 1-D geometry model approximations used in initial estimates.

  4. Stratigraphic architecture and fault offsets of alluvial terraces at Te Marua, Wellington fault, New Zealand, revealed by pseudo-3D GPR investigation

    NASA Astrophysics Data System (ADS)

    Beauprêtre, S.; Manighetti, I.; Garambois, S.; Malavieille, J.; Dominguez, S.

    2013-08-01

    earthquake slips on faults are commonly determined by measuring morphological offsets at current ground surface. Because those offsets might not always be well preserved, we examine whether the first 10 m below ground surface contains relevant information to complement them. We focus on the Te Marua site, New Zealand, where 11 alluvial terraces have been dextrally offset by the Wellington fault. We investigated the site using pseudo-3D Ground Penetrating Radar and also produced a high-resolution digital elevation model (DEM) of the zone to constrain the surface slip record. The GPR data reveal additional information: (1) they image the 3D stratigraphic architecture of the seven youngest terraces and show that they are strath terraces carved into graywacke bedrock. Each strath surface is overlain by 3-5 m of horizontally bedded gravel sheets, including two pronounced and traceable reflectors; (2) thanks to the multilayer architecture, terrace risers and channels are imaged at three depths and their lateral offsets can be measured three to four times, constraining respective offsets and their uncertainties more reliably; and (3) the offsets are better preserved in the subsurface than at the ground surface, likely due to subsequent erosion-deposition on the latter. From surface and subsurface data, we infer that Te Marua has recorded six cumulative offsets of 2.9, 7.6, 18, 23.2, 26, and 31 m (± 1-2 m). Large earthquakes on southern Wellington fault might produce 3-5 m of slip, slightly less than previously proposed. Pseudo-3D GPR thus provides a novel paleoseismological tool to complement and refine surface investigations.

  5. Knowledge Construction of 3D Geometry Concepts and Processes within a Virtual Reality Learning Environment

    E-print Network

    Roe, Paul

    in Virtual Reality (VR) environments. A recent development of VR technology, often described as desktop VR (Pimentel & Teixeira, 1995), has significantly changed the feasibility of having VR on personal computers. Desktop VR utilises real-time 3D graphics to define a virtual 3D space in which users can freely

  6. QUANTIFYING UNCERTAINTIES IN GROUND MOTION SIMULATIONS FOR SCENARIO EARTHQUAKES ON THE HAYWARD-RODGERS CREEK FAULT SYSTEM USING THE USGS 3D VELOCITY MODEL AND REALISTIC PSEUDODYNAMIC RUPTURE MODELS

    SciTech Connect

    Rodgers, A; Xie, X

    2008-01-09

    This project seeks to compute ground motions for large (M>6.5) scenario earthquakes on the Hayward Fault using realistic pseudodynamic ruptures, the USGS three-dimensional (3D) velocity model and anelastic finite difference simulations on parallel computers. We will attempt to bound ground motions by performing simulations with suites of stochastic rupture models for a given scenario on a given fault segment. The outcome of this effort will provide the average, spread and range of ground motions that can be expected from likely large earthquake scenarios. The resulting ground motions will be based on first-principles calculations and include the effects of slip heterogeneity, fault geometry and directivity, however, they will be band-limited to relatively low-frequency (< 1 Hz).

  7. 3D Faulting Numerical Model Related To 2009 L'Aquila Earthquake Based On DInSAR Observations

    NASA Astrophysics Data System (ADS)

    Castaldo, Raffaele; Tizzani, Pietro; Solaro, Giuseppe; Pepe, Susi; Lanari, Riccardo

    2014-05-01

    We investigate the surface displacements in the area affected by the April 6, 2009 L'Aquila earthquake (Central Italy) through an advanced 3D numerical modeling approach, by exploiting DInSAR deformation velocity maps based on ENVISAT (Ascending and Descending orbits) and COSMO-SkyMed data (Ascending orbit). We benefited from the available geological and geophysical information to investigate the impact of known buried structures on the modulation of the observed ground deformation field; in this context we implemented the a priori information in a Finite Element (FE) Environment considering a structural mechanical physical approach. The performed analysis demonstrate that the displacement pattern associated with the Mw 6.3 main-shock event is consistent with the activation of several fault segments of the Paganica fault. In particular, we analyzed the seismic events in a structural mechanical context under the plane stress mode approximation to solve for the retrieved displacements. We defined the sub-domain setting of the 3D FEM model using the information derived from the CROOP M-15 seismic line. We assumed stationarity and linear elasticity of the involved materials by considering a solution of classical equilibrium mechanical equations. We evolved our model through two stages: the model compacted under the weight of the rock successions (gravity loading) until it reached a stable equilibrium. At the second stage (co-seismic), where the stresses were released through a slip along the faults, by using an optimization procedure we retrieved: (i) the active seismogenic structures responsible for the observed ground deformation, (ii) the effects of the different mechanical constraints on the ground deformation pattern and (iii) the spatial distribution of the retrieved stress field. We evaluated the boundary setting best fit configuration responsible for the observed ground deformation. To this aim, we first generated several forward structural mechanical models, obtained through the activation of different structural segments; then, we compared the synthetic (related to the performed forward model) and the measured ground deformation fields, in order to select the minimum RMS solution. We search for the best model results using an optimization algorithm based on the genetic algorithm, providing an accurate spatial characterization of ground deformation. Our results improve kinematic solutions for the Paganica fault and allow identification of additional fault segments that have contributed to the observed complex ground deformation pattern. The FEM-based methodology is applicable to other seismic areas where the complexity of buried structures plays a fundamental role on the associated surface deformation pattern.

  8. The differences in the development of Rayleigh-Taylor instability in 2D and 3D geometries

    NASA Astrophysics Data System (ADS)

    Kuchugov, P. A.; Rozanov, V. B.; Zmitrenko, N. V.

    2014-06-01

    Results are presented from theoretical analysis and numerical simulations aimed to clarify specific features of Rayleigh-Taylor instability in 2D and 3D geometries. Two series of simulations, one with an isolated single-mode perturbation of the interface and the other with a random density perturbation, were performed. It is shown that the relative evolutions of integral characteristics for the first and the second series are different in 2D and 3D geometries. An attempt is made to interpret this result in the framework of the previously developed evolutionary approach based on the concept of the "critical age" of the perturbation (where, by the age is meant the product of the wavenumber and amplitude). The critical age corresponds to the destruction of the main mushroom-like structure formed during the development of Rayleigh-Taylor instability due to the onset of the secondary Kelvin-Helmholtz instability.

  9. Reassembling 3D Thin Fragments of Unknown Geometry in Cultural Heritage

    NASA Astrophysics Data System (ADS)

    Zheng, S. Y.; Huang, R. Y.; Li, J.; Wang, Z.

    2014-05-01

    Many fragile antiques had already been broken upon being discovered at archaeology sites. The fragments of these objects cannot be effectively interpreted and studied unless they are successfully reassembled. However, there still exists many problems in the reassembly procedure in existing methods, such as the numerical instabilities of curvature and torsion based methods, the limitation of geometric assumption, and the error accumulation of the pairwise matching approach, etc. Regarding these problems, this paper proposed an approach to match the fragments to each other for their original 3D reconstruction. Instead of the curvatures and torsions, the approach is based on establishing a local Cartesian coordinate at every point of the 3D contour curves. First of all, the 3D meshes of the fragments are acquired by a structure-light based method, with the corresponding 3D contour curves extracted from the outer boundaries. Then, the contour curves are matched and aligned to each other by estimating all the possible 3D rigid transformations of the curve pairs with our defined local Cartesian coordinates, and then the maximum likelihood rigid transformations are selected. Finally, a global refinement is introduced to adjust the alignment errors and improve the final reassembling accuracy. In addition, experiments with two groups of fragments suggest that this approach cannot only match and align fragments effectively, but also improve the accuracy significantly. Comparing with the original 3D model acquired before being broken, the final reassembling accuracy reaches 0.47 mm.

  10. Three-dimensional geometry of axial magma chamber roof and faults at Lucky Strike volcano on the Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Combier, Violaine; Seher, Tim; Singh, Satish C.; Crawford, Wayne C.; Cannat, Mathilde; Escartín, Javier; Dusunur, Doga

    2015-08-01

    We present results from three-dimensional (3-D) processing of seismic reflection data, acquired in June 2005 over the Lucky Strike volcano on the Mid-Atlantic Ridge as a part of the Seismic Study for Monitoring of the Mid-Atlantic Ridge survey. We use a 3-D tomographic velocity model derived from a coincident ocean bottom seismometer experiment to depth convert the poststack time-migrated seismic volume and provide 3-D geometry of the axial magma chamber roof, fault reflectors, and layer 2A gradient marker. We also generate a high-resolution bathymetric map using the seismic reflection data. The magma chamber roof is imaged at 3.4 ± 0.4 km depth beneath the volcano, and major faults are imaged with dips ranging between 33° and 50°. The magma chamber roof geometry is consistent with a focused melt supply at the segment center and steep across-axis thermal gradients as indicated by the proximity between the magma chamber and nearby faults. Fault scarps on the seafloor and fault dip at depth indicate that tectonic extension accounts for at least 10% of the total plate separation. Shallow dipping reflectors imaged in the upper crust beneath the volcano flanks are interpreted as buried lava flow surfaces.

  11. Restoring complex folded geometries in 3D using paleomagnetic vectors; a new tool to validate underground reconstructions

    NASA Astrophysics Data System (ADS)

    José Ramón, Mª; Pueyo, Emilio L.; Briz, José Luis; Caumon, Guillaume; Fernández, Óscar; Ciria, José Carlos; Pocovi, Andrés; Ros, Luis H.

    2013-04-01

    Three-dimensional reconstructions of the underground involve the integration of discrete and heterogeneous datasets and have significant socio- economic implications. The problem arises when there are limited data to build 3D models or when deformation processes are complex; these reasons inspired the development of restoration methods to validate subsurface reconstructions. The restoration is based on the application of simple geometric (or mechanic) laws that help reduce the uncertainty and increase geomodel accuracy. Apart from mechanical approaches, geometric methods are based on the initial assumption of global conservation of volume during deformation in addition to the paleo-horizontality of the stratigraphic horizons in the undeformed stage. The problem is that the bedding plane cannot be used as a three-dimensional reference system, because a single vector defines it and additional constraints are required. This is particularly important when dealing with complex structures, such as non-cylindrical structures and the superposition of non-coaxial geometries. In this context, paleomagnetism (known in both the deformed and undeformed stages) can contribute to building a more complete reference system and to reducing the uncertainty in restoration processes. The use of paleomagnetism in restoration tools was suggested in the early 1990's and only a few quantitative map-view applications have been developed since then. In this contribution, we introduce the two first surface restoration methods that use paleomagnetic vectors as a primary reference. The first one is a simple geometric approach based on the piecewise restoration of a triangulated surface into which paleomagnetic variables can be easily incorporated. It is valid for complexly folded structures. The surface is modelled by a mesh and the method starts from a pin-element. Triangles are laid flat and then fitted together to minimize distances between common vertices and paleomagnetic error. However, this first approach is very sensitive to the density and type of triangulation of the mesh, as well as the location of the pin-element. The second one is based on a parametric approach (gOcad code), whereby a curvilinear coordinate system is computed on the folded surface by numerical optimization. We use paleomagnetic data to define constraints for the computation of this frame, which significantly increases the robustness of the restoration method. We assess the accuracy of the restoration algorithms using computer and analogue models. We have developed a new methodology to simulate the paleomagnetic vectors in the models and we are able to obtain reliable 3D images of them under a CT scan. These models allow us to set up a known initial undeformed surface (a horizontal horizon and its magnetic reference). We then perform a forward deformation to obtain a controlled deformed surface. Subsequently, we apply a restoration method to that deformed surface, and compare the result from the restored state with the initial undeformed surface. With an ideal restoration method the two states should match perfectly and, therefore, we can quantify the quality of the restoration by measuring the differences between them. Future work on the method includes the restoration of volumes (now only horizons) and faults (discontinuous deformation). The application to real case studies from the Pyrenean External Sierras, apart from reliable geometric reconstructions of the structures, has to consider the distribution of vectors, which is limited to the surface although it is densely sampled, and the quality, reliability and resolution of real datasets.

  12. Fault strength in Marmara region inferred from the geometry of the principle stress axes and fault orientations: A case study for the Prince's Islands fault segment

    NASA Astrophysics Data System (ADS)

    Pinar, Ali; Coskun, Zeynep; Mert, Aydin; Kalafat, Dogan

    2015-04-01

    The general consensus based on historical earthquake data point out that the last major moment release on the Prince's islands fault was in 1766 which in turn signals an increased seismic risk for Istanbul Metropolitan area considering the fact that most of the 20 mm/yr GPS derived slip rate for the region is accommodated mostly by that fault segment. The orientation of the Prince's islands fault segment overlaps with the NW-SE direction of the maximum principle stress axis derived from the focal mechanism solutions of the large and moderate sized earthquakes occurred in the Marmara region. As such, the NW-SE trending fault segment translates the motion between the two E-W trending branches of the North Anatolian fault zone; one extending from the Gulf of Izmit towards Ç?narc?k basin and the other extending between offshore Bak?rköy and Silivri. The basic relation between the orientation of the maximum and minimum principal stress axes, the shear and normal stresses, and the orientation of a fault provides clue on the strength of a fault, i.e., its frictional coefficient. Here, the angle between the fault normal and maximum compressive stress axis is a key parameter where fault normal and fault parallel maximum compressive stress might be a necessary and sufficient condition for a creeping event. That relation also implies that when the trend of the sigma-1 axis is close to the strike of the fault the shear stress acting on the fault plane approaches zero. On the other hand, the ratio between the shear and normal stresses acting on a fault plane is proportional to the coefficient of frictional coefficient of the fault. Accordingly, the geometry between the Prince's islands fault segment and a maximum principal stress axis matches a weak fault model. In the frame of the presentation we analyze seismological data acquired in Marmara region and interpret the results in conjuction with the above mentioned weak fault model.

  13. Applications of Geometry Processing CudaHull: Fast parallel 3D convex hull on the GPU

    E-print Network

    El-Sana, Jihad

    algorithm for computing the convex hull of a set of points in 3D using the CUDA programming model, can be reduced to the convex hull. Fast convex-hull algorithms are useful for interactive appli environments [3]. Numerous algorithms were proposed to compute the convex hull of a finite set of points

  14. Mechanical constraints imposed by 3D cellular geometry and arrangement modulate growth patterns in the Arabidopsis embryo

    PubMed Central

    Bassel, George W.; Stamm, Petra; Mosca, Gabriella; Barbier de Reuille, Pierre; Gibbs, Daniel J.; Winter, Robin; Janka, Ales; Holdsworth, Michael J.; Smith, Richard S.

    2014-01-01

    Morphogenesis occurs in 3D space over time and is guided by coordinated gene expression programs. Here we use postembryonic development in Arabidopsis plants to investigate the genetic control of growth. We demonstrate that gene expression driving the production of the growth-stimulating hormone gibberellic acid and downstream growth factors is first induced within the radicle tip of the embryo. The center of cell expansion is, however, spatially displaced from the center of gene expression. Because the rapidly growing cells have very different geometry from that of those at the tip, we hypothesized that mechanical factors may contribute to this growth displacement. To this end we developed 3D finite-element method models of growing custom-designed digital embryos at cellular resolution. We used this framework to conceptualize how cell size, shape, and topology influence tissue growth and to explore the interplay of geometrical and genetic inputs into growth distribution. Our simulations showed that mechanical constraints are sufficient to explain the disconnect between the experimentally observed spatiotemporal patterns of gene expression and early postembryonic growth. The center of cell expansion is the position where genetic and mechanical facilitators of growth converge. We have thus uncovered a mechanism whereby 3D cellular geometry helps direct where genetically specified growth takes place. PMID:24912195

  15. 3D Microstructural Investigation of Experimentally Deformed Smectite-rich San Andreas Fault Gouge from the Southern Deforming Zone (SAFOD)

    NASA Astrophysics Data System (ADS)

    Wojatschke, J.; Scuderi, M.; Warr, L. N.; Saffer, D. M.; Marone, C.

    2014-12-01

    Smectite clays have been recognized to play an important role in fault zone strength and slip behavior. Due to their interaction with fluids, hydrological properties change and lead to a weakening of the fault. Some of the weakest clay gouge has been recovered from SAFOD core along the active Central Deforming Zone of the San Andreas Fault, with a coefficient of friction as low as µ=0.095. We conducted laboratory shearing experiments to investigate the microstructural fabric development and frictional behavior of powders and natural intact fault gouge to characterize differences in mechanical and hydrological properties caused by varying smectite clay fabrics. In this study we used almost pure clay powder from SAF gouge (<63 µm) and mixed it with varying amounts of quartz or SAF clasts (120-500 µm). We sheared gouge layers in a double-direct shear configuration housed in a pressure vessel, at an effective normal stress of ?'n = 5 MPa and under saturated conditions with a pore pressure of 2 MPa. We used a relatively low normal stress to allow recovery of material after the experiments for microstructural investigation. We sheared the layers at a constant velocity of 10 ?m/s, followed by a series of slide-hold-slide tests to characterize frictional properties. After the experiments all samples were analyzed using a focused ion beam - scanning electron microscope (FIB-SEM) in order to reconstruct the 3D microstructures associated with experimentally induced polished slip surfaces at the micro- to nanometer scale. Initial results document clear stages of clay fabric development related to the clay to clast ratio, which exhibit similarities with naturally developed fabrics. In smectite-dominated mixtures, principle slip surfaces develop parallel to each other, but these features are modified as the clast content increases. With higher clay content strain hardening becomes more prominent. Clay minerals and fabric developed during shear have a strong effect on gouge mechanical and hydrological properties, and therefore likely play a key role in controlling fault gouge slip behavior at seismogenic depth.

  16. Insights into the 3D architecture of an active caldera ring-fault at Tendürek volcano through modeling of geodetic data

    NASA Astrophysics Data System (ADS)

    Bathke, H.; Nikkhoo, M.; Holohan, E. P.; Walter, T. R.

    2015-07-01

    The three-dimensional assessment of ring-fault geometries and kinematics at active caldera volcanoes is typically limited by sparse field, geodetic or seismological data, or by only partial ring-fault rupture or slip. Here we use a novel combination of spatially dense InSAR time-series data, numerical models and sand-box experiments to determine the three-dimensional geometry and kinematics of a sub-surface ring-fault at Tendürek volcano in Turkey. The InSAR data reveal that the area within the ring-fault not only subsides, but also shows substantial westward-directed lateral movement. The models and experiments explain this as a consequence of a 'sliding-trapdoor' ring-fault architecture that is mostly composed of outward-inclined reverse segments, most markedly so on the volcano's western flanks but includes inward-inclined normal segments on its eastern flanks. Furthermore, the model ring-fault exhibits dextral and sinistral strike-slip components that are roughly bilaterally distributed onto its northern and southern segments, respectively. Our more complex numerical model describes the deformation at Tendürek better than an analytical solution for a single rectangular dislocation in a half-space. Comparison to ring-faults defined at Glen Coe, Fernandina and Bárðarbunga calderas suggests that 'sliding-trapdoor' ring-fault geometries may be common in nature and should therefore be considered in geological and geophysical interpretations of ring-faults at different scales worldwide.

  17. GIS based 3D visualization of subsurface and surface lineaments / faults and their geological significance, northern tamil nadu, India

    NASA Astrophysics Data System (ADS)

    Saravanavel, J.; Ramasamy, S. M.

    2014-11-01

    The study area falls in the southern part of the Indian Peninsular comprising hard crystalline rocks of Archaeozoic and Proterozoic Era. In the present study, the GIS based 3D visualizations of gravity, magnetic, resistivity and topographic datasets were made and therefrom the basement lineaments, shallow subsurface lineaments and surface lineaments/faults were interpreted. These lineaments were classified as category-1 i.e. exclusively surface lineaments, category-2 i.e. surface lineaments having connectivity with shallow subsurface lineaments and category-3 i.e. surface lineaments having connectivity with shallow subsurface lineaments and basement lineaments. These three classified lineaments were analyzed in conjunction with known mineral occurrences and historical seismicity of the study area in GIS environment. The study revealed that the category-3 NNE-SSW to NE-SW lineaments have greater control over the mineral occurrences and the N-S, NNE-SSW and NE-SW, faults/lineaments control the seismicities in the study area.

  18. 3D seismic detection of shallow faults and fluid migration pathways offshore Southern Costa Rica: Application of neural-network meta-attributes

    NASA Astrophysics Data System (ADS)

    Kluesner, J. W.; Silver, E. A.; Nale, S. M.; Bangs, N. L.; McIntosh, K. D.

    2013-12-01

    We employ a seismic meta-attribute workflow to detect and analyze probable faults and fluid-pathways in 3D within the sedimentary section offshore Southern Costa Rica. During the CRISP seismic survey in 2011 we collected an 11 x 55 km grid of 3D seismic reflection data and high-resolvability EM122 multibeam data, with coverage extending from the incoming plate to the outer-shelf. We mapped numerous seafloor seep indicators, with distributions ranging from the lower-slope to ~15 km landward of the shelf break [Kluesner et al., 2013, G3, doi:10.1002/ggge.20058; Silver et al., this meeting]. We used the OpendTect software package to calculate meta-attribute volumes from the 3D seismic data in order to detect and visualize seismic discontinuities in 3D. This methodology consists of dip-steered filtering to pre-condition the data, followed by combining a set of advanced dip-steered seismic attributes into a single object probability attribute using a user-trained neural-network pattern-recognition algorithm. The parameters of the advanced seismic attributes are set for optimal detection of the desired geologic discontinuity (e.g. faults or fluid-pathways). The product is a measure of probability for the desired target that ranges between 0 and 1, with 1 representing the highest probability. Within the sedimentary section of the CRISP survey the results indicate focused fluid-migration pathways along dense networks of intersecting normal faults with approximately N-S and E-W trends. This pattern extends from the middle slope to the outer-shelf region. Dense clusters of fluid-migration pathways are located above basement highs and deeply rooted reverse faults [see Bangs et al., this meeting], including a dense zone of fluid-pathways imaged below IODP Site U1413. In addition, fault intersections frequently show an increased signal of fluid-migration and these zones may act as major conduits for fluid-flow through the sedimentary cover. Imaged fluid pathways root into high-backscatter pockmarks and mounds on the seafloor, which are located atop folds and clustered along intersecting fault planes. Combining the fault and fluid-pathway attribute volumes reveals qualitative first order information on fault seal integrity within the CRISP survey region, highlighting which faults and/or fault sections appear to be sealing or leaking within the sedimentary section. These results provide 3D insight into the fluid-flow behavior offshore southern Costa Rica and suggest that fluids escaping through the deeper crustal rocks are predominantly channeled along faults in the sedimentary cover, especially at fault intersections.

  19. Detailed parametric study of Casimir forces in the Casimir Polder approximation for nontrivial 3D geometries

    NASA Astrophysics Data System (ADS)

    Sedmik, R.; Vasiljevich, I.; Tajmar, M.

    2007-04-01

    We present a parametric numerical study conducted with the finite element code CasimirSim developed by ARC Seibersdorf research. This simulation has already been applied to two dimensional geometries in the past and showed agreement with exact theoretical predictions between 100 nm and 10 ?m. In the current investigation the code has been enhanced to compute arbitrary, nontrivial, fully three dimensional geometries for any material given by its density and dielectric polarizability. For calculation of the Casimir energy the simple Casimir Polder r -7 model is used. This approach is known to be of limited accuracy due to the assumption of perfect additivity of dipole interactions. Nonetheless, it can be used to give approximate predictions for sharply curved geometries inaccessible to other approximative schemes such as for example the established Proximity Force Approximation. In the current study, we show in detail the dependence of errors upon physical and numerical parameters. After verification with the plate plate geometry experimentally relevant geometries such as sphere over plate or crossed cylinders are assessed. Finally, the simulation is applied to the more sophisticated geometries of stacked spherical shells, a gear wheel, and a cantilever, showing up some interesting properties.

  20. Applying and validating the RANS-3D flow-solver for evaluating a subsonic serpentine diffuser geometry

    NASA Technical Reports Server (NTRS)

    Fletcher, Michael J.; Won, Mark J.; Cosentino, Gary B.; Te, Alexander

    1993-01-01

    Subsonic inlet ducts for advanced, high-performance aircraft are evolving towards complex three-dimensional shapes for reasons of overall integration and weight. These factors lead to diffuser geometries that may sacrifice inlet performance, unless careful attention to design details and boundary layer management techniques are employed. The ability of viscous computational fluid dynamic (CFD) analysis of such geometries to aid the aircraft configurator in this complex design problem is herein examined. The RANS-3D Reynolds-Averaged Navier-Stokes solver is applied to model the complex flowfield occurring in a representative diffuser geometry and the solutions are compared to experimental results from a static test of the inlet duct. The computational results are shown to compare very favorably with experimental results over a range of mass flow rates, including those involving large amounts of separation in the diffuser. In addition, a novel grid topology is presented, and two turbulence models are evaluated in this study as part of the RANS-3D code.

  1. Geometry of laccolith margins: 2D and 3D models of the Late Paleozoic Halle Volcanic Complex (Germany)

    NASA Astrophysics Data System (ADS)

    Schmiedel, T.; Breitkreuz, C.; Görz, I.; Ehling, B.-C.

    2015-03-01

    Well data and core samples from the Late Paleozoic Halle Volcanic Complex (HVC) have been used to describe the geometry of the rhyolitic porphyritic laccoliths and their margins. The HVC formed between 301 and 292 Ma in the intramontane Saale basin, and it comprises mainly rhyolitic subvolcanic bodies (~300 km3) as well as minor lava flows and volcaniclastic deposits. The major HVC laccolith units display aspect ratios ranging between 0.04 and 0.07, and they are separated by tilted and deformed Carboniferous-Permian host sediments. For the margin of the Landsberg laccolith, a major coarsely porphyritic unit of the HVC, an exceptional data set of 63 wells concentrated in an area of 10 km2 reaching to depth of 710 m exists. It was used to explore the 3D geometry and textures, and to deduce an intrusion model. For a 3D visualization of the Landsberg laccolith margin, Geological Object Computer Aided Design; Paradigm® software (GOCAD) was used. Curve objects have been derived from the intrusion-host contacts. Automated GOCAD® methods for 3D modelling failed. As a result, manual refinement was essential. A major finding of the 3D modelling is the presence of prolate sediment rafts, up to 1,400 m in length and up to 500 m in thickness, surrounded by Landsberg rhyolite. The sedimentary rafts dip away from the laccolith centre. The engulfing laccolith sheets reach thickness of 100-300 m. For other HVC laccolith units (Löbejün, Petersberg, Brachstedt), well data reveal vertical rhyolite/sediment contacts or magma lobes fingering into the host sediments. HVC laccolith contact textures include small-scale shearing of the intruding magma and of the host sediment. In addition, internal shear zones have been detected inside the rhyolite bodies. The present study suggests that the emplacement of successive magma sheets was an important process during laccolith growth in the HVC.

  2. Subsonic 3-D surface panel method for rapid analysis of multiple geometry perturbations

    NASA Technical Reports Server (NTRS)

    Bristow, D. R.; Hawk, J. D.; Thomas, J. L.

    1982-01-01

    For any baseline aircraft configuration, a matrix of partial derivatives of surface velocity potential with respect to geometry coordinates is calculated. Linear extrapolation is then used to analyze the subcritical potential flow corresponding to a series of arbitrary small geometry perturbations. Each perturbation analysis is more than an order of magnitude more efficient than a conventional panel method solution because no influence coefficients are calculated and no large system of linear algebraic equations is solved. Wing and wing-fuselage examples are presented to demonstrate that the predicted pressure distributions are nearly exact for large changes to wing camber, thickness, and leading edge radius.

  3. Software development for a 3D gravity inversion and application to study of the Border Ranges Fault System, south-central Alaska

    NASA Astrophysics Data System (ADS)

    Cardenas, Rolando

    The Border Ranges Fault System (BRFS) bounds the Cook Inlet and Susitna Basins, and is an important petroleum province within south-central Alaska. A primary goal of our research is to test several plausible models of structure along the BRFS using a novel three-dimensional inversion technique utilizing gravity data, constrained with other geophysical, borehole and surface geological information. This research involves the development of 3D inversion modeling software using C++ Builder from Embarcadero's XE2 Suite. The novel inversion approach directly models known geology with a priori uncertainties assigned to the geologic model to allow researchers to compare alternative interpretations. This technique was developed to evaluate three-dimensional structure in regions of complex and poorly known geology. Our software computes the density solution of a geologic structure by utilizing its location within the gravity field as well as the gridded surface files of known topography and subsurface units. The total gravitational effect of each body is calculated with a series of semi-infinite vertical line elements which improves the computational efficiency of computing forward models of structures with extremely complex geometry. The inversion algorithm considers a priori geophysical constraints and uncertainties due to gravity measurements, surface file inconsistencies, and forward calculations in the model solution. In addition, a Kalman-based filtering estimator is used to minimize our observation and processing noise. The estimator allows the a posteriori covariance matrix to avoid its dependence on the non-singularity of the Jacobian (model) matrix.

  4. 3-D in vivo brain tumor geometry study by scaling analysis

    NASA Astrophysics Data System (ADS)

    Torres Hoyos, F.; Martín-Landrove, M.

    2012-02-01

    A new method, based on scaling analysis, is used to calculate fractal dimension and local roughness exponents to characterize in vivo 3-D tumor growth in the brain. Image acquisition was made according to the standard protocol used for brain radiotherapy and radiosurgery, i.e., axial, coronal and sagittal magnetic resonance T1-weighted images, and comprising the brain volume for image registration. Image segmentation was performed by the application of the k-means procedure upon contrasted images. We analyzed glioblastomas, astrocytomas, metastases and benign brain tumors. The results show significant variations of the parameters depending on the tumor stage and histological origin.

  5. Templated 3D ultrathin CVD graphite networks with controllable geometry: synthesis and application as supercapacitor electrodes.

    PubMed

    Hsia, Ben; Kim, Mun Sek; Luna, Lunet E; Mair, Nisha R; Kim, Yongkwan; Carraro, Carlo; Maboudian, Roya

    2014-11-12

    Three-dimensional ultrathin graphitic foams are grown via chemical vapor deposition on templated Ni scaffolds, which are electrodeposited on a close-packed array of polystyrene microspheres. After removal of the Ni, free-standing foams composed of conjoined hollow ultrathin graphite spheres are obtained. Control over the pore size and foam thickness is demonstrated. The graphitic foam is tested as a supercapacitor electrode, exhibiting electrochemical double-layer capacitance values that compare well to those obtained with the state-of-the-art 3D graphene materials. PMID:25318008

  6. Higher order global differentiability local approximations for 2-D and 3-D distorted element geometries

    E-print Network

    Maduri, Rajesh Kumar

    2008-02-01

    approximations in designing finite element computational processes has been demonstrated by Surana and co-workers [1-4]. It has been shown by Surana et al. [5] that when the element geometry is rectangular, higher order global differentiability approximations can...

  7. Geometry and convergence analysis of algorithms for registration of 3D shapes

    E-print Network

    Pottmann, Helmut

    . This requires the simultaneous registration of a number of point clouds. Another industrial application Geometric Modeling and Industrial Geometry Group Vienna University of Technology, Austria pottmann motion (trans- lation and rotation) that aligns a cloud of measurement points of a workpiece #12;to

  8. The Emergence of 3D Geometry from Children's (Teacher-Guided) Classification Tasks

    ERIC Educational Resources Information Center

    Roth, Wolff-Michael; Thom, Jennifer S.

    2009-01-01

    Geometry, classification, and the classification of geometrical objects are integral aspects of recent curriculum documents in mathematics education. Such curriculum documents, however, leave open how the "work" of classifying objects according to geometrical properties can be accomplished given that the knowledge of these properties is the…

  9. The Need (?) for Descriptive Geometry in a World of 3D Modeling.

    ERIC Educational Resources Information Center

    Croft, Frank M. Jr.

    1998-01-01

    Evaluates the use of modern CAD methods to solve geometric problems. Solves descriptive geometry problems using the layout and position of the successive auxiliary views from the projection of three-dimensional figures onto a two-dimensional plane of paper. (CCM)

  10. Responsive culture platform to examine the influence of microenvironmental geometry on cell function in 3D.

    PubMed

    Kloxin, April M; Lewis, Katherine J R; DeForest, Cole A; Seedorf, Gregory; Tibbitt, Mark W; Balasubramaniam, Vivek; Anseth, Kristi S

    2012-12-01

    We describe the development of a well-based cell culture platform that enables experimenters to control the geometry and connectivity of cellular microenvironments spatiotemporally. The base material is a hydrogel comprised of photolabile and enzyme-labile crosslinks and pendant cell adhesion sequences, enabling spatially-specific, in situ patterning with light and cell-dictated microenvironment remodeling through enzyme secretion. Arrays of culture wells of varying shape and size were patterned into the hydrogel surface using photolithography, where well depth was correlated with irradiation dose. The geometry of these devices can be subsequently modified through sequential patterning, while simultaneously monitoring changes in cell geometry and connectivity. Towards establishing the utility of these devices for dynamic evaluation of the influence of physical cues on tissue morphogenesis, the effect of well shape on lung epithelial cell differentiation (i.e., primary mouse alveolar type II cells, ATII cells) was assessed. Shapes inspired by alveoli were degraded into hydrogel surfaces. ATII cells were seeded within the well-based arrays and encapsulated by the addition of a top hydrogel layer. Cell differentiation in response to these geometries was characterized over 7 days of culture with immunocytochemistry (surfactant protein C, ATII; T1? protein, alveolar type I (ATI) differentiated epithelial cells) and confocal image analysis. Individual cell clusters were further connected by eroding channels between wells during culture via controlled two-photon irradiation. Collectively, these studies demonstrate the development and utility of responsive hydrogel culture devices to study how a range of microenvironment geometries of evolving shape and connectivity might influence or direct cell function. PMID:23138879

  11. 3D coseismic deformation inversion of Wenchuan Ms8.0 earthquake with D-InSAR and the fault movement model

    NASA Astrophysics Data System (ADS)

    Chen, Y. L.; Wu, J. C.; Guo, L. Y.; Wang, X. Y.; Tan, H. B.; Shen, C. Y.

    2015-08-01

    Conventional D-InSAR (Differential SAR Interferometry) can only monitor 1-D surface deformation along LOS (line of sight) direction. In order to overcome this limitation and extract 3-D coseismic displacement, we combine the LOS displacement derived from D-InSAR technology, the OKADA elastic half space dislocation model theory, jointly the surface rupture distribution by field investigations and the fault model inverted by GPS, level data and gravity survey to retrieve the directions of surface co-seismic displacement, and then have got Wenchuan Ms8.0 Earthquake 3D displacement. Firstly, thirty six L-band PALSAR images of six adjacent ascending tracks are processed with D-InSAR technology to obtain the coseismic displacements along LOS direction. According to the OKADA model and the thrust fault movement model of the Long-Men-Shan Fault , we specify the three directions of surface coseismic displacements. And thus the 3D coseismic displacement field is then recovered by using LOS displacement and relevant geometric projection formulas, obviously including horizontal displacements field and vertical deformation contour maps. By comparing with the 3D displacement estimated from OKADA dislocation model and fault model, the displacement retrieved in this study can give more detail, and reflect seismic characteristics more truly.

  12. Validation of Direct Numerical Simulations in 3D pore geometries and Large-Eddy Simulations

    NASA Astrophysics Data System (ADS)

    Naumov, Dmitri

    2013-04-01

    Numerical solutions of the Navier-Stokes Equations became more popular in recent decades with increasingly accessible and powerful computational resources. Simulations in reconstructed or artificial pore geometries are often performed to gain insight into microscopic fluid flow structures or are used for upscaling quantities of interest, like hydraulic conductivity. A physically adequate representation of pore scale flow fields requires analysis of large domains in combination with turbulence models. We solve incompressible Navier-Stokes Equations in a cubic lattice and cubic close packing of spheres placed in a square duct with Direct Numerical Simulations (DNS) and analyze the validity of the results. The influence of the number of spheres and mesh discretization is investigated for fluid flow up to Reynolds numbers of 5000 based on the spheres' diameter. The numerical simulations are performed with the OpenFOAM open-source CFD software. We statistically investigate spatial and temporal properties of the resulting fluid flow field and its kinetic energy spectra, and compare them to Large-Eddy Simulations (LES) performed for the same geometries. Differences between the DNS and LES are discussed together with upscaled hydraulic properties with respect to the number of spheres and the Reynolds number.

  13. Fault and joint geometry at Raft River Geothermal Area, Idaho

    NASA Astrophysics Data System (ADS)

    Guth, L. R.; Bruhn, R. L.; Beck, S. L.

    1981-07-01

    Raft River geothermal reservoir is formed by fractures in sedimentary strata of the Miocene and Pliocene salt lake formation. The fracturing is most intense at the base of the salt lake formation, along a decollement that dips eastward at less than 50 on top of metamorphosed precambrian and lower paleozoic rocks. Core taken from less than 200 m above the decollement contains two sets of normal faults. The major set of faults dips between 500 and 700. These faults occur as conjugate pairs that are bisected by vertical extension fractures. The second set of faults dips 100 to 200 and may parallel part of the basal decollement or reflect the presence of listric normal faults in the upper plate. Surface joints form two suborthogonal sets that dip vertically. East-northeast-striking joints are most frequent on the limbs of the Jim Sage anticline, a large fold that is associated with the geothermal field.

  14. Flow properties along field lines in a 3-D tilted-dipole geometry

    NASA Technical Reports Server (NTRS)

    Pizzo, V. J.

    1995-01-01

    A 3-D MHD simulation of a global, tilted-dipole solar wind flow pattern is analyzed to determine flow properties along individual magnetic field lines. In the model, flow conditions near the Sun are chosen to provide a reasonable match to the interplanetary configuration prevailing during the recent south polar passage by Ulysses, i.e., a streamer belt inclined approximately 30 deg to the solar equator and speeds ranging from 325-800 km/s. Field lines all across the stream pattern are traced from 1 to 10 AU by following the motion of marker particles embedded in the flow. It is found that those field lines threading the core of the interaction region are subject to significant latitudinal and relative longitudinal displacement over this range of heliocentric distance. Thus, observations taken at a fixed latitude in the inner solar system sample, over the course of a solar rotation, field lines which connect to a range of latitudes in the outer heliosphere. Maps of the field line displacements are presented to help visualize these connections. In addition, it is found that depending upon the location relative to the CIR structure, the radial evolution of fluid elements frozen to different field lines can deviate considerably from that of the canonical solar wind. That is, for selected subsets of field lines, large speed changes (not just at shocks) can be experienced; the density variation can be far from 1/r(exp 2), and the magnetic field intensity need not decay monotonically with distance.

  15. 3D simulations of the early stages of AGN jets: geometry, thermodynamics and backflow

    E-print Network

    Cielo, S; Macciò, A V; Romeo, A D; Silk, J

    2013-01-01

    We investigate the interplay between jets from Active Galactic Nuclei (AGNs) and the surrounding InterStellar Medium (ISM) through full 3D, high resolution, Adaptive Mesh Refinement simulations performed with the FLASH code. We follow the jet- ISM system for several Myr in its transition from an early, compact source to an extended one including a large cocoon. During the jet evolution, we identify three major evolutionary stages and we find that, contrary to the prediction of popular theoretical models, none of the simulations shows a self-similar behavior. We also follow the evolution of the energy budget, and find that the fraction of input power deposited into the ISM (the AGN coupling constant) is of order of a few percent during the first few Myr. This is in broad agreement with galaxy formation models employing AGN feedback. However, we find that in these early stages, this energy is deposited only in a small fraction (ISM volume. Finally we demonstrate the relevance of backflows ...

  16. TART97 a coupled neutron-photon 3-D, combinatorial geometry Monte Carlo transport code

    SciTech Connect

    Cullen, D.E.

    1997-11-22

    TART97 is a coupled neutron-photon, 3 Dimensional, combinatorial geometry, time dependent Monte Carlo transport code. This code can on any modern computer. It is a complete system to assist you with input preparation, running Monte Carlo calculations, and analysis of output results. TART97 is also incredibly FAST; if you have used similar codes, you will be amazed at how fast this code is compared to other similar codes. Use of the entire system can save you a great deal of time and energy. TART97 is distributed on CD. This CD contains on- line documentation for all codes included in the system, the codes configured to run on a variety of computers, and many example problems that you can use to familiarize yourself with the system. TART97 completely supersedes all older versions of TART, and it is strongly recommended that users only use the most recent version of TART97 and its data riles.

  17. 3D inclusion trail geometry determination within individual porphyroblasts using reflected light optical microscopy of oriented blocks

    NASA Astrophysics Data System (ADS)

    Munro, Mark; Bowden, Douglas; Ord, Alison; Hobbs, Bruce

    2015-04-01

    It is vital to interpret porphyroblast microstructures accurately relative to both one another and to external matrix structures when using them to reconstruct the tectono-metamorphic evolution of orogenic terranes. Mis-interpretation may have profound implications for either the deformation component or the inferred metamorphic reactions resulting in erroneous Pressure-Temperature-time-Deformation (P-T-t-D) trajectories. A number of well-established approaches have been devised for measuring porphyroblast inclusion trails including pitch and strike measurement, 'FitPitch' best-fit plane assignment, and the radial asymmetry method. A long-standing limitation of these methods is that they generally permit only a single measurement to be extracted from each individual porphyroblast, and therefore provide mean 3D orientation data for an entire population. Alternatively, High-Resolution X-ray Computed Tomography (HRXCT) facilitates the imaging of 3D internal geometries within individuals. However, at present significant operating costs render it unviable for routine application to large numbers of samples required for extracting meaningful tectonic interpretations. Here, a new method is presented for the determination of 3D geometries within porphyroblasts using reflected light examination of polished schist material. Reflected light microscopy yields good quality representation of inclusion trails preserved within porphyroblasts. Sectioning oriented samples into small, oriented blocks allows multiple intersections through porphyroblasts (generally >5mm) to be measured via mechanical stage and amalgamated to reconstruct the plane in 3D. The method represents an accessible alternative to HRXCT, which is applicable to any porphyroblastic phase of adequate size to permit at least two intersections. The technique is demonstrated on garnets from the Mesoproterozoic Mount Barren Group, southern Albany-Fraser orogen of S. W. Australia. Porphyroblasts within a structural domain of the Kybalup Schist member of the Mount Barren Group preserve two generations of foliation that have been largely overprinted in the matrix during the effects of subsequent deformation. The earliest generation (S1) was associated with approximately East-West oriented horizontal bulk shortening.

  18. 3D features of delayed thermal convection in fault zones: consequences for deep fluid processes in the Tiberias Basin, Jordan Rift Valley

    NASA Astrophysics Data System (ADS)

    Magri, Fabien; Möller, Sebastian; Inbar, Nimrod; Siebert, Christian; Möller, Peter; Rosenthal, Eliyahu; Kühn, Michael

    2015-04-01

    It has been shown that thermal convection in faults can also occur for subcritical Rayleigh conditions. This type of convection develops after a certain period and is referred to as "delayed convection" (Murphy, 1979). The delay in the onset is due to the heat exchange between the damage zone and the surrounding units that adds a thermal buffer along the fault walls. Few numerical studies investigated delayed thermal convection in fractured zones, despite it has the potential to transport energy and minerals over large spatial scales (Tournier, 2000). Here 3D numerical simulations of thermally driven flow in faults are presented in order to investigate the impact of delayed convection on deep fluid processes at basin-scale. The Tiberias Basin (TB), in the Jordan Rift Valley, serves as study area. The TB is characterized by upsurge of deep-seated hot waters along the faulted shores of Lake Tiberias and high temperature gradient that can locally reach 46 °C/km, as in the Lower Yarmouk Gorge (LYG). 3D simulations show that buoyant flow ascend in permeable faults which hydraulic conductivity is estimated to vary between 30 m/yr and 140 m/yr. Delayed convection starts respectively at 46 and 200 kyrs and generate temperature anomalies in agreement with observations. It turned out that delayed convective cells are transient. Cellular patterns that initially develop in permeable units surrounding the faults can trigger convection also within the fault plane. The combination of these two convective modes lead to helicoidal-like flow patterns. This complex flow can explain the location of springs along different fault traces of the TB. Besides being of importance for understanding the hydrogeological processes of the TB (Magri et al., 2015), the presented simulations provide a scenario illustrating fault-induced 3D cells that could develop in any geothermal system. References Magri, F., Inbar, N., Siebert, C., Rosenthal, E., Guttman, J., Möller, P., 2015. Transient simulations of large-scale hydrogeological processes causing temperature and salinity anomalies in the Tiberias Basin. Journal of Hydrology, 520(0), 342-355. Murphy, H.D., 1979. Convective instabilities in vertical fractures and faults. Journal of Geophysical Research: Solid Earth, 84(B11), 6121-6130. Tournier, C., Genthon, P., Rabinowicz, M., 2000. The onset of natural convection in vertical fault planes: consequences for the thermal regime in crystalline basementsand for heat recovery experiments. Geophysical Journal International, 140(3), 500-508.

  19. On the Effects of Non-Planar Fault Geometry on Strong Ground Motion

    NASA Astrophysics Data System (ADS)

    Olsen, K. B.; Aochi, H.

    2002-12-01

    We quantify the effects of complex fault geometry on low-frequency (<1 Hz) strong ground motion using numerical modeling of dynamic rupture. Our tests include the computation of synthetic seismograms for several simple rupture scenarios with planar and curved fault approximations of the 1994 Northridge and the 1992 Landers earthquakes. We use the boundary integral equation method (BIEM) to compute the dynamic rupture process, which includes the normal stress effects along the curved fault geometries. The wave propagation and computation of synthetic seismograms are modeled using a fourth-order finite-difference method (FDM). The near-field ground motion is significantly affected by the acceleration, deceleration and arrest of rupture due to fault bending, as well as the the variation in directivity of the rupture. We compare 1-Hz near-fault peak velocities for 40o-dipping, thrust faults buried 5 km with dimensions 24 km by 16 km. Compared to that for a planar fault, such as most approximations of the Northridge earthquake, a 6-km-long hanging-wall or footwall splay with a maximum offset of 1 km can change peak velocities by up to a factor of 2-3 above the fault. This change is caused in part by a variation in directivity, in part by differences in the rupture dynamics for the scenarios. In particular, the curved faults cause a gradual arrest of rupture, while the planar fault rupture stops abruptly with a resulting increase in moment. Our tests suggest that the differences in waveform are larger on the hanging wall compared to those on the footwall. The results imply that kinematic ground motion estimates and slip inversion may be significantly biased by the omission of dynamic rupture effects and of relatively gentle variation in fault geometry, even for long-period waves.

  20. Results of 3-D georadar surveying and trenching: the San Andreas fault near its northern landward limit

    NASA Astrophysics Data System (ADS)

    Green, A.; Gross, R.; Holliger, K.; Horstmeyer, H.; Baldwin, J.

    2003-04-01

    As part of a program to determine the location and geometry of the San Andreas Fault (SAF) buried beneath shallow sediments near its northern landward limit, three >20 m long parallel trenches were constructed at positions distributed over a distance of ˜55 m. The majority of excavated material comprised unconsolidated fluvial sediments deposited in a number of paleochannels. Single zones of active faulting identified in each of the trenches were initially interpreted in terms of a solitary strand of the SAF. To map the SAF between and beyond the trenches and to detect other active fault zones hidden by the young sedimentary cover, we collected a dense ground-penetrating radar (georadar) data set across a 23.2 x 72 m area. The data were recorded using a semi-automated acquisition system that included a conventional georadar unit coupled to a self-tracking laser theodolite with automatic target recognition capabilities. Since these data were plagued by system ringing as a result of the moderate- to high-electrical conductivities of the surficial sediments, an extensive data processing scheme was required to extract meaningful subsurface information. The final processed georadar volume (cuboid) contained numerous subhorizontal and trough-shaped reflections that originated from the fluvial paleochannels. Using the geological interpretation of the trench walls as a guide to pick semi-automatically the times of the most important reflecting horizons, we discovered that alignments of the nearly linear boundaries of these horizons defined two NW-SE trending strands of the SAF within the survey area. The georadar expression of the eastern SAF strand could only be traced over a distance of ˜38 m. It had been intersected in the northern trench. In contrast, the western SAF strand extended over the entire length of the georadar volume and had been intersected in the central and southern trenches. Prominent reflections on georadar cross-sections were found to be vertically displaced by 0.2 0.3 m across both SAF strands. A conspicuous linear-trending feature observed on horizontal sections at 3.3 3.6 m depth was laterally offset by 4.5 5.5 m along the eastern SAF strand. The interpreted vertical and horizontal offsets could have been generated by the 1906 San Francisco earthquake and/or earlier events. Undetermined amounts of aseismic slip may also have occurred along the newly defined SAF strands.

  1. Results of 3-D georadar surveying and trenching the San Andreas fault near its northern landward limit

    NASA Astrophysics Data System (ADS)

    Green, Alan; Gross, Ralf; Holliger, Klaus; Horstmeyer, Heinrich; Baldwin, John

    2003-06-01

    As part of a program to determine the location and geometry of the San Andreas Fault (SAF) buried beneath shallow sediments near its northern landward limit, three >20-m-long parallel trenches were constructed at positions distributed over a distance of ˜55 m. The majority of excavated material comprised unconsolidated fluvial sediments deposited in a number of paleochannels. Single zones of active faulting identified in each of the trenches were initially interpreted in terms of a solitary strand of the SAF. To map the SAF between and beyond the trenches and to detect other active fault zones hidden by the young sedimentary cover, we collected a dense ground-penetrating radar (georadar) data set across a 23.2×72 m area. The data were recorded using a semi-automated acquisition system that included a conventional georadar unit coupled to a self-tracking laser theodolite with automatic target recognition capabilities. Since these data were plagued by system ringing as a result of the moderate-to-high electrical conductivities of the surficial sediments, an extensive data processing scheme was required to extract meaningful subsurface information. The final processed georadar volume (cuboid) contained numerous subhorizontal and trough-shaped reflections that originated from the fluvial paleochannels. Using the geological interpretation of the trench walls as a guide to pick semi-automatically the times of the most important reflecting horizons, we discovered that alignments of the nearly linear boundaries of these horizons defined two NW-SE trending strands of the SAF within the survey area. The georadar expression of the eastern SAF strand could only be traced over a distance of ˜38 m. It had been intersected in the northern trench. In contrast, the western SAF strand extended over the entire length of the georadar volume and had been intersected in the central and southern trenches. Prominent reflections on georadar cross sections were found to be vertically displaced by 0.2-0.3 m across both SAF strands. A conspicuous linear-trending feature observed on horizontal sections at 3.3-3.6 m depth was laterally offset by 4.5-5.5 m along the eastern SAF strand. The interpreted vertical and horizontal offsets could have been generated by the 1906 San Francisco earthquake and/or earlier events. Undetermined amounts of aseismic slip may also have occurred along the newly defined SAF strands.

  2. A Coupled Neutron-Photon 3-D Combinatorial Geometry Monte Carlo Transport Code

    Energy Science and Technology Software Center (ESTSC)

    1998-06-12

    TART97 is a coupled neutron-photon, 3 dimensional, combinatorial geometry, time dependent Monte Carlo transport code. This code can run on any modern computer. It is a complete system to assist you with input preparation, running Monte Carlo calculations, and analysis of output results. TART97 is also incredibly fast: if you have used similar codes, you will be amazed at how fast this code is compared to other similar codes. Use of the entire system canmore »save you a great deal of time and energy. TART 97 is distributed on CD. This CD contains on-line documentation for all codes included in the system, the codes configured to run on a variety of computers, and many example problems that you can use to familiarize yourself with the system. TART97 completely supersedes all older versions of TART, and it is strongly recommended that users only use the most recent version of TART97 and ist data files.« less

  3. Validation and Analysis of Forward Osmosis CFD Model in Complex 3D Geometries

    PubMed Central

    Gruber, Mathias F.; Johnson, Carl J.; Tang, Chuyang; Jensen, Mogens H.; Yde, Lars; Hélix-Nielsen, Claus

    2012-01-01

    In forward osmosis (FO), an osmotic pressure gradient generated across a semi-permeable membrane is used to generate water transport from a dilute feed solution into a concentrated draw solution. This principle has shown great promise in the areas of water purification, wastewater treatment, seawater desalination and power generation. To ease optimization and increase understanding of membrane systems, it is desirable to have a comprehensive model that allows for easy investigation of all the major parameters in the separation process. Here we present experimental validation of a computational fluid dynamics (CFD) model developed to simulate FO experiments with asymmetric membranes. Simulations are compared with experimental results obtained from using two distinctly different complex three-dimensional membrane chambers. It is found that the CFD model accurately describes the solute separation process and water permeation through membranes under various flow conditions. It is furthermore demonstrated how the CFD model can be used to optimize membrane geometry in such as way as to promote the mass transfer. PMID:24958428

  4. Validation and Analysis of Forward Osmosis CFD Model in Complex 3D Geometries.

    PubMed

    Gruber, Mathias F; Johnson, Carl J; Tang, Chuyang; Jensen, Mogens H; Yde, Lars; Hélix-Nielsen, Claus

    2012-01-01

    In forward osmosis (FO), an osmotic pressure gradient generated across a semi-permeable membrane is used to generate water transport from a dilute feed solution into a concentrated draw solution. This principle has shown great promise in the areas of water purification, wastewater treatment, seawater desalination and power generation. To ease optimization and increase understanding of membrane systems, it is desirable to have a comprehensive model that allows for easy investigation of all the major parameters in the separation process. Here we present experimental validation of a computational fluid dynamics (CFD) model developed to simulate FO experiments with asymmetric membranes. Simulations are compared with experimental results obtained from using two distinctly different complex three-dimensional membrane chambers. It is found that the CFD model accurately describes the solute separation process and water permeation through membranes under various flow conditions. It is furthermore demonstrated how the CFD model can be used to optimize membrane geometry in such as way as to promote the mass transfer. PMID:24958428

  5. DIF3D nodal neutronics option for two- and three-dimensional diffusion theory calculations in hexagonal geometry. [LMFBR

    SciTech Connect

    Lawrence, R.D.

