These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Paleoseismic study of the Cathedral Rapids fault in the northern Alaska Range near Tok, Alaska  

NASA Astrophysics Data System (ADS)

The Cathedral Rapids fault extends ~40 km between the Tok and Robertson River valleys and is the easternmost fault in a series of active south-dipping imbricate thrust faults which bound the northern flank of the Alaska Range. Collectively, these faults accommodate a component of convergence transferred north of the Denali fault and related to the westward (counterclockwise) rotation of the Wrangell Block driven by relative Pacific/North American plate motion along the eastern Aleutian subduction zone and Fairweather fault system. To the west, the system has been defined as the Northern Foothills Fold and Thrust Belt (NFFTB), a 50-km-wide zone of east-west trending thrust faults that displace Quaternary deposits and have accommodated ~3 mm/yr of shortening since latest Pliocene time (Bemis, 2004). Over the last several years, the eastward extension of the NFFTB between Delta Junction and the Canadian border has been studied by the Alaska Division of Geological & Geophysical Surveys to better characterize faults that may affect engineering design of the proposed Alaska-Canada natural gas pipeline and other infrastructure. We summarize herein reconnaissance field observations along the western part of the Cathedral Rapids fault. The western part of the Cathedral Rapids fault extends 21 km from Sheep Creek to Moon Lake and is characterized by three roughly parallel sinuous traces that offset glacial deposits of the Illinoian to early Wisconsinan Delta glaciations and the late Wisconsinan Donnelly glaciation, as well as, Holocene alluvial deposits. The northern trace of the fault is characterized by an oversteepened, beveled, ~2.5-m-high scarp that obliquely cuts a Holocene alluvial fan and projects into the rangefront. Previous paleoseismic studies along the eastern part of the Cathedral Rapids fault and Dot “T” Johnson fault indicate multiple latest Pleistocene and Holocene earthquakes associated with anticlinal folding and thrust faulting (Carver et al., 2010). Combined with this previous work, our paleoseismic assessment of the western Cathedral Rapids fault, including trenching in fall 2010, may contribute to increasing the understanding of the style and timing of deformation for faults bounding the northern flank of the Alaska Range. These data may also provide insight into the eastern extent of the NFFTB and its role in accommodating regional shortening.

Koehler, R. D.; Farrell, R.; Carver, G. A.

2010-12-01

2

Winchester Cathedral: East End  

Microsoft Academic Search

The eastern end of Winchester Cathedral photographed from a garden off of Colebrook St. The Winchester Cathedral has the longest nave of all the medieval cathedrals in England. This view show’s the cathedral’s gothic style architecture. While the cathedral is still in use as a church, it is also a popular tourist destination for visitors.

Chet Smolski

1973-01-01

3

Winchester Cathedral: Interior, Nave  

Microsoft Academic Search

The nave of Winchester Cathedral is the longest of the medieval cathedrals in England. The nave was remodeled in 1394, and the original Norman style was modified as the building evolved into that of the gothic and Romanesque styles.

Chet Smolski

1973-01-01

4

St. Paul's Cathedral  

NSDL National Science Digital Library

Perhaps one of the finest neo-Classical cathedrals in the world, the current St. Paul's cathedral is an example of the outstanding architecture of Christopher Wren, and a testimony to his dogged persistence and passion for his life's work. In keeping with the attention to detail that is indicative of Mr. Wren's work, the St. Paul's Web site has detailed information on visiting the cathedral, the various musical performances that it hosts, and an interactive timeline detailing the history of St. Paul's that extends back to the year 604. Along with this information, the site also tells visitors about upcoming events at the cathedral, along with an extensive online gift shop that offers a diverse set of St. Paul's related material for purchase.

5

Earthquake Resistant Cathedral in Chile  

USGS Multimedia Gallery

A cathedral in the central square of Chillán, Chile replaces the ancient cathedral that collapsed during the strong earthquake of 1939. This modern structure was constructed with earthquake resistance as the primary consideration. The only damage caused by the M 8.8 earthquake on Feb. 27, 2010 was b...

2010-03-30

6

An earthquake mechanism based on rapid sealing of faults  

USGS Publications Warehouse

RECENT seismological, heat flow and stress measurements in active fault zones such as the San Andreas have led to the suggestion1,2 that such zones can be relatively weak. One explanation for this may be the presence of overpressured fluids along the fault3-5, which would reduce the shear stress required for sliding by partially 'floating' the rock. Although several mechanisms have been proposed for overpressurizing fault fluids3,4,6,7, we recall that 'pressure seals' are known to form in both sedimentary8 and igneous9 rocks by the redistribution of materials in solution; the formation of such a seal along the boundaries of a fault will prevent the communication of fluids between the porous, deforming fault zone and the surrounding country rock. Compaction of fault gouge, under hydrostatic loading and/or during shear, elevates pore pressure in the sealed fault and allows sliding at low shear stress. We report the results of laboratory sliding experiments on granite, which demonstrate that the sliding resistance of faults can be significantly decreased by sealing and compaction. The weakening that results from shear-induced compaction can be rapid, and may provide an instability mechanism for earthquakes.

Blanpied, M.L.; Lockner, D.A.; Byerlee, J.D.

1992-01-01

7

The Design Method of Gothic Cathedrals  

Microsoft Academic Search

This is a presentation of the graphostatic design method of XII-XIV century French Gothic cathedrals, particularly of the construction of the longitudinal and cross sections, the west cathedral facade and the line of thrust in pointed vault arches.

M. M. Rivin; A. I. Toporov

2000-01-01

8

Magnificent Flying Machine--A Cathedral to Technology 1 Magnificent  

E-print Network

: a certain wasp-waisted soft drink bottle epitomizes America of the 1950s; the outline of a gothic cathedralMagnificent Flying Machine--A Cathedral to Technology 1 Magnificent Flying Machine-- A Cathedral. 2 Magnificent Flying Machine--A Cathedral to Technology Magnificent Flying Machine-- A Cathedral

9

Rapid Determination of Near-Fault Earthquake Deformation Using LIDAR  

NASA Astrophysics Data System (ADS)

The 2005 airborne lidar survey of the southern San Andreas, San Jacinto and Banning faults (the "B4 Survey") has delivered a high-resolution digital elevation model (DEM) of 1100 km of the most seismically active fault systems in southern California for the express purpose of providing a baseline for post-earthquake slip determination. We used this survey as a testbed to experiment with processing algorithms for rapid estimation of near-fault ground deformation. One algorithm uses simultaneous cross correlation of both topography and backscatter intensity from pre-earthquake and simulated post-earthquake LIDAR datasets. We show robust recovery of the direction and magnitude of an applied synthetic slip of 5 m in the horizontal and 0.5 m in the vertical within the test area, with excellent discrimination between areas with and without applied slip. Another algorithm relies on an evolutionary programming approach, which is more robust in the presence of multiple minima of the solution manifold, but requires substantially more processing power. Our results indicate that one should be able to recover slip to accuracies of better than 20 cm in the horizontal and 1 cm in the vertical, at a spatial resolution of ?15 m for lidar datasets with sample densities as low as 0.5 points/m2.

Borsa, A. A.; Minster, J. H.

2011-12-01

10

Age of Cathedrals R. Howard Bloch  

E-print Network

Age of Cathedrals R. Howard Bloch Paris, July 6-August 10, 2013 Humanities S267, French S305 of course: reading, worksheets, paper, V2 Class Server. Introduction to Romanesque and Gothic, financing the cathedral, the senses, and spirituality. Week 2 Notre-Dame de Paris Reading: Abelard's History

11

Rapid Determination of Near-Fault Earthquake Deformation using LIDAR  

Microsoft Academic Search

The 2005 airborne lidar swath mapping (ALSM) survey of the southern San Andreas, San Jacinto and Banning faults (the ``B4 survey'') delivered a high-resolution digital elevation model of 1100 km of the most seismically active fault systems in southern California for the express purpose of providing a baseline for post-earthquake slip determination. We used the B4 survey as a testbed

A. A. Borsa; J. H. Minster

2009-01-01

12

The Gothic Cathedral: An Immersive Information Visualization Space Francis T. Marchese  

E-print Network

The Gothic Cathedral: An Immersive Information Visualization Space Francis T. Marchese Computer the Middle Ages Gothic cathedrals were immersive information spaces which supported religious education. THE CATHEDRAL AS VIRTUAL ENVIRONMENT The Gothic cathedral was the nexus of Christian religious practice

Marchese, Francis

13

Cathedral house & crocker fence, Taylor Street east and north ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Cathedral house & crocker fence, Taylor Street east and north elevations, perspective view from the northeast - Grace Cathedral, George William Gibbs Memorial Hall, 1051 Taylor Street, San Francisco, San Francisco County, CA

14

Age of Cathedrals R. Howard Bloch  

E-print Network

The rise of communes, the role of masons and guilds, the industry of cathedral building; the history to be determined, Sainte-Chapelle, program of sacred music, 7:00 p.m., 4 Blvd. du Palais, Paris 1e. #12;Week 4

15

Building Cathedrals and Breaking down Reinforced Concrete Walls  

E-print Network

Building Cathedrals and Breaking down Reinforced Concrete Walls Michel Brou´e Institut Henri distinction between great mathematicians Concrete walls breakers Michel Brou´e (Institut Henri Poincar´e) John Concrete walls breakers Cathedrals builders Michel Brou´e (Institut Henri Poincar´e) John Thompson

Broué, Michel - Institut de Mathématiques de Jussieu, Université Paris 7

16

A Teleseismic Study of the 2002 Denali Fault, Alaska, Earthquake and Implications for Rapid Strong-Motion Estimation  

Microsoft Academic Search

Slip histories for the 2002 M7.9 Denali fault, Alaska, earthquake are de- rived rapidly from global teleseismic waveform data. In phases, three models improve matching waveform data and recovery of rupture details. In the first model (Phase I), analogous to an automated solution, a simple fault plane is fixed based on the preliminary Harvard Centroid Moment Tensor mechanism and the

Chen Ji; Don V. Helmberger; David J. Wald

2004-01-01

17

Ad Orientem: the Orientation of Gothic Cathedrals of France  

E-print Network

Here the orientation of the Gothic cathedrals in France is discussed and investigated using the satellite maps. Except a few of them, these buildings have the apse facing the rising sun, according to a practice adopted during the middle age.

Sparavigna, Amelia Carolina

2012-01-01

18

Rapid Determination of Near-Fault Earthquake Deformation Using Differential LiDAR  

E-print Network

Determination of Near-Fault Earthquake Deformation Usingnear-field control on fault slip for moderate-to-large magnitude earthquakes,near-fault ground deformation using simultaneous cross correlation of both topography and backscatter intensity from pre-earthquake

Borsa, Adrian Antal; Minster, Jean Bernard

2012-01-01

19

JOURNAL OF GEOPHYSICAL RESEARCH: SOLID EARTH, VOL. 118, 117, doi:10.1002/jgrb.50236, 2013 Rapid strain accumulation on the Ashkabad fault (Turkmenistan)  

E-print Network

strain accumulation on the Ashkabad fault (Turkmenistan) from atmosphere-corrected InSAR R. J. Walters,1, and B. Parsons (2013), Rapid strain accumulation on the Ashkabad fault (Turkmenistan) from atmosphere-lateral Ashkabad strike-slip fault is located along the northeastern edge of the Kopeh Dagh moun- tains on the Iran-Turkmenistan

20

University of Pittsburgh 407 B Cathedral of Learning  

E-print Network

plan to receive benefits at the Office of Veterans Services. __________ Initial 10. I understandUniversity of Pittsburgh 407 B Cathedral of Learning Phone: 412-624-3213 Fax: 412-624-4766 veterans@pitt.edu Office of Veterans Services ENROLLMENT CERTIFICATION REQUEST FORM PART 1 ­ STUDENT INFORMATION 1. NAME

Jiang, Huiqiang

21

University of Pittsburgh 407 B Cathedral of Learning  

E-print Network

benefits at the Office of Veterans Services. __________ Initial 10. I understand that it is myUniversity of Pittsburgh 407 B Cathedral of Learning Phone: 412-624-3213 Fax: 412-624-4766 veterans@pitt.edu Office of Veterans Services ENROLLMENT CERTIFICATION REQUEST FORM PART 1 ­ STUDENT INFORMATION 1. NAME

Jiang, Huiqiang

22

A teleseismic study of the 2002 Denali fault, Alaska, earthquake and implications for rapid strong-motion estimation  

USGS Publications Warehouse

Slip histories for the 2002 M7.9 Denali fault, Alaska, earthquake are derived rapidly from global teleseismic waveform data. In phases, three models improve matching waveform data and recovery of rupture details. In the first model (Phase I), analogous to an automated solution, a simple fault plane is fixed based on the preliminary Harvard Centroid Moment Tensor mechanism and the epicenter provided by the Preliminary Determination of Epicenters. This model is then updated (Phase II) by implementing a more realistic fault geometry inferred from Digital Elevation Model topography and further (Phase III) by using the calibrated P-wave and SH-wave arrival times derived from modeling of the nearby 2002 M6.7 Nenana Mountain earthquake. These models are used to predict the peak ground velocity and the shaking intensity field in the fault vicinity. The procedure to estimate local strong motion could be automated and used for global real-time earthquake shaking and damage assessment. ?? 2004, Earthquake Engineering Research Institute.

