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1

Improved 3D Modeling of Complex Fault Geometries Using Poly3D, an Elastic Boundary Element Code  

NASA Astrophysics Data System (ADS)

Recent advances in geologic mapping, aftershock location, and reflection seismology allow geoscientists to image surface and subsurface structures with greater precision. These images demonstrate that earthquake ruptures typically occur along faults or fault systems that display complex 3D geometries. Poly3D, a 3D boundary element code and user interface, enables the integration of these varied data sets to constrain fault geometry and accurately models the complex geometries, limited only by data precision and computing power. Poly3D is based on the analytical solution for the elastic boundary value problem of an angular dislocation in a half space composed of a homogeneous and isotropic linear-elastic material (Comninou & Dunders, 1975). One of the major advantages that Poly3D has over other commonly used dislocation models (e.g. based on Okada, 1985) is the use of a triangular rather than rectangular uniform dislocation patch. The triangular shape enables one to model complex 3D shapes without gaps or overlaps. A further advantage of Poly3D is the possibility of using remote strain boundary conditions to simulate tectonic deformation and traction boundary conditions to simulate stress drop on fault segments. Poly3D has been applied to numerous problems of fault interaction and earthquake deformation over the last 5 years. We present results from three recent studies that have focused on fault interaction and earthquake triggering using a variety of geologic and geophysical data sets to constrain fault geometries and deformation. 1) GPS field mapping of faults and deformed strata is used to investigate fault slip and fault interaction around a set of normal faults at Chimney Rock, Utah. 2) Large-scale geologic mapping and measured slip distributions are integrated with published geophysical data to study the interaction between the 1967 Mudurnu Valley and 1999 Kocaeli earthquakes in Turkey. 3) Aftershock triggering and the development of normal fault systems are investigated by integrating high-precision aftershock locations and published geological and geodetic data sets from the 1995 Kozani-Grevena earthquake in Greece. In each of these studies the geometric flexibility of Poly3D and the ability to integrate available data sets has led to new insights into the processes of faulting, fault interaction, and earthquake triggering.

Pollard, D.; Maerten, F.; Maerten, L.; Resor, P.; Muller, J.; Aydin, A.

2001-12-01

2

Relationship Between the 3-D Fault Geometry and Coseismic Displacements in the 1999 Chichi Earthquake, Taiwan  

NASA Astrophysics Data System (ADS)

The Mw 7.6 Chichi earthquake is perhaps the best instrumented major earthquake ever, with extensive geodetic, strong motion, broad-band and regional network data plus a well-studied 80-90 km long surface break of the Chelungpu fault with surface slip commonly reaching 3-6 m and locally 9 m. However up to now there has been no independently constrained detailed model of the fault geometry, which is unfortunate given the difficulties of simultaneously inverting for both geometry and slip. Here we present a detailed independently constrained fault model of this strongly 3-dimensional fault based on petroleum seismic, well and very detailed surface mapping. These data are able to strongly constrain the fault geometry in 3D only because of the fact that the Chelungpu fault is parallel to bedding in the hanging wall, running in the Chinshui Shale (the fault is thus everywhere parallel to bedding in the hanging wall). This leads to the unique opportunity of having a detailed and independently constrained fault map for a highly instrumented major earthquake. We find a very close relationship between details of the 3D fault geometry and details of the high-resolution geodetic displacements from GPS and satellite geodesy (Yu et al. 2001; Dominguez et al., in press). The most striking feature is that high vertical and horizontal displacements are concentrated directly above the fault ramp, with the displacement vectors parallel to km-scale grooves in the ramp surface. Furthermore above the fault ramp the ratio of vertical to horizontal displacement is in close agreement with the local tangent of fault dip in the azimuth of the slip vector. GPS data above the fault detachment show lower magnitude (~3 m) and small positive or negative vertical component, as expected. Finally the E-W zone of folding and faulting at the northern termination of the Chichi rupture is seen to correspond exactly to the crest of a transverse ramp in the footwall. Comparison with the seismic slip models of many groups is necessarily more qualitative because these models assume uniformly dipping ramps with no detachment, but they typically show high slip at shallow depths only near where the fault ramp exists. The base of the ramp in our fault model varies regionally between 3 and 7 km. The rupture initiation point is not on the Chelungpu fault but ~4 km deeper on a minor fault.

Yue, L.; Suppe, J.; Hung, J.

2002-12-01

3

Segmentation of the Calaveras-Hayward Fault System Based on 3-D Geometry and Geology at Large-Earthquake Depth  

Microsoft Academic Search

For the purpose of estimating seismic hazard, the Calaveras and Hayward Faults have been considered as separate structures and analyzed and segmented based largely on their surface-trace geometry and the extent of the 1868 Hayward Fault earthquake. Recent relocations of earthquakes and 3-D geologic mapping have shown, however, that at depths associated with large earthquakes (>5 km) the fault geology

R. W. Graymer; R. W. Simpson; R. C. Jachens; D. A. Ponce; G. A. Phelps; J. T. Watt; C. M. Wentworth

2007-01-01

4

3d Geometry of The North Anatolian Fault System In The Cinarcik Basin: Preliminary Results (seismarmara 2001)  

NASA Astrophysics Data System (ADS)

The North Anatolian Fault (NAF) has been responsible for the last two earthquakes in Turkey (Izmit and Duzse, 1999). To the west, a seismic gap exists in the Marmara Sea, which is formed as series of pull apart basins along the NAF. Initial bathymetry and seismic reflection profiles show the presence of several faults on various scales in the Marmara Sea, from a few kilometers to tens of kilometers, in the three pull apart basins. The stress field (Coulomb) study suggests the possibility of a large earth- quake in this area, which could have a devastating effect on the region and on Istanbul, which is located only 10 km from north of the northern branch of NAF. In order to understand the earthquake activities in the Marmara Sea and image major seismogenic faults at depth, a combined seismic reflection, refraction and earthquake experiment was carried. Half of the 4000 km of deep seismic reflection profiles were acquired as a very detailed 3D grid survey at 600 m line spacing in the Cinarcik Basin, where NAF enters the Marmara Sea and bifurcates into two strands. On-board raw stacks show the presence of active faults down to 10 km in the basin. The 3D data provides a detailed 3D geometry of the NAF fault system in the Cinarcik basin, which suggests that it is an active NW-SE trending a kite-tail shaped pull-apart basin, with the two known strands of the NAF as its the long limbs. The relationship between the sedimentary strata, the basement and the faults provides insight on the evolution of basin. The ex- tensive set of faults along the southern limb suggests that this limb has played a key role in the evolution of the basin, from east to west. A small pull-apart basin at the corner of two adjoining faults in the south-west shows the role of a change in stress regime. A complex fault system in the Cinarcik basin suggests that is not a classical pull-apart basin, like the central basin, but may be representative of a basin at the tip of a long strike-slip fault, such as NAF. The 3D results will be discussed in the light of the formation and evolution of the whole Marmara Sea.

Singh, S.; Hirn, A.; de Voogd, B.; Vigner, A.; Bazin, S.; Charvis, P.; Géli, L.; Saatcilar, R.; Taymaz, T.; Ozalaybey, S.; Cetin, S.; Oçakoglu, N.; Ricolleau, A.; Karakoç, F.; Selvigen, V.

5

Geometry in 3-D  

NSDL National Science Digital Library

This resource guide from the Middle School Portal 2 project, written specifically for teachers, provides links to exemplary resources including background information, lessons, career information, and related national science education standards. The online resources featured in Geometry in 3-D actively engage students in exploring a variety of geometric shapes, at times through lessons that involve building models or creating paper nets that fold into three-dimensional shapes; at other times, through technology that allows students to rotate and zoom in on figures, noting their attributes and complexity. Other lessons offer problems on surface area and volume, a part of every middle school curriculum. The problems, each with a different twist on the subject, challenge students to reconsider their understanding of how to measure solids. Activities for developing spatial sense, another primary objective in teaching geometry, are also featured. Finally, there are online galleries of geometric solids, included for the rare opportunity they offer to show your students the beauty in mathematics. In Background Information, you will find workshop sessions developed for teachers and other materials that may interest you as a professional. Each resource deals specifically with three-dimensional geometry topics that align with the geometry and measurement standards recommended by NCTM.

Herrera, Terese

2006-09-01

6

Intrinsic Regularity Detection in 3D Geometry  

Microsoft Academic Search

\\u000a Automatic detection of symmetries, regularity, and repetitive structures in 3D geometry is a fundamental problem in shape\\u000a analysis and pattern recognition with applications in computer vision and graphics. Especially challenging is to detect intrinsic regularity, where the repetitions are on an intrinsic grid, without any apparent Euclidean pattern to describe the shape,\\u000a but rising out of (near) isometric deformation of

Niloy J. Mitra; Alexander M. Bronstein; Michael M. Bronstein

2010-01-01

7

Imaging fault zones using 3D seismic image processing techniques  

NASA Astrophysics Data System (ADS)

Significant advances in structural analysis of deep water structure, salt tectonic and extensional rift basin come from the descriptions of fault system geometries imaged in 3D seismic data. However, even where seismic data are excellent, in most cases the trajectory of thrust faults is highly conjectural and still significant uncertainty exists as to the patterns of deformation that develop between the main faults segments, and even of the fault architectures themselves. Moreover structural interpretations that conventionally define faults by breaks and apparent offsets of seismic reflectors are commonly conditioned by a narrow range of theoretical models of fault behavior. For example, almost all interpretations of thrust geometries on seismic data rely on theoretical "end-member" behaviors where concepts as strain localization or multilayer mechanics are simply avoided. Yet analogue outcrop studies confirm that such descriptions are commonly unsatisfactory and incomplete. In order to fill these gaps and improve the 3D visualization of deformation in the subsurface, seismic attribute methods are developed here in conjunction with conventional mapping of reflector amplitudes (Marfurt & Chopra, 2007)). These signal processing techniques recently developed and applied especially by the oil industry use variations in the amplitude and phase of the seismic wavelet. These seismic attributes improve the signal interpretation and are calculated and applied to the entire 3D seismic dataset. In this contribution we will show 3D seismic examples of fault structures from gravity-driven deep-water thrust structures and extensional basin systems to indicate how 3D seismic image processing methods can not only build better the geometrical interpretations of the faults but also begin to map both strain and damage through amplitude/phase properties of the seismic signal. This is done by quantifying and delineating the short-range anomalies on the intensity of reflector amplitudes and collecting these into "disturbance geobodies". These seismic image processing methods represents a first efficient step toward a construction of a robust technique to investigate sub-seismic strain, mapping noisy deformed zones and displacement within subsurface geology (Dutzer et al.,2011; Iacopini et al.,2012). In all these cases, accurate fault interpretation is critical in applied geology to building a robust and reliable reservoir model, and is essential for further study of fault seal behavior, and reservoir compartmentalization. They are also fundamental for understanding how deformation localizes within sedimentary basins, including the processes associated with active seismogenetic faults and mega-thrust systems in subduction zones. Dutzer, JF, Basford., H., Purves., S. 2009, Investigating fault sealing potential through fault relative seismic volume analysis. Petroleum Geology Conference series 2010, 7:509-515; doi:10.1144/0070509 Marfurt, K.J., Chopra, S., 2007, Seismic attributes for prospect identification and reservoir characterization. SEG Geophysical development Iacopini, D., Butler, RWH. & Purves, S. (2012). 'Seismic imaging of thrust faults and structural damage: a visualization workflow for deepwater thrust belts'. First Break, vol 5, no. 30, pp. 39-46.

Iacopini, David; Butler, Rob; Purves, Steve

2013-04-01

8

3D Geometry Projection from 2D to 3D  

E-print Network

n n n zzz yyy xxx P Points = y x tsss tsss S 3,22,21,2 3,12,11,1 Some matrix = n n vvv uuu I 21 21 of the points in P. #12;5 First, look at 2D rotation (easier) - n n yyy xxx 21 21 ... cossin sincos coordinates. That is, it's rotated. #12;6 Simple 3D Rotation - n n n zzz yyy xxx 21 21 21 ... 100 0cossin 0

Jacobs, David

9

Texturing 3D Geometries Using Reaction Diffusion Hayden Devlin  

E-print Network

Texturing 3D Geometries Using Reaction Diffusion Hayden Devlin School of Computer Science automating the generation of organic surface textures for arbitrary 3D geometries. Reaction Diffusion the traditional system is adapted to achieve 2½D displacement texturing on the surface of any arbitrary 3D shape

Yao, Xin

10

Automatic visualization of 3D geometry contained in online databases  

NASA Astrophysics Data System (ADS)

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.

Zhang, Jie; John, Nigel W.

2003-04-01

11

3-D GEOMETRY ENHANCEMENT BY CONTOUR OPTIMIZATION IN TURNTABLE SEQUENCES  

E-print Network

, computer games, product presentations in e-commerce, or other virtual reality systems. Although the ren and design of 3-D models with high quality is still time consuming and thus expensive. This has motivated geometry. In order to circumvent the limitation of reconstructing the visual hull only, many extensions

Eisert, Peter

12

Wavelet-based multiple description coding of 3-D geometry  

NASA Astrophysics Data System (ADS)

In this work, we present a multiple description coding (MDC) scheme for reliable transmission of compressed three dimensional (3-D) meshes. It trades off reconstruction quality for error resilience to provide the best expected reconstruction of 3-D mesh at the decoder side. The proposed scheme is based on multiresolution geometry compression achieved by using wavelet transform and modified SPIHT algorithm. The trees of wavelet coefficients are divided into sets. Each description contains the coarsest level mesh and a number of tree sets coded with different rates. The original 3-D geometry can be reconstructed with acceptable quality from any received description. More descriptions provide better reconstruction quality. The proposed algorithm provides flexible number of descriptions and is optimized for varying packet loss rates (PLR) and channel bandwidth.

Norkin, Andrey; Bici, M. Oguz; Bozdagi Akar, Gozde; Gotchev, Atanas; Astola, Jaakko

2007-01-01

13

3D seismic characterisation of an array of blind normal faults in the Levant Basin, Eastern Mediterranean  

E-print Network

of throw distribution on the fault planes shows that the displacement exhibits a crudely concentric pattern The geometry, throw distribution and kinematics of an array of blind normal faults were investigated using a high resolution 3D seismic dataset located in the Levant Basin, offshore Israel, to establish criteria

Demouchy, Sylvie

14

Simulation of human ischemic stroke in realistic 3D geometry  

NASA Astrophysics Data System (ADS)

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.

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

2013-06-01

15

Visualization package for 3D laser-scanned geometry  

NASA Astrophysics Data System (ADS)

A computer software package named LEGO was designed and implemented to enable medical personnel to explore and manipulate laser scanned 3D geometry obtained from a Cyberware 4020PS scanner. This type of scanner reconstructs a real world object into a mathematical computer model by collecting thousands of depth measurement using a low powered laser. LEGO consists of a collection of tools that can be interactively combined to accomplish complex tasks. Tools fall into five major categories: viewing, simple, quantitative, manipulative, and miscellaneous. This paper is based on a masters thesis obtained from the University of Illinois at Chicago.

Neumann, Paul F.; Sadler, Lewis L.

1993-06-01

16

A linguistic geometry for 3D strategic planning  

NASA Technical Reports Server (NTRS)

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.

Stilman, Boris

1995-01-01

17

3D Fault Network of the Murchison Domain, Yilgarn Craton  

NASA Astrophysics Data System (ADS)

The architecture of Archean granite-greenstone terranes is often controlled by networks of 10 km to 100 km-scale shear zones that record displacement under amphibolite facies to greenschist facies metamorphic conditions. The geometry of such crustal scale 'fault networks' has been shown to be highly relevant to understand the tectonic and metamorphic history of granite-greenstone terranes, as well as the availability of structural controlled fluid pathways related to magmatic and hydrothermal mineralization. The Neoarchean Yilgarn Craton and the Proterozoic orogens around its margins constitute one of Earth's greatest mineral treasure troves, including iron, gold, copper and nickel mineral deposits. Whereas the Yilgarn Craton is one of the best studied Archean cratons, its enormous size and limited outcrop are detrimental to the better understanding of what controls the distribution of these vast resources and what geodynamic processes were involved the tectonic assembly of this part of the Australian continent. Here we present a network of the major faults of the NW Yilgarn Craton between the Yalgar Fault, Murchison's NW contact with the Narryer Terrane to the Ida Fault, its boundary with the Eastern Goldfields Superterrane. The model has been constructed from various geophysical and geological data, including potential field grids, Geological Survey of Western Australia map sheets, seismic reflection surveys and magnetotelluric traverses. The northern extremity of the modelled area is bounded by the Proterozoic cover and the southern limit has been arbitrarily chosen to include various greenstone belts. In the west, the major faults in the upper crust, such as the Carbar and Chundaloo Shear Zones, dip steeply towards the west and then flatten off at depth. They form complex branching fault systems that bound the greenstone belts in a series of stacked faults. East of the Ida, the far east of the model, the faults have been integrated with Geoscience Australia's pmd*CRC Eastern Goldfields model. In the central portion, the major faults such as the Youanmi and Wattle Creek, dip to the east and can be followed into the fabric of the Yarraquin Seismic Province. The Wattle Creek Shear Zone in particular can be traced on all three of the Youanmi seismic lines. The greenstones are cradled between these major faults and antithetic westward dipping subsidiary faults such as the Edale Shear Zone. While the Ida Fault cannot be located with great confidence, the slight drop in Moho depth toward the east and the overall change of seismic texture delineate the Youanmi-Eastern Goldfields boundary. The Lawler's Anticline, presumably located in the hanging wall of the Ida Fault, again changes the style of faulting with the Lawler's tonalite forming the core of a 10 km-scale antiform. The fault network presented here is a milestone to a craton-wide integrated structural model and will hopefully contribute to provide a better spatial context for geological, geochemical and geophysical data in our quest to understand the tectonics and mineral potential of the Yilgarn craton.

Murdie, Ruth; Gessner, Klaus

2014-05-01

18

3D Velocity Structure of Chukou Fault Area, Taiwan from Seismic Tomography  

NASA Astrophysics Data System (ADS)

In this study, we used the seismic data that recorded by the broadband stations which deployed around the Chukou fault area, Taiwan. We have chosen 1661 earthquake events with high quality records in this research. The waveform cross correlation technique is applied to calculate the 143086 pairs of waveform data. By combining with data from the seismic catalog, there are 342202 absolute travel-time pairs through the double difference tomography method to relocate the seismicity and invert the 3D velocity structures beneath the Chukou fault area. Due to Taiwan Island is located in an active boundary zone between the Eurasia continental and Philippine Sea plates, the violent collision between the two plates which causes a series of imbricate fold-thrust belts to form between the western foothills and the coastal plain. The Chukou fault is just the boundary between the fold-thrust belts and the coastal plain in the Chia-Nan area, Taiwan. The seismotectonic structure beneath this area is more complex. From many studies, velocity structure can be used as an indicator of the geometry of fault and the general aspect of tectonics. Therefore, the first goal of this research is to analyze the degree of correlation between the velocity structure and the characteristics of seismicity and the tectonic implications of the area. The second intention is to study the distribution of seismic events and its association with fault activities. Our results indicate that the variation of velocity structure beneath fault area is caused by local geological structures, complex fault crossing. We also find that most earthquakes occur in the area that has Vp/Vs gradient varying rapidly. Finally, both using catalog and cross-correlation data in the inversion procedure are not only exhibit better resolution, but also can obtain the detail 3D velocity structure beneath the fault zone.

Chen, C.; Chang, W.; Jian, W.

2009-12-01

19

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

SciTech Connect

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.

Neuhaus, D. (Petroleum Development Oman, Muscat (Oman))

1993-09-01

20

Multifunctional optical nanofiber polarization devices with 3D geometry.  

PubMed

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

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

2014-07-28

21

Preliminary Pseudo 3-D Imagery of the State Line Fault, Stewart Valley, Nevada Using Seismic Reflection Data  

NASA Astrophysics Data System (ADS)

The Pahrump Fault system is located in the central Basin and Range region and consists of three main fault zones: the Nopah range front fault zone, the State Line fault zone and the Spring Mountains range fault zone. The State Line fault zone is made up north-west trending dextral strike-slip faults that run parallel to the Nevada- California border. Previous geologic and geophysical studies conducted in and around Stewart Valley, located ~90 km from Las Vegas, Nevada, have constrained the location of the State Line fault zone to within a few kilometers. The goals of this project were to use seismic methods to definitively locate the northwestern most trace of the State Line fault and produce pseudo 3-D seismic cross-sections that can then be used to characterize the subsurface geometry and determine the slip of the State Line fault. During July 2007, four seismic lines were acquired in Stewart Valley: two normal and two parallel to the mapped traces of the State Line fault. Presented here are preliminary results from the two seismic lines acquired normal to the fault. These lines were acquired utilizing a 144-channel geode system with each of the 4.5 Hz vertical geophones set out at 5 m intervals to produce a 595 m long profile to the north and a 715 m long profile to the south. The vibroseis was programmed to produce an 8 s linear sweep from 20-160 Hz. These data returned excellent signal to noise and reveal subsurface lithology that will subsequently be used to resolve the subsurface geometry of the State Line fault. This knowledge will then enhance our understanding of the evolution of the State Line fault. Knowing how the State Line fault has evolved gives insight into the stick-slip fault evolution for the region and may improve understanding of how stress has been partitioned from larger strike-slip systems such as the San Andreas fault.

Saldaña, S. C.; Snelson, C. M.; Taylor, W. J.; Beachly, M.; Cox, C. M.; Davis, R.; Stropky, M.; Phillips, R.; Robins, C.; Cothrun, C.

2007-12-01

22

Connecting multi-scale fault geometry with field observations: insights into fluid-fault rock relations  

NASA Astrophysics Data System (ADS)

Fault geometry along with heterogenities in fluid pressure locally influences the mechanical behavior of faulting and the type of fault rock damage generated. The Naukluft Nappe Complex in central Namibia, southwest Africa features a well exposed basal foreland thrust fault emplaced during the 550 Ma Damara Orogen. Using differential GPS we walked and mapped the kilometer-scale dolomitic basal fault at two localities, the East and West side of the nappe complex. 3D fault geometry and orientation over each locality was interpolated using the high resolution GPS maps. The interpolated 3D geometry was then correlated with field observations of fault rock damage including cataclastic injection systems, brecciation, and alteration in the fault rock. 2D cross-sections were rendered using the interpolated 3D geometries. The eastern flank of the nappe complex locally exhibits ramp geometries and a prevalent granular fault rock known as "gritty dolomite". Cataclastic injection systems of gritty dolomite are observed injecting upsection off the basal thrust through opening mode fractures and are generally subvertical to the fault plane. The injectites are centimeter to meter scale, sometimes reach tens of meters in vertical extent, the width tapered towards the injection tip. Laminae interpreted as flow banding are oriented subparallel to the injectite walls and is also present in the basal thrust subparallel to the fault plane. Neocrystallized dolomite, quartz, and fracture filling calcite is observed within injectite systems suggesting the presence of super-saturated fluid. Bending strains create localized extension as the hanging wall enters the ramp, facilitating Mode I fractures and the formation of injectites which are observed at the base, within, and at the upper flat of the ramp structure, recording progressive hanging wall transport. Fault dip increases in the northern area of the eastern locality where a unit of shales directly overlies footwall limestone. The dolomitic fault rock, typically directly overlying the footwall is observed upsection. Injections propagate downsection off the dolomitic source bed and create a complex, discontinuous network of minor dikes and sills within the shale beds, likely exploiting bedding weaknesses. The basal thrust in the western side of the nappe complex is of consistent shallow dip with no evidence of ramp structures. The footwall is primarily shales with some discontinuous calc-mylonite and limestone lenses. At the basal thrust a yellow, altered dolomite grades upsection into massive grey dolomite. The hanging wall is composed of imbricate listric faults and folds of dolomite, quartzite, and shale layers. The alteration zone, along with the presence of footwall shales injecting upsection into the altered zone suggests a relative high fluid pressure in the footwall, consistent with the requirement for low angle overthrust sliding. We hypothesize that differing fault damage structures between the eastern and western localities on the basal thrust is the result of the relationship between local fault geometry and fluid pressure. Where the eastern basal thrust contained fluid within the granular fault rock, brecciation and injectites are common, and where the western locale had pore fluid within the footwall, an alteration zone is present along the fault with minor footwall injections.

Sherry, T. J.; Melosh, B. L.; Rowe, C. D.

2012-12-01

23

3D Fault modeling of the active Chittagong-Myanmar fold belt, Bangladesh  

NASA Astrophysics Data System (ADS)

The Chittagong-Myanmar fold belt (CMFB), located in eastern Bangladesh, eastern India and western Myanmar, accommodates east-west shortening at the India-Burma plate boundary. Oblique subduction of the Indian Plate beneath the Burma Plate since the Eocene has led to the development of a large accretionary prism complex, creating a series of north-south trending folds. A continuous sediment record from ~55 Ma to the present has been deposited in the Bengal Basin by the Ganges-Brahmaputra-Meghna rivers, providing an opportunity to learn about the history of tectonic deformation and activity in this fold-and-thrust belt. Surface mapping indicates that the fold-and-thrust belt is characterized by extensive N-S-trending anticlines and synclines in a belt ~150-200 km wide. Seismic reflection profiles from the Chittagong and Chittagong Hill Tracts, Bangladesh, indicate that the anticlines mapped at the surface narrow with depth and extend to ~3.0 seconds TWTT (two-way travel time), or ~6.0 km. The folds of Chittagong and Chittagong Hill Tracts are characterized by doubly plunging box-shaped en-echelon anticlines separated by wide synclines. The seismic data suggest that some of these anticlines are cored by thrust fault ramps that extend to a large-scale décollement that dips gently to the east. Other anticlines may be the result of detachment folding from the same décollement. The décollement likely deepens to the east and intersects with the northerly-trending, oblique-slip Kaladan fault. The CMFB region is bounded to the north by the north-dipping Dauki fault and the Shillong Plateau. The tectonic transition from a wide band of E-W shortening in the south to a narrow zone of N-S shortening along the Dauki fault is poorly understood. We integrate surface and subsurface datasets, including topography, geological maps, seismicity, and industry seismic reflection profiles, into a 3D modeling environment and construct initial 3D surfaces of the major faults in this region. These models will further our understanding of fault geometry and history of the CMFB, allowing us to investigate the region's potential for geologic hazards. At least twenty-five percent of the country of Bangladesh sits on top of this actively deforming region, which is home to more than 28 million people. The CMFB also extends offshore, meaning that a major thrusting event could induce a regional tsunami with little warning. Understanding the geometry of the region's underlying detachment as well as the location and ages of specific thrust faults is critical to assessing seismic hazards for this heavily populated area.

Peterson, D. E.; Hubbard, J.; Akhter, S. H.; Shamim, N.

2013-12-01

24

Lithological Controls on 3D Fold Geometry in Mechanically Layered Rocks  

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

25

Geologic character of fault geometry and deformation of the Wildcat Fault, Berkeley, California  

NASA Astrophysics Data System (ADS)

In our analog study of fault hydrology, we use an interdisciplinary approach to investigate fault geology and its effects on regional hydrology. The study area is along the Wildcat Fault, a right-lateral strike-slip fault that is a splay of the Hayward Fault, which extends along the west side of the Berkeley Hills, California. Geologic mapping suggests that the Wildcat Fault here mainly separates the Miocene Claremont Formation composed of shale and cherts, and the Miocene-Pliocene Orinda Formation/San Pablo Group, composed of conglomerate, sandstone, and siltstone. We excavated several trenches to expose bedrock; we acquired seismic reflection and electrical resistivity data and three vertical boreholes and one inclined borehole cored across the Wildcat Fault. Trenching and coring indicate that the geology is more complex than the surface mapping indicates, especially along the contact between the Claremont Formation and Orinda Formation/San Pablo Group. In trench exposures, we mapped several zones of fault gouge that marked the contact between chert and siltstone, sandstone and siltstone, and chert and chert. At depths <150 m subsurface, we saw more than thirty zones of breccia and gouge, and two zones of cataclasite. Cores from vertical boring show a lithological dominance of Claremont Formation. We suggest that the Wildcat Fault in this area contains multiple shear zones in a zone of deformation at least 150 m wide. We have built a 3D geologic model to show the geometry of fault strands associated with the Wildcat Fault. The influence of fault gouge, breccia and cataclasite on the hydrology of the Wildcat Fault zone, slug, injection, and pumping tests in boreholes are reported by Karasaki et al. in a companion paper.

Onishi, C. T.; Karasaki, K.; Goto, J.; Moriya, T.; Ueta, K.; Tanaka, S.; Hamada, T.; Ito, H.; Tsukuda, K.

2010-12-01

26

Geometry and Photometry in 3D Visual Recognition  

E-print Network

The report addresses the problem of visual recognition under two sources of variability: geometric and photometric. The geometric deals with the relation between 3D objects and their views under orthographic and ...

Shashua, Amnon

1992-11-01

27

Geometry videos : a new representation for 3D animations  

E-print Network

Animations of three-dimensional computer graphics are becoming an increasingly prevalent medium for communication. There are many sources of 3D animations including physical simulations, scientific visualizations, and ...

Briceño Pulido, Héctor Manuel, 1974-

2003-01-01

28

On the Differential Geometry of 3D Flow Patterns: Generalized Helicoids and Diffusion MRI Analysis  

E-print Network

On the Differential Geometry of 3D Flow Patterns: Generalized Helicoids and Diffusion MRI Analysis in diffusion MRI [3], texture patterns on surfaces [13], hair patterns [6], and 3D streamlines [26]. Whereas of representations can be used to model the diffusion at a given location. While the early methods impose a 3D

Siddiqi, Kaleem

29

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

E-print Network

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

Kassegne, Samuel Kinde

30

Investigating 3D Geometry of Porous Media from High Resolution Images  

E-print Network

Investigating 3D Geometry of Porous Media from High Resolution Images W. B. Lindquist and A im­ age. 2 Image Segmentation CAT and LSCM images of porous media are grey scale im­ ages, usually of the Earth MS No.: SE39.2­012 First author: Lindquist 1 Investigating 3D Geometry of Porous Media from High

New York at Stoney Brook, State University of

31

3D microstructural and microchemical characteristics of SAFOD fault gouge: implications for understanding fault creep  

NASA Astrophysics Data System (ADS)

Fault creep on the SAFOD section of the San Andreas Fault occurs along mechanically weak fault gouge characterized by high proportions of hydrous clay minerals, namely smectite, illite-smectite and chlorite-smectite phases. These minerals are concentrated along closely spaced, interconnected polished slip surfaces that give the gouge its characteristic scaly fabric. Although it is generally accepted that the creep behavior of the gouge relates to the concentration of these minerals, the precise mechanisms by which clay minerals weaken rock is currently a topic of debate. In this contribution we present the first results from a "slice-and-view" study of SAFOD gouge material by focused ion beam - scanning electron microscopy (Zeiss Auriga FIB/SEM), which allows the reconstruction of the microstructure and microchemistry of mineralized slip surfaces in 3D. The core and cuttings samples studied were selected from ca. 3297 m measured depth and represent some of the weakest materials yet recovered from the borehole, with a frictional coefficient of ca. 0.10 and a healing rate close to zero. This gouge contains abundant serpentine and smectite minerals, the latter of which was identified by X-ray diffraction to be saponite, after Mg- and glycol intercalation. Imaging and chemical analyses reveal nanometer scale thin alteration seams of saponite clay distributed throughout the ca. 50 micron thick sheared serpentinite layer that coats the slip surfaces. The base of this layer is defined by cataclastically deformed iron oxide minerals. The 3D fabric implies the orientation of the hydrated smectite minerals, which are interconnected and lie commonly sub parallel to the slip surface, are responsible for the gouge creep behavior in the laboratory. These minerals, and related interlayered varieties, are particularly weak due to their thin particle size and large quantities of adsorbed water, properties that are expected to persist down to mid-crustal depth (ca. 10 km). Creep of the San Andres Fault at Parkfield can therefore be adequately explained by the nature and abundance of smectite lattice layers that provide a nanometer-scale control on the mechanisms of fault behavior.

Warr, Laurence; Wojatschke, Jasmaria; Carpenter, Brett; Marone, Chris; Schleicher, Anja; van der Pluijm, Ben

2013-04-01

32

Software-based geometry operations for 3D computer graphics  

NASA Astrophysics Data System (ADS)

In order to support a broad dynamic range and a high degree of precision, many of 3D renderings fundamental algorithms have been traditionally performed in floating-point. However, fixed-point data representation is preferable over floating-point representation in graphics applications on embedded devices where performance is of paramount importance, while the dynamic range and precision requirements are limited due to the small display sizes (current PDA's are 640 × 480 (VGA), while cell-phones are even smaller). In this paper we analyze the efficiency of a CORDIC-augmented Sandbridge processor when implementing a vertex processor in software using fixed-point arithmetic. A CORDIC-based solution for vertex processing exhibits a number of advantages over classical Multiply-and-Acumulate solutions. First, since a single primitive is used to describe the computation, the code can easily be vectorized and multithreaded, and thus fits the major Sandbridge architectural features. Second, since a CORDIC iteration consists of only a shift operation followed by an addition, the computation may be deeply pipelined. Initially, we outline the Sandbridge architecture extension which encompasses a CORDIC functional unit and the associated instructions. Then, we consider rigid-body rotation, lighting, exponentiation, vector normalization, and perspective division (which are some of the most important data-intensive 3D graphics kernels) and propose a scheme to implement them on the CORDIC-augmented Sandbridge processor. Preliminary results indicate that the performance improvement within the extended instruction set ranges from 3× to 10× (with the exception of rigid body rotation).

Sima, Mihai; Iancu, Daniel; Glossner, John; Schulte, Michael; Mamidi, Suman

2006-02-01

33

Application of neural networks for identification of faults in a 3D seismic survey offshore Tunisia  

NASA Astrophysics Data System (ADS)

The Kerkennah High area (offshore Tunisia) is dominated by series of horst and grabens resulting from multiple tectonic events and multiphase stress (extension, compression, translation). In order to decipher this complex structural history from a 3D seismic survey, a neural network is applied to extract a fault-cube from the amplitude data (which does not image faults directly). The neural network transforms seismic attributes into a new 3D data cube in which faults are highlighted. This technique comprises the following steps. First, we compute several seismic attributes (dip-steering similarity, curvature, frequency, ridge and fault enhancement filters…) that enhance different aspects of the seismic data related to faulting. In a second step, a number of points in the seismic data are selected as representative of either faults or areas devoid of faults. These points are tested by the artificial neural network to determine the range in which the different attributes are representative of faults or not. Based on this learning phase, the neural network is then applied to the entire 3D seismic cube to produce a fault-cube that contains only faults which contrast and continuity have been enhance.

Mastouri, Raja; Marchant, Robin; Marillier, François; Jaboyedoff, Michel; Bouaziz, Samir

2013-04-01

34

Modeling the effects of 3-D slab geometry and oblique subduction on subduction zone thermal structure  

NASA Astrophysics Data System (ADS)

In this study, we revisit the effects of along-strike variation in slab geometry and oblique subduction on subduction zone thermal structures. Along-strike variations in slab dip cause changes in the descending rate of the slab and generate trench-parallel pressure gradients that drive trench-parallel mantle flow (e.g., Kneller and van Keken, 2007). Oblique subduction also drives trench-parallel mantle flow. In this study, we use a finite element code PGCtherm3D and examine a range of generic subduction geometries and parameters to investigate the effects of the above two factors. This exercise is part of foundational work towards developing detailed 3-D thermal models for NE Japan, Nankai, and Cascadia to better constrain their 3-D thermal structures and to understand the role of temperature in controlling metamorphic, seismogenic, and volcanic processes. The 3-D geometry of the subducting slabs in the forearc and arc regions are well delineated at these three subduction zones. Further, relatively large compilations of surface heat flow data at these subduction zones make them excellent candidates for this study. At NE Japan, a megathrust earthquake occurred on March 11, 2011; at Nankai and Cascadia, there has been a great effort to constrain the scale of the next subduction thrust earthquake for the purpose of disaster prevention. Temperature influences the slip behavior of subduction faults by (1) affecting the rheology of the interface material and (2) controlling dehydration reactions, which can lead to elevated pore fluid pressure. Beyond the depths of subduction thrust earthquakes, the thermal structure is affected strongly by the pattern of mantle wedge flow. This flow is driven by viscous coupling between the subducting slab and the overriding mantle, and it brings in hot flowing mantle into the wedge. The trench-ward (up-dip) extent of the slab-mantle coupling is thus a key factor that controls the thermal structure. Slab-mantle decoupling at shallow depths causes mantle stagnation and a cool condition, which allows serpentinization to occur, whereas coupling at greater depths drives hot flowing mantle, providing the thermal condition required for melt generation in the mantle wedge. The flowing mantle also causes rapid heating of the subducting slab and affects the occurrence of intraslab earthquakes. In the generic model calculations in the study, we also investigate the effect of local fluctuations in the depth of decoupling-coupling transition on the 3-D mantle wedge flow pattern and thermal structure. Kneller, E.A., and P.E. van Keken (2008), Effect of three-dimensional slab geometry on deformation in the mantle wedge: Implications for shear wave anisotropy, Geochem. Geophys. Geosyst., 9, Q01003, doi:10.1029/2007GC001677.

Wada, I.; Wang, K.; He, J.