    1983-03-01

    A nodal method is developed for the solution of the neutron-diffusion equation in two- and three-dimensional hexagonal geometries. The nodal scheme has been incorporated as an option in the finite-difference diffusion-theory code DIF3D, and is intended for use in the analysis of current LMFBR designs. The nodal equations are derived using higher-order polynomial approximations to the spatial dependence of the flux within the hexagonal-z node. The final equations, which are cast in the form of inhomogeneous response-matrix equations for each energy group, involved spatial moments of the node-interior flux distribution plus surface-averaged partial currents across the faces of the node. These equations are solved using a conventional fission-source iteration accelerated by coarse-mesh rebalance and asymptotic source extrapolation. This report describes the mathematical development and numerical solution of the nodal equations, as well as the use of the nodal option and details concerning its programming structure. This latter information is intended to supplement the information provided in the separate documentation of the DIF3D code.

  6. Effects of 3D Geometries on Cellular Gradient Sensing and Polarization

    E-print Network

    Fabian Spill; Vivi Andasari; Michael Mak; Roger D. Kamm; Muhammad H. Zaman

    2015-08-12

    During cell migration, cells become polarized, change their shape, and move in response to various cues, both internal and external. Many existing mathematical models of cell polarization are formulated in one or two spatial dimensions and hence cannot accurately capture the effect of cell shape, as well as the response of the cell to signals from different directions in a three-dimensional environment. To study those effects, we introduce a three-dimensional reaction-diffusion model of a cell. As some key molecules in cell polarization, such as the small GTPases, can exist both membrane bound and soluble in the cytosol, we first look at the role of cell geometry on the membrane binding/unbinding dynamics of such molecules. We derive quite general conditions under which effective existing one or two-dimensional computational models are valid, and find novel renormalizations of parameters in the effective model. We then extend an established one-dimensional cell polarization pathway in our three-dimensional framework. Our simulations indicate that even in some quasi-one-dimensional scenarios, such as polarization of a cell along a linear growth factor gradient, the cell shape can influence the polarization behavior of the cell, with cells of some shape polarizing more efficiently than those of other shapes. We also investigate the role of the previously ignored membrane unbinding rate on polarization. Furthermore, we simulate the response of the cell when the external signal is changing directions, and we find that more symmetric cells can change their polarized state more effectively towards the new stimulus than cells which are elongated along the direction of the original stimulus.

  7. San Andreas fault geometry in the Parkfield, California, region

    USGS Publications Warehouse

    Simpson, R.W.; Barall, M.; Langbein, J.; Murray, J.R.; Rymer, M.J.

    2006-01-01

    In map view, aftershocks of the 2004 Parkfield earthquake lie along a line that forms a straighter connection between San Andreas fault segments north and south of the Parkfield reach than does the mapped trace of the fault itself. A straightedge laid on a geologic map of Central California reveals a ???50-km-long asymmetric northeastward warp in the Parkfield reach of the fault. The warp tapers gradually as it joins the straight, creeping segment of the San Andreas to the north-west, but bends abruptly across Cholame Valley at its southeast end to join the straight, locked segment that last ruptured in 1857. We speculate that the San Andreas fault surface near Parkfield has been deflected in its upper ???6 km by nonelastic behavior of upper crustal rock units. These units and the fault surface itself are warped during periods between large 1857-type earthquakes by the presence of the 1857-locked segment to the south, which buttresses intermittent coseismic and continuous aseismic slip on the Parkfield reach. Because of nonelastic behavior, the warping is not completely undone when an 1857-type event occurs, and the upper portion of the three-dimensional fault surface is slowly ratcheted into an increasingly prominent bulge. Ultimately, the fault surface probably becomes too deformed for strike-slip motion, and a new, more vertical connection to the Earth's surface takes over, perhaps along the Southwest Fracture Zone. When this happens a wedge of material currently west of the main trace will be stranded on the east side of the new main trace.

  8. Density structure and geometry of the Costa Rican subduction zone from 3-D gravity modeling and local earthquake data

    NASA Astrophysics Data System (ADS)

    Lücke, O. H.; Arroyo, I. G.

    2015-10-01

    The eastern part of the oceanic Cocos Plate presents a heterogeneous crustal structure due to diverse origins and ages as well as plate-hot spot interactions which originated the Cocos Ridge, a structure that converges with the Caribbean Plate in southeastern Costa Rica. The complex structure of the oceanic plate directly influences the dynamics and geometry of the subduction zone along the Middle American Trench. In this paper an integrated interpretation of the slab geometry in Costa Rica is presented based on 3-D density modeling of combined satellite and surface gravity data, constrained by available geophysical and geological data and seismological information obtained from local networks. The results show the continuation of steep subduction geometry from the Nicaraguan margin into northwestern Costa Rica, followed by a moderate dipping slab under the Central Cordillera toward the end of the Central American Volcanic Arc. Contrary to commonly assumed, to the southeast end of the volcanic arc, our preferred model shows a steep, coherent slab that extends up to the landward projection of the Panama Fracture Zone. Overall, a gradual change in the depth of the intraplate seismicity is observed, reaching 220 km in the northwestern part, and becoming progressively shallower toward the southeast, where it reaches a maximum depth of 75 km. The changes in the terminal depth of the observed seismicity correlate with the increased density in the modeled slab. The absence of intermediate depth (> 75 km) intraplate seismicity in the southeastern section and the higher densities for the subducted slab in this area, support a model in which dehydration reactions in the subducted slab cease at a shallower depth, originating an anhydrous and thus aseismic slab.

  9. Exploration of Wadi Zerka Ma'in rotational fault and its drainage pattern, Eastern of Dead Sea, by means of remote sensing, GIS and 3D geological modeling

    NASA Astrophysics Data System (ADS)

    Odeh, Taleb; Gloaguen, Richard; Schirmer, Mario; Geyer, Stefan; Rödiger, Tino; Siebert, Christian

    2009-09-01

    The Wadi Zerka Ma'in catchment area is located in the North East of the Dead Sea. It contains a confined river of about 23 km length. The region is characterized by a recent sharp base level drop and a strong orographic control on climatic parameters such as temperature and precipitation. It is controlled by three regional structural systems as follow: 1) the anticline - syncline system (late Cretaceous - end of Miocene) which is a part of Syrian fold arc system; 2) NW - SE faults system which were generated simultaneously and parallel to the Red Sea spreading; 3) NWW - SSE faults system which are perpendicular to the Dead Sea and younger than the Red Sea fault system; 4) NNW - SSE faults system (middle Miocene - until now) which were generated simultaneously and parallel to the active Dead Sea transform fault. The structural setting of the study area was evaluated by means of a three-dimensional (3D) geological model, a digital elevation model (DEM) with resolutions 15 meters and stream profile analysis. DEM generation was performed using ASTER data. We found that the Wadi is located at the junction of two main fault systems. The major feature is a trans-tensional fault displacement which changes from 0 to 200 m. We showed that the catchment area is a result of a rotational fault while the river changes its flow direction according to the different fault system directions. The lower portion of the basin is affected by the major base level drops and display contributing rivers in exceptional non-equilibrium. Thus this catchment allows observing the rapid adaptation of the drainage system to both climatic and tectonic forcing.

  10. Geometry and architecture of faults in a syn-rift normal fault array: The Nukhul half-graben, Suez rift, Egypt

    NASA Astrophysics Data System (ADS)

    Wilson, Paul; Gawthorpe, Rob L.; Hodgetts, David; Rarity, Franklin; Sharp, Ian R.

    2009-08-01

    The geometry and architecture of a well exposed syn-rift normal fault array in the Suez rift is examined. At pre-rift level, the Nukhul fault consists of a single zone of intense deformation up to 10 m wide, with a significant monocline in the hanging wall and much more limited folding in the footwall. At syn-rift level, the fault zone is characterised by a single discrete fault zone less than 2 m wide, with damage zone faults up to approximately 200 m into the hanging wall, and with no significant monocline developed. The evolution of the fault from a buried structure with associated fault-propagation folding, to a surface-breaking structure with associated surface faulting, has led to enhanced bedding-parallel slip at lower levels that is absent at higher levels. Strain is enhanced at breached relay ramps and bends inherited from pre-existing structures that were reactivated during rifting. Damage zone faults observed within the pre-rift show ramp-flat geometries associated with contrast in competency of the layers cut and commonly contain zones of scaly shale or clay smear. Damage zone faults within the syn-rift are commonly very straight, and may be discrete fault planes with no visible fault rock at the scale of observation, or contain relatively thin and simple zones of scaly shale or gouge. The geometric and architectural evolution of the fault array is interpreted to be the result of (i) the evolution from distributed trishear deformation during upward propagation of buried fault tips to surface faulting after faults breach the surface; (ii) differences in deformation response between lithified pre-rift units that display high competence contrasts during deformation, and unlithified syn-rift units that display low competence contrasts during deformation, and; (iii) the history of segmentation, growth and linkage of the faults that make up the fault array. This has important implications for fluid flow in fault zones.

  11. Geometry and Kinematics of the Lopukangri Fault System: Implications for Internal Deformation of the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Murphy, M. A.; Taylor, M. H.

    2006-12-01

    We present geologic mapping and structural data from the Lopukangri fault system in south-central Tibet that sheds light on the geometry, kinematics and spatial characteristics of deformation in western Tibet and the western Himalaya. The Lopukangri fault system strikes N09E and extends 150 km from the Lhasa terrane into the Tethyan fold-thrust belt at 84.5° N. Geologic mapping shows that the deformation is accommodated by a northwest dipping oblique fault system, which accommodates both right-lateral and normal dip-slip movement, consistent with right-lateral separations of Quaternary surficial deposits. The fault system juxtaposes amphibolite-grade rocks in its footwall against greenschist-grade rocks in its hanging wall. Deformation is distributed over a 4 km wide zone that predominately records right-lateral normal slip in ductile and brittle shear fabrics. The fault system right-laterally separates the Gangdese batholith, Kailas conglomerate, Great Counter thrust, and the Tethyan fold-thrust belt for 15 km. Age estimates of the Kailas conglomerate in the Kailas region implies that the Lopukangri fault system initiated after the Early Miocene( 23Ma). The observation that the Lopukangri fault system cuts the Indus-Yaly suture zone, rules out active strike-slip faulting along it at this locality. To assess the role of the Lopukangri fault system in accommodating strain within western Tibet, we compare our results with fault-slip data and structural geometries from the Karakoram and Dangardzong (Thakkhola graben) fault systems. The Dangardzong fault shares similar kinematics with the Lopukangri fault system, both display a significant component of right-slip. Although the two faults do not strike into one another, they may be linked via a transfer zone. The Karakoram fault accommodates right-lateral slip in which a portion of the total slip extends from the Tibetan plateau into the Himalayan thrust belt via right-stepover structures. Fault slip data from the Karakoram fault between 32°N to 30°N shows that its slip direction swings to more easterly orientations from north to south, paralleling the trace of the Himalayan thrust belt. We present a preliminary kinematic model to explain the fault slip data and regional geometry of these fault systems that incorporates eastward translation and counterclockwise rotation of a semi-triangular-shaped block. The Karakoram fault, the Dangardzong-Lopukangri fault system, and the Awong Co fault represent the major block boundaries. Although there is internal deformation within the block, inspection of satellite imagery and geologic maps suggests it is minor. We hypothesize that this strain pattern results from radial expansion of the Himalayan arc that causes regions within it to undergo arc-parallel stretching as well as arc-normal shortening. In this scenario rotation facilitates arc-normal shortening and arc-parallel stretching between south- western Tibetan plateau and Himalayan fold-thrust belt.

  12. Silicon Solar Cells: High-Performance and Omnidirectional Thin-Film Amorphous Silicon Solar Cell Modules Achieved by 3D Geometry Design (Adv. Mater. 42/2015).

    PubMed

    Yu, Dongliang; Yin, Min; Lu, Linfeng; Zhang, Hanzhong; Chen, Xiaoyuan; Zhu, Xufei; Che, Jianfei; Li, Dongdong

    2015-11-01

    High-performance thin-film hydrogenated amorphous silicon solar cells are achieved by combining macroscale 3D tubular substrates and nanoscale 3D cone-like antireflective films, as described on page 6747 by D. Li and co-workers. The tubular geometry delivers a series of advantages for the large-scale deployment of photovoltaics, such as omnidirectional performance, easier encapsulation, decreased wind resistance, and easy integration with a second device inside the glass tube. PMID:26545182

  13. Fault geometries on Uranus' satellite Miranda: Implications for internal structure and heat flow

    NASA Astrophysics Data System (ADS)

    Beddingfield, C. B.; Burr, D. M.; Emery, J. P.

    2015-02-01

    Miranda, a ?470-km-diameter uranian icy satellite, has a surface that exhibits evidence of a complex tectonic history. Tectonic structures are mostly localized in three regions termed coronae, but also form a rift system inferred to be global in extent. Ridges within the boundary of Arden Corona, and those that make up the 340° Chasma, part of the global rift system, have been interpreted as normal fault blocks. Using Voyager data, we test the hypothesis that these Arden Corona faults, as well as those at the northern edge of the 340° Chasma, are listric in geometry. For this testing, we use four geometric criteria for listric faults: (1) progressive down-dip decrease in fault scarp dip, (2) progressive down-dip increase in back-tilted face slope, (3) concavity of the exposed scarp surface, and (4) presence of a rollover structure. Results of this analysis support the hypothesis that the faults within the Arden Corona boundary are listric in geometry, but do not strongly support the hypothesis for the faults within the 340° Chasma. By analogy with terrestrial structures, the listric character of faults within the Arden Corona boundary suggests the presence of a subsurface detachment. This detachment likely occurred at Miranda's brittle-ductile transition zone at the time of faulting. Measurements of the Arden Corona fault system geometry are used to estimate depths to the proposed brittle-ductile transition zone at the time of faulting, resulting in values of 6.7-9.0 km. Those depths in turn are used to estimate a thermal gradient of 6-25 K km-1 and a surface heat flux of 31-112 mW m-2. The weaker evidence of a listric geometry for the faults of the 340° Chasma suggests that those faults did not interact with a brittle-ductile transition at the time of their formation. Our estimated thermal gradient of the Arden Corona region is consistent with a previous heating event on Miranda that was as significant as Europa's current resonance-induced tidal heating. This heating event may be associated with a hypothesized previous tidal resonance of Miranda with Umbriel and/or Ariel.

  14. Control of fault geometry and permeability contrast on fault-related hydrothermal fluid flow

    NASA Astrophysics Data System (ADS)

    Andersen, Christine; Rüpke, Lars; Hasenclever, Jörg; Grevemeyer, Ingo; Petersen, Sven

    2015-04-01

    High-temperature black smoker systems along slow-spreading ridges such as the Mid-Atlantic Ridge (MAR) are frequently related to tectonic fault zones and therefore are commonly found off axis. While preferential flow of hot fluids along highly permeable, fractured rocks seems intuitive, such efficient flow leads to the entrainment of cold ambient seawater resulting in a drastic decrease in vent temperatures. This temperature drop is difficult to reconcile with high-temperature black smoker activity observed at outcropping fault zones. In our recent study we aim to resolve this apparent contradiction by combining newly acquired seismological data (Grevemeyer et al., 2013) from the high-temperature, off-axis Logatchev 1 hydrothermal field (LHF1) along the MAR with 2D hydrothermal flow modeling. The seismic data shows intense off-axis seismicity with focal mechanisms suggesting a fault zone dipping from LHF1 toward the ridge axis. In order to explain fault-related high-temperature hydrothermal discharge as observed at LHF1, our simulations predict that fault zones need to be just permeable and wide enough to capture and redirect hydrothermal plumes rising from depth but, because they are not isolated conduits, must not be too wide or permeable in order to prevent cooling through mixing with ambient colder fluids. The two controlling parameters fault width and permeability contrast between fault and surrounding rock can be expressed as a single term, the relative transmissibility of the fault zone, which is defined by the product of the two. Low relative fault transmissibility leads to plumes that cross the fault and vent above the heat source rather than at the fault termination at the seafloor. High relative fault transmissibility leads to significantly lower vent exit temperatures than those observed at black smoker systems. Our findings further illustrate the intrinsic relationship between permeability, mass flux and upflow temperature: the higher the permeability, the higher the mass flux and the lower the vent temperature. The common occurrence of fault-linked high-temperature vent fields strongly points at a not-yet-quantified self-adjusting permeability that depends on pore space-clogging reactions between hydrothermal and ambient cold fluids. Furthermore, the temperature drop associated with any high permeability zone in heterogeneous crust may well explain the sparse high-temperature vent fields along the MAR and why the heterogeneous crust of the Atlantic, with its strong permeability contrasts, is predominantly cooled by lower-temperature fluid flow.

  15. Thrust geometries in unconsolidated Quaternary sediments around the Eupchon fault, SE Korea

    NASA Astrophysics Data System (ADS)

    Park, J. Y.; Kim, Y.-S.; Kim, J. H.; Shin, H. C.

    2003-04-01

    It had been considered that Korean Peninsula is located in a relatively stable continental platform. Over ten Quaternary faults have recently been discovered, however, in the south-eastern part of the Korean Peninsula. The Eupchon Fault was discovered at the construction site of a primary school, close to a nuclear power plant. In order to understand the characteristics of the Eupchon fault, we carried out two trench surveys near the first finding site. The orientations of trench sites are 150o and 170o, the widths are 1.3 m and 1.5 m, and the maximum depths are 2.8 m and 5.5 m, respectively. The trenches are in Quaternary unconsolidated marine terrace sediments, which have horizontal bedding planes, are well sorted, and range from pebbles to muds The fault system includes one main reverse fault (N20o E/40o SE) with about 4m displacement and a series of branches. Structures in the fault system include synthetic and antithetic faults, hanging wall anticlines, drag folds, back thrusts, pop-up structures, flat-ramp geometries and duplexes, i.e. very similar to thrust systems in consolidated rocks. In the upper part of the fault system, several tip damage zone patterns are observed, indicating that the fault system terminates in the upper part of the section. Pebbles along the main fault plane show preferred orientation of long axes indicating the fault trace. The orientation of the slickenside striea is E-W, indicating the movement direction. The unconformity between the Quaternary deposits and the underlying Tertiary andesites and Cretaceous sedimentary rocks is displaced in a reverse sense. A normal displacement was reported lower in the section, indicating the fault had a normal displacement and was reverse reactivated during the Quaternary.

  16. 3D Geometrical Inspection of Complex Geometry Parts Using a Novel Laser Triangulation Sensor and a Robot

    PubMed Central

    Brosed, Francisco Javier; Aguilar, Juan José; Guillomía, David; Santolaria, Jorge

    2011-01-01

    This article discusses different non contact 3D measuring strategies and presents a model for measuring complex geometry parts, manipulated through a robot arm, using a novel vision system consisting of a laser triangulation sensor and a motorized linear stage. First, the geometric model incorporating an automatic simple module for long term stability improvement will be outlined in the article. The new method used in the automatic module allows the sensor set up, including the motorized linear stage, for the scanning avoiding external measurement devices. In the measurement model the robot is just a positioning of parts with high repeatability. Its position and orientation data are not used for the measurement and therefore it is not directly “coupled” as an active component in the model. The function of the robot is to present the various surfaces of the workpiece along the measurement range of the vision system, which is responsible for the measurement. Thus, the whole system is not affected by the robot own errors following a trajectory, except those due to the lack of static repeatability. For the indirect link between the vision system and the robot, the original model developed needs only one first piece measuring as a “zero” or master piece, known by its accurate measurement using, for example, a Coordinate Measurement Machine. The strategy proposed presents a different approach to traditional laser triangulation systems on board the robot in order to improve the measurement accuracy, and several important cues for self-recalibration are explored using only a master piece. Experimental results are also presented to demonstrate the technique and the final 3D measurement accuracy. PMID:22346569

  17. 3D Dynamic Rupture Simulation Across a Complex Fault System: the Mw7.0, 2010, Haiti Earthquake

    NASA Astrophysics Data System (ADS)

    Douilly, R.; Aochi, H.; Calais, E.; Freed, A. M.

    2013-12-01

    Earthquakes ruptures sometimes take place on a secondary fault and surprisingly do not activate an adjacent major one. The 1989 Loma Prieta earthquake is a classic case where rupture occurred on a blind thrust while the adjacent San Andreas Fault was not triggered during the process. Similar to Loma Prieta, the Mw7.0, January 12 2010, Haiti earthquake also ruptured a secondary blind thrust, the Léogâne fault, adjacent to the main plate boundary, the Enriquillo Plantain Garden Fault, which did not rupture during this event. Aftershock relocalizations delineate the Léogâne rupture with two north dipping segments with slightly different dip, where the easternmost segment had mostly dip-slip motion and the westernmost one had mostly strike-slip motion. In addition, an offshore south dipping structure inferred from the aftershocks to the west of the rupture zone coincides with the offshore Trois Baies reverse fault, a region of increase in Coulomb stress increase. In this study, we investigate the rupture dynamics of the Haiti earthquake in a complex fault system of multiple segments identified by the aftershock relocations. We suppose a background stress regime that is consistent with the type of motion of each fault and with the regional tectonic regime. We initiate a nucleation on the east segment of the Léogâne fault by defining a circular region with a 2 km radius where shear stress is slightly greater than the yield stress. By varying friction on faults and background stress, we find a range of plausible scenarios. In the absence of near-field seismic records of the event, we score the different models against the static deformation field derived from GPS and InSAR at the surface. All the plausible simulations show that the rupture propagates from the eastern to the western segment along the Léogâne fault, but not on the Enriquillo fault nor on the Trois Baies fault. The best-fit simulation shows a significant increase of shear stresses on the Trois Baies fault, which might explain observed triggered aftershocks on this fault and small increase of shear stresses on the Enriquillo fault. We also find that a shift to north of about 3 km of the western segment of the Léogâne fault from recent studies provides a better fit to the coseismic InSAR and GPS displacements.

  18. Comparative geometry of the San Andreas Fault, California, and laboratory fault zones

    USGS Publications Warehouse

    Moore, Diane E.; Byerlee, J.D.

    1991-01-01

    Textural examination of fault gouge deformed in triaxial friction experiments has revealed differences in the orientations of secondary shear sets between the stably sliding and stick-slip samples. In order to determine whether such differences can be identified in natural faults, maps of recently active breaks along the San Andreas fault were examined to compare the types and orientations of secondary structures mapped in the creeping and locked sections. The fault zone was divided into 52 geometrically defined segments of uniform strike, which were then grouped into 7 sections: 4 straight and two curved sections, and Cholame Valley. Many of the gross geometric characteristics of the individual segments, such as length, width, and stepover size, reflect their position in either a straight or a curved section. In contrast, with respect to the orientations of the recent breaks within the segments, the single creeping section differs from all of the locked sections, both straight and curved. -from Authors

  19. 3D Temperature distribution and numerical modeling of heat transfers in an active fault zone: Eugene Island 330, Offshore Louisiana.

    E-print Network

    Guerin, Gilles

    fault zone: Eugene Island 330, Offshore Louisiana. 4.1 Abstract At the center of an active growth fault system underlain by high-relief salt diapirs, the Eugene Island 330 field is a case study productive reservoirs of the EI330 oil field. #12;126 4.2 Introduction The Eugene Island 330 (EI330) oil

  20. Vectorization of a 2D-1D Iterative Algorithm for the 3D Neutron Transport Problem in Prismatic Geometries

    NASA Astrophysics Data System (ADS)

    Moustafa, Salli; Févotte, François; Lathuilière, Bruno; Plagne, Laurent

    2014-06-01

    The past few years have been marked by a noticeable increase in the interest in 3D whole-core heterogeneous deterministic neutron transport solvers for reference calculations. Due to the extremely large problem sizes tackled by such solvers, they need to use adapted numerical methods and need to be efficiently implemented to take advantage of the full computing power of modern systems. As for numerical methods, one possible approach consists in iterating over resolutions of 2D and 1D MOC problems by taking advantage of prismatic geometries. The MICADO solver, developed at EDF R&D, is a parallel implementation of such a method in distributed and shared memory systems. However it is currently unable to use SIMD vectorization to leverage the full computing power of modern CPUs. In this paper, we describe our first effort to support vectorization in MICADO, typically targeting Intel© SSE CPUs. Both the 2D and 1D algorithms are vectorized, allowing for high expected speedups for the whole spatial solver. We present benchmark computations, which show nearly optimal speedups for our vectorized implementation on the TAKEDA case.

  1. Measurement of the 3D geometry of the fascial arches in women with a unilateral levator defect and “architectural distortion”

    PubMed Central

    LARSON, Kindra A.; LUO, Jiajia; YOUSUF, Aisha; ASHTON-MILLER, James A.; DeLANCEY, John O.L.

    2013-01-01

    Objective The arcus tendineus fascia pelvis (ATFP) and arcus tendineus levator ani (ATLA) are elements of anterior vaginal support. This study describes their geometry in women with unilateral levator ani muscle defects and associated “architectural distortion.” Study Design Fourteen subjects with unilateral defects underwent MRI. 3-D models of the arcus were generated. Locations of these relative to an ilial reference line were compared between unaffected and affected sides. Results Pronounced changes occurred on the defect sides’ ventral region. The furthest point of the ATLA lay up to a mean 10.2mm (p=0.01) more inferior and 6.5mm (p=0.02) more medial than that on the intact side. Similarly, the ATFP lay 6 mm (p=0.01*) more inferior than on the unaffected side. Conclusion The ventral arcus anatomy is significantly altered in the presence of levator defects and architectural distortion. Alterations of these key fixation points will change supportive force direction along the lateral anterior vaginal wall, increasing the risk for anterior vaginal wall prolapse. PMID:21818620

  2. The role of fault surface geometry in the evolution of the fault deformation zone: comparing modeling with field example from the Vignanotica normal fault (Gargano, Southern Italy).

    NASA Astrophysics Data System (ADS)

    Maggi, Matteo; Cianfarra, Paola; Salvini, Francesco

    2013-04-01

    Faults have a (brittle) deformation zone that can be described as the presence of two distintive zones: an internal Fault core (FC) and an external Fault Damage Zone (FDZ). The FC is characterized by grinding processes that comminute the rock grains to a final grain-size distribution characterized by the prevalence of smaller grains over larger, represented by high fractal dimensions (up to 3.4). On the other hand, the FDZ is characterized by a network of fracture sets with characteristic attitudes (i.e. Riedel cleavages). This deformation pattern has important consequences on rock permeability. FC often represents hydraulic barriers, while FDZ, with its fracture connection, represents zones of higher permability. The observation of faults revealed that dimension and characteristics of FC and FDZ varies both in intensity and dimensions along them. One of the controlling factor in FC and FDZ development is the fault plane geometry. By changing its attitude, fault plane geometry locally alter the stress component produced by the fault kinematics and its combination with the bulk boundary conditions (regional stress field, fluid pressure, rocks rheology) is responsible for the development of zones of higher and lower fracture intensity with variable extension along the fault planes. Furthermore, the displacement along faults provides a cumulative deformation pattern that varies through time. The modeling of the fault evolution through time (4D modeling) is therefore required to fully describe the fracturing and therefore permeability. In this presentation we show a methodology developed to predict distribution of fracture intensity integrating seismic data and numerical modeling. Fault geometry is carefully reconstructed by interpolating stick lines from interpreted seismic sections converted to depth. The modeling is based on a mixed numerical/analytical method. Fault surface is discretized into cells with their geometric and rheological characteristics. For each cell, the acting stress and strength are computed by analytical laws (Coulomb failure). Total brittle deformation for each cell is then computed by cumulating the brittle failure values along the path of each cell belonging to one side onto the facing one. The brittle failure value is provided by the DF function, that is the difference between the computed shear and the strength of the cell at each step along its path by using the Frap in-house developed software. The width of the FC and the FDZ are computed as a function of the DF distribution and displacement around the fault. This methodology has been successfully applied to model the brittle deformation pattern of the Vignanotica normal fault (Gargano, Southern Italy) where fracture intensity is expressed by the dimensionless H/S ratio representing the ratio between the dimension and the spacing of homologous fracture sets (i.e., group of parallel fractures that can be ascribed to the same event/stage/stress field).

  3. Testing 3D fault configuration in the northern Los Angeles basin, California via patterns of rock uplift the since 2.9 Ma

    NASA Astrophysics Data System (ADS)

    Cooke, M.; Meigs, A.; Marshall, S.

    2004-12-01

    Competing models of three-dimensional fault topology, starting from the Southern California Earthquake Center (SCEC) Community Fault Model (CFM), were tested for viability using numerical Boundary Element Method (BEM) models and patterns of rock uplift by folds in the northern Los Angeles basin Los Angeles basin. Thirteen structural cross-sections constrained by well and outcrop data were used to compile a structure contour map of the base of the Pico Formation (2.9 Ma) across about 50 km of the northern Los Angeles basin from the Coyote Hills on the east to Pacific Palisades on the west. A map of rock uplift rate was constructed from these data by measuring the structural relief relative to the central trough of the Los Angeles basin, a long-lived northwest-trending structural low that lies to the northeast of the Newport-Inglewood fault. BEM models of 3D fault topology were used to generate uplift rates over the same region using North-South contraction at 100 nanostrain/year. A suite of models investigate the sensitivity of uplift patterns to 1) dip of blind thrust faults (e.g. Las Cienegas and Elysian Park), 2) presence of low-angle (20 degree) thrust ramp below 10 km depths 3) regional extent of this low-angle ramp and 4) inclusion of near surface splays of the Santa Monica fault. Model-data compatibility was evaluated on the basis of structural trend, spatial variation in rates and location of major structures (i.e. key near surface folds). All models are consistent with the location and uplift pattern of the Coyote Hills and Santa Fe Springs structures, the location and orientation of the central trough, and a North-trending structure separating Santa Fe Springs on the east from Montebello to the northwest. Incorporation of the low-angle ramp below 10 km depth that is regionally extensive (i.e. many faults sole into this fault) improves model and geologic uplift compatibility. Furthermore, steepening the Las Cienegas and Elysian Park faults to 60 degrees reduces mismatch. If correct, our models are consistent with the emerging paradigms that 1) the north and northeastern boundaries of the Los Angeles basin's central trough are flanked by deep (> 10 km) and low-angle (<30 degree) fault ramps and 2) near surface thrust faults merge into this ramp with steep (60 degree) dips.

  4. The Development of WARP - A Framework for Continuous Energy Monte Carlo Neutron Transport in General 3D Geometries on GPUs

    NASA Astrophysics Data System (ADS)

    Bergmann, Ryan

    Graphics processing units, or GPUs, have gradually increased in computational power from the small, job-specific boards of the early 1990s to the programmable powerhouses of today. Compared to more common central processing units, or CPUs, GPUs have a higher aggregate memory bandwidth, much higher floating-point operations per second (FLOPS), and lower energy consumption per FLOP. Because one of the main obstacles in exascale computing is power consumption, many new supercomputing platforms are gaining much of their computational capacity by incorporating GPUs into their compute nodes. Since CPU-optimized parallel algorithms are not directly portable to GPU architectures (or at least not without losing substantial performance), transport codes need to be rewritten to execute efficiently on GPUs. Unless this is done, reactor simulations cannot take full advantage of these new supercomputers. WARP, which can stand for ``Weaving All the Random Particles,'' is a three-dimensional (3D) continuous energy Monte Carlo neutron transport code developed in this work as to efficiently implement a continuous energy Monte Carlo neutron transport algorithm on a GPU. WARP accelerates Monte Carlo simulations while preserving the benefits of using the Monte Carlo Method, namely, very few physical and geometrical simplifications. WARP is able to calculate multiplication factors, flux tallies, and fission source distributions for time-independent problems, and can run in both criticality or fixed source modes. WARP can transport neutrons in unrestricted arrangements of parallelepipeds, hexagonal prisms, cylinders, and spheres. WARP uses an event-based algorithm, but with some important differences. Moving data is expensive, so WARP uses a remapping vector of pointer/index pairs to direct GPU threads to the data they need to access. The remapping vector is sorted by reaction type after every transport iteration using a high-efficiency parallel radix sort, which serves to keep the reaction types as contiguous as possible and removes completed histories from the transport cycle. The sort reduces the amount of divergence in GPU ``thread blocks,'' keeps the SIMD units as full as possible, and eliminates using memory bandwidth to check if a neutron in the batch has been terminated or not. Using a remapping vector means the data access pattern is irregular, but this is mitigated by using large batch sizes where the GPU can effectively eliminate the high cost of irregular global memory access. WARP modifies the standard unionized energy grid implementation to reduce memory traffic. Instead of storing a matrix of pointers indexed by reaction type and energy, WARP stores three matrices. The first contains cross section values, the second contains pointers to angular distributions, and a third contains pointers to energy distributions. This linked list type of layout increases memory usage, but lowers the number of data loads that are needed to determine a reaction by eliminating a pointer load to find a cross section value. Optimized, high-performance GPU code libraries are also used by WARP wherever possible. The CUDA performance primitives (CUDPP) library is used to perform the parallel reductions, sorts and sums, the CURAND library is used to seed the linear congruential random number generators, and the OptiX ray tracing framework is used for geometry representation. OptiX is a highly-optimized library developed by NVIDIA that automatically builds hierarchical acceleration structures around user-input geometry so only surfaces along a ray line need to be queried in ray tracing. WARP also performs material and cell number queries with OptiX by using a point-in-polygon like algorithm. WARP has shown that GPUs are an effective platform for performing Monte Carlo neutron transport with continuous energy cross sections. Currently, WARP is the most detailed and feature-rich program in existence for performing continuous energy Monte Carlo neutron transport in general 3D geometries on GPUs, but compared to production codes like Serpent and MCNP, WARP ha

  5. Crustal structure and fault geometry of the 2010 Haiti earthquake from temporary seismometer deployments

    USGS Publications Warehouse

    Douilly, Roby; Haase, Jennifer S.; Ellsworth, William L.; Bouin, Marie?Paule; Calais, Eric; Symithe, Steeve J.; Armbruster, John G.; Mercier de Lépinay, Bernard; Deschamps, Anne; Mildor, Saint?Louis; Meremonte, Mark E.; Hough, Susan E.

    2013-01-01

    Haiti has been the locus of a number of large and damaging historical earthquakes. The recent 12 January 2010 Mw 7.0 earthquake affected cities that were largely unprepared, which resulted in tremendous losses. It was initially assumed that the earthquake ruptured the Enriquillo Plantain Garden fault (EPGF), a major active structure in southern Haiti, known from geodetic measurements and its geomorphic expression to be capable of producing M 7 or larger earthquakes. Global Positioning Systems (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data, however, showed that the event ruptured a previously unmapped fault, the Léogâne fault, a north?dipping oblique transpressional fault located immediately north of the EPGF. Following the earthquake, several groups installed temporary seismic stations to record aftershocks, including ocean?bottom seismometers on either side of the EPGF. We use data from the complete set of stations deployed after the event, on land and offshore, to relocate all aftershocks from 10 February to 24 June 2010, determine a 1D regional crustal velocity model, and calculate focal mechanisms. The aftershock locations from the combined dataset clearly delineate the Léogâne fault, with a geometry close to that inferred from geodetic data. Its strike and dip closely agree with the global centroid moment tensor solution of the mainshock but with a steeper dip than inferred from previous finite fault inversions. The aftershocks also delineate a structure with shallower southward dip offshore and to the west of the rupture zone, which could indicate triggered seismicity on the offshore Trois Baies reverse fault. We use first?motion focal mechanisms to clarify the relationship of the fault geometry to the triggered aftershocks.

  6. Improving the resolution of the 2010 Haiti earthquake fault geometry using temporary seismometer deployments

    NASA Astrophysics Data System (ADS)

    Douilly, R.; Haase, J. S.; Ellsworth, W. L.; Bouin, M.; Calais, E.; Symithe, S. J.; Armbruster, J. G.; Mercier De Lepinay, B. F.; Deschamps, A.; Meremonte, M. E.; Hough, S. E.; Saint Louis, M.

    2012-12-01

    Haiti has been the locus of a number of large and damaging historical earthquakes. The recent January 12, 2010, Mw 7.0 earthquake affected cities that were largely unprepared, which resulted in tremendous losses. It was initially assumed that the earthquake ruptured the Enriquillo Plantain Garden Fault (EPGF), a major active structure in southern Haiti, known from geodetic measurements and its geomorphic expression to be capable of producing M7 or larger earthquakes. However, GPS and InSAR data showed that the event ruptured a previously unmapped fault, the Léogâne fault, a north dipping oblique blind thrust located immediately north of the Enriquillo Fault. Following the earthquake several groups installed temporary seismic stations to record aftershocks, including ocean bottom seismometers on either side of the EPGF. We use data from the complete set of stations deployed after the event, on land and offshore, to relocate all aftershocks from 10 February to 24 June 2010, to determine a one-dimensional regional crustal velocity model, and calculate focal mechanisms. The aftershock locations from the combined data set clearly delineate the Léogâne fault, with a geometry close to that inferred from geodetic data. Its strike and dip closely agrees with that of the global centroid moment tensor solution of the mainshock, but it is more steeply dipping than the plane inferred from previously determined finite fault inversions. The aftershocks also delineate a structure with shallower southward dip offshore and to the west of the rupture zone, which could indicate triggered seismicity on the offshore Trois Baies reverse fault. We use first-motion focal mechanisms to clarify the relationship of the fault geometry to the triggered aftershocks.

  7. Interaction of weak faults and non-newtonian rheology produces plate tectonics in a 3D model of mantle flow

    NASA Astrophysics Data System (ADS)

    Zhong, Shijie; Gurnis, Michael

    1996-09-01

    ACCORDING to the theory of plate tectonics, relatively rigid plates are bounded by large faults; plate motion has negligible internal strain1,2,with significant toroidal component to the velocity3. By contrast, models of mantle flow with viscous rheology in an intact medium predict little toroidal component and substantial internal strain in surface motion4. It has been suggested5 that the observed characteristics of plate motion are related to faulted plate margins, which are observed to be weak6. Here we confirm this suggestion, using three-dimensional models of mantle flow that incorporate faults and the forces exerted on plates by subducting slabs ("slab pull') and mid-ocean ridges ('ridge push'). Our models show that plate-like motion results from the interaction between weak faults and a strain-weakening power-law rheology. Weak transform faults tend to guide plate motion. This guiding effect and the decoupling that occurs at thrust faults may result in oblique subduction. Convergent margins are associated with realistic trench and fore-bulge topography. By simultaneously predicting surface kinematics, topography and gravity, the models achieve a useful degree of tectonic realism.

  8. The role of salt layers in the hangingwall deformation of kinked-planar extensional faults: Insights from 3D analogue models and comparison with the Parentis Basin

    NASA Astrophysics Data System (ADS)

    Ferrer, O.; Roca, E.; Vendeville, B. C.

    2014-12-01

    Using an analogue modelling approach, this work investigates the role played by salt in the hangingwall deformation of an extensional fault. Models' set-up included a wooden block simulating the footwall of different kinked-planar fault geometries flattening at depth. Above these faults, the hangingwall was modelled using only sand or sand overlain by pre- or syn-kinematic silicone putty. Regardless of the stage at which was deposited, the silicone appears as an efficient decoupling level that changes the deformation mode of the overlying sand layers. Above the silicone layers, the rollover panels only continue to develop up to the welding of the underlying silicone. Afterwards, they do not grow anymore and all shearing induced by the underlying fault bends is accommodated along the tilted silicone layer that acts as an extensional shear band. Further fault slip produces near-horizontal growth stratal geometries that can be easily misinterpreted as a syn-rift/post-rift boundary. In addition, the differential sedimentary loading of syn-kinematic layers triggers the upslope silicone flow from the hangingwall depocenters towards the rollover shoulders. This migration results in the formation of silicone welds at the rollover limbs and the growth of gentle silicone-cored anticlines above or near the rollover shoulder that are locally pierced by diapirs and walls. These experimental results fit with the Parentis Basin structure that, formed from the motion of lithosphere-scale kinked-planar extensional faults, includes salt inflated anticlines above their rollover shoulders and an intra-Albian unconformity interpreted now as syn-kinematic.

  9. Testing the influence of vertical, pre-existing joints on normal faulting using analogue and 3D discrete element models (DEM)

    NASA Astrophysics Data System (ADS)

    Kettermann, Michael; von Hagke, Christoph; Virgo, Simon; Urai, Janos L.

    2015-04-01

    Brittle rocks are often affected by different generations of fractures that influence each other. We study pre-existing vertical joints followed by a faulting event. Understanding the effect of these interactions on fracture/fault geometries as well as the development of dilatancy and the formation of cavities as potential fluid pathways is crucial for reservoir quality prediction and production. Our approach combines scaled analogue and numerical modeling. Using cohesive hemihydrate powder allows us to create open fractures prior to faulting. The physical models are reproduced using the ESyS-Particle discrete element Modeling Software (DEM), and different parameters are investigated. Analogue models were carried out in a manually driven deformation box (30x28x20 cm) with a 60° dipping pre-defined basement fault and 4.5 cm of displacement. To produce open joints prior to faulting, sheets of paper were mounted in the box to a depth of 5 cm at a spacing of 2.5 cm. Powder was then sieved into the box, embedding the paper almost entirely (column height of 19 cm), and the paper was removed. We tested the influence of different angles between the strike of the basement fault and the joint set (0°, 4°, 8°, 12°, 16°, 20°, and 25°). During deformation we captured structural information by time-lapse photography that allows particle imaging velocimetry analyses (PIV) to detect localized deformation at every increment of displacement. Post-mortem photogrammetry preserves the final 3-dimensional structure of the fault zone. We observe that no faults or fractures occur parallel to basement-fault strike. Secondary fractures are mostly oriented normal to primary joints. At the final stage of the experiments we analyzed semi-quantitatively the number of connected joints, number of secondary fractures, degree of segmentation (i.e. number of joints accommodating strain), damage zone width, and the map-view area fraction of open gaps. Whereas the area fraction does not change distinctly, the number of secondary fractures and connected joints increases strongly with increasing angles between basement fault and joint strike. Integrating these models with a 3-dimensional DEM code using the ESyS-Particle software allows for retrieving 4D information from the models, as well as for testing other parameters such as joint spacing or joint depth. Our DEM models are capable of robustly reproducing all characteristic features observed in the analogue models, and will provide a quantitative measure of the influence of joint-fault angle on permeability of cohesive rocks that have experienced more than one brittle deformation phase.

  10. Influence of pre-existing basement faults on the structural evolution of the Zagros Simply Folded belt: 3D numerical modelling

    NASA Astrophysics Data System (ADS)

    Ruh, Jonas B.; Gerya, Taras

    2015-04-01

    The Simply Folded Belt of the Zagros orogen is characterized by elongated fold trains symptomatically defining the geomorphology along this mountain range. The Zagros orogen results from the collision of the Arabian and the Eurasian plates. The Simply Folded Belt is located southwest of the Zagros suture zone. An up to 2 km thick salt horizon below the sedimentary sequence enables mechanical and structural detachment from the underlying Arabian basement. Nevertheless, deformation within the basement influences the structural evolution of the Simply Folded Belt. It has been shown that thrusts in form of reactivated normal faults can trigger out-of-sequence deformation within the sedimentary stratigraphy. Furthermore, deeply rooted strike-slip faults, such as the Kazerun faults between the Fars zone in the southeast and the Dezful embayment and the Izeh zone, are largely dispersing into the overlying stratigraphy, strongly influencing the tectonic evolution and mechanical behaviour. The aim of this study is to reveal the influence of basement thrusts and strike-slip faults on the structural evolution of the Simply Folded Belt depending on the occurrence of intercrustal weak horizons (Hormuz salt) and the rheology and thermal structure of the basement. Therefore, we present high-resolution 3D thermo-mechnical models with pre-existing, inversively reactivated normal faults or strike-slip faults within the basement. Numerical models are based on finite difference, marker-in-cell technique with (power-law) visco-plastic rheology accounting for brittle deformation. Preliminary results show that deep tectonic structures present in the basement may have crucial effects on the morphology and evolution of a fold-and-thrust belt above a major detachment horizon.

  11. The 3D fault and vein architecture of strike-slip releasing- and restraining bends: Evidence from volcanic-centre-relatedmineral deposits

    USGS Publications Warehouse

    Berger, B.R.

    2007-01-01

    High-temperature, volcanic-centre-related hydrothermal systems involve large fluid-flow volumes and are observed to have high discharge rates in the order of 100-400 kg/s. The flows and discharge occur predominantly on networks of critically stressed fractures. The coupling of hydrothermal fluid flow with deformation produces the volumes of veins found in epithermal mineral deposits. Owing to this coupling, veins provide information on the fault-fracture architecture in existence at the time of mineralization. They therefore provide information on the nature of deformation within fault zones, and the relations between different fault sets. The Virginia City and Goldfield mining districts, Nevada, were localized in zones of strike-slip transtension in an Early to Mid-Miocene volcanic belt along the western margin of North America. The Camp Douglas mining area occurs within the same belt, but is localized in a zone of strike-slip transpression. The vein systems in these districts record the spatial evolution of strike-slip extensional and contractional stepovers, as well as geometry of faulting in and adjacent to points along strike-slip faults where displacement has been interrupted and transferred into releasing and restraining stepovers. ?? The Geological Society of London 2007.

  12. 3D modeling of architectural objects from video data obtained with the fixed focal length lens geometry

    NASA Astrophysics Data System (ADS)

    Deli?, Paulina; K?dzierski, Micha?; Fry?kowska, Anna; Wili?ska, Michalina

    2013-12-01

    The article describes the process of creating 3D models of architectural objects on the basis of video images, which had been acquired by a Sony NEX-VG10E fixed focal length video camera. It was assumed, that based on video and Terrestrial Laser Scanning data it is possible to develop 3D models of architectural objects. The acquisition of video data was preceded by the calibration of video camera. The process of creating 3D models from video data involves the following steps: video frames selection for the orientation process, orientation of video frames using points with known coordinates from Terrestrial Laser Scanning (TLS), generating a TIN model using automatic matching methods. The above objects have been measured with an impulse laser scanner, Leica ScanStation 2. Created 3D models of architectural objects were compared with 3D models of the same objects for which the self-calibration bundle adjustment process was performed. In this order a PhotoModeler Software was used. In order to assess the accuracy of the developed 3D models of architectural objects, points with known coordinates from Terrestrial Laser Scanning were used. To assess the accuracy a shortest distance method was used. Analysis of the accuracy showed that 3D models generated from video images differ by about 0.06 ÷ 0.13 m compared to TLS data. Artyku? zawiera opis procesu opracowania modeli 3D obiektów architektonicznych na podstawie obrazów wideo pozyskanych kamer? wideo Sony NEX-VG10E ze sta?oogniskowym obiektywem. Przyj?to za?o?enie, ?e na podstawie danych wideo i danych z naziemnego skaningu laserowego (NSL) mo?liwe jest opracowanie modeli 3D obiektów architektonicznych. Pozyskanie danych wideo zosta?o poprzedzone kalibracj? kamery wideo. Model matematyczny kamery by? oparty na rzucie perspektywicznym. Proces opracowania modeli 3D na podstawie danych wideo sk?ada? si? z nast?puj?cych etapów: wybór klatek wideo do procesu orientacji, orientacja klatek wideo na podstawie wspó?rz?dnych odczytanych z chmury punktów NSL, wygenerowanie modelu 3D w strukturze TIN z wykorzystaniem metod automatycznej korelacji obrazów. Opracowane modele 3D zosta?y porównane z modelami 3D tych samych obiektów, dla których zosta?a przeprowadzona samokalibracja metod? wi?zek. W celu oceny dok?adno?ci opracowanych modeli 3D obiektów architektonicznych wykorzystano punkty naziemnego skaningu laserowego. Do oceny dok?adno?ci wykorzystano metod? najkrótszej odleg?o?ci. Analiza dok?adno?ci wykaza?a, ?e dok?adno?? modeli 3D generowanych na podstawie danych wideo wynosi oko?o 0.06 ÷ 0.13m wzgl?dem danych NSL.

  13. Description of the Active Tectonic Deformation and Fault Friction in Iran Using Block and 3D Finite Element Modeling

    NASA Astrophysics Data System (ADS)

    Vernant, P.; Chery, J.

    2004-12-01

    The intracontinental deformation involved in the eastern part of the Arabia/Eurasia collision zone (i.e., mainly Iran) is distributed among several orogens (Zagros, Caucasus, Alborz, Kopet-Dag) surrounding rigid blocks (South Caspian, Central Iran, Lut, Helmand). In this study we investigate the more appropiated desciption of the active tectonic deformation in Iran using different modeling approaches. To do so, we have developed models of the eastern part of the Arabia/Eurasia collision ranging from eastern Turkey (~43°E) to western Afghanistan (~63°E) and from the Arabian to the Eurasian plate. The available GPS velocity fields (Vernant et al., 2004) are used to constrain (block model) or set-up the boundary conditions (finite element modeling). Two different rheologies are used for the finite element modeling: (a) one visco-elastic layer, (b) two layers: the upper one corresponds to the crust and the lower one to the lithospheric mantle. The great strike-slip faults are treated as vertical material discontinuities of the mesh. Fault slip-rates ranging from 0.3 to 0.02 are controlled by a Coulomb-type friction. A third rheology is used corresponding to the block model: (c) elastic constitutive law with fault friction = 0. The rms of the residuals (observed - modeled velocity field) are compared for the different experiments. The statistics obtained are close for the three different rheologies implying that the GPS data are too sparse to definitely conclude about the best description of the active deformation in Iran. However, elasto-plastic or elastic rheologies with law fault frictions show a slightly better fit to the GPS data. This is confirmed by the comparison between the geological fault slip rates and the modeled ones, suggesting that the active tectonic deformation in Iran can be described using rigid blocks and very low fault slip rate (0.02 to 0.0). However, more GPS measurement need to be done to conclude if the deformation is only accommodated by rigid blocks and faults or if elasto-plastic deformation zones exist somewhere in this part of the Alpine-Himalayan mountain belt.

  14. Lithological 3D grid model of the Vuonos area built by using geostatistical simulation honoring the 3D fault model and structural trends of the Outokumpu association rocks in Eastern Finland

    NASA Astrophysics Data System (ADS)

    Laine, Eevaliisa

    2015-04-01

    The Outokumpu mining district - a metallogenic province about 100 km long x 60 km wide - hosts a Palaeoproterozoic sulfide deposit characterized by an unusual lithological association. It is located in the North Karelia Schist Belt , which was thrust on the late Archaean gneissic-granitoid basement of the Karelian craton during the early stages of the Svecofennian Orogeny between 1.92 and 1.87 Ga (Koistinen 1981). Two major tectono-stratigraphic units can be distinguished, a lower, parautochthonous 'Lower Kaleva' unit and an upper, allochthonous 'upper Kaleva' unit or 'Outokumpu allochthon'. The latter consists of tightly-folded deep marine turbiditic mica schists and metagraywackes containing intercalations of black schist, and the Outo¬kumpu assemblage, which comprises ca. 1950 Ma old, serpentinized peridotites surrounded by carbonate-calc-silicate ('skarn')-quartz rocks. The ore body is enclosed in the Outokumpu assemblage, which is thought to be part of a disrupted and incomplete ophiolite complex (Vuollo & Piirainen 1989) that can be traced to the Kainuu schist belt further north where the well-preserved Jormua ophiolite is ex¬posed (Kontinen 1987, Peltonen & Kontinen 2004). Outokumpu can be divided into blocks divided by faults and shear zones (Saalmann and Laine, 2014). The aim of this study was to make a 3D lithological model of a small part of the Outokumpu association rocks in the Vuonos area honoring the 3D fault model built by Saalmann and Laine (2014). The Vuonos study area is also a part of the Outokumpu mining camp area (Aatos et al. 2013, 2014). Fault and shear structures was used in geostatistical gridding and simulation of the lithologies. Several possible realizations of the structural grids, conforming the main lithological trends were built. Accordingly, it was possible to build a 3D structural grid containing information of the distribution of the possible lithologies and an estimation the associated uncertainties. References: Aatos, S., Jokinen, J., Koistinen, E., Kontinen, A., Korhonen, J., Korpisalo, J., Kurimo, M.,Lahti, I., Laine, E., Levaniemi, H., Sorjonen-Ward, P. & Torppa, J. 2014. Developing deep exploration methods in the Outokumpu Mining Camp area. In: Lauri, L. S., Heilimo, E., Levaniemi, H., Tuusjarvi, M., Lahtinen, R. & Holtta, P. (eds) Current Research: 2nd GTK Mineral Potential Workshop, Kuopio, Finland, May 2014. Geological Survey of Finland,Report of Investigation 207. Koistinen, T. J., 1981. Structural evolution of an early Proterozoic strata-bound Cu-Co-Zn deposit, Outokumpu, Finland. Transactions of the Royal Society of Edinburgh: Earth Sciences, 72, pp. 115-158. Kontinen,A., 1987.An early Proterozoic ophiolite -- the Jormuamafic-ultramafic complex, northern Finland. Precambrian Research 35, 313-341. Peltonen, P. & Kontinen, A. 2004. The Jormua Ophiolite: a mafic-ultramafic complex from an ancient ocean-continent transition zone. In: Precambrian ophiolites and related rocks. Developments in Precambrian geology 13. Amsterdam: Elsevier, 35-71. Saalmann, K.; Laine, E.L, 2014. Structure of the Outokumpu ore district and ophiolite-hosted Cu-Co-Zn-Ni-Ag-Au sulfide deposits revealed from 3D modeling and 2D high-resolution seismic reflection data. Ore Geology Reviews, Volume 62, October 2014, Pages 156-180. Vuollo, J., and Piirainen, T., 1989. Mineralogical evidence for an ophiolite from the Outokumpu serpentinites in North Karelia, Finland. Bulletin of the Geological Society of Finland 61, 95-112.