Ji, C.; Helmberger, D.V.; Wald, D.J.

2004-01-01

23

Finite-fault source inversion using teleseismic P waves: simple parameterization and rapid analysis  

USGS Publications Warehouse

We examine the ability of teleseismic P waves to provide a timely image of the rupture history for large earthquakes using a simple, 2D finite?fault source parameterization. We analyze the broadband displacement waveforms recorded for the 2010 Mw~7 Darfield (New Zealand) and El Mayor?Cucapah (Baja California) earthquakes using a single planar fault with a fixed rake. Both of these earthquakes were observed to have complicated fault geometries following detailed source studies conducted by other investigators using various data types. Our kinematic, finite?fault analysis of the events yields rupture models that similarly identify the principal areas of large coseismic slip along the fault. The results also indicate that the amount of stabilization required to spatially smooth the slip across the fault and minimize the seismic moment is related to the amplitudes of the observed P waveforms and can be estimated from the absolute values of the elements of the coefficient matrix. This empirical relationship persists for earthquakes of different magnitudes and is consistent with the stabilization constraint obtained from the L?curve in Tikhonov regularization. We use the relation to estimate the smoothing parameters for the 2011 Mw 7.1 East Turkey, 2012 Mw 8.6 Northern Sumatra, and 2011 Mw 9.0 Tohoku, Japan, earthquakes and invert the teleseismic P waves in a single step to recover timely, preliminary slip models that identify the principal source features observed in finite?fault solutions obtained by the U.S. Geological Survey National Earthquake Information Center (USGS/NEIC) from the analysis of body? and surface?wave data. These results indicate that smoothing constraints can be estimated a priori to derive a preliminary, first?order image of the coseismic slip using teleseismic records.

Mendoza, C.; Hartzell, S.

2013-01-01

24

Strain on the San Andreas fault near Palmdale, California: Rapid, aseismic change  

USGS Publications Warehouse

Frequently repeated strain measurements near Palmdale, California, during the period from 1971 through 1980 indicate that, in addition to a uniform accumulation of right-lateral shear strain (engineering shear, 0.35 microradian per year) across the San Andreas fault, a 1-microstrain contraction perpendicular to the fault that accumulated gradually during the interval 1974 through 1978 was aseismically released between February and November 1979. Subsequently (November 1979 to March 1980), about half of the contraction was recovered. This sequence of strain changes can be explained in terms of south-southwestward migration of a slip event consisting of the south-southwestward movement of the upper crust on a horizontal detachment surface at a depth of 10 to 30 kilometers. The large strain change in 1979 corresponds to the passage of the slip event beneath the San Andreas fault. Copyright ?? 1980 AAAS.

Savage, J. C.; Prescott, W. H.; Lisowski, M.; King, N. E.

1981-01-01

25

Strain on the san andreas fault near palmdale, california: rapid, aseismic change.  

PubMed

Frequently repeated strain measurements near Palmdale, California, during the period from 1971 through 1980 indicate that, in addition to a uniform accumulation of right-lateral shear strain (engineering shear, 0.35 microradian per year) across the San Andreas fault, a 1-microstrain contraction perpendicular to the fault that accumulated gradually during the interval 1974 through 1978 was aseismically released between February and November 1979. Subsequently (November 1979 to March 1980), about half of the contraction was recovered. This sequence of strain changes can be explained in terms of south-southwestward migration of a slip event consisting of the south-southwestward movement of the upper crust on a horizontal detachment surface at a depth of 10 to 30 kilometers. The large strain change in 1979 corresponds to the passage of the slip event beneath the San Andreas fault. PMID:17731244

Savage, J C; Prescott, W H; Lisowski, M; King, N E

1981-01-01

26

Electrical structure of the tectonically active Kalabsha Fault, Aswan, Egypt [rapid communication  

NASA Astrophysics Data System (ADS)

In this work, we use the magnetotelluric (MT) method to detect geoelectrical conductivity anomalies in the Earth's crust and link them to local seismic activity. This application affords the unusual opportunity to study the percolation of water from a lake into a fault system and its effect on the induced seismicity. MT measurements were carried out in the period range 0.0046-420 s at nine sites along a 15 km-long North-South profile crossing the Kalabsha Fault, on the western bank of Lake Aswan. Data were analysed by 2D simultaneous inversion of both polarisations. The resulting model is compared with the local seismicity map and reveals the conductive signature of the fault, as well as geological and tectonic stresses prevailing in the Aswan area. Our MT investigations show the following features: The measured MT strike aligns with the seismic epicentre axis corresponding to the Kalabsha Fault. While crossing the Fault, enhanced conductivity is found down to depths of 5 km on a 1-2 km profile segment. At mid-crustal depths (20 km), a very high conductive body is found to coincide with the main seismic cluster in the Aswan area. These observations indicate that seismic activity and high electrical conductivity are related. The link between them is the presence of crustal fluids which are presumably the cause of the high conductivity observed. Their presence is also required to trigger the observed seismicity. In addition, we explain the lower conductivity of the local upper crust in terms of stress-modulated rock porosity. We believe that these results are of general significance, as they could explain the mid-crustal seismicity of tectonically active zones.

Mekkawi, Mahmoud; Schnegg, Pierre-André; Arafa-Hamed, Tarek; Elathy, Essam

2005-12-01

27

"Friends" of Anglican Cathedrals: Norms and Values. Befriending, Friending or Misnomer?  

ERIC Educational Resources Information Center

Loyal supporters of Anglican cathedrals first subscribed to "Friends" associations in the late 1920s. Yet, in 1937, a journalist in "The Times" portrayed cathedrals as a "queer thing to be a friend of." Drawing on theories of friendship from a range of disciplines, and surveys of what has been proclaimed in the public…

Muskett, Judith A.

2013-01-01

28

A Gothic masterpiece in the Levant. Saint Nicholas Cathedral, Famagusta, North Cyprus  

Microsoft Academic Search

This article presents a very brief historical overview, and contemporary description, of the Cathedral of St. Nicholas in Famagusta in Northern Cyprus. In the light of the changing political situation in that island it invites scholarship in a range of disciplines to the cathedral and to other historic landmarks within the old city walls. Scholars interested might include: art historians,

Michael Walsh

2005-01-01

29

The archaeological site of the cathedral of Saint Peter (Saint?Pierre), Geneva  

Microsoft Academic Search

Over the last ten years, archaeological investigation of the Cathedral of Saint?Pierre at Geneva has been carried out in conjunction with the restoration of the building, allowing the origins of the episcopal group to be defined and its architectural evolution studied. The group, complete as early as the fourth century, consists of two cathedrals on either side of a baptistry,

Charles Bonnet

1987-01-01

30

Rapid, decimeter-resolution fault zone topography mapped with Structure from Motion  

NASA Astrophysics Data System (ADS)

Recent advances in the generation of high-resolution topography have revolutionized our ability to detect subtle geomorphic features related to ground-rupturing earthquakes. Currently, the most popular topographic mapping methods are airborne Light Detection And Ranging (LiDAR) and terrestrial laser scanning (TLS). Though powerful, these laser scanning methods have some inherent drawbacks: airborne LiDAR is expensive and can be logistically complicated, while TLS is time consuming even for small field sites and suffers from patchy coverage due to its restricted field-of-view. An alternative mapping technique, called Structure from Motion (SfM), builds upon traditional photogrammetry to reproduce the topography and texture of a scene from photographs taken at varying viewpoints. The improved availability of cheap, unmanned aerial vehicles (UAVs) as camera platforms further expedites data collection by covering large areas efficiently with optimal camera angles. Here, we introduce a simple and affordable UAV- or balloon-based SfM mapping system which can produce dense point clouds and sub-decimeter resolution digital elevation models (DEMs) registered to geospatial coordinates using either the photograph's GPS tags or a few ground control points across the scene. The system is ideally suited for studying ruptures of prehistoric, historic, and modern earthquakes in areas of sparse or low-lying vegetation. We use two sites from southern California faults to illustrate. The first is the ~0.1 km2 Washington Street site, located on the Banning strand of the San Andreas fault near Thousand Palms. A high-resolution DEM with ~700 point/m2 was produced from 230 photos collected on a balloon platform flying at 50 m above the ground. The second site is the Galway Lake Road site, which spans a ~1 km strip of the 1992 Mw 7.3 Landers earthquake on the Emerson Fault. The 100 point/m2 DEM was produced from 267 photos taken with a balloon platform at a height of 60 m above the ground. We compare our SfM results to existing airborne LiDAR or TLS datasets. Each SfM survey required less than 2 hours for setup and data collection, an allotment much lower than that required for TLS data collection, given the size of the sites. Processing time is somewhat slower, but depends on the quality of the DEM desired and is almost fully automated. The SfM point cloud densities we present are comparable to TLS but exceed the density of most airborne LiDAR and the orthophotos (texture maps) from the SfM are valuable complements to the DEMs. The SfM topography illuminates features along the faults that can be used to measure offsets from past ruptures, offering the potential to enhance regional seismic hazard analyses.

Johnson, K. L.; Nissen, E.; Saripalli, S.; Arrowsmith, R.; McGarey, P.; Scharer, K. M.; Williams, P. L.

2013-12-01

31

RAPID  

Cancer.gov

Rapid Access to Preventive Intervention Development (RAPID) Program About RAPID Description and Objectives of the Program Oversight RAPID Is Not... Frequently Asked Questions Application Information Format of Applications Address for Applications

32

Real-time magnitude estimation and rapid fault characterization with GPS data for Earthquake Early Warning applications  

NASA Astrophysics Data System (ADS)

The combined use of seismic and geodetic observations is now a common practice for finite-fault modeling and seismic source parametrization. With the advent of high-rate 1Hz GPS stations the seismological community has begun to look at ways to include GPS data in Earthquake Early Warning (EEW) algorithms. GPS stations record ground displacement without any risk of saturating or need for baseline or other corrections. Thus, geodetic displacement timeseries complement the high-frequency information provided by seismic data. In the standard approaches to early warning, the initial portion of the P-wave signal is used to rapidly characterize the earthquake magnitude and to predict the expected ground shaking at a target site, before damaging waves arrive. Whether the final magnitude of an earthquake can be predicted while the rupture process is underway, still represents a controversial issue; the point is that the limitations of the standard approaches when applied to giant earthquakes have become evident after the experience of the Mw 9.0, 2011 Tohoku-Oki earthquake. Here we explore the application of GPS data to EEW and investigate whether the co-seismic ground deformation can be used to provide fast and reliable magnitude estimations. We implemented an algorithm to extract the permanent static offset from GPS displacement timeseries; the static displacement is then used to invert for the slip distribution on the fault plane, using a constant-slip, rectangular source embedded in a homogeneous half-space. We developed an efficient real-time static slip inversion scheme for both the rapid determination of the event size and for the near real-time estimation of the rupture area. This would allow for a correct evaluation of the expected ground shaking at the target sites, which represents, without doubt, the most important aspect of the practical implementation of an early warning system and the most relevant information to be provided to non-expert end-users. The strategy we propose is fairly robust and does not need any predefined geometry or restrictive prior assumptions; the starting model is a simple fault plane divided into a limited number of patches. The geometry and dimensions are determined as soon as the first magnitude estimation from near-field seismic stations is available. The methodology is expected to be suitable for any seismically active area and can be easily incorporated into a real-time Earthquake Early Warning System.

Colombelli, S.; Allen, R. M.; Zollo, A.

2012-12-01

33

The role of dyking and fault control in the rapid onset of eruption at Chaitén volcano, Chile.  