2013-12-01

35

3-D Discrete Element Simulation of Strike Slip Faulting  

Microsoft Academic Search

Recent progress of the X-ray Computed Tomography(X-rayCT) enables us to observe not only the surface but also the inside of geomaterials with a certain level of resolution. X-rayCT was employed in a series of experiments on sand box to visualize the faulting mechanism. A three-dimensional discrete element simulation was performed in order to figure out not only the strain distribution

H. Saomoto; M. Yoshimi; S. Kunimatsu

2004-01-01

36

Verification of internal flow analyses in complex 3-D geometries  

NASA Astrophysics Data System (ADS)

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.

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

1992-11-01

37

The 2D-to-3D geometry hopping in small boron clusters: The charge effect  

NASA Astrophysics Data System (ADS)

DFT TPSSh/6-311+G(d) calculations are carried out on a series of 2D and 3D forms of Bn, n = 20, 22 and 24 in different charge states. For a certain size, the relative energy within a pair of two-dimensional quasi-planar (2D) and three-dimensional staggered double-ring (3D) boron cluster isomers may shift the sign as they reach a certain charge state. Specifically, electron addition tends to enhance the stability of the 2D over the corresponding 3D isomer irrespective of the available electrons. Linear correlations between 2D-3D relative energy and net charge are established. Along with 2D-to-3D geometry hopping at critical size, our results suggest a local 2D-3D geometry hopping via critical charge.

Pham, Hung Tan; Duong, Long Van; Pham, Buu Quoc; Nguyen, Minh Tho

2013-07-01

38

Combining recognition and geometry for data-driven 3D reconstruction  

E-print Network

Today's multi-view 3D reconstruction techniques rely almost exclusively on depth cues that come from multiple view geometry. While these cues can be used to produce highly accurate reconstructions, the resulting point ...

Owens, Andrew (Andrew Hale)

2013-01-01

39

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

E-print Network

The primary focus of this thesis is to present a framework to develop higher order global differentiability local approximations for 2-D and 3-D distorted element geometries. The necessity and superiority of higher order global differentiability...

Maduri, Rajesh Kumar

2008-02-01

40

Deformation around bends and stepovers of intracontinental strike-slip faults: Results of 3-D numerical modeling  

NASA Astrophysics Data System (ADS)

Bends and stepovers of strike slip faults are where transpressive mountain ranges or transtenstional basins are formed, and they are often the sites of termination, sometimes nucleation, of earthquake fault ruptures. Using a three-dimensional (3-D) visco-elasto-plastic finite element model, we are systematically investigating the 3-D stress fields and strain partitioning around bends and stopovers to better understand lithospheric deformation around these important geological features. We started with simplified stopovers and bends to illustrate the basic mechanics. For compressive stopovers, high shear stress is concentrated in the gap region, between the strike-slip faults. When the gap is wide (>75 km), plastic strain is localized in two narrow belts extending from the tips of the faults, indicating that the stepover may develop into subparallel faults. When the gap is narrow (<50 km), high plastic strain is localized between the gap, favoring formation of connecting faults and restraining bends. For dilatational stopovers, strain is localized in the gap region even when the gap is up to 100 km wide, hence wide releasing bends and pull-apart basins can be expected. When the connecting faults form to turn stopovers into bends, they generally enhance strain localization around the bends. The stress field and strain patterns around restraining bends and releasing bends vary with the geometry of the bends. In general, high shear stress is found in a broad band across the restraining bends, and strain is localized in two belts extending from the ends of the bend and sub-parallel to the strike-slip faults. For releasing bends, shear stress is generally low across the bends, strain can be localized within the bend with the effect of straightening the bends, and subsidence is often asymmetric. Applying these models to the Big Bend (a restraining bend) and the Salton Trough (a releasing bend), we show that the model results are generally consistent with observations.

Liu, M.; Wang, H.

2012-12-01

41

Fractal geometry in the San Andreas fault system  

Microsoft Academic Search

It has been noted that the spatial distribution of earthquakes and the mode of strain release in the San Andreas fault system is related to the complexity of fault geometry. Because of their rough appearance over many length scales, faults can be regarded as fractal surfaces. Direct estimates of fractal dimension D of portions of the San Andreas fault system

Paul G. Okubo; Keiiti Aki

1987-01-01

42

3D modeling of earthquake cycles of the Xianshuihe fault, southwestern China  

NASA Astrophysics Data System (ADS)

We perform 3D modeling of earthquake generation of the Xianshuihe fault, southwestern China, which is a highly active strike-slip fault with a length of about 350 km, in order to understand earthquake cycles and segmentations for a long-term forecasting and earthquake nucleation process for a short-term forecasting. Historical earthquake data over the last 300 years indicates repeated periods of seismic activity, and migration of large earthquake along the fault during active seismic periods. To develop the 3D model of earthquake cycles along the Xianshuihe fault, we use a rate- and state-dependent friction law. After analyzing the result, we find that the earthquakes occur in the reoccurrence intervals of 400-500 years. Simulation result of slip velocity distribution along the fault at the depth of 10 km during 2694 years along the Xianshuihe fault indicates that since the third earthquake cycle, the fault has been divided into 3 parts. Some earthquake ruptures terminate at the bending part of the fault line, which may means the shape of the fault line controls how earthquake ruptures. The change of slip velocity and displacement at 10 km depth is more tremendous than the change of the shallow and deep part of the fault and the largest slip velocity occurs at the depth of 10 km which is the exact depth of the seismic zone where fast rupture occurs.

Li, Xiao-Fan; Shibazaki, Bunichiro

2014-12-01

43

3D radiation transport benchmark problems and results for simple geometries with void region  

Microsoft Academic Search

Three-dimensional (3D) transport benchmark problems for simple geometries with void region were proposed at the OECD\\/NEA in order to check the accuracy of deterministic 3D transport programs. The exact total fluxes by the analytical method are given for the pure absorber cases, and Monte Carlo values are given for the 50% scattering cases as the reference values. The total fluxes

Yasunobu Nagaya; Naoki Sugimura

2001-01-01

44

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

SciTech Connect

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.

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

2000-06-01

45

Uncertainty assessment of imaging techniques for the 3D reconstruction of stent geometry.  

PubMed

This paper presents a quantitative assessment of uncertainty for the 3D reconstruction of stents. This study investigates a CP stent (Numed, USA) used in congenital heart disease applications with a focus on the variance in measurements of stent geometry. The stent was mounted on a model of patient implantation site geometry, reconstructed from magnetic resonance images, and imaged using micro-computed tomography (CT), conventional CT, biplane fluoroscopy and optical stereo-photogrammetry. Image data were post-processed to retrieve the 3D stent geometry. Stent strut length, separation angle and cell asymmetry were derived and repeatability was assessed for each technique along with variation in relation to ?CT data, assumed to represent the gold standard. The results demonstrate the performance of biplanar reconstruction methods is comparable with volumetric CT scans in evaluating 3D stent geometry. Uncertainty on the evaluation of strut length, separation angle and cell asymmetry using biplanar fluoroscopy is of the order ±0.2mm, 3° and 0.03, respectively. These results support the use of biplanar fluoroscopy for in vivo measurement of 3D stent geometry and provide quantitative assessment of uncertainty in the measurement of geometric parameters. PMID:24894028

Cosentino, Daria; Zwierzak, Iwona; Schievano, Silvia; Díaz-Zuccarini, Vanessa; Fenner, John W; Narracott, Andrew J

2014-08-01

46

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

E-print Network

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

Nicolas, Chamot-Rooke

47

Affine-invariant diffusion geometry for the analysis of deformable 3D shapes Dept. of Computer Science  

E-print Network

Affine-invariant diffusion geometry for the analysis of deformable 3D shapes Dan Raviv Dept in a specific application. In this paper, we construct (equi-)affine-invariant diffu- sion geometry for 3D shapes. Affine invariance is impor- tant in many applications in the analysis of images [12] and 3D

Kimmel, Ron

48

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

E-print Network

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

Hua, Jing

49

Statistical mechanics of the 3D axisymmetric Euler equations in a Taylor-Couette geometry  

E-print Network

Statistical mechanics of the 3D axisymmetric Euler equations in a Taylor-Couette geometry Simon ? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3 Statistical mechanics of a simplified problem without helical correla- tions 9 3.1 Definition of the simplified problem . . . . . . . . . . . . . . . . . . . . . . 9 3.2 Statistical mechanics of the toroidal

Paris-Sud XI, Université de

50

3D numerical modelling of underground excavations in a faulted rock mass using the Boundary Elements Method (BEM)  

E-print Network

2000-51 3D numerical modelling of underground excavations in a faulted rock mass using the Boundary : This paper presents a 3D-numerical modelling technique for underground excavations in a faulted rock mass (distincts elements) and CESAR (finites elements). Case study involving a coal mining panel excavation

Paris-Sud XI, Université de

51

Fault geometry and fault-zone development in mixed carbonate/clastic successions: Implications for reservoir management  

E-print Network

Fault geometry and fault-zone development in mixed carbonate/clastic successions: Implications Geological Survey) & David Richardson (Kier Mining) Overview Faults are key controlling elements of fluid flow within reservoirs. When faults undergo displacement, they change their fluid transmissibility

Stell, John

52

Pincushion correction techniques and their effects on calculated 3D positions and imaging geometries  

NASA Astrophysics Data System (ADS)

Two techniques for pincushion correction are evaluated based on their effect on calculation of the image geometry and 3D positions of object points. Images of a uniform wire mesh and a calibration phantom containing lead beads in its surface were acquired on the image intensifier TV systems in our catheterization labs. The radial mapping functions relating points in the original images and in the corrected images were determined using the mesh image. The undistorted mesh model was also used to determine and correct the distortions locally, i.e., for each square region between the mesh points. Thus, two corrected images were obtained. Images of the calibration phantom before and after correction were analyzed to determine the 3D position of the lead beads and the imaging geometry, using a calibration algorithm and the enhanced Metz-Fencil technique. In comparing the 3D positions calculated from the radially corrected and locally corrected images, the calculated 3D positions using the calibration technique vary by less than 0.6 mm in the x and y direction and less than 5.0 mm in the z direction. The uncorrected data yields differences of over 1 cm in the z direction. The 3D positions calculated using the enhanced Metz-Fencil technique appear to be more accurate when pincushion correction is applied.

Hoffmann, Kenneth R.; Chen, Yang; Esthappan, Jacqueline; Chen, Shiuh-Yung J.; Carroll, John D.

1996-04-01

53

High Resolution 3D Seismic Reflection Imaging Across the Northern Alpine Fault, New Zealand  

NASA Astrophysics Data System (ADS)

The Alpine Fault is a major transform structure that delineates the boundary between the Australian and Pacific plates through the South Island of New Zealand. Geological evidence suggests that ~470 km of dextral strike-slip movement has occurred along its length. Although it has not been affected by major ruptures during the 150 years of recorded history, large earthquakes (magnitude >7.5) have the potential to cause significant damage in inhabited regions. At our study site, the northern section of the fault juxtaposes Haast schist against west-coast sedimentary basement rocks. Recent lateral and smaller dip-slip components of movement are indicated by offset Quaternary river terraces at the site, and ground-penetrating radar data image a steeply dipping fault zone in the shallow subsurface (<15 m depth). The dip and fault structure at greater depths is uncertain. We have conducted a high-resolution 3D seismic reflection survey to image fault zone structure beyond the sedimentary cover into basement rock to ~200 m depth. An area of roughly 184 x 500 m was surveyed using a pseudo-3D shooting configuration that yielded ~50-fold data at a 4 x 2 m spacing. In addition, we recorded a 370 m-long ultra-high resolution seismic reflection line that provided ~60-fold data at 0.25 m intervals. Application of relatively standard seismic reflection processing techniques has yielded high-quality stacked sections that reveal sedimentary layering in shallow river gravels and a strong reflection from the sediment-basement contact. The dipping basement reflection is offset by ~40 m across the main trace of the Alpine fault. We speculate that basement faulting has offset an erosional surface that formed during the most recent major period of glaciation. Such an interpretation results in a Quaternary dip-slip rate in accord with other estimates along the fault in this region. A second basement discontinuity suggests the existence of a subsidiary fault strand approximately 300 m from the main fault.. We intend to employ more sophisticated processing techniques in an attempt to image more steeply dipping structures within the fault zone.

Kaiser, A.; Campbell, F.; Stratford, W.; Horstmeyer, H.; Langridge, R.; Finnemore, M.; Ernst, J.; Nobes, D.; Green, A.

2007-12-01

54

Massive sediment underthrusting beneath the Nankai Trough splay fault inferred from 3D seismic reflection data  

Microsoft Academic Search

In April-May 2006, we acquired a 3D seismic reflection data volume across the Nankai Trough and Kumano forearc basin to image the mega-splay fault system that lies along this segment of the Nankai Trough subduction zone. These data were acquired by Petroleum GeoServices (PGS) using 4 streamers, each 4,500 m long, and a 3090 m3 source, and cover an area

N. L. Bangs; G. F. Moore; E. M. Pangborn; S. P. Gulick; H. Tobin; A. Taira; S. Kuramoto

2004-01-01

55

Massive sediment underthrusting beneath the Nankai Trough splay fault inferred from 3D seismic reflection data  

Microsoft Academic Search

In April-May 2006, we acquired a 3D seismic reflection data volume across the Nankai Trough and Kumano forearc basin to image the mega-splay fault system that lies along this segment of the Nankai Trough subduction zone. These data were acquired by Petroleum GeoServices (PGS) using 4 streamers, each 4,500 m long, and a 3090 m3 source, and cover an area

N. L. Bangs; G. F. Moore; E. M. Pangborn; S. P. Gulick; H. Tobin; A. Taira; S. Kuramoto

2007-01-01

56

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

NASA Astrophysics Data System (ADS)

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.

Aldiss, Don; Haslam, Richard

2013-04-01

57

Statistical mechanics of the 3D axisymmetric Euler equations in a Taylor-Couette geometry  

NASA Astrophysics Data System (ADS)

In the present paper, microcanonical measures for the dynamics of three dimensional (3D) axially symmetric turbulent flows with swirl in a Taylor-Couette geometry are defined, using an analogy with a long range lattice model. We compute the relevant physical quantities and argue that two kinds of equilibrium regime exist, depending on the value of the total kinetic energy. For low energies, the equilibrium flow consists of a purely swirling flow whose toroidal profile depends on the radial coordinate only. For high energies, the typical toroidal field is uniform, while the typical poloidal field is organized into either a single vertical jet or a large scale dipole, and exhibits infinite fluctuations. This unusual phase diagram comes from the poloidal fluctuations not being bounded for the axisymmetric Euler dynamics, even though the latter conserve infinitely many ‘Casimir invariants’. This shows that 3D axially symmetric flows can be considered as intermediate between 2D and 3D flows.

Thalabard, Simon; Dubrulle, Bérengère; Bouchet, Freddy

2014-01-01

58

Quantitative analysis of 3D mitral complex geometry using support vector machines.  

PubMed

Quantitative analysis of 3D mitral complex geometry is crucial for a better understanding of its dysfunction. This work aims to characterize the geometry of the mitral complex and utilize a support-vector-machine-based classifier from geometric parameters to support the diagnosis of congenital mitral regurgitation (MR). The method has the following steps: (1) description of the 3D geometry of the mitral complex and establishment of its local reference coordinate system, (2) calculation of geometric parameters and (3) analysis and classification of these parameters. With a control group of 20 normal young children (11 boys, 9 girls, mean age 5.96 ± 3.12 years) and with the normal structure of mitral apparatus, 20 patients (9 boys, 11 girls, mean age 5.59 ± 3.30 years) suffering from severe congenital MR are studied in this study. The average classification accuracy is up to 90.0% of the present population, with the possibility of exploring quantitative association between the mitral complex geometry and the mechanism of congenital MR. PMID:22735308

Song, Wei; Yang, Xin; Sun, Kun

2012-07-01

59

3D simulation of near-fault strong ground motion: comparison between surface rupture fault and buried fault  

Microsoft Academic Search

In this paper, near-fault strong ground motions caused by a surface rupture fault (SRF) and a buried fault (BF) are numerically\\u000a simulated and compared by using a time-space-decoupled, explicit finite element method combined with a multi-transmitting\\u000a formula (MTF) of an artificial boundary. Prior to the comparison, verification of the explicit element method and the MTF\\u000a is conducted. The comparison results

Qifang Liu; Yifan Yuan; Xing Jin

2007-01-01

60

Fault geometry, rupture dynamics and ground motion from potential earthquakes on the North Anatolian Fault under the Sea of Marmara  

NASA Astrophysics Data System (ADS)

Using the 3-D finite-element method, we develop dynamic spontaneous rupture models of earthquakes on the North Anatolian Fault system in the Sea of Marmara, Turkey, considering the geometrical complexity of the fault system in this region. We find that the earthquake size, rupture propagation pattern and ground motion all strongly depend on the interplay between the initial (static) regional pre-stress field and the dynamic stress field radiated by the propagating rupture. By testing several nucleation locations, we observe that those far from an oblique normal fault stepover segment (near Istanbul) lead to large through-going rupture on the entire fault system, whereas nucleation locations closer to the stepover segment tend to produce ruptures that die out in the stepover. However, this pattern can change drastically with only a 10° rotation of the regional stress field. Our simulations also reveal that while dynamic unclamping near fault bends can produce a new mode of supershear rupture propagation, this unclamping has a much smaller effect on the speed of the peak in slip velocity along the fault. Finally, we find that the complex fault geometry leads to a very complex and asymmetric pattern of near-fault ground motion, including greatly amplified ground motion on the insides of fault bends. The ground-motion pattern can change significantly with different hypocentres, even beyond the typical effects of directivity. The results of this study may have implications for seismic hazard in this region, for the dynamics and ground motion of geometrically complex faults, and for the interpretation of kinematic inverse rupture models.

Oglesby, David D.; Mai, P. Martin

2012-03-01

61

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

NASA Astrophysics Data System (ADS)

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.

Dvoynishnikov, Sergey

2014-08-01

62

Color constancy using 3D scene geometry derived from a single image.  

PubMed

The aim of color constancy is to remove the effect of the color of the light source. As color constancy is inherently an ill-posed problem, most of the existing color constancy algorithms are based on specific imaging assumptions (e.g., gray-world and white patch assumption). In this paper, 3D geometry models are used to determine which color constancy method to use for the different geometrical regions (depth/layer) found in images. The aim is to classify images into stages (rough 3D geometry models). According to stage models, images are divided into stage regions using hard and soft segmentation. After that, the best color constancy methods are selected for each geometry depth. To this end, we propose a method to combine color constancy algorithms by investigating the relation between depth, local image statistics, and color constancy. Image statistics are then exploited per depth to select the proper color constancy method. Our approach opens the possibility to estimate multiple illuminations by distinguishing nearby light source from distant illuminations. Experiments on state-of-the-art data sets show that the proposed algorithm outperforms state-of-the-art single color constancy algorithms with an improvement of almost 50% of median angular error. When using a perfect classifier (i.e, all of the test images are correctly classified into stages); the performance of the proposed method achieves an improvement of 52% of the median angular error compared with the best-performing single color constancy algorithm. PMID:25051548

Elfiky, Noha; Gevers, Theo; Gijsenij, Arjan; Gonzalez, Jordi

2014-09-01

63

The mechanics of lubricated faults: Insights from 3-D numerical models  

NASA Astrophysics Data System (ADS)

The weakening mechanisms occurring during an earthquake failure are of prominent importance in determining the resulting energy release and the seismic waves excitation. In this paper we consider the fully dynamic response of a seismogenic structure where lubrication processes take place. In particular, we numerically model the spontaneous propagation of a 3-D rupture in a fault zone where the frictional resistance is controlled by the properties of a low viscosity slurry, formed by gouge particles and fluids. This model allows for the description of the fault motion in the extreme case of vanishing effective normal stress, by considering a viscous fault response and therefore without the need to invoke, in the framework of Coulomb friction, the generation of the tensile mode of fracture. We explore the effects of the parameters controlling the resulting governing law for such a lubricated fault; the viscosity of the slurry, the roughness of the fault surfaces and the thickness of the slurry film. Our results indicate that lubricated faults produce a nearly complete stress drop (i.e., a very low residual friction coefficient; ? ˜ 0.01), a high fracture energy density (EG ˜ few 10s of MJ/m2) and significant slip velocities (vpeak ˜ few 10s of m/s). The resulting values of the equivalent characteristic slip-weakening distance (d0eq = 0.1-0.8 m, depending on the adopted parameters) are compatible with the seismological inferences. Moreover, in the framework of our model we found that supershear ruptures are highly favored. In the case of enlarging gap height we can have the healing of slip or even the inhibition of the rupture. Quantitative comparisons with different weakening mechanisms previously proposed in the literature, such as the exponential weakening and the frictional melting, are also discussed.

Bizzarri, Andrea

2012-05-01

64

3-D Geometry-Based Statistical Modeling of Cross-Polarization Discrimination in Wireless Communication Channels  

Microsoft Academic Search

A new three-dimensional (3-D) geometry-based reference model for cross-polarization discrimination (XPD) in narrow-band fixed-to-fixed (F-to-F) or fixed-to-mobile (F-to-M) wireless channels is proposed. The proposed model is based on the superposition of polarization components on conservation-of-polarization planes (CoP-planes). This novel approach is used to derive the XPD at each distance without the aid of measurement data or its approximation. To the

Seok-Chul Kwon; Gordon L. Stüber

2010-01-01

65

CasimirSim - A Tool to Compute Casimir Polder Forces for Nontrivial 3D Geometries  

SciTech Connect

The so-called Casimir effect is one of the most interesting macro-quantum effects. Being negligible on the macro-scale it becomes a governing factor below structure sizes of 1 {mu}m where it accounts for typically 100 kN m-2. The force does not depend on gravity, or electric charge but solely on the materials properties, and geometrical shape. This makes the effect a strong candidate for micro(nano)-mechanical devices M(N)EMS. Despite a long history of research the theory lacks a uniform description valid for arbitrary geometries which retards technical application. We present an advanced state-of-the-art numerical tool overcoming all the usual geometrical restrictions, capable of calculating arbitrary 3D geometries by utilizing the Casimir Polder approximation for the Casimir force.

Sedmik, Rene; Tajmar, Martin [ARC Seibersdorf research Gmbh, Business field Space Propulsion, A-2444 Seibersdorf (Austria)

2007-01-30

66

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

NASA Astrophysics Data System (ADS)

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.

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

2011-03-01

67

Structural control on fault geometry: Example of the Grevena MS 6.6, normal faulting earthquake  

NASA Astrophysics Data System (ADS)

In this paper we present a three-dimensional velocity structure of the Kozani-Grevena region, a relatively low-seismicity area of the western margin of the Internal Hellenides, which was struck by a MS=6.6 earthquake on May 13, 1995. P wave arrival times from 656 aftershocks are inverted to resolve the velocity structure of the upper 12 km of the crust. The 1995, ruptured fault (Dheskati fault) lies at the southeastern end of a 35-km-long, normal fault (the Servia fault). The crustal heterogeneities identified by tomography help to constrain the geometry and structure of the 1995 fault and the rupture evolution during the mainshock. The aftershocks and the velocity structure define a fault dipping ˜35° toward NW, which from 5 km depth splays upward into two nearly parallel shallow faults. The slip during the mainshock and the aftershocks all were concentrated along the deeper portion of the fault, while the limited slip observed at the surface occurred on the northern of the two shallower splays (the Paleochori fault). It appears that the lithological heterogeneities of the shallow crust are responsible for the splaying of the main fault upward. Our work stresses the importance of crustal structure in determining fault geometry and segmentation and rupture evolution.

Chiarabba, C.; Selvaggi, G.

1997-10-01

68

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

NASA Astrophysics Data System (ADS)

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

Wei, Wei; Fu, Li-Yun

2014-09-01

69

Relationship of Fault Geometry to Catastrophic Outflow on Mars  

NASA Astrophysics Data System (ADS)

We present results from studies of large outflow channels on Mars that suggest fault morphology is a critical factor for the trapping and catastrophic release of water on Mars, resulting in large flooding events. On Earth, hot springs are commonly concentrated around fault relays, bends, and fault tips, where jointing forms in zones of concentrated stress promoting tensile failure. Examples of fault controlled hydrothermal activity have been documented in the Coso Geothermal Field in California, Southern Seismic Zone in Iceland, Waiotapu Geothermal Field in New Zealand, Killoran Fault in Ireland, and throughout the southwestern United States. On Earth, abrupt changes in the water table, as well as the formation of sand-boils and springs, are associated with earthquakes, and their spatial distribution is related to the geometry of the earthquake slip patch. A similar process may occur on Mars, where hydrothermal waters collect in highly fractured zones at fault relays, and are released catastrophically during an earthquake event. Two examples of large outflow channels on Mars, Mangala and Athabasca Valles, appear to be sourced in a relay zone. Other Martian examples show sourcing at fault bends and fault tips. Data from the instruments on Mars Reconnaissance Orbiter will help us to further understand this mechanism by which large flood events may occur. High resolution images from HiRISE will be used to map these fault systems and estimate outflow rates, and data from CRISM will be used to identify regions of past high temperature fluid flow on the surface of Mars.

Davatzes, A.; Gulick, V.

2006-12-01

70

A 3-D Quasi-static Model for a Variety of Slip Behaviors on a Subduction Fault  

Microsoft Academic Search

— Earthquake faultings have a wide variety of slip behaviors, such as, a log-linear frequency-magnitude relation, characteristic earthquakes, slow slip events, and so on. We report a model which can reproduce a certain variety of observed complex slip behaviors on a fault. Our 3-D model simulates the seismic cycle on a shallow dipping subduction fault in a homogeneous elastic half-space,

Hitoshi Hirose; Kazuro Hirahara

2004-01-01

71

Determining Fault Geometry from the Distribution of Coseismic Fault Slip Related to the 2006 Taitung Earthquake, Eastern Taiwan  

E-print Network

Determining Fault Geometry from the Distribution of Coseismic Fault Slip Related to the 2006, we identified the event's fault geo- metry and reconstructed the distribution of coseismic fault slip coseismic rupture on the main north­south fault, yet close enough in time to be associated with coseismic

Lee, Jian-Cheng

72

3-D geometry calibration and markerless electromagnetic tracking with a mobile C-arm  

NASA Astrophysics Data System (ADS)

The design of mobile X-ray C-arm equipment with image tomography and surgical guidance capabilities involves the retrieval of repeatable gantry positioning in three-dimensional space. Geometry misrepresentations can cause degradation of the reconstruction results with the appearance of blurred edges, image artifacts, and even false structures. It may also amplify surgical instrument tracking errors leading to improper implant placement. In our prior publications we have proposed a C-arm 3D positioner calibration method comprising separate intrinsic and extrinsic geometry calibration steps. Following this approach, in the present paper, we extend the intrinsic geometry calibration of C-gantry beyond angular positions in the orbital plane into angular positions on a unit sphere of isocentric rotation. Our method makes deployment of markerless interventional tool guidance with use of high-resolution fluoro images and electromagnetic tracking feasible at any angular position of the tube-detector assembly. Variations of the intrinsic parameters associated with C-arm motion are measured off-line as functions of orbital and lateral angles. The proposed calibration procedure provides better accuracy, and prevents unnecessary workflow steps for surgical navigation applications. With a slight modification, the Misalignment phantom, a tool for intrinsic geometry calibration, is also utilized to obtain an accurate 'image-to-sensor' mapping. We show simulation results, image quality and navigation accuracy estimates, and feasibility data acquired with the prototype system. The experimental results show the potential of high-resolution CT imaging (voxel size below 0.5 mm) and confident navigation in an interventional surgery setting with a mobile C-arm.

Cheryauka, Arvi; Barrett, Johnny; Wang, Zhonghua; Litvin, Andrew; Hamadeh, Ali; Beaudet, Daniel

2007-03-01

73

Which Fault Orientations Occur during Oblique Rifting? Combining Analog and Numerical 3d Models with Observations from the Gulf of Aden  

NASA Astrophysics Data System (ADS)

Oblique rift systems like the Gulf of Aden are intrinsically three-dimensional. In order to understand the evolution of these systems, one has to decode the fundamental mechanical similarities of oblique rifts. One way to accomplish this, is to strip away the complexity that is generated by inherited fault structures. In doing so, we assume a laterally homogeneous segment of Earth's lithosphere and ask how many different fault populations are generated during oblique extension inbetween initial deformation and final break-up. We combine results of an analog and a numerical model that feature a 3D segment of a layered lithosphere. In both cases, rift evolution is recorded quantitatively in terms of crustal fault geometries. For the numerical model, we adopt a novel post-processing method that allows to infer small-scale crustal fault orientation from the surface stress tensor. Both models involve an angle of 40 degrees between the rift normal and the extensional direction which allows comparison to the Gulf of Aden rift system. The resulting spatio-temporal fault pattern of our models shows three normal fault orientations: rift-parallel, extension-orthogonal, and intermediate, i.e. with a direction inbetween the two previous orientations. The rift evolution involves three distinct phases: (i) During the initial rift phase, wide-spread faulting with intermediate orientation occurs. (ii) Advanced lithospheric necking enables rift-parallel normal faulting at the rift flanks, while strike-slip faulting in the central part of the rift system indicates strain partitioning. (iii) During continental break-up, displacement-orthogonal as well as intermediate faults occur. We compare our results to the structural evolution of the Eastern Gulf of Aden. External parts of the rift exhibit intermediate and displacement-orthogonal faults while rift-parallel faults are present at the rift borders. The ocean-continent transition mainly features intermediate and displacement-orthogonal faults. The fault pattern agrees very well with the analog and numerical model results, except for the displacement-orthogonal fault orientation of the initial rift stage. This orientation, however, coincides with the trend of inherited Mesozoic basins indicating the overprinting influence of structural inheritance.

Autin, J.; Brune, S.

2013-12-01

74

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

NASA Astrophysics Data System (ADS)

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.

Aquè, R.; Tavarnelli, E.

2012-04-01

75

A study of the Herald-Phillipstown fault in the Wabash Valley using drillhole and 3-D seismic reflection data  

NASA Astrophysics Data System (ADS)

In June 2009, a 2.2 square mile 3-D high resolution seismic reflection survey was shot in southeastern Illinois in the Phillipstown Consolidated oilfield. A well was drilled in the 3-D survey area to tie the seismic to the geological data with a synthetic seismogram from the sonic log. The objectives of the 3-D seismic survey were three-fold: (1) To image and interpret faulting of the Herald-Phillipstown Fault using drillhole-based geological and seismic cross-sections and structural contour maps created from the drillhole data and seismic reflection data, (2) To test the effectiveness of imaging the faults by selected seismic attributes, and (3) To compare spectral decomposition amplitude maps with an isochron map and an isopach map of a selected geologic interval (VTG interval). Drillhole and seismic reflection data show that various formation offsets increase near the main Herald-Phillipstown fault, and that the fault and its large offset subsidiary faults penetrate the Precambrian crystalline basement. A broad, northeast-trending 10,000 feet wide graben is consistently observed in the drillhole data. Both shallow and deep formations in the geological cross-sections reveal small horst and graben features within the broad graben created possibly in response to fault reactivations. The HPF faults have been interpreted as originally Precambrian age high-angle, normal faults reactivated with various amounts and types of offset. Evidence for strike-slip movement is also clear on several faults. Changes in the seismic attribute values in the selected interval and along various time slices throughout the whole dataset correlate with the Herald-Phillipstown faults. Overall, seismic attributes could provide a means of mapping large offset faults in areas with limited or absent drillhole data. Results of the spectral decomposition suggest that if the interval velocity is known for a particular formation or interval, high-resolution 3-D seismic reflection surveys could utilize these amplitudes as an alternative seismic interpretation method for estimating formation thicknesses. A VTG isopach map was compared with an isochron map and a spectral decomposition amplitude map. The results reveal that the isochron map strongly correlates with the isopach map as well as the spectral decomposition map. It was also found that thicker areas in the isopach correlated with higher amplitude values in the spectral decomposition amplitude map. Offsets along the faults appear sharper in these amplitudes and isochron maps than in the isopach map, possibly as a result of increased spatial sampling.

Kroenke, Samantha E.

76

3D modeling to characterize lamina cribrosa surface and pore geometries using in vivo images from normal and glaucomatous eyes  

PubMed Central

En face adaptive optics scanning laser ophthalmoscope (AOSLO) images of the anterior lamina cribrosa surface (ALCS) represent a 2D projected view of a 3D laminar surface. Using spectral domain optical coherence tomography images acquired in living monkey eyes, a thin plate spline was used to model the ALCS in 3D. The 2D AOSLO images were registered and projected onto the 3D surface that was then tessellated into a triangular mesh to characterize differences in pore geometry between 2D and 3D images. Following 3D transformation of the anterior laminar surface in 11 normal eyes, mean pore area increased by 5.1 ± 2.0% with a minimal change in pore elongation (mean change = 0.0 ± 0.2%). These small changes were due to the relatively flat laminar surfaces inherent in normal eyes (mean radius of curvature = 3.0 ± 0.5 mm). The mean increase in pore area was larger following 3D transformation in 4 glaucomatous eyes (16.2 ± 6.0%) due to their more steeply curved laminar surfaces (mean radius of curvature = 1.3 ± 0.1 mm), while the change in pore elongation was comparable to that in normal eyes (?0.2 ± 2.0%). This 3D transformation and tessellation method can be used to better characterize and track 3D changes in laminar pore and surface geometries in glaucoma. PMID:23847739

Sredar, Nripun; Ivers, Kevin M.; Queener, Hope M.; Zouridakis, George; Porter, Jason

2013-01-01

77

3D modeling to characterize lamina cribrosa surface and pore geometries using in vivo images from normal and glaucomatous eyes.  

PubMed

En face adaptive optics scanning laser ophthalmoscope (AOSLO) images of the anterior lamina cribrosa surface (ALCS) represent a 2D projected view of a 3D laminar surface. Using spectral domain optical coherence tomography images acquired in living monkey eyes, a thin plate spline was used to model the ALCS in 3D. The 2D AOSLO images were registered and projected onto the 3D surface that was then tessellated into a triangular mesh to characterize differences in pore geometry between 2D and 3D images. Following 3D transformation of the anterior laminar surface in 11 normal eyes, mean pore area increased by 5.1 ± 2.0% with a minimal change in pore elongation (mean change = 0.0 ± 0.2%). These small changes were due to the relatively flat laminar surfaces inherent in normal eyes (mean radius of curvature = 3.0 ± 0.5 mm). The mean increase in pore area was larger following 3D transformation in 4 glaucomatous eyes (16.2 ± 6.0%) due to their more steeply curved laminar surfaces (mean radius of curvature = 1.3 ± 0.1 mm), while the change in pore elongation was comparable to that in normal eyes (-0.2 ± 2.0%). This 3D transformation and tessellation method can be used to better characterize and track 3D changes in laminar pore and surface geometries in glaucoma. PMID:23847739

Sredar, Nripun; Ivers, Kevin M; Queener, Hope M; Zouridakis, George; Porter, Jason

2013-07-01

78

Two-dimensional scatter integration method for brachytherapy dose calculations in 3D geometry  

NASA Astrophysics Data System (ADS)

In brachytherapy clinical practice, applicator shielding and tissue heterogeneities are usually not explicitly taken into account. None of the existing dose computational methods are able to reconcile accurate dose calculation in complex three-dimensional (3D) geometries with high efficiency and simplicity. We propose a new model that performs two-dimensional integration of the scattered dose component. The model calculates the effective primary dose at the point of interest and estimates the scatter dose as a superposition of the scatter contributions from pyramid-shaped minibeams. The approach generalizes a previous scatter subtraction model designed to calculate the dose for axial points in simple cylindrically symmetric geometry by dividing the scattering volume into spatial regions coaxial with the source-to-measurement point direction. To allow for azimuthal variation of the primary dose, these minibeams were divided into equally spaced azimuthally distributed pyramidal volumes. The model uses precalculated scatter-to-primary ratios (SPRs) for collimated isotropic sources. Effective primary dose, which includes the radiation scattered in the source capsule, is used to achieve independence from the source structure. For realistic models of the HDR and PDR sources, the algorithm agrees with Monte Carlo within 2.5% and for the type 6702 seed within 6%. The 2D scatter integration (2DSI) model has the potential to estimate the dose behind high-density heterogeneities both accurately and efficiently. The algorithm is much faster than Monte Carlo methods and predicts the dose around sources with different -ray energies and differently shaped capsules with high accuracy.

Kirov, Assen S.; Williamson, Jeffrey F.

1997-11-01

79

[Breast volume assessment based on 3D surface geometry: verification of the method using MR imaging].  