  15. The value of inclined coreholes for characterizing the geometry of 3-D fracture networks in bedrock aquifers

    NASA Astrophysics Data System (ADS)

    Munn, Jonathan; Parker, Beth

    2013-04-01

    In bedrock aquifers where matrix permeability is low, the nature and distribution of the fracture network has a strong impact on the transport and fate of contaminants. Accurate fracture characterization is therefore essential to fully understand the flow system and to predict contaminant migration. Powerful DFN models exist, yet the limitation is often on obtaining field data of sufficient quality to use as input parameters. One major contributing factor is the common practice of using only vertical coreholes to characterize bedrock aquifers. This can lead to datasets that are significantly biased toward fractures perpendicular to the corehole and are therefore not well suited for three-dimensional (3-D) fracture geometry characterization. This bias is particularly pronounced in flat-lying sedimentary strata where fracture networks are typically comprised of flat-lying bedding parallel fractures and vertical, or near vertical joints. An examination of such bias was conducted at a contaminated site in Guelph, Ontario, Canada, in a Silurian dolostone aquifer. Three inclined coreholes plunging 60 degrees with varying azimuths were drilled between 2010 and 2012 to supplement existing data from eleven vertical coreholes from previous investigations. Depth discrete datasets were collected in the coreholes including lithological and fracture logs from rock core, downhole geophysical surveys (e.g, acoustic televiewer, formation conductivity, temperature, natural gamma), and hydraulic testing including the first use of flexible liner profiling in inclined coreholes. These datasets were integrated to provide estimates of fracture frequency, orientation and aperture distributions and to estimate values of bulk effective fracture porosity. Orientation analysis revealed three dominant fracture sets on site that vary in intensity through mechanical layers. These sets consist of a horizontal, bedding-plane set with an average spacing of 0.3m, and two high-angle sets, NE-SW and WNW-ESE striking, with average spacings of 1.5m and 2.1m, respectively. When data from only the vertical coreholes are used for the analysis, only two fracture sets are identifiable: a bedding plane set and a high-angle E-W set, confirming the necessity of inclined coreholes for complete fracture orientation analysis. Hydraulic fracture apertures were estimated using the cubic law and range from 15 to 407 ?m with a geometric mean of 125 ?m. The fracture network properties will ultimately be used as input parameters for static and dynamic discrete fracture network models to assess current and future risks to nearby municipal supply wells. The study shows that inclined coreholes of varying orientation can help minimize sampling bias, and thereby provide a more representative sample of the fracture network.

  16. Marrow-Derived Stem Cell Motility in 3D Synthetic Scaffold Is Governed by Geometry Along With Adhesivity and Stiffness

    E-print Network

    Peyton, Shelly R.

    Design of 3D scaffolds that can facilitate proper survival, proliferation, and differentiation of progenitor cells is a challenge for clinical applications involving large connective tissue defects. Cell migration within ...

  17. Application of an inverse method for calculating three-dimensional fault geometries and clip vectors, Nun River Field, Nigeria

    SciTech Connect

    Kerr, H.G.; White, N.

    1996-03-01

    A general, automatic method for determining the three-dimensional geometry of a normal fault of any shape and size is applied to a three-dimensional seismic reflection data set from the Nun River field, Nigeria. In addition to calculating fault geometry, the method also automatically retrieves the extension direction without requiring any previous information about either the fault shape or the extension direction. Solutions are found by minimizing the misfit between sets of faults that are calculated from the observed geometries of two or more hanging-wall beds. In the example discussed here, the predicted fault surface is in excellent agreement with the shape of the seismically imaged fault. Although the calculated extension direction is oblique to the average strike of the fault, the value of this parameter is not well resolved. Our approach differs markedly from standard section-balancing models in two important ways. First, we do not assume that the extension direction is known, and second, the use of inverse theory ensures that formal confidence bounds can be determined for calculated fault geometries. This ability has important implications for a range of geological problems encountered at both exploration and production scales. In particular, once the three-dimensional displacement field has been constrained, the difficult but important problem of three-dimensional palinspastic restoration of hanging-wall structures becomes tractable.

  18. Geodetic imaging of potential seismogenic asperities on the Xianshuihe-Anninghe-Zemuhe fault system, southwest China, with a new 3-D viscoelastic interseismic coupling model

    NASA Astrophysics Data System (ADS)

    Jiang, Guoyan; Xu, Xiwei; Chen, Guihua; Liu, Yajing; Fukahata, Yukitoshi; Wang, Hua; Yu, Guihua; Tan, Xibin; Xu, Caijun

    2015-03-01

    We use GPS and interferometric synthetic aperture radar (InSAR) measurements to image the spatial variation of interseismic coupling on the Xianshuihe-Anninghe-Zemuhe (XAZ) fault system. A new 3-D viscoelastic interseismic deformation model is developed to infer the rotation and strain rates of blocks, postseismic viscoelastic relaxation, and interseismic slip deficit on the fault surface discretized with triangular dislocation patches. The inversions of synthetic data show that the optimal weight ratio and smoothing factor are both 1. The successive joint inversions of geodetic data with different viscosities reveal six potential fully coupled asperities on the XAZ fault system. Among them, the potential asperity between Shimian and Mianning, which does not exist in the case of 1019 Pa s, is confirmed by the published microearthquake depth profile. Besides, there is another potential partially coupled asperity between Daofu and Kangding with a length scale up to 140 km. All these asperity sizes are larger than the minimum resolvable wavelength. The minimum and maximum slip deficit rates near the Moxi town are 7.0 and 12.7 mm/yr, respectively. Different viscosities have little influence on the roughness of the slip deficit rate distribution and the fitting residuals, which probably suggests that our observations cannot provide a good constraint on the viscosity of the middle lower crust. The calculation of seismic moment accumulation on each segment indicates that the Songlinkou-Selaha (S4), Shimian-Mianning (S7), and Mianning-Xichang (S8) segments are very close to the rupture of characteristic earthquakes. However, the confidence level is confined by sparse near-fault observations.

  19. Pushing the Limits of Geological Mapping Outside the Earth: 3D Modeling of Strike-Slip and Extensional Fault Systems in Meridiani Planum Region, Mars.

    NASA Astrophysics Data System (ADS)

    Vidal Royo, O.

    2014-12-01

    GIS and geological modeling software have radically changed the means by which geological mapping is produced, published and visualized. This type of software environment normally requires a spatially aware reference system to position data and interpretation, often referred as georeferenced data (i.e. geographic data referenced on the Earth). However, for this study we coin the term areoreferenced data (i.e. Mars-referenced "geographic" data). Thanks to the wealth of areoreferenced data made available by the NASA and the HiRise at University of Arizona it is now possible to carry out 3D areographic and areologic (i.e. related to the topography and geology of Mars, respectively) reconstructions in great detail. The present work benefits from the availability of software and areographic data, and presents the results of an areologic map and 3D model of the fault systems in the Meridiani Planum of Mars. The work has been carried out in Move™ (developed by Midland Valley Exploration), a geological modeling toolkit that allows for easy data loading in a wide range of formats as well as straightforward 2D/3D model building tools of geological bodies. Initial data consisted of Digital Terrain Model and orthoimages (NASA/JPL/University of Arizona/USGS). From these we have interpreted several structural domains: right-lateral strike-slip systems with associated releasing bends, which gave room to an extensional event causing a horizontal-axis rotation of the bedding. Bedding ranges from subhorizontal in the southern domain where strike-slip prevails to nearly 40º in the central and northern domains, where a more complex interaction between strike-slip and extensional faults is described. The stratigraphic sequence is mainly composed by moderately rounded well laminated basaltic sandstones (Squyres et al., 2004) in which a high component of sulfurs (e.g. sulfate anhydrate, hexahydrite, epsomite, gypsum) and salts (e.g. halite) has been described (Squyres et al., 2004; Christensen et al., 2004). This presence of sulfurs and salts do not only evidence the presence of water in Mars in the past, but also makes us consider the presence of deeper layers that may constitute potential décollement levels on which the faults detach, as it has been described in extensional and compressional cordilleras elsewhere in the Earth.

  20. How Students Solve Problems in Spatial Geometry while Using a Software Application for Visualizing 3D Geometric Objects

    ERIC Educational Resources Information Center

    Widder, Mirela; Gorsky, Paul

    2013-01-01

    In schools, learning spatial geometry is usually dependent upon a student's ability to visualize three dimensional geometric configurations from two dimensional drawings. Such a process, however, often creates visual obstacles which are unique to spatial geometry. Useful software programs which realistically depict three dimensional geometric…

  1. Improving the resolution of the 2010 Haiti earthquake fault geometry using temporary seismometer deployments

    NASA Astrophysics Data System (ADS)

    Douilly, R.; Haase, J. S.; Ellsworth, W. L.; Bouin, M.; Calais, E.; Armbruster, J. G.; Mercier De Lepinay, B. F.; Deschamps, A.; Saint Louis, M.; Meremonte, M. E.; Hough, S. E.

    2011-12-01

    Haiti has several active faults that are capable of producing large earthquakes such as the 2010 Mw 7.0 Haiti earthquake. This earthquake was not unexpected, given geodetic measurements showing strain accumulation on the Enriquillo Plantain Garden Fault Zone, the major fault system in southern Haiti (Manaker et al. 2008). GPS and INSAR data (Calais et al., 2010) show, however, that this rupture occurred on the previously unmapped Léogâne fault, a 60° north dipping oblique blind thrust located immediately north of the Enriquillo Fault. Following the earthquake, several groups installed temporary seismic stations to record aftershocks. Natural Resources Canada installed three broadband seismic stations, Géoazur installed 21 ocean bottom seismometers, L'Institut de Physique du Globe de Paris installed 5 broadband seismometers, and the United States Geological Survey deployed 17 short period and strong motion seismometers in and around Port-au-Prince. We use data from this complete set of stations, along with data from permanent regional stations, to relocate all of the events from March 17 to June 24, to determine the regional one-dimensional crustal structure and determine focal mechanisms. The aftershock locations from the combined data set clearly delineate the Léogâne fault. The strike and dip closely agrees with that of the global centroid moment tensor solution, but appears to be more steeply dipping than the finite fault inversions. The aftershocks also delineate a flat structure on the west side of the rupture zone and may indicate triggered seismicity on the Trois Baies fault, although the depths of these events are not as well constrained. There is no clear evidence for aftershocks on the other rupture segments inferred in the Hayes et al. (2010) mainshock rupture model. There is a cluster of aftershocks in the hanging wall near the western patch of high slip identified by Calais et al. (2010) and Meng et al. (2011), or central patch in the Hayes et al. (2010) model. We use first-motion focal mechanism solutions to clarify the relationship of the fault geometry to the mechanisms of the larger events.

  2. 3D model of fault and fissures structure of the Kovdor Baddeleyite-Apatite-Magnetite Deposit (NE of the Fennoscandian Shield)

    NASA Astrophysics Data System (ADS)

    Zhirov, Dmitry; Klimov, Sergey

    2015-04-01

    The Kovdor baddeleyite-apatite-magnetite deposit (KBAMD) is represented by a large vertical ore body and is located in the southwestern part of the Kovdor ultramafic-alkaline central-type intrusion. The intrusion represents a concentrically zoned complex of rocks with an oval shape in plan, and straight zoning, which complies with the injection and displacement of each of further magma phases from the center towards the periphery. The operation of the deposit in open pits started in 1962, and nowadays, it has produced over 500,000,000 tons of ore. This is one of the largest open pits in the Kola region, which is ca. 2 km long, 1.8 km wide, and over 400 m deep. Regular structural studies has been carried out since late 1970. A unique massif of spatial data has been accumulated so far to include over 25,000 measurements of fissures and faults from the surface, ca. 20,000 measurements of fissures in the oriented drill core (over 18 km) etc. Using this data base the 3D model of fault and fissures structure was designed. The analysis of one has resulted in the identification of a series of laws and features, which are necessary to be taken into account when designing a deep open pit and mining is carried out. These are mainly aspects concerning the origin, kinematics, mechanics and ratio of spatial extension of various fault systems, variation of their parameters at deep horizons, features of a modern stress field in the country rocks, etc. The 3D model has allowed to divide the whole fracture / fissure systems of the massif rocks into 2 large groups: prototectonic system of joints, including cracks of 'liquid magmatic (carbonatite stage) contraction genesis', and newly formed faults due to the superimposed tectonic stages. With regard to the deposit scale, these are characterized as intraformational and transformational, respectively. Each group shows a set (an assemblage) of fault systems with unique features and signs, as well as regular interconnections. The prototectonic assemblage of fissures includes the following main systems: 2-3 subsystems Rd of radial with angle of dip within 65-90° (median at 78°), two subsystems S of a circular subvertical (tangential, crossing Rd) with angle of dip within 60-90° (74°), and two diagonal-conic ones: a centriclinal C dipping towards the center of the intrusion at angles of 25-55° (43°), and a periclinal P dipping from the center of the intrusion at angles of 5-35° (18°). The system of subhorizontal joints L (angle of dip within 0-12°) at deep horizons is insignificantly manifested. All the prototectonic systems are regularly interrelated, and vary asymuthal features according to the law of axial symmetry (when moving around the vertical axis of symmetry passed through the geometric center of the carbonatite intrusion). The superimposed tectonics of post-ore stages forms a few large faults and systems of rupture discontinuities. A few (up to 3) variously oriented displacements are documented in the field on kinematic features (slide furrows, oriented cleavages). They were used for reconstruction of stresses and tectonic evolution. The superimposed tectonic faulting has heterogeneous (local) distribution in the rocks of the deposit, and slight predictability of main parameters. This study was supported by the Russian Scientific Fund (project nos. 14-17-00751).

  3. Imaging the Fault Geometry From the Multi-Channel Seismic Reflection Data in the Marmara Sea, Tekirdag Basin, Turkey

    NASA Astrophysics Data System (ADS)

    Kanbur, Z.; Alptekin, O.

    2002-05-01

    Determination of the fault geometry in the Marmara Sea has been a major problem for the researchers after the occurence of 17 August 1999 ?zmit (M=7.4) and 12 Novenber 1999 D\\x81zce (M=7.2) earthquakes. We used Pre-Stack Kirchhoff Depth Migration Technique to ivestigate the fault geometry in the Tekirda? Basin in western Marmara Sea by using the multi-channel seismic reflection data collected by Mineral Research Institute of Turkey ( MTA). Our results show that using the Kirchhoff technique the geometry of the fault plane can be imaged better comparing to the convensional technique. Our image of the Ganos fault indicates transpressive character in the west and transtensional character in the south margin of the Tekirda? basin. Imaging technique make the trust component visible in the migration section and show that the Ganos fault has multiple fault plane. These fault planes are imaged through the depth of 2750 m in the west of Tekirda? Basin. The major plane of Ganos fault dips 33 degrees toward south at 1750 m depth. The dip of the fault gradually decreases to 18 degrees till 2750 m. Another image cutting the basin in NS direction shows that the character of the Ganos fault is changed to transtensional and the whole section is like a flower structure. The fault plane dips 70 degrees toward north . The images obtained in this study not only confirm the preliminary results determined from conventional processing techniques but also provides significant additional information on the faults in the Marmara Sea.

  4. A 3D interface-enriched generalized finite element method for weakly discontinuous problems with complex internal geometries

    E-print Network

    Geubelle, Philippe H.

    A 3D interface-enriched generalized finite element method for weakly discontinuous problems study Heterogeneous materials a b s t r a c t An interface-enriched generalized finite element method/extended finite element methods (GFEM/ XFEM), first introduced in [1­4], is now widely used by the compu- tational

  5. The influence of normal fault geometry on porous sandstone deformation: Insights from mechanical models into conditions leading to Coulomb failure and shear-enhanced compaction

    NASA Astrophysics Data System (ADS)

    Allison, K.; Reinen, L. A.

    2011-12-01

    Slip on non-planar faults produces stress perturbations in the surrounding host rock that can yield secondary faults at a scale too small to be resolved on seismic surveys. Porosity changes during failure may affect the ability of the rock to transmit fluids through dilatant cracking or, in porous rocks, shear-enhanced compaction (i.e., cataclastic flow). Modeling the mechanical behavior of the host rock in response to slip on non-planar faults can yield insights into the role of fault geometry on regions of enhanced or inhibited fluid flow. To evaluate the effect of normal fault geometry on deformation in porous sandstones, we model the system as a linear elastic, homogeneous, whole or half space using the boundary-element modeling program Poly3D. We consider conditions leading to secondary deformation using the maximum Coulomb shear stress (MCSS) as an index of brittle deformation and proximity to an elliptical yield envelope (Y), determined experimentally for porous sandstone (Baud et al., JGR, 2006), for cataclastic flow. We model rectangular faults consisting of two segments: an upper leg with a constant dip of 60° and a lower leg with dips ranging 15-85°. We explore far-field stress models of constant and gradient uniaxial strain. We investigate the potential damage in the host rock in two ways: [1] the size of the damage zone, and [2] regions of enhanced deformation indicated by elevated MCSS or Y. Preliminary results indicate that, along a vertical transect passing through the fault kink, [1] the size of the damage zone increases in the footwall with increasing lower leg dip and remains constant in the hanging wall. [2] In the footwall, the amount of deformation does not change as a function of lower leg dip in constant stress models; in gradient stress models, both MCSS and Y increase with dip. In the hanging wall, Y decreases with increasing lower leg dip for both constant and gradient stress models. In contrast, MCSS increases: as lower leg dip increases for constant stress models, and as the difference between lower leg dip and 60° increases for gradient stress models. These preliminary results indicate that the dip of the lower fault segment significantly affects the amount and style of deformation in the host rock.

  6. R2OBBIE-3D, a Fast Robotic High-Resolution System for Quantitative Phenotyping of Surface Geometry and Colour-Texture

    PubMed Central

    Manukyan, Liana; Milinkovitch, Michel C.

    2015-01-01

    While recent imaging techniques provide insights into biological processes from the molecular to the cellular scale, phenotypes at larger scales remain poorly amenable to quantitative analyses. For example, investigations of the biophysical mechanisms generating skin morphological complexity and diversity would greatly benefit from 3D geometry and colour-texture reconstructions. Here, we report on R2OBBIE-3D, an integrated system that combines a robotic arm, a high-resolution digital colour camera, an illumination basket of high-intensity light-emitting diodes and state-of-the-art 3D-reconstruction approaches. We demonstrate that R2OBBIE generates accurate 3D models of biological objects between 1 and 100 cm, makes multiview photometric stereo scanning possible in practical processing times, and enables the capture of colour-texture and geometric resolutions better than 15 ?m without the use of magnifying lenses. R2OBBIE has the potential to greatly improve quantitative analyses of phenotypes in addition to providing multiple new applications in, e.g., biomedical science. PMID:26039509

  7. R(2)OBBIE-3D, a Fast Robotic High-Resolution System for Quantitative Phenotyping of Surface Geometry and Colour-Texture.

    PubMed

    Martins, António F; Bessant, Michel; Manukyan, Liana; Milinkovitch, Michel C

    2015-01-01

    While recent imaging techniques provide insights into biological processes from the molecular to the cellular scale, phenotypes at larger scales remain poorly amenable to quantitative analyses. For example, investigations of the biophysical mechanisms generating skin morphological complexity and diversity would greatly benefit from 3D geometry and colour-texture reconstructions. Here, we report on R(2)OBBIE-3D, an integrated system that combines a robotic arm, a high-resolution digital colour camera, an illumination basket of high-intensity light-emitting diodes and state-of-the-art 3D-reconstruction approaches. We demonstrate that R(2)OBBIE generates accurate 3D models of biological objects between 1 and 100 cm, makes multiview photometric stereo scanning possible in practical processing times, and enables the capture of colour-texture and geometric resolutions better than 15 ?m without the use of magnifying lenses. R(2)OBBIE has the potential to greatly improve quantitative analyses of phenotypes in addition to providing multiple new applications in, e.g., biomedical science. PMID:26039509

  8. 3D Geomodeling of the Venezuelan Andes

    NASA Astrophysics Data System (ADS)

    Monod, B.; Dhont, D.; Hervouet, Y.; Backé, G.; Klarica, S.; Choy, J. E.

    2010-12-01

    The crustal structure of the Venezuelan Andes is investigated thanks to a geomodel. The method integrates surface structural data, remote sensing imagery, crustal scale balanced cross-sections, earthquake locations and focal mechanism solutions to reconstruct fault surfaces at the scale of the mountain belt into a 3D environment. The model proves to be essential for understanding the basic processes of both the orogenic float and the tectonic escape involved in the Plio-Quaternary evolution of the orogen. The reconstruction of the Bocono and Valera faults reveals the 3D shape of the Trujillo block whose geometry can be compared to a boat bow floating over a mid-crustal detachment horizon emerging at the Bocono-Valera triple junction. Motion of the Trujillo block is accompanied by a generalized extension in the upper crust accommodated by normal faults with listric geometries such as for the Motatan, Momboy and Tuñame faults. Extension may be related to the lateral spreading of the upper crust, suggesting that gravity forces play an important role in the escape process.

  9. User's manual. SPIN, a program for 3-D axisymmetric geometry generation. [In FORTRAN for CDC 7600 and CRAY-1

    SciTech Connect

    Brown, B.E.

    1980-08-01

    SPIN is designed to take two-dimensional quadrilateral input, rotate the data about an axis, and produce three-dimensional bricks. The two-dimensional database is discussed in this manual (it is the same as the output of the ZONE program (UCID-17139)). The output of SPIN is in the format for the DYNA3D/NIKE3D programs (UCID-17268). Both the input and output files are card images, not binary, so the files may be easily edited with a text editor for any other program. Additionally, the slide-planes between various layers may also be generated. The program is available on both CDC7600 and CRAY-1 computers.

  10. The influence of fault geometry and frictional contact properties on slip surface behavior and off-fault damage: insights from quasi-static modeling of small strike-slip faults from the Sierra Nevada, CA

    NASA Astrophysics Data System (ADS)

    Ritz, E.; Pollard, D. D.

    2011-12-01

    Geological and geophysical investigations demonstrate that faults are geometrically complex structures, and that the nature and intensity of off-fault damage is spatially correlated with geometric irregularities of the slip surfaces. Geologic observations of exhumed meter-scale strike-slip faults in the Bear Creek drainage, central Sierra Nevada, CA, provide insight into the relationship between non-planar fault geometry and frictional slip at depth. We investigate natural fault geometries in an otherwise homogeneous and isotropic elastic material with a two-dimensional displacement discontinuity method (DDM). Although the DDM is a powerful tool, frictional contact problems are beyond the scope of the elementary implementation because it allows interpenetration of the crack surfaces. By incorporating a complementarity algorithm, we are able to enforce appropriate contact boundary conditions along the model faults and include variable friction and frictional strength. This tool allows us to model quasi-static slip on non-planar faults and the resulting deformation of the surrounding rock. Both field observations and numerical investigations indicate that sliding along geometrically discontinuous or irregular faults may lead to opening of the fault and the formation of new fractures, affecting permeability in the nearby rock mass and consequently impacting pore fluid pressure. Numerical simulations of natural fault geometries provide local stress fields that are correlated to the style and spatial distribution of off-fault damage. We also show how varying the friction and frictional strength along the model faults affects slip surface behavior and consequently influences the stress distributions in the adjacent material.

  11. Real-time inversions for finite fault slip models and rupture geometry based on high-rate GPS data

    USGS Publications Warehouse

    Minson, Sarah E.; Murray, Jessica R.; Langbein, John O.; Gomberg, Joan S.

    2015-01-01

    We present an inversion strategy capable of using real-time high-rate GPS data to simultaneously solve for a distributed slip model and fault geometry in real time as a rupture unfolds. We employ Bayesian inference to find the optimal fault geometry and the distribution of possible slip models for that geometry using a simple analytical solution. By adopting an analytical Bayesian approach, we can solve this complex inversion problem (including calculating the uncertainties on our results) in real time. Furthermore, since the joint inversion for distributed slip and fault geometry can be computed in real time, the time required to obtain a source model of the earthquake does not depend on the computational cost. Instead, the time required is controlled by the duration of the rupture and the time required for information to propagate from the source to the receivers. We apply our modeling approach, called Bayesian Evidence-based Fault Orientation and Real-time Earthquake Slip, to the 2011 Tohoku-oki earthquake, 2003 Tokachi-oki earthquake, and a simulated Hayward fault earthquake. In all three cases, the inversion recovers the magnitude, spatial distribution of slip, and fault geometry in real time. Since our inversion relies on static offsets estimated from real-time high-rate GPS data, we also present performance tests of various approaches to estimating quasi-static offsets in real time. We find that the raw high-rate time series are the best data to use for determining the moment magnitude of the event, but slightly smoothing the raw time series helps stabilize the inversion for fault geometry.

  12. Development and application of a 3-D geometry/mass model for LDEF satellite ionizing radiation assessments

    NASA Technical Reports Server (NTRS)

    Colborn, B. L.; Armstong, T. W.

    1993-01-01

    A three-dimensional geometry and mass model of the Long Duration Exposure Facility (LDEF) spacecraft and experiment trays was developed for use in predictions and data interpretation related to ionizing radiation measurements. The modeling approach, level of detail incorporated, example models for specific experiments and radiation dosimeters, and example applications of the model are described.

  13. A fractal approach to the dark silicon problem: A comparison of 3D computer architectures - Standard slices versus fractal Menger sponge geometry

    NASA Astrophysics Data System (ADS)

    Herrmann, Richard

    2015-01-01

    The dark silicon problem, which limits the power-growth of future computer generations, is interpreted as a heat energy transport problem when increasing the energy emitting surface area within a given volume. A comparison of two 3D-configuration models, namely a standard slicing and a fractal surface generation within the Menger sponge geometry is presented. It is shown, that for iteration orders $n>3$ the fractal model shows increasingly better thermal behavior. As a consequence cooling problems may be minimized by using a fractal architecture. Therefore the Menger sponge geometry is a good example for fractal architectures applicable not only in computer science, but also e.g. in chemistry when building chemical reactors, optimizing catalytic processes or in sensor construction technology building highly effective sensors for toxic gases or water analysis.

  14. Relationships between sliding behavior and internal geometry of laboratory fault zones and some creeping and locked strike-slip faults of California

    USGS Publications Warehouse

    Moore, Diane E.; Byerlee, J.

    1992-01-01

    Moore, D.E. and Byerlee, J., 1992. Relationships between sliding behavior and internal geometry of laboratory fault zones and some creeping and locked strike-slip faults of California. In: T. Mikumo, K. Aki, M. Ohnaka, L.J. Ruff and P.K.P. Spudich (Editors), Earthquake Source Physics and Earthquake Precursors. Tectonophysics, 211: 305-316. In order to relate fault geometries to sliding behavior, maps of recently active breaks within the Hayward fault of central California, which is characterized by fault creep, have been examined and compared to maps of the San Andreas fault. The patterns of recent breaks of the Hayward fault are consistent with those found within the creeping section of the San Andreas, and they appear to have plausible physical explanations in the findings of laboratory experiments. The distinguishing geometric features of the examined locked and creeping faults are: (1) P-type second-order traces predominate over R(Riedel)-type traces in creeping sections; and (2) R-type second-order traces make smaller angles to the local fault strike in creeping sections than they do in locked sections. Two different maps of the Hayward fault gave similar results, supporting the inference that the patterns identified are basic characteristics of the fault rather than artifacts of a particular mapping procedure. P shears predominate over R shears under laboratory conditions that allow dilation within the fault zone. In our own experiments, P-shear development was favored by the generation of excess pore-fluid pressures. We propose that creep in California faults also is the result of fluid overpressures that are maintained in a low-permeability gouge zone and that significantly lower effective stresses, thus helping to stabilize slip and producing high values of the ratio P/R. Small R-trace angles may also be an indicator of low effective stresses, but the evidence for this is not conclusive because other factors can also affect the size of the angles. ?? 1992.

  15. Structure Segmentation and Transfer Faults in the Marcellus Shale, Clearfield County, Pennsylvania: Implications for Gas Recovery Efficiency and Risk Assessment Using 3D Seismic Attribute Analysis

    NASA Astrophysics Data System (ADS)

    Roberts, Emily D.

    The Marcellus Shale has become an important unconventional gas reservoir in the oil and gas industry. Fractures within this organic-rich black shale serve as an important component of porosity and permeability useful in enhancing production. Horizontal drilling is the primary approach for extracting hydrocarbons in the Marcellus Shale. Typically, wells are drilled perpendicular to natural fractures in an attempt to intersect fractures for effective hydraulic stimulation. If the fractures are contained within the shale, then hydraulic fracturing can enhance permeability by further breaking the already weakened rock. However, natural fractures can affect hydraulic stimulations by absorbing and/or redirecting the energy away from the wellbore, causing a decreased efficiency in gas recovery, as has been the case for the Clearfield County, Pennsylvania study area. Estimating appropriate distances away from faults and fractures, which may limit hydrocarbon recovery, is essential to reducing the risk of injection fluid migration along these faults. In an attempt to mitigate the negative influences of natural fractures on hydrocarbon extraction within the Marcellus Shale, fractures were analyzed through the aid of both traditional and advanced seismic attributes including variance, curvature, ant tracking, and waveform model regression. Through the integration of well log interpretations and seismic data, a detailed assessment of structural discontinuities that may decrease the recovery efficiency of hydrocarbons was conducted. High-quality 3D seismic data in Central Pennsylvania show regional folds and thrusts above the major detachment interval of the Salina Salt. In addition to the regional detachment folds and thrusts, cross-regional, northwest-trending lineaments were mapped. These lineaments may pose a threat to hydrocarbon productivity and recovery efficiency due to faults and fractures acting as paths of least resistance for induced hydraulic stimulation fluids. These lineaments may represent major transfer faults that serve as pathways for hydraulic fluid migration. Detection and evaluation of fracture orientation and intensity and emphasis on the relationship between fracture intensity and production potential is of high interest in the study area as it entails significant time and cost implications for both conventional and unconventional hydrocarbon exploration and production.

  16. TU-F-BRF-04: Registration of 3D Transesophageal Echocardiography and X-Ray Fluoroscopy Using An Inverse Geometry X-Ray System

    SciTech Connect

    Speidel, M; Hatt, C; Tomkowiak, M; Raval, A; Funk, T

    2014-06-15

    Purpose: To develop a method for the fusion of 3D echocardiography and Scanning-Beam Digital X-ray (SBDX) fluoroscopy to assist with catheter device and soft tissue visualization during interventional procedures. Methods: SBDX is a technology for low-dose inverse geometry x-ray fluoroscopy that performs digital tomosynthesis at multiple planes in real time. In this study, transesophageal echocardiography (TEE) images were fused with SBDX images by estimating the 3D position and orientation (the “pose”) of the TEE probe within the x-ray coordinate system and then spatially transforming the TEE image data to match this pose. An initial pose estimate was obtained through tomosynthesis-based 3D localization of points along the probe perimeter. Position and angle estimates were then iteratively refined by comparing simulated projections of a 3D probe model against SBDX x-ray images. Algorithm performance was quantified by imaging a TEE probe in different known orientations and locations within the x-ray field (0-30 degree tilt angle, up to 50 mm translation). Fused 3D TEE/SBDX imaging was demonstrated by imaging a tissue-mimicking polyvinyl alcohol cylindrical cavity as a catheter was navigated along the cavity axis. Results: Detected changes in probe tilt angle agreed with the known changes to within 1.2 degrees. For a 50 mm translation along the source-detector axis, the detected translation was 50.3 mm. Errors for in-plane translations ranged from 0.1 to 0.9 mm. In a fused 3D TEE/SBDX display, the catheter device was well visualized and coincident with the device shadow in the TEE images. The TEE images portrayed phantom boundaries that were not evident under x-ray. Conclusion: Registration of soft tissue anatomy derived from TEE imaging and device imaging from SBDX x-ray fluoroscopy is feasible. The simultaneous 3D visualization of these two modalities may be useful in interventional procedures involving the navigation of devices to soft tissue anatomy.

  17. FACET: a radiation view factor computer code for axisymmetric, 2D planar, and 3D geometries with shadowing

    SciTech Connect

    Shapiro, A.B.

    1983-08-01

    The computer code FACET calculates the radiation geometric view factor (alternatively called shape factor, angle factor, or configuration factor) between surfaces for axisymmetric, two-dimensional planar and three-dimensional geometries with interposed third surface obstructions. FACET was developed to calculate view factors for input to finite-element heat-transfer analysis codes. The first section of this report is a brief review of previous radiation-view-factor computer codes. The second section presents the defining integral equation for the geometric view factor between two surfaces and the assumptions made in its derivation. Also in this section are the numerical algorithms used to integrate this equation for the various geometries. The third section presents the algorithms used to detect self-shadowing and third-surface shadowing between the two surfaces for which a view factor is being calculated. The fourth section provides a user's input guide followed by several example problems.

  18. 3D Simultaneous Traveltime Inversion for Velocity Structure, Hypocenter Locations, and Reflector Geometry Using Multiple Classes of Arrivals

    NASA Astrophysics Data System (ADS)

    Bai, Chao-ying; Huang, Guo-jiao; Li, Xing-wang; Greenhalgh, Stewart

    2015-10-01

    Traditionally, traveltime tomography entails inversion of either the velocity field and the reflector geometry sequentially, or the velocity field and the hypocenter locations simultaneously or in a cascaded fashion, but seldom are all three types (velocities, geometry of reflectors, and source locations) updated simultaneously because of the compromise between the different classes of model variable and the lack of different seismic phases to constrain these variables. By using a state-of-the-art ray-tracing algorithm for the first and later arrivals combined with a popular linearized inversion solver, it is possible to simultaneously recover the three classes of model variables. In the work discussed in this paper we combined the multistage irregular shortest-path ray-tracing algorithm with a subspace inversion solver to achieve simultaneous inversion of multi-class variables, using arrival times for different phases to concurrently obtain the velocity field, the reflector shapes, and the hypocenter locations. Simulation and comparison tests for two sets of source-receiver arrangements (one the ideal case and the other an approximated real case) indicate that the combined triple-class inversion algorithm is capable of obtaining nearly the same results as the double-class affect inversion scheme (velocity and reflector geometry, or velocity and source locations) even if a lower ray density and irregular source-receiver geometry are used to simulate the real situation. In addition, the new simultaneous inversion method is not sensitive to a modest amount of picking error in the traveltime data and reasonable uncertainty in earthquake hypocenter locations, which shows it to be a feasible and promising approach in real applications.

  19. Delineation of faulting and basin geometry along a seismic reflection transect in urbanized San Bernardino Valley, California

    USGS Publications Warehouse

    Stephenson, W.J.; Odum, J.K.; Williams, R.A.; Anderson, M.L.

    2002-01-01

    Fourteen kilometers of continuous, shallow seismic reflection data acquired through the urbanized San Bernardino Valley, California, have revealed numerous faults between the San Jacinto and San Andreas faults as well as a complex pattern of downdropped and uplifted blocks. These data also indicate that the Loma Linda fault continues northeastward at least 4.5 km beyond its last mapped location on the southern edge of the valley and to within at least 2 km of downtown San Bernardino. Previously undetected faults within the valley northeast of the San Jacinto fault are also imaged, including the inferred western extension of the Banning fault and several unnamed faults. The Rialto-Colton fault is interpreted southwest of the San Jacinto fault. The seismic data image the top of the crystalline basement complex across 70% of the profile length and show that the basement has an overall dip of roughly 10?? southwest between Perris Hill and the San Jacinto fault. Gravity and aeromagnetic data corroborate the interpreted location of the San Jacinto fault and better constrain the basin depth along the seismic profile to be as deep as 1.7 km. These data also corroborate other fault locations and the general dip of the basement surface. At least 1.2 km of apparent vertical displacement on the basement is observed across the San Jacinto fault at the profile location. The basin geometry delineated by these data was used to generate modeled ground motions that show peak horizontal amplifications of 2-3.5 above bedrock response in the 0.05- to 1.0-Hz frequency band, which is consistent with recorded earthquake data in the valley.

  20. Constraints on recent earthquake source parameters, fault geometry and aftershock characteristics in Oklahoma

    NASA Astrophysics Data System (ADS)

    McNamara, D. E.; Benz, H.; Herrmann, R. B.; Bergman, E. A.; McMahon, N. D.; Aster, R. C.

    2014-12-01

    In late 2009, the seismicity of Oklahoma increased dramatically. The largest of these earthquakes was a series of three damaging events (Mw 4.8, 5.6, 4.8) that occurred over a span of four days in November 2011 near the town of Prague in central Oklahoma. Studies suggest that these earthquakes were induced by reactivation of the Wilzetta fault due to the disposal of waste water from hydraulic fracturing ("fracking") and other oil and gas activities. The Wilzetta fault is a northeast trending vertical strike-slip fault that is a well known structural trap for oil and gas. Since the November 2011 Prague sequence, thousands of small to moderate (M2-M4) earthquakes have occurred throughout central Oklahoma. The most active regions are located near the towns of Stillwater and Medford in north-central Oklahoma, and Guthrie, Langston and Jones near Oklahoma City. The USGS, in collaboration with the Oklahoma Geological Survey and the University of Oklahoma, has responded by deploying numerous temporary seismic stations in the region in order to record the vigorous aftershock sequences. In this study we use data from the temporary seismic stations to re-locate all Oklahoma earthquakes in the USGS National Earthquake Information Center catalog using a multiple-event approach known as hypo-centroidal decomposition that locates earthquakes with decreased uncertainty relative to one another. Modeling from this study allows us to constrain the detailed geometry of the reactivated faults, as well as source parameters (focal mechanisms, stress drop, rupture length) for the larger earthquakes. Preliminary results from the November 2011 Prague sequence suggest that subsurface rupture lengths of the largest earthquakes are anomalously long with very low stress drop. We also observe very high Q (~1000 at 1 Hz) that explains the large felt areas and we find relatively low b-value and a rapid decay of aftershocks.

  1. Geophysical Investigation of the Offshore Section of the Northern San Andreas Fault: Fault Zone Geometries, Shallow Deformation Patterns, and Holocene Sediment Distribution

    NASA Astrophysics Data System (ADS)

    Beeson, J. W.; Goldfinger, C.; Johnson, S. Y.

    2014-12-01

    We mapped a ~120 km offshore section of the northern San Andreas Fault (NSAF) between Pt. Arena and Pt. Delgada using closely spaced seismic-reflection profiles, high-resolution multibeam bathymetry and marine magnetics data. This new dataset documents NSAF location and continuity, associated tectonic geomorphology, shallow stratigraphy and deformation. Variable deformation patterns in the generally narrow (~1-km-wide) fault zone are largely associated with fault trend and fault bends. We have described four regions (Pt. Arena, Basin, Shelter Cove, and Mendocino) along and adjacent to the NSAF based on fault trend, deformation styles, seismic stratigraphy, and seafloor bathymetry. The NSAF in the southern region (Pt. Arena) of the survey area is imaged as an arcuate fault trace that changes ~15° (327° to 342°) from south to north over a distance of about 50 km. The NSAF in the middle two regions (Basin and Shelter Cove) passes through two acute fault bends (~9° and ~8°), resulting in both an asymmetric "lazy z" sedimentary basin and an uplifted rocky shoal ("Tolo Bank"). The northwestern region of the survey area (Mendocino) lies west of the NSAF and Shelter Cove, and includes an east-trending fault zone related to the Mendocino transform fault that extends onshore near Punta Gorda. Using the densely spaced seismic-reflection profiles we have created an isopach map of Holocene sediment throughout the survey area. This isopach map has revealed thick sediment piles adjacent to coastal watersheds with high uplift rates. We infer from fault geometries, local bathymetry/topography and aero/marine magnetics that the NSAF zone transitions from a broadly distributed fault zone to a narrow fault zone over a short distance near Shelter Cove, Ca. At Shelter Cove the NSAF is characterized as a narrow, continuous fault. North of Shelter Cove the San Andreas likely terminates into a series of "horse tail" splay thrust faults known as the Kings Range Thrust. These observations allows for the NSAF near Shelter Cove, CA to accommodate significant slip, in agreement with paleoseismic studies and historical records.

  2. Density structure and geometry of the Costa Rican subduction zone from 3-D gravity modeling and local earthquake data

    NASA Astrophysics Data System (ADS)

    Lücke, O. H.; Arroyo, I. G.

    2015-07-01

    The eastern part of the oceanic Cocos Plate presents a heterogeneous crustal structure due to diverse origins and ages as well as plate-hot spot interactions which originated the Cocos Ridge, a structure that converges with the Caribbean Plate in southeastern Costa Rica. The complex structure of the oceanic plate directly influences the dynamics and geometry of the subduction zone along the Middle American Trench. In this paper an integrated interpretation of the slab geometry is presented based on three-dimensional density modeling of combined satellite and surface gravity data, constrained by available geophysical and geological data and seismological information obtained from local networks. The results show the continuation of steep subduction geometry from the Nicaraguan margin into Northwestern Costa Rica, followed by a moderate dipping slab under the Central Cordillera toward the end of the Central American Volcanic Arc. To the southeast end of the volcanic arc, our preferred model shows a steep, coherent slab that extends up to the landward projection of the Panama Fracture Zone. Overall, a gradual change in the depth of the intraplate seismicity is observed, reaching 220 km in the northwestern part, and becoming progressively shallower toward the southeast, where it reaches a terminal depth of 75 km. The changes in the terminal depth of the observed seismicity correlate with the increased density in the modeled slab. The absence of intermediate depth intraplate seismicity in the southeastern section and the higher densities for the subducted slab in this area, support a model in which dehydration reactions in the subducted slab cease at a shallower depth, originating an anhydrous and thus aseismic slab.

  3. 1-D closure models for slender 3-D viscoelastic free jets: von Karman flow geometry and elliptical cross section

    SciTech Connect

    Bechtel, S.E.; Forest, M.G.; Holm, D.D.; Lin, K.J.

    1988-01-01

    In this paper we derive one space dimensional, reduced systems of equations (1-D closure models) for viscoelastic free jets. We begin with the three-dimensional system of conservation laws and a Maxwell-Jeffreys constitutive law for an incompressible viscoelastic fluid. First, we exhibit exact truncations to a finite, closed system of 1-D equations based on classical velocity assumptions of von Karman. Next, we demonstrate that the 3-D free surface boundary conditions overconstrain these truncated systems, so that only a very limited class of solutions exist. We then proceed to derive approximate 1-D closure theories through a slender jet asymptotic scaling, combined with appropriate definitions of velocity, pressure and stress unknowns. Our nonaxisymmetric 1-D slender jet models incorporate the physical effects of inertia, viscoelasticity (viscosity, relaxation and retardation), gravity, surface tension, and properties of the ambient fluid, and include shear stresses and time dependence. Previous special 1-D slender jet models correspond to the lowest order equations in the present asymptotic theory by an a posteriori suppression to leading order of some of these effects, and a reduction to axisymmetry. Solutions of the lowest order system of equations in this asymptotic analysis are presented: For the special cases of elliptical inviscid and Newtonian free jets, subject to the effects of surface tension and gravity, our model predicts oscillation of the major axis of the free surface elliptical cross section between perpendicular directions with distance down the jet, and drawdown of the cross section, in agreement with observed behavior. 15 refs.

  4. Experimental study on the 3D image reconstruction in a truncated Archimedean-like spiral geometry with a long-rectangular detector and its image characteristics

    NASA Astrophysics Data System (ADS)

    Hong, Daeki; Cho, Heemoon; Cho, Hyosung; Choi, Sungil; Je, Uikyu; Park, Yeonok; Park, Chulkyu; Lim, Hyunwoo; Park, Soyoung; Woo, Taeho

    2015-11-01

    In this work, we performed a feasibility study on the three-dimensional (3D) image reconstruction in a truncated Archimedean-like spiral geometry with a long-rectangular detector for application to high-accurate, cost-effective dental x-ray imaging. Here an x-ray tube and a detector rotate together around the rotational axis several times and, concurrently, the detector moves horizontally in the detector coordinate at a constant speed to cover the whole imaging volume during the projection data acquisition. We established a table-top setup which mainly consists of an x-ray tube (60 kVp, 5 mA), a narrow CMOS-type detector (198-?m pixel resolution, 184 (W)×1176 (H) pixel dimension), and a rotational stage for sample mounting and performed a systematic experiment to demonstrate the viability of the proposed approach to volumetric dental imaging. For the image reconstruction, we employed a compressed-sensing (CS)-based algorithm, rather than a common filtered-backprojection (FBP) one, for more accurate reconstruction. We successfully reconstructed 3D images of considerably high quality and investigated the image characteristics in terms of the image value profile, the contrast-to-noise ratio (CNR), and the spatial resolution.

  5. Modelling of 3D fractured geological systems - technique and application

    NASA Astrophysics Data System (ADS)

    Cacace, M.; Scheck-Wenderoth, M.; Cherubini, Y.; Kaiser, B. O.; Bloecher, G.

    2011-12-01

    All rocks in the earth's crust are fractured to some extent. Faults and fractures are important in different scientific and industry fields comprising engineering, geotechnical and hydrogeological applications. Many petroleum, gas and geothermal and water supply reservoirs form in faulted and fractured geological systems. Additionally, faults and fractures may control the transport of chemical contaminants into and through the subsurface. Depending on their origin and orientation with respect to the recent and palaeo stress field as well as on the overall kinematics of chemical processes occurring within them, faults and fractures can act either as hydraulic conductors providing preferential pathways for fluid to flow or as barriers preventing flow across them. The main challenge in modelling processes occurring in fractured rocks is related to the way of describing the heterogeneities of such geological systems. Flow paths are controlled by the geometry of faults and their open void space. To correctly simulate these processes an adequate 3D mesh is a basic requirement. Unfortunately, the representation of realistic 3D geological environments is limited by the complexity of embedded fracture networks often resulting in oversimplified models of the natural system. A technical description of an improved method to integrate generic dipping structures (representing faults and fractures) into a 3D porous medium is out forward. The automated mesh generation algorithm is composed of various existing routines from computational geometry (e.g. 2D-3D projection, interpolation, intersection, convex hull calculation) and meshing (e.g. triangulation in 2D and tetrahedralization in 3D). All routines have been combined in an automated software framework and the robustness of the approach has been tested and verified. These techniques and methods can be applied for fractured porous media including fault systems and therefore found wide applications in different geo-energy related topics including CO2 storage in deep saline aquifers, shale gas extraction and geothermal heat recovery. The main advantage is that dipping structures can be integrated into a 3D body representing the porous media and the interaction between the discrete flow paths through and across faults and fractures and within the rock matrix can be correctly simulated. In addition the complete workflow is captured by open-source software.

  6. New constraints on the geometry and evolution of the Southern San Andreas Fault and Salton Pull-apart basin

    NASA Astrophysics Data System (ADS)

    Sahakian, V. J.; Holmes, J. J.; Kell, A. M.; Harding, A. J.; Driscoll, N. W.; Kent, G.

    2013-12-01

    In the recent geologic past, the Salton pull-apart basin, northern Imperial Fault (IF) and Southern San Andreas Fault (SSAF) have been part of an evolving tectonic regime, subject to strain partitioning. This part of the North American/Pacific plate boundary has the potential for generating a large earthquake. Several lines of active-source seismic reflection and refraction data in the Salton Sea were analyzed to better understand the fault interactions and evolution in this region by investigating the SSAF geometry, stratigraphy, and velocity structure. These data, collected in conjunction with the Salton Seismic Imaging Project (SSIP) include two fault-perpendicular lines: one adjacent to the southern terminus of the SSAF (Line 7), and one just south of the terminus (Line 8). We present results from Multi Channel Seismic (MCS) data along Line 7, and refraction data along Lines 7 and 8. Velocity models along these lines were constructed from the refraction data. Included in the Line 7 model is an interface representing a strong reflector observed in the MCS data, which helps to constrain the raypaths and velocities in the model. Line 7 MCS data image stratigraphic layers thickening to and dipping down to the east towards the SSAF, indicative of a westward-dipping, oblique strike-slip fault. The refraction data along this line are consistent with a westward dipping SSAF and a down the west normal component. We present velocity models for Line 7 and 8, as well as resolution tests supporting the fault's geometry. The results from these two lines and a fault parallel line suggest that the SSAF is dipping to the west and is in transtension. We propose that the SSAF has migrated northward through time, partitioning its strain onto the IF. As the IF migrates northwards it forms the Salton pull-apart basin.

  7. Palacios field: A 3-D case history

    SciTech Connect

    McWhorter, R.; Torguson, B.

    1994-12-31

    In late 1992, Mitchell Energy Corporation acquired a 7.75 sq mi (20.0 km{sup 2}) 3-D seismic survey over Palacios field. Matagorda County, Texas. The company shot the survey to help evaluate the field for further development by delineating the fault pattern of the producing Middle Oligocene Frio interval. They compare the mapping of the field before and after the 3-D survey. This comparison shows that the 3-D volume yields superior fault imaging and interpretability compared to the dense 2-D data set. The problems with the 2-D data set are improper imaging of small and oblique faults and insufficient coverage over a complex fault pattern. Whereas the 2-D data set validated a simple fault model, the 3-D volume revealed a more complex history of faulting that includes three different fault systems. This discovery enabled them to reconstruct the depositional and structural history of Palacios field.

  8. A free software for pore-scale modelling: solving Stokes equation for velocity fields and permeability values in 3D pore geometries

    NASA Astrophysics Data System (ADS)

    Gerke, Kirill; Vasilyev, Roman; Khirevich, Siarhei; Karsanina, Marina; Collins, Daniel; Korost, Dmitry; Mallants, Dirk

    2015-04-01

    In this contribution we introduce a novel free software which solves the Stokes equation to obtain velocity fields for low Reynolds-number flows within externally generated 3D pore geometries. Provided with velocity fields, one can calculate permeability for known pressure gradient boundary conditions via Darcy's equation. Finite-difference schemes of 2nd and 4th order of accuracy are used together with an artificial compressibility method to iteratively converge to a steady-state solution of Stokes' equation. This numerical approach is much faster and less computationally demanding than the majority of open-source or commercial softwares employing other algorithms (finite elements/volumes, lattice Boltzmann, etc.) The software consists of two parts: 1) a pre and post-processing graphical interface, and 2) a solver. The latter is efficiently parallelized to use any number of available cores (the speedup on 16 threads was up to 10-12 depending on hardware). Due to parallelization and memory optimization our software can be used to obtain solutions for 300x300x300 voxels geometries on modern desktop PCs. The software was successfully verified by testing it against lattice Boltzmann simulations and analytical solutions. To illustrate the software's applicability for numerous problems in Earth Sciences, a number of case studies have been developed: 1) identifying the representative elementary volume for permeability determination within a sandstone sample, 2) derivation of permeability/hydraulic conductivity values for rock and soil samples and comparing those with experimentally obtained values, 3) revealing the influence of the amount of fine-textured material such as clay on filtration properties of sandy soil. This work was partially supported by RSF grant 14-17-00658 (pore-scale modelling) and RFBR grants 13-04-00409-a and 13-05-01176-a.

  9. Initiation of deformation of the Eastern California Shear Zone: Constraints from Garlock fault geometry and GPS observations

    USGS Publications Warehouse

    Gan, Weijun; Zhang, P.; Shen, Z.-K.; Prescott, W.H.; Svarc, J.L.

    2003-01-01

    We suggest a 2-stage deformation model for the Eastern California Shear Zone (ECSZ) to explain the geometry of the Garlock fault trace. We assume the Garlock fault was originally straight and then was gradually curved by right-lateral shear deformation across the ECSZ. In our 2-stage deformation model, the first stage involves uniform shear deformation across the eastern part of the shear zone, and the second stage involves uniform shear deformation across the entire shear zone. In addition to the current shape of the Garlock fault, our model incorporates constraints on contemporary deformation rates provided by GPS observations. We find that the best fitting age for initiation of shear in eastern part of the ECSZ is about 5.0 ?? 0.4 Ma, and that deformation of the western part started about 1.6 Myr later.