PubMed

Rhyolite is the most viscous of liquid magmas, so it was surprising that on 2?May 2008 at Chaitén Volcano, located in Chile's southern Andean volcanic zone, rhyolitic magma migrated from more than 5?km depth in less than 4?hours (ref.?1) and erupted explosively with only two days of detected precursory seismic activity. The last major rhyolite eruption before that at Chaitén was the largest volcanic eruption in the twentieth century, at Novarupta volcano, Alaska, in 1912. Because of the historically rare and explosive nature of rhyolite eruptions and because of the surprisingly short warning before the eruption of the Chaitén volcano, any information about the workings of the magmatic system at Chaitén, and rhyolitic systems in general, is important from both the scientific and hazard perspectives. Here we present surface deformation data related to the Chaitén eruption based on radar interferometry observations from the Japan Aerospace Exploration Agency (JAXA) DAICHI (ALOS) satellite. The data on this explosive rhyolite eruption indicate that the rapid ascent of rhyolite occurred through dyking and that melt segregation and magma storage were controlled by existing faults. PMID:22012396

Wicks, Charles; de la Llera, Juan Carlos; Lara, Luis E; Lowenstern, Jacob

2011-10-20

34

The role of dyking and fault control in the rapid onset of eruption at Chaitén Volcano, Chile  

USGS Publications Warehouse

Rhyolite is the most viscous of liquid magmas, so it was surprising that on 2?May 2008 at Chaitén Volcano, located in Chile’s southern Andean volcanic zone, rhyolitic magma migrated from more than 5?km depth in less than 4?hours and erupted explosively with only two days of detected precursory seismic activity. The last major rhyolite eruption before that at Chaitén was the largest volcanic eruption in the twentieth century, at Novarupta volcano, Alaska, in 1912. Because of the historically rare and explosive nature of rhyolite eruptions and because of the surprisingly short warning before the eruption of the Chaitén volcano, any information about the workings of the magmatic system at Chaitén, and rhyolitic systems in general, is important from both the scientific and hazard perspectives. Here we present surface deformation data related to the Chaitén eruption based on radar interferometry observations from the Japan Aerospace Exploration Agency (JAXA) DAICHI (ALOS) satellite. The data on this explosive rhyolite eruption indicate that the rapid ascent of rhyolite occurred through dyking and that melt segregation and magma storage were controlled by existing faults.

Wicks, C.; De La, Llera, J. C.; Lara, L.E.; Lowenstern, J.

2011-01-01

35

Clastic dikes of Heart Mountain fault breccia, northwestern Wyoming, and their significance  

USGS Publications Warehouse

Structural features in northwestern Wyoming indicate that the Heart Mountain fault movement was an extremely rapid, cataclysmic event that created a large volume of carbonate fault breccia derived entirely from the lower part of the upper plate. After fault movement had ceased, much of the carbonate fault breccia, here called calcibreccia, lay loose on the resulting surface of tectonic denudation. Before this unconsolidated calcibreccia could be removed by erosion, it was buried beneath a cover of Tertiary volcanic rocks: the Wapiti Formation, composed of volcanic breccia, poorly sorted volcanic breccia mudflows, and lava flows, and clearly shown in many places by inter lensing and intermixing of the calcibreccia with basal volcanic rocks. As the weight of volcanic overburden increased, the unstable water-saturated calcibreccia became mobile and semifluid and was injected upward as dikes into the overlying volcanic rocks and to a lesser extent into rocks of the upper plate. In some places the lowermost part of the volcanic overburden appears to have flowed with the calcibreccia to form dike like bodies of mixed volcanic rock and calcibreccia. One calcibreccia dike even contains carbonized wood, presumably incorporated into unconsolidated calcibreccia on the surface of tectonic denudation and covered by volcanic rocks before moving upward with the dike. Angular xenoliths of Precambrian rocks, enclosed in another calcibreccia dike and in an adjoining dikelike mass of volcanic rock as well, are believed to have been torn from the walls of a vent and incorporated into the basal part of the Wapiti Formation overlying the clastic carbonate rock on the fault surface. Subsequently, some of these xenoliths were incorporated into the calcibreccia during the process of dike intrusion. Throughout the Heart Mountain fault area, the basal part of the upper-plate blocks or masses are brecciated, irrespective of the size of the blocks, more intensely at the base and in places extending upward for several tens of meters. North of Republic Mountain a small 25-m-high upper-plate mass, brecciated to some degree throughout, apparently moved some distance along the Heart Mountain fault as brecciated rock. Calcibreccia dikes intrude upward from the underlying 2 m of fault breccia into the lower part of the mass and also from its top into the overlying volcanic rocks; an earthquake-related mechanism most likely accounts for the observed features of this deformed body. Calcibreccia dikes are more common within the bedding-plane phase of the Heart Mountain fault but also occur in its transgressive and former land-surface phases. Evidence that the Wapiti Formation almost immediately buried loose, unconsolidated fault breccia that was the source of the dike rock strongly suggests a rapid volcanic deposition over the area in which clastic dikes occur, which is at least 75 km long. Clastic dikes were injected into both the upper-plate and the volcanic rocks at about the same time, after movement on the Heart Mouuntain fault had ceased, and therefore do not indicate a fluid-flotation mechanism for the Heart Mountain fault. The difference between contacts of the clastic dikes with both indurated and unconsolidated country rock is useful in field mapping at localities where it is difficult to distinguish between volcanic rocks of the Cathedral Cliffs and Lamar River Formations, and the Wapiti Formation. Thus, calcibreccia dikes in the Cathedral Cliffs and Lamar River Formations show a sharp contact because the country rock solidified prior to fault movement, whereas calcibreccia dikes in the Wapiti Formation in many instances show a transitional or semifluid contact because the country rock was still unconsolidated or semifluid at the time of dike injection.

Pierce, W. G.

1979-01-01

36

In situ investigations of vault paintings in the Antwerp cathedral.  

PubMed

X-ray fluorescence spectroscopy (XRF) and Raman spectroscopy have been used to examine 15th century mediaeval and 16th century renaissance vault paintings in the Our Lady's Cathedral (Antwerp, Belgium) in view of their restoration. The use of mobile instruments made it possible to work totally non-destructively. This complementary approach yields information on the elemental (XRF) and on the molecular composition (Raman) of the pigments. For the 15th century vault painting the pigments lead-tin yellow (Pb(2)SnO(4)), lead white (2PbCO(3)xPb(OH)(2)), vermilion (HgS), massicot (PbO) and azurite (2CuCO(3).Cu(OH)(2)) could be identified. The pigments used for the 16th century vault painting could be identified as red lead (Pb(3)O(4)), hematite (Fe(2)O(3)), lead white (2PbCO(3)xPb(OH)(2)) and azurite (2CuCO(3)xCu(OH)(2)). For both paintings the presence of the strong Raman scatterer calcite (CaCO(3)) resulted in a difficult identification of the pigments by Raman spectroscopy. The presence of gypsum (CaSO(4)x2H(2)O) on the mediaeval vault painting probably indicates that degradation took place. PMID:20036616

Deneckere, Annelien; Schudel, Walter; Van Bos, Marina; Wouters, Helena; Bergmans, Anna; Vandenabeele, Peter; Moens, Luc

2010-02-01

37

Rapid Slip-Rate and Low Shear Strength of a High Finite-Slip Low-Angle Normal Fault: Normanby Island, Woodlark Rift, Papua New Guinea  

NASA Astrophysics Data System (ADS)

A metamorphic core complex (MCC) punctuates the attenuated continental crust of Normanby Island in the D'Entrecasteaux Group of SE Papua New Guinea, 30 km west of the seafloor- spreading tip of the Woodlark Basin. The lower plate of this north-vergent MCC has been uplifted by as much as ~1100 m above sealevel and exposes a >1 km thick carapace of blueschist-derived quartzose mylonites that have a subhorizontal top-to-the-NNE shear fabric. Onshore, the variably back-tilted, inactive detachment fault capping these mylonites has been eroded away, but its corrugated geomorphology is preserved in the landscape of the asymmetric dome. Corrugations and stretching lineations parallel solutions for Woodlark- Australia plate motions from 3.6-0.52 Ma. North of the island, the detachment fault is preserved as a ~12° N-dipping scarp on the seafloor. The northern, submarine part of the Woodlark rift contains several active half-grabens, and has been the site of several >Mw 6.0 earthquakes on planes dipping 23-30° N. Focal depths in this part of the rift are <8-9 km (Abers {it et al.,} 1997). The ~40-km exhumed length of the fault, and estimates of the temperature and minimum depth (8-10 km) of mylonitization imply a finite dip-slip of at least 50 km. ODP stratigraphic data from nearby Moresby Seamount suggest that slip on the Normanby fault had begun by ~3.8 Ma. 40Ar/39Ar data from the lower plate have yielded plateau ages on mylonitic white mica of 3-4 Ma, interpreted as cooling ages. A preliminary estimate of the age gradient parallel to transport suggests a minimum slip-rate of ~24 ±5mm/yr (assumes a geotherm at dynamic equilibrium) on this rolling hinge-style MCC, one of the fastest slip-rates ever determined for a normal fault. This is ~70% of the rift's spreading rate during that interval, implying marked strain localization on a single, highly evolved low-angle normal fault. MCC's in the Woodlark Rift are bounded transversely by continental transform faults that juxtapose them against wider rheologic domains containing more uniform-strength normal faults of smaller offset. The rapidly exhumed mylonites are ideal candidates for recrystallised grain-size paleopiezometry on quartz. The calibration of Stipp and Tullis (2003) was applied to 7 samples to obtain flow stress estimates of 27 ±7 MPa (1?). We infer that these record differential stress at the time of quenching-in of the fabrics, when they were overprinted by extension gashes near the brittle-ductile transition. For assumed depths of >8 km, these observations require pore fluid pressure ratios >0.85. Prolonged, rapid slip on the Normanby Island fault at low dip was thus assisted by high fluid pressure, perhaps in response to the discharge of hot metamorphic fluids at depth. Because the detachment fault is inferred to reactivate the base of the Papuan ultramafic body, talc-serpentine gouge may also have contributed an intrinsic frictional weakness to this low-angle fault.

Little, T. A.; Monteleone, B.; Baldwin, S. L.; Fitzgerald, P. G.

2006-12-01

38

Stress analysis of the piers of the Tarazona Cathedral (Zaragoza – Spain) by means of the hole-drilling technique  

Microsoft Academic Search

The paper deals with the application of the hole-drilling technique on the four piers of the crossing under the dome of the Cathedral of Tarazona (Zaragoza – Spain). The hole-drilling technique in architectural heritage is named the Donostia Method by the author in previous works. The monument (XIIIth Century) is an excellent cathedral not well known because 25 years ago

Santiago Sánchez Beitia

2008-01-01

39

Evidence for rapid displacement on Himalayan normal faults and the importance of tectonic denudation in the evolution of mountain ranges  

NASA Astrophysics Data System (ADS)

East-striking, low-angle normal faults of the South Tibetan detachment system have played an important role in exposing the high-grade metamorphic core of the Himalayan orogen. In the Mount Everest region of southern Tibet, granites both pre- and postdate an important fault of the system, the Qomolangma detachment. New U-Pb and 40Ar/39Ar geochronologic data for these rocks constrain the age of brittle faulting to between 16.67 ± 0.04 and 16.37 ± 0.40 Ma, significantly expanding the known age range for extension in the central Himalaya (widely regarded as ca. 20 22 Ma). More importantly, they indicate an average displacement rate of ?47 mm/yr and a consequent tectonic unroofing rate of ?8.2 mm/yr. Such unroofing is faster than all but the highest estimates of combined physical and chemical erosion rates in mountainous regions, suggesting that large-displacement normal faulting can be an extremely efficient agent of mass redistribution in orogenic systems.