PubMed

Differences in breast volume and contour are subjectively estimated by surgeons. 3D surface imaging using 3D scanners provides objective breast volume quantification, but precision and accuracy of the method requires verification. Breast volumes of five test individuals were assessed using a 3D surface scanner. Magnetic resonance imaging (MRI) reference volumes were obtained to verify and compare the 3D scan measurements. The anatomical thorax wall curvature was segmented using MRI data and compared to the interpolated curvature of the posterior breast volume delimitation of 3D scan data. MRI showed higher measurement precision, mean deviation (expressed as percentage of volume) of 1.10+/-0.34% compared to 1.63+/-0.53% for the 3D scanner. Mean MRI [right (left) breasts: 638 (629)+/-143 (138) cc] and 3D scan [right (left) breasts: 493 (497)+/-112 (116) cc] breast volumes significantly correlated [right (left) breasts: r=0.982 (0.977), p=0.003 (0.004)]. The posterior thorax wall of the 3D scan model showed high agreement with the MRI thorax wall curvature [mean positive (negative) deviation: 0.33 (-0.17)+/-0.37 cm]. High correspondence and correlation of 3D scan data with MRI-based verifications support 3D surface imaging as sufficiently precise and accurate for breast volume measurements. PMID:18601619

Eder, Maximilian; Schneider, Armin; Feussner, Hubertus; Zimmermann, Alexander; Höhnke, Christoph; Papadopulos, Nikolaos A; Kovacs, Laszlo

2008-06-01

80

Statistical mechanics of the 3D axi-symmetric Euler equations in a Taylor-Couette geometry  

E-print Network

Statistical mechanics of the 3D axi-symmetric Euler equations in a Taylor-Couette geometry Simon ? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 simon.thalabard@cea.fr 1 hal-00829488,version3-16Nov2013 #12;3 Statistical mechanics-symmetric microcanonical ensemble . . . 10 3.2 Statistical mechanics of the toroidal field

Paris-Sud XI, Université de

81

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

Microsoft Academic Search

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

A. A. Barka; K. Kadinsky-Cade

1988-01-01

82

Relating fault geometry and aseismic slip along the Haiyuan fault creeping segment  

NASA Astrophysics Data System (ADS)

Recent observations point out the relationship between the fault geometry and earthquake rupture processes. Bends, jogs and other geometric features along faults are known to influence the initiation, the propagation and the arrest of large earthquakes. Space-based geodetic techniques, such as GPS or InSAR, allow to locate seismic asperities along faults by mapping and inverting inter-, co- and post-seismic surface displacement fields. Such methods outline in particular a clear relationship between the coseismic slip distribution and the fault surface geometry. Here, we intend to relate the inter-seismic fault behavior with the fault geometry. We focus on the Haiyuan fault, China, one of the major left-lateral fault system that accommodates relative block motion in Tibet. We study the junction area in between the 240 km-long, 1920 Mw8 Haiyuan earthquake rupture trace, to the east, and the eastern end of the millennial Tianzhu seismic gap that ruptured in the past onto Mw8 type earthquakes, to the west. This junction is marked by a 35 km-long creeping segment recently revealed by InsAR, limited to the east by a km-scale pull-apart basin. The average creep rate over the 2003-2009 period is 5±1 mm/yr and is equivalent to the present day tectonic loading rate, suggesting no strain accumulation during this period. We analyze in details how the creep distribution is related to geometric features along this creeping section. Here, we use Envisat data, spanning the 2003-2009 period, to map the along strike distribution and the temporal evolution of the surface creep. We analyze data from 1 descending and 2 ascending tracks using the ROI PAC processing chain combined with the NSBAS chain, developed to enhance coherence in areas of rough topography. We focus SAR images using a common doppler value and combine them into interferograms using an adaptive topographic spectral range filtering technique. We assume a linear dependence of the LOS phase with the topography to remove the atmospheric phase screen from the stratified troposphere. We then apply a smoothed time series analysis method to derive maps of the ground deformation. Finally, we measure in details, using fault perpendicular profiles, the along strike shallow creep distribution and its evolution over the 6 years observation period. Following roughness analysis studies along strike-slip faults, we compare the surface fault trace roughness with the surface creep distribution roughness, revealing a similar self-affine distribution of both slip and geometric asperities. Both are made of large scale, low amplitude, asperities, combined with small scale, high amplitude asperities. Furthermore, first order, km-scale, slip asperities are coincident with the km-scale geometric segments along the fault. We therefore relate the fault geometry with the spatial distribution of the creep. We show that their relationship does not depend on time, revealing no smoothing of the geometric asperities, at least during the period of observation. We then explore the temporal behavior of slip, assessing for the dynamics of slip bursts. Our results reveal a power-law distribution of the size of the slip bursts and highlight local interactions between slip bursts, suggesting an avalanche-like behavior of the creep along the studied segment.

Jolivet, R.; Candela, T.; Lasserre, C.; Renard, F.; Doin, M.; Klinger, Y.

2012-12-01

83

On the Differential Geometry of 3D Flow Patterns: Generalized Helicoids and Diffusion MRI Analysis  

Microsoft Academic Search

Configurations of dense locally parallel 3D curves occur in medical imaging, computer vision and graphics. Exam- ples include white matter fibre tracts, textures, fur and hair. We develop a differential geometric characterization of such structures by considering the local behaviour of the associ- ated 3D frame field, leading to the associated tangential, normal and bi-normal curvature functions. Using results from

Peter Savadjiev; Steven W. Zucker; Kaleem Siddiqi

2007-01-01

84

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

NASA Astrophysics Data System (ADS)

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.

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

2009-06-01

85

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

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

86

Influence of 3 d metal atoms on the geometry, electronic structure, and stability of a Mg13H26 cluster  

NASA Astrophysics Data System (ADS)

This paper reports on the results of the theoretical investigation of magnesium hydride nanoclusters doped with 3 d metals (from Sc to Zn). The influence of transition metal atoms on the geometry, electronic structure, and energy characteristics of the clusters has been analyzed. The results of the performed calculations have been compared with the available experimental data. This comparison has made it possible to predict which 3 d transition elements can serve as the most effective catalysts for the improvement of the thermodynamic characteristics of MgH2.

Shelyapina, M. G.; Siretskiy, M. Yu.

2010-09-01

87

3D Simulations of M 7 Earthquakes on the Wasatch Fault, Utah, Part I: Long-Period (01 Hz) Ground Motion  

E-print Network

%­9%. Worldwide, there are few near-fault strong ground- motion records from M 6 normal-faulting earthquakes 3D Simulations of M 7 Earthquakes on the Wasatch Fault, Utah, Part I: Long-Period (0­1 Hz) Ground predict ground motions in the Salt Lake basin (SLB) during M 7 earthquakes on the Salt Lake City segment

Olsen, Kim Bak

88

3D Simulations of M 7 Earthquakes on the Wasatch Fault, Utah, Part II: Broadband (010 Hz) Ground Motions and Nonlinear Soil Behavior  

E-print Network

exceed estimates from four recent ground-motion prediction equations (GMPEs) at near-fault ( distances. The overprediction of the near-fault GMPE values is largely eliminated after corrections 3D Simulations of M 7 Earthquakes on the Wasatch Fault, Utah, Part II: Broadband (0­10 Hz) Ground

Olsen, Kim Bak

89

Reassembling 3D Thin Fragments of Unknown Geometry in Cultural Heritage  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

90

Modelling Rupture Dynamics of a Planar Fault in 3-D Half Space by Boundary Integral Equation Method: An Overview  

NASA Astrophysics Data System (ADS)

In this article, we first reviewed the method of boundary integral equation (BIEM) for modelling rupture dynamics of a planar fault embedded in a 3-D elastic half space developed recently (ZHANG and CHEN, 2005a,b). By incorporating the half-space Green's function, we successfully extended the BIEM, which is a powerful tool to study earthquake rupture dynamics on complicated fault systems but limited to full-space model to date, to half-space model. In order to effectively compute the singular integrals in the kernels of the fundamental boundary integral equation, we proposed a regularization procedure consisting of the generalized Apsel-Luco correction and the Karami-Derakhshan algorithm to remove all the singularities, and developed an adaptive integration scheme to efficiently deal with those nonsingular while slowly convergent integrals. The new BIEM provides a powerful tool for investigating the physics of earthquake dynamics. We then applied the new BIEM to investigate the influences of geometrical and physical parameters, such as the dip angle (?) and depth (h) of the fault, radius of the nucleation region (R asp), slip-weakening distance (D c ), and stress inside (T i ) and outside (T e ) the nucleation region, on the dynamic rupture processes on the fault embedded in a 3-D half space, and found that (1) overall pattern of the rupture depends on whether the fault runs up to the free surface or not, especially for strike-slip, (2) although final slip distribution is influenced by the dip angle of the fault, the dip angle plays a less important role in the major feature of the rupture progress, (3) different value of h, ?, R asp, T e , T i and D c may influence the balance of energy and thus the acceleration time of the rupture, but the final rupture speed is not controlled by these parameters.

Chen, Xiaofei; Zhang, Haiming

2006-03-01

91

The analytic nodal diffusion solver ANDES in multigroups for 3D rectangular geometry: Development and performance analysis  

Microsoft Academic Search

In this work we address the development and implementation of the analytic coarse-mesh finite-difference (ACMFD) method in a nodal neutron diffusion solver called ANDES. The first version of the solver is implemented in any number of neutron energy groups, and in 3D Cartesian geometries; thus it mainly addresses PWR and BWR core simulations.The details about the generalization to multigroups and

Juan-Andrés Lozano; Nuria García-Herranz; Carol Ahnert; José-María Aragonés

2008-01-01

92

Nonlinear waves on the surface of a dielectric liquid in a horizontal electric field in 3D geometry: Exact solutions  

NASA Astrophysics Data System (ADS)

It has been shown that waves of arbitrary configuration in 3D geometry may propagate without distortion along the surface of a dielectric liquid in the direction of a horizontal electric field. This situation occurs for the high-permittivity liquids in the case of a sufficiently high external field when the effect of electrostatic forces dominates. A general solution of the equations of motion that describes the interaction of counterpropagating waves of a small but finite amplitude has been obtained.

Zubarev, N. M.

2009-05-01

93

Partisn calculations of 3D radiation transport benchmarks for simple geometries with void regions  

Microsoft Academic Search

We have solved the 3D radiation transport benachmark problems proposed by Prof Kobayashi using the transport code PARTISN. We have used different angular discretizations represented by the Sn method of various orders of n to investigate the resultant sensitivity of the solution. In addition, we have employed our first collision source method as incorporated in the code to mitigate the

Raymond E. Alcouffe

2001-01-01

94

Deformed phase space for 3d loop gravity and hyperbolic discrete geometries  

E-print Network

We revisit the loop gravity space phase for 3D Riemannian gravity by algebraically constructing the phase space $T^*\\mathrm{SU}(2)\\sim\\mathrm{ISO}(3)$ as the Heisenberg double of the Lie group $\\mathrm{SO}(3)$ provided with the trivial cocyle. Tackling the issue of accounting for a non-vanishing cosmological constraint $\\Lambda \

Valentin Bonzom; Maité Dupuis; Florian Girelli; Etera R. Livine

2014-02-10

95

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

96

Effects of Training Method and Gender on Learning 2D\\/3D Geometry  

Microsoft Academic Search

This article reports the findings of an experimental study involving 36 primary school students (16 girls, 20 boys, Mean age = 9.5 years, age range: 8-10 years) in geometrical understanding of 2D and 3D objects. Students were assigned into two experimental groups and one control group based on a stratified random sampling procedure. The first experimental group trained in an

Samsudin Khairulanuar; Abd Rashid Nazre; Omar Khan Sairabanu; Fabil Norasikin

2010-01-01

97

Mesoscopic hydrogel molding to control the 3D geometry of bioartificial muscle tissues  

PubMed Central

This protocol describes a cell/hydrogel molding method for precise and reproducible biomimetic fabrication of three-dimensional (3D) muscle tissue architectures in vitro. Using a high aspect ratio soft lithography technique, we fabricate polydimethylsiloxane (PDMS) molds containing arrays of mesoscopic posts with defined size, elongation and spacing. On cell/hydrogel molding, these posts serve to enhance the diffusion of nutrients to cells by introducing elliptical pores in the cell-laden hydrogels and to guide local 3D cell alignment by governing the spatial pattern of mechanical tension. Instead of ultraviolet or chemical cross-linking, this method utilizes natural hydrogel polymerization and topographically constrained cell-mediated gel compaction to create the desired 3D tissue structures. We apply this method to fabricate several square centimeter large, few hundred micron-thick bioartificial muscle tissues composed of viable, dense, uniformly aligned and highly differentiated cardiac or skeletal muscle fibers. The protocol takes 4–5 d to fabricate PDMS molds followed by 2 weeks of cell culture. PMID:19798085

Bian, Weining; Liau, Brian; Badie, Nima

2010-01-01

98

Flow prediction in cerebral aneurysms based on geometry reconstruction from 3D rotational angiography.  

PubMed

We present an immersed boundary (IB) method for the simulation of steady blood flow inside a realistic cerebral aneurysm. We reconstruct a segment of the cerebrovascular system that contains an aneurysm, by using medical images obtained with three dimensional rotational angiography (3DRA). The main focus is on evaluating the sensitivity of flow predictions to the various steps of the vascular reconstruction process. Starting from the raw medical data, we analyze the fluid-mechanical consequences of the steps needed to generate the IB masking function for our simulations. We illustrate the IB method by applying it to a realistic aneurysm and investigate the role of (i) numerical resolution of the geometry; (ii) the selection of the specific vascular segment used in the simulations; and (iii) the influence of the smoothness of the periodic vessel extension to complete the computational model. Because of an unavoidable degree of uncertainty in the medical images, the geometry of the vessels and the aneurysm can be reconstructed only approximately. We also incorporate these slight uncertainties in the masking function by introducing inner and outer 'bounding' geometries and analyze the sensitivity of the flow predictions to these variations in the masking function. The numerical solutions computed in the inner and outer bounding geometries provide practical upper and lower bounds for basic flow properties, thus quantifying the reliability of the numerical solution, subject to uncertainties in the geometry of the flow domain. PMID:23785013

Mikhal, J; Kroon, D J; Slump, C H; Geurts, B J

2013-07-01

99

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

PubMed

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

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

2014-06-10

100

Geometry of rollover: Origin of complex arrays of antithetic and synthetic crestal faults  

Microsoft Academic Search

Rollovers form by the collapse or bending of a hanging wall as it slides over bends in a normal fault. Once the authors know the particle motion of the collapse, commonly antithetic Coulomb shear, they can develop a simple relationship between fault shape and rollover geometry that is a function of the relative rates of fault slip and sedimentation. The

R. E. Bischke; J. Suppe

1990-01-01

101

Identifying Faults in the Variable Geometry System of a Gas Turbine Compressor  

Microsoft Academic Search

The influence of faults in the variable geometry (variable stator vanes) system of a multistage axial compressor, on the performance of an industrial gas turbine is investigated. An experimental investigation has been conducted, by implanting such faults into an operating gas turbine. The faults examined are individual stator vane mistuning of different magnitude, and located at different stages.

A. Tsalavoutas; K. Mathioudakis; A. Stamatis; M. Smith

2001-01-01

102

Geometry and growth of an inner rift fault pattern: the Kino Sogo Fault Belt, Turkana Rift (North Kenya)  

NASA Astrophysics Data System (ADS)

A quantitative analysis is presented of the scaling properties of faults within the exceptionally well-exposed Kino Sogo Fault Belt (KSFB) from the eastern part of the 200-km-wide Turkana rift, Northern Kenya. The KSFB comprises a series of horsts and grabens within an arcuate 40-km-wide zone that dissects Miocene-Pliocene lavas overlying an earlier asymmetric fault block. The fault belt is ˜150 km long and is bounded to the north and south by transverse (N50°E and N140°E) fault zones. An unusual feature of the fault system is that it accommodates very low strains (<1%) and since it is no older than 3 Ma, it could be characterised by extension rates and strain rates that are as low as ˜0.1 mm/yr and 10 -16 s -1, respectively. Despite its immaturity, the fault system comprises segmented fault arrays with lengths of up to 40 km, with individual fault segments ranging up to ˜9 km in length. Fault length distributions subscribe to a negative exponential scaling law, as opposed to the power law scaling typical of other fault systems. The relatively long faults and segments are, however, characterised by maximum throws of no more than 100 m, providing displacement/length ratios that are significantly below those of other fault systems. The under-displaced nature of the fault system is attributed to early stage rapid fault propagation possibly arising from reactivation of earlier underlying basement fabrics/faults or magmatic-related fractures. Combined with the structural control exercised by pre-existing transverse structures, the KSFB demonstrates the strong influence of older structures on rift fault system growth and the relatively rapid development of under-displaced fault geometries at low strains.

Vétel, William; Le Gall, Bernard; Walsh, John J.

103

Templated 3D Ultrathin CVD Graphite Networks with Controllable Geometry: Synthesis and Application As Supercapacitor Electrodes.  

PubMed

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

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

2014-11-12

104

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

PubMed Central

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

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

2012-01-01

105

Geometry and kinematics of glaciotectonic deformation superimposed on the Cenozoic fault-tectonic framework in the central Polish Lowlands  

NASA Astrophysics Data System (ADS)

The distribution of glaciotectonic structures can be controlled by the occurrence of tectonic or neotectonic faulting of the pre-Quaternary basement. The faulted and thus undulated pre-Quaternary basement influenced the thinning or pinching out of weak deformable surficial sediments and could play a role of buried obstacles to forcing by ice-sheets. In both cases, such faulting could result in a predisposition to the development of glaciotectonic deformations. The present study has demonstrated how the geometry and kinematics of the glaciotectonic structures was controlled by the pre-Quaternary framework related to the Kleczew graben tectonics (the central Polish Lowlands). The assumption has been made in this study that the tectonic fractures and faults could influence the reduction of strength and mechanical anisotropy within the pre-Quaternary sediments, which were also remobilised by glaciotectonic forces. The renewed stress build-up by the glaciotectonic forces assumed herein could reactivate the pre-existing fractures and faults at a lower stress level rather than produce new structures that require a higher stress level. The results presented in this study are focused on detailed structural and kinematic analysis of the glaciotectonic faults and fractures. For each glaciotectonic fault studied, the slip vector was directly calculated based on the orientation of the fault striations and indirectly calculated from analysis of the small fractures that developed along the fault. Additionally, the data from this analysis were integrated with the surface-based 3D structural model obtained from the borehole data. This approach revealed the relationships between the geometry, orientation and kinematics of the glaciotectonic structures and the tectonic framework of the pre-Quaternary basement. The different modes of glaciotectonic faulting were determined, depending on the geometry and orientation of the pre-existing reactivated faults and fractures with respect to the direction of the glaciotectonic contraction. In addition to reverse dip-slip displacements, the strike-slip and oblique-slip displacements were recognised. This study was performed in the Kleczew graben (the middle part of the Polish Lowlands) in which the Quaternary and the Miocene sediments are affected by glaciotectonic deformations. Moreover, the Miocene sediments were also tectonically deformed in response to the development of the graben.

W?odarski, Wojciech

2014-06-01

106

Fault spacing in the El Teniente Mine, central Chile: Evidence for nonfractal fault geometry  

NASA Astrophysics Data System (ADS)

We utilize the excellent rock exposure provided by the network of mining tunnels in El Teniente Mine, Central Chile, to test the applicability of fractal fault spacing laws to a ˜2 km × 3 km × 1.3 km body of crystalline rock in an Andean shear zone. Fractal spacing laws can be particularly useful because they allow prediction of fault spacing at unsampled scales. Because of the restrictions of tunnel geometry in the mine we use only "scanline", one-dimensional, analyses. The large number of parallel tunnels allows us to assess the consistency of one-dimensional scanline samples over a two-dimensional area. We use two methods: 1) an interval counting technique and 2) standard cumulative statistics to test the hypothesis of fractal fault geometry in the shear zone. The interval counting method produces deceptively good fits to a fractal distribution. In fact, by analyzing the residuals and differential slopes of interval counting and cumulative statistical plots and by comparison with synthetic fractal, negative exponential, and log-normal distribution data, we conclude that a negative exponential distribution best describes fault spatial distribution at the mine. We present three possible explanations for the negative exponential spacing distribution: 1) the rock body is at the earliest stage in a deformational path that will produce varying spacing distributions as deformation proceeds, 2) the spacing distribution is inherited through joint reactivation, and 3) the present spacing distribution is the result of a superposition of two spacing distributions each of which is not necessarily negative exponential. Additionally, we attempt to use the deviation of mean spacings in parallel scanlines (after Wu and Pollard (1995)) to further classify deformational maturity. We show that this method cannot be used to compare population development in faults which follow a negative exponential spacing distribution because of the negative exponential's equivalence of mean and standard deviation. Instead we use a relative measure of parallel scanline deviation to compare regions. The distinctly smaller standard deviation of mean spacings in one region (the T3 Isla region) may be a signature of increased local finite strain accumulation.

Brooks, Benjamin A.; Allmendinger, Richard W.; de la Barra, Iván Garrido

1996-06-01

107

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

108

A photoelastic study of the effects of surface geometry on fault movements  

E-print Network

. The displacements along faults with either abrupt, discontinuous changes in orientation ("ramp" obstructions) or smooth, continuous changes (" sinusoidal bump" obstructions) are variable, owing to the irregular, fault-plane geometry. Stress concentrations develop... of slip along the entire fault. Abrupt changes produce larger stress concentrations at the crack tips than do smooth changes; the latter produce larger contact loads. Principal-stress orientations are a clue to possible directions of secondary faulting...

Barber, David Williams

2012-06-07

109

The 3d Spin Geometry of the Quantum Two-Sphere  

Microsoft Academic Search

We study a three-dimensional differential calculus Omega 1S^2q on the standard Podles quantum two-sphere S2q, coming from the Woronowicz 4D+ differential calculus on the quantum group SUq(2). We use a frame bundle approach to give an explicit description of Omega 1S^2q and its associated spin geometry in terms of a natural spectral triple over S2q. We equip this spectral triple

Simon Brain; Giovanni Landi

2010-01-01

110

Fast Hologram Synthesis for 3D Geometry Models using Graphics Hardware  

Microsoft Academic Search

The holographic visualization of three-dimensional object geometry still represents a major challenge in computa- tional 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

Christoph Petz; Marcus Magnor

2003-01-01

111

Detailed 3D Architecture of a Thrust Fault System and Associated Folding: Nankai Trough Accretionary Wedge  

Microsoft Academic Search

3-D seismic data recently acquired in the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) region off the Kii peninsula of Honshu Island, Japan, images a modern accretionary prism in unprecedented detail. Although this large (12 x 56 km), deep (>12 km) survey was shot to image the entire outer forearc region, the excellent pre-stack depth migrated imaging also permits detailed interpretation

C. M. Streiff; H. J. Tobin; G. F. Moore

2008-01-01

112

Predictive Modeling of the Evolution of Fault Structure: 3-D Modeling and Coupled Geomechanical/Flow Simulation  

NASA Astrophysics Data System (ADS)

Reconstruction of geological structures has the potential to provide additional insight into the effect of the depositional history on the current-day geomechanical and hydro-geologic state. Accurate modeling of the reconstruction process is, however, complex, necessitating advanced procedures for the prediction of fault formation and evolution within fully coupled geomechanical, fluid flow and temperature fields. In this paper, a 3-D computational approach is presented that is able to forward model complex structural evolution with multiple intersecting faults that exhibit large relative movement within a coupled geomechanical/flow environment. The approach adopts the Lagrangian method, complemented by robust and efficient automated adaptive meshing techniques, an elasto-plastic constitutive model based on critical state concepts, and global energy dissipation regularized by inclusion of fracture energy in the equations governing state variable evolution. The proposed model is validated by comparison of 2-D plane strain and 3-D thin-slice predictions of a bench-scale experiment, and then applied to two conceptual coupled geomechanical/fluid flow field-scale benchmarks.

Thornton, D. A.; Crook, A. J. L.

2014-09-01

113

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

NASA Astrophysics Data System (ADS)

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.

Naumov, Dmitri

2013-04-01

114

Relation Between the 3D-Geometry of the Coronal Wave and Associated CME During the 26 April 2008 Event  

NASA Technical Reports Server (NTRS)

We study the kinematical characteristics and 3D geometry of a large-scale coronal wave that occurred in association with the 26 April 2008 flare-CME event. The wave was observed with the EUVI instruments aboard both STEREO spacecraft (STEREO-A and STEREO-B) with a mean speed of approx 240 km/s. The wave is more pronounced in the eastern propagation direction, and is thus, better observable in STEREO-B images. From STEREO-B observations we derive two separate initiation centers for the wave, and their locations fit with the coronal dimming regions. Assuming a simple geometry of the wave we reconstruct its 3D nature from combined STEREO-A and STEREO-B observations. We find that the wave structure is asymmetric with an inclination toward East. The associated CME has a deprojected speed of approx 750 +/- 50 km/s, and it shows a non-radial outward motion toward the East with respect to the underlying source region location. Applying the forward fitting model developed by Thernisien, Howard, and Vourlidas we derive the CME flux rope position on the solar surface to be close to the dimming regions. We conclude that the expanding flanks of the CME most likely drive and shape the coronal wave.

Temmer, M.; Veronig, A. M.; Gopalswamy, N.; Yashiro, S.

2011-01-01

115

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

116

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

SciTech Connect

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.

Cullen, D.E.

1997-11-22

117

The Role of Faulting on the Growth of a Carbonate Platform: Evidence from 3D Seismic Analysis and Section Restoration  

NASA Astrophysics Data System (ADS)

Tectonics in addition to other environmental factors impacts the growth of carbonate platforms and plays an important role in shaping the internal architecture of the platforms. Detailed of faults and fractures development and healing in carbonate environment have not been explored sufficiently. Using 3D seismic and well data, we attempt to reconstruct the structural evolution of a Miocene carbonate platform in Central Luconia Province, offshore Malaysia. Luconia Province is located in the NW coast of Borneo and has become one of the largest carbonate factories in SE Asia. Seismic interpretations including seismic attribute analysis are applied to the carbonate platform to discern its sedimentology and structural details. Detailed seismic interpretations highlight the relationships of carbonate deposition with syn-depositional faulting. Branching conjugate faults are common in this carbonate platform and have become a template for reef growth, attesting lateral facies changes within the carbonate environments. Structural restoration was then appropriately performed on the interpreted seismic sections based on sequential restoration techniques, and provided images different from those of horizon flattening methods. This permits us to compensate faults' displacement, remove recent sediment layers and finally restore the older rock units prior to the fault motions. It allows prediction of platform evolution as a response to faulting before and after carbonate deposition and also enhances the pitfalls of interpretation. Once updated, the reconstructions allow unravelling of the un-seen geological features underneath the carbonate platform, such as paleo-structures and paleo-topography which in turn reflects the paleo-environment before deformations took place. Interestingly, sections balancing and restoration revealed the late-phase (Late Oligocene-Early Miocene) rifting of South China Sea, otherwise difficult to visualize on seismic sections. Later it is shown that this carbonate platform was possibly originated from two or more connected reef build-ups. The platform evolution in terms of tectonic influences on carbonate growth and development may serve as a case example for re-evaluation of pre-Late Miocene structures as a new potential target for hydrocarbon exploration in Central Luconia Province. Eventually, techniques used in this study might be of interest to oil and gas explorers in carbonate system.

Nur Fathiyah Jamaludin, Siti; Pubellier, Manuel; Prasad Ghosh, Deva; Menier, David; Pierson, Bernard

2014-05-01

118

In vitro analog of human bone marrow from 3D scaffolds with biomimetic inverted colloidal crystal geometry  

PubMed Central

In vitro replicas of bone marrow can potentially provide a continuous source of blood cells for transplantation and serve as a laboratory model to examine human immune system dysfunctions and drug toxicology. Here we report the development of an in vitro artificial bone marrow based on a 3D scaffold with inverted colloidal crystal (ICC) geometry mimicking the structural topology of actual bone marrow matrix. To facilitate adhesion of cells, scaffolds were coated with a layer of transparent nanocomposite. After seeding with hematopoietic stem cells (HSCs), ICC scaffolds were capable of supporting expansion of CD34+ HSCs with B-lymphocyte differentiation. Three-dimensional organization was shown to be critical for production of B cells and antigen specific-antibodies. Functionality of bone marrow constructs was confirmed by implantation of matrices containing human CD34+ cells onto the backs of severe combined immunodeficiency (SCID) mice with subsequent generation of human immune cells. PMID:19042018

Nichols, Joan E.; Cortiella, Joaquin; Lee, Jungwoo; Niles, Jean A.; Cuddihy, Meghan; Wang, Shaopeng; Cantu, Andrea; Mlcak, Ron; Valdivia, Esther; Yancy, Ryan; Bielitzki, Joseph; McClure, Matthew L.; Kotov, Nicholas A.

2009-01-01

119

Multiphysics Simulations of the Complex 3D Geometry of the High Flux Isotope Reactor Fuel Elements Using COMSOL  

SciTech Connect

A research and development project is ongoing to convert the currently operating High Flux Isotope Reactor (HFIR) of Oak Ridge National Laboratory (ORNL) from highly-enriched Uranium (HEU U3O8) fuel to low-enriched Uranium (LEU U-10Mo) fuel. Because LEU HFIR-specific testing and experiments will be limited, COMSOL is chosen to provide the needed multiphysics simulation capability to validate against the HEU design data and calculations, and predict the performance of the LEU fuel for design and safety analyses. The focus of this paper is on the unique issues associated with COMSOL modeling of the 3D geometry, meshing, and solution of the HFIR fuel plate and assembled fuel elements. Two parallel paths of 3D model development are underway. The first path follows the traditional route through examination of all flow and heat transfer details using the Low-Reynolds number k-e turbulence model provided by COMSOL v4.2. The second path simplifies the fluid channel modeling by taking advantage of the wealth of knowledge provided by decades of design and safety analyses, data from experiments and tests, and HFIR operation. By simplifying the fluid channel, a significant level of complexity and computer resource requirements are reduced, while also expanding the level and type of analysis that can be performed with COMSOL. Comparison and confirmation of validity of the first (detailed) and second (simplified) 3D modeling paths with each other, and with available data, will enable an expanded level of analysis. The detailed model will be used to analyze hot-spots and other micro fuel behavior events. The simplified model will be used to analyze events such as routine heat-up and expansion of the entire fuel element, and flow blockage. Preliminary, coarse-mesh model results of the detailed individual fuel plate are presented. Examples of the solution for an entire fuel element consisting of multiple individual fuel plates produced by the simplified model are also presented.

Freels, James D [ORNL] [ORNL; Jain, Prashant K [ORNL] [ORNL

2011-01-01

120

Subsurface fault geometry inferred from topographic relief and footwall geologic information: An example from the Ikoma fault zone, southwest Japan  

NASA Astrophysics Data System (ADS)

To improve seismic hazard assessment caused by inland earthquakes, it is necessary to clarify subsurface fault geometry and fault slip sense. Although seismic reflection profiles are commonly used to image subsurface fault geometry and associated deformation, there are numerous technical and conditional limitations that often prevent us seeing deeper extension of the fault. To perform the best estimate of the subsurface fault at seismogenic depth, we use all the geomorphic and geologic information to better constrain numerical fault models. Here we choose the Ikoma fault zone, east of the Osaka plain, southwest Japan, as a case study to infer subsurface fault geometry with a great deal of shallow geologic information. The Ikoma fault zone composes a part of NS-trending topographic relief of basins and ranges in Osaka-Kyoto region where significant EW contraction has been continuously occurring in the late Quaternary (Huzita, 1962). To model the east Osaka basin and the Ikoma Mountains, both of which corresponds to footwall and hanging wall of the Ikoma fault, we employ dislocation model in an elastic half space of Okada (1992). We first calculate surface displacement with a simple rectangular fault, and then compare with the present topographic profile across the fault. We find our best estimate of the fault width, dip, and top depth to maximize the cross correlation and/or to minimize the root mean square of the residual between the model and the topographic profile by grid search technique. Since we apply the dislocation model to the topographic profile across an active fault, we introduce information of the confirmed fault position at the Earth's surface into our model when calculated displacement pattern and topographic cross section are compared. Our result shows that a 14-km-wide shallow dipping thrust fault better explains the topographic relief across the Ikoma fault. However, such fault models cannot reproduce the basin-forming deformation on the footwall. Numerous geologic data of pre-Tertiary bedrock, Pleistocene to Holocene marine and non-marine sediments beneath the Osaka plane (e.g., Horikawa et al., 2003) provide several well-constrained chronological key units which allow us to incorporate the information into our models. In the case of bedrock deformation, our best estimate is a combination of fault width 19km, dip 50°, and top depth 2 km. To explain the thick Quaternary sedimentary units up to ~1,500 m on the footwall, fault dip must be deeper than 50°. None of the traditional geologic fold models (e.g., fault-propagation fold), most of which take detachment into account, can explain such significant basin subsidence. However, one could criticize limitations of the elastic half space model for the long-term geologic processes of tens of thousand years to a few million years. We thus intend to perform further experiments considering viscoelastic relaxation of lower crust, topographic change in upheaval side due to rapid surface erosion, newly-formed dislocation (fault) beyond elaselastic limit.

Tani, E.; Toda, S.

2013-12-01

121

3-D simultaneous inversion for velocity and reflector geometry using multiple classes of arrivals in a spherical coordinate frame  

NASA Astrophysics Data System (ADS)

The two key requirements in conducting 3-D simultaneous traveltime tomography on real data at the regional and global scale with multiple classes of arrival time information are (1) it needs an efficient and accurate arrival tracking algorithm for multiply transmitted, reflected (or refracted) and converted waves in a 3-D variable velocity model with embedded velocity discontinuities (or subsurface interfaces), and (2) a subdimensional inversion solver is required which can easily search for different types of model parameters to balance the trade-off between the different types of model parameter updated in the simultaneous inversion process. For these purposes, we first extend a popular grid/cell-based wavefront expanding ray tracing algorithm (the multistage irregular shortest-path ray tracing method), which previously worked only in Cartesian coordinate at the local scale, to spherical coordinates appropriate to the regional or global scale. We then incorporated a fashionable inversion solver (the subspace method) to formulate a simultaneous inversion algorithm, in which the multiple classes of arrivals (including direct and reflected arrivals from different velocity discontinuities) can be used to simultaneously update both the velocity fields and the reflector geometries. Numerical tests indicate that the new inversion method is both applicable and flexible in terms of computational efficiency and solution accuracy, and is not sensitive to a modest level of noise in the traveltime data. It offers several potential benefits over existing schemes for real data seismic imaging.

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

2014-01-01

122

Modeling 3D Dynamic Rupture on Arbitrarily-Shaped faults by Boundary-Conforming Finite Difference Method  

NASA Astrophysics Data System (ADS)

We use a new finite difference method (FDM) and the slip-weakening law to model the rupture dynamics of a non-planar fault embedded in a 3-D elastic media with free surface. The new FDM, based on boundary- conforming grid, sets up the mapping equations between the curvilinear coordinate and the Cartesian coordinate and transforms irregular physical space to regular computational space; it also employs a higher- order non-staggered DRP/opt MacCormack scheme which is of low dispersion and low dissipation so that the high accuracy and stability of our rupture modeling are guaranteed. Compared with the previous methods, not only we can compute the spontaneous rupture of an arbitrarily shaped fault, but also can model the influence of the surface topography on the rupture process of earthquake. In order to verify the feasibility of this method, we compared our results and other previous results, and found out they matched perfectly. Thanks to the boundary-conforming FDM, problems such as dynamic rupture with arbitrary dip, strike and rake over an arbitrary curved plane can be handled; and supershear or subshear rupture can be simulated with different parameters such as the initial stresses and the critical slip displacement Dc. Besides, our rupture modeling is economical to be implemented owing to its high efficiency and does not suffer from displacement leakage. With the help of inversion data of rupture by field observations, this method is convenient to model rupture processes and seismograms of natural earthquakes.

Zhu, D.; Zhu, H.; Luo, Y.; Chen, X.

2008-12-01

123

The effects of realistic fault geometry on ground motion on the Claremont - Casa Loma stepover of the San Jacinto Fault  

NASA Astrophysics Data System (ADS)

The Claremont and Casa Loma strands of the San Jacinto Fault in southern California are separated by a 25 km long extensional stepover, which bounds a sedimentary basin. Both individual strands are themselves geometrically complex. A smaller fault strand is located within the stepover, approximately halfway between the two main strands. The width of the larger stepover approaches 4 km, which has been shown by prior observational and modeling work to be close to the upper limit for stepover width through which rupture may jump. The region within and surrounding the Claremont-Casa Loma stepover is densely populated, which further emphasizes the importance of understanding the rupture and shaking hazard associated with this fault system. We use the 3D finite element method to model dynamic ruptures on the Claremont-Casa Loma stepover, incorporating geometrical complexities based on the USGS Quaternary Fault Database and the SCEC Community Fault Model, in order to investigate the ability of the rupture to propagate through the geometrical complexities in this region, as well as the resulting ground motions. As compared to a stepover model with planar segments, the overall intensity and distribution of strong motion for the complex model is reduced, but there remains a region of decreased peak motions between the end of the nucleating fault and the second fault strand. In addition, rupture directivity is diminished near each bend in the fault. Due to this break in directivity, peak ground motions near the fault are weakest immediately after the rupture turns a bend, and are strongest and more widespread immediately before the next bend. Unlike the case of a stepover with planar segments, the shape and intensity of the ground motion distribution is not symmetrical across the fault; an alternating pattern of fault bends produces an alternating pattern for which side of the fault trace experiences higher ground motion. Future work will involve incorporating a complex 3D velocity structure based on the SCEC Community Velocity Model, which should significantly improve the accuracy of our ground motion estimates.

Lozos, J.; Oglesby, D. D.; Brune, J. N.; Olsen, K. B.

2012-12-01

124

Fault and joint geometry at Raft River geothermal area, Idaho  

SciTech Connect

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 5/sup 0/ 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 50/sup 0/ and 70/sup 0/. These faults occur as conjugate pairs that are bisected by vertical extension fractures. The second set of faults dips 10/sup 0/ to 20/sup 0/ 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. The north-trending joint set is prominent in the fold's hinge. Surface joint intensity decreases in proximity to known faults, indicating that surface joint intensity mapping may be useful for locating the surface traces of faults in the reservoir.

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

1981-07-01

125

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)

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.