  10. 3D Reconstruction of Chick Embryo Vascular Geometries Using Non-invasive High-Frequency Ultrasound for Computational Fluid Dynamics Studies.

    PubMed

    Tan, Germaine Xin Yi; Jamil, Muhammad; Tee, Nicole Gui Zhen; Zhong, Liang; Yap, Choon Hwai

    2015-11-01

    Recent animal studies have provided evidence that prenatal blood flow fluid mechanics may play a role in the pathogenesis of congenital cardiovascular malformations. To further these researches, it is important to have an imaging technique for small animal embryos with sufficient resolution to support computational fluid dynamics studies, and that is also non-invasive and non-destructive to allow for subject-specific, longitudinal studies. In the current study, we developed such a technique, based on ultrasound biomicroscopy scans on chick embryos. Our technique included a motion cancelation algorithm to negate embryonic body motion, a temporal averaging algorithm to differentiate blood spaces from tissue spaces, and 3D reconstruction of blood volumes in the embryo. The accuracy of the reconstructed models was validated with direct stereoscopic measurements. A computational fluid dynamics simulation was performed to model fluid flow in the generated construct of a Hamburger-Hamilton (HH) stage 27 embryo. Simulation results showed that there were divergent streamlines and a low shear region at the carotid duct, which may be linked to the carotid duct's eventual regression and disappearance by HH stage 34. We show that our technique has sufficient resolution to produce accurate geometries for computational fluid dynamics simulations to quantify embryonic cardiovascular fluid mechanics. PMID:26014359

  11. 3D non-Planar Finite Difference Dynamic Rupture: Application to the Landers Earthquake

    NASA Astrophysics Data System (ADS)

    Cruz-Atienza, V. M.; Virieux, J.; Aochi, H.; Peyrat, S.

    2004-12-01

    Many aspects of seismic complexity have been explained in the last thirty years thanks to the development of numerical approaches allowing seismologists to simulate the dynamic rupture of earthquakes. Heterogeneities in both the initial stress field and the surrounding medium are extremely important elements. The constitutive law describing the physics of the breakdown process which relates the fault friction to fault kinematics is also determinant. However, given the increasing amount of high quality seismological data, more sophisticated approaches are needed to explain observations so that others important physical factors, such as the real fault geometry, could be integrated into simulations. Bearing in mind these new high quality observations along with the current computational power, a great interest has arisen in the last five years to develop 3D numerical codes to simulate earthquakes with real fault geometries. Recently, Cruz-Atienza and Virieux (2004) have introduced a 2D finite difference (FD) approach for modeling the dynamic rupture of non-planar faults. In this work we analyze the 3D extension of such an approach. On that account, the new 3D code may consider arbitrary heterogeneous media, composite friction laws and non-planar fault geometries. The numerical criteria for rupture boundary conditions to model rupture processes accurately were determined experimentally finding consistency with those determined for the 2D case: the source is discretized by a set of numerical cells. Given a spatial grid step for wave propagation, the number of grid nodes contained in each cell should be adapted accordingly. The smaller the spatial step the greater the number of nodes. We have performed dynamic rupture simulations for different curved 3D faults and compared results with those given by a BIE method (Aochi et al., 2000). Consistency between solutions yielded by different numerical approaches is essential since it is the only way to have confidence in these kinds of complex simulations for which no theoretical solutions are available. This benchmarking exercise has also allowed us to better understand and quantify the effect of fault curvature on near-source seismograms and fault solutions. Finally, we applied our numerical approach to model the 1992 Landers earthquake (Mw=7.3). Several simulations were carried out including a heterogeneous initial stress field, layered elastic medium and the non-planar fault trace geometry. Complexity in near-field seismograms enhances the importance of both a heterogeneous surrounding medium and non-planar fault geometry due to their intimate interaction during rupture process. Aochi, H., E. Fukuyama and M. Matsu'ura, 2000, Pure. Appl. Geophys., 157, 2003-2027. Cruz-Atienza, V.M. and J. Virieux, 2004, Geophys. J. Int., 158, 939-954.

  12. The 3-D Tectonic Crustal Stress Field and Style of Faulting Along the Pacific North America Plate Boundary in Southern California

    NASA Astrophysics Data System (ADS)

    Yang, W.; Hauksson, E.

    2012-12-01

    We invert for the state of stress in the southern California crust using recent high quality earthquake focal mechanisms catalog (1981-2010). To interpret the stress field we determine the maximum horizontal compressive stress (SHmax) orientations and the style of faulting across southern California at four different scales of resolution, with grid spacing of 5 and 10 km, and with 15 or 30 events per grid. The stress field is best resolved where seismicity rates are high but sufficient data are available to constrain the stress field across most of the region. The trend of SHmax exhibits significant regional and local spatial heterogeneities. The regional trend of SHmax varies from north along the San Andreas system to NNE to the east in the Eastern California Shear Zone as well as to the west, within the Continental Borderland and the western Transverse Ranges. The transition zones from one state of stress to the other are very sharp and occur over a distance of a few kilometers, following a trend from Yucca Valley to Imperial Valley to the east, and the western edge of the Peninsular Ranges to the west. The local scale heterogeneities in the SHmax trend include NNW trends along the San Andreas Fault near Cajon Pass, Tejon Pass, and the Cucapa Range, as well as NNE trends near the northern San Jacinto Fault and the Wheeler Ridge region. The style of faulting exhibits similar complexity, ranging from predominantly normal faulting in the high Sierra Nevada, to strike-slip faulting along the San Andreas system, to three consecutive bands of thrust faulting in the Wheeler Ridge area and the western Transfer Ranges. The local variations in the style of faulting include normal faulting at the north end of the San Jacinto Fault and scattered regions of thrust faulting. We compare the pattern of SHmax trend in the crust with the GPS measured maximum shortening strain rate tensor and upper mantle anisotropy. The regional variations in the SHmax trends are very similar to the pattern of the maximum shortening axes of surface strain rate tensor field although the strain filed tends to be smoother and appears to capture some of the upper mantle deformation field. The mean trend of SHmax depart about approximately 14° to the east from the trend of the maximum shortening directions of anisotropy in the upper mantle.tacked SHmax profile across the Cajon Pass from the Continental Borderland to the Basin and Range. GPS velocity profile is in cyan.

  13. Fault growth and interactions in a multiphase rift fault network: Horda Platform, Norwegian North Sea

    NASA Astrophysics Data System (ADS)

    Duffy, Oliver B.; Bell, Rebecca E.; Jackson, Christopher A.-L.; Gawthorpe, Rob L.; Whipp, Paul S.

    2015-11-01

    Physical models predict that multiphase rifts that experience a change in extension direction between stretching phases will typically develop non-colinear normal fault sets. Furthermore, multiphase rifts will display a greater frequency and range of styles of fault interactions than single-phase rifts. Although these physical models have yielded useful information on the evolution of fault networks in map view, the true 3D geometry of the faults and associated interactions are poorly understood. Here, we use an integrated 3D seismic reflection and borehole dataset to examine a range of fault interactions that occur in a natural multiphase fault network in the northern Horda Platform, northern North Sea. In particular we aim to: i) determine the range of styles of fault interaction that occur between non-colinear faults; ii) examine the typical geometries and throw patterns associated with each of these different styles; and iii) highlight the differences between single-phase and multiphase rift fault networks. Our study focuses on a ca. 350 km2 region around the >60 km long, N-S-striking Tusse Fault, a normal fault system that was active in the Permian-Triassic and again in the Late Jurassic-to-Early Cretaceous. The Tusse Fault is one of a series of large (>1500 m throw) N-S-striking faults forming part of the northern Horda Platform fault network, which includes numerous smaller (2-10 km long), lower throw (<100 m), predominantly NW-SE-striking faults that were only active during the Late Jurassic to Early Cretaceous. We examine how the 2nd-stage NW-SE-striking faults grew, interacted and linked with the N-S-striking Tusse Fault, documenting a range of interaction styles including mechanical and kinematic isolation, abutment, retardation and reactivated relays. Our results demonstrate that: i) isolated, and abutting interactions are the most common fault interaction styles in the northern Horda Platform; ii) pre-existing faults can act as sites of nucleation for 2nd-stage faults or may form mechanical barriers to propagation; iii) the throw distribution on reactivated 1st-stage faults will be modified in a predictable manner if they are intersected or influenced by 2nd-stage faults; iv) sites of fault linkage and relay-breaching associated with the first phase of extension can act as preferential nucleation sites for 2nd-stage faults; and v) the development of fault intersections is a dynamic process, involving the gradual transition from one style to another.

  14. Near-surface location, geometry, and velocities of the Santa Monica Fault Zone, Los Angeles, California

    USGS Publications Warehouse

    Catchings, R.D.; Gandhok, G.; Goldman, M.R.; Okaya, D.; Rymer, M.J.; Bawden, G.W.

    2008-01-01

    High-resolution seismic-reflection and seismic-refraction imaging, combined with existing borehole, earthquake, and paleoseismic trenching data, suggest that the Santa Monica fault zone in Los Angeles consists of multiple strands from several kilometers depth to the near surface. We interpret our seismic data as showing two shallow-depth low-angle fault strands and multiple near-vertical (???85??) faults in the upper 100 m. One of the low-angle faults dips northward at about 28?? and approaches the surface at the base of a topographic scarp on the grounds of the Wadsworth VA Hospital (WVAH). The other principal low-angle fault dips northward at about 20?? and projects toward the surface about 200 m south of the topographic scarp, near the northernmost areas of the Los Angeles Basin that experienced strong shaking during the 1994 Northridge earthquake. The 20?? north-dipping low-angle fault is also apparent on a previously published seismic-reflection image by Pratt et al. (1998) and appears to extend northward to at least Wilshire Boulevard, where the fault may be about 450 m below the surface. Slip rates determined at the WVAH site could be significantly underestimated if it is assumed that slip occurs only on a single strand of the Santa Monica fault or if it is assumed that the near-surface faults dip at angles greater than 20-28??. At the WVAH, tomographic velocity modeling shows a significant decrease in velocity across near-surface strands of the Santa Monica fault. P-wave velocities range from about 500 m/sec at the surface to about 4500 m/sec within the upper 50 m on the north side of the fault zone at WVAH, but maximum measured velocities on the south side of the low-angle fault zone at WVAH are about 3500 m/sec. These refraction velocities compare favorably with velocities measured in nearby boreholes by Gibbs et al. (2000). This study illustrates the utility of com- bined seismic-reflection and seismic-refraction methods, which allow more accurate reflection imaging and compositional estimations across areas with highly variable velocities, a property that is characteristic of most fault zones.

  15. Extrapolating subsurface geometry by surface expressions in transpressional strike slip fault, deduced from analogue experiments with settings of rheology and convergence angle

    NASA Astrophysics Data System (ADS)

    Hsieh, Shang Yu; Neubauer, Franz

    2015-04-01

    The internal structure of major strike-slip faults is still poorly understood, particularly how to extrapolate subsurface structures by surface expressions. Series of brittle analogue experiments by Leever et al., 2011 resulted the convergence angle is the most influential factor for surface structures. Further analogue models with different ductile settings allow a better understanding in extrapolating surface structures to the subsurface geometry of strike-slip faults. Fifteen analogue experiments were constructed to represent strike-slip faults in nature in different geological settings. As key parameters investigated in this study include: (a) the angle of convergence, (b) the thickness of brittle layer, (c) the influence of a rheological weak layer within the crust, and (d) influence of a thick and rheologically weak layer at the base of the crust. The experiments are aimed to explain first order structures along major transcurrent strike-slip faults such as the Altyn, Kunlun, San Andrea and Greendale (Darfield earthquake 2010) faults. The preliminary results show that convergence angle significantly influences the overall geometry of the transpressional system with greater convergence angles resulting in wider fault zones and higher elevation. Different positions, densities and viscosities of weak rheological layers have not only different surface expressions but also affect the fault geometry in the subsurface. For instance, rheological weak material in the bottom layer results in stretching when experiment reaches a certain displacement and a buildup of a less segmented, wide positive flower structure. At the surface, a wide fault valley in the middle of the fault zone is the reflection of stretching along the velocity discontinuity at depth. In models with a thin and rheologically weaker layer in the middle of the brittle layer, deformation is distributed over more faults and the geometry of the fault zone below and above the weak zone shows significant differences, suggesting that the correlation of structures across a weak layer has to be supported by geophysical data, which help constraining the geometry of the deep part. This latter experiment has significantly similar phenomena in reality, such as few pressure ridges along Altyn fault. The experimental results underline the need to understand the role of the convergence angle and the influence of rheology on fault evolution, in order to connect between surface deformation and subsurface geometry.

  16. Controlled Fabrication of Microparticles with Complex 3D Geometries by Tunable Interfacial Deformation of Confined Polymeric Fluids in 2D Micromolds.

    PubMed

    Choi, Chang-Hyung; Lee, Byungjin; Kim, Jongmin; Nam, Jin-Oh; Yi, Hyunmin; Lee, Chang-Soo

    2015-06-01

    Polymeric microparticles with complex shapes have attracted substantial attention in many application areas because particle shape is a critical parameter to impart programmable functionalities. The formation of specific three-dimensional (3D) microstructures in a simple, scalable, and controllable manner is difficult. Here, we report the controlled fabrication of microparticles with complex 3D shapes based on the simple tuning of mold swelling and capillarity. Specifically, a photocurable solution loaded in micromolds is spatially deformed into complex shapes depending on the degree of molding swelling and capillarity, thereby producing polymeric microparticles with controlled 3D shapes upon photopolymerization. The results show that highly uniform microparticles with controlled two-dimensional (2D) and 3D shapes were fabricated from identical 2D micromolds via the simple tuning of the wetting fluids. This technique can be extended to produce highly complex microarchitectures with controlled 3D geometric domains via 2D mold designs. Finally, multicompartment microparticles with independently controlled 3D shapes for each compartment are produced by a simple combination of fabrication sequences. We envision that this strategy of producing 3D microarchitectures from easily designed simple micromolds could provide a path to new materials and new properties. PMID:25920947

  17. Large-scale geometry, oset and kinematic evolution of the Karakorum fault, Tibet

    E-print Network

    Lacassin, Robin

    eastwards, as a transpressive flower structure, along the Indus^Tsangpo suture. Our new data thus suggest the edge of the Tarim, the Altyn Tagh fault also ap- pears to cut the lithosphere (e.g. [3]) and contrib

  18. Transfer zones in listric normal fault systems

    NASA Astrophysics Data System (ADS)

    Bose, Shamik

    Listric normal faults are common in passive margin settings where sedimentary units are detached above weaker lithological units, such as evaporites or are driven by basal structural and stratigraphic discontinuities. The geometries and styles of faulting vary with the types of detachment and form landward and basinward dipping fault systems. Complex transfer zones therefore develop along the terminations of adjacent faults where deformation is accommodated by secondary faults, often below seismic resolution. The rollover geometry and secondary faults within the hanging wall of the major faults also vary with the styles of faulting and contribute to the complexity of the transfer zones. This study tries to understand the controlling factors for the formation of the different styles of listric normal faults and the different transfer zones formed within them, by using analog clay experimental models. Detailed analyses with respect to fault orientation, density and connectivity have been performed on the experiments in order to gather insights on the structural controls and the resulting geometries. A new high resolution 3D laser scanning technology has been introduced to scan the surfaces of the clay experiments for accurate measurements and 3D visualizations. Numerous examples from the Gulf of Mexico have been included to demonstrate and geometrically compare the observations in experiments and real structures. A salt cored convergent transfer zone from the South Timbalier Block 54, offshore Louisiana has been analyzed in detail to understand the evolutionary history of the region, which helps in deciphering the kinematic growth of similar structures in the Gulf of Mexico. The dissertation is divided into three chapters, written in a journal article format, that deal with three different aspects in understanding the listric normal fault systems and the transfer zones so formed. The first chapter involves clay experimental models to understand the fault patterns in divergent and convergent transfer zones. Flat base plate setups have been used to build different configurations that would lead to approaching, normal offset and overlapping faults geometries. The results have been analyzed with respect to fault orientation, density, connectivity and 3D geometry from photographs taken from the three free surfaces and laser scans of the top surface of the clay cake respectively. The second chapter looks into the 3D structural analysis of the South Timbalier Block 54, offshore Louisiana in the Gulf of Mexico with the help of a 3D seismic dataset and associated well tops and velocity data donated by ExxonMobil Corporation. This study involves seismic interpretation techniques, velocity modeling, cross section restoration of a series of seismic lines and 3D subsurface modeling using depth converted seismic horizons, well tops and balanced cross sections. The third chapter deals with the clay experiments of listric normal fault systems and tries to understand the controls on geometries of fault systems with and without a ductile substrate. Sloping flat base plate setups have been used and silicone fluid underlain below the clay cake has been considered as an analog for salt. The experimental configurations have been varied with respect to three factors viz. the direction of slope with respect to extension, the termination of silicone polymer with respect to the basal discontinuities and overlap of the base plates. The analyses for the experiments have again been performed from photographs and 3D laser scans of the clay surface.

  19. Self-Calibration of Cone-Beam CT Geometry Using 3D-2D Image Registration: Development and Application to Task-Based Imaging with a Robotic C-Arm

    PubMed Central

    Ouadah, S.; Stayman, J. W.; Gang, G.; Uneri, A.; Ehtiati, T.; Siewerdsen, J. H.

    2015-01-01

    Purpose Robotic C-arm systems are capable of general noncircular orbits whose trajectories can be driven by the particular imaging task. However obtaining accurate calibrations for reconstruction in such geometries can be a challenging problem. This work proposes a method to perform a unique geometric calibration of an arbitrary C-arm orbit by registering 2D projections to a previously acquired 3D image to determine the transformation parameters representing the system geometry. Methods Experiments involved a cone-beam CT (CBCT) bench system, a robotic C-arm, and three phantoms. A robust 3D-2D registration process was used to compute the 9 degree of freedom (DOF) transformation between each projection and an existing 3D image by maximizing normalized gradient information with a digitally reconstructed radiograph (DRR) of the 3D volume. The quality of the resulting “self-calibration” was evaluated in terms of the agreement with an established calibration method using a BB phantom as well as image quality in the resulting CBCT reconstruction. Results The self-calibration yielded CBCT images without significant difference in spatial resolution from the standard (“true”) calibration methods (p-value >0.05 for all three phantoms), and the differences between CBCT images reconstructed using the “self” and “true” calibration methods were on the order of 10?3 mm?1. Maximum error in magnification was 3.2%, and back-projection ray placement was within 0.5 mm. Conclusion The proposed geometric “self” calibration provides a means for 3D imaging on general non-circular orbits in CBCT systems for which a geometric calibration is either not available or not reproducible. The method forms the basis of advanced “task-based” 3D imaging methods now in development for robotic C-arms. PMID:26388661

  20. Self-calibration of cone-beam CT geometry using 3D-2D image registration: development and application to tasked-based imaging with a robotic C-arm

    NASA Astrophysics Data System (ADS)

    Ouadah, S.; Stayman, J. W.; Gang, G.; Uneri, A.; Ehtiati, T.; Siewerdsen, J. H.

    2015-03-01

    Purpose: Robotic C-arm systems are capable of general noncircular orbits whose trajectories can be driven by the particular imaging task. However obtaining accurate calibrations for reconstruction in such geometries can be a challenging problem. This work proposes a method to perform a unique geometric calibration of an arbitrary C-arm orbit by registering 2D projections to a previously acquired 3D image to determine the transformation parameters representing the system geometry. Methods: Experiments involved a cone-beam CT (CBCT) bench system, a robotic C-arm, and three phantoms. A robust 3D-2D registration process was used to compute the 9 degree of freedom (DOF) transformation between each projection and an existing 3D image by maximizing normalized gradient information with a digitally reconstructed radiograph (DRR) of the 3D volume. The quality of the resulting "self-calibration" was evaluated in terms of the agreement with an established calibration method using a BB phantom as well as image quality in the resulting CBCT reconstruction. Results: The self-calibration yielded CBCT images without significant difference in spatial resolution from the standard ("true") calibration methods (p-value >0.05 for all three phantoms), and the differences between CBCT images reconstructed using the "self" and "true" calibration methods were on the order of 10-3 mm-1. Maximum error in magnification was 3.2%, and back-projection ray placement was within 0.5 mm. Conclusion: The proposed geometric "self" calibration provides a means for 3D imaging on general noncircular orbits in CBCT systems for which a geometric calibration is either not available or not reproducible. The method forms the basis of advanced "task-based" 3D imaging methods now in development for robotic C-arms.

  1. Subsurface Geometry of the Sani-Chelungpu Faults and Fold Scarp Formation in the 1999 Chi-Chi Taiwan Earthquake

    NASA Astrophysics Data System (ADS)

    Hung, J.; Suppe, J.

    2002-12-01

    A set of detailed cross sections reveal three-dimensional ramp-flat geometry of the Sani and Chelungpu faults in central Taiwan, where the Chi-Chi earthquake occurred. Along the Choshui River, the Chelungpu fault dips toward the east at 30o-40 o and detached at a depth of 10 km. Along with decreasing ramp-dip to 20o-25 o, the decollement changes from 10 km northward to 6 km deep in the Chungliao section, an average 32o dip toward south in 6 km distance. The decollement lies at a roughly constant depth of 6-7 km from Chungliao northward to the Wufeng­VKuoshing section, where it steps from 6 km to 3 km deep in the Fengyuan-Tamaopu section (average 8 o dip toward south). About 10 km north of Fengyuan, drilling wells show that the Chelungpu fault lies less than 1 km along the Taan River (average 10 o dip). South of Wufeng, the Chelungpu-Sani fault emplaced the Pliocene Chinshu Shale ontop the Pleistocene Toukoushan Formation; whereas in the north, the Sani thrust imbrcates from the Chelungpu fault and cuts down-section northward. North from the Taan River, the late Quaternary Tungshih anticline in the hanging-wall of the Sani thrust localizes the surface ruptures and grows during the Chi-Chi earthquake. Fold scarps of the Chi-Chi earthquake appear in the Ailiao village (east of Tsaotun), Hsintse folded terrace, and western limb of the Tungshih antcilne. They are developed associated with coseismic fault-bend folding. Applying a schematic relationship between fault slip, folding vector and height, width and dip of fold scarp as well as terrace dating and geodetic data to the Shuichin (ele. 600m) and Dana (ele. 500m) terraces in the Hsintse area, a geologic slip rate of 5 mm/yr, or a minimum of 38 Chi-Chi equivalent earthquakes is needed to form the 100m-high fold scarp. Results of comparing coseismic and finite excess area in the Tungshih anticline show that Quaternary structures in the north of the Taan River are relatively younger than terraces in the Hsintse area.

  2. 3D fluid-structure modelling and vibration analysis for fault diagnosis of Francis turbine using multiple ANN and multiple ANFIS

    NASA Astrophysics Data System (ADS)

    Saeed, R. A.; Galybin, A. N.; Popov, V.

    2013-01-01

    This paper discusses condition monitoring and fault diagnosis in Francis turbine based on integration of numerical modelling with several different artificial intelligence (AI) techniques. In this study, a numerical approach for fluid-structure (turbine runner) analysis is presented. The results of numerical analysis provide frequency response functions (FRFs) data sets along x-, y- and z-directions under different operating load and different position and size of faults in the structure. To extract features and reduce the dimensionality of the obtained FRF data, the principal component analysis (PCA) has been applied. Subsequently, the extracted features are formulated and fed into multiple artificial neural networks (ANN) and multiple adaptive neuro-fuzzy inference systems (ANFIS) in order to identify the size and position of the damage in the runner and estimate the turbine operating conditions. The results demonstrated the effectiveness of this approach and provide satisfactory accuracy even when the input data are corrupted with certain level of noise.

  3. Primal 3D MRI

    E-print Network

    Kim, Panki

    ANATOMY.TV #12;- Primal 3D . 3D , , , , , , , MRI - , , , , - , , , , - , 3D Anatomy.TV #12;3D ATLAS #12;Home #12;3D ATLAS - 1 3D -Anatomy: 3D - MRI: MRI Anatomy - Slides: - Movies: #12;3D ATLAS - 2 Layers

  4. Virtual California: Earthquake Statistics, Surface Deformation Patterns, Surface Gravity Changes and InSAR Interferograms for Arbitrary Fault Geometries

    NASA Astrophysics Data System (ADS)

    Schultz, K.; Sachs, M. K.; Heien, E. M.; Rundle, J. B.; Fernandez, J.; Turcotte, D.; Donnellan, A.

    2014-12-01

    With the ever increasing number of geodetic monitoring satellites, it is vital to have a variety of geophysical numerical simulators to produce sample/model datasets. Just as hurricane forecasts are derived from the consensus among multiple atmospheric models, earthquake forecasts cannot be derived from a single comprehensive model. Here we present the functionality of Virtual California, a numerical simulator that can generate sample surface deformations, surface gravity changes, and InSAR interferograms in addition to producing earthquake statistics and forecasts.Virtual California is a boundary element code designed to explore the seismicity of today's fault systems. For arbitrary input fault geometry, Virtual California can output simulated seismic histories of 50,000 years or more. Using co-seismic slips from the output data, we generate surface deformation maps, surface gravity change maps, and InSAR interferograms as viewed by an orbiting satellite. Furthermore, using the times between successive earthquakes we generate probability distributions and earthquake forecasts.Virtual California is now supported by the Computational Infrastructure for Geodynamics. The source code is available for download and it comes with a users' manual. The manual includes instructions on how to generate fault models from scratch, how to deploy the simulator across a parallel computing environment, etc.http://geodynamics.org/cig/software/vc/

  5. The first systematic analysis of 3D rapid prototyped poly(?-caprolactone) scaffolds manufactured through BioCell printing: the effect of pore size and geometry on compressive mechanical behaviour and in vitro hMSC viability.

    PubMed

    Domingos, M; Intranuovo, F; Russo, T; De Santis, R; Gloria, A; Ambrosio, L; Ciurana, J; Bartolo, P

    2013-12-01

    Novel additive manufacturing processes are increasingly recognized as ideal techniques to produce 3D biodegradable structures with optimal pore size and spatial distribution, providing an adequate mechanical support for tissue regeneration while shaping in-growing tissues. With regard to the mechanical and biological performances of 3D scaffolds, pore size and geometry play a crucial role. In this study, a novel integrated automated system for the production and in vitro culture of 3D constructs, known as BioCell Printing, was used only to manufacture poly(?-caprolactone) scaffolds for tissue engineering; the influence of pore size and shape on their mechanical and biological performances was investigated. Imposing a single lay-down pattern of 0°/90° and varying the filament distance, it was possible to produce scaffolds with square interconnected pores with channel sizes falling in the range of 245-433 µm, porosity 49-57% and a constant road width. Three different lay-down patterns were also adopted (0°/90°, 0°/60/120° and 0°/45°/90°/135°), thus resulting in scaffolds with quadrangular, triangular and complex internal geometries, respectively. Mechanical compression tests revealed a decrease of scaffold stiffness with the increasing porosity and number of deposition angles (from 0°/90° to 0°/45°/90°/135°). Results from biological analysis, carried out using human mesenchymal stem cells, suggest a strong influence of pore size and geometry on cell viability. On the other hand, after 21 days of in vitro static culture, it was not possible to detect any significant variation in terms of cell morphology promoted by scaffold topology. As a first systematic analysis, the obtained results clearly demonstrate the potential of the BioCell Printing process to produce 3D scaffolds with reproducible well organized architectures and tailored mechanical properties. PMID:24192056

  6. Fab trees for designing complex 3D printable materials

    E-print Network

    Wang, Ye, M. Eng. Massachusetts Institute of Technology

    2013-01-01

    With more 3D printable materials being invented, 3D printers nowadays could replicate not only geometries, but also appearance and physical properties. On the software side, the tight coupling between geometry and material ...

  7. Quantitative Process of CAOB Orogeny: Insights into the Geometry and Kinematic Evolution of the Central Segment of Wu'erhe-Xiazijie Fault at the Northwestern Margin of Junggar Basin, China

    NASA Astrophysics Data System (ADS)

    He, Dengfa; Wu, Xiaozhi; ma, Delong

    2014-05-01

    How do the Central Asia Orogenic Belts (CAOB) accrete or propagate since the Carboniferous Period is a key issue to understand its orogenic style and evolution processes. To make use of the new acquired seismic data, 2-D and 3-D, drilled cores and logging data, and surface geology at the Wu'erhe-Xiazijie thrust zone (WXTZ) at the northwestern margin of Junggar Basin, the paper studies the geometry and kinematics of the central segment of WXTZ. At the end of Carboniferous, it formed a fault-bend fold in the Carboniferous with the thrust fault (F1) soled into the intra-Carboniferous detachment zone and stepped-up to the surface and subjected to erosion, and thus with the very lowest Permian Jiamuhe Formation (P1j) unconformablly overlain it. The slip and horizontal shortening of F1 are 2.69km and 2.66km respectively. The second phase of thrusting was in the depositional stage of Early Permian Fengcheng Formation (P1f). By utilizing the old lower flat (F1) and a new upper detachment (F2) in the top Carboniferous it formed a tectonic wedge with a back-thrust fault developed in the overlying strata. The slip and horizontal shortening of the wedge are 9.93km and 9.43km respectively. Then it subsided and filled with thick-sediments till the earliest Triassic Period. The third phase of thrusting formed a meso-scale fault-bend fold in the Permian with the F2 as the lower detachment and the upper flat (F3) located at the base of Fengcheng Formation (P1f). The slip and horizontal shortening of the fault (F2 or F3) are the same as 4.48km. The fourth phase of thrusting took place at the latest Triassic, the fault (F4) cutoff F2 downwards and propagated upward into the upper Permian and formed a fault-propagation fold in the Triassic strata, with the fault-slip and horizontal shortening of 4.67km and 4.07km respectively. The fault-propagation fold is so-called Fengcheng anticline and a giant oil field nowadays. Besides thrusting of F4, the thrust faults, Wulanlinge( F5) and Da'erbut (F6) thrust also into the basin in a backward sequence at this time of period. Since Jurassic, it evolved into a quiescent period with the Jurassic, Cretaceous, and Paleogene strata upwardly onlapping the thrust zone. However, the Da'erbut Fault (F6) reactivated during the Late Neogene to the Quaternary. It showed a composite character of sinistral strike-slipping and reverse-faulting, which modified the structure of WXTZ. WXTZ shows episodic thrusting during Carboniferous to Triassic and exhibits a breaking-backward style with the fault-slip and horizontal shortening more than 21.74km and 20.64km respectively.

  8. Modelling of fractured geological systems: from scattered data to 3D Finite Element simulations

    NASA Astrophysics Data System (ADS)

    Cacace, Mauro; Blöcher, Mando Guido; Lewerenz, Björn; Zimmermann, Günther; Moeck, Inga

    2010-05-01

    To simulate processes occurring in fractured geological systems it is essential to capture the coupling of different active mechanisms within their realistic three dimensional geological environment. The complexity of fractured networks hampered a detailed representation of the real geometry often resulting in oversimplified models of the natural systems. The present paper describes a new approach to generating 3D meshes for realistic fault geometries embedded in layered geological systems. The method improves the integration of generic dipping structures into a 3D porous medium. This enables to simulate the coupling and interactions between discrete fractures and the rock matrix. The approach is automated by a C++ based source code and requires a minimum amount of information to be provided a priori. Input data are files of scattered data points describing the geometry of the geological model (layers' interfaces plus faults). Based on this information, 3D unstructured tetrahedral meshes are generated where faults of generic dipping are represented as 2D discrete surfaces within a 3D geological boundary volume. Formats of the output files are easily exported to existing software to simulate (T)hermal-(H)ydraulic-(M)echanical-(C)hemical processes by means of finite element or finite volume numerical techniques. Numerical simulations of coupled T-H processes for a relatively simple geometry (two layers cut by two crossing dipping faults) and for a real case geological setting (based on a simplified structural model of the GroßSchönebeck geothermal reservoir in northern Germany) are presented to show the reliability and robustness of the method.

  9. 3D photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Carson, Jeffrey J. L.; Roumeliotis, Michael; Chaudhary, Govind; Stodilka, Robert Z.; Anastasio, Mark A.

    2010-06-01

    Our group has concentrated on development of a 3D photoacoustic imaging system for biomedical imaging research. The technology employs a sparse parallel detection scheme and specialized reconstruction software to obtain 3D optical images using a single laser pulse. With the technology we have been able to capture 3D movies of translating point targets and rotating line targets. The current limitation of our 3D photoacoustic imaging approach is its inability ability to reconstruct complex objects in the field of view. This is primarily due to the relatively small number of projections used to reconstruct objects. However, in many photoacoustic imaging situations, only a few objects may be present in the field of view and these objects may have very high contrast compared to background. That is, the objects have sparse properties. Therefore, our work had two objectives: (i) to utilize mathematical tools to evaluate 3D photoacoustic imaging performance, and (ii) to test image reconstruction algorithms that prefer sparseness in the reconstructed images. Our approach was to utilize singular value decomposition techniques to study the imaging operator of the system and evaluate the complexity of objects that could potentially be reconstructed. We also compared the performance of two image reconstruction algorithms (algebraic reconstruction and l1-norm techniques) at reconstructing objects of increasing sparseness. We observed that for a 15-element detection scheme, the number of measureable singular vectors representative of the imaging operator was consistent with the demonstrated ability to reconstruct point and line targets in the field of view. We also observed that the l1-norm reconstruction technique, which is known to prefer sparseness in reconstructed images, was superior to the algebraic reconstruction technique. Based on these findings, we concluded (i) that singular value decomposition of the imaging operator provides valuable insight into the capabilities of a 3D photoacoustic imaging system, and (ii) that reconstruction algorithms which favor sparseness can significantly improve imaging performance. These methodologies should provide a means to optimize detector count and geometry for a multitude of 3D photoacoustic imaging applications.

  10. Magnetic Circular Dichroism in Resonant Raman Scattering in the Perpendicular Geometry at the L edge of 3d Transition Metal Systems

    SciTech Connect

    Braicovich, L.; Tagliaferri, A.; Dallera, C.; De Michelis, B.; Braicovich, L.; Tagliaferri, A.; De Michelis, B.; van der Laan, G.; Duerr, H.A.; Ghiringhelli, G.; Brookes, N.B.; van Veenendaal, M.A.; Chervinskii, M.M.

    1999-02-01

    We measured circular dichroism in resonant x-ray scattering 3d{sup n}{r_arrow}2p{sup 5}3d{sup n+1}{r_arrow}3s{sup 1}3d{sup n+1} with incidence perpendicular to the magnetization where the absorption dichroism vanishes. The advantages of photon scattering over other techniques make it possible to study a wide range of materials. The Ni L{sub 3} dichroism in NiFe{sub 2}O {sub 4} is (28{plus_minus}5){percent} in agreement with a localized model. In the metal Co the dichroism is reduced to (10.4{plus_minus}1){percent} (L{sub 3}) and (6.8{plus_minus}1.5){percent} (7.5 eV above L{sub 3} ), indicating a large sensitivity to the nature of the valence states despite the fact that this spectroscopy is based on inner shell transitions. {copyright} {ital 1999} {ital The American Physical Society }

  11. Oceanic transform earthquakes with unusual mechanisms or locations - Relation to fault geometry and state of stress in the adjacent lithosphere

    NASA Technical Reports Server (NTRS)

    Wolfe, Cecily J.; Bergman, Eric A.; Solomon, Sean C.

    1993-01-01

    Results are presented of a search for transform earthquakes departing from the pattern whereby they occur on the principal transform displacement zone (PTDZ) and have strike-slip mechanisms consistent with transform-parallel motion. The search was conducted on the basis of source mechanisms and locations taken from the Harvard centroid moment tensor catalog and the bulletin of the International Seismological Center. The source mechanisms and centroid depths of 10 such earthquakes on the St. Paul's, Marathon, Owen, Heezen, Tharp, Menard, and Rivera transforms are determined from inversions of long-period body waveforms. Much of the anomalous earthquake activity on oceanic transforms is associated with complexities in the geometry of the PTDZ or the presence of large structural features that may influence slip on the fault.

  12. Neotectonic reactivation of shear zones and implications for faulting style and geometry in the continental margin of NE Brazil

    NASA Astrophysics Data System (ADS)

    Bezerra, F. H. R.; Rossetti, D. F.; Oliveira, R. G.; Medeiros, W. E.; Neves, B. B. Brito; Balsamo, F.; Nogueira, F. C. C.; Dantas, E. L.; Andrades Filho, C.; Góes, A. M.

    2014-02-01

    The eastern continental margin of South America comprises a series of rift basins developed during the breakup of Pangea in the Jurassic-Cretaceous. We integrated high resolution aeromagnetic, structural and stratigraphic data in order to evaluate the role of reactivation of ductile, Neoproterozoic shear zones in the deposition and deformation of post-rift sedimentary deposits in one of these basins, the Paraíba Basin in northeastern Brazil. This basin corresponds to the last part of the South American continent to be separated from Africa during the Pangea breakup. Sediment deposition in this basin occurred in the Albian-Maastrichtian, Eocene-Miocene, and in the late Quaternary. However, our investigation concentrates on the Miocene-Quaternary, which we consider the neotectonic period because it encompasses the last stress field. This consisted of an E-W-oriented compression and a N-S-oriented extension. The basement of the basin forms a slightly seaward-tilted ramp capped by a late Cretaceous to Quaternary sedimentary cover ~ 100-400 m thick. Aeromagnetic lineaments mark the major steeply-dipping, ductile E-W- to NE-striking shear zones in this basement. The ductile shear zones mainly reactivated as strike-slip, normal and oblique-slip faults, resulting in a series of Miocene-Quaternary depocenters controlled by NE-, E-W-, and a few NW-striking faults. Faulting produced subsidence and uplift that are largely responsible for the present-day morphology of the valleys and tablelands in this margin. We conclude that Precambrian shear zone reactivation controlled geometry and orientation, as well as deformation of sedimentary deposits, until the Neogene-Quaternary.

  13. Future earthquake source faults on deep sea-floor around the Boso triple plate junction revealed by tectonic geomorphology using 3D images produced from 150 meter grid DEM

    NASA Astrophysics Data System (ADS)

    Goto, H.; Nakata, T.; Watanabe, M.; Suzuki, Y.; Izumi, N.; Nishizawa, A.; Horiuchi, D.; Kido, Y. N.

    2013-12-01

    Boso triple junction, which is the only example of a triple trench junction on earth, is located off the southeast of Boso peninsula, where the Izu-Bonin trench meets with the Japan trench and the Sagami trench. Boso submarine canyon, which is extended to Katsuuma basin about 7000m deep, forms an incised meander along the north side of Sagami trough. Taito spur separate Katsuuma basin from Bando abyssal basin about 9000m deep, where Japan trench meet with Isu-Bonin trench. In this paper, we present detailed stereo-paired topographic images produced from 0.002 degree (about 150m) DBEM (Digital Bathymetry Model), which processed from the depth sounding data obtained by Japan Coast Guard and JAMSTEC around Boso triple junction. It enables us to observe submarine geomorphology easily and precisely. We identified submarine active faults and other tectonic features related to subduction by using the similar standard for air-photo interpretation of inland active faults. We made more precise submarine active tectonic geomorphological map around Boso triple junction than that by previous workers. Numerous distinct faults on the so-called outer rise associated with subduction of Pacific plate are regarded as normal faulting as widely accepted. While the normal faults on the outer rise are parallel to the trench in the southern part of the Japan trench and the northern part of the Izu-Bonin trench, these normal faults around the east of the triple junction with NNW-SSE extend slightly oblique to the trench. The western margin of Bando abyssal basin is bounded by the thrust faults, which form east-facing 200-500m-high convex scarps associated with raised basin floor to the west of the scarp. These faults also deform Mogi submarine fan surface and uplift to the west along the extension of the scarp. The antecedent valley is extended for about 10km across Taito spur that is an active anticlinal ridge about 1000m high. Katsuura basin is surrounded by terraced former basin floor that is tilted to the west, indicating up-growing of Taito spur. Northeastern part of Izu bar on Philippine Sea plate is characterized by rather smooth extensive convex slope between 1500m-7500m for over 200km long along the trench. On the lower part of the slope below 6000m, several gullies such as Mikura canyon and Kita-Hachijo canyon dissecting the slope forms rapids, probably due to continuous up-warping by subsurface thrusting dipping to the west under the slope. It is noteworthy that we can identify prominent active tectonic features on even very deep sea-floor along the plate boundaries, by using 3D images produced from 150 meter grid DEM.

  14. Geometry Of The San Andreas Fault In The Salton Trough And Its Effect On Simulated Shaking For A Rupture Similar To That Of The Great California Shakeout Of 2008

    NASA Astrophysics Data System (ADS)

    Fuis, G. S.; Bauer, K.; Graves, R. W.; Aagaard, B.; Catchings, R.; Goldman, M.; Hole, J. A.; Langenheim, V. E.; Ryberg, T.; Rymer, M. J.; Scheirer, D. S.; Stock, J. M.

    2013-12-01

    The southernmost San Andreas fault (SAF) zone, in the northern Salton Trough, is considered likely to produce a large-magnitude, damaging earthquake in the near future (Jones et al., 2008, USGS OFR). The geometry of the SAF and adjacent sedimentary basins will strongly influence energy radiation and strong ground motion during a future rupture. The Salton Seismic Imaging Project (SSIP) was undertaken, in part, to provide more accurate information on SAF and basin geometry in this region. We report interpretations of seismic profiles in the Salton Trough (Lines 4-7). Lines 4 through 6 are SW-NE fault-perpendicular profiles that cross the Coachella Valley and extend into the mountain ranges on either side. Line 7 crosses the Salton Sea and sedimentary basin deposits similar to those of the Coachella Valley to the north. On three lines (4, 6, 7), seismic imaging, potential-field studies, and (or) earthquake hypocentral relocations provide evidence that active strands of the SAF dip moderately NE. Importantly, on Line 4, we have obtained a reflection image of the SAF zone, in the depth range of 5-10 km, that coincides with the microearthquake pattern here (Hauksson et al., 2012, BSSA). We interpret a moderate northeast dip (~60 deg.) for the SAF, as previously reported by Fuis et al. (2012, BSSA). We used a 3D finite-difference wave propagation method to model shaking in southern California expected from rupture on the SAF with the propeller-shaped geometry reported by Fuis et al. (2012), and we have compared this shaking to that modeled from the generally vertical geometry used in the Great California ShakeOut (Jones et al., 2008). Our results were obtained by projecting the kinematic 2008 ShakeOut rupture onto the newly characterized, dipping SAF geometry. We estimate higher levels of shaking on the hanging wall of the SAF (to the NE) and lower levels on the footwall (to the SW), as compared to the 2008 estimates. The change in ground motion level for most shaking quantities (PGA, PGV, 0.3 to 3 sec SA [spectral acceleration]) averages about +/- 20%. Southeast of Cajon Pass, where the change in fault dip between the propeller and 2008 ShakeOut geometries ranges from 10 to 50 deg., new modeled ground motions are systematically increased on the NE side by as much as a factor of 2 and decreased on the SW side by a similar amount compared to the shaking estimated in the 2008 ShakeOut rupture scenario. For the region northwest of Cajon Pass, this pattern is reversed despite the fact that the fault geometry is basically the same for the two models (vertical dip). We interpret this pattern to result from radiation pattern and directivity effects being carried northward from the southern portions of the fault.

  15. Fault geometry and cumulative offsets in the central Coast Ranges, California: Evidence for northward increasing slip along the San Gregorio-San Simeon-Hosgri fault

    USGS Publications Warehouse

    Langenheim, V.E.; Jachens, R.C.; Graymer, R.W.; Colgan, J.P.; Wentworth, C.M.; Stanley, R.G.

    2012-01-01

    Estimates of the dip, depth extent, and amount of cumulative displacement along the major faults in the central California Coast Ranges are controversial. We use detailed aeromagnetic data to estimate these parameters for the San Gregorio–San Simeon–Hosgri and other faults. The recently acquired aeromagnetic data provide an areally consistent data set that crosses the onshore-offshore transition without disruption, which is particularly important for the mostly offshore San Gregorio–San Simeon–Hosgri fault. Our modeling, constrained by exposed geology and in some cases, drill-hole and seismic-reflection data, indicates that the San Gregorio–San Simeon–Hosgri and Reliz-Rinconada faults dip steeply throughout the seismogenic crust. Deviations from steep dips may result from local fault interactions, transfer of slip between faults, or overprinting by transpression since the late Miocene. Given that such faults are consistent with predominantly strike-slip displacement, we correlate geophysical anomalies offset by these faults to estimate cumulative displacements. We find a northward increase in right-lateral displacement along the San Gregorio–San Simeon–Hosgri fault that is mimicked by Quaternary slip rates. Although overall slip rates have decreased over the lifetime of the fault, the pattern of slip has not changed. Northward increase in right-lateral displacement is balanced in part by slip added by faults, such as the Reliz-Rinconada, Oceanic–West Huasna, and (speculatively) Santa Ynez River faults to the east.

  16. The Evolution and Variability in Structural Style of Normal Fault Zones: Comparing Field Observations with Numerical Models

    NASA Astrophysics Data System (ADS)

    Gawthorpe, R. L.; Finch, E.; Jackson, C. A.

    2006-12-01

    Integration of high quality 3D seismic data from the North Sea, exceptional exposures of syn-rift stratigraphy and fault zones and 2D discrete element modelling provides information on the variability of structural style around segmented normal fault zones and the resultant changes due to fault growth and segment linkage. Using the geometry of syn-rift stratigraphy as an aid to reconstructing structural style, we focus on the 3D geometry of normal faults and associated structures during the rift initiation phase, prior to strain localisation on major tilt-block bounding fault zones. Early syn-rift stratigraphy indicates that surface deformation is initially characterised by a fault-parallel monocline above a blind fault tip that is often replaced, with increasing slip, by a through-going fault. Localisation onto a single fault produces fault-parallel hangingwall synclines and footwall anticlines as a result of breaching of the earlier monocline. This does not represent 'drag' against the fault. Secondary structures are common above the fault tip and comprise both synthetic and antithetic normal and reverse faults. Simultaneous faulting of competent materials and flow of weaker materials can lead to complex structural relationships. Faults in the cover can die out up and down section and do not necessarily link to the basement fault at depth. Similarly, complex ductile characteristics such as footwall thinning and hangingwall thickening can be juxtaposed against simple brittle fault cut-offs. Along-strike displacement gradients produce broad open folds and faults at high angles to the trace of the normal fault segment. These secondary structures show systematic decrease in amplitude and displacement into both hangingwall and footwall. 2D Discrete Element models are employed to examine the effect of heterogeneity in the cover on fold development and fault propagation. Experiments using a number of mechanically multi-layered cover sequences cause the distribution and timing of fractures and folds to vary dramatically.

  17. 3-D discrete analytical ridgelet transform.

    PubMed

    Helbert, David; Carré, Philippe; Andres, Eric

    2006-12-01

    In this paper, we propose an implementation of the 3-D Ridgelet transform: the 3-D discrete analytical Ridgelet transform (3-D DART). This transform uses the Fourier strategy for the computation of the associated 3-D discrete Radon transform. The innovative step is the definition of a discrete 3-D transform with the discrete analytical geometry theory by the construction of 3-D discrete analytical lines in the Fourier domain. We propose two types of 3-D discrete lines: 3-D discrete radial lines going through the origin defined from their orthogonal projections and 3-D planes covered with 2-D discrete line segments. These discrete analytical lines have a parameter called arithmetical thickness, allowing us to define a 3-D DART adapted to a specific application. Indeed, the 3-D DART representation is not orthogonal, It is associated with a flexible redundancy factor. The 3-D DART has a very simple forward/inverse algorithm that provides an exact reconstruction without any iterative method. In order to illustrate the potentiality of this new discrete transform, we apply the 3-D DART and its extension to the Local-DART (with smooth windowing) to the denoising of 3-D image and color video. These experimental results show that the simple thresholding of the 3-D DART coefficients is efficient. PMID:17153944

  18. "Intelligent design" of a 3D reflection survey for the SAFOD drill-hole site

    NASA Astrophysics Data System (ADS)

    Alvarez, G.; Hole, J. A.; Klemperer, S. L.; Biondi, B.; Imhof, M.

    2003-12-01

    SAFOD seeks to better understand the earthquake process by drilling though the San Andreas fault (SAF) to sample an earthquake in situ. To capitalize fully on the opportunities presented by the 1D drill-hole into a complex fault zone we must characterize the surrounding 3D geology at a scale commensurate with the drilling observations, to provide the structural context to extrapolate 1D drilling results along the fault plane and into the surrounding 3D volume. Excellent active-2D and passive-3D seismic observations completed and underway lack the detailed 3D resolution required. Only an industry-quality 3D reflection survey can provide c. 25 m subsurface sample-spacing horizontally and vertically. A 3D reflection survey will provide subsurface structural and stratigraphic control at the 100-m level, mapping major geologic units, structural boundaries, and subsurface relationships between the many faults that make up the SAF fault system. A principal objective should be a reflection-image (horizon-slice through the 3D volume) of the near-vertical fault plane(s) to show variations in physical properties around the drill-hole. Without a 3D reflection image of the fault zone, we risk interpreting drilled anomalies as ubiquitous properties of the fault, or risk missing important anomalies altogether. Such a survey cannot be properly costed or technically designed without major planning. "Intelligent survey design" can minimize source and receiver effort without compromising data-quality at the fault target. Such optimization can in principal reduce the cost of a 3D seismic survey by a factor of two or three, utilizing the known surface logistic constraints, partially-known sub-surface velocity field, and the suite of scientific targets at SAFOD. Our methodology poses the selection of the survey parameters as an optimization process that allows the parameters to vary spatially in response to changes in the subsurface. The acquisition geometry is locally optimized for uniformity of subsurface illumination by a micro-genetic algorithm. We start by accurately establishing the correspondence between the subsurface area of the target reflector (in this case, the steeply-dipping SAF) and the part of the surface area whose sources and receivers contribute to its image using 3D ray-tracing. We then use dense acquisition parameters in that part of the survey area and use standard parameters in the rest of the survey area. This is the key idea that allows us to get optimum image quality with the least acquisition effort. The optimization also requires constraints from structural geologists and from the community who will interpret the results. The most critical parameters to our optimization process are the structural model of the target(s) (depth and geological dips) and the velocity model in the subsurface. We seek community input, and have formed a scientific advisory committee of academic and industry leaders, to help evaluate trade-offs for the community between cost, resolution and volume of the resultant data-set, and to ensure that an appropriate range of piggy-back experiments is developed to utilize the seismic sources available during the 3D experiment. The scientific output of our project will be a community-vetted design for a 3D reflection survey over SAFOD that is technically feasible, cost-effective, and most likely to yield the image and seismic parameter measurements that will best constrain the physical properties of the fault zone and their spatial variation.

  19. San Andreas fault geometry at Desert Hot Springs, California, and its effects on earthquake hazards and groundwater

    USGS Publications Warehouse

    Catchings, R.D.; Rymer, M.J.; Goldman, M.R.; Gandhok, G.

    2009-01-01

    The Mission Creek and Banning faults are two of the principal strands of the San Andreas fault zone in the northern Coachella Valley of southern California. Structural characteristics of the faults affect both regional earthquake hazards and local groundwater resources. We use seismic, gravity, and geological data to characterize the San Andreas fault zone in the vicinity of Desert Hot Springs. Seismic images of the upper 500 m of the Mission Creek fault at Desert Hot Springs show multiple fault strands distributed over a 500 m wide zone, with concentrated faulting within a central 200 m wide area of the fault zone. High-velocity (up to 5000 m=sec) rocks on the northeast side of the fault are juxtaposed against a low-velocity (6.0) earthquakes in the area (in 1948 and 1986) occurred at or near the depths (~10 to 12 km) of the merged (San Andreas) fault. Large-magnitude earthquakes that nucleate at or below the merged fault will likely generate strong shaking from guided waves along both fault zones and from amplified seismic waves in the low-velocity basin between the two fault zones. The Mission Creek fault zone is a groundwater barrier with the top of the water table varying by 60 m in depth and the aquifer varying by about 50 m in thickness across a 200 m wide zone of concentrated faulting.

  20. Unassisted 3D camera calibration

    NASA Astrophysics Data System (ADS)

    Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.

    2012-03-01

    With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.

  1. Crustal Structure and Moho Geometry around the Alto Tiberina Fault (Northern Apennines) from Receiver Functions

    NASA Astrophysics Data System (ADS)

    Licciardi, A.; Chiaraluce, L.; Piana Agostinetti, N.; Amato, A.