Hodges, Kip; Bowring, Samuel; Davidek, Kathleen; Hawkins, David; Krol, Michael

1998-06-01

40

GPR and sonic tomography for structural restoration: the case of the cathedral of Tricarico  

Microsoft Academic Search

In this paper, we present the results of a diagnostics survey, based on the exploitation of ground penetrating radar (GPR) and sonic prospecting, to characterize the deterioration status of the pillars of the cathedral of Tricarico, in the Basilicata region (Southern Italy). The prospecting falls within the more general framework of investigating the structural conditions of this monument, which is

G. Leucci; N. Masini; R. Persico; F. Soldovieri

2011-01-01

41

The economic legacy of gothic cathedral building: France and England compared  

Microsoft Academic Search

The accomplishments of the Gothic cathedral builders are immense. They are usually examined in terms of technical and artistic achievement, however, This seems shortsighted in view of their economic ramifications. The legacy of these works can be seen in technology, specialization and mobility of labor, and procedures in accounting. They thus served as a vehicle for the transformation of feudal

Virginia Lee Owen

1989-01-01

42

The glasses of the transept's rosette of the cathedral of Tarragona: characterisation, classification and decay  

Microsoft Academic Search

The glasses of the rosette forming the main window of the transept of the Gothic Cathedral of Tarragona have been characterised by means of SEM\\/EDS, XRD, FTIR and electronic microprobe. The multivariate statistical treatment of these data allow to establish a classification of the samples forming groups having an historical significance and reflecting ancient restorations. Furthermore, the decay patterns and

M. GARCIA-VALLÈS; M. VENDRELL-SAZ

43

INTEGRATED 3D-DATABASE FOR DIAGNOSTICS AND DOCUMENTATION OF MILAN'S CATHEDRAL FAÇADE  

Microsoft Academic Search

The Gothic Cathedral of Milan is one of the most important italian monuments: its façade is 65 m high with 12 spires and has a surface of about 4500 m2, rich of Candoglia marble carved decorations and sculptures. The conservative restoration and maintenance of so complex an architectural structure needs advanced computerized tools for storing, analysing and updating all the

E. Giunta; L. Menci; Veneranda Fabbrica del Duomo

44

Geomechanics of Large Stone Structures: A Case History from the Washington National Cathedral  

Microsoft Academic Search

The Washington National Cathedral is one of the largest masonry structures in the USA, and like many of its European Gothic counterparts, it required nearly a century to construct. The design was altered during this period, resulting in greater loadings than were originally anticipated on the soil beneath the foundation. When signs of continuing differential settlement were observed in the

R. Mark; R. Richards

45

Innovative 3D information system for the restoration and preventive maintenance plan of the Milan Cathedral  

Microsoft Academic Search

The restoration and maintenance of architecturally complex monuments need advanced tools for helping the definition of the working plan and for storing analysing and updating all the data produced. In the case of the Gothic Milan Cathedral a three-dimensional metric support has been developed. It comprises several oriented and connected stereoscopic models which makes it possible, through the stereoscopic vision,

Giuseppe G. Giunta; Eleonora Di Paola; Benigno Morlin Visconti Castiglione

2004-01-01

46

"ch01" --2009/7/4 --4:33 --page 3 --#3 Thermo-and hydro-mechanical processes along faults during rapid slip  

E-print Network

of maturely slipped faults show a generally broad zone of damage by cracking and granulation. Nevertheless, large shear deformation, and therefore heat generation, in individual earthquakes takes place with extreme localization to a zone granulated fault core. Relevant fault

47

The effect of air pollution on the stone decay of the Cologne Cathedral  

NASA Astrophysics Data System (ADS)

Different building stones of the Cologne Cathedral show a large variation of weathering phenomena. The Drachenfels trachyte, which was the construction material for the medieval part of the cathedral, shows significant surface deterioration, back-weathering coexisting with flaking, crumbling or the massive formation of gypsum crusts. Wolff (1992) first mentioned the negative interferences between the Schlaitdorfer sandstone and the Londorfer basalt lava or the Drachenfels trachyte and the Krensheimer muschelkalk. Crust formation on limestone, sandstone, and volcanic rock from the Cologne Cathedral as well as from the Xanten and Altenberg Cathedral are investigated. These three buildings are located in different areas and exposed to varying industrial, urban, and rural environmental situations. The material investigated range from dark grey to black framboidal crusts. This 3 to 10 mm thick cauliflower-like form of gypsum crust incorporates particles from the pollution fluxes. It covers the stone surface and mainly occurs at sites protected from wind and direct rain. Secondly, thin laminar black crusts trace the stone surface and may cover complete sections of the building's structure not necessarily preferring protected sites. This kind of crust seems to have very strong bonds between the thin black crust and the stone surface. Major and trace element distribution show an enrichment of sulfur, indicating the presence of gypsum, lead and other typical pollutants (arsenic, antimony, bismuth, tin etc.), which generally can be linked to traffic and industry. This indicates that even though the SO2 emission has decreased due to i.e. stronger regulations of waste incineration plants and the ban of leaded petrol, the pollutants are still present in the crusts on the building stones. From systematic SEM observations it becomes evident that the total amount of pollution is less pronounced in the Altenberg and Xanten Cathedrals as compared with the Cologne Cathedral. The formation of gypsum occurs at lower amounts in Altenberg, which correlates well with the measured SO2 content. On the other hand, the increasing H2O content in the trachyte and the crusts correlates well with an increasing phyllosilicate formation. Through the combination of different analytical techniques it was possible to clearly distinguish samples from the industrial or rural environment. If the data is compared to actual pollutant emissions, the analyzed samples imply present but also past pollution fluxes. Thus, the soiled zones of the built environment can function as environmental indicators.

Graue, B.; Siegesmund, S.; Licha, T.; Simon, K.; Oyhantcabal, P.; Middendorf, B.

2012-04-01

48

Rapid estimation of fault parameters for tsunami warning along the Mexican subduction zone based on real-time GPS (Invited)  

NASA Astrophysics Data System (ADS)

A reliable and robust tsunami early warning is now possible thanks to the availability of real-time GPS data. With few assumptions regarding the characteristics of the geometry of the subduction interface (dip, width of the seismogenic zone, and maximum depth of the seismically-coupled interface), we can estimate the length, L, and the width, W, of the rupture, as well as its downdip extension, C (Singh et al., 2008; 2012). These are estimated from the amplitude of the observed horizontal displacement along the coast and its fall off with distance, as well as the polarity of the vertical displacement. Based on Okada's (1992) model, we compute the slip D on the fault, to finally obtain the seismic moment, Mo. Pérez-Campos et al. (2013) showed the feasibility of such tsunami early warning for the Mexican subduction zone. Mo could be obtained in ~2 min after origin time from a dense distribution of real-time high-rate GPS stations along the coast. However, the current GPS network is sparse. Despite this, a robust estimate of magnitude Mw can be obtained. For this work, we perform sensitivity tests for Mw and position of the fault with respect to the trench.

Perez-Campos, X.; Singh, S. K.; Melgar, D.; Cruz Atienza, V. M.; Iglesias, A.; Hjorleifsdottir, V.

2013-12-01

49

Study of glasses with grisailles from historic stained glass windows of the cathedral of León (Spain)  

NASA Astrophysics Data System (ADS)

This work concerns the study of grisailles of historic glass samples from stained glass windows of the Cathedral of León, which were removed during the restoration carried out in 19th century. Both the glass samples and their coloured grisailles showed very different chemical composition and macroscopic heterogeneity. As a general rule their deterioration degree is rather moderate, maybe due to the pieces removal that preserve them from the high atmospheric pollution occurred in the last century. The present research pointed out the physical characteristics, chemical compositions and deterioration degree of the samples selected from the most important Spanish ensemble of Medieval and Renaissance stained glass windows. Moreover, this work offers sufficient results to be compared with those formerly obtained for other stained glass windows from European cathedrals and churches.

Carmona, N.; Villegas, M. A.; Navarro, J. M. Fernández

2006-06-01

50

The Façade and the Rose-Window of Troia Cathedral (Apulia, Italy)  

Microsoft Academic Search

The façade of Troia Cathedral is tilted around a horizontal hinge, of seismic o r i- gin and passing through the rose-window. As a consequence, the rose-window is heavily dam- aged and deformed out-of-plane. In this paper, cognitive and diagnostic investigations are pre- sented on the materials and the elements of the rose-window (GPR, thermography, sonic and ultrasonic tests, ambient

Domenico Liberatore; Giuseppe Spera; Marco Mucciarelli; Nicola Masini; Angela Calia; Alessandro Capriuoli; Vito Racina; Luigia Nuzzo; Luigia Binda; Lorenzo Cantini

51

A Speculation on an Affinity between Ruskin's Seven Lamps of Architecture and Monet's Cathedrals  

Microsoft Academic Search

Discusses John Ruskin’s architectural aesthetics and his view of the Gothic style as expressed in his Seven Lamps of Architecture. Discovers similarities between Ruskin’s ideas and the ideas and methods of Claude Monet, evident in his series of paintings of Rouen Cathedral, 1892-1895. Describes how Ruskin’s theories grew out of and advanced beyond the aesthetics of the Gothic revival movement,

Elizabeth C Teviotdale

1983-01-01

52

Innovative 3D information system for the restoration and preventive maintenance plan of the Milan Cathedral  

NASA Astrophysics Data System (ADS)

The restoration and maintenance of architecturally complex monuments need advanced tools for helping the definition of the working plan and for storing analysing and updating all the data produced. In the case of the Gothic Milan Cathedral a three-dimensional metric support has been developed. It comprises several oriented and connected stereoscopic models which makes it possible, through the stereoscopic vision, to navigate through several photograms, to accurately measure the dimension of architectural details, to draw structures with a millimeter precision. In this way a 3D-CAD model of the facade and of the internal walls of the Milan Cathedral have been created. On those vectorial models, it is possible to insert photos, documents, characterisation data and even to draw thematic maps. For instance, the load bearing structures maps have been realised after a GPR (Ground Penetrating Radar) structural survey. These maps provide structural information (e.g. fractures, block thickness and status, lessons, etc.) extremely useful for planning the restoration and maintenance work. The photogrammetric survey has been proceeded by a 3D laser scanning survey, necessary for providing a preliminary model for planning the work until the complete elaboration of the stereoscopic model. All the data have been updated in the georeferenced and integrated 3D data base of the Cathedral, which now constitutes the necessary support for defining the specific operations.

Giunta, Giuseppe G.; Di Paola, Eleonora; Morlin Visconti Castiglione, Benigno

2004-02-01

53

Exeter Cathedral Keystones and Carvings: A Catalogue Raisonne of the Sculptures & Their Polychromy  

NSDL National Science Digital Library

Exeter Cathedral Keystones and Carvings functions as "an illustrated introduction to, and explanatory catalogue of all the figurative sculpture that is part of the original interior fabric of the medieval building." The material on the site, which is primarily geared toward art historians and medievalists, was compiled by Avril Kay Henry, former professor of English Medieval Culture at University of Exeter, and the late Anna Carson Hulbert, a well known conservator. The site does not provide a tour through the cathedral so much as it offers photos and explanations of the individual sculptural pieces: "medieval bosses, corbels, labelstops, figurative capitals (and a few other interior carvings) which are an integral part of the medieval interior construction of Exeter Cathedral, Devon, England." Users can browse or search the contents, and a nice introduction and bibliography are both useful supplements. From the homepage, users can access a page that explains navigation and layout of the site, entitled The Resource: Coverage and Use. This one is well worth a stop for medievalists.

Henry, Avril.; Hulbert, Anna C.

2001-01-01

54

Listener perception of and acoustic differences between girl and boy choristers in an English cathedral choir  

NASA Astrophysics Data System (ADS)

For centuries, boy choristers have been singing the top (treble) line in English cathedrals. Girl choristers were first admitted in 1991, and there is a long-running debate as to whether they can carry out this role appropriately. This paper will detail the results from two listening experiments designed to establish whether or not listeners can tell the difference between girl and boy choristers singing the top line in cathedral music. In the first experiment, 189 listeners took part and on average they were able to tell the difference 60% of the time; this was statistically significant over chance. The results suggested that repertoire played a significant part in this ability, and the second experiment was carried out in which the boys and girls sang the same repertoire. Nearly 170 listeners have completed this experiment and, on average, they are making guesses (correct 52% of the time). The paper will discuss the acoustic differences between the stimuli with respect to the singing of boy and girl choristers, while placing the discussion in the context of the English cathedral tradition.

Howard, David; Welch, Graham

2005-09-01

55

Integration of constrained electrical and seismic tomographies to study the landslide affecting the cathedral of Agrigento  

NASA Astrophysics Data System (ADS)

The Cathedral of Saint Gerland, located on the top of the hill of Agrigento, is an important historical church, which dates back to the Arab–Norman period (XI century). Unfortunately throughout its history the Cathedral and the adjacent famous Archaeological Park of the ‘Valley of the Temples’ have been affected by landslides. In this area the interleaving of calcarenites, silt, sand and clay is complicated by the presence of dislocated rock blocks and cavities and by a system of fractures partly filled with clay or water. Integrated geophysical surveys were carried out on the north side of the hill, on which the Cathedral of Agrigento is founded, to define lithological structures involved in the failure process. Because of the landslide, the cathedral has been affected by fractures, which resulted in the overall instability of the structure. Along each of four footpaths a combination of 2D electrical resistivity tomographies (ERT) and 2D seismic refraction tomographies (SRT) was performed. Moreover, along two of these footpaths microtremor (HVSR) and surface wave soundings (MASW) were carried out to reconstruct 2D sections of shear waves velocity. Furthermore a 3D electrical resistivity tomography was carried out in a limited area characterized by gentle slopes. After a preliminary phase, in which the data were processed independently, a subsequent inversion of seismic and electrical data was constrained with stratigraphic information obtained from geognostic continuous core boreholes located along the geophysical lines. This process allowed us to significantly increase the robustness of the geophysical models. The acquired data were interpolated to construct 3D geophysical models of the electrical resistivity and of the P-wave velocity. The interpolation algorithm took into account the average direction and immersion of geological strata. Results led to a better understanding of the complexity of the subsoil in the investigated area. The use of integrated geophysical techniques allowed us to understand the sliding processes that affect the slope delimiting the possible rock volume affected by the sliding. These results should be useful to define the works to consolidate the landslides affecting the slope on which the Cathedral is founded and the hill inside the Archaeological Park.