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

2013-12-01

126

Neural-network calibration of a multiple-line laser-camera range sensor for 3D surface-geometry measurement  

NASA Astrophysics Data System (ADS)

Single-line laser-camera range sensors require scanning over the object surface to measure three-dimensional (3D) surface geometry. Full-field 3D surface measurement techniques typically require more than one pattern to be projected and captured by camera. This paper presents a method to calibrate a multiple-line laser-camera range sensor using an artificial neural network (NN) to enable capture of full-field 3D surface geometry using a single projected pattern. The range sensor projects nineteen laser lines onto a surface. During calibration, points in 2D images are extracted from the intersections of nineteen laser profiles and horizontal lines marked on a calibration plate, for several calibration plate positions. A mapping of 2D image coordinates to 3D object coordinates is performed separately for each laser-line projection using a multi-layer perceptron (MLP) neural network. Experiments using different NN configurations found a network with two hidden layers of 43 nodes per layer using the sigmoidal activation function to generate the lowest 3D reconstruction errors. Errors were consistent errors over all calibration positions. Calibration with an acceptable error for many applications can be achieved without knowledge of the camera pose. The fast 3D reconstruction by the trained system may permit low resolution full-field 3D surface-geometry measurement in real-time.

Liu, Chris Yu-Liang; Kofman, Jonathan

2008-11-01

127

Geometry of rollover: Origin of complex arrays of antithetic and synthetic crestal faults  

SciTech Connect

Rollovers form by the collapse or bending of a hanging wall as it slides over bends in a normal fault. Once the authors know the particle motion of the collapse, commonly antithetic Coulomb shear, they can develop a simple relationship between fault shape and rollover geometry that is a function of the relative rates of fault slip and sedimentation. The dip of the rollover is a function of the angle fault bend, which is verified in some structures. A fanning of dips in the rollover is predicted for continuously flattening faults. In contrast, numerous rollovers from the US Gulf Coast, Brunei, and elsewhere do not show significant fanning of dips but show a nearly constant dip that is less than the magnitude predicted from Coulomb shear. These structures show complex arrays of small synthetic and antithetic normal faults on the crest of the rollover, including keystone grabens. High-quality seismic images show that many of these crestal faults suddenly disappear downdip, apparently to run along bedding. These observations indicate that part of the rollover collapse is by bedding slip after a critical rollover angle is reached; the bedding slip extends from the master normal fault up to the crest of the rollover where it breaks upward to be the imaged synthetic and antithetic crestal faults. Modeling of this process shows that variation in the relative rates of fault slip and sedimentation predict the different observed styles of complex crestal faulting in offshore Texas, Brunei, and elsewhere.

Bischke, R.E.; Suppe, J. (Princeton Univ., Princeton, NJ (USA))

1990-05-01

128

Holocene deposition and megathrust splay fault geometries within Prince William Sound, Alaska  

NASA Astrophysics Data System (ADS)

New high resolution sparker seismic reflection data, in conjunction with reprocessed legacy seismic data, provide the basis for a new fault, fold, and Holocene sediment thickness database for Prince William Sound, Alaska. Additionally, legacy airgun seismic data in Prince William Sound and the Gulf of Alaska tie features on these new sparker data to deeper portions of megathrust splay faults. We correlate regionally extensive bathymetric lineaments within Prince William Sound to megathrust splay faults, such as the ones that ruptured in the 1964 M9.2 earthquake. Lastly, we estimate Holocene sediment thickness within Prince William Sound to better constrain the Holocene fault history throughout the region. We identify three seismic facies related to Holocene, Quaternary, and Tertiary strata that are crosscut by numerous high angle normal faults in the hanging wall of the megathrust splay faults. The crustal-scale seismic reflection profiles show splay faults emerging from 20 km depth between the Yakutat block and North American crust and surfacing as the Hanning Bay and Patton Bay faults. A change in exhumation rates, slip rates, and fault orientation appears near Hinchinbrook that we attribute to differences in subducted slab geometry. Based on our slip rate analysis, we calculate average Holocene displacements of 20 m and 100 m in eastern and western Prince William Sound, respectively. Landward of two splay faults exposed on Montague Island, we observe subsidence, faulting, and landslides that record deformation associated with the 1964 and older megathrust earthquakes.

Finn, S.; Liberty, L. M.; Haeussler, P. J.; Pratt, T. L.

2011-12-01

129

3D current path in stacked devices: Metrics and challenges  

Microsoft Academic Search

Although magnetic current imaging (MCI) is useful in fault isolation of devices with 2D current distributions, MCI alone cannot give the exact information of current paths in complex 3D stacked devices. Previous work has demonstrated the ability of a simulation approach to find a short circuit in 3D geometry. This approach has been challenged in the case of dense and

H. B. Kor; F. Infante; P. Perdu; C. L. Gan; D. Lewis

2011-01-01

130

Seismic fault geometry and kinematics of the 13 May 1995 Western Macedonia (Greece) earthquake  

NASA Astrophysics Data System (ADS)

During the devastating earthquake of 13 May 1995, in the Kozani-Grevena area (Western Macedonia, Greece), many surface ruptures formed in the epicentral area. Most of these fractures were due to faulting, but some were secondary ground ruptures and landslides. Geological field work in the area has shown that the Aliakmon river neotectonic fault consists of several (three or more) fault strands: the Servia, the Rymnio and the Paleochori-Sarakina strands. Using geological criteria, all of these fault strands were judged to be active faults affecting recent (Holocene) deposits and scree. The main new surface fractures caused by the earthquake, and particularly those clearly of tectonic origin, follow systematically the traces of the last two neotectonic fault strands, forming a new fracture line. This tectonic line, trending ENE-WSW (N 70 °), coincides with the focal mechanism solution and the satelite image major lineament. Both the geological and instrumental seismological data suggest that the seismogenic fault is a segment of the Aliakmon river neotectonic fault zone situated among the villages of Rymnio, Paleochori, Sarakina, Kentro and Nisi. The total length of the reactivated fault segment is about 30km long overall and is separated from the non-activated Servia fault segment by a geometrical seismic segment barrier near the village of Goules. The seismic fault is a normal fault trending ENE-WSW and dipping to NNW, with high angle at the surface and low angle at depth. The majority of the epicentres of the seismic sequence were distributed on the hangingwall of this reactivated fault segment. Additionaly a series of subparallel antithetic surface fractures, mainly striking E-W or ENE-WSW and dipping to the South, following previous neotectonic strike-slip faults, were reactivated during the earthquake with the geometry of normal faults antithetic to the main seismic fault. The most important of these are the Chromio-Varis-Myrsina fracture line (length 15km), along the Vourinos corridor dextral strike-slip structure and the Felli fracture line (length 6 km) along the Felli sinistral strike-slip fault. An interpretation of the geometry and kinematics of the reactivated faults is shown in the proposed geological model with simplified cross sections.

Mountrakis, D.; Pavlides, S.; Zouros, N.; Astaras, Th.; Chatzipetros, A.

131

Tectonic evolution and deep to shallow geometry of Nagamachi-Rifu Active Fault System, NE Japan  

NASA Astrophysics Data System (ADS)

The Nagamachi-Rifu fault is an active reverse fault which trends NE-SW across the central part of Sendai City for over 21 km distance. The fault does not emerge at the surface and, accompanied with the Dainenji-yama fault, shows wedge thrusting in the Tertiary sediments. The amount of net slip of the master part of the Nagamachi-Rifu fault is estimated to be one mm/year. Seismic reflection profiles across the fault plus a gravity anomaly reveal the thicker Neogene sediments on the hanging wall rather than on the footwall. The Neogene sedimentary basin was formed by normal faulting in early Miocene under an extensional stress regime associated with the formation of the northern Honshu rift system. Due to shortening deformation since the Pliocene, this Miocene normal fault reactivated as a reverse fault. Judging from the CMP deep seismic reflection profile and location of the 1998 M5.0 Sendai earthquake, the deep geometry of the Nagamachi-Rifu fault is listric.

Sato, Hiroshi; Imaizumi, Toshifumi; Yoshida, Takeyoshi; Ito, Hisao; Hasegawa, Akira

2002-11-01

132

Influence of cratonic lithosphere on slab geometry and mantle flow: insights from 3D time-dependent modelling.  

NASA Astrophysics Data System (ADS)

Recent studies show a clear correlation between the occurrence of flat subduction and the proximity of areas of high elastic/thermal thickness in the overriding plate. A plausible explanation is that cold overriding plates lead to colder mantle wedge, increasing the hydrodynamic suction and decreasing the slab dip. In particular, recent numerical modeling has shown that the presence of cratonic lithosphere in the overriding plate has a significant effect on subducting slabs. In this study we quantify the influence of cratonic areas in the overriding plate on subduction dynamics. We present 3D thermo-mechanical and time-dependent numerical models of buoyancy-driven subduction processes. A non-Newtonian pseudo-plastic rheology is assumed. Different simulations have been performed to quantify the effect of different factors, such as the craton width, thermal thickness and distante to the trench. Modelling results indicate that presence of cratonic lithosphere in the overriding plate produces strong along-trench variations of the slab geometry. These variations are maintained and propagated at great depths as the slab sinks deeper into the mantle. Significant trench-parallel flow in the mantle wedge is generated by time-dependent changes in slab dip. For cases of reduced slab pull, the slab and the base of the craton become coupled, which causes a dramatic reduction of subduction velocity and the formation of a slab gap. The presence of cratons may have an important role on subduction episodicity and provide a new mechanism to explain slab gaps in areas where cratons have been located close to trenches, as is the case of South America and the Cenozoic subduction of North America. We further emphasize that the lithospheric structure of the overriding plate should be taken into account in analysis and modelling studies of subduction zones.

Taramón, Jorge M.; Rodríguez-González, Juan; Negredo, Ana M.

2014-05-01

133

Source scaling relations and along-strike segmentation of slow slip events in a 3-D subduction fault model  

NASA Astrophysics Data System (ADS)

Scaling between slip event duration and equivalent moment is diagnostic of the underlying physics of rupture process. For episodic slow slip events (SSEs) in subduction zones, their moment-duration relation is not clearly defined and shows considerable variation among individual margins where multiple episodes of SSEs are geodetically detected. Here I set up a 3-D planar thrust fault model within the framework of rate-state friction to study the spatiotemporal evolution of slip and stress during SSEs. SSE source properties, including along-strike length, duration, equivalent moment, and stress drop, are quantified, and their scaling relations are compared to observations. Modeled SSEs have nearly constant stress drops of 0.001 to 0.01 MPa, due to near-lithostatic pore pressure at the SSE depths. The modeled moment-duration scaling is between 1 (linear) and 2 (squared). When multiple SSEs appear simultaneously along the strike, the stress interaction between approaching slip fronts results in higher average propagation speeds for longer lengths, which leads to a scaling close to 2. When SSEs are well offset in space and time, stress interaction is negligible and the scaling is close to 1. Two types of SSE along-strike segmentation gaps are identified from model results. The "primary" gaps are persistent segmentation boundaries due to along-strike variation of effective normal stress, while the "secondary" gaps evolve through SSE cycles and reflect the stress condition within a primary segment. This implies that some geodetically inferred SSE segmentation boundaries may result from slower slip velocities below the resolution limits of geodetic inversion models.

Liu, Yajing

2014-08-01

134

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

USGS Publications Warehouse

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

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

1991-01-01

135

Contradicting Estimates of Location, Geometry, and Rupture History of Highly Active Faults in Central Japan  

NASA Astrophysics Data System (ADS)

Accurate location and geometry of seismic sources are critical to estimate strong ground motion. Complete and precise rupture history is also critical to estimate the probability of the future events. In order to better forecast future earthquakes and to reduce seismic hazards, we should consider over all options and choose the most likely parameter. Multiple options for logic trees are acceptable only after thorough examination of contradicting estimates and should not be a result from easy compromise or epoche. In the process of preparation and revisions of Japanese probabilistic and deterministic earthquake hazard maps by Headquarters for Earthquake Research Promotion since 1996, many decisions were made to select plausible parameters, but many contradicting estimates have been left without thorough examinations. There are several highly-active faults in central Japan such as Itoigawa-Shizuoka Tectonic Line active fault system (ISTL), West Nagano Basin fault system (WNBF), Inadani fault system (INFS), and Atera fault system (ATFS). The highest slip rate and the shortest recurrence interval are respectively ~1 cm/yr and 500 to 800 years, and estimated maximum magnitude is 7.5 to 8.5. Those faults are very hazardous because almost entire population and industries are located above the fault within tectonic depressions. As to the fault location, most uncertainties arises from interpretation of geomorphic features. Geomorphological interpretation without geological and structural insight often leads to wrong mapping. Though non-existent longer fault may be a safer estimate, incorrectness harm reliability of the forecast. Also this does not greatly affect strong motion estimates, but misleading to surface displacement issues. Fault geometry, on the other hand, is very important to estimate intensity distribution. For the middle portion of the ISTL, fast-moving left-lateral strike-slip up to 1 cm/yr is obvious. Recent seismicity possibly induced by 2011 Tohoku earthquake show pure strike-slip. However, thrusts are modeled from seismic profiles and gravity anomalies. Therefore, two contradicting models are presented for strong motion estimates. There should be a unique solution of the geometry, which will be discussed. As to the rupture history, there is plenty of paleoseismological evidence that supports segmentation of those faults above. However, in most fault zones, the largest and sometimes possibly less frequent earthquakes are modeled. Segmentation and modeling of coming earthquakes should be more carefully examined without leaving them in contradictions.

Okumura, K.

2011-12-01

136

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

NASA Astrophysics Data System (ADS)

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.

Munn, Jonathan; Parker, Beth

2013-04-01

137

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

E-print Network

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 ...

Peyton, Shelly R.

138

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

USGS Publications Warehouse

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.

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

139

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

140

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

E-print Network

Los Angeles Location of Photo Long Valley Caldera WalkerLaneBelt AA B !"##$%&'"()*& !"+%*,&-"%*& N 3d as seen in Long Valley, California (Bursik & Sieh, 1989) (figure 1). Figure 1: (A) Shows Hawthorne located in central western Nevada as well as the location of Long Valley, California. (B) The 3d seismic

141

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

E-print Network

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

Guerin, Gilles

142

Fault geometry and slip distribution associated with the 1939 Erzincan Earthquake (M: 7.9), North Anatolian Fault  

NASA Astrophysics Data System (ADS)

The North Anatolian Fault (NAF) ruptured in a westward-migrating sequence of large earthquakes between 1939 and 1999. The 1939 (M:7.9) earthquake which is the first and the largest event in the sequence produced 330 km-long multi-segment surface ruptures. We have performed a serial study on the fault geometry and revision of slip data associated with this event based on detailed field mapping and slip measurements. The 1939 earthquake (M 7.9) nucleated on the eastern portion of the rupture. Main body of the rupture extended along the master strand of the NAF between Erzincan and Niksar basins. However, a part of 76 km-long the westernmost portion of the rupture directed towards on the Ezinepazar? splay fault. Additionally, triggered surface rupture was formed on the eastern segment of the Erbaa-Niksar fault that mainly ruptured in the 1942 earthquake. The 1939 rupture is divided into five fault segments based on slip distribution and fault jogs. We named the segments as follows; Erzincan, Refahiye, Su?ehri, Re?adiye and Ezinepazar? segments from east to west. Length of segments varies from 42 to 90 km. Collected slip data from 95 measurement localities reveal that the amount of average slip varies between 2.30 to 8.8 m. and the slip distribution is not uniform along the entire rupture zone. Slip maxima of 10.5 m was measured on Refahiye segment. Based on the field data, we conclude that: 1) total length of the surface rupture associated with the 1939 earthquake is 330 km. 2) the amount of slip along the entire 1939 rupture is larger than that in previous study 3) the larger revisited slip distribution suggests that the magnitude of the 1939 event could be revisited based on the empirical law of surface slip and magnitude. 4) Each segment displays different amount of average slip along rupture zone. This may be one of the indicators for individual paleoseismic history on each fault segment. Large slips on the Refahiye and Su?ehri segments imply a longer return period than the other segments in the last two events. This result is consistent with the paleoseismological findings (Hartlep et al, 2006). Refahiye segment might have been ruptured in 1254 historical event before 1939 event. The Re?adiye segment probably ruptured in the 1668 Great Anatolian earthquake. Key Words: segment structure, slip distribution, 1939 surface rupture, North Anatolian Fault.

Emre, Omer; Kondo, Hisao; Ozalp, Selim; Elmaci, Hasan; Kurcer, Akin

2010-05-01

143

Application of a new 3D Finite-element Elasto-visco-plastic Modeling Technique to Simulate Origination and Evolution of the San Andreas Fault System  

NASA Astrophysics Data System (ADS)

The San Andreas Fault System (SAFS) in central and northern California is a complex of faults that accommodate the relative motion between the Pacific plate and the North American plate. This system began to develop about 20 Myr ago in response to the northward migration of the Mendocino triple junction. As the triple junction migrated northward along the plate boundary, the slab being subducted beneath North America was replaced by hot asthenospheric material in a slab window or slab gap and the transform deformation along the plate boundary developed simultaneously with thermal re-equilibration of the lithosphere. Large spatial (several 100 km) and temporal (20 Myr) scale, as well as essentially 3D style and strongly non-linear character of the associated brittle-ductile deformation processes require new efficient modeling technique. Our approach is based on the implicit time integration of momentum, mass and energy conservation equations and employs temperature- and stress-dependant elastoviscoplastic rheology. The code called SLIM3D ( Semi-Lagrangian Implicit Modeler) combines Lagrangian formulations and particle-based remeshing procedure. The locking-free hexahedral finite element with hourglass control is adopted to maintain robustness and efficiency of computation. The notion of consistent linearization of stress update algorithm and derivation of tangent modulus tensor is used to achieve optimal convergence rate of global Newton-Raphson equilibrium iteration at a large time step. First results of a full 3D modeling demonstrate that the general features of the SAFS can indeed result from strike-slip deformation of the continental margin subjected to the strong heating and then cooling according to the "slab-window" scenario. The key factor controlling spacing of the major faults is the amount of friction weakening achieved at the major faults, in accord with the results of our previous extended 2D models. The model-predicted faults distribution as well as deformation and thermal patterns are consistent with the SAFS, if friction coefficient at faults can be decreased at high shear strain by at least 3-5 times relative to its usual value of 0.5-0.7. We also discuss effects on SAFS deformation patterns of 3D lithospheric heterogeneity of North America margin and boundary tractions imposed by the Gorda plate.

Popov, A.; Sobolev, S.; Zoback, M.

2006-12-01

144

Control of preexisting faults and near-surface diapirs on geometry and kinematics of fold-and-thrust belts (Internal Prebetic, Eastern Betic Cordillera)  

NASA Astrophysics Data System (ADS)

We have determined, for the first time, the 3D geometry of a sector of the eastern Internal Prebetic comprised between Parcent and Altea diapirs, combining structural, borehole and multichannel seismic reflection data. The tectonic structure of the Jurassic-Cretaceous carbonate series is characterized by regional ENE-WSW fold-and-thrusts that interact with oblique N-S and WNW-ESE folds, detached over Triassic evaporites and clays. The structural style comprises box-shape anticlines, and N-vergent anticlines with vertical to overturned limbs frequently bordered by reverse and strike-slip faults. The anticlines surround a triangular broad synclinal structure, the Tárbena basin, filled by a late Oligocene to Tortonian sedimentary sequence that recorded folding and thrusting history. The location and geometrical characteristics of fold-and-thrusts may be controlled by the positive inversion of pre-existing Mesozoic normal faults, and by the position and shape of near-surface diapirs composed of Triassic rocks. Therefore, we propose an initial near-surface diapir emplacement of Triassic evaporitic rocks driven by late Jurassic to early Cretaceous rifting of the southern Iberian paleomargin. Thrusting and folding started during the latest Oligocene (?28-23 Ma) roughly orthogonal to the NW-directed shortening. Deformation migrated to the south during Aquitanian (?23-20 Ma), when tectonic inversion implied the left-lateral transpressive reactivation of N-S striking former normal faults and right-lateral/reverse reactivation of inherited WNW-ESE faults. We show two mechanisms driving the extrusion of the diapirs during contraction: lateral migration of a pre-existing near-surface diapir associated with dextral transpression; and squeezing of a previous near-surface diapir at the front of an anticline. Our study underlines the value of 3D geological modeling to characterize geometry and kinematics of complex fold-and-thrust belts influenced by preexisting faults and near-surface diapirs.

Pedrera, Antonio; Marín-Lechado, Carlos; Galindo-Zaldívar, Jesús; García-Lobón, José Luis

2014-07-01

145

Applications of energy release rate techniques to part-through cracks in plates and cylinders. Volume 1. ORMGEN-3D: a finite element mesh generator for 3-dimensional crack geometries  

Microsoft Academic Search

This report (Volume 1) describes the ORMGEN-3D (Oak Ridge Mesh GENerator - 3D) finite element mesh generator program for computational fracture mechanics analysis. The program automatically generates a three-dimensional (3-D) finite element model for six different crack geometries. These geometries include flat plates with straight or curved surface cracks and cylinders with part-through cracks on the outer or inner surface.

B. R. Bass; J. W. Bryson

1982-01-01

146

A 3-D velocity model for earthquake location from combined geological and geophysical data: a case study from the TABOO near fault observatory (Northern Apennines, Italy)  

NASA Astrophysics Data System (ADS)

Accurate hypocenter location at the crustal scale strongly depends on our knowledge of the 3D velocity structure. The integration of geological and geophysical data, when available, should contribute to a reliable seismic velocity model in order to guarantee high quality earthquake locations as well as their consistency with the geological structure. Here we present a 3D, P- and S-wave velocity model of the Upper Tiber valley region (Northern Apennines) retrieved by combining an extremely robust dataset of surface and sub-surface geological data (seismic reflection profiles and boreholes), in situ and laboratory velocity measurements, and earthquake data. The study area is a portion of the Apennine belt undergoing active extension where a set of high-angle normal faults is detached on the Altotiberina low-angle normal fault (ATF). From 2010, this area hosts a scientific infrastructure (the Alto Tiberina Near Fault Observatory, TABOO; http://taboo.rm.ingv.it/), consisting of a dense array of multi-sensor stations, devoted to studying the earthquakes preparatory phase and the deformation processes along the ATF fault system. The proposed 3D velocity model is a layered model in which irregular shaped surfaces limit the boundaries between main lithological units. The model has been constructed by interpolating depth converted seismic horizons interpreted along 40 seismic reflection profiles (down to 4s two way travel times) that have been calibrated with 6 deep boreholes (down to 5 km depth) and constrained by detailed geological maps and structural surveys data. The layers of the model are characterized by similar rock types and seismic velocity properties. The P- and S-waves velocities for each layer have been derived from velocity measurements coming from both boreholes (sonic logs) and laboratory, where measurements have been performed on analogue natural samples increasing confining pressure in order to simulate crustal conditions. In order to test the 3D velocity model, we located a selected dataset of the 2010-2013 TABOO catalogue, which is composed of about 30,000 micro-earthquakes (see Valoroso et al., same session). Earthquake location was performed by applying the global-search earthquake location method NonLinLoc, which is able to manage strong velocity contrasts as that observed in the study area. The model volume is 65km x 55km x 20km and is parameterized by constant velocity, cubic cells of side 100 m. For comparison, we applied the same inversion code by using the best 1D model of the area obtained with earthquake data. The results show a significant quality improvement with the 3D model both in terms of location parameters and correlation between seismicity distribution and known geological structures.

Latorre, Diana; Lupattelli, Andrea; Mirabella, Francesco; Trippetta, Fabio; Valoroso, Luisa; Lomax, Anthony; Di Stefano, Raffaele; Collettini, Cristiano; Chiaraluce, Lauro

2014-05-01

147

3-D Terrain Corrections to Heat Flow Data, Topographically-Driven Groundwater Flow, and the Strength of the San Andreas Fault at Parkfield, CA  

NASA Astrophysics Data System (ADS)

The lack of a detectable heat flow anomaly along the San Andreas Fault (SAF) constitutes one important piece of evidence used to argue that the fault supports low shear stresses (<20 MPa averaged over the upper 10 km). However, key uncertainties in existing heat flow data, such as the effects of heat advection by topographically-driven groundwater flow, topographic refraction (terrain effects), subsurface heterogeneity (refraction caused by variable thermal conductivity), and uncertainty in thermal conductivity limit the utility of such analyses. Previous studies using heat flow data to investigate the strength of the SAF have taken into account effects of topographically-driven groundwater flow along a transect NW of the SAFOD site and included limited two-dimensional heat flow terrain effects, but remain inconclusive for interpreting possible frictional heating along the SAF near Parkfield, CA due to significant scatter remaining in the data and uncertainty in the extent of three-dimensional terrain effects. Here, we re-evaluate the effects of topographically-driven groundwater flow at Parkfield using full 3-D corrections to the heat flow data and including additional transects. In this study, we apply three-dimensional terrain corrections to temperature data for 22 boreholes near the SAFOD site. The corrected thermal gradients and available thermal conductivity data allow us to determine heat flow values free of terrain effects. The difference in heat flow for each borehole between published 2-D corrected values and the values corrected for 3-D terrain effects range from 0.2 to 21.0 mW/m2, 6.9% on average. The standard deviation of the heat flow data is reduced by 25.8% by including the 3-D correction. Error bars based on the standard deviation of the thermal conductivity measurements for each borehole range from +/-3.2 to +/-25.7 mW/m2 (10.3% on average for all data and 6.8% for high-quality data alone). We use the finite-element modeling code, SUTRA, to simulate steady-state coupled heat and groundwater flow within three cross-sections perpendicular to the fault. We consider a suite of hydrologic (groundwater flow) conditions to evaluate effects of topographically-driven groundwater flow and compute simulated heat flow values for both strong and weak fault frictional heat sources. Simulated heat flow values are corrected for all terrain effects using a two-dimensional Birch method correction, and then compared with the 3-D corrected heat flow data to evaluate plausible hydrologic and fault strength scenarios. For high-permeability scenarios, we predict a large variability in heat flow, as well as a systematic decrease in heat flow with elevation. These patterns are not present in the data, allowing us to estimate an upper limit on advection caused by groundwater flow. In general, models that incorporate a weak fault fit the data better than those with a strong fault. Uncertainty from poorly constrained (undersampled) thermal conductivity in some boreholes, and scatter caused by subsurface thermal refraction due to heterogeneous thermal conductivity structure still remain, but a pronounced near fault heat flow anomaly as predicted for a strong fault is not evident.

Fulton, P. M.; Saffer, D. M.; Bekins, B. A.; Harris, R. N.

2003-12-01

148

Compact transient thermal model for 3D ICs with liquid cooling via enhanced heat transfer cavity geometries  

Microsoft Academic Search

The advent of 3D stacked ICs with accumulating heat fluxes stresses thermal reliability and is responsible for temperature driven performance deterioration of the electronic systems Hot spots with power densities typically rising up to 250 W\\/cm2 are not acceptable, with the result of limited performance improvement in next generation high-performance microprocessor stacks. Unfortunately traditional back-side cooling only scales with the

Arvind Sridhar; Alessandro Vincenzi; Martino Ruggiero; Thomas Brunschwiler; David Atienza

2010-01-01

149

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

Microsoft Academic Search

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

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

2009-01-01

150

3D Mechanical Modeling of Earthquake Cycle on a Frictional Strike-Slip Fault Embedded in a Viscoelastic Lithosphere  

Microsoft Academic Search

Large earthquakes do not occur regularly. They often happen as sequences or clusters, which are separated by long period of quiescence. For example, the north Anatolian fault, which produced more than ten large eartquakes bewteen 1939 and 1999, has been relatively quiet during the centuries before. Understanding the causes of this behaviour is essential to produce a realistic model of

J. Chery; A. Provost; R. Hassani

2002-01-01

151

2D and 3D Numerical Models of Inductive SFCL  

Microsoft Academic Search

The Superconducting Fault Current Limiter (SFCL) can be used to limit the short-circuit current level in electrical networks. The inductive SFCL works like a transformer with shorted secondary HTS winding. Because of the iron core, the inductive SFCL is not axially symmetrical and should be modeled in 3D geometry. On the other hand, the 2D modeling gives much more computational

S. Kozak; T. Janowski; G. Wojtasiewicz

2007-01-01

152

A head-neck-eye system that learns fault-tolerant saccades to 3-D targets using a self-organizing neural model.  

PubMed

This paper describes a head-neck-eye camera system that is capable of learning to saccade to 3-D targets in a self-organized fashion. The self-organized learning process is based on action perception cycles where the camera system performs micro saccades about a given head-neck-eye camera position and learns to map these micro saccades to changes in position of a 3-D target currently in view of the stereo camera. This motor babbling phase provides self-generated movement commands that activate correlated visual, spatial and motor information that are used to learn an internal coordinate transformation between vision and motor systems. The learned transform is used by resulting head-neck-eye camera system to accurately saccade to 3-D targets using many different combinations of head, neck, and eye positions. The interesting aspect of the learned transform is that it is robust to a wide variety of disturbances including reduced degrees of freedom of movement for the head, neck, one eye, or any combination of two of the three, movement of head and neck as a function of eye movements, changes in the stereo camera separation distance and changes in focal lengths of the cameras. These disturbances were not encountered during motor babbling phase. This feature points to general nature of the learned transform in its ability to control autonomous systems with redundant degrees of freedom in a very robust and fault-tolerant fashion. PMID:18775642

Srinivasa, Narayan; Grossberg, Stephen

2008-11-01

153

The effects of mass redistribution due to erosion and sedimentation on the distribution of fault activity within extensional fault arrays: An investigation by using fully coupled 3D finite-element models with a landscape evolution tool.  

NASA Astrophysics Data System (ADS)

Mass redistribution on the Earth's surface creates loads that may influence the rate of crustal deformation. Using three-dimensional finite-element models solved with the commercial finite-element software ABAQUS and implementing the landscape evolution with the CASQUS tool (Kurfeß and Heidbach 2009) we investigate how surface processes may affect the spatiotemporal distribution of fault slip within horst and graben structures in extensional tectonic settings. The finite-element models comprised of normal faults arranged in en echelon arrays that form graben or horst structures within a 200 km x 200-km-wide and 15-km-thick upper crust. Previous studies have shown that surface processes may affect fault slip rates on normal faults during extension phases and prolong fault activity after the onset of tectonic quiescence (Maniatis et al., 2009, Turpeinen et al., in press). In the present study we show that not only the parameters controlling the surface processes (e.g. diffusion constant) have an effect on the slip rate of individual faults but also the spatial distribution of erosion and deposition affects fault slip rates to different degrees depending on the fault's position within an array. By adding a subsequent phase of tectonic quiescence to the models, we investigate how ongoing erosion and sedimentation might prolong fault slip accumulation for up to millions of years after the cessation of extension across the fault arrays. Our models show that the amount and duration of additional fault slip are controlled by parameters such as the diffusion constant, fault length and fault dip. The results of the present study therefore imply that the feedbacks of erosion and deposition on tectonics should be additionally considered when evaluating the spatial distribution of fault activity within graben and horst systems. Furthermore, the potential of erosion and sedimentation to prolong fault activity in extensional settings should be taken into account when constraining the timing of the cessation of regional extension phases. References Kurfeß, D., Heidbach, O., 2009. CASQUS: a new simulation tool for coupled 3d finite element modeling of tectonic and surface processes based on ABAQUS™ and CASCADE. Comput. Geosci. 35, 1959-1967. http://dx.doi.org/10.1016/j.cageo.2008.10.019. Maniatis, G., Kurfeß, D., Hampel, A., Heidbach, O., 2009. Slip acceleration on normal faults due to erosion and sedimentation—results from a new three-dimensional numerical model coupling tectonics and landscape evolution. Earth Planet. Sci. Lett. 284, 570-582. http://dx.doi.org/10.1016/j.epsl.2009.05.024. Turpeinen, H., Maniatis, G., Hampel, A., Slip on normal faults induced by surface processes after the cessation of regional extension—Insights from three-dimensional numerical modelling, Geomorphology (in press), http://dx.doi.org/10.1016/j.geomorph.2013.12.008

Maniatis, Georgios; Turpeinen, Heidi; Hampel, Andrea

2014-05-01

154

A split-step numerical method for the time-dependent Dirac equation in 3-D axisymmetric geometry  

NASA Astrophysics Data System (ADS)

A numerical method is developed to solve the time-dependent Dirac equation in cylindrical coordinates for 3-D axisymmetric systems. The time evolution is treated by a splitting scheme in coordinate space using alternate direction iteration, while the wave function is discretized spatially on a uniform grid. The longitudinal coordinate evolution is performed exactly by the method of characteristics while the radial coordinates evolution uses Poisson's integral solution, which allows to implement the radial symmetry of the wave function. The latter is evaluated on a time staggered mesh by using Hermite polynomial interpolation and by performing the integration analytically. The cylindrical coordinate singularity problem at r=0 is circumvented by this method as the integral is well-defined at the origin. The resulting scheme is reminiscent of non-standard finite differences. In the last step of the splitting, the remaining equation has a solution in terms of a time-ordered exponential, which is approximated to a higher order than the time evolution scheme. We study the time evolution of Gaussian wave packets, and we evaluate the eigenstates of hydrogen-like systems by using a spectral method. We compare the numerical results to analytical solutions to validate the method. In addition, we present three-dimensional simulations of relativistic laser-matter interactions, using the Dirac equation.

Fillion-Gourdeau, François; Lorin, Emmanuel; Bandrauk, André D.

2014-09-01

155

3D Investigation of an Apparent Offset Channel: A Case Study From the San Andreas Fault in the Carrizo Plain  

NASA Astrophysics Data System (ADS)

Airborne and terrestrial LiDAR topographic data can provide unprecedented spatial representations of faulting-related surface features and an opportunity to analyze and model their evolution. Analysis of high resolution topographic data from the southern San Andreas fault (B4-dataset) indicates that the average slip along the Carrizo section during the 1857 earthquake was ~5.5 m (Zielke et al., 2010). Here we present the results from >20 field-reviewed, shallow excavations surrounding a ~20 cm deep channel which has a sharp, 5 m long bend at the Bidart site along the SAF in the Carrizo Plain. Our observations show: 1) the sharp bend in the channel coincides with the trace of the 1857 fault rupture. 2) A mud flow deposit is the oldest unit to bury the surface deformed in 1857. The shallow channel is either younger than or likely contemporaneous with deposition of a pea gravel unit which sporadically overlays the post-1857 mud flow unit. 3) Pea gravel and mudflow deposits show no evidence of intense deformation compared to the underlying units which were interpreted to have deformed significantly (moletracks, fissures, apparent offsets, unit thickness changes, etc.) during 1857. 4) The sharp bend in the channel trace topography, clearly observed in field and LIDAR images, is younger than the 1857 offset and is now interpreted as a deflection. The pea gravel deposit may have been deflected around a ~5 m offset structure, but the relevant sedimentary relationships are ambiguous. 5) Subtle deformational features within the pea gravel are similar to the evidence previously documented at the Phelan Fan and LY4 paleoseismic sites (3 km and 35 km NW of Bidart), which may collectively suggest a post-1857 aftershock or moderate (pre 20th century) Cholame/Carrizo earthquake. New technologies and numerical methods provide novel opportunities for measuring and understanding processes that shape the surface of the earth. However, validation and 4-dimensional (depth and time) stratigraphic investigations are still warranted.

Grant Ludwig, L.; Akciz, S. O.; Zielke, O.; Arrowsmith, R.

2011-12-01

156

A method to characterize the 3D geometry of complex landslides in clayey soils: the Valoria, Super-Sauze and La Valette case studies  

NASA Astrophysics Data System (ADS)

Bedrock geometry drastically influences the kinematic deformation pattern of slow-moving landslides exhibiting some flow characteristics. The development of extension and compression zones within the landslide body is largely controlled by the geometry (crests, bumps, hollows) and roughness of the topography covered by the moving mass. A challenge to progress in the forecast of such type of landslides is to precisely define 3D geometrical and geomechanical models. The objective of this work is to present a methodology for 3D geometrical modelling of the landslide structure, and to discuss the main possible errors in integrating multi-source and multi-resolution data in the modelling. The methodology is presented through the analysis of three landslides with similar geomorphological features (e.g. flow-like geomorphology) and development patterns (retrogression of the crown, roto-translational failures of the upper part, and translational movements in the lower part), and for which an extensive dataset of geophysical, geotechnical and geomorphological information is available. The three cases studies are the complex Valoria earth-slide-flow located in the Northern Apennines, the Super-Sauze and La Valette mudslides in the French South Alps. All three landslides are predominantly developed in a clay-shale soil formation. First, interpretation of the multi-data information, their resolution and accuracy is presented for the landslides. Second, a procedure to construct 3D geometrical models of the landslides is proposed (by using the Rockware's Rockworks geological modeller) and the influence of the interpolation algorithms is discussed. It is demonstrated that the model uncertainty is strongly depending on the density and distribution of the input data which vary for the three landslides. The quality of several geometrical models is then compared; a best-fit is achieved by using available geological and geomorphological site interpretation.

Daehne, A.; Travelletti, J.; Malet, J.-P.; Corsini, A.; Ronchetti, F.

2009-04-01

157

The influence of pre-existing thrust faults on normal fault geometry in nature and in experiments  

Microsoft Academic Search

Relations between normal faults and pre-existing thrust faults are classically described in terms of three basic situations: normal faults can cross-cut thrust faults; they can branch out from thrust faults at depth on a de´collement level, or they can entirely reactivate thrust planes. The mechanical aspects of these types of interaction were studied by analogue modelling in which sand simulates

Vittorio Bosi; Thierry Nalpas; Jean-Pierre Brun; Philippe Davy

1995-01-01

158

Cyberchase 3D Builder  

NSDL National Science Digital Library

This Cyberchase iOS geometry app ($) enables students to use 2D nets to create 3D shapes. The app includes eight levels which increase in difficulty; increasing the complexity of the nets and combining different 3D shapes together.