    2013-12-01

    The Alto Tiberina Fault (ATF) is an unique example of active low angle normal fault (dip ? 15°), detected in the Northern Apennines from the interpretation of passive and active seismic data. This NW-SE striking structure has been mapped for a about 50 km along dip and is thought to have accumulated a total of 2 km of displacement in the last 2 Ma. In the last years, a dense, high resolution seismic network has been deployed in the area surrounding the ATF, with the aim of better understanding the physical mechanisms of earthquakes nucleation of such geological feature and assessing the potentially associated seismic hazard. In this context, a good knowledge of the elastic properties of rocks at depth is the starting points for building accurate and consistent physical models of ATF's style of deformation. We carried out a teleseismic receiver functions (RF) study on the 42 broadband seismic stations, using about 800 events from teleseismic distances, recorded from January 2010 to December 2011. We selected an average of about 70 high S/N ratio RFs per station, achieving a good azimuthal coverage for most of the stations. We separated the isotropic and the anisotropic component of the RF data-set through the harmonic decomposition. For each station, we performed a Monte Carlo inversion (using a reversible jump Markov chain Monte Carlo algorithm) of the isotropic component of the RF data-set, obtaining 1-D Vs profiles from the surface to 60km depth. This kind of inversion does not suffer of the problems related to the choice of a particular starting model, and has the advantage of inferring the degree of complexity (i.e. the number of layers) of the resulting model, directly from the data themselves. Preliminary results show an increasing level of structural complexity moving from west to east across the target area. A clear and shallow (~25 km) Moho is observed from the velocity profiles in the westernmost part of the region. Along the easternmost part, crustal velocity structures in correspondence of the highest peaks of the mountain chain reflects the continental subduction of the Adriatic lower crust under the Northern Apennines. In the central part of the target area, the presence of multiple interfaces and a very-low Vs in the subcrustal mantle make the crust-mantle transition more difficult to recognize. The final results will help in constraining crustal structures and rocks properties in the ATF area, providing a new piece of information in the more general comprehension of the physical processes acting in this unique natural laboratory.

  2. Integrated analysis of seismological, gravimetric and structural data for identification of active faults geometries in Abruzzo and Molise areas (Italy)

    NASA Astrophysics Data System (ADS)

    Gaudiosi, Germana; Nappi, Rosa; Alessio, Giuliana; Porfido, Sabina; Cella, Federico; Fedi, Maurizio; Florio, Giovanni

    2015-04-01

    This paper deals with an interdisciplinary research that has been carried out for more constraining the active faults and their geometry of Abruzzo - Molise areas (Central-Southern Apennines), two of the most active areas from a geodynamic point of view of the Italian Apennines, characterized by the occurrence of intense and widely spread seismic activity. An integrated analysis of structural, seismic and gravimetric (Gaudiosi et al., 2012) data of the area has been carried out through the Geographic Information System (GIS) which has provided the capability for storing and managing large amount of spatial data from different sources. In particular, the analysis has consisted of these main steps: (a) collection and acquisition of aerial photos, numeric cartography, Digital Terrain Model (DTM) data, geophysical data; (b) generation of the vector cartographic database and alpha-numerical data; c) image processing and features classification; d) cartographic restitution and multi-layers representation. In detail three thematic data sets have been generated "fault", "earthquake" and "gravimetric" data sets. The fault Dataset has been compiled by examining and merging the available structural maps, and many recent geological and geophysical papers of literature. The earthquake Dataset has been implemented collecting seismic data by the available historical and instrumental Catalogues and new precise earthquake locations for better constraining existence and activity of some outcropping and buried tectonic structures. Seismic data have been standardized in the same format into the GIS and merged in a final catalogue. For the gravimetric Dataset, the Multiscale Derivative Analysis (MDA) of the gravity field of the area has been performed, relying on the good resolution properties of the Enhanced Horizontal Derivative (EHD) (Fedi et al., 2005). MDA of gravity data has allowed localization of several trends identifying anomaly sources whose presence was not previously detected. The main results of our integrated analysis show a strong correlation among faults, hypocentral location of earthquakes and MDA lineaments from gravity data. Furthermore 2D seismic hypocentral locations together with high-resolution analysis of gravity anomalies have been correlated to estimate the fault systems parameters (strike, dip direction and dip angle) of some structures of the areas, through the application of the DEXP method (Fedi M. and M. Pilkington, 2012). References Fedi M., Cella F., Florio G., Rapolla A.; 2005: Multiscale Derivative Analysis of the gravity and magnetic fields of the Southern Apennines (Italy). In: Finetti I.R. (ed), CROP PROJECT: Deep Seismic Exploration of the Central Mediterranean and Italy, pp. 281-318. Fedi M., Pilkington M.; 2012: Understanding imaging methods for potential field data. Geophysics, 77: G13-G24. Gaudiosi G., Alessio G., Cella F., Fedi M., Florio G., Nappi, R.; 2012: Multiparametric data analysis for seismic sources identification in the Campanian area: merging of seismological, structural and gravimetric data. BGTA,. Vol. 53, n. 3, pp. 283-298.

  3. 3D geological modeling of the Trujillo block: Insights for crustal escape models of the Venezuelan Andes

    NASA Astrophysics Data System (ADS)

    Dhont, Damien; Monod, Bernard; Hervouët, Yves; Backé, Guillaume; Klarica, Stéphanie; Choy, José E.

    2012-11-01

    The Venezuelan Andes form a N50°E-trending mountain belt extending from the Colombian border in the SW to the Caribbean Sea in the NE. The belt began to rise since the Middle Miocene in response to the E-W collision between the Maracaibo block to the NW and the Guyana shield belonging to South America to the SE. This oblique collision led to strain partitioning with (1) shortening along opposite-vergent thrust fronts, (2) right-lateral slip along the Boconó fault crossing the belt more or less along-strike and (3) crustal escape of the Trujillo block moving towards the NE in between the Boconó fault and the N-S-striking left-lateral Valera fault. The geology of the Venezuelan Andes is well described at the surface, but its structure at depth remains hypothetic. We investigated the deep geometry of the Mérida Andes by a 3D model newly developed from geological and geophysical data. The 3D fault model is restricted to the crust and is mainly based on the surface data of outcropping fault traces. The final model reveals the orogenic float concept where the mountain belt is decoupled from its underlying lithosphere over a horizontal décollement located either at the upper/lower crust boundary. The reconstruction of the Boconó and Valera faults results in a 3D shape of the Trujillo block, which floats over a mid-crustal décollement horizon emerging at the Boconó-Valera triple junction. Motion of the Trujillo block is accompanied by a widespread extension towards the NE accommodated by normal faults with listric geometries such as for the Motatan, Momboy and Tuñame faults. Extension is explained by the gravitational spreading of the upper crust during the escape process.

  4. Enigmatic structures within salt walls of the Santos Basin-Part 1: Geometry and kinematics from 3D seismic reflection and well data

    NASA Astrophysics Data System (ADS)

    Jackson, Christopher A.-L.; Jackson, Martin P. A.; Hudec, Michael R.; Rodriguez, Clara R.

    2015-06-01

    Understanding intrasalt structure may elucidate the fundamental kinematics and, ultimately, the mechanics of diapir growth. However, there have been relatively few studies of the internal structure of salt diapirs outside the mining industry because their cores are only partly exposed in the field and poorly imaged on seismic reflection data. This study uses 3D seismic reflection and borehole data from the São Paulo Plateau, Santos Basin, offshore Brazil to document the variability in intrasalt structural style in natural salt diapirs. We document a range of intrasalt structures that record: (i) initial diapir rise; (ii) rise of lower mobile halite through an arched and thinned roof of denser, layered evaporites, and emplacement of an intrasalt sheet or canopy; (iii) formation of synclinal flaps kinematically linked to emplacement of the intrasalt allochthonous bodies; and (iv) diapir squeezing. Most salt walls contain simple internal anticlines. Only a few salt walls contain allochthonous bodies and breakout-related flaps. The latter occur in an area having a density inversion within the autochthonous salt layer, such that upper, anhydrite-rich, layered evaporites are denser than lower, more halite-rich evaporites. We thus interpret that most diapirs rose through simple fold amplification of internal salt stratigraphy but that locally, where a density inversion existed in the autochthonous salt, Rayleigh-Taylor overturn within the growing diapir resulted in the ascent of less dense evaporites into the diapir crest by breaching of the internal anticline. This resulted in the formation of steep salt-ascension zones or feeders and the emplacement of high-level intrasalt allocthonous sheets underlain by breakout-related flaps. Although regional shortening undoubtedly occurred on the São Paulo Plateau during the Late Cretaceous, we suggest this was only partly responsible for the complex intrasalt deformation. We suggest that, although based on the Santos Basin, our kinematic model may be more generally applicable to other salt-bearing sedimentary basins.

  5. Direct measurements of dust attenuation in z ? 1.5 star-forming galaxies from 3D-HST: Implications for dust geometry and star formation rates

    SciTech Connect

    Price, Sedona H.; Kriek, Mariska; Brammer, Gabriel B.; Conroy, Charlie; Schreiber, Natascha M. Förster; Wuyts, Stijn; Franx, Marijn; Fumagalli, Mattia; Lundgren, Britt; Momcheva, Ivelina; Nelson, Erica J.; Van Dokkum, Pieter G.; Skelton, Rosalind E.; Whitaker, Katherine E.

    2014-06-10

    The nature of dust in distant galaxies is not well understood, and until recently few direct dust measurements have been possible. We investigate dust in distant star-forming galaxies using near-infrared grism spectra of the 3D-HST survey combined with archival multi-wavelength photometry. These data allow us to make a direct comparison between dust around star-forming regions (A {sub V,} {sub H} {sub II}) and the integrated dust content (A {sub V,} {sub star}). We select a sample of 163 galaxies between 1.36 ? z ? 1.5 with H? signal-to-noise ratio ?5 and measure Balmer decrements from stacked spectra to calculate A {sub V,} {sub H} {sub II}. First, we stack spectra in bins of A {sub V,} {sub star}, and find that A {sub V,} {sub H} {sub II} = 1.86 A {sub V,} {sub star}, with a significance of ? = 1.7. Our result is consistent with the two-component dust model, in which galaxies contain both diffuse and stellar birth cloud dust. Next, we stack spectra in bins of specific star formation rate (log SSFR), star formation rate (log SFR), and stellar mass (log M {sub *}). We find that on average A {sub V,} {sub H} {sub II} increases with SFR and mass, but decreases with increasing SSFR. Interestingly, the data hint that the amount of extra attenuation decreases with increasing SSFR. This trend is expected from the two-component model, as the extra attenuation will increase once older stars outside the star-forming regions become more dominant in the galaxy spectrum. Finally, using Balmer decrements we derive dust-corrected H? SFRs, and find that stellar population modeling produces incorrect SFRs if rapidly declining star formation histories are included in the explored parameter space.

  6. SU-E-T-342: Use of Patient Geometry Measurements to Predict Dosimetric Gain with VMAT Over 3D for Chestwall and Regional Nodal Radiation

    SciTech Connect

    Dumane, V; Knoll, M; Green, S; Bakst, R; Hunt, M; Steinberger, E

    2014-06-01

    Purpose: To predict the dosimetric gain of VMAT over 3D for the treatment ofchestwall/IMN/supraclavicular nodes using geometric parameters acquired during simulation Methods: CT scans for 20 left and 20 right sided patients were retrospectively analyzed toobtain percent ipsilateral lung volume included in the PWT and supraclavicular fields, central lung depth (CLD), maximum lung depth (MLD), separation, chestwall concavity (defined here as the product of CLD and separation) and the maximum heart depth (MHD). VMAT, PWT and P/E plans were done for each case. The ipsilateral lung V20 Gy and mean, total lung V20 Gy and mean, heart V25 Gy and mean were noted for each plan. Correlation coefficients were obtained and linear regression models were built using data from the above training set of patients and then tested on 4 new patients. Results: The decrease in ipsilateral lung V20 Gy, total lung V20 Gy, ipsilateral lung mean and total lung mean with VMAT over PWT significantly (p<0.05) correlated with the percent volume of ipsilateral lung included in the PWT and supraclavicular fields with correlation coefficient values of r = 0.83, r = 0.77, r = 0.78 and r = 0.75 respectively. Significant correlations were also found between MHD and the decrease in heart V25 Gy and mean of r = 0.77 and r = 0.67 respectively. Dosimetric improvement with VMAT over P/E plans showed no correlation to any of the geometric parameters investigated in this study. The dosimetric gain predicted for the 4 test cases by the linear regression models given their respective percent ipsilateral lung volumes fell within the 95% confidence intervals around the best regression fit. Conclusion: The percent ipsilateral lung volume appears to be a strong predictor of the dosimetric gain on using VMAT over PWT apriori.

  7. Direct Measurement of Dust Attenuation in z approx. 1.5 Star-Forming Galaxies from 3D-HST: Implications for Dust Geometry and Star Formation Rates

    NASA Technical Reports Server (NTRS)

    Price, Sedona H.; Kriek, Mariska; Brammer, Gabriel B; Conroy, Charlie; Schreiber, Natascha M. Foerster; Franx, Marijn; Fumagalli, Mattia; Lundren, Britt; Momcheva, Ivelina; Nelson, Erica J.; Rix, Hans-Walter; Skelton, Rosalind E.; VanDokkum, Pieter G.; Tease, Katherine Whitaker; Wuyts, Stijn

    2013-01-01

    The nature of dust in distant galaxies is not well understood, and until recently few direct dust measurements have been possible. We investigate dust in distant star-forming galaxies using near-infrared grism spectra of the 3D-HST survey combined with archival multi-wavelength photometry. These data allow us to make a direct comparison between dust towards star-forming regions (measured using Balmer decrements) and the integrated dust properties (derived by comparing spectral energy distributions [SEDs] with stellar population and dust models) for a statistically significant sample of distant galaxies. We select a sample of 163 galaxies between 1.36< or = z< or = 1.5 with H(alpha) SNR > or = 5 and measure Balmer decrements from stacked spectra. First, we stack spectra in bins of integrated stellar dust attenuation, and find that there is extra dust extinction towards star-forming regions (AV,HII is 1.81 times the integrated AV, star), though slightly lower than found for low-redshift starburst galaxies. Next, we stack spectra in bins of specific star formation rate (log sSFR), star formation rate (log SFR), and stellar mass (logM*). We find that on average AV,HII increases with SFR and mass, but decreases with increasing sSFR. The amount of extra extinction also decreases with increasing sSFR and decreasing stellar mass. Our results are consistent with the two-phase dust model - in which galaxies contain both a diffuse and a stellar birth cloud dust component - as the extra extinction will increase once older stars outside the star-forming regions become more dominant. Finally, using our Balmer decrements we derive dust-corrected H(alpha) SFRs, and find evidence that SED fitting produces incorrect SFRs if very rapidly declining SFHs are included in the explored parameter space. Subject headings: dust, extinction- galaxies: evolution- galaxies: high-redshift

  8. Geometry, slip distribution, and kinematics of surface rupture on the Sakarya fault segment during the 17 August 1999 ?zmit, Turkey, earthquake

    USGS Publications Warehouse

    Langridge, R.M.; Stenner, H.D.; Fumal, T.E.; Christofferson, S.A.; Rockwell, T.K.; Hartleb, R.D.; Bachhuber, J.; Barka, A.A.

    2002-01-01

    The Mw 7.4 17 August 1999 ?zmit earthquake ruptured five major fault segments of the dextral North Anatolian Fault Zone. The 26-km-long, N86°W-trending Sakarya fault segment (SFS) extends from the Sapanca releasing step-over in the west to near the town of Akyazi in the east. The SFS emerges from Lake Sapanca as two distinct fault traces that rejoin to traverse the Adapazari Plain to Akyazi. Offsets were measured across 88 cultural and natural features that cross the fault, such as roads, cornfield rows, rows of trees, walls, rails, field margins, ditches, vehicle ruts, a dike, and ground cracks. The maximum displacement observed for the ?zmit earthquake (?5.1 m) was encountered on this segment. Dextral displacement for the SFS rises from less than 1 m at Lake Sapanca to greater than 5 m near Arifiye, only 3 km away. Average slip decreases uniformly to the east from Arifiye until the fault steps left from Sagir to Kazanci to the N75°W, 6-km-long Akyazi strand, where slip drops to less than 1 m. The Akyazi strand passes eastward into the Akyazi Bend, which consists of a high-angle bend (18°-29°) between the Sakarya and Karadere fault segments, a 6-km gap in surface rupture, and high aftershock energy release. Complex structural geometries exist between the ?zmit, Düzce, and 1967 Mudurnu fault segments that have arrested surface ruptures on timescales ranging from 30 sec to 88 days to 32 yr. The largest of these step-overs may have acted as a rupture segmentation boundary in previous earthquake cycles.

  9. The Makerbot: Desktop 3D printing

    E-print Network

    Roughan, Matthew

    Approximation of curves into straight lines Like much modern tech, the math is hidden #12;CSG http://en.wikipedia.org/wiki is Lots of maths hidden in something like 3D printing Geometry and Linear algebra ++ Same math used

  10. Co-seismic fault geometry and slip distribution of the 26 December 2004, giant Sumatra-Andaman earthquake constrained by GPS, coral reef, and remote sensing data

    NASA Astrophysics Data System (ADS)

    Wan, Yongge; Shen, Zheng-kang; Wang, Min; Zeng, Yuehua; Huang, Jichao; Li, Xiang; Cui, Huawei; Gao, Xiwei

    2015-06-01

    We analyze co-seismic displacement field of the 26 December 2004, giant Sumatra-Andaman earthquake derived from Global Position System observations, geological vertical measurement of coral head, and pivot line observed through remote sensing. Using the co-seismic displacement field and AK135 spherical layered Earth model, we invert co-seismic slip distribution along the seismic fault. We also search the best fault geometry model to fit the observed data. Assuming that the dip angle linearly increases in downward direction, the postfit residual variation of the inversed geometry model with dip angles linearly changing along fault strike are plotted. The geometry model with local minimum misfits is the one with dip angle linearly increasing along strike from 4.3o in top southernmost patch to 4.5o in top northernmost path and dip angle linearly increased. By using the fault shape and geodetic co-seismic data, we estimate the slip distribution on the curved fault. Our result shows that the earthquake ruptured ~200-km width down to a depth of about 60 km. 0.5-12.5 m of thrust slip is resolved with the largest slip centered around the central section of the rupture zone 7ºN-10ºN in latitude. The estimated seismic moment is 8.2 × 1022 N m, which is larger than estimation from the centroid moment magnitude (4.0 × 1022 N m), and smaller than estimation from normal-mode oscillation data modeling (1.0 × 1023 N m).

  11. A 3-D Geodynamic Model of Strain Partitioning in Southern California

    NASA Astrophysics Data System (ADS)

    Ye, J.; Liu, M.; Lin, F.

    2012-12-01

    In southern California, strain resulting from the relative motion between the Pacific and the North American plates is partitioned in a complex system of transcurrent, transcompressional, and transtensional faults. High-precision GPS measurements in this region have enabled kinematic modeling of the present-day strain partitioning between major faults in southern California. However, geodynamic models are needed to understand the cause of strain partitioning and to determine strain in regions where faults are blind or diffuse. We have developed a regional-scale geodynamic model of strain partitioning in southern California. This 3-D viscoelasto-plastic finite element model incorporates first-order fault geometry of the major active faults in the region. The model domain includes an elastoplastic upper crust on top of a viscoelastic lower lithospheric layer. Deformation is driven by the relative motion between the Pacific and the North American plates, imposed as a displacement boundary condition. Plastic deformation both within the fault zones and in the unfaulted surrounding crust is calculated. Our results show that the Big Bend of the San Andreas Fault, and other geometric complexity of faults in southern California, plays a major role in strain partitioning. The observed variations of strain portioning in southern California can be explained by the geometric configuration of fault systems relative to the relative plate motion, without appealing to basal traction of a flowing lower lithosphere. The model predicts concentrated plastic strain under the reverse fault systems in the Transverse Ranges and the young and diffuse faults in the Eastern California Shear Zone across the Mojave Desert, where a number damaging earthquakes occurred in the past decades.

  12. Acquisition and Visualization of Colored 3D Objects Stanford University

    E-print Network

    Washington at Seattle, University of

    Acquisition and Visualization of Colored 3D Objects Kari Pulli Stanford University Stanford, CA, U presents a complete system for scanning the geometry and surface color of a 3D object and for display- ing the system, emphasizing view-dependent texturing of geometric models. 2. 3D object reconstruction 3D object

  13. Acquisition and Visualization of Colored 3D Objects Stanford University

    E-print Network

    Shapiro, Linda

    Acquisition and Visualization of Colored 3D Objects Kari Pulli Stanford University Stanford, CA, U This paper presents a complete system for scanning the geometry and surface color of a 3D object. 2. 3D object reconstruction 3D object reconstruction consists of three steps: data ac- quisition

  14. 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.

  15. 3-D seismology in the Arabian Gulf

    SciTech Connect

    Al-Husseini, M.; Chimblo, R.

    1995-08-01

    Since 1977 when Aramco and GSI (Geophysical Services International) pioneered the first 3-D seismic survey in the Arabian Gulf, under the guidance of Aramco`s Chief Geophysicist John Hoke, 3-D seismology has been effectively used to map many complex subsurface geological phenomena. By the mid-1990s extensive 3-D surveys were acquired in Abu Dhabi, Oman, Qatar and Saudi Arabia. Also in the mid-1990`s Bahrain, Kuwait and Dubai were preparing to record surveys over their fields. On the structural side 3-D has refined seismic maps, focused faults and fractures systems, as well as outlined the distribution of facies, porosity and fluid saturation. In field development, 3D has not only reduced drilling costs significantly, but has also improved the understanding of fluid behavior in the reservoir. In Oman, Petroleum Development Oman (PDO) has now acquired the first Gulf 4-D seismic survey (time-lapse 3D survey) over the Yibal Field. The 4-D survey will allow PDO to directly monitor water encroachment in the highly-faulted Cretaceous Shu`aiba reservoir. In exploration, 3-D seismology has resolved complex prospects with structural and stratigraphic complications and reduced the risk in the selection of drilling locations. The many case studies from Saudi Arabia, Oman, Qatar and the United Arab Emirates, which are reviewed in this paper, attest to the effectiveness of 3D seismology in exploration and producing, in clastics and carbonates reservoirs, and in the Mesozoic and Paleozoic.

  16. Europeana and 3D

    NASA Astrophysics Data System (ADS)

    Pletinckx, D.

    2011-09-01

    The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.

  17. Optical diffraction from opal-based photonic structures: transition from 2D to 3D regimes

    NASA Astrophysics Data System (ADS)

    Sinev, Ivan S.; Rybin, Mikhail V.; Samusev, Anton K.; Samusev, Kirill B.; Trofimova, Ekaterina Y.; Kurdukov, Dmitry A.; Golubev, Valery G.; Limonov, Mikhail F.

    2012-06-01

    We report on experimental and theoretical investigations of light diffraction from opal films of different thickness. A special attention was paid to the transformation of diffraction patterns upon building up the opal structure from two-dimensional (2D) film structure towards bulk three-dimensional (3D) structure. In our setup the diffraction patterns are displayed on a narrow cylindrical screen with a specimen fixed in its center. The diffraction patterns have been studied visually and recorded in different scattering geometries with the films illuminated with white unpolarized light. With increasing number of layers, certain regions of 2D diffraction patterns fade out and finally form diffraction spots characteristic for 3D diffraction. We also found that stacking faults in bulk opals lead to formation of a 2D-like diffraction pattern, i.e. such structure demonstrate 3D to quasi-2D transition in optical properties.

  18. A 3-D Model of Stacked Thrusts in the Sevier Thrust Belt, Eastern Idaho

    NASA Astrophysics Data System (ADS)

    Clayton, R. W.; Clayton, S. R.

    2014-12-01

    Using published and new geologic map data and two exploratory wells for control, we constructed a three-dimensional geological model of the Pine Creek area in the Big Hole Mountains of eastern Idaho, where stacked Sevier thrust sheets are exposed at the surface. In this area, Cretaceous crustal shortening displaced and folded strata from Cambrian to Cretaceous in age. Using geologic map data as a primary input to a 3-D model presents a number of challenges, especially representing fault geometries at depth and maintaining strata thicknesses. The highly variable attitudes measured at the surface are also difficult to represent in a subsurface model because they require extensive extrapolation to depth. To overcome these challenges we EarthVision software, which has tools for model construction with minimal data inputs and uses a minimum tension algorithm to create geologically realistic surfaces. We also constructed two primary cross-sections to constrain strata and fault geometries according to structural principles, and used these to guide construction of fault and horizon surfaces. We then designated horizons with the best control as reference horizons to constrain strata geometries, and built the remaining horizons using isochores to add or subtract from those surfaces. The model shows classic flat-ramp thrust geometries as seen farther southeast in the Wyoming section of the thrust belt. The model also shows uniform southwestward tilting of faults and strata in the north end above younger thrusts, but strong effects from a duplex on a younger thrust fault encountered in the southern well, which rotated the strata and older faults above it.

  19. Constraining the slip distribution and fault geometry of the Mw 7.9, 3 November 2002, Denali fault earthquake with Interferometric Synthetic Aperture Radar and Global Positioning System data

    USGS Publications Warehouse

    Wright, Tim J.; Lu, Zhiming; Wicks, C.

    2004-01-01

    The Mw 7.9, Denali fault earthquake (DFE) is the largest continental strike-slip earthquake to occur since the development of Interferometric Synthetic Aperture Radar (InSAR). We use five interferograms, constructed using radar images from the Canadian Radarsat-1 satellite, to map the surface deformation at the western end of the fault rupture. Additional geodetic data are provided by displacements observed at 40 campaign and continuous Global Positioning System (GPS) sites. We use the data to determine the geometry of the Susitna Glacier fault, thrusting on which initiated the DFE, and to determine a slip model for the entire event that is consistent with both the InSAR and GPS data. We find there was an average of 7.3 ± 0.4 m slip on the Susitna Glacier fault, between 1 and 9.5 km depth on a 29 km long fault that dips north at 41 ± 0.7° and has a surface projection close to the mapped rupture. On the Denali fault, a simple model with large slip patches finds a maximum of 8.7 ± 0.7 m of slip between the surface and 14.3 ± 0.2 km depth. A more complex distributed slip model finds a peak of 12.5 ± 0.8 m in the upper 4 km, significantly higher than the observed surface slip. We estimate a geodetic moment of 670 ± 10 × 1018 N m (Mw 7.9), consistent with seismic estimates. Lack of preseismic data resulted in an absence of InSAR coverage for the eastern half of the DFE rupture. A dedicated geodetic InSAR mission could obviate coverage problems in the future.

  20. Dynamic earthquake rupture modelled with an unstructured 3-D spectral element method applied to the 2011 M9 Tohoku earthquake

    NASA Astrophysics Data System (ADS)

    Galvez, P.; Ampuero, J.-P.; Dalguer, L. A.; Somala, S. N.; Nissen-Meyer, T.

    2014-08-01

    An important goal of computational seismology is to simulate dynamic earthquake rupture and strong ground motion in realistic models that include crustal heterogeneities and complex fault geometries. To accomplish this, we incorporate dynamic rupture modelling capabilities in a spectral element solver on unstructured meshes, the 3-D open source code SPECFEM3D, and employ state-of-the-art software for the generation of unstructured meshes of hexahedral elements. These tools provide high flexibility in representing fault systems with complex geometries, including faults with branches and non-planar faults. The domain size is extended with progressive mesh coarsening to maintain an accurate resolution of the static field. Our implementation of dynamic rupture does not affect the parallel scalability of the code. We verify our implementation by comparing our results to those of two finite element codes on benchmark problems including branched faults. Finally, we present a preliminary dynamic rupture model of the 2011 Mw 9.0 Tohoku earthquake including a non-planar plate interface with heterogeneous frictional properties and initial stresses. Our simulation reproduces qualitatively the depth-dependent frequency content of the source and the large slip close to the trench observed for this earthquake.

  1. TAURUS. 3-D Finite Element Code Postprocessor

    SciTech Connect

    Whirley, R.G.

    1993-11-30

    TAURUS reads the binary plot files generated by the LLNL three-dimensional finite element analysis codes, NIKE3D, DYNA3D, TACO3D, TOPAZ3D, and GEMINI and plots contours, time histories,and deformed shapes. Contours of a large number of quantities may be plotted on meshes consisting of plate, shell, and solid type elements. TAURUS can compute a variety of strain measures, reaction forces along constrained boundaries, and momentum. TAURUS has three phases: initialization, geometry display with contouring, and time history processing.

  2. TAURUS. 3-d Finite Element Code Postprocessor

    SciTech Connect

    Whirley, R.G.

    1992-03-03

    TAURUS reads the binary plot files generated by the LLNL three-dimensional finite element analysis codes, NIKE3D (ESTSC 139), DYNA3D (ESTSC 138), TACO3D (ESTSC 287), TOPAZ3D (ESTSC 231), and GEMINI (ESTSC 455) and plots contours, time histories,and deformed shapes. Contours of a large number of quantities may be plotted on meshes consisting of plate, shell, and solid type elements. TAURUS can compute a variety of strain measures, reaction forces along constrained boundaries, and momentum. TAURUS has three phases: initialization, geometry display with contouring, and time history processing.

  3. TAURUS. 3-d Finite Element Code Postprocessor

    SciTech Connect

    Whirley, R.G.

    1991-05-01

    TAURUS reads the binary plot files generated by the LLNL three-dimensional finite element analysis codes, NIKE3D (ESTSC 139), DYNA3D (ESTSC 138), TACO3D (ESTSC 287), TOPAZ3D (ESTSC 231), and GEMINI (ESTSC 455) and plots contours, time histories,and deformed shapes. Contours of a large number of quantities may be plotted on meshes consisting of plate, shell, and solid type elements. TAURUS can compute a variety of strain measures, reaction forces along constrained boundaries, and momentum. TAURUS has three phases: initialization, geometry display with contouring, and time history processing.

  4. TAURUS. 3-D Finite Element Code Postprocessor

    SciTech Connect

    Whirley, R.G.

    1984-05-01

    TAURUS reads the binary plot files generated by the LLNL three-dimensional finite element analysis codes, NIKE3D, DYNA3D, TACO3D, TOPAZ3D, and GEMINI and plots contours, time histories,and deformed shapes. Contours of a large number of quantities may be plotted on meshes consisting of plate, shell, and solid type elements. TAURUS can compute a variety of strain measures, reaction forces along constrained boundaries, and momentum. TAURUS has three phases: initialization, geometry display with contouring, and time history processing.

  5. TAURUS. 3-D Finite Element Code Postprocessor

    SciTech Connect

    Whirley, R.G.

    1992-03-03

    TAURUS reads the binary plot files generated by the LLNL three-dimensional finite element analysis codes, NIKE3D, DYNA3D, TACO3D, TOPAZ3D, and GEMINI and plots contours, time histories,and deformed shapes. Contours of a large number of quantities may be plotted on meshes consisting of plate, shell, and solid type elements. TAURUS can compute a variety of strain measures, reaction forces along constrained boundaries, and momentum. TAURUS has three phases: initialization, geometry display with contouring, and time history processing.

  6. TAURUS. 3-D Finite Element Code Postprocessor

    SciTech Connect

    Kennedy, T.

    1992-03-03

    TAURUS reads the binary plot files generated by the LLNL three-dimensional finite element analysis codes, NIKE3D, DYNA3D, TACO3D, TOPAZ3D, and GEMINI and plots contours, time histories, and deformed shapes. Contours of a large number of quantities may be plotted on meshes consisting of plate, shell, and solid type elements. TAURUS can compute a variety of strain measures, reaction forces along constrained boundaries, and momentum. TAURUS has three phases: initialization, geometry display with contouring, and time history processing.

  7. Normal Fault Basin Geometries From Gravity Analyses in the La Paz - Los Cabos Region, Baja California Sur, Mexico

    NASA Astrophysics Data System (ADS)

    Busch, M. M.; Coyan, J. A.; Arrowsmith, J. R.; Umhoefer, P. J.; Martinez-Gutierrez, G.

    2008-12-01

    The southern cape region of the Baja California peninsula is ruptured by an array of roughly north-striking, left-stepping active normal faults, which accommodate regional transtension. Dominant faults within this system include the Carrizal, San Juan de los Planes (SJP) (and offshore Espiritu Santo fault), La Gata, and San Jose del Cabo (SJC) faults. We conducted gravity surveys across the basins bounded by these faults to gain insight into fault slip rates and basin evolution to better understand the role of upper-crustal processes during development of an obliquely rifted plate margin. The geodetic location of each gravity observation station was measured to cm-scale accuracy with real-time kinematic GPS and the relative gravity was measured with a LaCoste and Romberg Model G gravity meter to an accuracy of 0.01 mgal. Gravity data were modeled as a 2D two-layer model with a bedrock density of 2.67 g/cm3 and a basin fill density of 2.1 or 2.2 g/cm3. The hanging wall of the east-dipping Carrizal fault hosts the La Paz basin. In the subsurface, this basin is a half-graben that is manifest as two smaller basins (few hundred meters deep) separated by a bedrock high, which likely reflects the two main east-dipping splays (Carrizal and Centenario faults). The SJP basin is a graben bound by the SJP fault on the west and the La Gata fault on the east and has a modeled maximum depth of approximately 1.5 km. This basin is marked by a series of relict normal faults dipping toward the basin center. The maximum depth to bedrock is just northwest of center, asymmetric toward the SJP fault, indicating that slip may be greater along the SJP than along the La Gata fault. It might also mark the possible location of basin inception, indicating that as the basin evolved, faulting moved outward to the presently active SJP and La Gata Faults. The SJC basin has a maximum depth of approximately 2.5 km. The favored gravity model depicts the SJC basin as resulting from slip along a series of normal faults predominantly dipping toward the basin center (east). Bedrock topography within the basin could be attributed to paleotopography; however, with up to 1 km of relief, the interpreted faults seem more likely. The SJC basin has the greatest depth to bedrock, signifying that it accommodates a greater slip rate than the other faults within this system or that it accommodates equal slip but was the first to initiate. The adjacent topography is also the highest, indicating that the modern deformation has been stationary spatially for some time in contrast to the SJP fault, which has low footwall topography. It is likely that the SJP basin is a graben that serves to transfer strain between the larger Carrizal and Espiritu Santo faults and the SJC fault. An offshore CHIRP survey completed in late August, 2008 will provide further insight into the extent and interactions of faults within this system.

  8. On the robustness and resolving power of stress inversions based on focal mechanisms or slickenside data in the presence of complex fault geometry

    NASA Astrophysics Data System (ADS)

    Plenkers, K.; Becker, T. W.

    2006-12-01

    We use synthetic seismicity catalogs to test the resolving power of stress inversion methods that are based on focal mechanisms or slickenside data. It is analyzed whether and under which conditions stress inversions are able to find the true, tectonic stress field. The latter is here assumed to be homogeneous for simplicity. Catalogs are generated using boundary element models of fault systems with randomly generated geometries of varying degree of complexity. Slip on faults is obtained by applying a stress tensor representing background loading and then resolving the stress on the fault planes. Rupture occurs following a simple static-dynamic, Coulomb failure criterion, while stress interactions among faults are taken into account. Two approaches are tested: The methods of Gephart and Forsyth (1984) and of Michael (1984, 1987). The inversion results for best- fit stress from the realized earthquake slips are compared with the true, applied stress tensor. Both methods find solutions that coincide with the true tensor, as well as solutions with large misfits. We show how differences in the fault model geometry and in the choice of seismicity "data" affect the misfit distribution. Two parameters can be identified which may affect the misfit significantly due to the inherent lack of information in the inversion process. First, the mean misfit may increase significantly for Gephart and Forsyth's method when going from inversions performed with input data from heterogeneously oriented fault systems to those with homogeneous orientations, as measured by the distribution of the fault strikes. This measure is related to the well known heterogeneity requirement of stress inversions. Second, results with misfits consistently smaller than 15° for major compressive stress axes are only found for inversions with an "effective input data number" higher than a critical number. This effective number can be defined such that it reflects the true amount of information in the input data, taking into account geometrical redundancies. Furthermore, we show that the formal misfit as determined by the inversions does not always coincide with the true misfit, as assumed in some other studies. This is because of ambiguities where solutions for wrong stress tensors fit as well as the true stress tensor in the case of poor data quality.

  9. Three-dimensional structural modeling of an active fault zone based on complex outcrop and subsurface data: The Middle Durance Fault Zone inherited from polyphase Meso-Cenozoic tectonics (southeastern France)

    NASA Astrophysics Data System (ADS)

    Guyonnet-Benaize, Cédric; Lamarche, Juliette; Hollender, Fabrice; Viseur, Sophie; Münch, Philippe; Borgomano, Jean

    2015-02-01

    The objective of this study was to realize a three-dimensional (3-D) geological model of the deep basin structure of the Middle Durance region (of folds and faults) by integration of geological and geophysical data, and to evaluate its fault geometry and tectonic history. All of the available geophysical and geological data were compiled in three dimensions using the gOcad geomodeler. The geological and geophysical data were used to build a 3-D geological model of the Middle Durance region. The data on the 3-D geometry of fault surfaces and stratigraphic horizons and the thickness maps of the main stratigraphic units are supported by the 3-D geological model. We show that the Middle Durance Fault cannot be interpreted as a single fault plane that affected the entire Meso-Cenozoic sedimentary layers and the Paleozoic basement but as a listric segmented faulting system in sedimentary layers, rooted in Triassic evaporites and a normal block faulting system in the basement. This decoupling level in the Triassic layers reveals thin-skin deformation, formed by strong mechanical decoupling between the Mesozoic sedimentary cover and the Paleozoic basement. This study also confirms that the Provence geological structure has resulted mainly from Pyrenean deformation, which was partly reactivated by Alpine deformation. We demonstrate that the Middle Durance Fault Zone is a transfer fault that accommodates deformation of the sedimentary filling of the South-East Basin through modified fold geometry over a zone of 7 km to 8 km around the main segment of the fault zone.

  10. Geometry of the Nojima fault at Nojima-Hirabayashi, Japan - I. A simple damage structure inferred from borehole core permeability

    USGS Publications Warehouse

    Lockner, D.A.; Tanaka, H.; Ito, H.; Ikeda, R.; Omura, K.; Naka, H.

    2009-01-01

    The 1995 Kobe (Hyogo-ken Nanbu) earthquake, M = 7.2, ruptured the Nojima fault in southwest Japan. We have studied core samples taken from two scientific drillholes that crossed the fault zone SW of the epicentral region on Awaji Island. The shallower hole, drilled by the Geological Survey of Japan (GSJ), was started 75 m to the SE of the surface trace of the Nojima fault and crossed the fault at a depth of 624 m. A deeper hole, drilled by the National Research Institute for Earth Science and Disaster Prevention (NIED) was started 302 m to the SE of the fault and crossed fault strands below a depth of 1140 m. We have measured strength and matrix permeability of core samples taken from these two drillholes. We find a strong correlation between permeability and proximity to the fault zone shear axes. The half-width of the high permeability zone (approximately 15 to 25 m) is in good agreement with the fault zone width inferred from trapped seismic wave analysis and other evidence. The fault zone core or shear axis contains clays with permeabilities of approximately 0.1 to 1 microdarcy at 50 MPa effective confining pressure (10 to 30 microdarcy at in situ pressures). Within a few meters of the fault zone core, the rock is highly fractured but has sustained little net shear. Matrix permeability of this zone is approximately 30 to 60 microdarcy at 50 MPa effective confining pressure (300 to 1000 microdarcy at in situ pressures). Outside this damage zone, matrix permeability drops below 0.01 microdarcy. The clay-rich core material has the lowest strength with a coefficient of friction of approximately 0.55. Shear strength increases with distance from the shear axis. These permeability and strength observations reveal a simple fault zone structure with a relatively weak fine-grained core surrounded by a damage zone of fractured rock. In this case, the damage zone will act as a high-permeability conduit for vertical and horizontal flow in the plane of the fault. The fine-grained core region, however, will impede fluid flow across the fault. ?? Birkh??user Verlag, Basel 2009.

  11. 3D whiteboard: collaborative sketching with 3D-tracked smart phones

    NASA Astrophysics Data System (ADS)

    Lue, James; Schulze, Jürgen P.

    2014-02-01

    We present the results of our investigation of the feasibility of a new approach for collaborative drawing in 3D, based on Android smart phones. Our approach utilizes a number of fiduciary markers, placed in the working area where they can be seen by the smart phones' cameras, in order to estimate the pose of each phone in the room. Our prototype allows two users to draw 3D objects with their smart phones by moving their phones around in 3D space. For example, 3D lines are drawn by recording the path of the phone as it is moved around in 3D space, drawing line segments on the screen along the way. Each user can see the virtual drawing space on their smart phones' displays, as if the display was a window into this space. Besides lines, our prototype application also supports 3D geometry creation, geometry transformation operations, and it shows the location of the other user's phone.

  12. Low-angle extensional faulting, reactivated mylonites, and seismic reflection geometry of the Newark basin margin in eastern Pennsylvania

    SciTech Connect

    Ratcliffe, N.M.; Burton, W.C.; D'Angelo, R.M.; Costain, J.K.

    1986-09-01

    Low-angle 25/sup 0/ to 35/sup 0/ dips have been determined for the border fault of the Newark basin near Riegelsville, Pennsylvania, on the basis of a Vibroseis profile and two continuously cored drill holes across faults at the basin margin. A group of moderately strong planar reflections in a zone 0.5 km thick in gneiss and carbonate rocks of the footwall block coincides with the updip projection of imbricate fault slices and mylonites associated with the Musconetcong thrust system of Drake et al. (1967). Contrasts in acoustic impedance among mylonitic dolostone and mylonitic gneiss and their protoliths, determined from measurements on samples from a third cored hole, are sufficiently large to account for reflections seen in the footwall block. Analysis of drill core and surface outcrops supports the conclusion that low-angle extensional faulting in the early Mesozoic was localized by reactivation of Paleozoic imbricate thrust faults in the basement rocks. Extension in the northwest-southeast quadrant was approximately perpendicular to the strike of the ancient thrust faults in eastern Pennsylvania. The data presented here are the most explicit three-dimensional information obtained thus far in the eastern US in support of the concept of fault reactivation in controlling formation of early Mesozoic extensional basins.

  13. Seismic reflection geometry of the Newark basin margin in Eastern Pennsylvania. Evidence for extensional reactivation of Paleozoic thrust faults

    SciTech Connect

    Ratcliffe, N.M.; Burton, W.C.; D'Angelo, R.M.; Costain, J.K.

    1986-07-01

    Low-angle 25/sup 0/ to 35/sup 0/ dips have been determined for the border fault of the Newark basin near Riegelsville, Pennsylvania, based on a VIBROSEIS profile and two continuously-cored drill holes across faults at the basin margin. A group of moderately strong planar reflections in a zone 0.5 km thick in gneiss and carbonate rocks of the footwall block coincide with the updip projection of imbricate fault slices and mylonites associated with the Musconetcong thrust system of Drake and others (1967). Contrasts in acoustic impedance among mylonitic dolostone and mylonitic gneiss and their protoliths, determined from measurements on core samples, are sufficiently large to account for reflections seen in the footwall block. Analysis of drill core and surface outcrops supports the conclusion that low-angle extensional faulting in the Early Mesozoic was localized by reactivation of Paleozoic imbricate thrust faults in the basement rocks. Extension in the NW-SE quadrant was approximately perpendicular to the strike of the ancient thrust faults in Eastern Pennsylvania and a passive origin of the Newark basin here is suggested. The data presented here represent some of the most explicit three-dimensional information obtained thus far, in the Eastern United States, in support of the concept of fault reactivation in controlling formation of Early Mesozoic extensional basins.

  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. 3D and Education

    NASA Astrophysics Data System (ADS)

    Meulien Ohlmann, Odile

    2013-02-01

    Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?

  16. Investigation Of North Anatolian Fault In The Sea Of Marmara: Fault Geometry, The Cumulative Extension, Age Modeling In Çinarcik Basin Using Multi Channel Seismic Reflection Data

    NASA Astrophysics Data System (ADS)

    Atg?n, Orhan; Çifçi, Günay; Soelien, Christopher; Seeber, Leonardo; Steckler, Michael; Shillington, Donna; Kurt, Hülya; Dondurur, Derman; Okay, Seda; Gürçay, Sava?; Sar?ta?, Hakan; Mert Küçük, H.; Bar?n, Burcu

    2013-04-01

    Marmara Sea is a limelight area for investigations due to its tectonic structure and remarkable seismic activity of North Anatolian Fault Zone (NAFZ). As NAFZ separates into 3 branches in the Marmara Sea, it has a complicated tectonic structure which gives rise to debates among researchers. Ç?narc?k Basin, which is close to Istanbul and very important for its tectonic activity is studied in this thesis. Two different multichannel seismic reflection data were used in this thesis. First data were acquired in 2008 in the frame of TAMAM (Turkish American Multichannel Project) and second data were in 2010 in the frame of TAMAM-2 (PirMarmara) onboard R/V K.Piri Reis. Also high resolution multibeam data were used which is provided by French Marine Institute IFREMER. In the scope of TAMAM project total 3000 km high resolution multi channel data were collected. 3000 km of multichannel seismic reflection profiles were collected in 2008 and 2010 using 72, 111, and 240 channels of streamer with a 6.25 m group interval. The generator-injector airgun was fired every 12.5 or 18.75 m and the resulting MCS data has 10-230 Hz frequency band. In this study, a detailed fault map of the basin is created and the fault on the southern slope of the basin which is interpreted by many researchers in many publications was investigated. And there is no evidence that such a fault exists on the southern part of the basin. With the multichannel seismic reflection data seismic stratigrafic interpretations of the basin deposits were done. The yearly cumulative north-south extension of the basin was calculated by making some calculations on the most active part of the faulting in the basin. In addition, the tilt angles of parallel tilted sediments were calculated and correlated with global sea level changes to calculate ages of the deposits in the basin. Keywords: NAFZ, multi channel seismic reflection, Ç?narc?k Basin

  17. The quaternion Bingham Distribution, 3D object detection, and dynamic manipulation

    E-print Network

    Glover, Jared Marshall

    2014-01-01

    Over the past few years, the field of robotic computer vision has undergone a 3-D revolution. One of the biggest challenges in dealing with 3-D geometry lies in appropriately handling 3-D rotational data. To specify "where" ...

  18. Gravity and magnetic expression of the San Leandro gabbro with implications for the geometry and evolution of the Hayward Fault zone, northern California

    USGS Publications Warehouse

    Ponce, D.A.; Hildenbrand, T.G.; Jachens, R.C.

    2003-01-01

    The Hayward Fault, one of the most hazardous faults in northern California, trends north-northwest and extends for about 90 km along the eastern San Francisco Bay region. At numerous locations along its length, distinct and elongate gravity and magnetic anomalies correlate with mapped mafic and ultramafic rocks. The most prominent of these anomalies reflects the 16-km-long San Leandro gabbroic block. Inversion of magnetic and gravity data constrained with physical property measurements is used to define the subsurface extent of the San Leandro gabbro body and to speculate on its origin and relationship to the Hayward Fault Zone. Modeling indicates that the San Leandro gabbro body is about 3 km wide, dips about 75??-80?? northeast, and extends to a depth of at least 6 km. One of the most striking results of the modeling, which was performed independently of seismicity data, is that accurately relocated seismicity is concentrated along the western edge or stratigraphically lower bounding surface of the San Leandro gabbro. The western boundary of the San Leandro gabbro block is the base of an incomplete ophiolite sequence and represented at one time, a low-angle roof thrust related to the tectonic wedging of the Franciscan Complex. After repeated episodes of extension and attenuation, the roof thrust of this tectonic wedge was rotated to near vertical, and in places, the strike-slip Hayward Fault probably reactivated or preferentially followed this pre-existing feature. Because earthquakes concentrate near the edge of the San Leandro gabbro but tend to avoid its interior, we qualitatively explore mechanical models to explain how this massive igneous block may influence the distribution of stress. The microseismicity cluster along the western flank of the San Leandro gabbro leads us to suggest that this stressed volume may be the site of future moderate to large earthquakes. Improved understanding of the three-dimensional geometry and physical properties along the Hayward Fault will provide additional constraints on seismic hazard probability, earthquake modeling, and fault interactions that are applicable to other major strike-slip faults around the world.

  19. Geometry of the Nojima fault at Nojima-Hirabayashi, Japan - II. Microstructures and their implications for permeability and strength

    USGS Publications Warehouse

    Moore, Diane E.; Lockner, D.A.; Ito, H.; Ikeda, R.; Tanaka, H.; Omura, K.

    2009-01-01

    Samples of damage-zone granodiorite and fault core from two drillholes into the active, strike-slip Nojima fault zone display microstructures and alteration features that explain their measured present-day strengths and permeabilities and provide insight on the evolution of these properties in the fault zone. The least deformed damage-zone rocks contain two sets of nearly perpendicular (60-90?? angles), roughly vertical fractures that are concentrated in quartz-rich areas, with one set typically dominating over the other. With increasing intensity of deformation, which corresponds generally to increasing proximity to the core, zones of heavily fragmented rock, termed microbreccia zones, develop between prominent fractures of both sets. Granodiorite adjoining intersecting microbreccia zones in the active fault strands has been repeatedly fractured and locally brecciated, accompanied by the generation of millimeter-scale voids that are partly filled with secondary minerals. Minor shear bands overprint some of the heavily deformed areas, and small-scale shear zones form from the pairing of closely spaced shear bands. Strength and permeability measurements were made on core collected from the fault within a year after a major (Kobe) earthquake. Measured strengths of the samples decrease regularly with increasing fracturing and fragmentation, such that the gouge of the fault core and completely brecciated samples from the damage zone are the weakest. Permeability increases with increasing disruption, generally reaching a peak in heavily fractured but still more or less cohesive rock at the scale of the laboratory samples. Complete loss of cohesion, as in the gouge or the interiors of large microbreccia zones, is accompanied by a reduction of permeability by 1-2 orders of magnitude below the peak values. The core samples show abundant evidence of hydrothermal alteration and mineral precipitation. Permeability is thus expected to decrease and strength to increase somewhat in active fault strands between earthquakes, as mineral deposits progressively seal fractures and fill pore spaces. ?? Birkh??user Verlag, Basel 2009.

  20. Chapter Animation 74 Essential Java 3D fast

    E-print Network

    Hill, Gary

    Chapter Animation #12;74 Essential Java 3D fast Introduction The applications that we've created so. This is possible in Java3D through the use of the Morph class, which takes multiple GeometryArrays and interpolates: the time for the constant low alpha value #12;76 Essential Java 3D fast This is shown diagrammatically

  1. Proactive 3D Scanning of Inaccessible Parts Feilong Yan

    E-print Network

    Sharf, Andrei

    . Holes and undersampled regions are common in 3D scans of complex-shaped objects with self occlusions and tedious steps. A major challenge in scanning 3D objects is to capture their com- plete geometry. Proper to scan accessibility as parts in the 3D object are hidden by physical occlusions and cannot be scanned

  2. 3D Scene Understanding by Voxel-CRF Byung-soo Kim

    E-print Network

    Kohli, Pushmeet

    3D Scene Understanding by Voxel-CRF Byung-soo Kim University of Michigan bsookim@umich.edu Pushmeet to help simplify the problem of inferring scene semantics. However, while the added 3D geometry in that the 3D geometry is often incorrect because of noisy depth mea- surements and the actual 3D extent

  3. 3D Imaging.

    ERIC Educational Resources Information Center

    Hastings, S. K.

    2002-01-01

    Discusses 3 D imaging as it relates to digital representations in virtual library collections. Highlights include X-ray computed tomography (X-ray CT); the National Science Foundation (NSF) Digital Library Initiatives; output peripherals; image retrieval systems, including metadata; and applications of 3 D imaging for libraries and museums. (LRW)

  4. iBem3D, a three-dimensional iterative boundary element method using angular dislocations for modeling geologic structures

    NASA Astrophysics Data System (ADS)

    Maerten, F.; Maerten, L.; Pollard, D. D.

    2014-11-01

    Most analytical solutions to engineering or geological problems are limited to simple geometries. For example, analytical solutions have been found to solve for stresses around a circular hole in a plate. To solve more complex problems, mathematicians and engineers have developed powerful computer-aided numerical methods, which can be categorized into two main types: differential methods and integral methods. The finite element method (FEM) is a differential method that was developed in the 1950s and is one of the most commonly used numerical methods today. Since its development, other differential methods, including the boundary element method (BEM), have been developed to solve different types of problems. The purpose of this paper is to describe iBem3D, formally called Poly3D, a C++ and modular 3D boundary element computer program based on the theory of angular dislocations for modeling three-dimensional (3D) discontinuities in an elastic, heterogeneous, isotropic whole- or half-space. After 20 years and more than 150 scientific publications, we present in detail the formulation behind this method, its enhancements over the years as well as some important applications in several domains of the geosciences. The main advantage of using this formulation, for describing geological objects such as faults, resides in the possibility of modeling complex geometries without gaps and overlaps between adjacent triangular dislocation elements, which is a significant shortcoming for models using rectangular dislocation elements. Reliability, speed, simplicity, and accuracy are enhanced in the latest version of the computer code. Industrial applications include subseismic fault modeling, fractured reservoir modeling, interpretation and validation of fault connectivity and reservoir compartmentalization, depleted area and fault reactivation, and pressurized wellbore stability. Academic applications include earthquake and volcano monitoring, hazard mitigation, and slope stability modeling.

  5. A grid-doubling finite-element technique for calculating dynamic three-dimensional spontaneous rupture on an earthquake fault

    USGS Publications Warehouse

    Barall, M.