Capizzi, P.; Martorana, R.

2014-08-01

56

The South Fork detachment fault, Park County, Wyoming: discussion and reply ( USA).  

USGS Publications Warehouse

Blackstone (1985) published an interpretation of South form detachment fault and related features. His interpretation of the area between Castle and Hardpan transverse faults is identical to mine of 1941. Subsequent detailed mapping has shown that the structure between the transverse faults is more complicated than originally envisioned and resurrected by Blackstone. The present paper describes and discusses geologic features that are the basis for my interpretations; also discussed are differences between my interpretations and those of Blackstone. Most data are shown on the geologic map of the Wapiti Quadrangle (Pierce and Nelson, 1969). Blackstone's 'allochthonous' masses are part of the South Form fault. Occurrences of Sundance Formation, which he interpreted as the upper plate of his 'North Fork fault', are related to Heart Mountain fault. Volcaniclastic rocks south of Jim Mountain mapped as Aycross Formation by Torres and Gingerich may be Cathedral Cliffs Formation, emplaced by movement of the Heart Mountain fault. - Author

Pierce, W.G.

1986-01-01

57

The transmission of masticatory forces and nasal septum: structural comparison of the human skull and Gothic cathedral.  

PubMed

This study extrapolates the transmission of masticatory forces to the cranium based on the architectural principles of Gothic cathedrals. The most significant finding of the study, obtained by analysis of coronal CT scans, is the role of the hard palate, and especially the vomer and the perpendicular plate of the ethmoid in masticatory force transmission. The study also confirms, experimentally, the paths of masticatory forces, cited in literature but based purely on morphological observations. Human skulls and Gothic cathedrals have similar morphological and functional characteristics. The load exerted by the roof of the cathedral is transmitted to the ground by piers and buttresses. These structures also resist the shearing forces exerted by high winds. Similarly, the mid-facial bones of the skull transmit the vertical as well as the lateral masticatory forces from the maxillary dentition to the skull base. The nonload bearing walls and stained glass windows of the cathedral correspond to the translucent wall of the maxilla. The passageway between the aisle and the nave of the cathedral is equivalent to the meatal openings in the lateral wall of the nasal cavity. PMID:17696032

Hilloowala, Rumy; Kanth, Hrishi

2007-07-01

58

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.

59

Polyphase exhumation in the western Qinling Mountains, China: Rapid Early Cretaceous cooling along a lithospheric-scale tear fault and pulsed Cenozoic uplift  

NASA Astrophysics Data System (ADS)

The western sector of the Qinling-Dabie orogenic belt plays a key role in both Late Jurassic to Early Cretaceous "Yanshanian" intracontinental tectonics and Cenozoic lateral escape triggered by India-Asia collision. The Taibai granite in the northern Qinling Mountains is located at the westernmost tip of a Yanshanian granite belt. It consists of multiple intrusions, constrained by new Late Jurassic and Early Cretaceous U-Pb zircon ages (156 ± 3 Ma and 124 ± 1 Ma). Applying various geochronometers (40Ar/39Ar on hornblende, biotite and K-feldspar, apatite fission-track, apatite [U-Th-Sm]/He) along a vertical profile of the Taibai Mountain refines the cooling and exhumation history. The new age constraints record the prolonged pre-Cenozoic intracontinental deformation as well as the cooling history mostly related to India-Asia collision. We detected rapid cooling for the Taibai granite from ca. 800 to 100 °C during Early Cretaceous (ca. 123 to 100 Ma) followed by a period of slow cooling from ca. 100 Ma to ca. 25 Ma, and pulsed exhumation of the low-relief Cretaceous peneplain during Cenozoic times. We interpret the Early Cretaceous rapid cooling and exhumation as a result from activity along the southern sinistral lithospheric scale tear fault of the recently postulated intracontinental subduction of the Archean/Palaeoproterozoic North China Block beneath the Alashan Block. A Late Oligocene to Early Miocene cooling phase might be triggered either by the lateral motion during India-Asia collision and/or the Pacific subduction zone. Late Miocene intensified cooling is ascribed to uplift of the Tibetan Plateau.

Heberer, Bianca; Anzenbacher, Thomas; Neubauer, Franz; Genser, Johann; Dong, Yunpeng; Dunkl, István

2014-03-01

60

Observation on the recent examination of bones from St David's Cathedral.  

PubMed

Bones discovered in 1866 walled up in St David's Cathedral, West Wales were thought possibly to be those of St David and his companion St Justinian, both of whom died in the late 6th or early 7th century. Examination and radio carbon dating of the bones suggested that these were not from St David nor St Justinian. Some of the bones could be the remains of St Caradoc, a 12th century hermit. It is likely, however, that the bones are remains of clergy who, for reasons not yet understood, were re-interred into the wall. PMID:10689864

Nokes, L D; Evans, W; Knight, B H; Dent, C

2000-01-01

61

The marble frieze patterns of the cathedral of Siena: geometric structure, multi-stable perception and types of repetition  

Microsoft Academic Search

The marble pavement of the Cathedral in the Tuscan city of Siena in Italy has been described as one of the marvels of the world. Over the centuries much has been written about its biblical and political characters, the stories depicted in its figurative mosaics, the artists responsible for creating the mosaics, the types of marble used and the history

Yang Liu; Godfried T. Toussaint

2011-01-01

62

A review of the book: "Turing's Cathedral: The origins of the digital universe", George Dyson (Pantheon Books, 2012).  

E-print Network

A review of the book: "Turing's Cathedral: The origins of the digital universe", George Dyson (Pantheon Books, 2012). Josep D�iaz. LSI, UPC. (diaz@lsi.upc.edu) 1. Introduction The title of this book is very appropriated for the year 2012, the centenary of the birth of Alan Turing. The gist of the book

Diaz, Josep

63

A multifrequency and multisensor approach for the study and the restoration of monuments: the case of the Cathedral of Matera  

Microsoft Academic Search

In this paper we propose an integrated approach to diagnostic prospecting applied to the cathedral of Matera, in Southern Italy. In particular, we have performed both an ultrasonic tomography and a high frequency GPR prospecting on some pillars of the Church to investigate about possible structural yielding and a GPR prospecting at lower frequencies on the floor, where also a

N. Masini; R. Persico; A. Guida; A. Pagliuca

2008-01-01

64

Arvicoline rodent fauna from the Room 2 Excavation in Cathedral Cave, White Pine County, Nevada, and its biochronologic significance  

Microsoft Academic Search

Test-pit excavations from 1989 in Room 2 of Cathedral Cave yielded a diverse faunal assemblage, but age estimates derived from radioisotopic dates and biochronological assessment were widely disparate. New excavations were undertaken in 2003 to increase faunal samples and clarify chronological resolution. Arvicoline rodents recovered from the 2003 excavation include Allophaiomys pliocaenicus, Microtus meadensis, M. paroperarius, Microtus sp., Mictomys meltoni

Christopher N. Jass; Christopher J. Bell

2011-01-01

65

Examples of weathering and deterioration of Tertiary building stones at St. Michaels Cathedral in Cluj-Napoca (Romania)  

Microsoft Academic Search

St. Michaels Cathedral is one of the oldest Gothic architectural monuments in Cluj. It is built predominantly of Cenozoic (Eocene) limestones which were deposited on a shallow carbonate platform. They are composed of different facies and microfacies types with varying amounts of particles, matrix and cement. Limestones from the Baci quarry (Cluj Limestone), which is situated about 3 km from

Roman Koch; Paul Calin Racataianu; Ioan I. Bucur

2008-01-01

66

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

67

Faulted Barn  

USGS Multimedia Gallery

This barn is faulted through the middle; the moletrack is seen in the foreground with the viewer standing on the fault. From the air one can see metal roof panels of the barn that rotated as the barn was faulted....

2009-01-22

68

SIMULTANEOUS FAULT DETECTION AND CLASSIFICATION FOR SEMICONDUCTOR MANUFACTURING TOOLS  

E-print Network

SIMULTANEOUS FAULT DETECTION AND CLASSIFICATION FOR SEMICONDUCTOR MANUFACTURING TOOLS Brian E, accurate, and sensitive detection of equipment and process faults to maintain high process yields and rapid fault classification (diagnosis) of the cause to minimize tool downtime in semiconductor manufacturing

Boning, Duane S.

69

Photogrammetric and LIDAR Documentation of the Royal Chapel Cathedral-Mosque of Cordoba, Spain)  

NASA Astrophysics Data System (ADS)

At present, cultural heritage documentation projects use a variety of spatial data acquisition techniques such as conventional surveying, photogrammetry and terrestrial laser scanning. This paper deals with a full documentation project based on all those techniques in the Royal Chapel located in the Cathedral-Mosque of Cordoba in Spain, declared World Heritage Site by UNESCO. At present, the Royal Chapel is under study for a detailed diagnostic analysis in order to evaluate the actual state of the chapel, pathologies, construction phases, previous restoration works, material analysis, etc. So in order to assist the evaluation, a documentation project with photogrammetric and laser scanner techniques (TLS) has been carried out. With this purpose, accurate cartographic and 3D products, by means of the integration of both image and laser based techniques, were needed to register all data collected during the diagnostic analysis.

Cardenal, J.; Perez-Garcia, J. L.; Mata, E.; Hernandez, M. A.; Mozas, A.; Delgado, J.; Lopez-Arenas, A.; Meroño, J. E.

2012-07-01

70

Fault finder  

DOEpatents

A fault finder for locating faults along a high voltage electrical transmission line. Real time monitoring of background noise and improved filtering of input signals is used to identify the occurrence of a fault. A fault is detected at both a master and remote unit spaced along the line. A master clock synchronizes operation of a similar clock at the remote unit. Both units include modulator and demodulator circuits for transmission of clock signals and data. All data is received at the master unit for processing to determine an accurate fault distance calculation.

Bunch, Richard H. (1614 NW. 106th St., Vancouver, WA 98665)

1986-01-01

71

Spectrometric investigation of the weathering process affecting historical glasses of León Cathedral, Spain  

NASA Astrophysics Data System (ADS)

Atmospheric pollution plays important roles in the weathering of the historical buildings and glass windows. Samples of white powdered weathering products, recovered during restoration of the stained-glass windows of León Cathedral in Spain, were characterised using a combination of scanning electron microscopy (SEM) with energy dispersive-X ray spectrometry (ED-XRS), Fourier transform-infrared (FT-IR) spectroscopy and Raman spectrometry. The presence of sulphates, and to a lesser extent carbonates, in the white powdered product is clear indication of the participation of atmospheric acidifying gases, particularly SOx, in the weathering process. It is interesting to note that there was no indication of the participation of NOx gases. There was, however, evidence that the putty and mortar used to seal/join the glasses were major sources of the weathering products. In this way, this study suggests sealants more resistant to oxidation, such as silicone- and zirconia-based materials, should be considered for repairing glass windows in historic buildings to avoid exacerbating degradation.

Castro, M. A.; Pereira, F. J.; Aller, A. J.; Littlejohn, D.

2014-12-01

72

An in situ corrosion study of Middle Ages wrought iron bar chains in the Amiens Cathedral  

NASA Astrophysics Data System (ADS)

The corrosion behaviour of Middle Ages wrought iron bar chains exposed to indoor atmospheric corrosion for hundred of years in the Notre Dame Cathedral of Amiens (France) has been evaluated by means of Electrochemical Impedance Spectroscopy (EIS), a well-established electrochemical technique extensively used for testing anticorrosive properties of metal coatings. The measurements have been performed in situ with a portable EIS instrument designed to work as a standalone device, in six different areas of the wrought iron bar chains characterized by different aesthetical appearance. Moreover, a properly designed electrochemical cell has been employed to carry out the impedance measurements without affecting the artefacts surfaces. The wrought iron bar chains, as evidenced by ?-Raman and microscopic analyses, are covered by corrosion products constituted by iron oxides and oxyhydroxides, such as goethite, lepidocrocite, maghemite, akaganeite, organized in complex layered structures. In situ EIS allows one to investigate the phenomena involved at the electrochemical interfaces among the various corrosion products and to assess and predict their corrosion behaviour. From the analysis of the experimental findings of this monitoring campaign, EIS measurements can be proposed to restorers/conservators as a reliable indicator of dangerous situations on which they must act for the preservation of the iron artefacts.