Kids, Pbs

2014-01-21

159

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

160

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)

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.

Ritz, E.; Pollard, D. D.

2011-12-01

161

Geodetic slip rates in the southern San Andreas Fault system: Effects of elastic heterogeneity and fault geometry  

E-print Network

Geodetic slip rates in the southern San Andreas Fault system: Effects of elastic heterogeneity aperture radar and GPS measurements of crustal motion across the southern San Andreas Fault system Andreas and San Jacinto faults. Two possibilities have been proposed to explain this observation: large

Fialko, Yuri

162

The relationship of near-surface active faulting to megathrust splay fault geometry in Prince William Sound, Alaska  

NASA Astrophysics Data System (ADS)

We interpret regionally extensive, active faults beneath Prince William Sound (PWS), Alaska, to be structurally linked to deeper megathrust splay faults, such as the one that ruptured in the 1964 M9.2 earthquake. Western PWS in particular is unique; the locations of active faulting offer insights into the transition at the southern terminus of the previously subducted Yakutat slab to Pacific plate subduction. Newly acquired high-resolution, marine seismic data show three seismic facies related to Holocene and older Quaternary to Tertiary strata. These sediments are cut by numerous high angle normal faults in the hanging wall of megathrust splay. Crustal-scale seismic reflection profiles show splay faults emerging from 20 km depth between the Yakutat block and North American crust and surfacing as the Hanning Bay and Patton Bay faults. A distinct boundary coinciding beneath the Hinchinbrook Entrance causes a systematic fault trend change from N30E in southwestern PWS to N70E in northeastern PWS. The fault trend change underneath Hinchinbrook Entrance may occur gradually or abruptly and there is evidence for similar deformation near the Montague Strait Entrance. Landward of surface expressions of the splay fault, we observe subsidence, faulting, and landslides that record deformation associated with the 1964 and older megathrust earthquakes. Surface exposures of Tertiary rocks throughout PWS along with new apatite-helium dates suggest long-term and regional uplift with localized, fault-controlled subsidence.

Finn, S.; Liberty, L. M.; Haeussler, P. J.; Northrup, C.; Pratt, T. L.

2010-12-01

163

On the climate-geometry imbalance of Vadret da Morteratsch (Switzerland) and its response time: insights from numerical 3-D flow simulations  

NASA Astrophysics Data System (ADS)

When a glacier is subject to a change in mass balance it needs a certain amount of time to adjust its length and volume. In the literature the response time is referred to as the time a glacier takes to complete most of its adjustment to a change in mass balance, but such a broad definition is not always satisfactory. A better insight in the response time of glaciers and the main controlling factors is however crucial to improve future projections, as the evolution of glaciers in the coming decades is largely determined by their past evolution and present-day imbalance. Here we investigate the climate-geometry imbalance and the response time of Vadret da Morteratsch (Engadine, Switzerland) by using a 3-D higher-order ice flow model. In earlier studies the glacier flow model was calibrated with observed surface velocities, and used to simulate the glacier evolution since 1865 driven by a 2-D energy surface mass balance model. This modelling relies on an extensive observational dataset collected on the glacier over the last 13 years. The present-day imbalance between glacier geometry and climate is analysed by performing steady state simulations. We investigate the retreat under present-day climate and the forcing needed to maintain the present-day glacier length and volume. Subsequently we do this for the previous decades to understand how the climate-geometry imbalance changed over time. In our analysis of response times, we impose idealized step changes in mass balance and quantify the time needed to reach a new equilibrium. We analyse the factors that influence the length and volume response time, such as glacier size, glacier thickness (flow parameters), the magnitude and spatial distribution of the mass balance forcing and the differences occurring between glacier advance and retreat. Subsequently, we compare our results with simpler analytical approaches from the literature and discuss the applicability of each method to characterize the response time of Vadret da Morteratsch.

Zekollari, Harry; Huybrechts, Philippe

2014-05-01

164

Use of 3D geometry modeling of osteochondrosis-like iatrogenic lesions as a template for press-and-fit scaffold seeded with mesenchymal stem cells.  

PubMed

Computed tomography (CT) is an effective diagnostic modality for three-dimensional imaging of bone structures, including the geometry of their defects. The aim of the study was to create and optimize 3D geometrical and real plastic models of the distal femoral component of the knee with joint surface defects. Input data included CT images of stifle joints in twenty miniature pigs with iatrogenic osteochondrosis-like lesions in medial femoral condyle of the left knee. The animals were examined eight and sixteen weeks after surgery. Philips MX 8000 MX and View workstation were used for scanning parallel plane cross section slices and Cartesian discrete volume creation. On the average, 100 slices were performed in each stifle joint. Slice matrices size was 512 x 512 with slice thickness of 1 mm. Pixel (voxel) size in the slice plane was 0.5 mm (with average accuracy of +/-0.5 mm and typical volume size 512 x 512 x 100 voxels). Three-dimensional processing of CT data and 3D geometrical modelling, using interactive computer graphic system MediTools formerly developed here, consisted of tissue segmentation (raster based method combination and 5 % of manual correction), vectorization by the marching-cubes method, smoothing and decimation. Stifle- joint CT images of three individuals of different body size (small, medium and large) were selected to make the real plastic models of their distal femurs from plaster composite using rapid prototyping technology of Zcorporation. Accuracy of the modeling was +/- 0.5 mm. The real plastic models of distal femurs can be used as a template for developing custom made press and fit scaffold implants seeded with mesenchymal stem cells that might be subsequently implanted into iatrogenic joint surface defects for articular cartilage-repair enhancement. PMID:17552888

Krupa, P; Krsek, P; Javorník, M; Dostál, O; Srnec, R; Usvald, D; Proks, P; Kecová, H; Amler, E; Jancár, J; Gál, P; Plánka, L; Necas, A

2007-01-01

165

Mechanical validation of the three-dimensional intersection geometry between the Puente Hills blind-thrust system and the Whittier fault,  

E-print Network

Mechanical validation of the three-dimensional intersection geometry between the Puente Hills blind-thrust geometries of the Puente Hills blind thrust system and the Whittier fault is modeled under geodetically that seismic hazard of these faults may be underestimated by considering reverse-slip rates alone. Contraction

Cooke, Michele

166

The 2011, Mw 6.2, Christchurch earthquakes (New Zealand): faults geometry and source kinematics  

NASA Astrophysics Data System (ADS)

The geometrical characteristics and the space-time distribution of the kinematic source parameters of the 21 February 2011, Mw 6.2, Christchurch earthquake, New Zealand, have been inferred through a joint inversion of geodetic and strong-motion data. The geodetic data consist of both Global Position System (GPS), from campaign and continuous stations, and Synthetic Aperture Radar (SAR) interferograms from two ascending satellite tracks. The strong-motion data have been recorded at 10 stations located in the Canterbury Plane, offering a quite good azimuthal coverage of the event. Before performing the data inversion, several preliminary analyses on individual data-sets have been carried out, in order to find the optimal lay-out for the inversion. In particular, the consistency between GPS and InSAR data was checked and some GPS measurements, characterized by large errors, were excluded from the data-set. The strong-motion analyses were instead primarily addressed, to identify the reliable frequency range to be used, through the analysis of stability of S-wave polarization. The kinematic rupture model was obtained using the nonlinear joint inversion scheme proposed by Delouis et al. (2000), which is based on the simulated annealing algorithm. In particular, for any sub-source in which the fault plane is discretized, we explore for the direction, duration and amplitude of the slip vector, and for the rupture offset time. The geometry and orientation of the fault plane to be used in the inversion procedure is preliminarily inferred from the analysis of the geodetic data. In order to account for the complex pattern of the superficial deformation data (especially of the InSAR data), we adopted a source model consisting of two partially overlapping fault segments, whose dimensions are 15x11 and 7x7 km2, and striking at 60o and 10o, respectively. From the data inversion we found a slip distribution for the largest plane characterized by a high slip area, with a maximum amplitude of 4.2 m, localized at NE of the hypocenter. The second fault plane activated with a delay of about 4s, and a maximum slip of 2 m. Moreover, the total Source Time Function considering the two events has a total duration of about 7 s. The global seismic moment resulting from the joint inversion is about 3.0x1025 dyne cm (Mw 6.2), with an average rupture velocity of 2.0 km/s, and most of the energy release occurring on the main fault plane. The source parameters resolution is studied using both the single and joint data-sets, and applying the errors analysis for the retrieved kinematic rupture model.

Toraldo Serra, E.; Delouis, B.; Emolo, A.; Zollo, A.

2012-12-01

167

Imaging Fault Geometries With High-Resolution Seismicity Data in a Complex Normal Faulting Setting in the Central Apennines, Italy  

Microsoft Academic Search

The Umbria-Marche region (central Apennines) was struck over a period of 30 days by a series of moderate magnitude (5faulting earthquakes in 1997, accompanied by a prolonged sequence of aftershocks. We apply the double-difference earthquake location method to travel time picks and waveform cross-correlation measurements to obtain high-resolution images of these geometrically complex fault structures. This area is

L. Chiaraluce; W. L. Ellsworth; C. Chiarabba; M. Cocco

2001-01-01

168

Focal mechanisms of earthquake multiplets in the western part of the Corinth Rift (Greece): influence of the velocity model and constraints on the geometry of the active faults  

NASA Astrophysics Data System (ADS)

The composite fault plane solutions for 24 large multiplets recorded in the western part of the Corinth Rift between 2000 and 2007 are computed by jointly inverting P polarities and Sv/P, Sh/P, Sv/Sh amplitude ratios of the direct waves. The fault plane solutions are determined using 1-D and 3-D velocity models. Solutions computed with the 3-D velocity model are preferred to the ones computed with the 1-D model because overall, 3-D solutions have a better score function. They correspond essentially to E-NE/W-SW and W-NW/E-SE striking normal faults, which is consistent with the N-S extensional/vertical shortening tectonic regime of the area. For 15 multiplets, one of the nodal planes is similar to the plane delineated by the earthquakes. It is then possible to determine which nodal plane is the fault plane. The analysis of the fault plane solutions highlights a clear decrease of their dip with depth and towards the north. Several multiplets with steeply dipping fault planes (50°-60°) located at depths of 7-8 km are clearly located at the base of onshore and offshore faults that crop out close to the south border of the Corinth Gulf, indicating that these faults are steep down to 7-8 km depth. To the north, multiplets underline a low angle north-dipping structure (20°-30°) on which steep north-dipping faults could take root.

Godano, Maxime; Deschamps, Anne; Lambotte, Sophie; Lyon-Caen, Hélène; Bernard, Pascal; Pacchiani, Francesco

2014-06-01

169

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

170

3D Modeling By Consolidation Of Independent Geometries Extracted From Point Clouds - The Case Of The Modeling Of The Turckheim's Chapel (Alsace, France)  

NASA Astrophysics Data System (ADS)

Turckheim is a small town located in Alsace, north-east of France. In the heart of the Alsatian vineyard, this city has many historical monuments including its old church. To understand the effectiveness of the project described in this paper, it is important to have a look at the history of this church. Indeed there are many historical events that explain its renovation and even its partial reconstruction. The first mention of a christian sanctuary in Turckheim dates back to 898. It will be replaced in the 12th century by a roman church (chapel), which subsists today as the bell tower. Touched by a lightning in 1661, the tower then was enhanced. In 1736, it was repaired following damage sustained in a tornado. In 1791, the town installs an organ to the church. Last milestone, the church is destroyed by fire in 1978. The organ, like the heart of the church will then have to be again restored (1983) with a simplified architecture. From this heavy and rich past, it unfortunately and as it is often the case, remains only very few documents and information available apart from facts stated in some sporadic writings. And with regard to the geometry, the positioning, the physical characteristics of the initial building, there are very little indication. Some assumptions of positions and right-of-way were well issued by different historians or archaeologists. The acquisition and 3D modeling project must therefore provide the current state of the edifice to serve as the basis of new investigations and for the generation of new hypotheses on the locations and historical shapes of this church and its original chapel (Fig. 1)

Koehl, M.; Fabre, Ph.; Schlussel, B.

2014-06-01

171

Method for stochastic inverse modeling of fault geometry and connectivity using flow data  

Microsoft Academic Search

This paper focuses on fault-related uncertainties in the subsurface, which can significantly affect the numerical simulation of physical processes. Our goal is to use dynamic data and process-based simulation to update structural uncertainty in a Bayesian inverse approach. We propose a stochastic fault model where the number and features of faults are made variable. In particular, this model samples uncertainties

Nicolas Cherpeau; Guillaume Caumon; Jef K. Caers; Bruno Levy

2012-01-01

172

Lateral displacement variation and lateral tip geometry of normal faults in the Canyonlands National Park, Utah  

Microsoft Academic Search

The along-strike displacement variation of 20 well-exposed normal faults from the Canyonlands, Utah, is described and analysed. The displacement profiles of these faults are highly variable, and most irregularities can be related to fault segmentation. Many of the profiles are highly asymmetric, and this can be related to mechanical interaction in some cases. Linear displacement tapers are observed towards all

C. S. Mansfield

1998-01-01

173

Fault Separation  

NSDL National Science Digital Library

Students use gestures to explore the relationship between fault slip direction and fault separation by varying the geometry of faulted layers, slip direction, and the perspective from which these are viewed.

Ormand, Carol

174

Modelling of 3D fractured geological systems - technique and application  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

175

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

Microsoft Academic Search

In a gravel pit at the eastern margin of the Eisenstadt-Sopron Basin, a satellite of Vienna Basin (Austria), Neogene sediments\\u000a are exposed in the hanging wall of a major normal fault. The anticlinal structure and associated conjugated secondary normal\\u000a faults were previously interpreted as a rollover anticline above a listric normal fault. The spatial orientation and distribution\\u000a of sedimentary horizons

Darko Spahic; Ulrike Exner; Michael Behm; Bernhard Grasemann; Alexander Haring; Herbert Pretsch

2011-01-01

176

Subsurface geometry of the San Andreas-Calaveras fault junction: influence of the Coast Range Ophiolite  

NASA Astrophysics Data System (ADS)

Potential-field modeling, surface geologic mapping, and relocated seismicity are used to investigate the three-dimensional structure of the San Andreas-Calaveras fault junction to gain insight into regional tectonics, fault kinematics, and seismic hazard. South of the San Francisco Bay area, the San Andreas and Hayward-Calaveras fault zones join to become a single San Andreas Fault. The fault junction, as defined in this study, represents a three-dimensional volume of crust extending from San Juan Bautista in the north to Bitterwater Valley in the south, bounded by the San Andreas Fault on the southwest and the Calaveras fault zone on the northeast. South of Hollister, the Calaveras fault zone includes the Paicines, San Benito, and Pine Rock faults. Within the junction, the San Andreas and Calaveras faults are both creeping at the surface, and strike parallel to each other for about 50 km, separated by only 2 to 6 km, but never actually merge at the surface. Geophysical evidence suggests that the San Andreas and Calaveras faults dip away from each other within the northern portion of the fault junction, bounding a triangular wedge of crust. This wedge changes shape to the south as the dips of both the San Andreas and Calaveras faults vary along strike. The main trace of the San Andreas Fault is clearly visible in cross-sections of relocated seismicity as a vertical to steeply southwest-dipping structure between 5 and 10 km depth throughout the junction. The Calaveras fault dips steeply to the northeast in the northern part of the junction. Near the intersection with the Vallecitos syncline, the dip of the Calaveras fault, as identified in relocated seismicity, shallows to 60 degrees. Northeast of the Calaveras fault, we identify a laterally extensive magnetic body 1 to 8 km below the surface that we interpret as a folded 1 to 3 km-thick tabular body of Coast Range Ophiolite at the base of the Vallecitos syncline. Potential-field modeling and relocated seismicity indicate that the southwestern edge of this magnetic body is defined by a northeast-dipping structure that we interpret as part of the Calaveras fault. The base of this magnetic slab, which is folded up along the Calaveras fault, may represent a roof thrust formed by an eastward-migrating wedge of Franciscan Complex. Fragments of Coast Range Ophiolite caught up within the San Andreas-Calaveras junction may facilitate creep and slip transfer between structures that have no apparent connection at the surface. Combined geological and geophysical results suggest that during development of the junction, the Calaveras fault preferentially followed a zone of weakness represented by the roof thrust and associated Coast Range Ophiolite. The Hayward fault occupies a similar position with respect to the Coast Range Ophiolite near San Leandro to the north.

Watt, J. T.; Ponce, D. A.; Graymer, R. W.; Jachens, R. C.; Simpson, R. W.

2013-12-01

177

The origin of high frequency radiation in earthquakes and the geometry of faulting  

Microsoft Academic Search

In a seminal paper of 1967 Kei Aki discovered the scaling law of earthquake spectra and showed that, among other things, the high frequency decay was of type omega-squared. This implies that high frequency displacement amplitudes are proportional to a characteristic length of the fault, and radiated energy scales with the cube of the fault dimension, just like seismic moment.

R. Madariaga

2004-01-01

178

Simple 3D Drawing  

NSDL National Science Digital Library

Developed by Barbara Kaskosz of the University of Rhode Island and Doug Ensley of Shippensburg University, this resource from The Mathematical Association of America's Digital Classroom Resources collection will prove quite valuable for educators and anyone with an interest in computer graphics or geometry. Through this resource, visitors will learn how to draw and rotate 3D objects via a series of short tutorials. Along the way, users will learn about the mathematics behind manipulating cubes, the geometry involved with the manipulation of cubes, and they will also get a chance to work on their own structures. Overall, it's a fine resource and it offers insights for students in several different disciplines

179

Geometry Sender  

NSDL National Science Digital Library

The Geometry Sender at Keio University includes many 3D object data, including WebOOGL, off, rwx format, tutorial on data formats, and information about external viewers for 3D object on Web are available.

180

Relationship between earthquake source faults and 3D density structures derived by gravity anomaly inversion based on velocity structure in Japan  

NASA Astrophysics Data System (ADS)

In Japan, recent damaging earthquakes did not occurred along obvious active faults in Japan. It is imperative that developing a new method to extract concealed earthquake source faults. The detailed gravity anomaly distribution was published from several gravity databases in Japan. The gravity anomaly indicates the subsurface density distribution. We have investigated the validity of gravity data to extract the information of earthquake source faults. We investigated the relationship between faults and gravity anomaly. Steep gradient zones of short wavelength components of gravity anomaly surrounded several source faults. However, in gravity data process, there are several uncertainty parameters to obtain some depth information. Velocity model and density model of Japan have been constructed for strong ground simulation from various institutes and organizations, and are available to the public. In this study, the three-dimensional density structure was estimated around the earthquake source fault applying a conjugate gradient (CG) method and velocity model. The separation of gravity components was carried out constructed density models from velocity models. Long wavelength component of gravity anomaly was removed by velocity model below 30km. Initial density models around source faults were constructed from velocity model. The inverted subsurface density distributions indicated that large asperity areas corresponded to high-density areas.

Inoue, N.; Kitada, N.; Takemura, K.

2010-12-01

181

Geometry  

NSDL National Science Digital Library

Geometry is the branch of mathematics which investigates the relations, properties, and measurement of solids, surfaces, lines, and angles. It is the science of the relations of space. Sourse: Webster's Dictionary

K-12 Outreach,

182

Geometry and fault behaviour of the seismogenic coupling zone in central and southern Sumatra: constraints from teleseismic waveform inversion  

NASA Astrophysics Data System (ADS)

South and central Sumatra were affected by great subduction zone earthquakes in 1797 and 1833, with estimated moment magnitudes of 8.7-8.9 and 8.9-9.1, respectively. The area is expected to fail again in a great megathrust earthquakes in the near future. The source area of the 1833 event was located roughly between the towns Padang and Bengkulu. The 1797 event ruptured the segment to the north. In south and central Sumatra, between January of 2001 and November of 2008, 14 earthquakes with magnitudes between 6.4 and 8.4 provided waveform data of high quality that could be used to study the geometry and fault behaviour. I derived the moment tensor and hence fault mechanism, the centroid depth, and source time function using waveforms recorded at distances of 30 to 90°. In general, earthquakes did not extend into the trench but display a well defined seismic front, with a 100-130 km wide area without major seismicity occurring between the trench axis and Mentawai Islands. Waveform inversion indicates that earthquakes under the Mentawai islands occur at a depth of roughly 24 km and the megathrust fault zone dips at 12-13°. Events occurring further landwards generally show larger dips of the fault plain and occur at greater depth, indicating that the dip of the megathrust fault increases approaching Sumatra. However, fault dip and coupling behaviour changes along the coast line. Off Bengkulu (approx. 4°S to 6°S) the fault dips over approximately 180-200 km at 12-14° and dip seems to increase where the forearc Moho intersects the downgoing plate. In central Sumatra (northward of 4°S) the fault dips at approx. 12° for 120-140 km and the dip increases to 18-19° landwards of the Mentawai islands. In addition, earthquakes tend to nucleate updip of the intersection of the forearc Moho with the mantle wedge in southern Sumatra (<33 km depth), while in central Sumatra the Mw=7.9 earthquake of September 12, 2007 clearly nucleated well below the forearc Moho at 46 km depth. Consequently, while the mantle wedge in southern Sumatra might be weak (serpentinized) and did not promote seismogenic failure mantle has to be strong halfway between Padang and Bengkulu, suggesting lateral changes in coupling and properties of the forearc mantle. This fact has important implications for the risk assessment. Thus, slip along the northern portion of the 1833 rupture area and in the 1797 rupture area may extend further landward and may cause larger damage in Sumatra than slip along the southern portion of the 1833 earthquake.

Grevemeyer, I.

2009-04-01

183

Active forearc shortening in Tohoku, Japan: Constraints on fault geometry from erosion rates and fluvial longitudinal profiles  

NASA Astrophysics Data System (ADS)

Convexities in the longitudinal profiles of actively incising rivers are typically considered to represent the morphologic signal of a transient response to external perturbations in tectonic or climatic forcing. Distinguishing such knickzones from those that may be anchored to the channel network by spatial variations in rock uplift, however, can be challenging. Here, we combine stream profile analysis, 10Be watershed-averaged erosion rates, and numerical modeling of stream profile evolution to evaluate whether knickzones in the Abukuma massif of northeast Japan represent a temporal or spatial change in rock uplift rate in relation to forearc shortening. Knickzones in channels that drain the eastern flank of the Abukuma massif are characterized by breaks in slope-area scaling and separate low-gradient, alluvial upper-channel segments from high-gradient, deeply-incised lower channel segments. Average erosion rates inferred from 10Be concentrations in modern sediment below knickzones exceed erosion rates above knickzones by 20-50%. Although profile convexities could be interpreted as a transient response to an increase in rock uplift rate associated with slip on the range-bounding fault, geologic constraints on the initiation of fault slip and the magnitude of displacement cannot be reconciled with a recent, spatially uniform increase in slip rate. Rather, we find that knickzone position, stream profile gradients, and basin averaged erosion rates are best explained by a relatively abrupt spatial increase in uplift rate localized above a flat-ramp transition in the fault system. These analyses highlight the importance of considering spatially non-uniform uplift in the interpretation of stream profile evolution and demonstrate that the adjustment of river profiles to fault displacement can provide constraints on fault geometry in actively eroding landscapes.

Regalla, Christine; Kirby, Eric; Fisher, Donald; Bierman, Paul

2013-08-01

184

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

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

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

2013-12-01

185

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

E-print Network

of the convergence between India and Asia. In Yunnan and Sichuan, for instance, the Ailao Shan^Red River shear zone the edge of the Tarim, the Altyn Tagh fault also ap- pears to cut the lithosphere (e.g. [3]) and contrib

Lacassin, Robin

186

The geometry of the active strike-slip El Tigre Fault, Precordillera of San Juan, Central-Western Argentina: integrating resistivity surveys with structural and geomorphological data  

NASA Astrophysics Data System (ADS)

The geometry and related geomorphological features of the right-lateral strike-slip El Tigre Fault, one of the main morphostructural discontinuities in the Central-Western Precordillera of Argentina, were investigated. Achievements of this survey include: recognition of structural and geometrical discontinuities along the fault trace, identification and classification of landforms associated with local transpressional and transtensional sectors, observation of significant changes in the fault strike and detection of right and left bends of different wavelength. In the Central Segment of the El Tigre Fault, 2D electrical resistivity tomography surveys were carried out across the fault zone. The resistivity imaging permitted to infer the orientation of the main fault surface, the presence of blind fault branches along the fault zone, tectonic tilting of the Quaternary sedimentary cover, subsurface structure of pressure ridges and depth to the water table. Based on this information, it is possible to characterize the El Tigre Fault also as an important hydro-geological barrier. Our survey shows that the main fault surface changes along different segments from a high-angle to a subvertical setting whilst the vertical-slip component is either reverse or normal, depending on the local transpressive or transtensive regime induced by major bends along the trace. These local variations are expressed as sections of a few kilometres in length with relatively homogeneous behaviour and frequently separated by oblique or transversal structures.

Fazzito, Sabrina Y.; Cortés, José M.; Rapalini, Augusto E.; Terrizzano, Carla M.

2013-07-01

187

Geometry  

NSDL National Science Digital Library

Shapes, lines, and more! Here are some fun games to practice geometry and not get bored! Here\\'s a review to help you through the fun... Identify Geometric Shapes and then you will be on your way! After you have reviewed...show me all you know with this Shape Quiz and then all the fun begins!!! Is it a polygon or not? You tell me. Drag them into the bins and we will see! ...

Walker, Ms.

2008-03-31

188

Geometry  

NSDL National Science Digital Library

We are going to review and sharpen our geometry skills with these fun activities and websites! This game is similar to memory. Practice making making matches with this fun memory game. Match the shape to its definition! Think back to what we have learned and practice identifying geometric shapes and lines by the clues given. This game is timed! Re-arrange the colored pieces given to fit them into the square in ...

Jackson, Ms.

2008-03-24

189

2D-to-3D Photo Rendering for 3D Displays Dario Comanducci  

E-print Network

fast and effective ap- proach to 2D-3D conversion of an image pair for the three- dimensional rendering2D-to-3D Photo Rendering for 3D Displays Dario Comanducci Dip. di Sistemi e Informatica, Univ. di geometry, and an original algorithm for the recovery of 3D visual param- eters from the properties

Martin, Ralph R.

190

Calculating Nuclear Power Plant Vulnerability Using Integrated Geometry and Event/Fault-Tree Models  

SciTech Connect

Since the events of September 11, 2001, the vulnerability of nuclear power plants to terrorist attacks has become a national concern. The results of vulnerability analysis are greatly influenced by the computational approaches used. Standard approximations used in fault-tree analysis are not applicable for attacks, where high component failure probabilities are expected; two methods that do work with high failure probabilities are presented. Different blast modeling approaches can also affect the end results. Modeling the structural details of facility buildings and the geometric layout of components within the buildings is required to yield meaningful results.

Peplow, Douglas E. [Oak Ridge National Laboratory (United States); Sulfredge, C. David [Oak Ridge National Laboratory (United States); Sanders, Robert L. [Oak Ridge National Laboratory (United States); Morris, Robert H. [Oak Ridge National Laboratory (United States); Hann, Todd A. [Defense Threat Reduction Agency (United States)

2004-01-15

191

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)

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.

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

1993-01-01

192

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

NASA Astrophysics Data System (ADS)

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.

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

193

Fab trees for designing complex 3D printable materials  

E-print Network

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 ...

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

2013-01-01

194

The Makerbot: Desktop 3D printing  

E-print Network

The Makerbot: Desktop 3D printing Matthew Roughan School of Mathematical Sciences matthew is Lots of maths hidden in something like 3D printing Geometry and Linear algebra ++ Same math used #12;CNC CNC = Computer Numerical Control CNC machines have been around for a while 3D printers

Roughan, Matthew

195

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)

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.

He, Dengfa; Wu, Xiaozhi; ma, Delong

2014-05-01

196

Direct Measurements of Dust Attenuation in z ~ 1.5 Star-forming Galaxies from 3D-HST: Implications for Dust Geometry and Star Formation Rates  

NASA Astrophysics Data System (ADS)

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 V, H II ) and the integrated dust content (A V, 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 V, H II . First, we stack spectra in bins of A V, star, and find that A V, H II = 1.86 A V, 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 *). We find that on average A V, H 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.

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

2014-06-01

197

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)

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.

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

198

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)

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.

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

2013-12-01

199

Unassisted 3D camera calibration  

NASA Astrophysics Data System (ADS)

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.

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

2012-03-01

200

Applications of water-based magnetic gradiometry to assess the geometry and displacement for concealed faults in the southern Adirondack Mountains, New York, U.S.A  

NASA Astrophysics Data System (ADS)

An integrated magnetic gradiometry and structural analysis was conducted on three lakes in the southern Adirondacks Mountains, New York, in order to develop a geometric and kinematic model for concealed and long lived faults that transect the Proterozoic basement structures, offset Paleozoic strata to the south, and may be associated with the development of the post-Paleozoic cratonic dome (the Adirondack dome). Two lakes occur along the trace of two of the most prominent topographic lineaments that have been proposed to be faults in the southern Adirondack Mountains, and a third lake is located at the apparent fault intersection. Hinkley Lake occurs over the east-west trending lineament that corresponds to the trace of the Prospect fault. Indian Lake resides in a set of north-northeast trending pronounced lineaments that transect an anorthosite-cored structural dome and are inferred to be faults on the NYS geologic map. Piseco Lake is immediately adjacent to the intersection of the two proposed fault zones (Prospect and Indian Lake fault zones). Magnetic surveys were conducted on all three lakes, resulting in anomaly maps. Accompanying two dimensional geologic models for Hinkley and Piseco Lake were produced. At Piseco Lake, field evidence supports a brittle deformation history with sinistral-normal displacement. A similar deformation history is consistent with field data collected at Indian Lake. Correlation of the two dimensional magnetic models resulted in a sinistral, releasing-bend fault geometry beneath Piseco Lake, and the fault truncation of a granitic gneiss cored antiform for the subsurface geology of Hinkley Lake. The magnetic data and models suggest that Piseco Lake resides over a sinistral, pull-apart structure with sufficient throw to preserve the lowermost Paleozoic strata that once covered much of the Adirondack dome. This would account for both sinistral strike-slip and normal displacement on the interpreted faults, at Piseco and Indian Lakes, and rotation of structural blocks as the result of fault interaction. Relative timing, regional relationships, and ties to published ages suggest that the distribution of the faults is a relic of Neoproterozoic Iapetan rifting, Paleozoic displacement, and Mesozoic uplift of the Adirondack dome. Finally there is probable correlation of these faults with modern seismic activity.

Valentino, David W.; Chiarenzelli, Jeffrey R.; Hewitt, Elise M.; Valentino, Joshua D.

2012-01-01

201

Fault Separation Gestures  

NSDL National Science Digital Library

Students explore the relationship between fault slip direction and fault separation by varying the geometry of faulted layers, slip direction, and the perspective from which these are viewed. They work in teams to explore these complex geometric relationships via gestures.

Ormand, Carol

202

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

USGS Publications Warehouse

The Mw 7.4 17 August 1999 I??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 Akyaz?? in the east. The SFS emerges from Lake Sapanca as two distinct fault traces that rejoin to traverse the Adapazar?? Plain to Akyaz??. 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 I??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 Kazanc?? to the N75??W, 6-km-long Akyaz?? strand, where slip drops to less than 1 m. The Akyaz?? strand passes eastward into the Akyaz?? 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 I??zmit, Du??zce, 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.

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

203

Coulomb stress accumulation along the San Andreas Fault system  

Microsoft Academic Search

Stress accumulation rates along the primary segments of the San Andreas Fault system are computed using a three-dimensional (3-D) elastic half-space model with realistic fault geometry. The model is developed in the Fourier domain by solving for the response of an elastic half-space due to a point vector body force and analytically integrating the force from a locking depth to

Bridget Smith; David Sandwell

2003-01-01

204

PIXIE3D: A Parallel, Implicit, eXtended MHD 3D Code  

Microsoft Academic Search

We report on the development of PIXIE3D, a 3D parallel, fully implicit Newton-Krylov extended MHD code in general curvilinear geometry. PIXIE3D employs a second-order, finite-volume-based spatial discretization that satisfies remarkable properties such as being conservative, solenoidal in the magnetic field to machine precision, non-dissipative, and linearly and nonlinearly stable in the absence of physical dissipation. PIXIE3D employs fully-implicit Newton-Krylov methods

Luis Chacon

2006-01-01

205

Teaching about Plate Tectonics and Faulting Using Foam Models  

NSDL National Science Digital Library

This demonstration of plate tectonic principles, plate boundary interactions, and the geometry and relative motions of faulting of geologic layers uses 3-D foam models. The models aid in visualization and understanding of plate motions and faulting because they are three-dimensional, concrete rather than abstract descriptions or diagrams, can be manipulated by the instructor and the students, and can show the motions of the plates and faults through time in addition to the three-dimensional configuration of the plates or layers. The models illustrate relatively simple motions and geologic structures, including faulting and plate boundaries, compressional motion and resulting reverse (also called thrust) faults, horizontal slip or strike-slip fault motion, slip or strike-slip fault motion, transform or strike-slip plate boundaries, and elastic rebound.

Braile, Larry

206

Megathrust splay fault geometry and uplift history along the western margin of the subducted Yakutat Terrane, Prince William Sound, Alaska  

NASA Astrophysics Data System (ADS)

High resolution sparker and crustal-scale airgun seismic reflection data, coupled with repeat bathymetric surveys, document the fault distribution and Holocene uplift history across the western edge of the subducted Yakutat terrane, western Prince William Sound, Alaska. Vintage and modern bathymetric surveys suggest that uplift related to the 1964 earthquake was focused along a series of approximately margin-parallel faults that extend from the Alaska mainland south across Prince William Sound into the Gulf of Alaska. Bathymetric surveys indicate that the greatest uplift from the 1964 earthquake was offshore and along strike of the Patton Bay fault that ruptured on Montague Island. Additionally, we document significant uplifts from the 1964 earthquake along parallel faults both landward and seaward of the Patton Bay fault. Sparker seismic reflection data document the post-glacial deposition/tectonic history and suggest out of sequence faulting, active splay faults beneath the Alaska mainland, and active faults that span Prince William Sound and adjacent Gulf of Alaska. Crustal seismic data show these megathrust splay faults separately root into a mid-crustal decollement that defines the top of the seismogenic zone. Faults that splay upward from the decollement correlate with mid-crustal seismic velocity and/or topography changes, with the largest Holocene displacements occurring at the southern margin of the subducted Yakutat terrane. Our new observations place constraints on local tsunami and earthquake sources and suggest changing mid-crustal lithologies play a strong role in splay fault formation. Although the greatest surface ruptures from Holocene earthquakes have been focused around Montague Island, splay faults that offset the sea floor beneath Prince William Sound, the Gulf of Alaska, and the Alaska mainland may be activated during the next large earthquake.

Liberty, L. M.; Finn, S.; Peterson, A. D.; Haeussler, P. J.; Pratt, T. L.

2012-12-01

207

Implications for Fault and Basin Geometry in the Central California Coast Ranges from Preliminary Gravity and Magnetic Data  

NASA Astrophysics Data System (ADS)

Preliminary aeromagnetic and newly processed gravity data help define block-bounding faults and deep sedimentary basins in the central California Coast Ranges, ranging from the Hosgri fault east to the San Andreas fault and from Monterey Bay south to Pt. Conception. Interpretation of these data results in an improved framework for seismic hazard and groundwater studies. Aeromagnetic data include a new survey with a flight-line spacing of 800 m at a nominal 300 m above ground and covering 15,000 km2. More than 11,500 gravity measurements, reprocessed with terrain corrections calculated from 30-m DEMs, form a roughly 2-km grid over most of the study area. Combined potential-field data and existing geologic mapping, delineate major fault-bounded blocks in the central California Coast Ranges. Main block-bounding faults from west to east include the San Gregorio- Hosgri, San Luis-Willmar-Santa Maria River-Little Pine, Oceanic-West Huasna, Nacimiento, Rinconada-South Cuyama, San Juan-Chimineas-Morales, and San Andreas faults. Most of these faults have evidence of Quaternary activity. Gravity gradients indicate that the reach of the San Andreas fault bounding the Gabilan Range and the northern extension of the Rinconada fault bounding the Santa Lucia Range dip steeply southwestward and have a reverse component of slip. Magnetic and microseismicity data suggest that the northern reach of the Hosgri fault dips eastward. The potential-field data also delineate several deep sedimentary basins, such as the 3-4 km deep Cuyama basin, the Santa Maria basin, and several basins along and possibly offset by the Rinconada fault. Gravity data show that the main west-northwest-striking faults bounding the Cuyama basin dip away from the basin, indicating compression adjacent to the big bend in the San Andreas fault. Prominent gravity and magnetic highs northeast of the San Andreas fault immediately east of Cuyama Valley suggest that there the San Andreas fault dips southwest. Such dip information is important for estimating shaking potential of scenario earthquakes and for calculating geodetic deformation whereas basin shapes and fault locations are critical components for groundwater flow modeling.

Langenheim, V. E.; Jachens, R. C.; Graymer, R. W.; Wentworth, C. M.

2008-12-01

208

Europeana and 3D  

NASA Astrophysics Data System (ADS)

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.

Pletinckx, D.