    2009-01-01

    We present a new finite-element technique for calculating dynamic 3-D spontaneous rupture on an earthquake fault, which can reduce the required computational resources by a factor of six or more, without loss of accuracy. The grid-doubling technique employs small cells in a thin layer surrounding the fault. The remainder of the modelling volume is filled with larger cells, typically two or four times as large as the small cells. In the resulting non-conforming mesh, an interpolation method is used to join the thin layer of smaller cells to the volume of larger cells. Grid-doubling is effective because spontaneous rupture calculations typically require higher spatial resolution on and near the fault than elsewhere in the model volume. The technique can be applied to non-planar faults by morphing, or smoothly distorting, the entire mesh to produce the desired 3-D fault geometry. Using our FaultMod finite-element software, we have tested grid-doubling with both slip-weakening and rate-and-state friction laws, by running the SCEC/ USGS 3-D dynamic rupture benchmark problems. We have also applied it to a model of the Hayward fault, Northern California, which uses realistic fault geometry and rock properties. FaultMod implements fault slip using common nodes, which represent motion common to both sides of the fault, and differential nodes, which represent motion of one side of the fault relative to the other side. We describe how to modify the traction-at-split-nodes method to work with common and differential nodes, using an implicit time stepping algorithm. ?? Journal compilation ?? 2009 RAS.

  6. An Improved Version of TOPAZ 3D

    SciTech Connect

    Krasnykh, Anatoly

    2003-07-29

    An improved version of the TOPAZ 3D gun code is presented as a powerful tool for beam optics simulation. In contrast to the previous version of TOPAZ 3D, the geometry of the device under test is introduced into TOPAZ 3D directly from a CAD program, such as Solid Edge or AutoCAD. In order to have this new feature, an interface was developed, using the GiD software package as a meshing code. The article describes this method with two models to illustrate the results.

  7. Examining microroughness evolution in natural and experimental pseudotachylyte-bearing fault surfaces

    NASA Astrophysics Data System (ADS)

    Shervais, Katherine; Castagna, Angela; Resor, Philip; Di Toro, Giulio; Griffith, W. Ashley; Nielsen, Stefan

    2013-04-01

    Fault surfaces are rough at all wavelengths, and power dissipation is therefore also likely to be highly heterogeneous during seismic slip along a single fault. We explore the relationship between the evolution of fault surface microroughness and power density, the product of slip rate with shear stress, taking two complimentary approaches: 1) measurement of roughness on experimentally generated pseudotachylytes (solidified frictional melts) where physical conditions can be carefully controlled and monitored and 2) 3D imaging of intact pseudotachylyte-bearing fault surfaces along a wavy fault surface where fault normal stress is inferred to vary with local fault orientation. Dynamic friction experiments performed with SHIVA, a rotary shear apparatus at the Instituto Nazionale di Geofisica in Rome, Italy, produce artificial pseudotachylyte under controlled conditions. The roughness of slip surfaces associated with these artificial pseudotachylytes was analyzed using images of thin sections produced from optical microscope and scanning electron microscopes (SEM). The edge of the pseudotachylyte was digitized and the characteristic height and radii of asperities were quantified. Analysis of the roughness of experimental pseudotachylytes suggests a decrease in characteristic asperity height with an increase in frictional power density. Natural pseudotachylyte-bearing faults preserve a record of roughness and, potentially, processes of wear and roughening during earthquake slip. By studying a fault with a relatively uniform slip magnitude but different orientation we can approximate the controlled conditions of dynamic friction experiments. In order to quantify fault surface microroughness and understand its evolution during slip we have examined the 3D geometry of samples from a single fault with approximately 110-200 mm of slip from within the Gole Larghe Fault Zone, Italy. At the outcrop scale, this fault is distinctly wavy with contractional and extensional fault bends as well as relatively straight sections. We quantified the micro-scale roughness for six samples from a range of geometric positions along the fault that we infer to have experienced different fault normal stress during slip. High-resolution x-ray computed tomography (CT) was used to image the internal geometry of the intact sample cores (2-3.5 cm in diameter, 4-6 cm in length). The surfaces of the fault zone were then extracted from the CT volume using an edge detection algorithm. The microroughness (sub mm to 10 cm scale) of the surfaces was then quantified using a Fourier spectral analysis. Samples from relatively planar sections of the fault show similar roughness on both sides, as do samples from contractional bends. Samples from extensional bends, however display distinctly different microroughness on each surface. Thus, samples from natural faults show an evolution of microroughness in response to changing conditions along the fault.

  8. 3D simulations of device performance for 3D-Trench electrode detector

    NASA Astrophysics Data System (ADS)

    Chen, Jianwei; Ding, Hao; Li, Zheng; Yan, Shaoan

    2015-10-01

    A square 3D-Trench electrode Si detector structure is simulated using a 3D TCAD tool. Electrical characteristics including electrostatic potential, electric field, leakage current, and capacitance have been simulated in detail. It has been found in simulations that both leakage current and the voltage to reach the geometry capacitance (full depletion voltage, Vfd) increase with radiation fluence. The geometry capacitance is 99 fF for the standard structure in our study. Detector geometry capacitance's dependence on the length and area of the collection column has also been simulated.

  9. 3D Magnetron simulation with CST STUDIO SUITE

    SciTech Connect

    Balk, Monika C.

    2011-07-01

    The modeling of magnetrons compared to other tubes is more difficult since it requires 3D modeling rather than a 2D investigation. This is not only due to the geometry which can include complicated details to be modeled in 3D but also due to the interaction process itself. The electric field, magnetic field and particle movement span a 3D space. In this paper 3D simulations of a strapped magnetron with CSTSTUDIO SUITE{sup TM} are presented. (author)

  10. Regional fault pattern study - Sonam/Ajapa area offshore Western Niger Delta

    SciTech Connect

    Kanu, K.A.; Glass, J.E.; Okoro, P.C.

    1995-08-01

    A total of 900 km{sup 2} of high quality 3-D data was used to interpret structural trends: an inner trend containing the Mefa, Meji and Ajapa oil fields and a younger outer trend containing the large Sonam condensate field. Each trend is bounded by a large, regional down-to-the-coast fault system on the northeast and its associated counter-regional fault to the southwest. Hydrocarbon accumulations are contained within rollover anticlines adjacent to the main seaward-dipping fault trends. However, our data shows that structural geometries within each trend are highly three-dimensional. Anticlinal end closure is achieved by changes in fault detachment level and displacement which generally occur near major fault junctions. Thus, significant accumulations are associated with first-order high-relief accommodation zones. In the absence of such first-order closure, we cannot rely upon the systems of relatively small faults that occur on seaward dipping flanks and in areas of crestal collapse. Detailed 3-D mapping, supported by drilling results, shows that such faults do not link strongly together, thereby allowing leakage of hydrocarbons mound fault tips and up relay ramps between faults.

  11. 3D Plasmon Ruler

    SciTech Connect

    2011-01-01

    In this animation of a 3D plasmon ruler, the plasmonic assembly acts as a transducer to deliver optical information about the structural dynamics of an attached protein. (courtesy of Paul Alivisatos group)

  12. The Mw 5.8 Mineral, Virginia, earthquake of August 2011 and aftershock sequence: constraints on earthquake source parameters and fault geometry

    USGS Publications Warehouse

    McNamara, Daniel E.; Benz, H.M.; Herrmann, Robert B.; Bergman, Eric A.; Earle, Paul; Meltzer, Anne; Withers, Mitch; Chapman, Martin

    2014-01-01

    The Mw 5.8 earthquake of 23 August 2011 (17:51:04 UTC) (moment, M0?5.7×1017??N·m) occurred near Mineral, Virginia, within the central Virginia seismic zone and was felt by more people than any other earthquake in United States history. The U.S. Geological Survey (USGS) received 148,638 felt reports from 31 states and 4 Canadian provinces. The USGS PAGER system estimates as many as 120,000 people were exposed to shaking intensity levels of IV and greater, with approximately 10,000 exposed to shaking as high as intensity VIII. Both regional and teleseismic moment tensor solutions characterize the earthquake as a northeast?striking reverse fault that nucleated at a depth of approximately 7±2??km. The distribution of reported macroseismic intensities is roughly ten times the area of a similarly sized earthquake in the western United States (Horton and Williams, 2012). Near?source and far?field damage reports, which extend as far away as Washington, D.C., (135 km away) and Baltimore, Maryland, (200 km away) are consistent with an earthquake of this size and depth in the eastern United States (EUS). Within the first few days following the earthquake, several government and academic institutions installed 36 portable seismograph stations in the epicentral region, making this among the best?recorded aftershock sequences in the EUS. Based on modeling of these data, we provide a detailed description of the source parameters of the mainshock and analysis of the subsequent aftershock sequence for defining the fault geometry, area of rupture, and observations of the aftershock sequence magnitude–frequency and temporal distribution. The observed slope of the magnitude–frequency curve or b?value for the aftershock sequence is consistent with previous EUS studies (b=0.75), suggesting that most of the accumulated strain was released by the mainshock. The aftershocks define a rupture that extends between approximately 2–8 km in depth and 8–10 km along the strike of the fault plane. Best?fit modeling of the geometry of the aftershock sequence defines a rupture plane that strikes N36°E and dips to the east?southeast at 49.5°. Moment tensor solutions of the mainshock and larger aftershocks are consistent with the distribution of aftershock locations, both indicating reverse slip along a northeast–southwest striking southeast?dipping fault plane.

  13. Characteristic fault zone architectures as result of different failure modes: first results from scale models of normal faulting

    NASA Astrophysics Data System (ADS)

    Kettermann, Michael; Urai, Janos L.

    2014-05-01

    It is known that fault zone architecture and structural style vary distinctly between tensile and shear failure modes, with strong effects on the associated fluid flow properties. A systematically comparative study in 3D has not been done so far, though. Inferring transport properties in sub-seismic scale from fault network geometries would have important applications in brittle lithologies such as carbonates or basalts. We present a method to investigate the structural properties of fault networks in 3D using cohesive hemihydrate powder (CaSO4 * 1/2H2O) embedded in two layers of dry fine grained sand. The material properties of the sand and powder are well known from previous studies. By increasing the overburden stress the failure mode of the powder can be changed from tensile to shear failure. Using hemihydrate powder allows us to harden and excavate the layer after the deformation by wetting the model slowly and brushing off the overburden sand. Visual investigation of the 3D structures is then possible in very high resolution. Analyses using photographs and 3D models from photogrammetry include qualitative observations as well as measurements of e.g. strike of fault segments, fault dip or graben width. We show a total of eight experiments that produce graben faults at four different overburden stresses (0, 1.5, 3, 6 cm overburden thickness) and at two increasing stages of strain (3 and 5 mm). In this set of models we describe two structural domains that show characteristic differences in their defining attributes. The tensile domain at small overburden stress (0 and 1.5 cm overburden) shows strongly dilatant faults with open fissures, vertical faults and large changes in strike at segment boundaries. The shear domain, formed by larger overburden stress (6 cm overburden), shows shallower fault dips around 65° with striations, numerous undulating fault branches and splays with low-angle fault intersections. Models with 3 cm overburden show a hybrid failure type with features from both structural domains. Using these attributes could enhance the prediction of fault network structures in the subsurface with interest in fields like fractured reservoirs or ore mineralization. Validation of these results with seismic and outcrop data is primary goal of the consecutive work.

  14. Salt-influenced normal fault growth and forced folding: The Stavanger Fault System, North Sea

    NASA Astrophysics Data System (ADS)

    Lewis, Matthew M.; Jackson, Christopher A.-L.; Gawthorpe, Rob L.

    2013-09-01

    Displacement ratio (Dr) is the ratio between salt thickness (Tv) and sub-salt normal fault displacement (D) (Dr = Tv/D), and it is typically used to predict the degree of geometric and kinematic linkage between sub- and supra-salt fault populations, and the overall structural style in salt-influenced extensional settings. However, we currently lack natural examples of how Dr and the underlying geological controls vary, and how these may control the three-dimensional geometry and evolution of salt-influenced normal fault systems. Furthermore, it is currently unknown if kinematic coherence in salt-influenced extensional settings can be maintained over relatively long length-scales (101-103 m) and for relatively long timeframes, and how this may impact the growth and geometry of large-throw (>500 m), salt-influenced normal fault systems. In this paper we use a 3600 km2, high-quality 3D seismic reflection dataset and borehole data from the Stavanger Fault System (SFS), Egersund Basin, eastern North Sea Basin to investigate; (i) how pre-rift salt thickness (Tv) and sub-salt fault throw (T) control the structural style and evolution of a basin-bounding, salt-influenced normal fault system; and (ii) the role salt plays in maintaining kinematic coherence in normal fault systems. We demonstrate that; (i) pre-rift salt distribution (Tv), specifically its presence in the proto-footwall (i.e., when Tv > 0), is the primary control on partitioning of faulting and (forced) folding along the fault system, and the style of linkage (i.e., hard- or soft-linkage) between sub- and supra-salt fault populations; and (ii) sub- and supra-salt fault populations represent brittle elements of a single, geometrically and kinematically coherent structure, the geometry and evolution of which is related to the ductile translation of strain on a scale (up to 8 km) and duration (c. 65 Myr) that believe is significantly greater and longer than previously documented.

  15. 3D Computer Vision and Video Computing 3D Vision3D Vision

    E-print Network

    Zhu, Zhigang

    3D Computer Vision and Video Computing 3D Vision3D Vision CSC I6716 Fall 2010 Topic 1 of Part II Camera Models Zhigang Zhu, City College of New York zhu@cs.ccny.cuny.edu #12;3D Computer Vision and Video Computing 3D Vision3D Vision Closely Related Disciplines Image Processing ­ images to mages Computer

  16. 3D Computer Vision and Video Computing 3D Vision3D Vision

    E-print Network

    Zhu, Zhigang

    1 3D Computer Vision and Video Computing 3D Vision3D Vision Topic 1 of Part II Camera Models CSC I6716 Spring2011 Zhigang Zhu, City College of New York zhu@cs.ccny.cuny.edu 3D Computer Vision and Video Computing 3D Vision3D Vision Closely Related Disciplines Image Processing ­ images to mages Computer

  17. FEM-based linear inverse modeling using a 3D source array to image magma chambers with free geometry. Application to InSAR data from Rabaul Caldera (PNG).

    NASA Astrophysics Data System (ADS)

    Ronchin, Erika; Masterlark, Timothy; Dawson, John; Saunders, Steve; Martí Molist, Joan

    2015-04-01

    In this study, we present a method to fully integrate a family of finite element models (FEMs) into the regularized linear inversion of InSAR data collected at Rabaul caldera (PNG) between February 2007 and December 2010. During this period the caldera experienced a long-term steady subsidence that characterized surface movement both inside the caldera and outside, on its western side. The inversion is based on an array of FEM sources in the sense that the Green's function matrix is a library of forward numerical displacement solutions generated by the sources of an array common to all FEMs. Each entry of the library is the LOS surface displacement generated by injecting a unity mass of fluid, of known density and bulk modulus, into a different source cavity of the array for each FEM. By using FEMs, we are taking advantage of their capability of including topography and heterogeneous distribution of elastic material properties. All FEMs of the family share the same mesh in which only one source is activated at the time by removing the corresponding elements and applying the unity fluid flux. The domain therefore only needs to be discretized once. This precludes remeshing for each activated source, thus reducing computational requirements, often a downside of FEM-based inversions. Without imposing an a-priori source, the method allows us to identify, from a least-squares standpoint, a complex distribution of fluid flux (or change in pressure) with a 3D free geometry within the source array, as dictated by the data. The results of applying the proposed inversion to Rabaul InSAR data show a shallow magmatic system under the caldera made of two interconnected lobes located at the two opposite sides of the caldera. These lobes could be consistent with feeding reservoirs of the ongoing Tavuvur volcano eruption of andesitic products, on the eastern side, and of the past Vulcan volcano eruptions of more evolved materials, on the western side. The interconnection and spatial distribution of sources find correspondence in the petrography of the volcanic products described in literature and in the dynamics of the single and twin eruptions that characterize the caldera. As many other volcanoes, Rabaul caldera is an active and dangerous volcanic system whose dynamics still need to be understood to effectively predict the behavior of future eruptions. The good results obtained from the application of the method to Rabaul caldera show that the proposed linear inversion based on the FEM array of sources is suitable to generate models of magmatic systems. The method can image in space and time the complex free geometry of the source that generates the deformation, widening our understanding of deformational sources and their dynamics. This takes source modeling a step towards more realistic source models.

  18. The X3D grid generation system

    SciTech Connect

    Trease, H.; George, D.; Gable, C.; Fowler, J.; Linnbur, E.

    1996-12-31

    X3D is the grid generation system that we use at Los Alamos and is designed for multimaterial, time-dependent, 3-D hybrid grids that are either statically adapted or evolved in time. It`s capabilities includes static and dynamic grids, hybrid grids, managing colliding surfaces, grid optimization (using reconnections, smoothing, and adaptive mesh refinement (AMR) algorithms). The X3D`s data structure can manage an arbitrary number of {open_quotes}grid objects{close_quotes} each with an arbitrary number of grid attributes. X3D uses surface geometry to build volumes by using combinations of logical and boolean operators. Point distributions can be input, generated using ray shooting techniques or defined point-by-point. Connectivity matrices are then generated automatically for all variations of hybrid grids.

  19. The Galicia 3D experiment: an Introduction.

    NASA Astrophysics Data System (ADS)

    Reston, Timothy; Martinez Loriente, Sara; Holroyd, Luke; Merry, Tobias; Sawyer, Dale; Morgan, Julia; Jordan, Brian; Tesi Sanjurjo, Mari; Alexanian, Ara; Shillington, Donna; Gibson, James; Minshull, Tim; Karplus, Marianne; Bayracki, Gaye; Davy, Richard; Klaeschen, Dirk; Papenberg, Cord; Ranero, Cesar; Perez-Gussinye, Marta; Martinez, Miguel

    2014-05-01

    In June and July 2013, scientists from 8 institutions took part in the Galicia 3D seismic experiment, the first ever crustal -scale academic 3D MCS survey over a rifted margin. The aim was to determine the 3D structure of a critical portion of the west Galicia rifted margin. At this margin, well-defined tilted fault blocks, bound by west-dipping faults and capped by synrift sediments are underlain by a bright reflection, undulating on time sections, termed the S reflector and thought to represent a major detachment fault of some kind. Moving west, the crust thins to zero thickness and mantle is unroofed, as evidence by the "Peridotite Ridge" first reported at this margin, but since observed at many other magma-poor margins. By imaging such a margin in detail, the experiment aimed to resolve the processes controlling crustal thinning and mantle unroofing at a type example magma poor margin. The experiment set out to collect several key datasets: a 3D seismic reflection volume measuring ~20x64km and extending down to ~14s TWT, a 3D ocean bottom seismometer dataset suitable for full wavefield inversion (the recording of the complete 3D seismic shots by 70 ocean bottom instruments), the "mirror imaging" of the crust using the same grid of OBS, a single 2D combined reflection/refraction profile extending to the west to determine the transition from unroofed mantle to true oceanic crust, and the seismic imaging of the water column, calibrated by regular deployment of XBTs to measure the temperature structure of the water column. We collected 1280 km2 of seismic reflection data, consisting of 136533 shots recorded on 1920 channels, producing 260 million seismic traces, each ~ 14s long. This adds up to ~ 8 terabytes of data, representing, we believe, the largest ever academic 3D MCS survey in terms of both the area covered and the volume of data. The OBS deployment was the largest ever within an academic 3D survey.

  20. Radiochromic 3D Detectors

    NASA Astrophysics Data System (ADS)

    Oldham, Mark

    2015-01-01

    Radiochromic materials exhibit a colour change when exposed to ionising radiation. Radiochromic film has been used for clinical dosimetry for many years and increasingly so recently, as films of higher sensitivities have become available. The two principle advantages of radiochromic dosimetry include greater tissue equivalence (radiologically) and the lack of requirement for development of the colour change. In a radiochromic material, the colour change arises direct from ionising interactions affecting dye molecules, without requiring any latent chemical, optical or thermal development, with important implications for increased accuracy and convenience. It is only relatively recently however, that 3D radiochromic dosimetry has become possible. In this article we review recent developments and the current state-of-the-art of 3D radiochromic dosimetry, and the potential for a more comprehensive solution for the verification of complex radiation therapy treatments, and 3D dose measurement in general.

  1. 3D Model of the Neal Hot Springs Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    The Neal Hot Springs geothermal system lies in a left-step in a north-striking, west-dipping normal fault system, consisting of the Neal Fault to the south and the Sugarloaf Butte Fault to the north (Edwards, 2013). The Neal Hot Springs 3D geologic model consists of 104 faults and 13 stratigraphic units. The stratigraphy is sub-horizontal to dipping <10 degrees and there is no predominant dip-direction. Geothermal production is exclusively from the Neal Fault south of, and within the step-over, while geothermal injection is into both the Neal Fault to the south of the step-over and faults within the step-over.

  2. Impact of pre- and/or syn-tectonic salt layers in the hangingwall geometry of a kinked-planar extensional fault: insights from analogue modelling and comparison with the Parentis basin (bay of Biscay)

    NASA Astrophysics Data System (ADS)

    Ferrer, O.; Vendeville, B. C.; Roca, E.

    2012-04-01

    Using sandbox analogue modelling we determine the role played by a pre-kinematic or a syn-kinematic viscous salt layer during rollover folding of the hangingwall of a normal fault with a variable kinked-planar geometry, as well as understand the origin and the mechanisms that control the formation, kinematic evolution and geometry of salt structures developed in the hangingwall of this fault. The experiments we conducted consisted of nine models made of dry quartz-sand (35?m average grain size) simulating brittle rocks and a viscous silicone polymer (SMG 36 from Dow Corning) simulating salt in nature. The models were constructed between two end walls, one of which was fixed, whereas the other was moved by a motor-driven worm screw. The fixed wall was part of the rigid footwall of the model's master border fault. This fault was simulated using three different wood block configurations, which was overlain by a flexible (but not stretchable) sheet that was attached to the mobile endwall of the model. We applied three different infill hangingwall configurations to each fault geometry: (1) without silicone (sand only), (2) sand overlain by a pre-kinematic silicone layer deposited above the entire hanginwall, and (3) sand partly overlain by a syn-kinematic silicone layer that overlain only parts of the hangingwall. All models were subjected to a 14 cm of basement extension in a direction orthogonal to that of the border fault. Results show that the presence of a viscous layer (silicone) clearly controls the deformation pattern of the hangingwall. Thus, regardless of the silicone layer's geometry (either pre- or syn-extensional) or the geometry of the extensional fault, the silicone layer acts as a very efficient detachment level separating two different structural styles in each unit. In particular, the silicone layer acts as an extensional ductile shear zone inhibiting upward propagation of normal faults and/or shears bands from the sub-silicone layers. Whereas the basement is affected by antithetic normal faults that are more or less complex depending on the geometry of the master fault, the lateral flow of the silicone produces salt-cored anticlines, walls and diapirs in the overburden of the hangingwall. The mechanical behavior of the silicone layer as an extensional shear zone, combined with the lateral changes in pressure gradients due to overburden thickness changes, triggered the silicone migration from the half-graben depocenter towards the rollover shoulder. As a result, the accumulation of silicone produces gentle silicone-cored anticlines and local diapirs with minor extensional faults. Upwards fault propagation from the sub-silicone "basement" to the supra-silicone unit only occurs either when the supra- and sub-silicone materials are welded, or when the amount of slip along the master fault is large enough so that the tip of the silicone reaches the junction between the upper and lower panels of the master faults. Comparison between the results of these models with data from the western offshore Parentis Basin (Eastern Bay of Biscay) validates the structural interpretation of this region.

  3. Design of 3D-Printed Titanium Compliant Mechanisms

    NASA Technical Reports Server (NTRS)

    Merriam, Ezekiel G.; Jones, Jonathan E.; Howell, Larry L.

    2014-01-01

    This paper describes 3D-printed titanium compliant mechanisms for aerospace applications. It is meant as a primer to help engineers design compliant, multi-axis, printed parts that exhibit high performance. Topics covered include brief introductions to both compliant mechanism design and 3D printing in titanium, material and geometry considerations for 3D printing, modeling techniques, and case studies of both successful and unsuccessful part geometries. Key findings include recommended flexure geometries, minimum thicknesses, and general design guidelines for compliant printed parts that may not be obvious to the first time designer.

  4. 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 seismic estimates for the Eureka Valley and Aiquile earthquakes, the seismic data are found to be compatible with the InSAR location. A 30° difference in strike between InSAR and seismic-derived source models is also resolved when taking 3-D Earth structure into account in the analysis of the Eureka Valley earthquake. The combination of both InSAR and seismic data further constrains the dip for the Zarand earthquake, and in all cases the seismic moment is more robustly constrained in the joint inversions than in the individual data set inversions. Unmodelled lateral heterogeneities in Earth and the models could partly explain some of the observed source parameter discrepancies related to the seismic data.

  5. 3-D numerical modelling of the influence of reactivated pre-existing faults on the distribution of deformation: example of North-Western Ghana around 2.15-2.00 Ga

    NASA Astrophysics Data System (ADS)

    FENG, Xiaojun; Gerbault, Muriel; Martin, Roland; Ganne, Jérôme; Jessell, Mark

    2015-04-01

    High strain zones appear to play a significant role in feeding the upper crust with fluids and partially molten material from lower crust sources. The Bole-Bulenga terrain (North-Western Ghana) is located in between two subvertical shear zones, and mainly consists of high-grade orthogneisses, paragneisses and metabasites intruded by partially molten lower crustal material with monzogranites and orthogneisses (Eburnean orogeny, around 2.1 Ga). In order to understand the location of these high grade rocks at the edges and in between these two shear zones, a three dimensional numerical model was built to test the influence of different orientations of a system of branched strike-slip faults on visco-plastic deformation, under compressional and simple shear boundary conditions. Our models indicate domains of tensile vs. compressional strain as well as shear zones, and show that not only internal fault zones but also the host rock in between the faults behave relatively softer than external regions. Under both applied compressive and simple shear boundary conditions, these softened domains constitute preferential zones of tensile strain accommodation (dilation) in the upper crust, which may favor infilling by deeper partially molten rocks. Our modeled pre-existing faults zones are assumed to have formed during an early D1 stage of deformation, and they are shown to passively migrate and rotate together with the solid matrix under applied external boundary conditions (corresponding to a post D1 - early D2 phase of deformation). We suggest that in the Bole-Bulenga terrain, fluids or partially molten material stored in deeper crustal domains, preferentially intruded the upper crust within these highly (shear and tensile) strained domains, thanks to this D2 shearing deformation phase. Building relief at the surface is primarily controlled by fault orientations, together with mechanical parameters and external boundary conditions. In particular, greatest magnitudes of relief are obtained when faults dip in parallel one with the other and when they are inclined at depth, as they thus facilitate stress rotation and material transfer from depth. The host rock density does not play a primary role in producing relief compared to variations in friction angle at the crustal scale (30km thick). Relief increases by 200 - 300 m when the host rock density is increased by 200 kg/m3 , whereas relief drops by about 1200 m when decreasing the host rock friction from ? = 20° to 10°.

  6. Urbanisation and 3d Spatial - a Geometric Approach

    NASA Astrophysics Data System (ADS)

    Duncan, E. E.; Rahman, A. Abdul

    2013-09-01

    Urbanisation creates immense competition for space, this may be attributed to an increase in population owing to domestic and external tourism. Most cities are constantly exploring all avenues in maximising its limited space. Hence, urban or city authorities need to plan, expand and use such three dimensional (3D) space above, on and below the city space. Thus, difficulties in property ownership and the geometric representation of the 3D city space is a major challenge. This research, investigates the concept of representing a geometric topological 3D spatial model capable of representing 3D volume parcels for man-made constructions above and below the 3D surface volume parcel. A review of spatial data models suggests that the 3D TIN (TEN) model is significant and can be used as a unified model. The concepts, logical and physical models of 3D TIN for 3D volumes using tetrahedrons as the base geometry is presented and implemented to show man-made constructions above and below the surface parcel within a user friendly graphical interface. Concepts for 3D topology and 3D analysis are discussed. Simulations of this model for 3D cadastre are implemented. This model can be adopted by most countries to enhance and streamline geometric 3D property ownership for urban centres. 3D TIN concept for spatial modelling can be adopted for the LA_Spatial part of the Land Administration Domain Model (LADM) (ISO/TC211, 2012), this satisfies the concept of 3D volumes.

  7. 4D modelling of the Alto Tiberina Fault system (Northern Apennines, Italy)

    NASA Astrophysics Data System (ADS)

    De Donatis, Mauro; Susini, Sara; Mirabella, Francesco; Lupattelli, Andrea; Barchi, Massimiliano

    2014-05-01

    The Alto Tiberina Fault (ATF) in the Northern Apennines of Italy is a low-angle normal fault dipping to the East and accommodating up to 10 km of extension. The fault is ~70 km long and is the detachment for the SW-dipping Gubbio normal fault. The ATF fault system has been dramatically exhumed and the ATF footwall has evolved in a horst bounded to the east by ATF synthetic faults and to the west by the Corciano west-dipping normal fault. The fault has been widely studied over the last years in order to understand its mechanical behaviour, its present-day deformation rate and its seismological role. By using a wide data-set including subsurface data (seismic reflection profiles and boreholes) and surface geological data (new maps of the CARG project of Italy), we have reconstructed the 3D geometry of both the fault and of the main lithostratigraphic boundaries at the fault hanging-wall and foot-wall. The CARG map data were integrated by local observations and mapping using mobile GIS software (BeeGIS) and Android app (Geopaparazzi). Surface data were combined with seismic reflection profiles and wells interpretation and other data from available literature. The large amount of information were combined in MOVE software (Midland Valley Exploration ltd). Our reconstruction allows to i) build up a three-dimensional geological model of the subsurface including the main faults and lithostratigraphic boundaries; ii) identify a set of east-west trending faults the role of which was previously underestimated; iii) test a 3D-restoration of extension for the visualization of the time evolution and for the validation of the structural reconstruction. The restored structures are the main normal faults in the region. The sequential restoration was performed by taking into account the timing of deformation as derived from the literature. The model was sequentially restored according to the following chronological order from the latest to the oldest: 1a) last deformational event along Gubbio Normal Fault on ATF coeval with 1b) latest event along Corciano fault and 2) ATF detachment fault activity. The resulting maximum values of displacements has been calculated as: 1a) about 2300m with a throw of about 1600m (measured in the 3D model on the top of Carbonates surfaces cut off); 1b) about 1900m for the slip and 2900m for the throw (measured along this fault both on the top of Carbonates as on acoustic Basement cut off); 2) 8 km of maximum extension measured between Umbertide e Citta' di Castello and progressively decreases toward NW and SW.

  8. Extra Dimensions: 3D in PDF Documentation

    NASA Astrophysics Data System (ADS)

    Graf, Norman A.

    2012-12-01

    Experimental science is replete with multi-dimensional information which is often poorly represented by the two dimensions of presentation slides and print media. Past efforts to disseminate such information to a wider audience have failed for a number of reasons, including a lack of standards which are easy to implement and have broad support. Adobe's Portable Document Format (PDF) has in recent years become the de facto standard for secure, dependable electronic information exchange. It has done so by creating an open format, providing support for multiple platforms and being reliable and extensible. By providing support for the ECMA standard Universal 3D (U3D) and the ISO PRC file format in its free Adobe Reader software, Adobe has made it easy to distribute and interact with 3D content. Until recently, Adobe's Acrobat software was also capable of incorporating 3D content into PDF files from a variety of 3D file formats, including proprietary CAD formats. However, this functionality is no longer available in Acrobat X, having been spun off to a separate company. Incorporating 3D content now requires the additional purchase of a separate plug-in. In this talk we present alternatives based on open source libraries which allow the programmatic creation of 3D content in PDF format. While not providing the same level of access to CAD files as the commercial software, it does provide physicists with an alternative path to incorporate 3D content into PDF files from such disparate applications as detector geometries from Geant4, 3D data sets, mathematical surfaces or tesselated volumes.

  9. High-Frequency Radiation from an Earthquake Fault: A Review and a Hypothesis of Fractal Rupture Front Geometry

    NASA Astrophysics Data System (ADS)

    Gusev, A. A.

    2013-01-01

    Observed high-frequency (HF) radiation from earthquake faults exhibits specific properties that cannot be deduced or extrapolated from low-frequency fault behavior. In particular: (1) HF time functions look like random signals, with smooth mean spectrum and moderately heavy-tailed probability distribution function for amplitudes; (2) well-known directivity of low-frequency radiation related to rupture propagation is strongly reduced at HF, suggesting incoherent (delta-correlated) behavior of the HF radiator, and contradicting the usual picture of a rupture front as a regular, non-fractal moving line; (3) in the spectral domain, HF radiation occupies a certain specific band seen as a plateau on acceleration source spectra K(f) = f2 dot{M}0 (f) . The lower cutoff frequency f b of K(f) spectra is often located significantly higher than the common spectral corner frequency f c, or f a. In many cases, empirical f b( M 0) trends are significantly slower as compared to the simple f b ? M {0/-1/3}, testifying the lack of similarity in spectral shapes; (4) evidence is accumulating in support of the reality of the upper cutoff frequency of K(f): fault-controlled f max, or f uf. However, its identification is often hampered by such problems as: (a) strong interference between f uf and site-controlled f max; (b) possible location of f uf above the observable spectral range; and (c) substantial deviations of individual source spectra from the ideal spectral shape; (5) intrinsic structure of random-like HF radiation has been shown to bear significant self-similar (fractal) features. A HF signal can be represented as a product of a random HF "carrier signal" with constant mean square amplitude, and a positive modulation function, again random, that represents a signal envelope. It is this modulation function that shows approximately fractal behavior. This kind of behavior was revealed over a broad range of time scales, from 1 to 300 s from teleseismic data and from 0.04 to 30 s from near-fault accelerogram data. To explain in a qualitative way many of these features, it is proposed that rupture propagation can be visualized as occurring, simultaneously, at two different space-time scales. At a macro-scale (i.e. at a low resolution view), one can safely believe in the reality of a singly connected rupture with a front as a smooth line, like a crack tip, that propagates in a locally unilateral way. At a micro-scale, the rupture front is tortuous and disjoint, and can be visualized as a multiply connected fractal "line" or polyline. It propagates, locally, in random directions, and is governed by stochastic regularities, including fractal time structure. The two scales and styles are separated by a certain characteristic time, of the order of (0.07-0.15) × rupture duration. The domain of fractal behavior spans a certain HF frequency range; its boundaries, related to the lower and upper fractal limits, are believed to be manifested as f b and f uf.

  10. Earthquakes, Segments, Bends, and Fault-Face Geology: Correlations Within the San Andreas System, California

    NASA Astrophysics Data System (ADS)

    Jachens, R. C.; Simpson, R. W.; Thurber, C. H.; Murray, J. R.

    2006-12-01

    Three-dimensional geologic maps of regions surrounding parts of the San Andreas Fault system reveal correlations between fault face geology and both short- and long-term behavior of the faults. The Loma Prieta fault segment that ruptured during the 1989 M6.9 earthquake, as defined by its aftershocks, closely corresponds to the subsurface reach (80 km long) where a large body of Logan gabbro is truncated at the fault, as defined by its magnetic anomaly. This Jurassic ophiolitic gabbro and its related rocks occupy an unusual fault-bounded basement block within Salinaa, a largely Cretaceous granitic terrane SW of the San Andreas Fault. The along-fault reach of the Logan gabbro also coincides with essentially the entire Santa Cruz Mountains left-bend in the San Andreas Fault. Rejecting a chance coincidence, the position of the Logan gabbro with respect to the left bend implies that the bend is fixed relative to Salinia and that the block NE of the San Andreas Fault has been forced to negotiate around the bend as the blocks moved past each other. Thus the basement rocks of the Logan block appear to define (control?) the Loma Prieta segment in terms both of short-term behavior (earthquakes) and long-term behavior (restraining bend fault geometry). The Parkfield segment of the San Andreas Fault also closely corresponds to a characteristic geologic unit in the NE face of the fault, the greenstone-rich Permanente terrane of the Franciscan Complex. The along-fault subsurface extent of the Permanente terrane at the fault face, as inferred from a recent 3D tomographic wavespeed model, corresponds to the reach filled by the aftershocks of the 2004 Parkfield earthquake. Furthermore, the 2004 co-seismic slip inferred from geodetic observations also coincides with the Permanente terrane at the fault face. To test whether these observations are directly related to the presence of the Permanente terrane along the fault face, we looked at fault behavior at the location of its offset counterpart, which truncates at the Calaveras Fault near Hollister 175 km to the NW. Here, the along-fault subsurface extent of the Permanente terrane, as defined by its gravity and magnetic anomalies, corresponds to the aftershock distribution of the 1979 Coyote Lake earthquake, giving support to the idea that fault-face geology can influence fault behavior and control fault segmentation.

  11. FARGO3D: Hydrodynamics/magnetohydrodynamics code

    NASA Astrophysics Data System (ADS)

    Benítez Llambay, Pablo; Masset, Frédéric

    2015-09-01

    A successor of FARGO (ascl:1102.017), FARGO3D is a versatile HD/MHD code that runs on clusters of CPUs or GPUs, with special emphasis on protoplanetary disks. FARGO3D offers Cartesian, cylindrical or spherical geometry; 1-, 2- or 3-dimensional calculations; and orbital advection (aka FARGO) for HD and MHD calculations. As in FARGO, a simple Runge-Kutta N-body solver may be used to describe the orbital evolution of embedded point-like objects. There is no need to know CUDA; users can develop new functions in C and have them translated to CUDA automatically to run on GPUs.

  12. 3-D Crustal Structure in Southwestern China

    NASA Astrophysics Data System (ADS)

    Wang, C.; Chan, W.; Mooney, W.

    2001-12-01

    Using P and S arrival data of 4,625 local and regional earthquakes recorded at 174 seismic stations and associated geophysical investigation, we present a 3-D crustal and upper mantle velocity structure of the southwestern China (Sichuan and Yunnan provinces). The southwestern China lies in the transition zone between the uplifted Tibetan plateau to the west and the Yangtze continental platform to the east. In the upper crust, a positive anomaly velocity zone exists in the Sichuan basin; whereas a large-scale negative anomaly velocity zone exists in the western Sichuan plateau, which is consistent with the upper crustal structure under Tibetan Plateau. The boundary between these two positive and negative anomaly zones is the Longmen Shan fault. The Tengchong volcanic area, as well as the strike-slip faults, such as Xianshuihe fault, Anninghe fault, the northern segment of Red River fault, and the southern segment of Xiaojiang fault, are in the areas with a negative anomaly zone in the upper crust. In the mid-crustal depth, we found that there is a general consistency between the negative velocity anomaly and seismicity. The negative velocity anomalies at the depth of 50 km in the Tengchong volcanic area and the Panxi tectonic zone appears to be associated with the temperature and composition variations in the upper mantle. The Red River fault is the boundary between the positive and negative velocity anomalies at 50 km depth. The overall features of the crustal and the upper mantle structures in the southwestern China are the low average velocity, the large crustal thickness variations, the existence of a high conductivity layer in the crust or/and upper mantle, and a high geothermal value. All these features are closely related to the collision between the Indian and the Asian plates.

  13. 3d X 3d X SrTiO3Ti 2p 3d

    E-print Network

    Katsumoto, Shingo

    XX 3d X 3d X X XX X XX SrTiO3Ti 2p 3d SrTiO3Ti 2p 3d 2p 2p SrTiO3 ts) 2p3/2 (t2g) 2p3/2 (e ) 2p1/2 (eg)2p SrTiO3 3d unit (t2g) (eg) (eg)2p1/2 (t2g)3d (Ti Fe Cu) arb. ( 2g) (Ti, Fe, Cu) y(ansitynten 3d In 3d 468464460456 · Photon Energy (e

  14. DYNA3D

    SciTech Connect

    Kennedy, T. )

    1989-05-01

    DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature-dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, and resultant plasticity. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 equations of state including linear polynomial, JWL high explosive, Sack 'Tuesday' high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interface data for contact surfaces.

  15. Efficient Computation of Casimir Interactions between Arbitrary 3D Objects

    E-print Network

    White, Jacob K.

    We introduce an efficient technique for computing Casimir energies and forces between objects of arbitrarily complex 3D geometries. In contrast to other recently developed methods, our technique easily handles nonspheroidal, ...

  16. 3D Model of the Tuscarora Geothermal Area

    DOE Data Explorer

    Faulds, James E.

    2013-12-31

    The Tuscarora geothermal system sits within a ~15 km wide left-step in a major west-dipping range-bounding normal fault system. The step over is defined by the Independence Mountains fault zone and the Bull Runs Mountains fault zone which overlap along strike. Strain is transferred between these major fault segments via and array of northerly striking normal faults with offsets of 10s to 100s of meters and strike lengths of less than 5 km. These faults within the step over are one to two orders of magnitude smaller than the range-bounding fault zones between which they reside. Faults within the broad step define an anticlinal accommodation zone wherein east-dipping faults mainly occupy western half of the accommodation zone and west-dipping faults lie in the eastern half of the accommodation zone. The 3D model of Tuscarora encompasses 70 small-offset normal faults that define the accommodation zone and a portion of the Independence Mountains fault zone, which dips beneath the geothermal field. The geothermal system resides in the axial part of the accommodation, straddling the two fault dip domains. The Tuscarora 3D geologic model consists of 10 stratigraphic units. Unconsolidated Quaternary alluvium has eroded down into bedrock units, the youngest and stratigraphically highest bedrock units are middle Miocene rhyolite and dacite flows regionally correlated with the Jarbidge Rhyolite and modeled with uniform cumulative thickness of ~350 m. Underlying these lava flows are Eocene volcanic rocks of the Big Cottonwood Canyon caldera. These units are modeled as intracaldera deposits, including domes, flows, and thick ash deposits that change in thickness and locally pinch out. The Paleozoic basement of consists metasedimenary and metavolcanic rocks, dominated by argillite, siltstone, limestone, quartzite, and metabasalt of the Schoonover and Snow Canyon Formations. Paleozoic formations are lumped in a single basement unit in the model. Fault blocks in the eastern portion of the model are tilted 5-30 degrees toward the Independence Mountains fault zone. Fault blocks in the western portion of the model are tilted toward steeply east-dipping normal faults. These opposing fault block dips define a shallow extensional anticline. Geothermal production is from 4 closely-spaced wells, that exploit a west-dipping, NNE-striking fault zone near the axial part of the accommodation zone.

  17. 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] ). PMID:26440264

  18. Dynamic evolution of a fault system through interactions between fault segments

    E-print Network

    Yamashita, Teruo

    Dynamic evolution of a fault system through interactions between fault segments Ryosuke Ando 2004; published 18 May 2004. [1] We simulate the dynamic evolution process of fault system geometry geometry Citation: Ando, R., T. Tada, and T. Yamashita (2004), Dynamic evolution of a fault system through

  19. Creating Entirely Textured 3D Models of Real Objects Using Surface Flattening

    E-print Network

    Chetverikov, Dmitry

    ). Obtaining the 3D model of an object can be achieved by various 3D scanners, most frequently by laser are independent: precise geometry is provided by a 3D laser scanner, while textures are obtained from high qualityCreating Entirely Textured 3D Models of Real Objects Using Surface Flattening Zsolt Jank´o, G´eza K

  20. Migrating from 2D to 3D in "Autograph"

    ERIC Educational Resources Information Center

    Butler, Douglas

    2006-01-01

    With both "Cabri" and "Autograph" now venturing into 3D, the dimension that previously was only demonstrated in the classroom with a lot of arm waving and crude wire cages can now be explored dynamically on screen. "Cabri 3D" concentrates on constructions, using the principles of Euclidian geometry, whereas "Autograph" creates objects using a…

  1. 3D interactive pictorial maps 

    E-print Network

    Naz, Asma

    2005-02-17

    these maps interactive on the Web and have them accessible to a large number of viewers. The results show a number of interactive 3D pictorial maps of different countries and continents. These maps are initially built with Maya, a 3D modeling software... of simplififcation and exaggeration.. . . . . . . . . . . . . . 21 8 3D polygonal text in Maya. . . . . . . . . . . . . . . . . . . . . . . . 22 9 Final 3D model of Italy with text. . . . . . . . . . . . . . . . . . . . 23 10 Top view of 3D model of France...

  2. THE STATUS OF TODAYS DESCRIPTIVE GEOMETRY RELATED EDUCATION

    E-print Network

    Nawratil, Georg

    is carried out in European countries. By definition, Descriptive Geometry is a method to study 3D geometry: `Descriptive Geometry' is a method #12;2 to study 3D geometry through 2D images. It provides insight Geometry is the interplay · between the 3D situation and its 2D repre- sentation, and · between intuitive

  3. Genesis and growth of the NW trending normal fault array of the Levant Basin

    NASA Astrophysics Data System (ADS)

    Ghalayini, Ramadan; Homberg, Catherine; Daniel, Jean-Marc; Nader, Fadi

    2015-04-01

    The Levant basin, located in the Eastern Mediterranean region, presents a conspicuous normal fault array in the interpreted Oligo-Miocene units. How did the faults grow, evolve and interact with each other is important in order to increase our understanding on the growth of normal fault systems in general and the structural setting of the Levant Basin in particular. Found offshore Lebanon, and partly offshore SE Cyprus and Israel, these faults are layer bound and comprised only in the Oligo-Miocene units, bounded by the base Messinian horizon and Eocene unconformity horizon at their top and bottom respectively. They correlate well with the thickness of the Oligo-Miocene sediments which might explain their distribution. Quantitative and qualitative fault analysis techniques were applied to a 3D seismic reflection dataset. Deduced thickness variations at the Miocene interval (across the faults) and growth index calculations show that the motion of these faults is syn-sedimentary since the Early Miocene time. As observed in cross-section; most of the faults are throughgoing faults and do not show significant refraction or bifurcation. However, the displacement data show that the fault history is complex and imply that the Cenozoic package is characterized by a significant mechanical layering. The latter has influenced the fault development with preferential and double nucleation sites of fault segments which later linked by vertical tip propagation. An asymmetry in the upward and downward vertical restriction is also deduced and horizontal linkages also occurred. The various geometric observations and displacement distribution indicate a strong resemblance between the normal faults of the Levant Basin and the widely documented polygonal fault systems. As polygonal faults are characterized by polygonal planform geometry and the faults in the Levant Basin are linear, we attribute the difference in their planform geometry to a regional anisotropic NW-SE stress field dominant since Oligocene times. These faults are thus possibly formed in relation with the vertical contraction of the fine-grained host rock unit with the conjunction of a complex fluid pressure profile in the sedimentary pile. Our interpretation suggested that growth of contractional faults on a basin-scale generally follows the isolated model, at least in their early history, accumulating length proportionally with displacement. When subject to an anisotropic regional stress field, they will grow very similarly to normal tectonic faults, being then influenced by mutual interaction and mechanical layering.

  4. INGRID; 3-D Mesh Generation Nonlinear Systems

    SciTech Connect

    Stillman, D.W.; Rainsberger, R.

    1985-07-01

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surface equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.

  5. INGRID. 3-D Mesh Generation Nonlinear Systems

    SciTech Connect

    Stillman, D.W.; Rainsberger, R.

    1985-07-01

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surface equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.

  6. INGRID. 3-D Mesh Generation Nonlinear Systems

    SciTech Connect

    Stillman, D.W.; Rainsberger, R.

    1985-07-01

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D (ESTSC. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surface equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.

  7. INGRID. 3-D Mesh Generation Nonlinear Systems

    SciTech Connect

    Christon, M.A.; Dovey, D.; Stillman, D.W.; Hallquist, J.O.; Rainsberger, R.B. )

    1992-09-01

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surface equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.

  8. 3-D Finite Element Heat Transfer

    Energy Science and Technology Software Center (ESTSC)

    1992-02-01

    TOPAZ3D is a three-dimensional implicit finite element computer code for heat transfer analysis. TOPAZ3D can be used to solve for the steady-state or transient temperature field on three-dimensional geometries. Material properties may be temperature-dependent and either isotropic or orthotropic. A variety of time-dependent and temperature-dependent boundary conditions can be specified including temperature, flux, convection, and radiation. By implementing the user subroutine feature, users can model chemical reaction kinetics and allow for any type of functionalmore »representation of boundary conditions and internal heat generation. TOPAZ3D can solve problems of diffuse and specular band radiation in an enclosure coupled with conduction in the material surrounding the enclosure. Additional features include thermal contact resistance across an interface, bulk fluids, phase change, and energy balances.« less

  9. 3D Audio System

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Ames Research Center research into virtual reality led to the development of the Convolvotron, a high speed digital audio processing system that delivers three-dimensional sound over headphones. It consists of a two-card set designed for use with a personal computer. The Convolvotron's primary application is presentation of 3D audio signals over headphones. Four independent sound sources are filtered with large time-varying filters that compensate for motion. The perceived location of the sound remains constant. Possible applications are in air traffic control towers or airplane cockpits, hearing and perception research and virtual reality development.

  10. 3-D Color Wheels

    ERIC Educational Resources Information Center

    DuBois, Ann

    2010-01-01

    The blending of information from an academic class with projects from art class can do nothing but strengthen the learning power of the student. Creating three-dimensional color wheels provides the perfect opportunity to combine basic geometry knowledge with color theory. In this article, the author describes how her seventh-grade painting…

  11. Ductile Faults Control Seismogenic Movement on Oceanic Transforms

    NASA Astrophysics Data System (ADS)

    Lister, G. S.; Tkalcic, H.; Forster, M. A.; McClusky, S.

    2014-12-01

    Structural Geology is about 3D geometry and the symphony of kinematically-coordinated movement. In this case we discuss patterns of violent relative displacement inferred from focal plane data for earthquakes. Systematic stereographic analysis of centroid moment tensor data often shows well-defined orientation groups in scatterplots of fault plane normals and associated slip line vectors. These allow important geodynamic inferences, e.g., we can show that ductile faults control the geometry of oceanic transforms, and that normal fault earthquakes on spreading ridges are usually skewed with respect to adjacent transform faults. To explain this asymmetry requires finite rock strength, but it also means that it is not brittle failure that controls the orientation of oceanic transforms. This asymmetry also requires formation of tilt block geometries reminiscent of Basin-and-Range-style continental extension, systematic offset of earthquake hypocentres from the spreading ridge, and a general complexity in magma-fault interactions that is far beyond what might be expected if ocean-floor spreading is the result of dilating tension-mode fractures in dyke swarms. The role of ductile faulting should be given special mention because mostly it is argued that brittle faults are responsible for earthquakes. Yet many other examples of ductile faults in operation can be inferred, e.g., ductile faults associated with slab drop-off, where slab boudinage leads to extensional ductile faults and seismic activity driven by the pulling away of a relict slab, e.g., beneath the Hindu Kush. Another example might be found by close examination of the tectonic significance of the lowermost of the double (or paired) seismic zones such as can be seen in cross-sections of the subducting slab beneath Japan. The lowermost of the paired seismic zones may mark the locus of aseismic ductile shears or detachments formed by slumping of gigantic sheets of rock attempting to slide down the face of actively subducting slabs. Seismogenic activity may be driven by ductile faulting (again related to boudinage) of the relatively strong sheet of the subducting slab overlying this movement zone. The role of ductile faulting has been undervalued in earthquake generation, and this data suggests revision of seismotectonic doctrines may be necessary.

  12. 3D printed PLA-based scaffolds

    PubMed Central

    Serra, Tiziano; Mateos-Timoneda, Miguel A; Planell, Josep A; Navarro, Melba

    2013-01-01

    Rapid prototyping (RP), also known as additive manufacturing (AM), has been well received and adopted in the biomedical field. The capacity of this family of techniques to fabricate customized 3D structures with complex geometries and excellent reproducibility has revolutionized implantology and regenerative medicine. In particular, nozzle-based systems allow the fabrication of high-resolution polylactic acid (PLA) structures that are of interest in regenerative medicine. These 3D structures find interesting applications in the regenerative medicine field where promising applications including biodegradable templates for tissue regeneration purposes, 3D in vitro platforms for studying cell response to different scaffolds conditions and for drug screening are considered among others. Scaffolds functionality depends not only on the fabrication technique, but also on the material used to build the 3D structure, the geometry and inner architecture of the structure, and the final surface properties. All being crucial parameters affecting scaffolds success. This Commentary emphasizes the importance of these parameters in scaffolds’ fabrication and also draws the attention toward the versatility of these PLA scaffolds as a potential tool in regenerative medicine and other medical fields. PMID:23959206

  13. 3D Computer Vision and Video Computing 3D Vision3D Vision

    E-print Network

    Zhu, Zhigang

    1 3D Computer Vision and Video Computing 3D Vision3D Vision CSc I6716 Spring 2011 Topic 3 of Part II Stereo Vision p g Zhigang Zhu, City College of New York zhu@cs.ccny.cuny.edu 3D Computer Vision and Video Computing Stereo VisionStereo Vision Problem Infer 3D structure of a scene from two or more images

  14. 3D Computer Vision and Video Computing 3D Vision3D Vision

    E-print Network

    Zhu, Zhigang

    1 3D Computer Vision and Video Computing 3D Vision3D Vision CSc I6716 Fall 2010 Topic 3 of Part II Stereo Vision Zhigang Zhu, City College of New York zhu@cs.ccny.cuny.edu 3D Computer Vision and Video Computing Stereo VisionStereo Vision Problem Infer 3D structure of a scene from two or more images taken

  15. Potential for larger earthquakes in the East San Francisco Bay Area due to the direct connection between the Hayward and Calaveras Faults

    NASA Astrophysics Data System (ADS)

    Chaussard, E.; Bürgmann, R.; Fattahi, H.; Nadeau, R. M.; Taira, T.; Johnson, C. W.; Johanson, I.