Grassini, S.; Angelini, E.; Parvis, M.; Bouchar, M.; Dillmann, P.; Neff, D.

2013-12-01

73

Fault-zone healing effectiveness and the structural evolution of strike-slip fault systems  

NASA Astrophysics Data System (ADS)

Numerical simulations of long-term crustal deformation reveal the important role that damage healing (i.e. fault-zone strengthening) plays in the structural evolution of strike-slip fault systems. We explore the sensitivity of simulated fault zone structure and evolution patterns to reasonable variations in the healing-rate parameters in a continuum damage rheology model. Healing effectiveness, defined herein as a function of the healing rate parameters, describes the post-seismic healing process in terms of the characteristic inter-seismic damage level expected along fault segments in our simulations. Healing effectiveness is shown to control the spatial extent of damage zones and the long-term geometrical complexity of strike-slip fault systems in our 3-D simulations. Specifically, simulations with highly effective healing form interseismically shallow fault cores bracketed by wide zones of off-fault damage. Ineffective healing yields deeper fault cores that persist throughout the interseismic interval, and narrower zones of off-fault damage. Furthermore, highly effective healing leads to a rapid evolution of an initially segmented fault system to a simpler through-going fault, while ineffective healing along a segmented fault preserves complexities such as stepovers and fault jogs. Healing effectiveness and its role in fault evolution in our model may be generalized to describe how heat, fluid-flow and stress conditions (that contribute to fault-zone healing) affect fault-zone structure and fault system evolution patterns.

Finzi, Yaron; Hearn, Elizabeth H.; Lyakhovsky, Vladimir; Gross, Lutz

2011-09-01

74

Simultaneous Fault Detection and Classification for Semiconductor Manufacturing Tools  

E-print Network

Simultaneous Fault Detection and Classification for Semiconductor Manufacturing Tools Brian E detection of equipment and process faults to maintain high process yields and rapid fault classification treat fault detection and classification as a two-step process. We present a novel method

Boning, Duane S.

75

Typology of the granitic stones of the cathedral of Évora (Portugal): a combined contribution of geochemistry and 57Fe Mössbauer spectroscopy  

Microsoft Academic Search

A geochemical study, including a detailed investigation of Fe by Mössbauer spectroscopy, was undertaken to characterise the different varieties of the stones in the cathedral of Évora (Portugal). Ten representative stone samples were collected. Bulk analytical techniques, including ICPES, INAA and XRF, were performed, as well as Mössbauer spectroscopy. The stones have consistent linear geochemical variations, well constrained by a

Mohamed Nasraoui; João C Waerenborgh; Maria I Prudêncio; Essaid Bilal

2002-01-01

76

Fault mechanics  

SciTech Connect

Recent observational, experimental, and theoretical modeling studies of fault mechanics are discussed in a critical review of U.S. research from the period 1987-1990. Topics examined include interseismic strain accumulation, coseismic deformation, postseismic deformation, and the earthquake cycle; long-term deformation; fault friction and the instability mechanism; pore pressure and normal stress effects; instability models; strain measurements prior to earthquakes; stochastic modeling of earthquakes; and deep-focus earthquakes. Maps, graphs, and a comprehensive bibliography are provided. 220 refs.

Segall, P. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

77

Rule-based fault diagnosis of hall sensors and fault-tolerant control of PMSM  

NASA Astrophysics Data System (ADS)

Hall sensor is widely used for estimating rotor phase of permanent magnet synchronous motor(PMSM). And rotor position is an essential parameter of PMSM control algorithm, hence it is very dangerous if Hall senor faults occur. But there is scarcely any research focusing on fault diagnosis and fault-tolerant control of Hall sensor used in PMSM. From this standpoint, the Hall sensor faults which may occur during the PMSM operating are theoretically analyzed. According to the analysis results, the fault diagnosis algorithm of Hall sensor, which is based on three rules, is proposed to classify the fault phenomena accurately. The rotor phase estimation algorithms, based on one or two Hall sensor(s), are initialized to engender the fault-tolerant control algorithm. The fault diagnosis algorithm can detect 60 Hall fault phenomena in total as well as all detections can be fulfilled in 1/138 rotor rotation period. The fault-tolerant control algorithm can achieve a smooth torque production which means the same control effect as normal control mode (with three Hall sensors). Finally, the PMSM bench test verifies the accuracy and rapidity of fault diagnosis and fault-tolerant control strategies. The fault diagnosis algorithm can detect all Hall sensor faults promptly and fault-tolerant control algorithm allows the PMSM to face failure conditions of one or two Hall sensor(s). In addition, the transitions between health-control and fault-tolerant control conditions are smooth without any additional noise and harshness. Proposed algorithms can deal with the Hall sensor faults of PMSM in real applications, and can be provided to realize the fault diagnosis and fault-tolerant control of PMSM.

Song, Ziyou; Li, Jianqiu; Ouyang, Minggao; Gu, Jing; Feng, Xuning; Lu, Dongbin

2013-07-01

78

Physiochemical Evidence of Faulting Processes and Modeling of Fluid in Evolving Fault Systems in Southern California  

SciTech Connect

Our study targets recent (Plio-Pleistocene) faults and young (Tertiary) petroleum fields in southern California. Faults include the Refugio Fault in the Transverse Ranges, the Ellwood Fault in the Santa Barbara Channel, and most recently the Newport- Inglewood in the Los Angeles Basin. Subsurface core and tubing scale samples, outcrop samples, well logs, reservoir properties, pore pressures, fluid compositions, and published structural-seismic sections have been used to characterize the tectonic/diagenetic history of the faults. As part of the effort to understand the diagenetic processes within these fault zones, we have studied analogous processes of rapid carbonate precipitation (scaling) in petroleum reservoir tubing and manmade tunnels. From this, we have identified geochemical signatures in carbonate that characterize rapid CO2 degassing. These data provide constraints for finite element models that predict fluid pressures, multiphase flow patterns, rates and patterns of deformation, subsurface temperatures and heat flow, and geochemistry associated with large fault systems.

Boles, James [Professor

2013-05-24

79

Synthetic Consolidants Attacked by Melanin-Producing Fungi: Case Study of the Biodeterioration of Milan (Italy) Cathedral Marble Treated with Acrylics?  

PubMed Central

Monuments and artistic stone surfaces are often consolidated and protected with synthetic polymers, in particular, acrylics. Although it is generally thought that acrylic polymers are resistant to biodeterioration, we report for the first time the systematic occurrence of dematiaceous meristematic fungi on many marble samples of the cathedral in Milan (Italy) previously treated with this material. Fourier transform infrared spectroscopy applied to the Milan cathedral stone samples revealed characteristic features of biodeteriorated synthetic resins that differentiated them from the aged but nonbiodeteriorated samples. Samples showing biological colonization were analyzed for the presence of fungi. Cultivation and morphological characterization and methods independent from cultivation, such as denaturing gradient gel electrophoresis coupled with partial 18S rRNA gene sequencing and immunofluorescence staining with melanin-binding antibodies, showed that melanin-producing species are heavily present on stone surfaces protected with acrylic resins. This observation raises the question of the effectiveness of acrylics in protecting stone artworks. PMID:17071788

Cappitelli, Francesca; Nosanchuk, Joshua D.; Casadevall, Arturo; Toniolo, Lucia; Brusetti, Lorenzo; Florio, Sofia; Principi, Pamela; Borin, Sara; Sorlini, Claudia

2007-01-01

80

Synthetic consolidants attacked by melanin-producing fungi: case study of the biodeterioration of Milan (Italy) cathedral marble treated with acrylics.  

PubMed

Monuments and artistic stone surfaces are often consolidated and protected with synthetic polymers, in particular, acrylics. Although it is generally thought that acrylic polymers are resistant to biodeterioration, we report for the first time the systematic occurrence of dematiaceous meristematic fungi on many marble samples of the cathedral in Milan (Italy) previously treated with this material. Fourier transform infrared spectroscopy applied to the Milan cathedral stone samples revealed characteristic features of biodeteriorated synthetic resins that differentiated them from the aged but nonbiodeteriorated samples. Samples showing biological colonization were analyzed for the presence of fungi. Cultivation and morphological characterization and methods independent from cultivation, such as denaturing gradient gel electrophoresis coupled with partial 18S rRNA gene sequencing and immunofluorescence staining with melanin-binding antibodies, showed that melanin-producing species are heavily present on stone surfaces protected with acrylic resins. This observation raises the question of the effectiveness of acrylics in protecting stone artworks. PMID:17071788

Cappitelli, Francesca; Nosanchuk, Joshua D; Casadevall, Arturo; Toniolo, Lucia; Brusetti, Lorenzo; Florio, Sofia; Principi, Pamela; Borin, Sara; Sorlini, Claudia

2007-01-01

81

Microprocessor entomology: a taxonomy of design faults in COTS microprocessors  

Microsoft Academic Search

The rapid increase of the complexity of high-performance COTS (Commercial Off-The-Shelf) microprocessors has led to continuing post-design discoveries of numerous design faults, called “errata” by the manufacturers. This paper presents a systematic framework, the Design Fault Taxonomy, for the study of such design faults. Based on the proposed methodology, an in-depth analysis of design faults uncovered in the Intel Pentium

Algirdas Avizienis; Yutao He

1999-01-01

82

Normal Fault Visualization  

NSDL National Science Digital Library

This module demonstrates the motion on an active normal fault. Faulting offsets three horizontal strata. At the end of the faulting event, surface topography has been generated. The upper rock layer is eroded by clicking on the 'begin erosion' button. The operator can manipulate the faulting motion, stopping and reversing motion on the fault at any point along the transit of faulting. The action of erosion is also interactive. One possible activity is an investigation of the control of different faulting styles on regional landscape form. This visual lends itself to an investigation of fault motion, and a comparison of types of faults. The interactive normal faulting visual could be compared to other interactive visuals depicting thrust faults, reverse faults, and strike slip faults (interactive animations of these fault types can be found by clicking on 'Media Types' at top red bar, then 'Animations', then 'Faults'). By comparing the interactive images of different types of faulting with maps of terrains dominated by different faulting styles, students are aided in conceptualizing how certain faulting styles produce distinctive landforms on the earth's surface (e.g., ridge and valley topography [thrust faulting dominant] versus basin-and-range topography [normal faulting dominant]). Jimm Myers, geology professor at the University of Wyoming, originated the concept of The Magma Foundry, a website dedicated to improving Earth science education across the grade levels. The Magma Foundry designs and creates modular, stand-alone media components that can be utilized in a variety of pedagogical functions in courses and labs.

Myers, Jimm

83

CMOS Bridging Fault Detection  

Microsoft Academic Search

The authors compare the performance of two test generation techniques, stuck fault testing and current testing, when applied to CMOS bridging faults. Accurate simulation of such faults mandated the development of several new design automation tools, including an analog-digital fault simulator. The results of this simulation are analyzed. It is shown that stuck fault test generation, while inherently incapable of

Thomas M. Storey; Wojciech Maly

1990-01-01

84

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.

85

The Cathedral of S. Giorgio in Ragusa Ibla (Italy): characterization of construction materials and their chromatic alteration  

NASA Astrophysics Data System (ADS)

The Cathedral of St. Giorgio in Ragusa Ibla (Sicily) is one of the most important Baroque monuments of eastern Sicily. The restoration of the monument underway has put forward notable questions regarding the stone materials used and their state of degradation. The façade appears to be made mainly of a creamy white calcarenite, and of mortars and plasters. However, detailed analysis has highlighted a more complex use of the raw material. The mortar and plaster have a different composition in regards to their architectural use while the natural stone material is distinguished not only by a creamy-white calcarenite but also by a dark coloured bituminous calcarenite (pitch rock), which now appears whiter because of superficial chromatic alterations. This process was reproduced in the laboratory using an accelerated aging technique on samples of bituminous calcarenite, which allowed the cause of the alternation to be identified as photo-oxidation of the asphaltenes. Following this process of photo-oxidation, other forms of chromatic alterations affected the façade (brown orange-coloured patinas). FTIR, Scanning Electron Microscope and thin section microscopic observation allowed the characterization of also the products of this process to be carried out, highlighting the complex mechanism which the processes underwent.