2011-09-01

209

Supracrustal faults of the St. Lawrence rift system, Québec: kinematics and geometry as revealed by field mapping and marine seismic reflection data  

NASA Astrophysics Data System (ADS)

The St. Lawrence rift system from the Laurentian craton core to the offshore St. Lawrence River system is a seismically active zone in which fault reactivation is believed to occur along late Proterozoic to early Paleozoic normal faults related to the opening of the Iapetus ocean. The rift-related faults fringe the contact between the Grenvillian basement to the NW and Cambrian-Ordovician rocks of the St. Lawrence Lowlands to the SE and occur also within the Grenvillian basement. The St. Lawrence rift system trends NE-SW and represents a SE-dipping half-graben that links the NW-SE-trending Ottawa-Bonnechère and Saguenay River grabens, both interpreted as Iapetan failed arms. Coastal sections of the St. Lawrence River that expose fault rocks related to the St. Lawrence rift system have been studied between Québec city and the Saguenay River. Brittle faults marking the St. Lawrence rift system consist of NE- and NW-trending structures that show mutual crosscutting relationships. Fault rocks consist of fault breccias, cataclasites and pseudotachylytes. Field relationships suggest that the various types of fault rocks are associated with the same tectonic event. High-resolution marine seismic reflection data acquired in the St. Lawrence River estuary, between Rimouski, the Saguenay River and Forestville, identify submarine topographic relief attributed to the St. Lawrence rift system. Northeast-trending seismic reflection profiles show a basement geometry that agrees with onshore structural features. Northwest-trending seismic profiles suggest that normal faults fringing the St. Lawrence River are associated with a major topographic depression in the estuary, the Laurentian Channel trough, with up to 700 m of basement relief. A two-way travel-time to bedrock map, based on seismic data from the St. Lawrence estuary, and comparison with the onshore rift segment suggest that the Laurentian Channel trough varies from a half-graben to a graben structure from SW to NE. It is speculated that natural gas occurrences within both the onshore and offshore sequences of unconsolidated Quaternary deposits are possibly related to degassing processes of basement rocks, and that hydrocarbons were drained upward by the rift faults.

Tremblay, Alain; Long, Bernard; Massé, Manon

2003-07-01

210

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

NASA Astrophysics Data System (ADS)

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.

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

2012-11-01

211

3-D seismology in the Arabian Gulf  

SciTech Connect

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.

Al-Husseini, M. [Gulf PetroLink, Manama (Bahrain); Chimblo, R. [Saudi Aramco, Dhahran (Saudi Arabia)

1995-08-01

212

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

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 ?? 10 18 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.

Wright, T. J.; Lu, Z.; Wicks, C.

2004-01-01

213

Fault Geometry and Active Stress from Earthquakes and Field Geology Data Analysis: The Colfiorito 1997 and L'Aquila 2009 Cases (Central Italy)  

NASA Astrophysics Data System (ADS)

The fault segmentation pattern and the regional stress tensor acting since the Early Quaternary in the intra-Apennine area of central Italy was constrained by integrating two large geological and seismological fault-slip data sets collected for the areas struck by the two most energetic seismic sequences of the last 15 years (Colfiorito 1997, M w 6.0 and L'Aquila 2009, M w 6.1). The integrated analysis of the earthquake fault association and the reconstruction of the 3D shape of the seismogenic sources were exploited to identify homogeneous seismogenic volumes associated with subsets of geological and focal mechanism data. The independent analysis of geological and seismological data allowed us to observe and highlight similarities between the attitude of the long-term (e.g., Quaternary) and the instantaneous present-day (seismogenic) extensional deformations and to reveal their substantial coaxiality. Coherently, with the results from the kinematic analysis, the stress field inversion also noted a prevailing tensional seismotectonic regime associated with a subhorizontal, NE-SW, minimum stress axis. A minor, very local, and shallow (<5 km) strike-slip component of the stress field was observed in the Colfiorito sector, where an inherited N-S oriented right-lateral fault was reactivated with sinistral kinematics. Instead, an almost total absence of strike-slip solutions was observed in the L'Aquila area. These results do not agree with those indicating Quaternary regional strike-slip regimes or wide areas characterized by strike-slip deformation during the Colfiorito and L'Aquila seismic sequences.

Ferrarini, F.; Lavecchia, G.; de Nardis, R.; Brozzetti, F.

2014-09-01

214

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

NASA Astrophysics Data System (ADS)

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.

Lue, James; Schulze, Jürgen P.

2014-02-01

215

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

NASA Astrophysics Data System (ADS)

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.

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

2014-08-01

216

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

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.

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

2003-01-01

217

3D Imaging.  

ERIC Educational Resources Information Center

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)

Hastings, S. K.

2002-01-01

218

3D Shapes Video  

NSDL National Science Digital Library

This upbeat music video reviews 3D shapes including the sphere, cylinder, cube, and cone. As each 3D shape is presented, examples of things we see every day that have the same shape are also shown for reinforcement. (Length: 3:18)

Kindergarten, Harry

2011-06-17

219

3D Slicer  

Microsoft Academic Search

To be applied to practical clinical research problems, medical image computing software requires infrastructure including routines to read and write various file formats, manipulate 2D and 3D coordinate systems, and present a consistent user interface paradigm and visualization metaphor. At the same time, research software needs to be flexible to facilitate implementation of new ideas. 3D Slicer is a project

Stephen D. Pieper; Michael Halle; Ron Kikinis

2004-01-01

220

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

E-print Network

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" ...

Glover, Jared Marshall

2014-01-01

221

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

SciTech Connect

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.

Gao, Dengliang

2013-03-01

222

Terajets produced by 3D dielectric cuboids  

E-print Network

The capability of generating terajets using 3D dielectric cuboids working at terahertz (THz) frequencies (as analogues of nanojets in the infrared band) are introduced and studied numerically. The focusing performance of the terajets are evaluated in terms of the transversal full width at half maximum along x- and y- directions using different refractive indexes for a 3D dielectric cuboid with a fixed geometry, obtaining a quasi-symmetric terajet with a subwavelength resolution of ~0.46{\\lambda}0 when the refractive index is n = 1.41. Moreover, the backscattering enhancement produced when metal particles are introduced in the terajet region is demonstrated for a 3D dielectric cuboid and compared with its 2D counterpart. The results of the jet generated for the 3D case are experimentally validated at sub-THz waves, demonstrating the ability to produce terajets using 3D cuboids.

Pacheco-Peña, V; Minin, I V; Minin, O V

2014-01-01

223

An Improved Version of TOPAZ 3D  

SciTech Connect

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.

Krasnykh, Anatoly

2003-07-29

224

AN IMPROVED VERSION OF TOPAZ 3D *  

E-print Network

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.

unknown authors

2003-01-01

225

A support-operator method for 3-D rupture dynamics  

NASA Astrophysics Data System (ADS)

We present a numerical method to simulate spontaneous shear crack propagation within a heterogeneous, 3-D, viscoelastic medium. Wave motions are computed on a logically rectangular hexahedral mesh, using the generalized finite-difference method of Support Operators (SOM). This approach enables modelling of non-planar surfaces and non-planar fault ruptures. Our implementation, the Support Operator Rupture Dynamics (SORD) code, is highly scalable, enabling large-scale, multiprocessors calculations. The fault surface is modelled by coupled double nodes, where rupture occurs as dictated by the local stress conditions and a frictional failure law. The method successfully performs test problems developed for the Southern California Earthquake Center (SCEC)/U.S. Geological Survey (USGS) dynamic earthquake rupture code validation exercise, showing good agreement with semi-analytical boundary integral method results. We undertake further dynamic rupture tests to quantify numerical errors introduced by shear deformations to the hexahedral mesh. We generate a family of meshes distorted by simple shearing, in the along-strike direction, up to a maximum of 73°. For SCEC/USGS validation problem number 3, grid-induced errors increase with mesh shear angle, with the logarithm of error approximately proportional to angle over the range tested. At 73°, rms misfits are about 10 per cent for peak slip rate, and 0.5 per cent for both rupture time and total slip, indicating that the method (which, up to now, we have applied mainly to near-vertical strike-slip faulting) is also capable of handling geometries appropriate to low-angle surface-rupturing thrust earthquakes. Additionally, we demonstrate non-planar rupture effects, by modifying the test geometry to include, respectively, cylindrical curvature and sharp kinks.

Ely, Geoffrey P.; Day, Steven M.; Minster, Jean-Bernard

2009-06-01

226

Re-evaluation of fault geometry and slip distribution of surface ruptures associated with the large earthquakes in the 20th century along the central and eastern part of the North Anatolian fault system  

NASA Astrophysics Data System (ADS)

The North Anatolian Fault System (NAFS) which is a seismically active continental plate boundary transform system ruptured in a westward-migrating sequence of large earthquakes between 1939 and 1999. 1939, 1942 and 1943 earthquakes occurred on the eastern and central NAFS in this sequence. The 1939 (M:7.9) and 1943 (M7.6) earthqaukes which are largest two events in the sequence produced multi-segment surface ruptures 380 and 280 km-long, respectively. The 1942 (M7.0) earthquake generated from Erbaa-Niksar fault located between these two multi-segment ruptures formed a 48 km-long surface rupture. We have performed a serial study on the fault geometry and revision of slip data associated with these earthquakes based on detailed field mapping of the ruptures and interview to local eyewitness. The 1939 Erzincan earthquake which is the largest event in the sequence nucleated on a restraining bend close the eastern end. The rupture extended along the master strand of the NAFS between Erzincan and Niksar basins. However, a part of 65 km-long western portion of the rupture directed towards on the Ezinepazar? splay fault. Along the 1939 rupture, on going studies reveal that the slip is not uniform along fault strike and the amount of slip varies between 1 to 8 m. The 1943 earthquake which is second largest event along the NAFS in 20th century nucleated on the western end of the rupture and unilaterally propagated eastward contrary to the 1939 event. The 1943 rupture is divided into nine sub-segments based on slip distribution and fault jogs. The amount of average slip along the entire rupture zone is 3.6 m. and the maximum slip of 6.0 m. These newly measured amounts of slip are larger than previously reported. A 48-km-long surface rupture was formed in the 1942 earthquake. The surface rupture associated with this earthquake is divided into two main sections by a 12 km-long restraining stepover which is characterized with a push-up structure bounding reverse faults. The event nucleated below this restraining stepover and bilaterally propagated. The amount of the maximum slip riches up 2.5 m along the rupture zone. The data conclude that: 1) the 1939 and 1943 multi-segment earthqaukes on the central and eastern NAFS nucleated on the large restraining bends and propagated unilaterally, 2) not only Niksar releasing stepover but also structural complexity in the Erbaa-Niksar region played a significant role on the deviating of the 1939 rupture from the master strand to the Ezinepazar? splay, 3) in general, the direction of the fault along each multi-segment rupture changes near or on the restraining bends or stepovers as well as along the entirety of the fault zone 4) the average slip along multi-segment ruptures is not uniform, and the amounts of the measured slip in this study along the central and eastern NAFS is larger than that of previous study, 5) In comparison with the slip distribution on the surface ruptures between the 1939 and 1999 earthquakes, the average slip along the entire NAFS is rather uniform and diminish gradually westward except for eastern portion of the 1939 rupture.

Emre, O.; Kondo, H.; Kurcer, A.; Ozalp, S.

2009-04-01

227

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

USGS Publications Warehouse

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.

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

2014-01-01

228

Google Maps 3D  

NSDL National Science Digital Library

Several major companies, including Google, are working on getting elaborate 3D maps online. This latest iteration of Google maps for Android-powered devices allows users to browse select cities in a 3D fashion. Utilizing aerial imagery, the buildings appear in a three-dimensional format, which can aid people navigating their way around an unfamiliar urban environment. Visitors can customize their own views with the "tilt" and "compass" mode features, which makes things a bit more fun.

2012-07-20

229

TRACE 3-D documentation  

SciTech Connect

TRACE 3-D is an interactive beam-dynamics program that calculates the envelopes of a bunched beam, including linear space-charge forces, through a user-defined transport system. TRACE 3-D provides an immediate graphics display of the envelopes and the phase-space ellipses and allows nine types of beam-matching options. This report describes the beam-dynamics calculations and gives detailed instruction for using the code. Several examples are described in detail.

Crandall, K.R.

1987-08-01

230

3-D Simulations  

NSDL National Science Digital Library

Three-dimensional (3-D) rendering and animation technology is not only used for entertainment, but also for research and educational purposes. The technology can be used for purposes of scientific simulation in fields such as physics, biology, or chemistry. For example, Stanford University's Folding@home project (1) uses 3-D simulations and distributed computing to study protein folding, misfolding, aggregation, and related diseases. Three-D simulations can also be used to observe phenomena that would normally be impossible to scrutinize in detail, as is demonstrated on this website on Nanorobotics (2). This next website describes work by the Robotics Research Group (3) in using 3-D simulations to enhance undergraduate and graduate engineering education. The EdCenter (4) makes available several compressed files of 3-D simulations that model earthquake data, Mars, a San Diego Fly Through, and more. On this website (5 ), Martin Baker provides "all you need to know about 3D theory" and this website (6) provides access to a free open-source software package which "makes it easy to build 3-D simulations of decentralized systems and artificial life." This last article from Cyberbotics, Ltd. (7) discusses how mobile robotics simulation programs can be used to design robots.

231

2003), Coulomb stress accumulation along the San Andreas Fault system  

E-print Network

[1] Stress accumulation rates along the primary segments of the San Andreas Fault system are computed using a three-dimensional (3-D) elastic half-space model with realistic fault geometry. The model is developed in the Fourier domain by solving for the response of an elastic half-space due to a point vector body force and analytically integrating the force from a locking depth to infinite depth. This approach is then applied to the San Andreas Fault system using published slip rates along 18 major fault strands of the fault zone. GPS-derived horizontal velocity measurements spanning the entire 1700 200 km region are then used to solve for apparent locking depth along each primary fault segment. This simple model fits remarkably well (2.43 mm/yr RMS misfit), although some discrepancies occur in the Eastern California Shear Zone. The model also predicts vertical uplift and subsidence rates that are in agreement with independent geologic and geodetic estimates. In addition, shear and normal stresses along the major fault strands are used to compute Coulomb stress accumulation rate. As a result, we find earthquake recurrence intervals along the San Andreas Fault system to be inversely proportional to Coulomb stress accumulation rate, in agreement with typical coseismic stress drops of 1–10 MPa. This 3-D deformation model can ultimately be extended to include both time-dependent forcing and viscoelastic response.

Bridget Smith; David S

232

Coulomb Stress Accumulation along the San Andreas Fault System  

NASA Technical Reports Server (NTRS)

Stress accumulation rates along the primary segments of the San Andreas Fault system are computed using a three-dimensional (3-D) elastic half-space model with realistic fault geometry. The model is developed in the Fourier domain by solving for the response of an elastic half-space due to a point vector body force and analytically integrating the force from a locking depth to infinite depth. This approach is then applied to the San Andreas Fault system using published slip rates along 18 major fault strands of the fault zone. GPS-derived horizontal velocity measurements spanning the entire 1700 x 200 km region are then used to solve for apparent locking depth along each primary fault segment. This simple model fits remarkably well (2.43 mm/yr RMS misfit), although some discrepancies occur in the Eastern California Shear Zone. The model also predicts vertical uplift and subsidence rates that are in agreement with independent geologic and geodetic estimates. In addition, shear and normal stresses along the major fault strands are used to compute Coulomb stress accumulation rate. As a result, we find earthquake recurrence intervals along the San Andreas Fault system to be inversely proportional to Coulomb stress accumulation rate, in agreement with typical coseismic stress drops of 1 - 10 MPa. This 3-D deformation model can ultimately be extended to include both time-dependent forcing and viscoelastic response.

Smith, Bridget; Sandwell, David

2003-01-01

233

3D Magnetron simulation with CST STUDIO SUITE  

SciTech Connect

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)

Balk, Monika C., E-mail: monika.balk@cst.com [CST AG, Bad Nauheimerstr. 19, 64289 Darmstadt (Germany)

2011-07-01

234

OSP 3D Eclipse Workspace  

NSDL National Science Digital Library

The OSP 3D Eclipse Workspace contains the source code and examples for the Simple 3D and Java 3D implementations of OSP 3D API. The Simple 3D implementation uses only the standard Java distribution and will run on any Java-enabled computer. The Java 3D implementation improves the performance and the appearance of examples but the Java 3D library must be installed. Like the Simple 3D implementation, the Java 3D implementation uses GPU hardware acceleration to provide better intersection of surfaces and hidden-lines removal, as well as additional features such as textures and lighting. See Java 3D.

Jara, Carlos; Franciscouembre; Christian, Wolfgang

2011-04-05

235

Self-Discovery of Structural Geology Concepts using Interactive 3D Visualization  

NASA Astrophysics Data System (ADS)

Mastering structural geology concepts that depend on understanding three-dimensional (3D) geometries and imagining relationships among unseen subsurface structures are fundamental skills for geologists. Traditionally these skills are developed first, through use of 2D drawings of 3D structures that can be difficult to decipher or 3D physical block models that show only a limited set of relationships on the surfaces of the blocks, followed by application and testing of concepts in field settings. We hypothesize that this learning process can be improved by providing repeated opportunities to evaluate and explore synthetic 3D structures using interactive 3D visualization software. We present laboratory modules designed for undergraduate structural geology curriculum using a self-discovery approach to teach concepts such as: the Rule of V’s, structure separation versus fault slip, and the more general dependence of structural exposure on surface topography. The laboratory modules are structured to allow students to discover and articulate each concept from observations of synthetic data both on traditional maps and using the volume visualization software 3DVisualizer. Modules lead students through exploration of data (e.g., a dipping layered structure exposed in ridge-valley topography or obliquely offset across a fault) by allowing them to interactively view (rotate, pan, zoom) the exposure of structures on topographic surfaces and to toggle on/off the full 3D structure as a transparent colored volume. This tool allows student to easily visually understand the relationships between, for example a dipping structure and its exposure on valley walls, as well as how the structure extends beneath the surface. Using this method gives students more opportunities to build a mental library of previously-seen relationships from which to draw-on when applying concepts in the field setting. These laboratory modules, the data and software are freely available from KeckCAVES.

Billen, M. I.; Saunders, J.

2010-12-01

236

3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

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

Zhu, Zhigang

237

3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

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

Zhu, Zhigang

238

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

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

239

Photogrammetry and 3D city modeling Y. Kobayashi, Ph.D.  

E-print Network

approach is to create 3D objects one by one with the support of technologies like photogrammetry and 3D software packages that are commercially available such as 3D Studio Max and Maya. Spine3D [4] #12;is one are the technologies commonly used in extracting 3D geometries. The LiDAR instrument transmits light to a target

240

Magmatic Systems in 3-D  

NASA Astrophysics Data System (ADS)

Multichannel seismic (MCS) images of crustal magma chambers are ideal targets for advanced visualization techniques. In the mid-ocean ridge environment, reflections originating at the melt-lens are well separated from other reflection boundaries, such as the seafloor, layer 2A and Moho, which enables the effective use of transparency filters. 3-D visualization of seismic reflectivity falls into two broad categories: volume and surface rendering. Volumetric-based visualization is an extremely powerful approach for the rapid exploration of very dense 3-D datasets. These 3-D datasets are divided into volume elements or voxels, which are individually color coded depending on the assigned datum value; the user can define an opacity filter to reject plotting certain voxels. This transparency allows the user to peer into the data volume, enabling an easy identification of patterns or relationships that might have geologic merit. Multiple image volumes can be co-registered to look at correlations between two different data types (e.g., amplitude variation with offsets studies), in a manner analogous to draping attributes onto a surface. In contrast, surface visualization of seismic reflectivity usually involves producing "fence" diagrams of 2-D seismic profiles that are complemented with seafloor topography, along with point class data, draped lines and vectors (e.g. fault scarps, earthquake locations and plate-motions). The overlying seafloor can be made partially transparent or see-through, enabling 3-D correlations between seafloor structure and seismic reflectivity. Exploration of 3-D datasets requires additional thought when constructing and manipulating these complex objects. As numbers of visual objects grow in a particular scene, there is a tendency to mask overlapping objects; this clutter can be managed through the effective use of total or partial transparency (i.e., alpha-channel). In this way, the co-variation between different datasets can be investigated, even if one data object lies behind another. Stereoscopic viewing is another powerful tool to investigate 3-D relationships between objects. This form of immersion is constructed through viewing two separate images that are interleaved--typically 48 frames per second, per eye--and synced through an emitter and a set of specialized polarizing eyeglasses. The polarizing lenses flicker at an equivalent rate, blanking the eye for which a particular image was not drawn, producing the desired stereo effect. Volumetric visualization of the ARAD 3-D seismic dataset will be presented. The effective use of transparency reveals detailed structure of the melt-lens beneath the 9°03'N overlapping spreading center (OSC) along the East Pacific Rise, including melt-filled fractures within the propagating rift-tip. In addition, range-gated images of seismic reflectivity will be co-registered to investigate the physical properties (melt versus mush) of the magma chamber at this locale. Surface visualization of a dense, 2-D grid of MCS seismic data beneath Axial seamount (Juan de Fuca Ridge) will also be highlighted, including relationships between the summit caldera and rift zones, and the underlying (and humongous) magma chamber. A selection of Quicktime movies will be shown. Popcorn will be served, really!

Kent, G. M.; Harding, A. J.; Babcock, J. M.; Orcutt, J. A.; Bazin, S.; Singh, S.; Detrick, R. S.; Canales, J. P.; Carbotte, S. M.; Diebold, J.

2002-12-01

241

Modeling fault kinematics, segment interaction and transfer zone geometry as a function of pre-existing fabrics: the Albertine rift, East African Rift System.  

NASA Astrophysics Data System (ADS)

This study focuses on the development of the Rwenzori Mountains, an uplift horst block within the northern-most segment of the western branch of the East African Rift System (EARS). Attention is drawn to the role of pre-existing crustal weaknesses left behind by Proterozoic mobile belts that pass around cratonic Archean shields namely the Tanzanian Craton to the southeast and the Congo craton to the northwest. We study how the southward propagating sub-segment of the rift that contains Lake Albert to the north interacts with the northward propagating sub-segment that contains the lakes Edward and George and how this interaction produces the structural geometries observed within and around the Rwenzori horst block. Analogue experiments are used to simulate behavior of the upper crust with pre-cut rubber strips of varying overstep/overlap, placed oblique and/or orthogonal to the extension vector. The points of connection to the basal sheet present velocity discontinuities to localize deformation below the sand. Surface geometry of the developing rifts and section cuts are used to study the kinematics that result from the given boundary conditions. In general we try to model two parallel rifts that propagate towards each other and interact. Results show that greater overstep of rifts produces an oblique shear-dominated transfer zone with deep grabens (max.7.0km) in the adjoining segments. Smaller overlap ends in extension-dominated transfer, offset rift segments without oblique transfer faults to join two adjacent rift arms and produces moderately deep grabens (max.4.6km). When overlap doubles the overstep (SbR5), rifts propagate sub-orthogonal to the extension direction in a rotation-dominated transfer and form shallow valleys (max.2.9km). Whether a block like the Rwenzori Mountains is captured and rotates, depends on the overlap/overstep ratio where the rotation direction of a captured block is determined by the sense of overlap (right- or left-lateral). Fault orientation, fault kinematics and block rotation (once in play) re-enforce each other, and depending on the local kinematics different parts of a captured block can be rotated by different amounts but in the same general direction. The results are compared with the natural scenario. Keywords: Albertine rift; Analogue; Extension; Kinematics; Transfer zone

Aanyu, Kevin; Koehn, Daniel

2010-05-01

242

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

NASA Astrophysics Data System (ADS)

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.

Gusev, A. A.

2013-01-01

243

Lenticular Sheet 3-D Pictures And 3-D Projections  

NASA Astrophysics Data System (ADS)

The concept of lenticular sheet 3-D pictures dates from the beginning of this century. This method is responsible of commercial 3-D post-cards and 3-D photographic portraits. New applications are presented in this paper. They concern two domains where direct holographic 3-D reconstructions are impossible. These applications are the 3-D reconstruction of electron microscope pictures and the 3-D projection on a lenticular screen.

Marraud, A.; Bonnet, M.; Rambourg, A.

1980-06-01

244

Pinnacles National Monument: A 3-D Tour Featuring Park Geology  

NSDL National Science Digital Library

This virtual tour features three-dimensional images from the United States Geological Survey's (USGS) collection. It introduces visitors to the geology and landforms of Pinnacles National Monument in California, the location of a belt of Tertiary volcanic rocks (tuff, breccia, and ash of rhyolite, dacite, and andesite composition). The location of the Pinnacles volcanic area near the San Andreas Fault has important implications for deciphering the geologic history of the fault system. Views include the trace of the San Andreas fault and erosional features (pinnacles, caves, cliffs, etc.) carved into the volcanic deposits. The 3-D images are anaglyphs and require red and cyan 3-D viewing glasses.

245

3D reservoir visualization  

SciTech Connect

This paper shows how some simple 3D computer graphics tools can be combined to provide efficient software for visualizing and analyzing data obtained from reservoir simulators and geological simulations. The animation and interactive capabilities of the software quickly provide a deep understanding of the fluid-flow behavior and an accurate idea of the internal architecture of a reservoir.

Van, B.T.; Pajon, J.L.; Joseph, P. (Inst. Francais du Petrole (FR))

1991-11-01

246

3D Face Identification  

Microsoft Academic Search

Technologies related to identity recognition have found widespread application in the last years; among these, face recognition is one of the most promising and probably the most studied. The main goal of this work is to verify if it is possible to obtain a reliable identification of people, starting from a reconstructed 3D model of the face images. We describe

Mosad Abdelwahab; Abd El-hamid; H. El-bakry; M. A. El-dosuky

2014-01-01

247

Aura 3D Textures  

Microsoft Academic Search

This paper presents a new technique, called aura 3D textures, for generating solid textures based on input examples. Our method is fully automatic and requires no user interactions in the process. Given an input texture sample, our method first creates its aura matrix representations and then generates a solid texture by sampling the aura matrices of the input sample constrained

Xuejie Qin; Yee-hong Yang

2007-01-01

248

Seeing in 3D  

Microsoft Academic Search

Most people, even among technical draftsmen, designers and computer graphics programmers, find it very difficult to visualize 3D shapes well enough to reason about them. We demonstrate the problem and take participants through a series of exercises whereby they can begin to acquire this important practical skill. \\

Bob Parslow; Geoff Wyvill

2008-01-01

249

3D Metrology Camera  

Microsoft Academic Search

We describe a concept for a metrology system that can simultaneously determine the Cartesian coordinates of thousands of targets and has no moving parts. The system is called the MSTAR3D system and is based on two color interferometry where the conventional photodiode has been replaced with an extremely fast focal plane array. It permits the measurement of the three-dimensional position

Carl Christian Liebe; Serge Dubovitsky; Robert Peters

2007-01-01

250

Effect of Near-fault Terrain upon Dislocation Modeling  

Microsoft Academic Search

Coseismic surface deformation provides important information needed to determine source rupture geometry and slip distribution as well as to estimate seismic moment. In this study, numerical experiments were designed to analyze and classify how free-surface topography affects surface deformation. The investigation was performed by 3-D finite element modeling. Results of this study show that crustal deformation induced by near-fault terrain

B.-S. Huang; Y. T. Yeh

1997-01-01

251

3D printed bionic ears.  

PubMed

The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing. PMID:23635097

Mannoor, Manu S; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A; Soboyejo, Winston O; Verma, Naveen; Gracias, David H; McAlpine, Michael C

2013-06-12

252

3D Printed Bionic Ears  

PubMed Central

The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the precise anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing. PMID:23635097

Mannoor, Manu S.; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A.; Soboyejo, Winston O.; Verma, Naveen; Gracias, David H.; McAlpine, Michael C.

2013-01-01

253

The Galicia 3D experiment: an Introduction.  

NASA Astrophysics Data System (ADS)

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.

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

254

Two-dimensional distinct element modeling of the structure and growth of normal faults in multilayer sequences: 2. Impact of confining pressure and strength contrast on fault zone geometry and growth  

Microsoft Academic Search

The growth of normal faults in periodically layered sequences with varying strength contrast and at varying confining pressure is modeled using the distinct element method. The normal faulting models are composed of strong layers (bonded particles) and weak layers (nonbonded particles) that are deformed using a predefined fault at the base of the sequence. The model results suggest that faults

Martin P. J. Schöpfer; Conrad Childs; John J. Walsh

2007-01-01

255

3D Magnetic inversion and remanence: solving the problem  

NASA Astrophysics Data System (ADS)

3D inversion of surface magnetic data is a common processing technique when used in mineral exploration. The major drawback of most 3D inversion algorithms is that they assume that the surface magnetic anomaly is produced by induced magnetization and that there are no remanent magnetization or demagnetization effects present. This has a significant impact when modeling magnetic data that has remanent magnetization. The magnetic anomaly produced by a dipping subsurface body will be identical for a consistent relationship between the dip of the body and the dip of the magnetic vector, regardless of the actual dip of the magnetic body. For example, in the case where a subsurface body is dipping, such as a dipping dike, the dip estimated by the inversion routine will be correct only if induced magnetization is present. This has serious implications for mineral exploration. A solution to the remanence problem is to model the surface magnetic anomaly using a constrained 2D approach rather than 3D. Using a priori information on dip and strike length of a source body, it is possible to approximate the remanence direction and intensity. The 2D solutions can then be rendered into a 3D imaging package to create a model in 3D. A case study was performed on a mafic-ultramafic layered igneous intrusion located in Big Trout Lake, northwestern Ontario, Canada. Large layered igneous intrusions are known to have significant remanence. Like many other layered igneous intrusions such as the Bushveld Complex in South Africa, the Big Trout Lake Complex is highly prospective for Platinum Group Elements (PGEs). Intruded during Archean time, the Big Trout Lake Complex has been subsequently folded and faulted to near vertical. As a consequence of limited surface exposures, knowledge of layering within the pluton and the extent of deformation of the pluton is very limited. Newly acquired high-resolution aeromagnetic data shows a strongly mineralized horizon within the intrusion that corresponds to an enrichment in magnetite and sulfides. By modeling this mineralized layer, the geometry of the intrusion can be interpreted which will lead to a better understanding of the distribution of PGEs within the intrusion. A series of 2D inversions were run, perpendicular to strike, along the mineralized layer of the intrusion using a dipping dike model. Observations showed that a similar remanence direction was calculated for all inversions. When plotted on a stereonet, the average declination was 358° and inclination of 02°. The results from the 2D inversion provided x, y, and z coordinates of the modeled body which were then be brought into a 3D imaging software package. The results of this case study show that it is possible to develop a preliminary 3D model from a series of 2D inversions. This enables integration with other geoscience data sets to improve and validate the model. The geometry estimated by the inversions can now be compared with known information such as topography, geological maps, and borehole lithology and geophysics. Aspects of the model can be refined with new information. The known distribution of ore can be used to establish a genetic model of the mineral deposit. This study also shows that it is possible to estimate the remanence direction and structure of the mineralized layer of the intrusion. Integrating geoscience data can help develop the 3D model by validating data within the model, increasing the accuracy of the model, and further constraining the inversions. This directly applies to the exploration industry because it reduces the exploration risks and also helps to identify new exploration targets.

Thomson, V.; Morris, W.

2003-04-01

256

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

NASA Astrophysics Data System (ADS)

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

Shi, Beiqi; Rui, Jianxun; Chen, Neng

2008-10-01

257

Interactives: 3D Shapes  

NSDL National Science Digital Library

How much liquid can that glass hold? What are the dimensions of that package that's heading off to a friend overseas? Answers to both of those questions (and many more) can be found in this lovely interactive feature on 3D shapes created by experts at the Annenberg Media group. Visitors to this site will learn about three-dimensional geometric shapes by examining a number of objects through a number of interactive exercises and games. The materials are divided into four sections, which include "3D Shapes", "Surface Area & Volume", and "Platonic Solids". The "Platonic Solids" area is quite a bit of fun, as visitors will get the opportunity to print out foldable shapes such as a tetrahedron. A short fifteen question quiz that tests the materials covered by these various activities rounds out the site.

258

Sketching 3D Animations  

Microsoft Academic Search

We are interested in providing animators with a general-purpose tool allowing them to create animations using straight-ahead actions as well as pose-to-pose techniques. Our approach seeks to bring the expressiveness of real-time motion capture systems into a general-purpose multi-track system running on a graphics workstation. We emphasize the use of high-bandwidth interaction with 3D objects together with specific data reduction

Jean-francis Balaguer; Enrico Gobbetti

1995-01-01

259

3D Bridge Construction  

Microsoft Academic Search

In the field of architecture, tangible virtual reality interfaces allow architects to design and construct large complex structures in a three-dimensional space, and interact with the 3D models using the most natural means of computer human interaction: the two-handed system. The main goal of this project is to design and create an interactive, tangible, virtual reality interface for constructing various

Yuan Xie; Peter Schröder; Steven Schkolne

260

3D Flyover Movies  

NSDL National Science Digital Library

This collection of 3D flyover movies depicts geologically interesting localities in the Southwest United States. The selection includes well-known landmarks such as Meteor Crater, Monument Valley, Hopi Buttes, and others. They are available in a number of different formats and file sizes. The movies, the data files used to make them, and the software to view them are all available for free download. There is also a link to a tutorial on how to make Fledermaus scenes and movies.

Simkin, Marvin

2005-01-01

261

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

USGS Publications Warehouse

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.

Barall, M.

2009-01-01

262

Parallel CARLOS-3D code development  

SciTech Connect

CARLOS-3D is a three-dimensional scattering code which was developed under the sponsorship of the Electromagnetic Code Consortium, and is currently used by over 80 aerospace companies and government agencies. The code has been extensively validated and runs on both serial workstations and parallel super computers such as the Intel Paragon. CARLOS-3D is a three-dimensional surface integral equation scattering code based on a Galerkin method of moments formulation employing Rao- Wilton-Glisson roof-top basis for triangular faceted surfaces. Fully arbitrary 3D geometries composed of multiple conducting and homogeneous bulk dielectric materials can be modeled. This presentation describes some of the extensions to the CARLOS-3D code, and how the operator structure of the code facilitated these improvements. Body of revolution (BOR) and two-dimensional geometries were incorporated by simply including new input routines, and the appropriate Galerkin matrix operator routines. Some additional modifications were required in the combined field integral equation matrix generation routine due to the symmetric nature of the BOR and 2D operators. Quadrilateral patched surfaces with linear roof-top basis functions were also implemented in the same manner. Quadrilateral facets and triangular facets can be used in combination to more efficiently model geometries with both large smooth surfaces and surfaces with fine detail such as gaps and cracks. Since the parallel implementation in CARLOS-3D is at high level, these changes were independent of the computer platform being used. This approach minimizes code maintenance, while providing capabilities with little additional effort. Results are presented showing the performance and accuracy of the code for some large scattering problems. Comparisons between triangular faceted and quadrilateral faceted geometry representations will be shown for some complex scatterers.

Putnam, J.M. [McDonnell Douglas Corp., St. Louis, MO (United States); Kotulski, J.D. [Sandia National Labs., Albuquerque, NM (United States)

1996-02-01

263

Fault reactivation control on normal fault growth: an experimental study  

NASA Astrophysics Data System (ADS)

Field studies frequently emphasize how fault reactivation is involved in the deformation of the upper crust. However, this phenomenon is generally neglected (except in inversion models) in analogue and numerical models performed to study fault network growth. Using sand/silicon analogue models, we show how pre-existing discontinuities can control the geometry and evolution of a younger fault network. The models show that the reactivation of pre-existing discontinuities and their orientation control: (i) the evolution of the main fault orientation distribution through time, (ii) the geometry of relay fault zones, (iii) the geometry of small scale faulting, and (iv) the geometry and location of fault-controlled basins and depocenters. These results are in good agreement with natural fault networks observed in both the Gulf of Suez and Lake Tanganyika. They demonstrate that heterogeneities such as pre-existing faults should be included in models designed to understand the behavior and the tectonic evolution of sedimentary basins.

Bellahsen, Nicolas; Daniel, Jean Marc

2005-04-01

264

3D Model of the Neal Hot Springs Geothermal Area  

DOE Data Explorer

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.

James E. Faulds

265

3D Audio System  

NASA Technical Reports Server (NTRS)

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.

1992-01-01

266

3D and beyond  

NASA Astrophysics Data System (ADS)

This conference on physiology and function covers a wide range of subjects, including the vasculature and blood flow, the flow of gas, water, and blood in the lung, the neurological structure and function, the modeling, and the motion and mechanics of organs. Many technologies are discussed. I believe that the list would include a robotic photographer, to hold the optical equipment in a precisely controlled way to obtain the images for the user. Why are 3D images needed? They are to achieve certain objectives through measurements of some objects. For example, in order to improve performance in sports or beauty of a person, we measure the form, dimensions, appearance, and movements.

Fung, Y. C.

1995-05-01

267

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

SciTech Connect

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.