    2015-04-01

    The Hayward and Calaveras Faults, two strike-slip faults of the San Andreas System located in the East San Francisco Bay Area, are commonly considered independent structures for seismic hazard assessment. We use Interferometric Synthetic Aperture RADAR to show that surface creep on the Hayward Fault continues 15 km farther south than previously known, revealing new potential for rupture and damage south of Fremont. The extended trace of the Hayward Fault, also illuminated by shallow repeating micro-earthquakes, documents a surface connection with the Calaveras Fault. At depths greater than 3-5 km, repeating micro-earthquakes located 10 km north of the surface connection highlight the 3-D wedge geometry of the junction. Our new model of the Hayward and Calaveras Faults argues that they should be treated as a single system with potential for earthquake ruptures generating events with magnitudes greater than 7, posing a higher seismic hazard to the East San Francisco Bay Area than previously considered.

  16. GEN3D Ver. 1.37

    Energy Science and Technology Software Center (ESTSC)

    2012-01-04

    GEN3D is a three-dimensional mesh generation program. The three-dimensional mesh is generated by mapping a two-dimensional mesh into threedimensions according to one of four types of transformations: translating, rotating, mapping onto a spherical surface, and mapping onto a cylindrical surface. The generated three-dimensional mesh can then be reoriented by offsetting, reflecting about an axis, and revolving about an axis. GEN3D can be used to mesh geometries that are axisymmetric or planar, but, due to three-dimensionalmore »loading or boundary conditions, require a three-dimensional finite element mesh and analysis. More importantly, it can be used to mesh complex three-dimensional geometries composed of several sections when the sections can be defined in terms of transformations of two dimensional geometries. The code GJOIN is then used to join the separate sections into a single body. GEN3D reads and writes twodimensional and threedimensional mesh databases in the GENESIS database format; therefore, it is compatible with the preprocessing, postprocessing, and analysis codes used by the Engineering Analysis Department at Sandia National Laboratories, Albuquerque, NM.« less

  17. Trishear for curved faults

    NASA Astrophysics Data System (ADS)

    Brandenburg, J. P.

    2013-08-01

    Fault-propagation folds form an important trapping element in both onshore and offshore fold-thrust belts, and as such benefit from reliable interpretation. Building an accurate geologic interpretation of such structures requires palinspastic restorations, which are made more challenging by the interplay between folding and faulting. Trishear (Erslev, 1991; Allmendinger, 1998) is a useful tool to unravel this relationship kinematically, but is limited by a restriction to planar fault geometries, or at least planar fault segments. Here, new methods are presented for trishear along continuously curved reverse faults defining a flat-ramp transition. In these methods, rotation of the hanging wall above a curved fault is coupled to translation along a horizontal detachment. Including hanging wall rotation allows for investigation of structures with progressive backlimb rotation. Application of the new algorithms are shown for two fault-propagation fold structures: the Turner Valley Anticline in Southwestern Alberta, and the Alpha Structure in the Niger Delta.

  18. PLOT3D Export Tool for Tecplot

    NASA Technical Reports Server (NTRS)

    Alter, Stephen

    2010-01-01

    The PLOT3D export tool for Tecplot solves the problem of modified data being impossible to output for use by another computational science solver. The PLOT3D Exporter add-on enables the use of the most commonly available visualization tools to engineers for output of a standard format. The exportation of PLOT3D data from Tecplot has far reaching effects because it allows for grid and solution manipulation within a graphical user interface (GUI) that is easily customized with macro language-based and user-developed GUIs. The add-on also enables the use of Tecplot as an interpolation tool for solution conversion between different grids of different types. This one add-on enhances the functionality of Tecplot so significantly, it offers the ability to incorporate Tecplot into a general suite of tools for computational science applications as a 3D graphics engine for visualization of all data. Within the PLOT3D Export Add-on are several functions that enhance the operations and effectiveness of the add-on. Unlike Tecplot output functions, the PLOT3D Export Add-on enables the use of the zone selection dialog in Tecplot to choose which zones are to be written by offering three distinct options - output of active, inactive, or all zones (grid blocks). As the user modifies the zones to output with the zone selection dialog, the zones to be written are similarly updated. This enables the use of Tecplot to create multiple configurations of a geometry being analyzed. For example, if an aircraft is loaded with multiple deflections of flaps, by activating and deactivating different zones for a specific flap setting, new specific configurations of that aircraft can be easily generated by only writing out specific zones. Thus, if ten flap settings are loaded into Tecplot, the PLOT3D Export software can output ten different configurations, one for each flap setting.

  19. A 3D geological and geomechanical model of the 1963 Vajont landslide

    NASA Astrophysics Data System (ADS)

    Bistacchi, Andrea; Massironi, Matteo; Francese, Roberto; Giorgi, Massimo; Chistolini, Filippo; Battista Crosta, Giovanni; Castellanza, Riccardo; Frattini, Paolo; Agliardi, Federico; Frigerio, Gabriele

    2014-05-01

    The Vajont rockslide has been the object of several studies because of its catastrophic consequences and particular evolution. Several qualitative or quantitative models have been presented in the last 50 years, but a complete explanation of all relevant geological and mechanical processes remains elusive. In order to better understand the mechanics and dynamics of the 1963 event, we have reconstructed the first 3D geological model of the rockslide, which allowed us to accurately investigate the rockslide structure and kinematics. The input data for the model consisted in: pre- and post-rockslide geological maps, pre- and post-rockslide orthophotos, pre- and post-rockslide digital elevation models, structural data, boreholes, and geophysical data (2D and 3D seismics and resistivity). All these data have been integrated in a 3D geological model implemented in Gocad®, using the implicit surface modelling method. Results of the 3D geological model include the depth and geometry of the sliding surface, the volume of the two lobes of the rockslide accumulation, kinematics of the rockslide in terms of the vector field of finite displacement, and high quality meshes useful for mechanical and hydrogeological simulations. The latter can include information about the stratigraphy and internal structure of the rock masses and allow tracing the displacement of different material points in the rockslide from the pre-1963-failure to the post-rockslide state. As a general geological conclusion, we may say that the 3D model allowed us to recognize very effectively a sliding surface, whose non-planar geometry is affected by the interference pattern of two regional-scale fold systems. The rockslide is partitioned into two distinct and internally continuous rock masses with a distinct kinematics, which were characterised by a very limited internal deformation during the slide. The continuity of these two large blocks points to a very localized deformation, occurring along a thin, continuous and weak cataclastic horizon. The chosen modelling strategy, based on both traditional "explicit" and implicit techniques, was found to be very effective for reconstructing complex folded and faulted geological structures, and could be applied also to other geological environments. Finally 3D FEM analyses using the code MidasGTS have been performed adopting the 3D geological model. A c-phi reduction procedure was employed along the pre-defined failure surface until the onset of the landslide occurred. The initiation of the rock mass movements is properly described by considering the evolution of plastic shear strain in the failure surface. The stress, strain and displacement fields of the rock mass were analysed in detail and compared with the monitored data.

  20. Modeling of Mantle Convection in 3D Subduction Zones

    NASA Astrophysics Data System (ADS)

    Bengtson, A. K.; van Keken, P. E.; Lin, S.; Kneller, E. A.

    2010-12-01

    The influence of 3D subduction zone geometries on mantle convection patterns is not well characterized. Subducting plates with complex 3D geometries often exhibit seismological signatures that cannot be explained by 2D flow patterns [Hoernle et al. Nature 2008/2009; Long and Silver Science 2008; Kneller et al. Nature 2007]. We use finite element methods to study the lateral transport and thermal structure in 3D subduction zones and their evolution over time. Realistic 3D geometries were created from seismological observations for both the Marianas and Central America, building upon the work of Kneller et al. [Nature 2007; Geochem. Geophys. Geosyst. 2008]. Highly refined meshes were created using spherical geometry on a Cartesian mesh, and slab motion was prescribed in a kinematic manner. The finite element code Sepran was used to solve the Stokes and heat equations using diffusion creep laws for viscosity. We present the velocities, temperatures, and pressures in the mantle wedge for the Marianas and Central America regions. Comparisons are made between 2D and 3D flow patterns to test the dependence of flow on 3D geometries, in addition to dependence of flow on plate direction. Resulting thermal and lateral structures are important for understanding mantle and slab mineralogy and seismic signatures. We find the lateral transport is particularly important in regions of strong obliquity and trench curvature.

  1. 3D modeling with silhouettes

    E-print Network

    Rivers, Alec (Alec Rothmyer)

    2010-01-01

    With the increasing power of computers and the spread of dedicated graphics hardware, 3D content has become ubiquitous in every field, from medicine to video games. However, designing 3D models remains a time-consuming and ...

  2. INCORPORATING DYNAMIC 3D SIMULATION INTO PRA

    SciTech Connect

    Steven R Prescott; Curtis Smith

    2011-07-01

    Through continued advancement in computational resources, development that was previously done by trial and error production is now performed through computer simulation. These virtual physical representations have the potential to provide accurate and valid modeling results and are being used in many different technical fields. Risk assessment now has the opportunity to use 3D simulation to improve analysis results and insights, especially for external event analysis. By using simulations, the modeler only has to determine the likelihood of an event without having to also predict the results of that event. The 3D simulation automatically determines not only the outcome of the event, but when those failures occur. How can we effectively incorporate 3D simulation into traditional PRA? Most PRA plant modeling is made up of components with different failure modes, probabilities, and rates. Typically, these components are grouped into various systems and then are modeled together (in different combinations) as a “system” with logic structures to form fault trees. Applicable fault trees are combined through scenarios, typically represented by event tree models. Though this method gives us failure results for a given model, it has limitations when it comes to time-based dependencies or dependencies that are coupled to physical processes which may themselves be space- or time-dependent. Since, failures from a 3D simulation are naturally time related, they should be used in that manner. In our simulation approach, traditional static models are converted into an equivalent state diagram representation with start states, probabilistic driven movements between states and terminal states. As the state model is run repeatedly, it converges to the same results as the PRA model in cases where time-related factors are not important. In cases where timing considerations are important (e.g., when events are dependent upon each other), then the simulation approach will typically provide superior results and insights. We also couple the state model with the dynamic 3D simulation analysis representing events (such as flooding) to determine which (if any) components fail. Not only does the simulation take into account any failed items from the state model, but any failures caused by the simulation are incorporated back into the state model and factored into the overall results. Using this method we incorporate accurate 3D simulation results, eliminate static-based PRA issues, and have time ordered failure information.

  3. Simulating Large-Scale Earthquake Dynamic Rupture Scenarios On Natural Fault Zones Using the ADER-DG Method

    NASA Astrophysics Data System (ADS)

    Gabriel, Alice; Pelties, Christian

    2014-05-01

    In this presentation we will demonstrate the benefits of using modern numerical methods to support physic-based ground motion modeling and research. For this purpose, we utilize SeisSol an arbitrary high-order derivative Discontinuous Galerkin (ADER-DG) scheme to solve the spontaneous rupture problem with high-order accuracy in space and time using three-dimensional unstructured tetrahedral meshes. We recently verified the method in various advanced test cases of the 'SCEC/USGS Dynamic Earthquake Rupture Code Verification Exercise' benchmark suite, including branching and dipping fault systems, heterogeneous background stresses, bi-material faults and rate-and-state friction constitutive formulations. Now, we study the dynamic rupture process using 3D meshes of fault systems constructed from geological and geophysical constraints, such as high-resolution topography, 3D velocity models and fault geometries. Our starting point is a large scale earthquake dynamic rupture scenario based on the 1994 Northridge blind thrust event in Southern California. Starting from this well documented and extensively studied event, we intend to understand the ground-motion, including the relevant high frequency content, generated from complex fault systems and its variation arising from various physical constraints. For example, our results imply that the Northridge fault geometry favors a pulse-like rupture behavior.

  4. Conclusions Adding 3D sound

    E-print Network

    · Conclusions Adding 3D sound did enhance the self-motion illusion, even though the visual illusion alone was already quite compelling We conclude that adding spatialized 3D-sound that moves concordantly the 3D-sound (9.9s vection onset time, which is quite low for a FOV of just 54°x40.5°). Merely adding

  5. Distributed deformation and block rotation in 3D

    NASA Technical Reports Server (NTRS)

    Scotti, Oona; Nur, Amos; Estevez, Raul

    1990-01-01

    The authors address how block rotation and complex distributed deformation in the Earth's shallow crust may be explained within a stationary regional stress field. Distributed deformation is characterized by domains of sub-parallel fault-bounded blocks. In response to the contemporaneous activity of neighboring domains some domains rotate, as suggested by both structural and paleomagnetic evidence. Rotations within domains are achieved through the contemporaneous slip and rotation of the faults and of the blocks they bound. Thus, in regions of distributed deformation, faults must remain active in spite of their poor orientation in the stress field. The authors developed a model that tracks the orientation of blocks and their bounding faults during rotation in a 3D stress field. In the model, the effective stress magnitudes of the principal stresses (sigma sub 1, sigma sub 2, and sigma sub 3) are controlled by the orientation of fault sets in each domain. Therefore, adjacent fault sets with differing orientations may be active and may display differing faulting styles, and a given set of faults may change its style of motion as it rotates within a stationary stress regime. The style of faulting predicted by the model depends on a dimensionless parameter phi = (sigma sub 2 - sigma sub 3)/(sigma sub 1 - sigma sub 3). Thus, the authors present a model for complex distributed deformation and complex offset history requiring neither geographical nor temporal changes in the stress regime. They apply the model to the Western Transverse Range domain of southern California. There, it is mechanically feasible for blocks and faults to have experienced up to 75 degrees of clockwise rotation in a phi = 0.1 strike-slip stress regime. The results of the model suggest that this domain may first have accommodated deformation along preexisting NNE-SSW faults, reactivated as normal faults. After rotation, these same faults became strike-slip in nature.

  6. 'Diamond' in 3-D

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 3-D, microscopic imager mosaic of a target area on a rock called 'Diamond Jenness' was taken after NASA's Mars Exploration Rover Opportunity ground into the surface with its rock abrasion tool for a second time.

    Opportunity has bored nearly a dozen holes into the inner walls of 'Endurance Crater.' On sols 177 and 178 (July 23 and July 24, 2004), the rover worked double-duty on Diamond Jenness. Surface debris and the bumpy shape of the rock resulted in a shallow and irregular hole, only about 2 millimeters (0.08 inch) deep. The final depth was not enough to remove all the bumps and leave a neat hole with a smooth floor. This extremely shallow depression was then examined by the rover's alpha particle X-ray spectrometer.

    On Sol 178, Opportunity's 'robotic rodent' dined on Diamond Jenness once again, grinding almost an additional 5 millimeters (about 0.2 inch). The rover then applied its Moessbauer spectrometer to the deepened hole. This double dose of Diamond Jenness enabled the science team to examine the rock at varying layers. Results from those grindings are currently being analyzed.

    The image mosaic is about 6 centimeters (2.4 inches) across.

  7. Prominent rocks - 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Many prominent rocks near the Sagan Memorial Station are featured in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. Wedge is at lower left; Shark, Half-Dome, and Pumpkin are at center. Flat Top, about four inches high, is at lower right. The horizon in the distance is one to two kilometers away.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  8. 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 this basin in 1999 suitable for future 3D FWI. We build a 3D model of the sub-surface based on an existing velocity model that was used to migrate these data (Tsuji et al. 2000, JGR). We then add a low P-wave velocity layer along the décollement, which is supported by ODP core data but does not feature in the current seismic velocity model, to test if it could be recovered using 3D FWI. We use the same acquisition parameters as in the 1999 seismic survey (including a 6 km long streamer) to generate a fully-elastic synthetic seismic dataset, added noise and inverted the windowed transmitted arrivals only. We also ran a suite of resolution tests across the model. The results show that 3D FWI of conventionally collected 3D seismic data across the Muroto Basin would be capable of resolving variations in P-wave velocity along the décollement of the order of half the seismic wavelength at the plate boundary. This is a significant improvement on conventional travel-time tomography which resolves to the Fresnel width. In this presentation we will also postulate on the optimal 3D FWI experiment design for the next generation of 3D seismic surveys across subduction margins as a guide for those embarking on new data collection.

  9. Local Diagnosis of Reconnection in 3D

    NASA Astrophysics Data System (ADS)

    Scudder, J. D.; Karimabadi, H.; Daughton, W. S.; Roytershteyn, V.

    2014-12-01

    We demonstrate (I,II) an approach to find reconnection sites in 3D where there is no flux function for guidance, and where local observational signatures for the ``violation of frozen flux'' are under developed, if not non-existent. We use 2D and 3D PIC simulations of asymmetric guide field reconnection to test our observational hierarchy of single spacecraft kinetic diagnostics - all possible with present state of the art instrumentation. The proliferation of turbulent, electron inertial scale layers in the realistic 3D case demonstrates that electron demagnetization, while necessary, is not sufficient to identify reconnection sites. An excellent local, observable, single spacecraft proxy is demonstrated for the size of the theoretical frozen flux violation. Since even frozen flux violations need not imply reconnection is at hand, a new calibrated dimensionless method is used to determine the importance of such violations. This measure is available in 2D and 3D to help differentiate reconnection layers from weaker frozen flux violating layers. We discuss the possibility that this technique can be implemented on MMS. A technique to highlight flow geometries conducive to reconnection in 3D simulations is also suggested, that may also be implementable with the MMS flotilla. We use local analysis with multiple necessary, but theoretically independent electron kinetic conditions to help reduce the probability of misidentification of any given layer as a reconnection site. Since these local conditions are all necessary for the site, but none is known to be sufficient, the multiple tests help to greatly reduce false positive identifications. The selectivity of the results of this approach using PIC simulations of 3D asymmetric guide field reconnection will be shown using varying numbers of simultaneous conditions. Scudder, J.D., H. Karimabadi, W. Daughton and V. Roytershteyn I, II, submitted Phys. Plasma., 2014

  10. Parallel computing with M3D

    NASA Astrophysics Data System (ADS)

    Tang, X. Z.; Park, W.; Strauss, H. R.

    1998-11-01

    We consider the parallel computing aspect of the M3D project(W. Park et al., Plasma Phys. and Contr. Nucl. Fusion Research) (IAEA, Vienna, 1997), Vol. 2, p.411.. The short term priority is to adapt existing codes to parallel computing platforms with minimal modifications to the algorithms. The objective is to satisfy the immedeiate computational needs in current research. The long term goals will be developing portable and scalable parallel codes that efficiently utilize the MPP platforms. The parallelization strategy would then play a larger role in determining the algorithm design. The unstructured-mesh finite element MH3D++(H.R. Strauss and W. Park, Phys. Plasmas 5) 2676 (1998). is being adapted to a shared-memory SGI Orgin 2000. The MH3D++ code has been used for following pellet injections and disruptions in tokamaks, and has now been adapted for stellarators. The parallel version of the code uses a 3D mesh in configuration space, rather than the previous toroidal spectral representation. Our approach is to take advantage of the inherent parallelism in MH3D++, which decomposes a toroidal geometry into a set of poloidal planes. The most CPU intensive part of MH3D++ uses conjugate gradient methods to solve elliptic problems at each time step. These solves are local to each poloidal plane and can be done in parallel. The coupling of poloidal planes is spatially local and explicit, and is less important as far as parallelism is concerned. Examples and performance data will be presented.

  11. Study of the Potential Earthquake Risk in the Western United States by the LURR Method Based on the Seismic Catalogue, Fault Geometry and Focal Mechanisms

    NASA Astrophysics Data System (ADS)

    Zhang, Yongxian; Yikilmaz, M. Burak; Rundle, John B.; Yin, Xiangchu; Liu, Yue; Zhang, Langping; Wang, Zijin

    2015-08-01

    Based on the load/unload response ratio (LURR) theory, spatial and temporal variation of Y/ Y c (value of LURR/critical value of LURR under 90 % confidence) in the western United States and its adjacent area (31°-44°N, -128° to -112°E) during the period from 1980 to 2011 was studied. The selected study area was zoned into 20 sub-regions, in each of which the fault geometry and the focal mechanisms were very similar such that the stress fields were almost uniform. The loading and unloading periods were determined by calculating perturbations in the Coulomb failure stress in each sub-regions induced by earth tides. Earthquakes occurring in these sub-regions were identified as a loading or unloading type, and the response rate was chosen as the Benioff strain that can be calculated from earthquake magnitude M. With a time window of 1 year, a time moving step of 1 month, a space window of a circle region with a radius of 100 km, and a space moving step of 0.5° latitudinally and longitudinally, snapshots of the evolution of Y/ Y c were generated. Scanning results show that obvious Y/ Y c anomalies can be detected near the epicenter of all big earthquakes larger than M6.5 in regions with reasonable seismic monitoring abilities. They also show Y/ Y c anomalies occurred several years prior to the big earthquakes and the lasting time of the anomaly is from one year to several years. For some LURR anomalous regions, however, no earthquakes occurred. According to the characteristics of LURR anomalies, two regions with a high risk of big earthquakes were detected. One is between the northern region of the Bay Area and the Mendocino triple junction (38°-40°N, -124° to -122°E) and the other is between Lake Tahoe and Mono Lake (37.5°-39.5°N, -120° to -118°E) along the border of California and Nevada.

  12. Investigation of active faulting at the Emigrant Peak fault in Nevada using shallow seismic reflection and ground penetrating radar

    E-print Network

    Christie, Michael Wayne

    2007-12-18

    and 4-40 m respectively. Both the SSR and GPR data revealed structural geometries dominated by NW-dipping normal faulting and corresponding antithetic faults with identifiable offsets. Near the main fault strand, alluvial fan strata dip consistently...

  13. A 2D driven 3D vessel segmentation algorithm for 3D digital subtraction angiography data

    NASA Astrophysics Data System (ADS)

    Spiegel, M.; Redel, T.; Struffert, T.; Hornegger, J.; Doerfler, A.

    2011-10-01

    Cerebrovascular disease is among the leading causes of death in western industrial nations. 3D rotational angiography delivers indispensable information on vessel morphology and pathology. Physicians make use of this to analyze vessel geometry in detail, i.e. vessel diameters, location and size of aneurysms, to come up with a clinical decision. 3D segmentation is a crucial step in this pipeline. Although a lot of different methods are available nowadays, all of them lack a method to validate the results for the individual patient. Therefore, we propose a novel 2D digital subtraction angiography (DSA)-driven 3D vessel segmentation and validation framework. 2D DSA projections are clinically considered as gold standard when it comes to measurements of vessel diameter or the neck size of aneurysms. An ellipsoid vessel model is applied to deliver the initial 3D segmentation. To assess the accuracy of the 3D vessel segmentation, its forward projections are iteratively overlaid with the corresponding 2D DSA projections. Local vessel discrepancies are modeled by a global 2D/3D optimization function to adjust the 3D vessel segmentation toward the 2D vessel contours. Our framework has been evaluated on phantom data as well as on ten patient datasets. Three 2D DSA projections from varying viewing angles have been used for each dataset. The novel 2D driven 3D vessel segmentation approach shows superior results against state-of-the-art segmentations like region growing, i.e. an improvement of 7.2% points in precision and 5.8% points for the Dice coefficient. This method opens up future clinical applications requiring the greatest vessel accuracy, e.g. computational fluid dynamic modeling.

  14. 3-D geomechanical modelling of a gas reservoir in the North German Basin: workflow for model building and calibration

    NASA Astrophysics Data System (ADS)

    Fischer, K.; Henk, A.

    2013-06-01

    The optimal use of conventional and unconventional hydrocarbon reservoirs depends, amongst others, on the local tectonic stress field. For example, wellbore stability, orientation of hydraulically induced fractures and - especially in fractured reservoirs - permeability anisotropies are controlled by the recent in situ stresses. Faults and lithological changes can lead to stress perturbations and produce local stresses that can significantly deviate from the regional stress field. Geomechanical reservoir models aim for a robust, ideally "pre-drilling" prediction of the local variations in stress magnitude and orientation. This requires a~numerical modelling approach that is capable to incorporate the specific geometry and mechanical properties of the subsurface reservoir. The workflow presented in this paper can be used to build 3-D geomechanical models based on the Finite Element Method (FEM) and ranging from field-scale models to smaller, detailed submodels of individual fault blocks. The approach is successfully applied to an intensively faulted gas reservoir in the North German Basin. The in situ stresses predicted by the geomechanical FE model were calibrated against stress data actually observed, e.g. borehole breakouts and extended leak-off tests. Such a validated model can provide insights into the stress perturbations in the inter-well space and undrilled parts of the reservoir. In addition, the tendency of the existing fault network to slip or dilate in the present-day stress regime can be addressed.

  15. 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.

  16. Immersive 3D geovisualisation in higher education

    NASA Astrophysics Data System (ADS)

    Philips, Andrea; Walz, Ariane; Bergner, Andreas; Graeff, Thomas; Heistermann, Maik; Kienzler, Sarah; Korup, Oliver; Lipp, Torsten; Schwanghart, Wolfgang; Zeilinger, Gerold

    2014-05-01

    Through geovisualisation we explore spatial data, we analyse it towards a specific questions, we synthesise results, and we present and communicate them to a specific audience (MacEachren & Kraak 1997). After centuries of paper maps, the means to represent and visualise our physical environment and its abstract qualities have changed dramatically since the 1990s - and accordingly the methods how to use geovisualisation in teaching. Whereas some people might still consider the traditional classroom as ideal setting for teaching and learning geographic relationships and its mapping, we used a 3D CAVE (computer-animated virtual environment) as environment for a problem-oriented learning project called "GEOSimulator". Focussing on this project, we empirically investigated, if such a technological advance like the CAVE make 3D visualisation, including 3D geovisualisation, not only an important tool for businesses (Abulrub et al. 2012) and for the public (Wissen et al. 2008), but also for educational purposes, for which it had hardly been used yet. The 3D CAVE is a three-sided visualisation platform, that allows for immersive and stereoscopic visualisation of observed and simulated spatial data. We examined the benefits of immersive 3D visualisation for geographic research and education and synthesized three fundamental technology-based visual aspects: First, the conception and comprehension of space and location does not need to be generated, but is instantaneously and intuitively present through stereoscopy. Second, optical immersion into virtual reality strengthens this spatial perception which is in particular important for complex 3D geometries. And third, a significant benefit is interactivity, which is enhanced through immersion and allows for multi-discursive and dynamic data exploration and knowledge transfer. Based on our problem-oriented learning project, which concentrates on a case study on flood risk management at the Wilde Weisseritz in Germany, a river that significantly contributed to the hundred-year flooding in Dresden in 2002, we empirically evaluated the usefulness of this immersive 3D technology towards learning success. Results show that immersive 3D geovisualisation have educational and content-related advantages compared to 2D geovisualisations through the mentioned benefits. This innovative way of geovisualisation is thus not only entertaining and motivating for students, but can also be constructive for research studies by, for instance, facilitating the study of complex environments or decision-making processes.

  17. Scaled 3D modeling of poly-phase tectonic deformation: A new analogue material for basement rock, with controlled variable strength.

    NASA Astrophysics Data System (ADS)

    Nieuwland, D. A.; Koekoek, G.; van Mechelen, D.; Papo, M.

    2003-04-01

    A common process in tectonic faulting is that of poly-phase deformation. A majority of neo-tectonic structures is controlled by reactivated pre-existing faults in the underlying basement. A reliable interpretation of such neo-tectonic structures is only possible if the process of the poly-phase deformation can be described and understood in terms of the geomechanics. We have developed an analogue modelling approach to poly-phase deformation. The aim of the project was to construct analogue models with reliable scaling of strength, length, geometry and kinematics of poly-phase tectonic deformation in 3D. The natural process generally involves a faulted basement sequence of relatively strong rocks and a younger cover sequence of weaker rocks. The main problem here has always been to find a material to model the strong basement rocks. A good basement analogue needs to be strong enough to support fault reactivation without braking itself, however, it should brake when the stress conditions require. For example, compression perpendicular to a steep basement fault should break the basement. The weak cover can be modelled with dry sand, which is essentially cohesionless, but for the stronger basement a good analogue was not available (wooden blocks often used in analogue models are too strong). The orientation and geometry of faults and fault patterns is controlled by the internal friction angle (f) of the deformed rock. For the majority of brittle rocks f is of the order of 30o, for the sand that is used for analogue modelling f=32o. In order to model the basement rock a brittle material was needed that must be stronger that dry sand, strong enough to remain intact during fault reactivation, but weak enough to break when a fault is too steep to be reactivated in horizontal compression conditions. In the analogue modelling lab of the VU (TecLab) we have recently succeeded in forming such a basement material. The material can be made at any required strength to make reliably scaled poly-phase analogue models. Of a variety of sands the tensile strength has been measured under a range of confining pressures. Following measurements on dry sand, tensile strength has been added by wetting the sand with capillary water. The surface tension of the water provides the tensile strength of the sandpack. Controlled variation of the surface tension of the water by adding small amounts of alcohol results in a controlled tensile strength of the moist (basement) sand. Repeated measurements of the wet sand demonstrate the reproducibility of the technique. We present here an outline of the technique accompanied by examples of 3D experiments of scaled poly-phase tectonics.

  18. Supernova Remnant in 3-D

    NASA Technical Reports Server (NTRS)

    2009-01-01

    [figure removed for brevity, see original site] Click on the image for the movie

    For the first time, a multiwavelength three-dimensional reconstruction of a supernova remnant has been created. This stunning visualization of Cassiopeia A, or Cas A, the result of an explosion approximately 330 years ago, uses data from several telescopes: X-ray data from NASA's Chandra X-ray Observatory, infrared data from NASA's Spitzer Space Telescope and optical data from the National Optical Astronomy Observatory 4-meter telescope at Kitt Peak, Ariz., and the Michigan-Dartmouth-MIT 2.4-meter telescope, also at Kitt Peak. In this visualization, the green region is mostly iron observed in X-rays. The yellow region is a combination of argon and silicon seen in X-rays, optical, and infrared including jets of silicon plus outer debris seen in the optical. The red region is cold debris seen in the infrared. Finally, the blue reveals the outer blast wave, most prominently detected in X-rays.

    Most of the material shown in this visualization is debris from the explosion that has been heated by a shock moving inwards. The red material interior to the yellow/orange ring has not yet encountered the inward moving shock and so has not yet been heated. These unshocked debris were known to exist because they absorb background radio light, but they were only recently discovered in infrared emission with Spitzer. The blue region is composed of gas surrounding the explosion that was heated when it was struck by the outgoing blast wave, as clearly seen in Chandra images.

    To create this visualization, scientists took advantage of both a previously known phenomenon the Doppler effect and a new technology that bridges astronomy and medicine. When elements created inside a supernova, such as iron, silicon and argon, are heated they emit light at certain wavelengths. Material moving towards the observer will have shorter wavelengths and material moving away will have longer wavelengths. Since the amount of the wavelength shift is related to the speed of motion, one can determine how fast the debris are moving in either direction. Because Cas A is the result of an explosion, the stellar debris is expanding radially outwards from the explosion center. Using simple geometry, the scientists were able to construct a 3-D model using all of this information. A program called 3-D Slicer modified for astronomical use by the Astronomical Medicine Project at Harvard University in Cambridge, Mass. was used to display and manipulate the 3-D model. Commercial software was then used to create the 3-D fly-through.

    The blue filaments defining the blast wave were not mapped using the Doppler effect because they emit a different kind of light synchrotron radiation that does not emit light at discrete wavelengths, but rather in a broad continuum. The blue filaments are only a representation of the actual filaments observed at the blast wave.

    This visualization shows that there are two main components to this supernova remnant: a spherical component in the outer parts of the remnant and a flattened (disk-like) component in the inner region. The spherical component consists of the outer layer of the star that exploded, probably made of helium and carbon. These layers drove a spherical blast wave into the diffuse gas surrounding the star. The flattened component that astronomers were unable to map into 3-D prior to these Spitzer observations consists of the inner layers of the star. It is made from various heavier elements, not all shown in the visualization, such as oxygen, neon, silicon, sulphur, argon and iron.

    High-velocity plumes, or jets, of this material are shooting out from the explosion in the plane of the disk-like component mentioned above. Plumes of silicon appear in the northeast and southwest, while those of iron are seen in the southeast and north. These jets were already known and Doppler velocity measurements have been made for these structures, but their orientation and position with resp

  19. 2005-01-3557 Vehicle-borne Scanning for Detailed 3D Terrain Model

    E-print Network

    Koschan, Andreas

    ; and the laser range-based approach, where the 3D geometry is measured directly through laser range scanners2005-01-3557 Vehicle-borne Scanning for Detailed 3D Terrain Model Generation Brad Grinstead in a variety of tasks, but digitizing a large environment poses constraints on the design of a 3D scanning

  20. Reconnection experiments with 3D magnetic nulls

    NASA Astrophysics Data System (ADS)

    Vrublevskis, A.; Egedal, J.; Le, A.; Montag, P.

    2011-10-01

    Three-dimensional effects have been crucial in explaining experiments at the Versatile Toroidal Facility (VTF) even in nominal axisymmetric plasmas with a non-vanishing toroidal field. In general, depending on the topological and geometric structure of the magnetic field, a rich collection of magnetic reconnection scenarios is possible in three dimensions. The new adjustable set of coils in VTF allows exploring reconnection in 2D and 3D geometries including configurations with magnetic null points. We present results of a numerical and experimental investigation of magnetic field topologies attainable in VTF. This work was supported by NSF CAREER Award 0844620.

  1. 3D temperature model of south-western South America

    NASA Astrophysics Data System (ADS)

    Tassara, Andres; Morales, Daniel

    2013-04-01

    Temperature (T) and pressure (P) control the thermodynamics and physico-chemical behavior of Earth materials. PT conditions regulates by one side the type and relative amount of minerals forming a rock for a given chemical composition, and by the other also the physical properties of these minerals. Therefore, knowledge about the internal thermal structure of the lithosphere is fundamental in order to predict spatial variations on primary rocks properties, which further regulate the geodynamic behavior of plates, their thermomechanic configuration and tectono-magmatic evolution. Due to this fundamental role, increasing efforts are being dedicated to generate reliable models of temperature distribution inside the lithosphere for different tectonic regions of the planet. Such models should include a sufficiently large number of good-quality and well-distributed surface heat flow measurements that can be used to invert geothermal gradients. However, most of the world, including the south-western margin of South America, lack such measurements and other indirect approaches must be applied in order to derive the thermal structure. Here we present a regional-scale thermal model for the Andean margin between 18°S and 45°S. This model is based on an exisiting 3D geological model for this region that unifies a large geophysical database (seismicity, 2D and 3D seismic velocity models, receiver functions, land- and satellite-derived gravity) into a lithospheric-scale representation of the geometry for main geotectonic discontinuities like the subducted slab upper surface, the lithosphere-astenosphere boundary (LAB), continental crust-mantle boundary (Moho) and intracurstal discontinuity (ICD). From a regularly gridded interpolation of these geometries at a spatial resolution of 15 km, we computed at each grid node a 1D geothermal gradient that we then merged to create the 3D thermal structure. We assume that the lithosphere geotherm is defined by heat conduction with radioactive heat production regulated by the compositional structure of crust and mantle, and impose that the temperature at the base of the continental lithosphere is dictated by a particular condition. For the region east to the intersection of LAB with the subducted slab, we assume that the LAB correspond to the intersection of a adiabatic astenosphere with the conductive lithosphere and take its temperature as defined by the potential temperature of the adiabat at the surface and a constant adiabatic gradient. The thermal structure at the forearc region to the west of LAB-Slab intersection is defined by the temperature at the plate interface, which we compute considering the heat flow coming from the subducted plate, fault friction and a reduction factor that depends on convergence velocity and subduction geometry. We have tested different combinations of the many parameters involved in defining the model and compared the resulting values of surface heat flow against a compiltation of measurements in order to evaluate the performance of the models. Our preferred model fits most of the data and we will show here some examples of the usefulness of the model for estimating the geothermal energy potential of the region and the understanding of the thermomechanic behavior of the lithosphere in relation with active magmatism and tectonics.

  2. 3D Model of the San Emidio Geothermal Area

    DOE Data Explorer

    James E. Faulds

    2013-12-31

    The San Emidio geothermal system is characterized by a left-step in a west-dipping normal fault system that bounds the western side of the Lake Range. The 3D geologic model consists of 5 geologic units and 55 faults. Overlying Jurrassic-Triassic metasedimentary basement is a ~500 m-1000 m thick section of the Miocene lower Pyramid sequence, pre- syn-extensional Quaternary sedimentary rocks and post-extensional Quaternary rocks. 15-30º eastward dip of the stratigraphy is controlled by the predominant west-dipping fault set. Both geothermal production and injection are concentrated north of the step over in an area of closely spaced west dipping normal faults.

  3. Challenges and perspectives in the geological study of active faults.

    NASA Astrophysics Data System (ADS)

    Rizza, M.

    2011-12-01

    Identification of active faults is important for understanding regional seismicity and seismic hazard. A large part of the world's population lives in areas where destructive earthquakes or tsunamis were recorded in the past. Most of the difficulties in estimating seismic hazard and anticipating earthquakes are due to a lack of knowledge about the location of active faults and their seismic history. Even where active faults are known the characteristics of past earthquakes and the seismic cycle are uncertain and subject to discussion. Investigations carried out on active faults during the past decade, however, have provided new high-quality data and powerful tools to better understand crustal deformation and the recurrence of earthquakes. In morphotectonic studies, the ever-improving resolution of satellites images allows geologists to identify with more certainty the traces of active faults and even earthquake surface ruptures of the past. The advantage of satellite imagery for identifying neotectonic features is it gives access to large areas, sometimes difficult to reach in the field and provides synoptic views. Using the potential of high-resolution imagery and digital elevation models, geologists can produce detailed 3D reconstructions of fault morphology and geometry, including the kinematics of repeated slip. The development of new dating techniques, coupled with paleoseismology and quantitative geomorphology, now allows bracketing the occurrence of paleoearthquakes back to several thousand years, as well as analyzing long time sequences of events. Despite such wealth of new data, however, the work remaining to do is huge. Earthquake forecast (location, timing, magnitude) remains an unsolved problem for the earthquake community at large (seismologists, geodesists, paleoseismologists and modelers). The most important challenges in the next decade will be to increase the efficiency of neotectonic studies to create more complete active fault databases and better model fault behavior. This is vital if we want to improve seismic hazard estimates and construction codes for a better protection of buildings and people living in earthquake zones.

  4. Subsidence, Compaction and Gravity-Sliding: Understanding Geodetic Strain Data Across Basin-Bounding Faults in Southern California

    NASA Astrophysics Data System (ADS)

    Nicholson, C.; Kamerling, M. J.; Sorlien, C. C.; Brune, J. N.

    2001-12-01

    High rates of geodetic shortening occur across the Los Angeles and Ventura basins. This deformation is inferred to represent a significant seismic hazard, and is presumed to be largely accommodated by active hanging-wall faulting, folding and tectonic uplift. In southern California, however, these deep subsiding basins are often bounded by oblique reverse faults that thrust early-Cenozoic and older rocks over young unconsolidated sediments. This suggests that footwall deformation, subsidence and compaction may play an important role in producing the apparent high strain rates. Even in the absence of active shortening, sediment compaction alone can produce surficial motions that mimic deep fault slip or elastic strain accumulation. Differential subsidence and compaction of footwall sediments relative to hanging-wall basement rocks can lead to increased vertical separation and fault rotation about horizontal axes. Such effects would contribute to net horizontal and vertical motions in both geologic and geodetic data. More importantly, subsidence and compaction can increase the potential for gravity-sliding towards the basin and the development of significant non-planar 3D fault geometry. A prime example occurs along the San Cayetano fault. Structure maps and cross sections derived from industry well data reveal a fault geometry reminiscent of thrust nappes in the western Alps. At shallow levels, a thin-skinned thrust sheet with low dip extends out in front of the deep, steeply-dipping fault segment by over 4 km, is nearly 2 km thick, and occupies over 60 cubic km. This geometry is strongly indicative of gravity-driven failure resulting from basinward tilt. Failure of this mega-slide off the hanging-wall block most likely occurred within the Rincon Formation, a ~400-m thick ductile shale sequence that often accommodates detachment slip. Slide reactivation was likely augmented by overpressured fluids trapped below the base of the slide. The thrust-nappe geometry of the San Cayetano fault has significant implications for how it and other basin-bounding faults may accommodate slip. If fault geometry is the result of an ancient gravity slide, the slide can be reactivated independently and/or aseismically. Observations of near-surface slip or large slip events at the toe of the slide may not be indicative of tectonic slip or large earthquakes at depth on the fault. Thus, in addition to the large contrast in elastic moduli, the observed high strain rates across basin-bounding faults may be the result of sedimentary, tectonic, and gravity-driven processes that all need to be thoroughly evaluated.

  5. Market study: 3-D eyetracker

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A market study of a proposed version of a 3-D eyetracker for initial use at NASA's Ames Research Center was made. The commercialization potential of a simplified, less expensive 3-D eyetracker was ascertained. Primary focus on present and potential users of eyetrackers, as well as present and potential manufacturers has provided an effective means of analyzing the prospects for commercialization.

  6. Modular 3-D Transport model

    EPA Science Inventory

    MT3D was first developed by Chunmiao Zheng in 1990 at S.S. Papadopulos & Associates, Inc. with partial support from the U.S. Environmental Protection Agency (USEPA). Starting in 1990, MT3D was released as a pubic domain code from the USEPA. Commercial versions with enhanced capab...

  7. 3D World Building System

    ScienceCinema

    None

    2014-02-26

    This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.

  8. 3D World Building System

    SciTech Connect

    2013-10-30

    This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.

  9. LLNL-Earth3D

    Energy Science and Technology Software Center (ESTSC)

    2013-10-01

    Earth3D is a computer code designed to allow fast calculation of seismic rays and travel times through a 3D model of the Earth. LLNL is using this for earthquake location and global tomography efforts and such codes are of great interest to the Earth Science community.

  10. Basin geometry and cumulative offsets in the Eastern Transverse Ranges, southern California: Implications for transrotational deformation along the San Andreas fault system

    USGS Publications Warehouse

    Langenheim, V.E.; Powell, R.E.

    2009-01-01

    The Eastern Transverse Ranges, adjacent to and southeast of the big left bend of the San Andreas fault, southern California, form a crustal block that has rotated clockwise in response to dextral shear within the San Andreas system. Previous studies have indicated a discrepancy between the measured magnitudes of left slip on through-going east-striking fault zones of the Eastern Transverse Ranges and those predicted by simple geometric models using paleomagnetically determined clockwise rotations of basalts distributed along the faults. To assess the magnitude and source of this discrepancy, we apply new gravity and magnetic data in combination with geologic data to better constrain cumulative fault offsets and to define basin structure for the block between the Pinto Mountain and Chiriaco fault zones. Estimates of offset from using the length of pull-apart basins developed within left-stepping strands of the sinistral faults are consistent with those derived by matching offset magnetic anomalies and bedrock patterns, indicating a cumulative offset of at most ???40 km. The upper limit of displacements constrained by the geophysical and geologic data overlaps with the lower limit of those predicted at the 95% confidence level by models of conservative slip located on margins of rigid rotating blocks and the clockwise rotation of the paleomagnetic vectors. Any discrepancy is likely resolved by internal deformation within the blocks, such as intense deformation adjacent to the San Andreas fault (that can account for the absence of basins there as predicted by rigid-block models) and linkage via subsidiary faults between the main faults. ?? 2009 Geological Society of America.

  11. Three-dimensional micro-roughness of a pseudotachylyte-bearing fault surface

    NASA Astrophysics Data System (ADS)

    Resor, P. G.; Griffith, W.; Di Toro, G.

    2011-12-01

    Dynamic friction experiments in granitoid or gabbroic rocks that achieve earthquake slip velocities reveal significant weakening by melt-lubrication of the sliding surfaces. Extrapolation of these experimental results to seismic source depths (> 7 km) suggests that the slip weakening distance (Dw) over which this transition occurs is < 10 cm. The physics of this lubrication in the presence of a fluid (melt) is controlled by surface micro-topography. In order to characterize fault surface micro-roughness and its evolution during dynamic slip events on natural faults, we have undertaken an analysis of three-dimensional (3D) fault surface microtopography and its causes on a pseudotachylyte-bearing fault. The solidification of frictional melt soon after seismic slip ceases "freezes in" earthquake source geometries, however it also precludes the development of extensive fault surface exposures that have enabled direct studies of fault surface roughness. We have overcome this difficulty by imaging the intact 3D geometry of the fault using high-resolution X-ray computed tomography (CT). Samples (2 cm diameter cores) from a wavy fault segment cutting tonalites of the Gole Larghe fault zone, Italy were scanned at the University of Texas High Resolution X-ray CT Facility, using an Xradia MicroCT scanner with a 70 kV X-ray source. Individual voxels (3D pixels) are ~32 ?m across. Fault geometry is thus imaged over ~4 orders of magnitude from the micron scale up to Dw. The pseudotachylyte-bearing fault surface is imaged as a tabular body of intermediate X-ray attenuation crosscutting high attenuation biotite and low attenuation quartz and feldspar of the surrounding tonalite. We extract the fault surfaces (contact between the pseudotachylyte bearing fault zone and the wall rock) using integrated manual mapping, automated edge detection, and statistical evaluation. This approach results in a digital elevation model over > 90% of the fault surface for a sample from an extensional bend along the fault. Fourier spectral analysis of this surface reveals that roughness in both slip-parallel and slip-perpendicular directions exhibit approximate power-law scaling, however best-fit linear slopes are significantly less than 3, consistent with self-affine rather than self-similar scaling. The power spectra appear to show a break in slope at ~3.2 mm, approximately the grain-scale of the tonalite. Below this scale the power spectra of both slip-parallel and perpendicular profiles exhibit steeper slopes with greater slip-perpendicular roughness (higher power), while at larger wavelengths the slopes are lower, but identical irrespective of direction. Surprisingly, although relatively rougher at sub-grain-scale wavelengths than typical fractures, the surface does not exhibit extensive evidence of preferential melting of low temperature minerals, suggesting that, at least along this portion of the fault, microroughness evolution is not driven entirely by the thermodynamics of melting. This may imply that coseismic melt generation occurred primarily in contractional bends of the fault.

  12. Geomorphological maps and 3d models in cave research

    NASA Astrophysics Data System (ADS)

    Ballesteros, Daniel; Jiménez-Sánchez, Montserrat; José Domínguez-Cuesta, María

    2013-04-01

    Cave geomorphological processes and features can be studied by geomorphological maps although topographic maps, aerial photos and GPS are not available. Methods in cave geomorphological mapping are conditioned by cave environment configuration, the need of using speleological techniques, and limitations arising from the projection of the 3D data from the cave to a 2D plan. Some of our previous works in the Cantabrian Mountains and Cantabrian Coast (NW Spain) established the approach of the design of cave geomorphological maps and its legend. Today we are improving the display of cave process combining geomorphological maps and 3d models based on the experience obtained from the research of one cave from the Cantabrian Coast and four caves in the Picos de Europa National Park (funded by GEOCAVE project, Spanish National Parks Agency). The five caves are developed in Carboniferous limestone affected by faults and thrusts. The method of work includes: 1) the elaboration of the cave survey at 1:50 to 1:500 scale; 2) the check of the cave survey of three caves by closed loops; 3) the mapping of cave features based on the performed survey; 4) the 3d modeling of the caves approximating each survey shoot by an octagonal prism; and 5) the implementation and management of the survey and geomorphological map in a Geographic Information System. Based on the survey, the cavities are small caves to deep alpine shafts with 281 to 4,438 m length and up to 738 m deep. The precision of the cave maps only could be estimated in two caves at a cavity scale, displaying both of them a 2.49 % error. The prisms of the 3d model was classified into four groups according to the morphology of the cave passage: 1) canyons, 2) phreatic and epiphreatic tubes, 3) soutirage conduits, 4) mixed forms composed by phreatic and epiphreatic tubes modified by fluvial incision, 5) pitches and 6) irregular passages enlarged strongly by gravity process. According to our previous works geomorphological features were classified using genetic and morphological criteria in four groups: 1) fluviokarst features; 2) speleothems; 3) gravity forms; and 4) anthropogenic features. Canyons passages usually include vadose erosive forms and few dripstones and flowstones; the phreatic and epiphreatic tubes frequently display many phreatic erosive features, fluvial and torrential deposits, flowstone, dripstone and few and small breakdown deposits; the soutirage conduits shows phreatic erosive features and few dripstone and gravity deposit removed from upper passages; the mixed forms combine the features of canyons and phreatic and epiphreatic tubes detailed above; the pitches display small dripstone and flowstone in the walls and gravity deposits or vadose erosive forms in its bottom; and the passages enlarged strongly by gravity process contain big talus deposits and some small slides that modified previous fluviokarst and speleothems features. Consequently, the results evidence that the geometry and geomorphology of the cavities can be defined together combining the geomorphological maps and 3d model in order to link the morphology of the conduits with the cave processes.

  13. What is Descriptive Geometry for ? Hellmuth Stachel, Institute of Geometry, TU Vienna

    E-print Network

    Nawratil, Georg

    This is a pleading for Descriptive Geometry. From the very first, Descriptive Geometry is a method to study 3D' intellectual capability of space perception. Drawings are the guide to geometry but not the main aim. 1 Geometry' encompasses the analysis of 3D objects by means of graphical or mathematical methods applied to 2

  14. PLOT3D user's manual

    NASA Technical Reports Server (NTRS)

    Walatka, Pamela P.; Buning, Pieter G.; Pierce, Larry; Elson, Patricia A.

    1990-01-01

    PLOT3D is a computer graphics program designed to visualize the grids and solutions of computational fluid dynamics. Seventy-four functions are available. Versions are available for many systems. PLOT3D can handle multiple grids with a million or more grid points, and can produce varieties of model renderings, such as wireframe or flat shaded. Output from PLOT3D can be used in animation programs. The first part of this manual is a tutorial that takes the reader, keystroke by keystroke, through a PLOT3D session. The second part of the manual contains reference chapters, including the helpfile, data file formats, advice on changing PLOT3D, and sample command files.

  15. 3D printing in dentistry.

    PubMed

    Dawood, A; Marti, B Marti; Sauret-Jackson, V; Darwood, A

    2015-12-11

    3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery. PMID:26657435

  16. Microearthquakes illuminate the deep structure of the endglacial Pärvie fault, northern Sweden

    NASA Astrophysics Data System (ADS)

    Lindblom, Eva; Lund, Björn; Tryggvason, Ari; Uski, Marja; Bödvarsson, Reynir; Juhlin, Christopher; Roberts, Roland

    2015-06-01

    At 155 km, the Pärvie fault is the world's longest known endglacial fault (EGF). It is located in northernmost Sweden in a region where several kilometre-scale EGFs have been identified. Based on studies of Quaternary deposits, landslides and liquefaction structures, these faults are inferred to have ruptured as large earthquakes when the latest ice sheet disappeared from the region, some 9500 yr ago. The EGFs still exhibit relatively high seismic activity, and here we present new earthquake data from northern Sweden in general and the Pärvie fault in particular. More than 1450 earthquakes have been recorded in Sweden north of 66° latitude in the years 2000-2013. There is a remarkable correlation between this seismicity and the mapped EGF scarps. We find that 71 per cent of the observed earthquakes north of 66° locate within 30 km to the southeast and 10 km to the northwest of the EGFs, which is consistent with the EGFs' observed reverse faulting mechanisms, with dips to the southeast. In order to further investigate the seismicity along the Pärvie fault we installed a temporary seismic network in the area between 2007 and 2010. In addition to the routine automatic detection and location algorithm, we devised a waveform cross-correlation technique which resulted in a 50 per cent increase of the catalogue and a total of 1046 events along the Pärvie fault system between 2003 and 2013. The earthquakes were used to establish an improved velocity model for the area, using 3-D local earthquake tomography. The resulting 3-D velocity model shows smooth, minor velocity variations in the area. All events were relocated in this new 3-D model. A tight cluster on the central part of the Pärvie fault, where the rate of seismicity is the highest, could be relocated with high precision relative location. We performed depth phase analysis on 40 of the larger events to further constrain the hypocentral locations. We find that the seismicity on the Pärvie fault correlates very well with the mapped surface trace of the fault. The events do not align along a well-defined fault plane at depth but form a zone of seismicity that dips between 30° and 60° to the southeast of the surface fault trace, with distinct along-strike variations. The seismic zone extends to approximately 35 km depth. Using this geometry and earthquake scaling relations, we estimate that the endglacial Pärvie earthquake had a magnitude of 8.0 ± 0.4.