Barone, Germana; La Russa, Mauro Francesco; Lo Giudice, Antonino; Mazzoleni, Paolo; Pezzino, Antonino

2008-08-01

86

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

87

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

88

Flight elements: Fault detection and fault management  

NASA Technical Reports Server (NTRS)

Fault management for an intelligent computational system must be developed using a top down integrated engineering approach. An approach proposed includes integrating the overall environment involving sensors and their associated data; design knowledge capture; operations; fault detection, identification, and reconfiguration; testability; causal models including digraph matrix analysis; and overall performance impacts on the hardware and software architecture. Implementation of the concept to achieve a real time intelligent fault detection and management system will be accomplished via the implementation of several objectives, which are: Development of fault tolerant/FDIR requirement and specification from a systems level which will carry through from conceptual design through implementation and mission operations; Implementation of monitoring, diagnosis, and reconfiguration at all system levels providing fault isolation and system integration; Optimize system operations to manage degraded system performance through system integration; and Lower development and operations costs through the implementation of an intelligent real time fault detection and fault management system and an information management system.

Lum, H.; Patterson-Hine, A.; Edge, J. T.; Lawler, D.

1990-01-01

89

Transition Fault Simulation  

Microsoft Academic Search

Delay fault testing is becoming more important as VLSI chips become more complex. Components that are fragments of functions, such as those in gate-array designs, need a general model of a delay fault and a feasible method of generating test patterns and simulating the fault. The authors present such a model, called a transition fault, which when used with parallel-pattern,

John Waicukauski; Eric Lindbloom; Barry Rosen; Vijay Iyengar

1987-01-01

90

Diagnosis of instrument fault  

Microsoft Academic Search

The diagnosis of faults in instrumentation equipment can often be confused with faults in the system. The correct diagnosis of instrument faults is of importance. Here it is described how to detect instrument faults in non-linearity. Time-varying processes that include uncertainties such as modelling error, parameter ambiguity, and input and output noise. The design of state estimation filters with zero

K. Watanabe; A. Komori; T. Kiyama

1994-01-01

91

Neural Network Expert System in the Application of Tower Fault Diagnosis  

NASA Astrophysics Data System (ADS)

For the corresponding fuzzy relationship between the fault symptoms and the fault causes in the process of tower crane operation, this paper puts forward a kind of rapid new method of fast detection and diagnosis for common fault based on neural network expert system. This paper makes full use of expert system and neural network advantages, and briefly introduces the structure, function, algorithm and realization of the adopted system. Results show that the new algorithm is feasible and can achieve rapid faults diagnosis.

Liu, Xiaoyang; Xia, Zhongwu; Tao, Zhiyong; Zhao, Zhenlian

92

Fault analysis based on fault reporting in JSP software development  

Microsoft Academic Search

A fault analysis procedure is proposed for software development using JSP (Jackson structured programming). In the procedure, it is assumed that developers submit a fault report, which includes information (such as fault type, cause of fault and product) on actual fault correction activities. The procedure can identify the step in the JSP process at which fault might be introduced. Fault

Yukio MOHRI; T. Kikuno

1991-01-01

93

Loading of the san andreas fault by flood-induced rupture of faults beneath the salton Sea  

USGS Publications Warehouse

The southern San Andreas fault has not experienced a large earthquake for approximately 300 years, yet the previous five earthquakes occurred at ???180-year intervals. Large strike-slip faults are often segmented by lateral stepover zones. A Movement on smaller faults within a stepover zone could perturb the main fault segments and potentially trigger a large earthquake. The southern San Andreas fault terminates in an extensional stepover zone beneath the Salton Sea-a lake that has experienced periodic flooding and desiccation since the late Holocene. Here we reconstruct the magnitude and timing of fault activity beneath the Salton Sea over several earthquake cycles. We observe coincident timing between flooding events, stepover fault displacement and ruptures on the San Andreas fault. Using Coulomb stress models, we show that the combined effect of lake loading, stepover fault movement and increased pore pressure could increase stress on the southern San Andreas fault to levels sufficient to induce failure. We conclude that rupture of the stepover faults, caused by periodic flooding of the palaeo-Salton Sea and by tectonic forcing, had the potential to trigger earthquake rupture on the southern San Andreas fault. Extensional stepover zones are highly susceptible to rapid stress loading and thus the Salton Sea may be a nucleation point for large ruptures on the southern San Andreas fault. ?? 2011 Macmillan Publishers Limited. All rights reserved.

Brothers, D.; Kilb, D.; Luttrell, K.; Driscoll, N.; Kent, G.

2011-01-01

94

Pliocene - Quaternary Faults and Potential Seismic Hazards in Southern Nevada  

NASA Astrophysics Data System (ADS)

Known Quaternary faults in the Central Basin & Range Province (CBR) have a southern limit at about 35 degrees 30' N latitude, south of Las Vegas, NV. The boundary is generally aligned with the southern end of the Sierra Nevada and strike-slip faults, such as those in Death Valley, that accommodate the right-lateral motion transferred from the plate boundary to east of the Sierra Nevada. Between ~8-4 Ma, the time range when the right-lateral motion was transferred to the east, CBR tectonism changed from rapid extension, low-angle normal faulting, and strike-slip faulting in the center to strike-slip faulting in the west and slower extension along normal faults in the middle and eastern CBR. Timing data from known <6-4 Ma CBR normal faults near the southern limit of Quaternary faulting show synchronicity with strike-slip faults in the southern Walker Lane and Eastern California shear zone on the west. Excellent examples of young faults in southern Nevada lie in Las Vegas basin and eastward to Mesquite. Our detailed stratigraphic and fault model of Las Vegas basin combined with shear-wave data shows significant ground shaking would occur there as a result of large magnitude earthquakes on almost any CBR fault. Faults in southern Nevada with documented Holocene activity include the normal-slip California Wash and Black Hills faults, and the strike-slip Mead Slope, Rock Valley, Pahrump Valley and Amargosa Valley faults / fault zones. The latter two faults aid in accommodating the step-over of some plate boundary slip from the San Andreas fault to faults east of the Sierra Nevada. Potential earthquake magnitudes for these faults range from ~M6.5-7.2 based on surface rupture lengths and documented single-event offsets. The <6-4 Ma central CBR faults appear to accommodate a change in shape of the rock volume between the strike-slip faults on the west and the Colorado Plateau to the east. We suggest that the shape change results from NW-motion of strike-slip fault blocks in the west and deformation on long segmented normal faults in the east.

Taylor, W. J.; Wagoner, J.; Depolo, C. M.; Luke, B.; Louie, J.

2005-12-01

95

Depiction of facial nerve paresis in the gallery of portraits carved in stone by George Matthew the Dalmatian on the Sibenik Cathedral dating from the 15th century.  

PubMed

The introductory segment of this paper briefly describes George Matthew the Dalmatian, the architect who, between 1441 and 1473, oversaw the construction of the Cathedral of St. James in Sibenik, a city on the Croatian side of the Adriatic coast. Of the most impressive details included in this monumental construction and sculptural flamboyant gothic production infused with distinctive Dalmatian spirit is a frieze of 71 stone and three lion portraits encircling the outer apse wall. From the intriguing amalgamation of portraits of anonymous people this master came across in his surrounding, the fiftieth head in the row has been selected for this occasion. On the face of a younger man the authors have recognized and described pathognomonic right-sided facial nerve paresis. The question posed here is whether this is coincidental or it represents the master's courage, given that instead of famous people in the cathedral he situated not only ordinary people but also those "labelled" and traditionally marginalized, thus, in the most beautiful manner, foreshadowing the forthcoming spirit of Humanism and Renaissance in Croatian and European art. PMID:21755741

Skrobonja, Ante; Culina, Tatjana

2011-06-01

96

Off-fault damage and acoustic emission distributions during the evolution of structurally complex faults over series of stick-slip events  

NASA Astrophysics Data System (ADS)

Variations in fault structure, for example, surface roughness and deformation zone width, influence the location and dynamics of large earthquakes as well as the distribution of small seismic events. In nature, changes in fault roughness and seismicity characteristics can rarely be studied simultaneously, so that little is known about their interaction and evolution. Here, we investigate the connection between fault structure and near-fault distributions of seismic events over series of stick-slip cycles in the laboratory. We conducted a set of experiments on rough faults that developed from incipient fracture surfaces. We monitored stress and seismic activity which occurred in the form of acoustic emissions (AEs). We determined AE density distributions as a function of fault normal distance based on high-accuracy hypocentre locations during subsequent interslip periods. The characteristics of these distributions were closely connected to different structural units of the faults, that is, the fault core, off-fault and background damage zone. The core deformation zone was characterized by consistently high seismic activity, whereas the off-fault damage zone displayed a power-law decay of seismic activity with increasing distance from the fault core. The exponents of the power-law-distributed off-fault activity increased with successive stick-slip events so that later interslip periods showed a more rapid spatial decay of seismic activity from the fault. The increase in exponents was strongest during the first one to three interslip periods and reached approximately constant values thereafter. The relatively rapid spatial decay of AE events during later interslip periods is likely an expression of decreasing fault zone complexity and roughness. Our results indicate a close relationship between fault structure, stress and seismic off-fault activity. A more extensive mapping of seismic off-fault activity-decay has the potential to significantly advance the understanding of fault zone properties including variations in fault roughness and stress.

Goebel, T. H. W.; Becker, T. W.; Sammis, C. G.; Dresen, G.; Schorlemmer, D.

2014-06-01

97

Optimal fault location  

E-print Network

sequence of events newly obtained recording belongs. Software prototype of the proposed automated fault location analysis is developed using Java programming language. Fault location analysis is automatically triggered by appearance of new event files in a...

Knezev, Maja

2008-10-10

98

Optimal fault location  

E-print Network

sequence of events newly obtained recording belongs. Software prototype of the proposed automated fault location analysis is developed using Java programming language. Fault location analysis is automatically triggered by appearance of new event files in a...

Knezev, Maja

2009-05-15

99

Every Place Has Its Faults  

NSDL National Science Digital Library

This site covers the four main types of faults (not including growth faults): the normal fault, reverse fault, transcurrent (strike-slip) fault, and thrust fault. Animations show the type of movement for each different type of fault. There is a section on the initial stage of a landform, containing a diagram of a graben and horst system. Also included are photographs of fault scarps along Hebgen Lake, Montana.

Mustoe, M.

2011-04-20

100

Fault zone hydrogeology  

NASA Astrophysics Data System (ADS)

Deformation along faults in the shallow crust (< 1 km) introduces permeability heterogeneity and anisotropy, which has an important impact on processes such as regional groundwater flow, hydrocarbon migration, and hydrothermal fluid circulation. Fault zones have the capacity to be hydraulic conduits connecting shallow and deep geological environments, but simultaneously the fault cores of many faults often form effective barriers to flow. The direct evaluation of the impact of faults to fluid flow patterns remains a challenge and requires a multidisciplinary research effort of structural geologists and hydrogeologists. However, we find that these disciplines often use different methods with little interaction between them. In this review, we document the current multi-disciplinary understanding of fault zone hydrogeology. We discuss surface- and subsurface observations from diverse rock types from unlithified and lithified clastic sediments through to carbonate, crystalline, and volcanic rocks. For each rock type, we evaluate geological deformation mechanisms, hydrogeologic observations and conceptual models of fault zone hydrogeology. Outcrop observations indicate that fault zones commonly have a permeability structure suggesting they should act as complex conduit-barrier systems in which along-fault flow is encouraged and across-fault flow is impeded. Hydrogeological observations of fault zones reported in the literature show a broad qualitative agreement with outcrop-based conceptual models of fault zone hydrogeology. Nevertheless, the specific impact of a particular fault permeability structure on fault zone hydrogeology can only be assessed when the hydrogeological context of the fault zone is considered and not from outcrop observations alone. To gain a more integrated, comprehensive understanding of fault zone hydrogeology, we foresee numerous synergistic opportunities and challenges for the discipline of structural geology and hydrogeology to co-evolve and address remaining challenges by co-locating study areas, sharing approaches and fusing data, developing conceptual models from hydrogeologic data, numerical modeling, and training interdisciplinary scientists.

Bense, V. F.; Gleeson, T.; Loveless, S. E.; Bour, O.; Scibek, J.