Kanu, K.A.; Glass, J.E.; Okoro, P.C. [Chevron Nigeria Ltd., Lagos (Nigeria)] [and others

1995-08-01

268

3D Surgical Simulation  

PubMed Central

This paper discusses the development of methods for computer-aided jaw surgery. Computer-aided jaw surgery allows us to incorporate the high level of precision necessary for transferring virtual plans into the operating room. We also present a complete computer-aided surgery (CAS) system developed in close collaboration with surgeons. Surgery planning and simulation include construction of 3D surface models from Cone-beam CT (CBCT), dynamic cephalometry, semi-automatic mirroring, interactive cutting of bone and bony segment repositioning. A virtual setup can be used to manufacture positioning splints for intra-operative guidance. The system provides further intra-operative assistance with the help of a computer display showing jaw positions and 3D positioning guides updated in real-time during the surgical procedure. The CAS system aids in dealing with complex cases with benefits for the patient, with surgical practice, and for orthodontic finishing. Advanced software tools for diagnosis and treatment planning allow preparation of detailed operative plans, osteotomy repositioning, bone reconstructions, surgical resident training and assessing the difficulties of the surgical procedures prior to the surgery. CAS has the potential to make the elaboration of the surgical plan a more flexible process, increase the level of detail and accuracy of the plan, yield higher operative precision and control, and enhance documentation of cases. Supported by NIDCR DE017727, and DE018962 PMID:20816308

Cevidanes, Lucia; Tucker, Scott; Styner, Martin; Kim, Hyungmin; Chapuis, Jonas; Reyes, Mauricio; Proffit, William; Turvey, Timothy; Jaskolka, Michael

2009-01-01

269

Modeling of Mantle Convection in 3D Subduction Zones  

Microsoft Academic Search

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

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

2010-01-01

270

Particle trajectories and acceleration during 3D fan reconnection  

Microsoft Academic Search

Context: The primary energy release in solar flares is almost certainly due to magnetic reconnection, making this a strong candidate as a mechanism for particle acceleration. While particle acceleration in 2D geometries has been widely studied, investigations in 3D are a recent development. Two main classes of reconnection regimes at a 3D magnetic null point have been identified: fan and

S. Dalla; P. K. Browning

2008-01-01

271

3D MURALE: a multimedia system for archaeology  

Microsoft Academic Search

This paper introduces the 3D Measurement and Virtual Reconstruction of Ancient Lost Worlds of Europe system (3D MURALE). It consists of a set of tools for recording, reconstructing, encoding, visualising and database searching\\/querying that operate on buildings, building parts, statues, statue parts, pottery, stratigraphy, terrain geometry and texture and material texture. The tools are loosely linked together by a common

John Cosmas; Take Itegaki; Damian Green; Edward Grabczewski; Fred Weimer; Luc J. Van Gool; Alexey Zalesny; Desi Vanrintel; Franz Leberl; Markus Grabner; Konrad Schindler; Konrad F. Karner; Michael Gervautz; Stefan Hynst; Marc Waelkens; Marc Pollefeys; Roland DeGeest; Robert Sablatnig; Martin Kampel

2001-01-01

272

Methods for comparing 3D surface attributes  

NASA Astrophysics Data System (ADS)

A common task in data analysis is to compare two or more sets of data, statistics, presentations, etc. A predominant method in use is side-by-side visual comparison of images. While straightforward, it burdens the user with the task of discerning the differences between the two images. The user if further taxed when the images are of 3D scenes. This paper presents several methods for analyzing the extent, magnitude, and manner in which surfaces in 3D differ in their attributes. The surface geometry are assumed to be identical and only the surface attributes (color, texture, etc.) are variable. As a case in point, we examine the differences obtained when a 3D scene is rendered progressively using radiosity with different form factor calculation methods. The comparison methods include extensions of simple methods such as mapping difference information to color or transparency, and more recent methods including the use of surface texture, perturbation, and adaptive placements of error glyphs.

Pang, Alex; Freeman, Adam

1996-03-01

273

PIXIE3D: A Parallel, Implicit, eXtended MHD 3D Code  

NASA Astrophysics Data System (ADS)

We report on the development of PIXIE3D, a 3D parallel, fully implicit Newton-Krylov extended MHD code in general curvilinear geometry. PIXIE3D employs a second-order, finite-volume-based spatial discretization that satisfies remarkable properties such as being conservative, solenoidal in the magnetic field to machine precision, non-dissipative, and linearly and nonlinearly stable in the absence of physical dissipation. PIXIE3D employs fully-implicit Newton-Krylov methods for the time advance. Currently, second-order implicit schemes such as Crank-Nicolson and BDF2 (2^nd order backward differentiation formula) are available. PIXIE3D is fully parallel (employs PETSc for parallelism), and exhibits excellent parallel scalability. A parallel, scalable, MG preconditioning strategy, based on physics-based preconditioning ideas, has been developed for resistive MHD, and is currently being extended to Hall MHD. In this poster, we will report on progress in the algorithmic formulation for extended MHD, as well as the the serial and parallel performance of PIXIE3D in a variety of problems and geometries. L. Chac'on, Comput. Phys. Comm., 163 (3), 143-171 (2004) L. Chac'on et al., J. Comput. Phys. 178 (1), 15- 36 (2002); J. Comput. Phys., 188 (2), 573-592 (2003) L. Chac'on, 32nd EPS Conf. Plasma Physics, Tarragona, Spain, 2005 L. Chac'on et al., 33rd EPS Conf. Plasma Physics, Rome, Italy, 2006

Chacon, Luis

2006-10-01

274

3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

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

Zhu, Zhigang

275

3D Computer Vision and Video Computing 3D Vision3D Vision  

E-print Network

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

Zhu, Zhigang

276

X3D-edit authoring for extensible 3D (X3D) graphics  

Microsoft Academic Search

A primary benefit of the Extensible 3D (X3D) Graphics Specification is the use of the Extensible Markup Language (XML) to encode 3D scenes compatibly with the next-generation Web. XML-based languages provide a wide variety of new capabilities for authoring, processing and validating graphics scenes. X3D-Edit is an authoring tool for X3D scenes developed using IBM's Xeena, an XML-based tool-building application.

Donald P. Brutzman

2003-01-01

277

Entourage3D  

NSDL National Science Digital Library

From charettes to ateliers, architectural education is dedicated to collaborative learning environments. In recent years, some of these activities have migrated to the web, and along the way a number of forward-thinking individuals have seen fit to create online resources that might be of use to students working in this field. Created by the Design Machine Group at the University of Washington's Department of Architecture, the entourage 3D database includes "building blocks, complete models, and finishing touches for users to download and use." Visitors will appreciate the fact that they can browse these resources by such categories as building component, lighting element, office furniture, or street furniture. Visitors will need to complete a free registration before looking at the various designs and plans available here, but this only takes a few moments.

278

GPR measurements to assess the Emeelt active fault's characteristics in a highly smooth topographic context, Mongolia  

NASA Astrophysics Data System (ADS)

To estimate the seismic hazard, the geometry (dip, length and orientation) and the dynamics (type of displacements and amplitude) of the faults in the area of interest need to be understood. In this paper, in addition to geomorphologic observations, we present the results of two ground penetrating radar (GPR) campaigns conducted in 2010 and 2011 along the Emeelt fault in the vicinity of Ulaanbaatar, capital of Mongolia, located in an intracontinental region with low deformation rate that induces long recurrence time between large earthquakes. As the geomorphology induced by the fault activity has been highly smoothed by erosion processes since the last event, the fault location and geometry is difficult to determine precisely. However, by using GPR first, a non-destructive and fast investigation, the fault and the sedimentary deposits near the surface can be characterized and the results can be used for the choice of trench location. GPR was performed with a 50 MHz antenna over 2-D lines and with a 500 MHz antenna for pseudo-3-D surveys. The 500 MHz GPR profiles show a good consistency with the trench observations, dug next to the pseudo-3-D surveys. The 3-D 500 MHz GPR imaging of a palaeochannel crossed by the fault allowed us to estimate its lateral displacement to be about 2 m. This is consistent with a right lateral strike-slip displacement induced by an earthquake around magnitude 7 or several around magnitude 6. The 2-D 50 MHz profiles, recorded perpendicular to the fault, show a strong reflection dipping to the NE, which corresponds to the fault plane. Those profiles provided complementary information on the fault such as its location at shallow depth, its dip angle (from 23° to 35°) and define its lateral extension.

Dujardin, Jean-Rémi; Bano, Maksim; Schlupp, Antoine; Ferry, Matthieu; Munkhuu, Ulziibat; Tsend-Ayush, Nyambayar; Enkhee, Bayarsaikhan

2014-07-01

279

3D Model of the Tuscarora Geothermal Area  

SciTech Connect

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.

James E. Faulds

2013-12-31

280

3D Model of the Tuscarora Geothermal Area  

DOE Data Explorer

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.

James E. Faulds

281

Exploring in 3D: Make your own 3D glasses  

NSDL National Science Digital Library

In this lesson, learners will construct their own 3-D glasses in order to use them on 3-D images, such as images of the Sun from the STEREO spacecraft. This activity requires special materials, such as red and blue acetate paper and can be used with an accompanying activity, titled Create Your Own 3-D Images.

282

Surface roughness of ancient seismic faults exhumed from 10 km depths (Gole Larghe Fault, Italian Alps) characterized over five orders of magnitude  

NASA Astrophysics Data System (ADS)

Fault surface roughness is a principal factor influencing earthquake mechanics, and particularly rupture initiation, propagation, and arrest, however little data currently exists on fault surfaces at seismogenic depths. Here we investigate the roughness of slip surfaces from the seismogenic strike-slip Gole Larghe Fault Zone, exhumed from ca. 10 km depth. The fault exploited pre-existing joints and is hosted in granitoid rocks of the Adamello batholith (Italian Alps). Individual seismogenic slip surfaces generally show a first phase of cataclasite production, and a second phase with beautifully preserved pseudotachylytes of variable thickness. We determined the geometry of fault traces over five orders of magnitude using terrestrial laser-scanning (LIDAR, ca. 500 m to 1 m scale), and 3D mosaics of high-resolution rectified digital photographs (10 m to <1 mm scale). LIDAR scans and photomosaics were georeferenced in 3D using a Differential Global Positioning System, allowing detailed multiscale reconstruction of fault traces. The combination of LIDAR and high-resolution photos used in this study has the advantage, over classical LIDAR-only surveys, that the spatial resolution of rectified photographs can be very high (0.2 mm/pixel in this study), allowing for detailed outcrop characterization. Fourier power spectrum analysis of the fault profiles revealed a self-affine behaviour over 3 to 5 orders of magnitude, with Hurst exponents ranging between 0.6 and 0.8. Roughness anisotropy is always small to negligible for the Gole Larghe Fault Zone, while roughness of pre-existing joints is not significantly different from the seismogenic fault surfaces. These observations are consistent with the generally small offsets shown by individual seismogenic fault surfaces, and indicate that precursor joints have a strong influence on the roughness of the fault surfaces. From a methodological point of view, the technique used here is advantageous over direct measurements of exposed fault surfaces in that it preserves, in cross-section, all of the structures which contribute to fault roughness, and removes any subjectivity introduced by the need to distinguish roughness of original slip surfaces from roughness induced by secondary weathering processes. Moreover, offsets can be measured by means of suitable markers and fault rocks are preserved, hence their thickness, composition and structural features can be characterised, providing an integrated dataset which sheds new light on mechanisms of roughness evolution with slip and concomitant fault rock production. Parameters from the Fourier analysis have been used to reconstruct synthetic 3D fault surfaces with an equivalent roughness by means of 2D Fourier synthesis, which can be in turn be used as input data for different fault numerical models.

Bistacchi, A.; Griffith, W. A.; Nielsen, S. B.; Smith, S. A.; di Toro, G.; Jones, R. R.

2010-12-01

283

Reconstruction of 3D Human Facial Images Using Partial Differential Equations  

Microsoft Academic Search

One of the challenging problems in geometric modeling and computer graphics is the construction of realistic human facial geometry. Such geometry are essential for a wide range of applications, such as 3D face recognition, virtual reality applications, facial expression simulation and computer based plastic surgery application. This paper addresses a method for the construction of 3D geometry of human faces

Eyad Elyan; Hassan Ugail

2007-01-01

284

Imaging Fault Structure of the 1995 Kozani-Grevena Earthquake Sequence, Greece Using High Precision Aftershock Locations.  

NASA Astrophysics Data System (ADS)

The May 13, 1995 Kozani-Grevena earthquake (Mw=6.5) is a natural laboratory for studying crustal normal fault systems. The event and its aftershocks have been well observed geodetically, seismically, and geologically, providing an opportunity to integrate data sets to create a detailed subsurface fault model and investigate triggering and deformation associated with a large normal fault earthquake. Previous modeling of the earthquake has focused primarily on single geodetic data sets (e.g. inSAR - Meyer et al, 1996, GPS - Clarke et al., 1997) and has led to conflicting subsurface fault interpretations. In order to better model the subsurface fault geometry we have relocated aftershocks and use the interpretation of multiple complementary data sets to constrain a 3D boundary-element model of the earthquake sequence. Using the Double-Difference earthquake location algorithm (Ellsworth and Wauldhauser, 2000) we have reduced the hypocentral location error by a factor of ~10, obtaining high-precision aftershock locations for 650 events recorded by a local network (Hatzfeld et al., 1997). Relocated aftershocks cluster into a system of planar structures that reveal the "fine" structure of faults that were active during the earthquake sequence. The master normal fault dips 45° north from 6-14 km depth and extends over a length of ~12 km, consistent with the Harvard CMT solution. Two south-dipping antithetic faults extend from the western half of the master fault, one located at the up-dip tip extending from 4-6 km depth, and the second located at approximately the mid-point of the master fault in cross section from 6-9 km depth. These antithetic faults dip 45° and 35° respectively. At the western end of the rupture is a system of strike-slip faults in an orientation consistent with slip-transfer or segment linking structures. Fault patterns interpreted from the aftershock distribution form the basis of a 3D boundary element model using Poly3D. This code uses a mesh of contiguous triangular dislocation elements to capture the essential features of complex fault geometry in an idealized elastic half space. The mechanical model allows us to test the consistency of fault interpretations based on aftershock locations against surface geodetic and geologic data as well as to understand the mechanics of triggering and strain accommodation associated with the earthquake sequence. An improved fault model for the Kozani-Grevena earthquake is important for assessing seismic hazard and for understanding the mechanics of normal fault earthquakes and normal fault systems.

Resor, P. G.; Beroza, G. C.; Pollard, D. D.

2001-12-01

285

Northward Channel flow in Northern Tibet revealed1 from 3D magnetotelluric modelling2  

E-print Network

Northward Channel flow in Northern Tibet revealed1 from 3D magnetotelluric modelling2 3 Wenbo Weia at mid-crustal depths in northern Tibet. The 3D MT inversion25 results, supported by synthetic modelling fault at mid-to-lower crustal31 depths.32 #12;2 Keywords: magnetotellurics, Tibet, 3D modelling, channel

Jones, Alan G.

286

Architect Studio 3D  

NSDL National Science Digital Library

When one thinks of the vast number of influential architects the world has seen during the past centuries, one is reminded of Dies van der Rohe, Walter Gropius, Le Corbusier, and of course, that Master from the Midwest, Frank Lloyd Wright. It's hard to imagine that a website would be able to conjure up the spirit of this famous and controversial architect, but it does just that. With the assistance of a user-friendly interface, the Architect Studio 3D site allows users to build a model home for a number of clients and their very specific needs. With a small icon of the master residing in the bottom of the left-hand corner of the screen, visitors will get the chance to create their own building for one of these clients, and then submit it to a design gallery for consideration by others. For those visitors who may be less familiar with the world of architecture, there is a handy section titled "About Architecture". Here they will find a glossary of terms that provide brief descriptions of such important concepts and design elements as site, wall, client, roof, and exterior material. Of course, no such site would be complete without a brief biography of the man himself, and as such, a nice overview of his work and life is provided here as well.

287

Modeling of Mantle Convection in 3D Subduction Zones  

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

288

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

289

3D Op&cs Crayola 3D chalk, 3D markers  

E-print Network

chromadepth.com #12;from chromadepth.com #12;from chromadepth.com #12;from Disney Viewmaster 3Dguy.tv, ormaqstudios.com Red/blue 3D glasses Wikimedia, Avatar 3D movies do 3D movies do it? · Using polarized light Polarizing filter Light waves

Anderson, Betty Lise

290

ALE3D Rolling Simulations  

SciTech Connect

Hot rolling is a problem involving large deformations during the process of turning an ingot into a thin sheet. As a result of the large deformations inherent in the process, significant amounts of energy are put into the ingot mechanically, most of which results in heat generation. Therefore, in order to predict the results of rolling both the mechanical and the thermal factors must accurately represent the real conditions. The factors which must be properly tuned include interface friction, mass scaling to decrease computation times, heat transfer at the interface, convective heat transfer from the ingot, and convective heat transfer from the roll. Since these parameters are generally not measurable the correct values must be derived by tuning the parameters so that solutions match some other measurable result. The interface friction will be tuned using an ALE3D input deck which has been set up to output the torque applied to the roll during the pass. The friction coefficient will be adjusted so that the computed torque matches the measured value. The various heat transfer coefficients are dependent on each other, and are tuned based on measured roll surface temperatures, ingot exit temperatures, and the energy input through the mechanical deformation of the ingot. The heat transfer coefficient at the interface has been found to be approximately 1.25 x 10{sup 5} W/m{sup 2}K, based on estimates of how much heat can be taken from the roll surface by coolant and matching a roll surface temperature. The convection coefficient on the ingot surface has been assumed to be 100 W/m{sup 2}K, on the high end for convection to air. However, this convection coefficient is low enough that the ingot should cool uniformly through its thickness as it would with a lower convection coefficient. Also necessary in accurate modeling is a good description of material behavior. In order to aid the development of an accurate material model an ALE3D input deck which simulates compression tests with temperature gradients has been developed. The model output engineering stress-strain curves which can be compared to the experimentally collected data. Also, comparisons of the deformed shapes can be made. The model has been tuned using MTS parameters for AA 5182 and will be ready for use when parameters for AA 2024 are experimentally developed. Currently, more work is needed to properly tune all the model parameters. A parameterized three dimensional geometry and mesh has been created so that once the parameters are tuned the transition to three dimensional simulations should be quick.

Riordan, T

2006-07-27

291

Influence of faults on groundwater flow and transport at YuccaMountain, Nevada  

SciTech Connect

Numerical simulations of groundwater flow at Yucca Mountain, Nevada are used to investigate how faults influence groundwater flow pathways and regional-scale macrodispersion. The 3-D model has a unique grid block discretization that facilitates the accurate representation of the complex geologic structure present in faulted formations. Each hydrogeologic layer is discretized into a single layer of irregular and dipping grid blocks, and faults are discretized such that they are laterally continuous and varied in displacement varies along strike. In addition, the presence of altered fault zones is explicitly modeled, as appropriate. Simulations show that upward head gradients can be readily explained by the geometry of hydrogeologic layers, the variability of layer permeabilities, and the presence of permeable fault zones or faults with displacement only, not necessarily by upwelling from a deep aquifer. Large-scale macrodispersion results from the vertical and lateral diversion of flow near the contact of high- and low-permeability layers at faults, and from upward flow within high-permeability fault zones. Conversely, large-scale channeling can occur as a result of groundwater flow into areas with minimal fault displacement. Contaminants originating at the water table can flow in a direction significantly different from that of the water table gradient, and isolated zones of contaminants can occur at the water table downgradient. By conducting both 2-D and 3-D simulations, we show that the 2-D cross-sectional models traditionally used to examine flow in faulted formations may not be appropriate. In addition, the influence of a particular type of fault cannot be generalized; depending on the location where contaminants enter the saturated zone, faults may either enhance or inhibit vertical dispersion.

Cohen, Andrew J.B.; Sitar, Nicholas

1999-10-07

292

3D Hall MHD Simulation Studies (NRLHALL3D)  

Microsoft Academic Search

A 3D Hall MHD simulation code (NRLHALL3D) has recently been developed at the Naval Research Laboratory. The 3D Hall MHD equations are solved in conservative form using a finite-volume scheme. The hydrodynamic variables in a cell are updated by calculating fluxes across the cell interfaces. The fluxes of mass, momentum, and energy across cell interfaces are calculated by integrating a

J. D. Huba

2001-01-01

293

Inuit3D: An Interactive Virtual 3D Web Exhibition  

Microsoft Academic Search

The Canadian Museum of Civilization and the National Research Council ofCanada collaborated on the production of Inuit 3D, one of six inaugural VirtualMuseum of Canada exhibitions launched in April 2001. Inuit 3D is an interactiveexhibition in which visitors navigate through three exhibition halls andinteractively examine twelve 3D models of objects from the Museum's collection.Introductory videos are presented at the entrance

Frank Corcoran; Jeffrey Demaine; Michel Picard; Louis-Guy Dicaire; John Taylor

2002-01-01

294

Analysis of 3d Magnetotelluric Measurements Over the Coso Geothermal Field  

NASA Astrophysics Data System (ADS)

We have carried out an investigation of the Coso Geothermal field utilizing a dense grid of magnetotelluric (MT) stations plus a single line of contiguous bipole array profiling over the east flank of the field. Motivation for this study is that electrical resistivity/conductivity mapping can contribute to better understanding of enhanced geothermal systems (EGS) by imaging the geometry, bounds and controlling structures in existing production, and by monitoring changes in the underground resistivity properties in the vicinity of injection due to fracture porosity enhancement. Initial analysis of the Coso MT data was carried out using 2D MT imaging technology to construct a starting 3D resistivity model from a series of 2D resistivity images obtained using the inline electric field measurements (Zxy impedance elements) along different measurement transects. This model was then refined through a 3D inversion process. The 3D resisitivity model clearly showed the controlling geological structures influencing well production at Coso and shows correlations with mapped surface features such as faults and regional geoelectric strike. We have also correlated the model with an acoustic and shear velocity model of the field to show that the near-vertical high conductivity (low resistivity) structure on the eastern flank of the producing field is also a zone of increase acoustic velocity and increased Vp/Vs ratio.

Newman, G. A.; Gasperikova, E.; Hoversten, M.

2007-12-01

295

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

SciTech Connect

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

Jamieson, G.A.

1996-12-31

296

Evolution of Archaea in 3D modeling  

NASA Astrophysics Data System (ADS)

The analysis of all groups of Archaea performed in two-dimensions have demonstrated a specific distribution of Archaean species as a function of pH/temperature, temperature/salinity and pH/salinity. Work presented here is an extension of this analysis with a three dimensional (3D) modeling in logarithmic scale. As it was shown in 2D representation, the "Rules of the Diagonal" have been expressed even more clearly in 3D modeling. In this article, we used a 3D Mesh modeling to show the range of distribution of each separate group of Archaea as a function of pH, temperature, and salinity. Visible overlap and links between different groups indicate a direction of evolution in Archaea. The major direction in ancestral life (vector of evolution) has been indicated: from high temperature, acidic, and low-salinity system towards low temperature, alkaline and high salinity systems. Specifics of the geometrical coordinates and distribution of separate groups of Archaea in 3 D scale were analyzed with a mathematical description of the functions. Based on the obtained data, a new model for the origin and evolution of life on Earth is proposed. The geometry of this model is described by a hyperboloid of one sheet. Conclusions of this research are consistent with previous results derived from the two-dimensional diagrams. This approach is suggested as a new method for analyzing any biological group in accordance to its environmental parameters.

Pikuta, Elena V.; Tankosic, Dragana; Sheldon, Rob

2012-11-01

297

3D Spectroscopy in Astronomy  

NASA Astrophysics Data System (ADS)

Preface; Acknowledgements; 1. Introductory review and technical approaches Martin M. Roth; 2. Observational procedures and data reduction James E. H. Turner; 3. 3D Spectroscopy instrumentation M. A. Bershady; 4. Analysis of 3D data Pierre Ferruit; 5. Science motivation for IFS and galactic studies F. Eisenhauer; 6. Extragalactic studies and future IFS science Luis Colina; 7. Tutorials: how to handle 3D spectroscopy data Sebastian F. Sánchez, Begona García-Lorenzo and Arlette Pécontal-Rousset.

Mediavilla, Evencio; Arribas, Santiago; Roth, Martin; Cepa-Nogué, Jordi; Sánchez, Francisco

2011-09-01

298

Spherical 3D isotropic wavelets  

NASA Astrophysics Data System (ADS)

Context. Future cosmological surveys will provide 3D large scale structure maps with large sky coverage, for which a 3D spherical Fourier-Bessel (SFB) analysis in spherical coordinates is natural. Wavelets are particularly well-suited to the analysis and denoising of cosmological data, but a spherical 3D isotropic wavelet transform does not currently exist to analyse spherical 3D data. Aims: The aim of this paper is to present a new formalism for a spherical 3D isotropic wavelet, i.e. one based on the SFB decomposition of a 3D field and accompany the formalism with a public code to perform wavelet transforms. Methods: We describe a new 3D isotropic spherical wavelet decomposition based on the undecimated wavelet transform (UWT) described in Starck et al. (2006). We also present a new fast discrete spherical Fourier-Bessel transform (DSFBT) based on both a discrete Bessel transform and the HEALPIX angular pixelisation scheme. We test the 3D wavelet transform and as a toy-application, apply a denoising algorithm in wavelet space to the Virgo large box cosmological simulations and find we can successfully remove noise without much loss to the large scale structure. Results: We have described a new spherical 3D isotropic wavelet transform, ideally suited to analyse and denoise future 3D spherical cosmological surveys, which uses a novel DSFBT. We illustrate its potential use for denoising using a toy model. All the algorithms presented in this paper are available for download as a public code called MRS3D at http://jstarck.free.fr/mrs3d.html

Lanusse, F.; Rassat, A.; Starck, J.-L.

2012-04-01

299

Adaptive 3D Web Sites  

Microsoft Academic Search

In recent years, technological developments have made it possible to build interactive 3D models of objects and 3D Virtual Environments that can be experienced through the Web, using common, low-cost personal computers. As in the case of Web-based hypermedia, adaptivity can play an important role in increasing the usefulness, effectiveness and usability of 3D Web sites, i.e., Web sites distributing

Luca Chittaro; Roberto Ranon

2007-01-01

300

Static 3D image space  

Microsoft Academic Search

As three-dimensional (3D) techniques continue to evolve from their humble beginnings-nineteenth century stereo photographs and twentieth century movies and holographs, the urgency for advancement in 3D display is escalating, as the need for widespread application in medical imaging, baggage scanning, gaming, television and movie display, and military strategizing increases. The most recent 3D developments center upon volumetric display, which generate

Badia Koudsi; Jim J. Sluss Jr.

2010-01-01

301

Multiaperture telecentric lens for 3D reconstruction.  

PubMed

We present a telecentric lens that is able to gain 3D information. The proposed lens system has multiple aperture stops, which enable it to capture multidirectional parallel light rays, while a conventional telecentric lens has only one aperture stop and can capture only light rays that are perpendicular to the lens. We explain the geometry of the multiaperture telecentric system and show that correspondences fall on a line like those in a conventional stereo. As it is a single-lens sensor, we also introduce the principles of 3D reconstruction. Unlike a conventional stereo camera, the disparity of a scene point measured by the proposed lens system is linearly proportional to the depth of a scene point. PMID:21478979

Kim, Jun-Sik; Kanade, Takeo

2011-04-01

302

Multimillion Atom Simulations with NEMO 3-D  

E-print Network

The rapid progress in nanofabrication technologies has led to the emergence of new classes of nanodevices and structures. At the atomic scale of novel nanostructured semiconductors the distinction between new device and new material is blurred and device physics and material science meet. The quantum mechanical effects in the electronic states of the device and the granular, atomistic representation of the underlying material become important. The variety of geometries, materials, and doping configurations in semiconductor devices at the nanoscale suggests that a general nanoelectronic modeling tool is needed. The Nanoelectronic Modeling tool (NEMO 3-D) has been developed to address these needs. Based on the atomistic valence-force field (VFF) method and a variety of nearest-neighbor tight-binding models, NEMO 3-D enables the computation of strain for over 64 million atoms and of electronic structure for over 52 million atoms, corresponding to volumes of (110nmx110nmx110nm) and (101nmx101nmx101nm), respective...

Ahmed, Shaikh; Rahman, Rajib; Usman, Muhammad; Lee, Sunhee; Ryu, Hoon; Bae, Hansang; Clark, Steve; Haley, Benjamin; Naumov, Maxim; Saied, Faisal; Korkusinski, Marek; Kennel, Rick; McLennan, Michael; Boykin, Timothy B; Klimeck, Gerhard

2009-01-01

303

3D gaze tracking system for NVidia 3D Vision®.  

PubMed

Inappropriate parallax setting in stereoscopic content generally causes visual fatigue and visual discomfort. To optimize three dimensional (3D) effects in stereoscopic content by taking into account health issue, understanding how user gazes at 3D direction in virtual space is currently an important research topic. In this paper, we report the study of developing a novel 3D gaze tracking system for Nvidia 3D Vision(®) to be used in desktop stereoscopic display. We suggest an optimized geometric method to accurately measure the position of virtual 3D object. Our experimental result shows that the proposed system achieved better accuracy compared to conventional geometric method by average errors 0.83 cm, 0.87 cm, and 1.06 cm in X, Y, and Z dimensions, respectively. PMID:24110407

Wibirama, Sunu; Hamamoto, Kazuhiko

2013-01-01

304

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

305

Immersive 3D geovisualisation in higher education  

NASA Astrophysics Data System (ADS)

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.

Philips, Andrea; Walz, Ariane; Bergner, Andreas; Graeff, Thomas; Heistermann, Maik; Kienzler, Sarah; Korup, Oliver; Lipp, Torsten; Schwanghart, Wolfgang; Zeilinger, Gerold

2014-05-01

306

Anisotropy effects on 3D waveform inversion  

NASA Astrophysics Data System (ADS)

In the recent years 3D waveform inversion has become achievable procedure for seismic data processing. A number of datasets has been inverted and presented (Warner el al 2008, Ben Hadj at all, Sirgue et all 2010) using isotropic 3D waveform inversion. However the question arises will the results be affected by isotropic assumption. Full-wavefield inversion techniques seek to match field data, wiggle-for-wiggle, to synthetic data generated by a high-resolution model of the sub-surface. In this endeavour, correctly matching the travel times of the principal arrivals is a necessary minimal requirement. In many, perhaps most, long-offset and wide-azimuth datasets, it is necessary to introduce some form of p-wave velocity anisotropy to match the travel times successfully. If this anisotropy is not also incorporated into the wavefield inversion, then results from the inversion will necessarily be compromised. We have incorporated anisotropy into our 3D wavefield tomography codes, characterised as spatially varying transverse isotropy with a tilted axis of symmetry - TTI anisotropy. This enhancement approximately doubles both the run time and the memory requirements of the code. We show that neglect of anisotropy can lead to significant artefacts in the recovered velocity models. We will present inversion results of inverting anisotropic 3D dataset by assuming isotropic earth and compare them with anisotropic inversion result. As a test case Marmousi model extended to 3D with no velocity variation in third direction and with added spatially varying anisotropy is used. Acquisition geometry is assumed as OBC with sources and receivers everywhere at the surface. We attempted inversion using both 2D and full 3D acquisition for this dataset. Results show that if no anisotropy is taken into account although image looks plausible most features are miss positioned in depth and space, even for relatively low anisotropy, which leads to incorrect result. This may lead to misinterpretation of results. However if correct physics is used results agree with correct model. Our algorithm is relatively affordable and runs on standard pc clusters in acceptable time. Refferences: H. Ben Hadj Ali, S. Operto and J. Virieux. Velocity model building by 3D frequency-domain full-waveform inversion of wide-aperture seismic data, Geophysics (Special issue: Velocity Model Building), 73(6), P. VE101-VE117 (2008). L. Sirgue, O.I. Barkved, J. Dellinger, J. Etgen, U. Albertin, J.H. Kommedal, Full waveform inversion: the next leap forward in imaging at Valhall, First Brake April 2010 - Issue 4 - Volume 28 M. Warner, I. Stekl, A. Umpleby, Efficient and Effective 3D Wavefield Tomography, 70th EAGE Conference & Exhibition (2008)

Stekl, I.; Warner, M.; Umpleby, A.

2010-12-01

307

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

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.

Langenheim, V. E.; Powell, R. E.

2009-01-01

308

Fault slip distribution and fault roughness  

NASA Astrophysics Data System (ADS)

We present analysis of the spatial correlations of seismological slip maps and fault topography roughness, illuminating their identical self-affine exponent. Though the complexity of the coseismic spatial slip distribution can be intuitively associated with geometrical or stress heterogeneities along the fault surface, this has never been demonstrated. Based on new measurements of fault surface topography and on statistical analyses of kinematic inversions of slip maps, we propose a model, which quantitatively characterizes the link between slip distribution and fault surface roughness. Our approach can be divided into two complementary steps: (i) Using a numerical computation, we estimate the influence of fault roughness on the frictional strength (pre-stress). We model a fault as a rough interface where elastic asperities are squeezed. The Hurst exponent ?, characterizing the self-affinity of the frictional strength field, approaches ?, where ? is the roughness exponent of the fault surface in the direction of slip. (ii) Using a quasi-static model of fault propagation, which includes the effect of long-range elastic interactions and spatial correlations in the frictional strength, the spatial slip correlation is observed to scale as ?, where ? represents the Hurst exponent of the slip distribution. Under the assumption that the origin of the spatial fluctuations in frictional strength along faults is the elastic squeeze of fault asperities, we show that self-affine geometrical properties of fault surface roughness control slip correlations and that ?. Given that ? for a wide range of faults (various accumulated displacement, host rock and slip movement), we predict that ?. Even if our quasi-static fault model is more relevant for creeping faults, the spatial slip correlations observed are consistent with those of seismological slip maps. A consequence is that the self-affinity property of slip roughness may be explained by fault geometry without considering dynamical effects produced during an earthquake.

Candela, Thibault; Renard, François; Schmittbuhl, Jean; Bouchon, Michel; Brodsky, Emily E.

2011-11-01

309

GRAPHICS PROGRAMMING SECTION D -JAVA 3D  

E-print Network

GRAPHICS PROGRAMMING SECTION D - JAVA 3D 1SECTION D - GRAPHICS 3-D........................................................................................ 78 ©Gary Hill September 2004 Java 3-D 1 of 13 #12;GRAPHICS PROGRAMMING SECTION D - GRAPHICS 3-D 30 Graphics 3D: Introduction to Java 3D Java 3D is a high level, scene graph based Application Programming

Hill, Gary

310

3D Game Programming Introduction  

E-print Network

Graphics Advance Computer Graphics Game Design Visual Effect Computer Animation Programming C/C++ Human type of object location of vertex end of object definition GAMEGAME What is video game?What is video2012/9/18 1 3D Game Programming Introduction 3D Game Programming Introduction Ming-Te Chi

Ouhyoung, Ming

311

JavaSound3D  

NSDL National Science Digital Library

This java application allows the user to look at the waveform of WAV files or microphone inputs in detail. One can see a graph of the fast fourier transform (FFT) of the data in the window in a 2D or 3D graph. The 3D graph shows how the FFT changes over time.

Bliss, Jennifer; Steele, Brad; Mechtly, Bruce

2008-07-29

312

3D World Building System  

ScienceCinema

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.

None

2014-02-26

313

Market study: 3-D eyetracker  

NASA Technical Reports Server (NTRS)

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.

1977-01-01

314

Diffusion Geometry Diffusion Geometry  

E-print Network

Diffusion Geometry Diffusion Geometry for High Dimensional Data Matthew J. Hirn July 3, 2013 #12;Diffusion Geometry Introduction Embedding of closed curve Figure: Left: A closed, non-self-intersecting curve in 3 dimensions. Right: Its embedding as a circle. #12;Diffusion Geometry Introduction Cartoon

Hirn, Matthew

315

Euro3D Science Conference  

NASA Astrophysics Data System (ADS)

The Euro3D RTN is an EU funded Research Training Network to foster the exploitation of 3D spectroscopy in Europe. 3D spectroscopy is a general term for spectroscopy of an area of the sky and derives its name from its two spatial + one spectral dimensions. There are an increasing number of instruments which use integral field devices to achieve spectroscopy of an area of the sky, either using lens arrays, optical fibres or image slicers, to pack spectra of multiple pixels on the sky (``spaxels'') onto a 2D detector. On account of the large volume of data and the special methods required to reduce and analyse 3D data, there are only a few centres of expertise and these are mostly involved with instrument developments. There is a perceived lack of expertise in 3D spectroscopy spread though the astronomical community and its use in the armoury of the observational astronomer is viewed as being highly specialised. For precisely this reason the Euro3D RTN was proposed to train young researchers in this area and develop user tools to widen the experience with this particular type of data in Europe. The Euro3D RTN is coordinated by Martin M. Roth (Astrophysikalisches Institut Potsdam) and has been running since July 2002. The first Euro3D science conference was held in Cambridge, UK from 22 to 23 May 2003. The main emphasis of the conference was, in keeping with the RTN, to expose the work of the young post-docs who are funded by the RTN. In addition the team members from the eleven European institutes involved in Euro3D also presented instrumental and observational developments. The conference was organized by Andy Bunker and held at the Institute of Astronomy. There were over thirty participants and 26 talks covered the whole range of application of 3D techniques. The science ranged from Galactic planetary nebulae and globular clusters to kinematics of nearby galaxies out to objects at high redshift. Several talks were devoted to reporting recent observations with newly completed 3D instruments - CIRPASS, GMOS, PMAS and SPIFFI. Work on 3D software, being developed as part of the Euro3D RTN, was also described and demonstrated. This proceedings volume, consisting of carefully refereed and edited manuscripts, represents the bulk of the talks at the conference and amply demonstrates that 3D spectroscopy is a lively and burgeoning field of optical observation.

Walsh, J. R.

2004-02-01

316

PLOT3D user's manual  

NASA Technical Reports Server (NTRS)

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.

Walatka, Pamela P.; Buning, Pieter G.; Pierce, Larry; Elson, Patricia A.

1990-01-01

317

3D vision system assessment  

NASA Astrophysics Data System (ADS)

In this paper, we report on the development of a 3D vision system consisting of a flat panel stereoscopic display and auto-converging stereo camera and an assessment of the system's use for robotic driving, manipulation, and surveillance operations. The 3D vision system was integrated onto a Talon Robot and Operator Control Unit (OCU) such that direct comparisons of the performance of a number of test subjects using 2D and 3D vision systems were possible. A number of representative scenarios were developed to determine which tasks benefited most from the added depth perception and to understand when the 3D vision system hindered understanding of the scene. Two tests were conducted at Fort Leonard Wood, MO with noncommissioned officers ranked Staff Sergeant and Sergeant First Class. The scenarios; the test planning, approach and protocols; the data analysis; and the resulting performance assessment of the 3D vision system are reported.