  17. A 3-D SAR approach to IFSAR processing

    SciTech Connect

    DOERRY,ARMIN W.; BICKEL,DOUGLAS L.

    2000-03-01

    Interferometric SAR (IFSAR) can be shown to be a special case of 3-D SAR image formation. In fact, traditional IFSAR processing results in the equivalent of merely a super-resolved, under-sampled, 3-D SAR image. However, when approached as a 3-D SAR problem, a number of IFSAR properties and anomalies are easily explained. For example, IFSAR decorrelation with height is merely ordinary migration in 3-D SAR. Consequently, treating IFSAR as a 3-D SAR problem allows insight and development of proper motion compensation techniques and image formation operations to facilitate optimal height estimation. Furthermore, multiple antenna phase centers and baselines are easily incorporated into this formulation, providing essentially a sparse array in the elevation dimension. This paper shows the Polar Format image formation algorithm extended to 3 dimensions, and then proceeds to apply it to the IFSAR collection geometry. This suggests a more optimal reordering of the traditional IFSAR processing steps.

  18. Current progress in 3D printing for cardiovascular tissue engineering.

    PubMed

    Mosadegh, Bobak; Xiong, Guanglei; Dunham, Simon; Min, James K

    2015-06-01

    3D printing is a technology that allows the fabrication of structures with arbitrary geometries and heterogeneous material properties. The application of this technology to biological structures that match the complexity of native tissue is of great interest to researchers. This mini-review highlights the current progress of 3D printing for fabricating artificial tissues of the cardiovascular system, specifically the myocardium, heart valves, and coronary arteries. In addition, how 3D printed sensors and actuators can play a role in tissue engineering is discussed. To date, all the work with building 3D cardiac tissues have been proof-of-principle demonstrations, and in most cases, yielded products less effective than other traditional tissue engineering strategies. However, this technology is in its infancy and therefore there is much promise that through collaboration between biologists, engineers and material scientists, 3D bioprinting can make a significant impact on the field of cardiovascular tissue engineering. PMID:25775166

  19. Curved Fault Dynamic Rupture Study: Wasatch Fault Salt Lake City Segment

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Archuleta, R. J.; Smith, R. B.

    2011-12-01

    Faults are not planar; the curvature of the fault provides us useful information on the earthquake mechanics and faulting (Scholz, 1990). Fault geometry has a profound impact on both static aspect (stress distribution in the fault zone) and dynamic aspect (facilitation and impedance of the fault rupture process) of some fundamental earthquake problems. In most earthquake simulations, planar/piece-wise planar faults are used for numerical simplicity. For real earthquake scenarios, especially ground motion prediction, the eligibility of using simplified planar fault geometry needs to be validated, otherwise the simplification might bias the final conclusion. We analyze the rupture process and ground motion statistics in earthquake simulations for Wasatch Fault -Salt Lake City segment- with different fault configurations. We use a finite element method (Ma & Liu, 2006) to simulate the dynamics of a propagating rupture. We consider various initial stress distribution schemes on the fault (uniform, depth-dependent, random). We want to understand 1) how does the fault geometry itself influence the physical rupture process? and 2) what effect does the curvature have on redistributing the initial stresses on the fault? We will monitor the Coulomb stress change near the fault (Liu et al, 2010). This may provide some indication of the interaction between discontinuous fault segments and dynamic triggering as well as the distribution of aftershocks/foreshocks in relation to the fault geometry.

  20. A “mesh” of crossing faults: Fault networks of southern California

    NASA Astrophysics Data System (ADS)

    Janecke, S. U.

    2009-12-01

    Detailed geologic mapping of active fault systems in the western Salton Trough and northern Peninsular Ranges of southern California make it possible to expand the inventory of mapped and known faults by compiling and updating existing geologic maps, and analyzing high resolution imagery, LIDAR, InSAR, relocated hypocenters and other geophysical datasets. A fault map is being compiled on Google Earth and will ultimately discriminate between a range of different fault expressions: from well-mapped faults to subtle lineaments and geomorphic anomalies. The fault map shows deformation patterns in both crystalline and basinal deposits and reveals a complex fault mesh with many curious and unexpected relationships. Key findings are: 1) Many fault systems have mutually interpenetrating geometries, are grossly coeval, and allow faults to cross one another. A typical relationship reveals a dextral fault zone that appears to be continuous at the regional scale. In detail, however, there are no continuous NW-striking dextral fault traces and instead the master dextral fault is offset in a left-lateral sense by numerous crossing faults. Left-lateral faults also show small offsets where they interact with right lateral faults. Both fault sets show evidence of Quaternary activity. Examples occur along the Clark, Coyote Creek, Earthquake Valley and Torres Martinez fault zones. 2) Fault zones cross in other ways. There are locations where active faults continue across or beneath significant structural barriers. Major fault zones like the Clark fault of the San Jacinto fault system appears to end at NE-striking sinistral fault zones (like the Extra and Pumpkin faults) that clearly cross from the SW to the NE side of the projection of the dextral traces. Despite these blocking structures, there is good evidence for continuation of the dextral faults on the opposite sides of the crossing fault array. In some instances there is clear evidence (in deep microseismic alignments of hypocenters) that the master dextral faults zones pass beneath shallower crossing fault arrays above them and this mechanism may transfer strain through the blocking zones. 3) The curvature of strands of the Coyote Creek fault and the Elsinore fault are similar along their SE 60 km. The scale, locations and concavity of bends are so similar that their shape appears to be coordinated. The matching contractional and extensional bends suggests that originally straighter dextral fault zones may be deforming in response of coeval sinistral deformation between, beneath, and around them. 4) Deformation is strongly domainal with one style or geometry of structure dominating in one area then another in an adjacent area. Boundaries may be abrupt. 5) There are drastic lateral changes in the width of damage zones adjacent to master faults. Outlines of the deformation related to some dextral fault zones resemble a snake that has ingested a squirming cat or soccer ball. 6) A mesh of interconnected faults seems to transfer slip back and forth between structures. 7) Scarps are not necessarily more abundant on the long master faults than on connector or crossing faults. Much remains to be learned upon completion the fault map.

  1. Probabilistic Fault Displacement Hazard Assessment For Pipelines, Mad Dog and Atlantis Field Developments, Deepwater Gulf of Mexico

    NASA Astrophysics Data System (ADS)

    Angell, M.; Hanson, K.; Swan, F.; Youngs, R.; Abramson, H.

    2004-12-01

    Seafloor faults having strong geomorphic expression and evidence for late Quaternary activity (i.e. < ~150,000 years) are common geologic features associated with the Sigsbee Escarpment. Waterbottom maps derived from exploration 3D multichannel seismic data provided an early indication that several zones of seafloor faults are in the vicinity of the Mad Dog and Atlantis prospect areas. As part of the site investigation activities for field development BP initiated a study to characterize the potential hazard due to fault displacement. The fault displacement hazard study consists of five components: 1) a site-wide structural geologic characterization of the style and origin of active faulting and fault-related deformation; 2) development of a late Quaternary stratigraphic model to evaluate the history, recency, and rate of fault activity at the site; 3) detailed characterization of faulting within limited study areas designated to capture fault behavior in areas of potential facilities development; 4) a general description of the relationship between Quaternary active faulting and slope failure processes within the field area; and 5) a probabilistic fault displacement hazard analysis (PFDHA) of the potential for fault rupture within the designated study areas that relates annual frequency of recurrence of faulting events to the size of the event. Changes in the style and origin of faulting and deformation of shallow (suprasalt) sediment across the individual field areas primarily is due to differences in the depth, geometry, and movement history of the underlying Sigsbee Salt Nappe. These relationships and the resulting geologic model for structural evolution of the suprasalt section has been used effectively to assess the site-wide geohazards not only for faulting, but also indirectly for slope failure and mass-gravity flows. Hazard from potential seafloor offset at fault crossings is judged to be moderate to low. Fault offsets of the shallowest horizons (less than 15 thousand years old) are typically less than ten meters to several tens of meters. Fault slip rates are on the order of tenths to several tens of meters-per-thousand-years (m/kyr, also millimeters-per-year, or mm/yr), with most values in the range of 2-10 m/kyr. Similarly, the probabilistic annual recurrence of 1-meter events is typically less than 10-3. These studies demonstrate that the presence of potentially active faults does not preclude safe development of seafloor facilities. To evaluate risk associated with potential seafloor faulting, integrated hazard studies can and should be conducted in the early stages of project development, with an underlying intent to understand the causative processes and quantitatively and explicitly evaluate the locations, magnitude and recurrence potential of displacement events.

  2. The 3D geological model of the 1963 Vajont rockslide, reconstructed with implicit surface methods

    NASA Astrophysics Data System (ADS)

    Bistacchi, Andrea; Massironi, Matteo; Francese, Roberto; Giorgi, Massimo; Taller, Claudio

    2015-04-01

    The Vajont rockslide has been the object of several studies because of its catastrophic consequences and of its particular evolution. Several qualitative or quantitative models have been presented in the last 50 years, but a complete explanation of all the relevant geological and mechanical processes remains elusive. In order to better understand the mechanics and dynamics of the 1963 event, we have reconstructed the first 3D geological model of the rockslide, which allowed us to accurately investigate the rockslide structure and kinematics. The input data for the model consisted in: pre- and post-rockslide geological maps, pre- and post-rockslide orthophotos, pre- and post-rockslide digital elevation models, structural data, boreholes, and geophysical data (2D and 3D seismics and resistivity). All these data have been integrated in a 3D geological model implemented in Gocad®, using the implicit surface modelling method. Results of the 3D geological model include the depth and geometry of the sliding surface, the volume of the two lobes of the rockslide accumulation, kinematics of the rockslide in terms of the vector field of finite displacement, and high quality meshes useful for mechanical and hydrogeological simulations. The latter can include information about the stratigraphy and internal structure of the rock masses and allow tracing the displacement of different material points in the rockslide from the pre-1963-failure to the post-rockslide state. As a general geological conclusion, we may say that the 3D model allowed us to recognize very effectively a sliding surface, whose non-planar geometry is affected by the interference pattern of two regional-scale fold systems. The rockslide is partitioned into two distinct and internally continuous rock masses with a distinct kinematics, which were characterised by a very limited internal deformation during the slide. The continuity of these two large blocks points to a very localized deformation, occurring along a thin, continuous and weak cataclastic horizon. Finally, the chosen modelling strategy, based on both traditional "explicit" and implicit techniques, was found to be very effective for reconstructing complex folded and faulted geological structures, and could be applied also to other geological environments.

  3. A New Perspective on Fault Geometry and Slip Distribution of the 2009 Dachaidan Mw 6.3 Earthquake from InSAR Observations.

    PubMed

    Liu, Yang; Xu, Caijun; Wen, Yangmao; Fok, Hok Sum

    2015-01-01

    On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake. This study utilizes the Envisat ASAR images from descending Track 319 and ascending Track 455 for capturing the coseismic deformation resulting from this event, indicating that the earthquake fault rupture does not reach to the earth's surface. We then propose a four-segmented fault model to investigate the coseismic deformation by determining the fault parameters, followed by inverting slip distribution. The preferred fault model shows that the rupture depths for all four fault planes mainly range from 2.0 km to 7.5 km, comparatively shallower than previous results up to ~13 km, and that the slip distribution on the fault plane is complex, exhibiting three slip peaks with a maximum of 2.44 m at a depth between 4.1 km and 4.9 km. The inverted geodetic moment is 3.85 × 10(18) Nm (Mw 6.36). The 2009 event may rupture from the northwest to the southeast unilaterally, reaching the maximum at the central segment. PMID:26184210

  4. A New Perspective on Fault Geometry and Slip Distribution of the 2009 Dachaidan Mw 6.3 Earthquake from InSAR Observations

    PubMed Central

    Liu, Yang; Xu, Caijun; Wen, Yangmao; Fok, Hok Sum

    2015-01-01

    On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake. This study utilizes the Envisat ASAR images from descending Track 319 and ascending Track 455 for capturing the coseismic deformation resulting from this event, indicating that the earthquake fault rupture does not reach to the earth’s surface. We then propose a four-segmented fault model to investigate the coseismic deformation by determining the fault parameters, followed by inverting slip distribution. The preferred fault model shows that the rupture depths for all four fault planes mainly range from 2.0 km to 7.5 km, comparatively shallower than previous results up to ~13 km, and that the slip distribution on the fault plane is complex, exhibiting three slip peaks with a maximum of 2.44 m at a depth between 4.1 km and 4.9 km. The inverted geodetic moment is 3.85 × 1018 Nm (Mw 6.36). The 2009 event may rupture from the northwest to the southeast unilaterally, reaching the maximum at the central segment. PMID:26184210

  5. Bioprinting of 3D hydrogels.

    PubMed

    Stanton, M M; Samitier, J; Sánchez, S

    2015-08-01

    Three-dimensional (3D) bioprinting has recently emerged as an extension of 3D material printing, by using biocompatible or cellular components to build structures in an additive, layer-by-layer methodology for encapsulation and culture of cells. These 3D systems allow for cell culture in a suspension for formation of highly organized tissue or controlled spatial orientation of cell environments. The in vitro 3D cellular environments simulate the complexity of an in vivo environment and natural extracellular matrices (ECM). This paper will focus on bioprinting utilizing hydrogels as 3D scaffolds. Hydrogels are advantageous for cell culture as they are highly permeable to cell culture media, nutrients, and waste products generated during metabolic cell processes. They have the ability to be fabricated in customized shapes with various material properties with dimensions at the micron scale. 3D hydrogels are a reliable method for biocompatible 3D printing and have applications in tissue engineering, drug screening, and organ on a chip models. PMID:26066320

  6. 3-D Mesh Generation Nonlinear Systems

    Energy Science and Technology Software Center (ESTSC)

    1994-04-07

    INGRID is a general-purpose, three-dimensional mesh generator developed for use with finite element, nonlinear, structural dynamics codes. INGRID generates the large and complex input data files for DYNA3D, NIKE3D, FACET, and TOPAZ3D. One of the greatest advantages of INGRID is that virtually any shape can be described without resorting to wedge elements, tetrahedrons, triangular elements or highly distorted quadrilateral or hexahedral elements. Other capabilities available are in the areas of geometry and graphics. Exact surfacemore »equations and surface intersections considerably improve the ability to deal with accurate models, and a hidden line graphics algorithm is included which is efficient on the most complicated meshes. The primary new capability is associated with the boundary conditions, loads, and material properties required by nonlinear mechanics programs. Commands have been designed for each case to minimize user effort. This is particularly important since special processing is almost always required for each load or boundary condition.« less

  7. Automated texture registration on 3D models

    NASA Astrophysics Data System (ADS)

    Pelagotti, A.; Uccheddu, F.; Picchioni, F.

    2011-11-01

    3D models are often lacking a photorealistic appearance, due to low quality of the acquired texture, or to the complete absence of it. Moreover, especially in case of reality based models, it is often of specific interest to texture with images different from photos, like multispectral/multimodal views (InfraRed, X-rays, UV fluorescence etc), or images taken in different moments in time. In this work, a fully automatic approach for texture mapping is proposed. The method relies on the automatic extraction from the model geometry of appropriate depth maps, in form of images, whose pixels maintain an exact correspondence with vertices of the 3D model. A multiresolution greedy method is then proposed to generate the candidate depth maps which could be related with the given texture. In order to select the best match, a suited similarity measure is computed, based on Maximixation of Mutual Information (MMI). 3D texturing is then applied to the portion of the model which is visualized in the texture.

  8. The effects of lithology and initial fault angle in physical models of fault-propagation folds 

    E-print Network

    McLain, Christopher Thomas

    2001-01-01

    Experimentally deformed physical rock models are used to examine the effects of changing mechanical stratigraphy and initial fault angle on the development of fault-propagation folds over a flat-ramp-flat thrust geometry. This study also...

  9. GRAPHICS PROGRAMMING SECTION D -JAVA 3D

    E-print Network

    Hill, Gary

    GRAPHICS PROGRAMMING SECTION D - JAVA 3D 1SECTION D - GRAPHICS 3-D........................................................................................... 2 30 Graphics 3D: Introduction to Java 3D........................................................................................ 78 ©Gary Hill September 2004 Java 3-D 1 of 13 #12;GRAPHICS PROGRAMMING SECTION D - GRAPHICS 3-D 30

  10. Lattice Boltzmann Method for 3-D Flows with Curved Boundary

    NASA Technical Reports Server (NTRS)

    Mei, Renwei; Shyy, Wei; Yu, Dazhi; Luo, Li-Shi

    2002-01-01

    In this work, we investigate two issues that are important to computational efficiency and reliability in fluid dynamics applications of the lattice, Boltzmann equation (LBE): (1) Computational stability and accuracy of different lattice Boltzmann models and (2) the treatment of the boundary conditions on curved solid boundaries and their 3-D implementations. Three athermal 3-D LBE models (D3QI5, D3Ql9, and D3Q27) are studied and compared in terms of efficiency, accuracy, and robustness. The boundary treatment recently developed by Filippova and Hanel and Met et al. in 2-D is extended to and implemented for 3-D. The convergence, stability, and computational efficiency of the 3-D LBE models with the boundary treatment for curved boundaries were tested in simulations of four 3-D flows: (1) Fully developed flows in a square duct, (2) flow in a 3-D lid-driven cavity, (3) fully developed flows in a circular pipe, and (4) a uniform flow over a sphere. We found that while the fifteen-velocity 3-D (D3Ql5) model is more prone to numerical instability and the D3Q27 is more computationally intensive, the 63Q19 model provides a balance between computational reliability and efficiency. Through numerical simulations, we demonstrated that the boundary treatment for 3-D arbitrary curved geometry has second-order accuracy and possesses satisfactory stability characteristics.

  11. An Automated 3d Indoor Topological Navigation Network Modelling

    NASA Astrophysics Data System (ADS)

    Jamali, A.; Rahman, A. A.; Boguslawski, P.; Gold, C. M.

    2015-10-01

    Indoor navigation is important for various applications such as disaster management and safety analysis. In the last decade, indoor environment has been a focus of wide research; that includes developing techniques for acquiring indoor data (e.g. Terrestrial laser scanning), 3D indoor modelling and 3D indoor navigation models. In this paper, an automated 3D topological indoor network generated from inaccurate 3D building models is proposed. In a normal scenario, 3D indoor navigation network derivation needs accurate 3D models with no errors (e.g. gap, intersect) and two cells (e.g. rooms, corridors) should touch each other to build their connections. The presented 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. For reducing time and cost of indoor building data acquisition process, Trimble LaserAce 1000 as surveying instrument is used. The modelling results were validated against an accurate geometry of indoor building environment which was acquired using Trimble M3 total station.

  12. A 3-D crustal velocity structure across the Variscides of southwest Ireland

    NASA Astrophysics Data System (ADS)

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

    2003-04-01

    In the VARNET-96 experiment three seismic refraction profiles were acquired to examine the crustal structure in the south-west of Ireland. The shotpoint geometry allowed for both in-line and off-line fan shot recordings on the three profiles. Results of 3-D inversion modelling illustrate that there is pervasive lateral heterogeneity of the sedimentary and crustal velocity structure 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 beneath Dingle Bay and the Kenmare River region 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 28-29 km at the south coast to 32-33 km beneath the Dingle-Shannon Basin. Pervasive Variscan deformation appears to be confined to the sedimentary and upper crustal structure thus 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 offshore sedimentary basins.

  13. 3D cinema to 3DTV content adaptation

    NASA Astrophysics Data System (ADS)

    Yasakethu, L.; Blondé, L.; Doyen, D.; Huynh-Thu, Q.

    2012-03-01

    3D cinema and 3DTV have grown in popularity in recent years. Filmmakers have a significant opportunity in front of them given the recent success of 3D films. In this paper we investigate whether this opportunity could be extended to the home in a meaningful way. "3D" perceived from viewing stereoscopic content depends on the viewing geometry. This implies that the stereoscopic-3D content should be captured for a specific viewing geometry in order to provide a satisfactory 3D experience. However, although it would be possible, it is clearly not viable, to produce and transmit multiple streams of the same content for different screen sizes. In this study to solve the above problem, we analyze the performance of six different disparity-based transformation techniques, which could be used for cinema-to-3DTV content conversion. Subjective tests are performed to evaluate the effectiveness of the algorithms in terms of depth effect, visual comfort and overall 3D quality. The resultant 3DTV experience is also compared to that of cinema. We show that by applying the proper transformation technique on the content originally captured for cinema, it is possible to enhance the 3DTV experience. The selection of the appropriate transformation is highly dependent on the content characteristics.

  14. Recovering 3D tumor locations from 2D bioluminescence images

    E-print Network

    Huang, Xiaolei

    Recovering 3D tumor locations from 2D bioluminescence images Xiaolei Huang1 , Dimitris Metaxas1 Bioluminescence imaging (BLI) is an emerging technique for sensitive and nonin- vasive imaging, which can be used bioluminescence images, then register and visualize the reconstructed tumor with detailed animal geometry

  15. From 3D view to 3D print

    NASA Astrophysics Data System (ADS)

    Dima, M.; Farisato, G.; Bergomi, M.; Viotto, V.; Magrin, D.; Greggio, D.; Farinato, J.; Marafatto, L.; Ragazzoni, R.; Piazza, D.

    2014-08-01

    In the last few years 3D printing is getting more and more popular and used in many fields going from manufacturing to industrial design, architecture, medical support and aerospace. 3D printing is an evolution of bi-dimensional printing, which allows to obtain a solid object from a 3D model, realized with a 3D modelling software. The final product is obtained using an additive process, in which successive layers of material are laid down one over the other. A 3D printer allows to realize, in a simple way, very complex shapes, which would be quite difficult to be produced with dedicated conventional facilities. Thanks to the fact that the 3D printing is obtained superposing one layer to the others, it doesn't need any particular work flow and it is sufficient to simply draw the model and send it to print. Many different kinds of 3D printers exist based on the technology and material used for layer deposition. A common material used by the toner is ABS plastics, which is a light and rigid thermoplastic polymer, whose peculiar mechanical properties make it diffusely used in several fields, like pipes production and cars interiors manufacturing. I used this technology to create a 1:1 scale model of the telescope which is the hardware core of the space small mission CHEOPS (CHaracterising ExOPlanets Satellite) by ESA, which aims to characterize EXOplanets via transits observations. The telescope has a Ritchey-Chrétien configuration with a 30cm aperture and the launch is foreseen in 2017. In this paper, I present the different phases for the realization of such a model, focusing onto pros and cons of this kind of technology. For example, because of the finite printable volume (10×10×12 inches in the x, y and z directions respectively), it has been necessary to split the largest parts of the instrument in smaller components to be then reassembled and post-processed. A further issue is the resolution of the printed material, which is expressed in terms of layers thickness, in the Z direction, and in drop-per-inch, in X and Y directions. 3D printing is also an easy and quick production technique, which can become useful in the ad-hoc realization of mechanical components for optical setups to be used in a laboratory for new concept studies and validation, reducing the manufacturing time. With this technique, indeed, it is possible to realize in few hours custom-made mechanical parts, without any specific knowledge and expertise in tool machinery, as long as the resolution and size are compliant with the requirements.

  16. Faulted Barn

    USGS Multimedia Gallery

    This barn is faulted through the middle; the moletrack is seen in the foreground with the viewer standing on the fault. From the air one can see metal roof panels of the barn that rotated as the barn was faulted....

  17. YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters

    NASA Astrophysics Data System (ADS)

    Schild, Jonas; Seele, Sven; Masuch, Maic

    2012-03-01

    Along with the success of the digitally revived stereoscopic cinema, events beyond 3D movies become attractive for movie theater operators, i.e. interactive 3D games. In this paper, we present a case that explores possible challenges and solutions for interactive 3D games to be played by a movie theater audience. We analyze the setting and showcase current issues related to lighting and interaction. Our second focus is to provide gameplay mechanics that make special use of stereoscopy, especially depth-based game design. Based on these results, we present YouDash3D, a game prototype that explores public stereoscopic gameplay in a reduced kiosk setup. It features live 3D HD video stream of a professional stereo camera rig rendered in a real-time game scene. We use the effect to place the stereoscopic effigies of players into the digital game. The game showcases how stereoscopic vision can provide for a novel depth-based game mechanic. Projected trigger zones and distributed clusters of the audience video allow for easy adaptation to larger audiences and 3D movie theater gaming.

  18. A Community Fault Model (CFM) for the Sichuan basin and Longmen Shan

    NASA Astrophysics Data System (ADS)

    Hubbard, J.; Shaw, J. H.; Plesch, A.; Riesner, M.; Smith, H.; Wang, M.; Durand-Riard, P.

    2012-12-01

    The 2008 M7.9 Wenchuan earthquake struck Sichuan Province, China, along the Longmen Shan fold-and-thrust belt. The rupture occurred in a region with no prior, historical earthquakes of comparable size, and in a region with low horizontal shortening. Thus, the event occurred with little prior warning based on current methods of seismic hazards assessment. In order to improve seismic hazards assessment, we have constructed a Community Fault Model (CFM) and Community Velocity Model (CVM) for the region, modeled after the Southern California CFM/CVM (Plesch et al., 2007). Here, we describe the CFM, which consists of 3D representations of the main active faults in the region. To facilitate model construction, we imported a variety of surface and subsurface datasets into Gocad, a 3D CAD tool. These include geological maps, fault maps, seismicity, focal mechanisms, well data, cross-sections, and seismic reflection profiles. We developed a quantitative technique for constructing fault surfaces using these datasets, described in Riesner et al. (2012). The region displays a variety of faulting styles. The Longmen Shan is a NE-SW-striking fold-and-thrust belt, characterized by a set of NW-dipping imbricated thrust ramps that sole into a deep detachment at ~15-20 km. This detachment rises to the SE along a blind thrust ramp (the Range Front thrust), and flattens to a shallower detachment that underlies much of the Sichuan basin (2-7 km depth). Many of the active faults in the basin sole to this shallow detachment, which is localized in a Triassic evaporite sequence. There is also evidence of deeper faulting within the Sichuan basin, as shown by the Weiyuan anticline and patches of seismicity at greater depth. These faults generally dip steeply, and may be thick-skinned or rise from a deeper detachment. The main fault that ruptured in the Wenchuan earthquake, the Beichuan fault, lies within the Longmen Shan and dips steeply. More shallowly dipping faults splay off of this fault to the SE; one of these (the Pengguan fault) also ruptured in the Wenchuan earthquake. Slip in the earthquake was highly oblique, with right-lateral motion. Consistent with this obliquity, we see evidence for the breakthrough of a new strike-slip fault to the NE of the mapped rupture in the Wenchuan earthquake based on seismicity patterns. To the north and south, the Longmen Shan is bounded by two large NW-SE to N-S-striking left-lateral strike-slip systems: the Kunlun to the north, and the Xianshuihe-Anninghe to the south. Although some faults are well-constrained by surface and subsurface data, others are represented only by a surface trace and sparse seismicity. When the geometry is unclear, we provide multiple alternative models. We plan to develop "quality rankings" for the faults based on data availability and community surveys. These rankings will be used to identify the preferred model when multiple alternatives are available. In addition to providing an integrative repository for fault studies and data, this model is intended to be used in a wide range of earthquake studies, including analysis of geodetic data to assess fault slip rates, simulations of the strong ground motion that will result from future earthquakes, and improvement of regional tomographic models. We will be releasing the fault model together with our 3D velocity model (Wang et al., 2012) to facilitate such studies.

  19. Speaking Volumes About 3-D

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In 1999, Genex submitted a proposal to Stennis Space Center for a volumetric 3-D display technique that would provide multiple users with a 360-degree perspective to simultaneously view and analyze 3-D data. The futuristic capabilities of the VolumeViewer(R) have offered tremendous benefits to commercial users in the fields of medicine and surgery, air traffic control, pilot training and education, computer-aided design/computer-aided manufacturing, and military/battlefield management. The technology has also helped NASA to better analyze and assess the various data collected by its satellite and spacecraft sensors. Genex capitalized on its success with Stennis by introducing two separate products to the commercial market that incorporate key elements of the 3-D display technology designed under an SBIR contract. The company Rainbow 3D(R) imaging camera is a novel, three-dimensional surface profile measurement system that can obtain a full-frame 3-D image in less than 1 second. The third product is the 360-degree OmniEye(R) video system. Ideal for intrusion detection, surveillance, and situation management, this unique camera system offers a continuous, panoramic view of a scene in real time.

  20. High resolution earthquake source mechanisms in a subduction zone: 3-D waveform simulations of aftershocks from the 2010 Mw 8.8 Chile rupture

    NASA Astrophysics Data System (ADS)

    Hicks, Stephen; Rietbrock, Andreas

    2015-04-01

    The earthquake rupture process is extremely heterogeneous. For subduction zone earthquakes in particular, it is vital to understand how structural variations in the overriding plate and downgoing slab may control slip style. The large-scale 3-D geometry of subduction plate boundaries is rapidly becoming well understood (e.g. Hayes et al., 2012); however, the nature of slip style along any finer-scale structures remains elusive. Regional earthquake moment tensor (RMT) inversion can shed light on faulting mechanisms. However, many traditional regional moment tensor inversions use simplified (1-D) Earth models (e.g. Agurto et al., 2012; Hayes et al., 2013) that only use the lowest frequency parts of the waveform, which may mask source complexity. As a result, we may have to take care when making small-scale interpretations about the causative fault and its slip style. This situation is compounded further by strong lateral variations in subsurface geology, as well as poor station coverage for recording offshore subduction earthquakes. A formal assessment of the resolving capability of RMT inversions in subduction zones is challenging and the application of 3-D waveform simulation techniques in highly heterogeneous media is needed. We generate 3-D waveform simulations of aftershocks from a large earthquake that struck Chile in 2010. The Mw 8.8 Maule earthquake is the sixth largest earthquake ever recorded. Following the earthquake, there was an international deployment of seismic stations in the rupture area, making this one of the best observed aftershock sequences to date. We therefore have a unique opportunity to compare recorded waveforms with simulated waveforms for many earthquakes, shedding light on the effect of 3-D heterogeneity on source imaging. We perform forward simulations using the spectral element wave propagation code, SPEFEM3D (e.g. Komatitsch et al., 2010) for a set of moderate-sized aftershocks (Mw 4.0-5.5). A detailed knowledge of velocity structure for the region as well as robust earthquake locations (Hicks et al., 2014) ensure that our 3-D simulations are robust. We perform regional moment tensor inversion using the ISOLA software package (Sokos & Zahradnik, 2008), incorporating 3-D Green's functions from the forward simulations. With this approach, we are able to test the resolving capability of traditional 1-D strategies. We find that focal mechanism dip and source depth are the parameters that are most biased parameters in 1-D RMT inversions, particularly for events that are located far offshore. We also describe and interpret observations of normal faulting earthquakes along the plate interface. This finding may have important implications for post-seismic fluid release.

  1. 3D Ultrasonic Wave Simulations for Structural Health Monitoring

    NASA Technical Reports Server (NTRS)

    Campbell, Leckey Cara A/; Miler, Corey A.; Hinders, Mark K.

    2011-01-01

    Structural health monitoring (SHM) for the detection of damage in aerospace materials is an important area of research at NASA. Ultrasonic guided Lamb waves are a promising SHM damage detection technique since the waves can propagate long distances. For complicated flaw geometries experimental signals can be difficult to interpret. High performance computing can now handle full 3-dimensional (3D) simulations of elastic wave propagation in materials. We have developed and implemented parallel 3D elastodynamic finite integration technique (3D EFIT) code to investigate ultrasound scattering from flaws in materials. EFIT results have been compared to experimental data and the simulations provide unique insight into details of the wave behavior. This type of insight is useful for developing optimized experimental SHM techniques. 3D EFIT can also be expanded to model wave propagation and scattering in anisotropic composite materials.

  2. 3D stereolithography printing of graphene oxide reinforced complex architectures

    NASA Astrophysics Data System (ADS)

    Lin, Dong; Jin, Shengyu; Zhang, Feng; Wang, Chao; Wang, Yiqian; Zhou, Chi; Cheng, Gary J.

    2015-10-01

    Properties of polymer based nanocomposites reply on distribution, concentration, geometry and property of nanofillers in polymer matrix. Increasing the concentration of carbon based nanomaterials, such as CNTs, in polymer matrix often results in stronger but more brittle material. Here, we demonstrated the first three-dimensional (3D) printed graphene oxide complex structures by stereolithography with good combination of strength and ductility. With only 0.2% GOs, the tensile strength is increased by 62.2% and elongation increased by 12.8%. Transmission electron microscope results show that the GOs were randomly aligned in the cross section of polymer. We investigated the strengthening mechanism of the 3D printed structure in terms of tensile strength and Young’s modulus. It is found that an increase in ductility of the 3D printed nanocomposites is related to increase in crystallinity of GOs reinforced polymer. Compression test of 3D GOs structure reveals the metal-like failure model of GOs nanocomposites.

  3. 3D stereolithography printing of graphene oxide reinforced complex architectures.

    PubMed

    Lin, Dong; Jin, Shengyu; Zhang, Feng; Wang, Chao; Wang, Yiqian; Zhou, Chi; Cheng, Gary J

    2015-10-30

    Properties of polymer based nanocomposites reply on distribution, concentration, geometry and property of nanofillers in polymer matrix. Increasing the concentration of carbon based nanomaterials, such as CNTs, in polymer matrix often results in stronger but more brittle material. Here, we demonstrated the first three-dimensional (3D) printed graphene oxide complex structures by stereolithography with good combination of strength and ductility. With only 0.2% GOs, the tensile strength is increased by 62.2% and elongation increased by 12.8%. Transmission electron microscope results show that the GOs were randomly aligned in the cross section of polymer. We investigated the strengthening mechanism of the 3D printed structure in terms of tensile strength and Young's modulus. It is found that an increase in ductility of the 3D printed nanocomposites is related to increase in crystallinity of GOs reinforced polymer. Compression test of 3D GOs structure reveals the metal-like failure model of GOs nanocomposites. PMID:26443263

  4. Geno3D: automatic comparative molecular modelling of protein.

    PubMed

    Combet, Christophe; Jambon, Martin; Deléage, Gilbert; Geourjon, Christophe

    2002-01-01

    Geno3D (http://geno3d-pbil.ibcp.fr) is an automatic web server for protein molecular modelling. Starting with a query protein sequence, the server performs the homology modelling in six successive steps: (i) identify homologous proteins with known 3D structures by using PSI-BLAST; (ii) provide the user all potential templates through a very convenient user interface for target selection; (iii) perform the alignment of both query and subject sequences; (iv) extract geometrical restraints (dihedral angles and distances) for corresponding atoms between the query and the template; (v) perform the 3D construction of the protein by using a distance geometry approach and (vi) finally send the results by e-mail to the user. PMID:11836238

  5. INTEGRATING DATA FROM 3D CAD AND 3D CAMERAS

    E-print Network

    Bosché, Frédéric

    , USA; teizer@mail.utexas.edu 3 Professor, Department of Civil Engineering, University of Waterloo camera, 3D CAD, data fusion, construction automation 1 PhD Candidate, Department of Civil Engineering, Department of Civil, Architectural and Environmental Engineering, University of Texas at Austin, TX, 78712

  6. 3dSS: 3D structural superposition.

    PubMed

    Sumathi, K; Ananthalakshmi, P; Roshan, M N A Md; Sekar, K

    2006-07-01

    3dSS is a web-based interactive computing server, primarily designed to aid researchers, to superpose two or several 3D protein structures. In addition, the server can be effectively used to find the invariant and common water molecules present in the superposed homologous protein structures. The molecular visualization tool RASMOL is interfaced with the server to visualize the superposed 3D structures with the water molecules (invariant or common) in the client machine. Furthermore, an option is provided to save the superposed 3D atomic coordinates in the client machine. To perform the above, users need to enter Protein Data Bank (PDB)-id(s) or upload the atomic coordinates in PDB format. This server uses a locally maintained PDB anonymous FTP server that is being updated weekly. This program can be accessed through our Bioinformatics web server at the URL http://cluster.physics.iisc.ernet.in/3dss/ or http://10.188.1.15/3dss/. PMID:16844975

  7. 3D modelling in salt tectonic context: the Crocodile minibasin in Sivas (Turkey)

    NASA Astrophysics Data System (ADS)

    Collon, Pauline; Pichat, Alexandre; Kergaravat, Charlie; Botella, Arnaud; Caumon, Guillaume; Favreau, Océane; Fuss, Gaétan; Godefroy, Gabriel; Lerat, Marine; Mazuyer, Antoine; Parquer, Marion; Charreau, Julien; Callot, Jean-Paul; Ringenbach, Jean-Claude

    2015-04-01

    Impermeable, with a low density and acting as a viscous fluid at the geological time scale, salt plays a unique tectonic role favouring hydrocarbon trap formations. Halokinetic structures are various and difficult to image with classic seismic techniques. Thus, outcrop analogues are precious and sought after. Since the re-interpretation in September 2011 of its evaporite deposits, the Oligo-Miocene basin of Sivas (Turkey) is a new choice analogue for the study of salt tectonic with outstanding outcrops reflecting the variety of salt related structures: minibasins, diapirs, welds... While studying these structures requires an important field work, building 3D models becomes an interesting way to better help understanding the three-dimensional organisation and to further perform numerical simulations (e.g., restoration, potential field measurement campaign simulation). The complex geometries observed in salt tectonic context make these 3D geological models particularly challenging to build, especially when only outcrops data are available. We focus on the Crocodile minibasin (Sivas) and present a modelling strategy using a subtle combination of recently developed techniques. Available data are: a Digital Elevation Model, satellite images and associated interpreted bedding traces on topography, orientation measurements of the strata and a conceptual interpretation. Located on an ancient salt extrusion, this minibasin is filled with lacustrine and sabkha sediments. It is interpreted with a closed synclinal structure on North. On its southern part, a central diapir has risen up, separating two tightened synclinals. The salt surface is modelled first as a triangulated surface using a classical explicit surface patch construction method and a manual post-process mesh improvement. Then, the minibasin sediments are modelled with an implicit approach that considers interfaces as equipotentials of a 3D scalar field. This requires to build a volumetric mesh conformable to the salt surface to consistently disconnect both minibasin parts. This step is performed thanks to a local simplification of the salt surface that consists in replacing pinched parts by an equivalent fault/weld surface. The 3D scalar field is then computed with a Discrete Smooth Interpolation constrained by several information. Those information are weighted consistently with their relative uncertainty. Control points impose locally the scalar field value. They are set on interpreted bedding traces and on a surface located at 5m from the external salt surface boundary to account for the tangency of the sediment deposits in conformable parts of the minibasin. They are completed by constraints on the scalar field gradient orientation using dip measurements and a constant gradient constraint. The result highlights the remarkable geometry of this salt-tectonic related structure and underlines the usefulness of new modelling methods to ease a more automated generation of such tectonic features.

  8. 3D Polygon Rendering Pipeline Michael Kazhdan

    E-print Network

    Kazhdan, Michael

    3D Polygon Rendering Pipeline Michael Kazhdan (600.357 / 600.457) HB Ch. 12 FvDFH Ch. 6, 18.3 #12;3D Polygon Rendering · Many applications use rendering of 3D polygons with direct illumination #12;3D Polygon Rendering · Many applications use rendering of 3D polygons with direct illumination Crysis 3

  9. 3D-CONSOLE, APPLICATION INTERFACE

    E-print Network

    3D-CONSOLE, AN APPLICATION INTERFACE BASED ON X3D Brian Kristiansen Brian The aim of this report is to describe the design and implementation of a system named #16;3D-Console#17;. The ultimate goal for 3D-Console was to provide a 3-D user interface framework, which enabled users to work

  10. 3D-CONSOLE, APPLICATION INTERFACE

    E-print Network

    3D-CONSOLE, AN APPLICATION INTERFACE BASED ON X3D #22; SUPPLEMENTS Brian Kristiansen Brian Appendix A Project description English title: 3D-Console, an Application Interface based on X3D Advisor Kristiansen & Kristian Spangsege English project description We wish to implement a three-dimensional (3D

  11. Automatic Reconstruction of Spacecraft 3D Shape from Imagery

    NASA Astrophysics Data System (ADS)

    Poelman, C.; Radtke, R.; Voorhees, H.

    We describe a system that computes the three-dimensional (3D) shape of a spacecraft from a sequence of uncalibrated, two-dimensional images. While the mathematics of multi-view geometry is well understood, building a system that accurately recovers 3D shape from real imagery remains an art. A novel aspect of our approach is the combination of algorithms from computer vision, photogrammetry, and computer graphics. We demonstrate our system by computing spacecraft models from imagery taken by the Air Force Research Laboratory's XSS-10 satellite and DARPA's Orbital Express satellite. Using feature tie points (each identified in two or more images), we compute the relative motion of each frame and the 3D location of each feature using iterative linear factorization followed by non-linear bundle adjustment. The "point cloud" that results from this traditional shape-from-motion approach is typically too sparse to generate a detailed 3D model. Therefore, we use the computed motion solution as input to a volumetric silhouette-carving algorithm, which constructs a solid 3D model based on viewpoint consistency with the image frames. The resulting voxel model is then converted to a facet-based surface representation and is texture-mapped, yielding realistic images from arbitrary viewpoints. We also illustrate other applications of the algorithm, including 3D mensuration and stereoscopic 3D movie generation.

  12. Construction of programmable interconnected 3D microfluidic networks

    NASA Astrophysics Data System (ADS)

    Hunziker, Patrick R.; Wolf, Marc P.; Wang, Xueya; Zhang, Bei; Marsch, Stephan; Salieb-Beugelaar, Georgette B.

    2015-02-01

    Microfluidic systems represent a key-enabling platform for novel diagnostic tools for use at the point-of-care in clinical contexts as well as for evolving single cell diagnostics. The design of 3D microfluidic systems is an active field of development, but construction of true interconnected 3D microfluidic networks is still a challenge, in particular when the goal is rapid prototyping, accurate design and flexibility. We report a novel approach for the construction of programmable 3D microfluidic systems consisting of modular 3D template casting of interconnected threads to allow user-programmable flow paths and examine its structural characteristics and its modular function. To overcome problems with thread template casting reported in the literature, low-surface-energy polymer threads were used, that allow solvent-free production. Connected circular channels with excellent roundness and low diameter variability were created. Variable channel termination allowed programming a flow path on-the-fly, thus rendering the resulting 3D microfluidic systems highly customizable even after production. Thus, construction of programmable/reprogrammable fully 3D microfluidic systems by template casting of a network of interconnecting threads is feasible, leads to high-quality and highly reproducible, complex 3D geometries.

  13. Real time 3D and heterogeneous data fusion

    SciTech Connect

    Little, C.Q.; Small, D.E.

    1998-03-01

    This project visualizes characterization data in a 3D setting, in real time. Real time in this sense means collecting the data and presenting it before it delays the user, and processing faster than the acquisition systems so no bottlenecks occur. The goals have been to build a volumetric viewer to display 3D data, demonstrate projecting other data, such as images, onto the 3D data, and display both the 3D and projected images as fast as the data became available. The authors have examined several ways to display 3D surface data. The most effective was generating polygonal surface meshes. They have created surface maps form a continuous stream of 3D range data, fused image data onto the geometry, and displayed the data with a standard 3D rendering package. In parallel with this, they have developed a method to project real-time images onto the surface created. A key component is mapping the data on the correct surfaces, which requires a-priori positional information along with accurate calibration of the camera and lens system.

  14. FROMS3D: New Software for 3-D Visualization of Fracture Network System in Fractured Rock Masses

    NASA Astrophysics Data System (ADS)

    Noh, Y. H.; Um, J. G.; Choi, Y.

    2014-12-01

    A new software (FROMS3D) is presented to visualize fracture network system in 3-D. The software consists of several modules that play roles in management of borehole and field fracture data, fracture network modelling, visualization of fracture geometry in 3-D and calculation and visualization of intersections and equivalent pipes between fractures. Intel Parallel Studio XE 2013, Visual Studio.NET 2010 and the open source VTK library were utilized as development tools to efficiently implement the modules and the graphical user interface of the software. The results have suggested that the developed software is effective in visualizing 3-D fracture network system, and can provide useful information to tackle the engineering geological problems related to strength, deformability and hydraulic behaviors of the fractured rock masses.

  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 clear normal faults in the sediments well after the postrift period.

  16. Fracture properties analysis and discrete fracture network modelling of faulted tight limestones, Murge plateau, Italy

    NASA Astrophysics Data System (ADS)

    Zambrano, Miller; Tondi, Emanuele; Korneva, Irina; Panza, Elisa; Agosta, Fabrizio; Janiseck, Jean-Michel; Giorgioni, Maurizio

    2015-04-01

    The modelling of natural fracture in reservoirs requires, as input data, the results of previous detailed and accurate analysis of the 3D fracture network. These data could be derived from well logs and production tests (which however limit our understanding of the fracture geometry, intensity and distribution) and outcrop analogues. Data obtained applying scanline and scanarea methodologies on rocks exposed at the surface, in fact, allow the construction of more representative numerical models of natural fractured reservoirs. This work focuses on with the (DFN) modelling of natural fractures associated to strike-slip faults crosscutting tight carbonates, which are exposed along vertical walls and pavements of an inactive quarry of the Murge area, southern Italy. The studied outcrops expose the inner structure of two conjugate fault zones striking WNW-ESE and NNW-SSE, respectively. DFN models were built according to the spatial and dimensional properties computed for the natural fracture network. The results of these models show that the overall fault permeability is 3-to-4 orders of magnitude higher than the host rock permeability. The fault damage zones form the main fluid conduits, with the highest permeability values computed for fault-parallel fluid flow. Such a pronounced permeability anisotropy obtained for the fault damage zone is mainly related to the fracture dimension, both lengths and heights, and their aperture values.

  17. 3D Tissue Scaffolds BIOMATERIALS

    E-print Network

    properties. The platform encompasses several major classes of scaffolds including salt-leached scaffolds for assessing the impact of the physical and chemical properties of 3D tissue scaffolds on cellular response) that will enable companies to reliably characterize physical properties of their scaffold-based products. · We have

  18. SNL3dFace

    Energy Science and Technology Software Center (ESTSC)

    2007-07-20

    This software distribution contains MATLAB and C++ code to enable identity verification using 3D images that may or may not contain a texture component. The code is organized to support system performance testing and system capability demonstration through the proper configuration of the available user interface. Using specific algorithm parameters the face recognition system has been demonstrated to achieve a 96.6% verification rate (Pd) at 0.001 false alarm rate. The system computes robust facial featuresmore »of a 3D normalized face using Principal Component Analysis (PCA) and Fisher Linear Discriminant Analysis (FLDA). A 3D normalized face is obtained by alighning each face, represented by a set of XYZ coordinated, to a scaled reference face using the Iterative Closest Point (ICP) algorithm. The scaled reference face is then deformed to the input face using an iterative framework with parameters that control the deformed surface regulation an rate of deformation. A variety of options are available to control the information that is encoded by the PCA. Such options include the XYZ coordinates, the difference of each XYZ coordinates from the reference, the Z coordinate, the intensity/texture values, etc. In addition to PCA/FLDA feature projection this software supports feature matching to obtain similarity matrices for performance analysis. In addition, this software supports visualization of the STL, MRD, 2D normalized, and PCA synthetic representations in a 3D environment.« less

  19. 3D printing of microscopic bacterial communities

    PubMed Central

    Connell, Jodi L.; Ritschdorff, Eric T.; Whiteley, Marvin; Shear, Jason B.

    2013-01-01

    Bacteria communicate via short-range physical and chemical signals, interactions known to mediate quorum sensing, sporulation, and other adaptive phenotypes. Although most in vitro studies examine bacterial properties averaged over large populations, the levels of key molecular determinants of bacterial fitness and pathogenicity (e.g., oxygen, quorum-sensing signals) may vary over micrometer scales within small, dense cellular aggregates believed to play key roles in disease transmission. A detailed understanding of how cell–cell interactions contribute to pathogenicity in natural, complex environments will require a new level of control in constructing more relevant cellular models for assessing bacterial phenotypes. Here, we describe a microscopic three-dimensional (3D) printing strategy that enables multiple populations of bacteria to be organized within essentially any 3D geometry, including adjacent, nested, and free-floating colonies. In this laser-based lithographic technique, microscopic containers are formed around selected bacteria suspended in gelatin via focal cross-linking of polypeptide molecules. After excess reagent is removed, trapped bacteria are localized within sealed cavities formed by the cross-linked gelatin, a highly porous material that supports rapid growth of fully enclosed cellular populations and readily transmits numerous biologically active species, including polypeptides, antibiotics, and quorum-sensing signals. Using this approach, we show that a picoliter-volume aggregate of Staphylococcus aureus can display substantial resistance to ?-lactam antibiotics by enclosure within a shell composed of Pseudomonas aeruginosa. PMID:24101503

  20. 3D printing of microscopic bacterial communities.

    PubMed

    Connell, Jodi L; Ritschdorff, Eric T; Whiteley, Marvin; Shear, Jason B

    2013-11-12

    Bacteria communicate via short-range physical and chemical signals, interactions known to mediate quorum sensing, sporulation, and other adaptive phenotypes. Although most in vitro studies examine bacterial properties averaged over large populations, the levels of key molecular determinants of bacterial fitness and pathogenicity (e.g., oxygen, quorum-sensing signals) may vary over micrometer scales within small, dense cellular aggregates believed to play key roles in disease transmission. A detailed understanding of how cell-cell interactions contribute to pathogenicity in natural, complex environments will require a new level of control in constructing more relevant cellular models for assessing bacterial phenotypes. Here, we describe a microscopic three-dimensional (3D) printing strategy that enables multiple populations of bacteria to be organized within essentially any 3D geometry, including adjacent, nested, and free-floating colonies. In this laser-based lithographic technique, microscopic containers are formed around selected bacteria suspended in gelatin via focal cross-linking of polypeptide molecules. After excess reagent is removed, trapped bacteria are localized within sealed cavities formed by the cross-linked gelatin, a highly porous material that supports rapid growth of fully enclosed cellular populations and readily transmits numerous biologically active species, including polypeptides, antibiotics, and quorum-sensing signals. Using this approach, we show that a picoliter-volume aggregate of Staphylococcus aureus can display substantial resistance to ?-lactam antibiotics by enclosure within a shell composed of Pseudomonas aeruginosa. PMID:24101503

  1. 3D visualization of deformation structures and potential fluid pathways at the Grimsel Test Site

    NASA Astrophysics Data System (ADS)

    Schneeberger, Raphael; Kober, Florian; Berger, Alfons; Spillmann, Thomas; Herwegh, Marco

    2015-04-01

    Knowledge on the ability of fluids to infiltrate subsurface rocks is of major importance for underground constructions, geothermal or radioactive waste disposal projects. In this study, we focus on the characterization of water infiltration pathways, their 3D geometries and origins. Based on surface and subsurface mapping in combination with drill core data, we developed by the use of MoveTM (Midland Valley Exploration Ltd.) a 3D structural model of the Grimsel Test Site (GTS). GTS is an underground laboratory operated by NAGRA, the Swiss organisation responsible for the management of nuclear waste. It is located within a suite of post-Variscan magmatic bodies comprising former granitic and granodioritic melts, which are dissected by mafic and aplitic dikes. During Alpine orogeny, the suite was tectonically overprinted within two stages of ductile deformation (Wehrens et al., in prep.) followed by brittle overprint of some of the shear zones during the retrograde exhumation history. It is this brittle deformation, which controls today's water infiltration network. However, the associated fractures, cataclasites and fault gouges are controlled themselves by aforementioned pre-existing mechanical discontinuities, whose origin ranges back as far as to the magmatic stage. For example, two sets of vertically oriented mafic dikes (E-W and NW-SE striking) and compositional heterogeneities induced by magmatic segregation processes in the plutonic host rocks served as nucleation sites for Alpine strain localization. Subsequently, NE-SW, E-W and NW-SE striking ductile shear zones were formed, in combination with high temperature fracturing while dissecting the host rocks in a complex 3D pattern (Wehrens et al, in prep.). Whether the ductile shear zones have been subjected to brittle reactivation and can serve as infiltration pathways or not, depends strongly on their orientations with respect to the principal stress field. Especially where deformation structures intersect each other, water flow is high. Our 3D structural model allows the recognition of such intersections in 3D space and the prediction of their spatial extent. The structural model developed with the introduction of the locally known hydraulic permeabilities and in combination with the results of on-going hydrochemical investigations will allow to estimate the location of the recently active water pathways. References Wehrens, P., Baumberger, R., Berger, A., & Herwegh, M. (in prep.). How is strain localized in a mid-crustal basement section? Spatial distribution of deformation in the Aar massif (Switzerland).

  2. Experimental studies of magnetic reconnection in 3D geometries

    E-print Network

    Vrublevskis, Arturs

    2014-01-01

    Magnetic reconnection is an important and prevalent plasma physics phenomenon occurring in astrophysical (solar flares), space (magnetospheric substorms), and laboratory settings (tokamak sawtooth oscillations). It allows ...

  3. Stress channelling in extreme couple-stress materials Part II: Localized folding vs faulting of a continuum in single and cross geometries

    E-print Network

    Panos A. Gourgiotis; Davide Bigoni

    2015-09-23

    The antiplane strain Green's functions for an applied concentrated force and moment are obtained for Cosserat elastic solids with extr