Pezzaniti, J. Larry; Edmondson, Richard; Vaden, Justin; Hyatt, Bryan; Chenault, David B.; Kingston, David; Geulen, Vanilynmae; Newell, Scott; Pettijohn, Brad

2009-02-01

318

Self collimation of ultrasound in a 3D sonic crystal  

E-print Network

We present the experimental demonstration of self-collimation (subdiffractive propagation) of an ultrasonic beam inside a three-dimensional sonic crystal. The crystal is formed by two crossed steel cylinders structures in a woodpile-like geometry disposed in water. Measurements of the 3D field distribution show that a narrow beam which diffractively spreads in the absence of the sonic crystal is strongly collimated in propagation inside the crystal, demonstrating the 3D self-collimation effect.

Soliveres, E; Perez-Arjona, I; Sanchez-Morcillo, V; Staliunas, K

2009-01-01

319

Nature of stress accommodation in sheared granular material: Insights from 3D numerical modeling  

NASA Astrophysics Data System (ADS)

Active faults often contain distinct accumulations of granular wear material. During shear, this granular material accommodates stress and strain in a heterogeneous manner that may influence fault stability. We present new work to visualize the nature of contact force distributions during 3D granular shear. Our 3D discrete numerical models consist of granular layers subjected to normal loading and direct shear, where gouge particles are simulated by individual spheres interacting at points of contact according to simple laws. During shear, we observe the transient microscopic processes and resulting macroscopic mechanical behavior that emerge from interactions of thousands of particles. We track particle translations and contact forces to determine the nature of internal stress accommodation with accumulated slip for different initial configurations. We view model outputs using novel 3D visualization techniques. Our results highlight the prevalence of transient directed contact force networks that preferentially transmit enhanced stresses across our granular layers. We demonstrate that particle size distribution (psd) controls the nature of the force networks. Models having a narrow (i.e. relatively uniform) psd exhibit discrete pipe-like force clusters with a dominant and focussed orientation oblique to but in the plane of shear. Wider psd models (e.g. power law size distributions D = 2.6) also show a directed contact force network oblique to shear but enjoy a wider range of orientations and show more out-of-plane linkages perpendicular to shear. Macroscopic friction level, is insensitive to these distinct force network morphologies, however, force network evolution appears to be linked to fluctuations in macroscopic friction. Our results are consistent with predictions, based on recent laboratory observations, that force network morphologies are sensitive to grain characteristics such as particle size distribution of a sheared granular layer. Our numerical approach offers the potential to investigate correlations between contact force geometry, evolution and resulting macroscopic friction, thus allowing us to explore ideas that heterogeneous force distributions in gouge material may exert an important control on fault stability and hence the seismic potential of active faults.

Mair, Karen; Hazzard, James F.

2007-07-01

320

3D temperature model of south-western South America  

NASA Astrophysics Data System (ADS)

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.

Tassara, Andres; Morales, Daniel

2013-04-01

321

Investigating Fault and Crust Strength With Thin-Shell Tectonic Modeling  

NASA Astrophysics Data System (ADS)

The behavior of many major faults on Earth can only be explained if they are assumed to be much weaker than predicted from Byerlee's Law: the frictional strength of major strike-slip faults like the San Andreas has been the subject of controversy for decades. The frictional strength of faults can be studied with numerical forward modeling. This requires knowledge of the 3-D geometry of the fault network, which is today available in places like California and Taiwan, where dense seismic networks have been in place for decades. We used a global finite-element code (shells) with a variable-resolution grid and global plate-driving forces to determine whether the effective friction on the San Andreas fault is high (0.6 - 1), intermediate (0.3 - 0.5) or low (? 0.2), whether a single value of effective friction can be used for all mapped active faults within California, and whether weakening of the ductile lower crust associated with faulting is important. We compared our model results to existing data on fault slip-rates, GPS velocities, stress field, and earthquakes depth distribution. The comparison indicates that all faults are weak (effective friction ? 0.2), and that additional weakening of the major faults in the network is important (i.e. brittle strength is variable among faults). The effective friction for the strongest faults in the region is in the range 0.2 - 0.05. The San Andreas fault is a very weak fault among weak faults, with effective friction < 0.05 for most of its length. All viable solutions also indicate that weakening of the lower crust below major faults in the system is necessary, i.e. major faults must exist as discrete, narrow shear zones in the lower crust as well, while minor faults could be limited to the brittle crust. We also applied this approach to the fault network surrounding Taiwan. The overall results here are not as robust as in California, due to the lack of unbiased heat flow data for the island, but they still indicate that faults must be equally weak and that major faults must extend at least into the lower crust.

Carena, S.; Moder, C.

2011-12-01

322

3D or not 3D - that is the question!  

Microsoft Academic Search

Should an introduction to 3D computer graphics and animation be a part of a general core curriculum requirement for all design majors regardless their concentration, track or degree?At ACM-SIGGRAPH it is taken for granted that a working knowledge of 3D computer graphics is a valuable if not necessary part of a versatile skill set to prepare design graduates for future

Gregory P. Garvey

2006-01-01

323

3D data model of transportation network in city  

NASA Astrophysics Data System (ADS)

Modern data-capture technology, especially digital photogrammetry technology, provides abundant data resources for digital city. Transportation network, forming framework of city, is an important component of city and a vital fundamental data of ITS and LBS (Location-based Services). Therefore, developing a data model is very valuable and significant which can describe 3D feature of city road network and support 3D navigation. Nowadays existing 3D GIS data models pay less attention to the support of transportation application, such as 3D vehicle navigation and traffic simulation, and previous GIS for transportation (GIS-T) data models failed to support 3D visualization. In view of it, we developed a 3D data model for transportation network that (1) supports of linear referencing system (LRS) and dynamic segmentation, (2) makes network topology build on the basis of 3D geometry network, and (3) realizes the transformation between linear coordinate and spatial coordinate. A performance study depicts that the proposed model can not only realize 3D visualization but also have transportation analysis (such 3D Vehicle navigation) more efficiently and conveniently.

Zuo, Xiao-qing; Li, Qing-quan; Yang, Bi-sheng

2005-10-01

324

Combining strong-motion, InSAR and GPS data to refine the fault geometry and source kinematics of the 2011, Mw 6.2, Christchurch earthquake (New Zealand)  

NASA Astrophysics Data System (ADS)

The space-time distribution of coseismic slip of the 2011 February 21, Mw 6.2, Christchurch earthquake, New Zealand, is explored, differently from all previous studies, through a joint inversion of geodetic and strong-motion data. The geodetic data consist of both global position system (GPS), from campaign and continuous stations, and synthetic aperture radar (SAR) interferograms from two ascending satellite tracks. The strong motion data consist of 10 stations located in the Canterbury plains, these stations offering a good azimuthal coverage of the event. The kinematic rupture model for the analysed event was obtained using the parametrization and non-linear inversion scheme proposed by Delouis et al. In particular, for any subfault we explore for the local source time function (local slip history), slip direction and rupture onset time. The geometry of the fault plane used for the kinematic inversion is inferred from the analysis of the geodetic data. To validate our results we perform a resolution study for both the single and complete data sets, and an errors analysis of our final kinematic rupture model. Considering the complexity highlighted by superficial deformation data, we adopted a fault model consisting of two partially overlapping segments, with dimensions 15 × 11 and 7 × 7 km2, corresponding to different faulting types. This two-fault model, instead of single-fault model, is needed to reconstruct the complex shape of the superficial deformation data. The total seismic moment resulting from the joint inversion is 3.0 × 1025 dyne · cm (Mw = 6.2) with an average rupture velocity of 2.0 km s-1.

Toraldo Serra, Eugenio Maria; Delouis, Bertrand; Emolo, Antonio; Zollo, Aldo

2013-09-01

325

Highway 3D model from image and lidar data  

NASA Astrophysics Data System (ADS)

We present a new method of highway 3-D model construction developed based on feature extraction in highway images and LIDAR data. We describe the processing road coordinate data that connect the image frames to the coordinates of the elevation data. Image processing methods are used to extract sky, road, and ground regions as well as significant objects (such as signs and building fronts) in the roadside for the 3D model. LIDAR data are interpolated and processed to extract the road lanes as well as other features such as trees, ditches, and elevated objects to form the 3D model. 3D geometry reasoning is used to match the image features to the 3D model. Results from successive frames are integrated to improve the final model.

Chen, Jinfeng; Chu, Henry; Sun, Xiaoduan

2014-05-01

326

S3D: An interactive surface grid generation tool  

NASA Technical Reports Server (NTRS)

S3D, an interactive software tool for surface grid generation, is described. S3D provides the means with which a geometry definition based either on a discretized curve set or a rectangular set can be quickly processed towards the generation of a surface grid for computational fluid dynamics (CFD) applications. This is made possible as a result of implementing commonly encountered surface gridding tasks in an environment with a highly efficient and user friendly graphical interface. Some of the more advanced features of S3D include surface-surface intersections, optimized surface domain decomposition and recomposition, and automated propagation of edge distributions to surrounding grids.

Luh, Raymond Ching-Chung; Pierce, Lawrence E.; Yip, David

1992-01-01

327

Geomorphological maps and 3d models in cave research  

NASA Astrophysics Data System (ADS)

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.

Ballesteros, Daniel; Jiménez-Sánchez, Montserrat; José Domínguez-Cuesta, María

2013-04-01

328

3D Motion recovery via affine Epipolar geometry  

Microsoft Academic Search

Algorithms to perform point-based motion estimation under orthographic and scaled orthographic projection abound in the literature. A key limitation of many existing algorithms is that they operate on the minimum amount of data required, often requiring the selection of a suitable minimal set from the available data to serve as a “local coordinate frame”. Such approaches are extremely sensitive to

Larry S. Shapiro; Andrew Zisserman; Michael Brady

1995-01-01

329

Geometry of Mixedmode Oscillations in the 3d Autocatalator  

E-print Network

­dimensional return map in a natural way. This bimodal map is capable of explaining the observed bifurcation sequence and periodic responses as a parameter is varied. See Fig. 2 for two typical bifurcation diagrams. The periodic 15 20 b b) 0 1 1 6 1 5 1 4 1 3 1 2 1 2 1 1 1 1 2 1 3 1 1 0 Figure 2: Bifurcation diagram for the 3­d

330

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

NASA Astrophysics Data System (ADS)

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.

Gabriel, Alice; Pelties, Christian

2014-05-01

331

3D Model of the San Emidio Geothermal Area  

DOE Data Explorer

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.

James E. Faulds

332

Map Rainfall in 3D  

NSDL National Science Digital Library

William Montgomery, New Jersey City University Summary This comprehensive activity introduces students to onscreen digitizing (OSD); automated mapping (Add XY Event Theme); table joins; 3D models; and automated ...

Montgomery, William

333

3-D Vector Field Simulation  

NSDL National Science Digital Library

This simulation illustrates a wide range of 3D vector fields, including spherical, radial, and linear. The fields can be displayed as vectors, particle trajectories, equipotentials, and other options. The number of particles, vectors, or streamlines, and the field strength are adjustable. Directions and source code are also included. This is an extension of a 3D Electric and Magnetic Field viewer from the same author.

Falstad, Paul

2004-07-13

334

3-D lithium ion microbattery  

NASA Astrophysics Data System (ADS)

The lithium-ion battery has emerged as a common power source for portable consumer electronics since its debut two decades ago. Due to the low atomic weight and high electrochemical activity of lithium chemistry, lithium-ion battery has a higher energy density as compared to other battery systems, such as Ni-Cd, Ni-MH, and lead-acid batteries. As a result, use of lithium-ion batteries enables the size of batteries to be effectively reduced without compromising capacity. More importantly, as battery size is reduced, it enhances the applications of portable electronics, increasing the convenience of use. The 3-D battery architecture described in the dissertation is believed to be a new paradigm for future batteries. The architecture features coupled 3-D electrodes to provide better charge/discharge kinetics and a higher charge capacity per footprint area. The overarching objective of this dissertation is to implement the 3-D architecture using the lithium-ion chemistry. The 3-D lithium-ion batteries are designed to provide high areal energy density without compromising power density. The dissertation is comprised of four interrelated sections. First, a simulation was conducted to identify key battery parameters and to define an ideal three-dimensional cell structure. The second part of the research involved identifying fabrication routes to build the 3-D electrode, which was the key design element in the 3-D paradigm. The third part of the dissertation was to correlate the electrode performance with its geometric features. In particular, the influence of aspect ratio was investigated. Lastly, an electrolyte/separator was designed and fabricated based on the existing 3-D electrode configuration. This enabled 3-D battery to be assembled.

Yeh, Yuting

335

Scaled 3D modeling of poly-phase tectonic deformation: A new analogue material for basement rock, with controlled variable strength.  

NASA Astrophysics Data System (ADS)

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.

Nieuwland, D. A.; Koekoek, G.; van Mechelen, D.; Papo, M.

2003-04-01

336

Static 3D image space  

NASA Astrophysics Data System (ADS)

As three-dimensional (3D) techniques continue to evolve from their humble beginnings-nineteenth century stereo photographs and twentieth century movies and holographs, the urgency for advancement in 3D display is escalating, as the need for widespread application in medical imaging, baggage scanning, gaming, television and movie display, and military strategizing increases. The most recent 3D developments center upon volumetric display, which generate 3D images within actual 3D space. More specifically, CSpace volumetric display generates a truly natural 3D image consisting of perceived width, height, and depth within the confines of physical space. Wireframe graphics enable viewers a 360-degree display without the use of additional visual aids. In this paper, research detailing the selection and testing of several rare earth, single-doped, fluoride crystals, namely 1%Er: NYF4, 2%Er: NYF4, 3%Er: NYF4 , 2%Er:KY3F10, and 2%Er:YLF, is introduced. These materials are the basis for CSpace display in a two-step twofrequency up-Conversion process. Significant determinants were tested and identified to aid in the selection of a suitable medium. Results show that 2%Er: NYF4 demonstrates good optical emitted power. Its superior level of brightness makes it the most suitable candidate for CSpace display. Testing also proved 2%Er: KY3F10 crystal might be a viable medium.

Koudsi, Badia; Sluss, Jim J., Jr.

2010-02-01

337

Space-time evolution of the seismo-tsunamigenic splay fault in the Nankai Trough  

NASA Astrophysics Data System (ADS)

Slip along splay faults that branch from subduction plate boundary megathrusts generates large earthquakes and tsunamis. Integrated Ocean Drilling Program (IODP) Expedition 316 examined the splay fault of the Nankai Trough offshore the Kii Peninsula, Japan. Combining geological and structural data from cores with detailed analysis of 3D seismic data and seabed topography around the shallow part of the splay fault, , we identified structural processes that vary both spatially and temporally during evolution of the splay fault. The ENE trending portion of the splay fault has been activite since the inception of faulting at about 1.95 Ma. The activity is well recorded in the deformation of the slope sediments, mass wasting deposits, and development of many slump scars. The activity is not limited to the region near the splay fault itself but also causes active folding of the accretionary prism in the hanging wall. The NE striking portion of the splay fault, in contrast, reflects early cessation of tectonic activity. Fault motion before 1.55 Ma may have been similar to that of ENE striking portion, but it was inactive between 1.55 - 1.24 Ma. During this period, the splay fault may have been folded. Modification of the dip angle and associated change in strike from ENE to NE may have prevented activity along the splay fault. This change in original fault geometry may have precipitated the formation of a secondary branch of the splay fault. Splay fault activity ceased after formation of the secondary branch. This section of the splay fault has been inactive over the last 1.24 Ma, and the NE-striking section of the splay fault has undergone regional uplift or tilting, perhaps related to drag along the overthrusting block further landward. The regional uplift and tilting, growth of the fault propagation or fault tip anticline expressed in deformation of the slope basin, slumping and shallow normal faulting of the slope sediments are all components of the total strain caused by motion along deeper sections of the splay fault.

Kimura, G.; Strasser, M.; Moore, G. F.; Screaton, E.; Curewitz, D.; Streiff, C. M.; Tobin, H.

2010-12-01

338

3D Imaging with Holographic Tomography  

NASA Astrophysics Data System (ADS)

There are two main types of tomography that enable the 3D internal structures of objects to be reconstructed from scattered data. The commonly known computerized tomography (CT) give good results in the x-ray wavelength range where the filtered back-projection theorem and Radon transform can be used. These techniques rely on the Fourier projection-slice theorem where rays are considered to propagate straight through the object. Another type of tomography called `diffraction tomography' applies in applications in optics and acoustics where diffraction and scattering effects must be taken into account. The latter proves to be a more difficult problem, as light no longer travels straight through the sample. Holographic tomography is a popular way of performing diffraction tomography and there has been active experimental research on reconstructing complex refractive index data using this approach recently. However, there are two distinct ways of doing tomography: either by rotation of the object or by rotation of the illumination while fixing the detector. The difference between these two setups is intuitive but needs to be quantified. From Fourier optics and information transformation point of view, we use 3D transfer function analysis to quantitatively describe how spatial frequencies of the object are mapped to the Fourier domain. We first employ a paraxial treatment by calculating the Fourier transform of the defocused OTF. The shape of the calculated 3D CTF for tomography, by scanning the illumination in one direction only, takes on a form that we might call a 'peanut,' compared to the case of object rotation, where a diablo is formed, the peanut exhibiting significant differences and non-isotropy. In particular, there is a line singularity along one transverse direction. Under high numerical aperture conditions, the paraxial treatment is not accurate, and so we make use of 3D analytical geometry to calculate the behaviour in the non-paraxial case. This time, we obtain a similar peanut, but without the line singularity.

Sheppard, Colin J. R.; Kou, Shan Shan

2010-04-01

339

An Image-Based Approach to Interactive 3D Virtual Exhibition  

Microsoft Academic Search

With the advance of 3D digitization and rendering technologies, interactive virtual exhibition can now be realized for applications\\u000a such as virtual museum, virtual showcase, and virtual mall. There are two major approaches to implementing a 3D interactive\\u000a virtual exhibition application. One approach is the geometry-based approach, which reconstructs geometric models for 3D objects\\u000a by using laser scanners or other 3D

Yi-ping Hung

2007-01-01

340

Evaluating the role of the Rhyolite Ridge Fault System in the Desert Peak Geothermal Field, NV: Boundary element modeling of fracture potential in proximity of fault slip  

NASA Astrophysics Data System (ADS)

Slip on the geometrically complex Rhyolite Ridge Fault System and associated local stresses in the Desert Peak Geothermal Field in Nevada, were modeled with the boundary element method (BEM) implemented in Poly3D. The impact of uncertainty in the fault geometry at depth, the tectonic stresses driving slip, and the potential ranges of frictional strength resisting slip on the likely predictions of fracture slip and formation in the surrounding volume due to these local stresses were systematically explored and quantified. The effect of parameter uncertainty was evaluated by determining the frequency distribution of model predicted values. Alternatively, Bayesian statistics were used to determine the best fitting values for parameters within a probability distribution derived from the difference of the model prediction from the observed data. This approach honors the relative contribution of uncertainties from all existing data that constrains the fault parameters. Lastly, conceptual models for different fault geometries and their evolution were heuristically explored and the predictions of local stress states were compared to available measurements of the local stresses, fault and fracture patterns at the surface and in boreholes, and the spatial extent of the geothermal field. The complex fault geometry leads to a high degree of variability in the locations experiencing stress states that promote fracture, but such locations generally correlate with the main injection and production wells at Desert Peak. In addition, the strongest and most common stress concentrations occur within relays between unconnected fault segments, and at bends and intersections in faults that connect overlapping fault segments associated with relays. The modeling approach in this study tests the conceptual model of the fault geometry at Desert Peak while honoring mechanical constants and available constraints on driving stresses and provides a framework that aids in geothermal exploration by predicting the spatial variations in stresses likely to cause and reactivate fractures necessary to sustain hydrothermal fluid flow. This approach also quantifies the relative sensitivity of such predictions to fault geometry, remote stress, and friction, and determines the best fitting model with its associated probability.

Swyer, Michael W.

341

Earthquake nucleation on dip-slip faults  

Microsoft Academic Search

The nucleation of unstable slip on a fault is of key importance in our understanding of the seismic cycle. We investigate how the asymmetric geometry of dip-slip faults affects the nucleation of unstable slip on such faults. Previous researchers have devoted much effort to understanding this nucleation process on geometrically simple faults, using a variety of frictional parameterizations. However, there

Chuanli Zhang; David D. Oglesby; Guanshui Xu

2004-01-01

342

LASTRAC.3d: Transition Prediction in 3D Boundary Layers  

NASA Technical Reports Server (NTRS)

Langley Stability and Transition Analysis Code (LASTRAC) is a general-purpose, physics-based transition prediction code released by NASA for laminar flow control studies and transition research. This paper describes the LASTRAC extension to general three-dimensional (3D) boundary layers such as finite swept wings, cones, or bodies at an angle of attack. The stability problem is formulated by using a body-fitted nonorthogonal curvilinear coordinate system constructed on the body surface. The nonorthogonal coordinate system offers a variety of marching paths and spanwise waveforms. In the extreme case of an infinite swept wing boundary layer, marching with a nonorthogonal coordinate produces identical solutions to those obtained with an orthogonal coordinate system using the earlier release of LASTRAC. Several methods to formulate the 3D parabolized stability equations (PSE) are discussed. A surface-marching procedure akin to that for 3D boundary layer equations may be used to solve the 3D parabolized disturbance equations. On the other hand, the local line-marching PSE method, formulated as an easy extension from its 2D counterpart and capable of handling the spanwise mean flow and disturbance variation, offers an alternative. A linear stability theory or parabolized stability equations based N-factor analysis carried out along the streamline direction with a fixed wavelength and downstream-varying spanwise direction constitutes an efficient engineering approach to study instability wave evolution in a 3D boundary layer. The surface-marching PSE method enables a consistent treatment of the disturbance evolution along both streamwise and spanwise directions but requires more stringent initial conditions. Both PSE methods and the traditional LST approach are implemented in the LASTRAC.3d code. Several test cases for tapered or finite swept wings and cones at an angle of attack are discussed.

Chang, Chau-Lyan

2004-01-01

343

3-D threat image projection  

NASA Astrophysics Data System (ADS)

Automated Explosive Detection Systems utilizing Computed Tomography perform a series X-ray scans of passenger bags being checked in at the airport, and produce various 2-D projection images and 3-D volumetric images of the bag. The determination as to whether the passenger bag contains an explosive and needs to be searched manually is performed through trained Transportation Security Administration screeners following an approved protocol. In order to keep the screeners vigilant with regards to screening quality, the Transportation Security Administration has mandated the use of Threat Image Projection on 2-D projection X-ray screening equipment used at all US airports. These algorithms insert visual artificial threats into images of the normal passenger bags in order to test the screeners with regards to their screening efficiency and their screening quality at determining threats. This technology for 2-D X-ray system is proven and is widespread amongst multiple manufacturers of X-ray projection systems. Until now, Threat Image Projection has been unsuccessful at being introduced into 3-D Automated Explosive Detection Systems for numerous reasons. The failure of these prior attempts are mainly due to imaging queues that the screeners pickup on, and therefore make it easy for the screeners to discern the presence of the threat image and thus defeating the intended purpose. This paper presents a novel approach for 3-D Threat Image Projection for 3-D Automated Explosive Detection Systems. The method presented here is a projection based approach where both the threat object and the bag remain in projection sinogram space. Novel approaches have been developed for projection based object segmentation, projection based streak reduction used for threat object isolation along with scan orientation independence and projection based streak generation for an overall realistic 3-D image. The algorithms are prototyped in MatLab and C++ and demonstrate non discernible 3-D threat image insertion into various luggage, and non discernable streak patterns for 3-D images when compared to actual scanned images.

Yildiz, Yesna O.; Abraham, Douglas Q.; Agaian, Sos; Panetta, Karen

2008-02-01

344

From 3D view to 3D print  

NASA Astrophysics Data System (ADS)

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.

Dima, M.; Farisato, G.; Bergomi, M.; Viotto, V.; Magrin, D.; Greggio, D.; Farinato, J.; Marafatto, L.; Ragazzoni, R.; Piazza, D.

2014-08-01

345

YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters  

NASA Astrophysics Data System (ADS)

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.

Schild, Jonas; Seele, Sven; Masuch, Maic

2012-03-01

346

Effects of fault propagation on superficial soils/gravel aquifer properties: The Chihshang Fault in Eastern Taiwan  

NASA Astrophysics Data System (ADS)

A mature bedrock fault zone generally consists of a fault core, a damage zone, and a surrounding host rock with different permeabilities, which mainly depend on the fracture density. However, near the surface, when an active thrust fault propagates from bedrocks into an unconsolidated surface cover, it results in a diffused fault zone, which may influence the hydraulic and mechanical properties around the fault zone. It is thus of great concern to understand to which extent surface soil/gravel hydraulic properties modifications by continuously active faulting can impact geotechnical projects in countries under active tectonic context, such as Taiwan, where active faults often are blinded beneath thick soil/gravel covers. By contrast, it is also interesting to decipher those fault-induced permeability modifications to estimate potential activity precursors to large earthquakes. Here, we combined a variety of measurements and analyses on the Chihshang fault, located at the plate suture between the Philippine Sea and Eurasian plates, which converge at a rapid rate of 8 cm/yr in Taiwan. At the Chinyuan site, the Chihshang fault is propagating from depth to emerge through thick alluvial deposits. We characterized the fault geometry and slip behavior at the shallow level by measuring and analyzing horizontal, vertical displacements, and groundwater table across the surface fault zone. The yielded fault dip of 45o in the shallow alluvium is consistent with the observations from surface ruptures and subsurface core logging. The 7-year-long groundwater table record shows that the piezometric level in the hanging wall is about 8 meter higher than that in the footwall in the summer; and about 10 meter higher in the winter. Repeated slug tests have been monthly conducted since 2007 to provide the average permeability within the fault zone and the presumably low-deformed zone outside of the diffused fault zone. Based on in-situ measurements at four wells across the fault zone, a 2-D modeling of pore pressure distribution around the fault zone is conducted using the finite-difference method (FLAC3D). The results showed that the permeability within the fault zone is 10-10 cm2 and outside of the fault zone is 10-8 cm2. The low permeable zone is estimated to be about 4-5 meters thick, and its location matches with the main fault structures mapped from geological and geodetic results. This low permeability fault zone acts as a hydraulic boundary, which explains the difference in the piezometric levels observed within the soil aquifer across the fault zone. This study provides a good natural analogue to permeability changes induced by clay smearing during soft sediments faulting. It also shows the significant impact of active thrust faults on soft sediments aquifer drainage.

Mu, C.; Lee, J.; guglielmi, Y.

2013-12-01

347

Speaking Volumes About 3-D  

NASA Technical Reports Server (NTRS)

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.

2002-01-01

348

PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITHOUT TURB3D)  

NASA Technical Reports Server (NTRS)

PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into five groups: 1) Grid Functions for grids, grid-checking, etc.; 2) Scalar Functions for contour or carpet plots of density, pressure, temperature, Mach number, vorticity magnitude, helicity, etc.; 3) Vector Functions for vector plots of velocity, vorticity, momentum, and density gradient, etc.; 4) Particle Trace Functions for rake-like plots of particle flow or vortex lines; and 5) Shock locations based on pressure gradient. TURB3D is a modification of PLOT3D which is used for viewing CFD simulations of incompressible turbulent flow. Input flow data consists of pressure, velocity and vorticity. Typical quantities to plot include local fluctuations in flow quantities and turbulent production terms, plotted in physical or wall units. PLOT3D/TURB3D includes both TURB3D and PLOT3D because the operation of TURB3D is identical to PLOT3D, and there is no additional sample data or printed documentation for TURB3D. Graphical capabilities of PLOT3D version 3.6b+ vary among the implementations available through COSMIC. Customers are encouraged to purchase and carefully review the PLOT3D manual before ordering the program for a specific computer and graphics library. There is only one manual for use with all implementations of PLOT3D, and although this manual generally assumes that the Silicon Graphics Iris implementation is being used, informative comments concerning other implementations appear throughout the text. With all implementations, the visual representation of the object and flow field created by PLOT3D consists of points, lines, and polygons. Points can be represented with dots or symbols, color can be used to denote data values, and perspective is used to show depth. Differences among implementations impact the program's ability to use graphical features that are based on 3D polygons, the user's ability to manipulate the graphical displays, and the user's ability to obtain alternate forms of output. The Apollo implementation of PLOT3D uses some of the capabilities of Apollo's 3-dimensional graphics hardware, but does not take advantage of the s

Buning, P.

1994-01-01

349

PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITH TURB3D)  

NASA Technical Reports Server (NTRS)

PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into five groups: 1) Grid Functions for grids, grid-checking, etc.; 2) Scalar Functions for contour or carpet plots of density, pressure, temperature, Mach number, vorticity magnitude, helicity, etc.; 3) Vector Functions for vector plots of velocity, vorticity, momentum, and density gradient, etc.; 4) Particle Trace Functions for rake-like plots of particle flow or vortex lines; and 5) Shock locations based on pressure gradient. TURB3D is a modification of PLOT3D which is used for viewing CFD simulations of incompressible turbulent flow. Input flow data consists of pressure, velocity and vorticity. Typical quantities to plot include local fluctuations in flow quantities and turbulent production terms, plotted in physical or wall units. PLOT3D/TURB3D includes both TURB3D and PLOT3D because the operation of TURB3D is identical to PLOT3D, and there is no additional sample data or printed documentation for TURB3D. Graphical capabilities of PLOT3D version 3.6b+ vary among the implementations available through COSMIC. Customers are encouraged to purchase and carefully review the PLOT3D manual before ordering the program for a specific computer and graphics library. There is only one manual for use with all implementations of PLOT3D, and although this manual generally assumes that the Silicon Graphics Iris implementation is being used, informative comments concerning other implementations appear throughout the text. With all implementations, the visual representation of the object and flow field created by PLOT3D consists of points, lines, and polygons. Points can be represented with dots or symbols, color can be used to denote data values, and perspective is used to show depth. Differences among implementations impact the program's ability to use graphical features that are based on 3D polygons, the user's ability to manipulate the graphical displays, and the user's ability to obtain alternate forms of output. The Apollo implementation of PLOT3D uses some of the capabilities of Apollo's 3-dimensional graphics hardware, but does not take advantage of the s

Buning, P.

1994-01-01

350

Complexity and segmentation of the Seattle Fault System  

Microsoft Academic Search

Much debate and uncertainty remains regarding the location and geometry of crustal faults in the Puget Lowland and their roles in accommodating regional tectonic strain. Recent models for one prominent fault, the Seattle Fault (SF), range from a steeply dipping reverse fault to a low-angle thrust, with little consensus as to the preferred geometry. These SF models share several important

K. M. Keranen; R. E. Wells; B. L. Sherrod; R. J. Blakely; C. S. Weaver

2009-01-01

351

3D reconstruction of a micro pipette tip  

Microsoft Academic Search

Glass micro pipettes have been widely used for patch clamping. Although many researchers agree that the shape and roundness of pipette tip are important for cell grabbing and gigaseal formation, no numerical values of the geometry have been reported so far. In this research, a FIB\\/SEM system was used as a nano tomography tool to obtain the 3D shape of

H. Ostadi; M. Malboubi; P. D. Prewett; K. Jiang

2009-01-01

352

Modeling the Properties of 3D Woven Composites  

SciTech Connect

An extensive study has been completed of the internal geometry, the mechanisms of failure, and the micromechanics of local failure events in graphite/epoxy composites with three dimensional (3D) woven reinforcement. This work has led to the development of models for predicting elastic constants, strength, notch sensitivity, and fatigue life. A summary is presented here.

Cox, B.N.

1995-10-01

353

METHODS OF PARALLEL VOXEL MANIPULATION FOR 3D DIGITAL PRINTING  

Microsoft Academic Search

A novel digital printing concept is explored for desktop fabrication of multi- material objects with arbitrary 3D geometry. Digital objects are composed of many discrete, self-aligning voxels instead of continuous (analog) deposition techniques. Overall accuracy is determined by the individual voxels instead of the printer, and digital properties such as perfect replication and error correction are physically meaningful. The key

Jonathan Hiller; Hod Lipson

354

On Modeling Bonds in Fused, Porous Networks: 3D Simulations  

E-print Network

or elements. Here we expand on previous work in 2D network behavior (reviewed in [1]) by focusing on the geometry and response of 3D interconnects between cylindrical elements. We present computational results nanotube mat are among the newest engineered materials constructed in this way. Applications

Sastry, Ann Marie

355

Particle trajectories and acceleration during 3D fan reconnection  

E-print Network

Context. The primary energy release in solar flares is almost certainly due to magnetic reconnection, making this a strong candidate as a mechanism for particle acceleration. While particle acceleration in 2D geometries has been widely studied, investigations in 3D are a recent development. Two main classes of reconnection regimes at a 3D magnetic null point have been identified: fan and spine reconnection Aims. Here we investigate particle trajectories and acceleration during reconnection at a 3D null point, using a test particle numerical code, and compare the efficiency of the fan and spine regimes in generating an energetic particle population. Methods. We calculated the time evolution of the energy spectra. We discuss the geometry of particle escape from the two configurations and characterise the trapped and escaped populations. Results. We find that fan reconnection is less efficent than spine reconnection in providing seed particles to the region of strong electric field where acceleration is possible...

Dalla, S; 10.1051/0004-6361:200809771

2008-01-01

356

Petal, terrain & airbags - 3D  

NASA Technical Reports Server (NTRS)

Portions of the lander's deflated airbags and a petal are at the lower area of this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. The metallic object at lower right is part of the lander's low-gain antenna. This image is part of a 3D 'monster

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

1997-01-01

357

Influence of pre-existing fabrics on fault kinematics and rift geometry of interacting segments: Analogue models based on the Albertine Rift (Uganda), Western Branch-East African Rift System  

NASA Astrophysics Data System (ADS)

This study aims at showing how far pre-existing crustal weaknesses left behind by Proterozoic mobile belts, that pass around cratonic Archean shields (Tanzania Craton to the southeast and Congo Craton to the northwest), control the geometry of the Albertine Rift. Focus is laid on the development of the Lake Albert and Lake Edward/George sub-segments and between them the greatly uplifted Rwenzori Mountains, a horst block located within the rift and whose highest peak rises to >5000 m above mean sea level. In particular we study how the southward propagating Lake Albert sub-segment to the north interacts with the northward propagating Lake Edward/George sub-segment south of it, and how this interaction produces the structures and geometry observed in this section of the western branch of the East African Rift, especially within and around the Rwenzori horst. We simulate behaviour of the upper crust by conducting sandbox analogue experiments in which pre-cut rubber strips of varying overstep/overlap connected to a basal sheet and oriented oblique and/or orthogonal to the extension vector, are placed below the sand-pack. The points of connection present velocity discontinuities to localise deformation, while the rubber strips represent ductile domain affected by older mobile belts. From fault geometry of developing rift segments in plan view and section cuts, we study kinematics resulting from a given set of boundary conditions, and results are compared with the natural scenario. Three different basal model-configurations are used to simulate two parallel rifts that propagate towards each other and interact. Wider overstep (model SbR3) produces an oblique transfer zone with deep grabens (max. 7.0 km) in the adjoining segments. Smaller overlap (model SbR4) ends in offset rift segments without oblique transfer faults to join the two, and produces moderately deep grabens (max. 4.6 km). When overlap doubles the overstep (model SbR5), rifts propagate sub-orthogonal to the extension direction and form shallow valleys (max. 2.9 km). Relative ratios of overlap/overstep between rift segments dictate the kind of transition zone that develops and whether or not a block (like the Rwenzoris) is captured and rotates; hence determining the end-member geometry. Rotation direction is controlled by pre-existing fabrics. Fault orientation, fault kinematics, and block rotation (once in play) reinforce each other; and depending on the local kinematics, different parts of a captured block may rotate with variable velocities but in the same general direction. Mechanical strength anisotropy of pre-structured crust only initially centres fault nucleation and propagation parallel to the grain of weakness of the basement, but at later stages of a protracted period of crustal extension, such boundaries are locally defied.

Aanyu, K.; Koehn, D.

2011-02-01

358

A support-operator method for 3-D rupture dynamics  

Microsoft Academic Search

We present a numerical method to simulate spontaneous shear crack propagation within a heterogeneous, 3-D, viscoelastic medium. Wave motions are computed on a logically rectangular hexahedral mesh, using the generalized finite-difference method of Support Operators (SOM). This approach enables modelling of non-planar surfaces and non-planar fault ruptures. Our implementation, the Support Operator Rupture Dynamics (SORD) code, is highly scalable, enabling

Geoffrey P. Ely; Steven M. Day; Jean-Bernard Minster

2009-01-01

359

3D Fire Spread Animations  

NSDL National Science Digital Library

These excellent animations overlay animations of fire spread on 3D terrain that incorporates satellite imagery. A timeline shows the animation's current time relative to the fire occurrence, and an inset map provides an overhead view of the fire on a map that shows fuels by location. Animations are available for several wildfires that occurred in California.

Johson, Harry D.; University, San D.

360

Fault Motion  

NSDL National Science Digital Library

This collection of animations provides elementary examples of fault motion intended for simple demonstrations. Examples include dip-slip faults (normal and reverse), strike-slip faults, and oblique-slip faults.