2013-12-01

101

Transient fault detectors  

Microsoft Academic Search

We present fault detectors for transient faults, (i.e., corruptions of the memory of the processors, but not of the code of\\u000a the processors). We distinguish fault detectors for tasks (i.e., the problem to be solved) from failure detectors for implementations (i.e., the algorithm that solves the problem). The aim of our fault detectors is to detect a memory corruption as

Joffroy Beauquier; Sylvie Delaët; Shlomi Dolev; Sébastien Tixeuil

2007-01-01

102

Sensor noise fault detection  

Microsoft Academic Search

Current sensor FDIR (fault detection, isolation, & recovery) generally focuses on sensor bias and drift anomalies, which require models. However, dead sensors and excessive noise faults are more common in practice. The latter two faults are interesting in that they can be detected using only the measurements from each sensor. The objective of this paper is to show a few

Steve Rogers

2003-01-01

103

Mechanics of discontinuous faults  

Microsoft Academic Search

Fault traces consist of numerous discrete segments, commonly arranged as echelon arrays. In some cases, discontinuities influence the distribution of slip and seismicity along faults. To analyze fault segments, we derive a two-dimensional solution for any number of nonintersecting cracks arbitrarily located in a homogeneous elastic material. The solution includes the elastic interaction between cracks. Crack surfaces are assumed to

P. Segall; D. D. Pollard

1980-01-01

104

Fault tolerant control of spacecraft  

NASA Astrophysics Data System (ADS)

Autonomous multiple spacecraft formation flying space missions demand the development of reliable control systems to ensure rapid, accurate, and effective response to various attitude and formation reconfiguration commands. Keeping in mind the complexities involved in the technology development to enable spacecraft formation flying, this thesis presents the development and validation of a fault tolerant control algorithm that augments the AOCS on-board a spacecraft to ensure that these challenging formation flying missions will fly successfully. Taking inspiration from the existing theory of nonlinear control, a fault-tolerant control system for the RyePicoSat missions is designed to cope with actuator faults whilst maintaining the desirable degree of overall stability and performance. Autonomous fault tolerant adaptive control scheme for spacecraft equipped with redundant actuators and robust control of spacecraft in underactuated configuration, represent the two central themes of this thesis. The developed algorithms are validated using a hardware-in-the-loop simulation. A reaction wheel testbed is used to validate the proposed fault tolerant attitude control scheme. A spacecraft formation flying experimental testbed is used to verify the performance of the proposed robust control scheme for underactuated spacecraft configurations. The proposed underactuated formation flying concept leads to more than 60% savings in fuel consumption when compared to a fully actuated spacecraft formation configuration. We also developed a novel attitude control methodology that requires only a single thruster to stabilize three axis attitude and angular velocity components of a spacecraft. Numerical simulations and hardware-in-the-loop experimental results along with rigorous analytical stability analysis shows that the proposed methodology will greatly enhance the reliability of the spacecraft, while allowing for potentially significant overall mission cost reduction.

Godard

105

Self-induced seismicity due to fluid circulation along faults  

NASA Astrophysics Data System (ADS)

In this paper, we develop a system of equations describing fluid migration, fault rheology, fault thickness evolution and shear rupture during a seismic cycle, triggered either by tectonic loading or by fluid injection. Assuming that the phenomena predominantly take place on a single fault described as a finite permeable zone of variable width, we are able to project the equations within the volumetric fault core onto the 2-D fault interface. From the basis of this `fault lubrication approximation', we simulate the evolution of seismicity when fluid is injected at one point along the fault to model-induced seismicity during an injection test in a borehole that intercepts the fault. We perform several parametric studies to understand the basic behaviour of the system. Fluid transmissivity and fault rheology are key elements. The simulated seismicity generally tends to rapidly evolve after triggering, independently of the injection history and end when the stationary path of fluid flow is established at the outer boundary of the model. This self-induced seismicity takes place in the case where shear rupturing on a planar fault becomes dominant over the fluid migration process. On the contrary, if healing processes take place, so that the fluid mass is trapped along the fault, rupturing occurs continuously during the injection period. Seismicity and fluid migration are strongly influenced by the injection rate and the heterogeneity.

Aochi, Hideo; Poisson, Blanche; Toussaint, Renaud; Rachez, Xavier; Schmittbuhl, Jean

2014-03-01

106

One-Cycle Fault Interruption at 500 kV: System Benefits and Breaker Design  

Microsoft Academic Search

The need for ultra-rapid fault interruption is identified on the basis of improvements to generator stability and the power transmission capability of the BPA 500 kV system. The development of a modified 500 kV air blast circuit breaker and a special fault sensor, which in combination should reduce total fault duration to essentially one cycle, is then described.

R. O. Berglund; W. A. Mittelstadt; M. L. Shelton; P. Barkan; C. G. Dewey; K. M. Skreiner

1974-01-01

107

Fault-Tree Compiler  

NASA Technical Reports Server (NTRS)

Fault-Tree Compiler (FTC) program, is software tool used to calculate probability of top event in fault tree. Gates of five different types allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language easy to understand and use. In addition, program supports hierarchical fault-tree definition feature, which simplifies tree-description process and reduces execution time. Set of programs created forming basis for reliability-analysis workstation: SURE, ASSIST, PAWS/STEM, and FTC fault-tree tool (LAR-14586). Written in PASCAL, ANSI-compliant C language, and FORTRAN 77. Other versions available upon request.

Butler, Ricky W.; Boerschlein, David P.

1993-01-01

108

Faults of Southern California  

NSDL National Science Digital Library

This interactive map displays faults for five regions in Southern California. Clicking on a region links to an enlarged relief map of the area, with local faults highlighted in colors. Users can click on individual faults to access pages with more detailed information, such as type, length, nearest communities, and a written description. In all of the maps, the segment of the San Andreas fault that is visible is highlighted in red, and scales for distances and elevations are provided. There is also a link to an alphabetical listing of faults by name.

109

A CATHEDRAL OF DETECTORS  

E-print Network

a particular heat-sensitive protein was activated. A laser was then used to induce heat shock and etch out the pattern. THE ART IN YOUR ENGINE A vortex of flame swirls inside a combustion chamber. Researchers at the French National Aerospace Research Center (ONERA) caught this shot while examining combustion inside

Monteiro, Antónia

110

Diagnosing CMOS bridging faults with stuck-at fault dictionaries  

Microsoft Academic Search

It is shown that the traditional approach to diagnosing stuck-at faults with fault dictionaries generated for stuck-at faults is not appropriate for diagnosing CMOS bridging faults. A novel technique for using stuck-at-fault dictionaries to diagnose bridging faults is described. Teradyne's LASAR was used to simulate bridging and stuck-at faults in a number of combinational circuits, including parity trees, multiplexers, and

Steven D. Millman; Edward J. McCluskey; John M. Acken

1990-01-01

111

Fuzzy fault diagnostic system based on fault tree analysis  

Microsoft Academic Search

A method is presented for process fault diagnosis using information from fault tree analysis and uncertainty\\/imprecision of data. Fault tree analysis, which has been used as a method of system reliability\\/safety analysis, provides a procedure for identifying failures within a process. A fuzzy fault diagnostic system is constructed which uses the fuzzy fault tree analysis to represent a knowledge of

Zong-Xiao Yang; Kazuhiko SUZUKI; Yukiyasu SHIMADA; Hayatoshi SAYAMA

1995-01-01

112

Frictional constraints on crustal faulting  

USGS Publications Warehouse

We consider how variations in fault frictional properties affect the phenomenology of earthquake faulting. In particular, we propose that lateral variations in fault friction produce the marked heterogeneity of slip observed in large earthquakes. We model these variations using a rate- and state-dependent friction law, where we differentiate velocity-weakening behavior into two fields: the strong seismic field is very velocity weakening and the weak seismic field is slightly velocity weakening. Similarly, we differentiate velocity-strengthening behavior into two fields: the compliant field is slightly velocity strengthening and the viscous field is very velocity strengthening. The strong seismic field comprises the seismic slip concentrations, or asperities. The two "intermediate" fields, weak seismic and compliant, have frictional velocity dependences that are close to velocity neutral: these fields modulate both the tectonic loading and the dynamic rupture process. During the interseismic period, the weak seismic and compliant regions slip aseismically, while the strong seismic regions remain locked, evolving into stress concentrations that fail only in main shocks. The weak seismic areas exhibit most of the interseismic activity and aftershocks but can also creep seismically. This "mixed" frictional behavior can be obtained from a sufficiently heterogenous distribution of the critical slip distance. The model also provides a mechanism for rupture arrest: dynamic rupture fronts decelerate as they penetrate into unloaded complaint or weak seismic areas, producing broad areas of accelerated afterslip. Aftershocks occur on both the weak seismic and compliant areas around a fault, but most of the stress is diffused through aseismic slip. Rapid afterslip on these peripheral areas can also produce aftershocks within the main shock rupture area by reloading weak fault areas that slipped in the main shock and then healed. We test this frictional model by comparing the seismicity and the coseismic slip for the 1966 Parkfield, 1979 Coyote Lake, and 1984 Morgan Hill earthquakes. The interevent seismicity and aftershocks appear to occur on fault areas outside the regions of significant slip: these regions are interpreted as either weak seismic or compliant, depending on whether or not they manifest interevent seismicity.

Boatwright, J.; Cocco, M.

1996-01-01

113

Complex Paleotopography and Faulting near the Elsinore Fault, Coyote Mountains, southern California  

NASA Astrophysics Data System (ADS)

The Coyote Mountains of southern California are bounded on the southwest by the Elsinore Fault, an active dextral fault within the San Andreas Fault zone. According to Axen and Fletcher (1998) and Dorsey and others (2011), rocks exposed in these mountains comprise a portion of the hanging wall of the east-vergent Salton Detachment Fault, which was active from the late Miocene-early Pliocene to Ca. 1.1-1.3 Ma. Detachment faulting was accompanied by subsidence, resulting in deposition of a thick sequence of marine and nonmarine sedimentary rocks. Regional detachment faulting and subsidence ceased with the inception of the Elsinore Fault, which has induced uplift of the Coyote Mountains. Detailed geologic mapping in the central Coyote Mountains supports the above interpretation and adds some intriguing details. New discoveries include a buttress unconformity at the base of the Miocene/Pliocene section that locally cuts across strata at an angle so high that it could be misinterpreted as a fault. We thus conclude that the syn-extension strata were deposited on a surface with very rugged topography. We also discovered that locally-derived nonmarine gravel deposits exposed near the crest of the range, previously interpreted as part of the Miocene Split Mountain Group by Winker and Kidwell (1996), unconformably overlie units of the marine Miocene/Pliocene Imperial Group and must therefore be Pliocene or younger. The presence of such young gravel deposits on the crest of the range provides evidence for its rapid uplift. Additional new discoveries flesh out details of the structural history of the range. We mapped just two normal faults, both of which were relatively minor, thus supporting Axen and Fletcher's assertion that the hanging wall block of the Salton Detachment Fault had not undergone significant internal deformation during extension. We found abundant complex synthetic and antithetic strike-slip faults throughout the area, some of which offset Quaternary alluvial deposits. We interpret these faults as Riedel shears of the Elsinore Fault that distribute dextral strain over an area at least 2 km wide. Finally, our mapping of the Elsinore Fault itself reveals two releasing bends that are superimposed on the overall transpressive regime in the area. Axen, G.J. and Fletcher, J.M., 1998, Hall Volume, GSA, p. 365-392. Dorsey, R.J., Housen, B.A., Janecke, S.U., Fanning, C. M., Spears, A.L.F., 2011, GSA Bulletin, v. 123, p. 771-793. Winker, C.D. and Kidwell, S.M., 1996, Field Conference Guide, Pacific Section AAPG/SEPM, Book 80, p. 295-336.

Brenneman, M. J.; Bykerk-Kauffman, A.

2012-12-01

114

Rapid tooling  

Microsoft Academic Search

Rapid tooling can be seen as the second wave in rapid prototyping because, with rapid tooling, the production process can be prototyped instead of the final product. This article discusses and compares several existing processes available for rapid tooling. For each process, the product size and the number of shots is estimated. Since this text was part of the Internet

Eric Radstok

1999-01-01

115

Its Not My Fault  

NSDL National Science Digital Library

Students become familiar with strike-slip faults, normal faults, reverse faults and visualize these geological structures using cardboard or a plank of wood, a stack of books, protractor, and a spring scale. The resource is part of the teacher's guide accompanying the video, NASA SCI Files: The Case of the Shaky Quake. Lesson objectives supported by the video, additional resources, teaching tips and an answer sheet are included in the teacher's guide.

116

The San Andreas Fault  

NSDL National Science Digital Library

This United States Geological Survey (USGS) publication discusses the San Andreas Fault in California; specifically what has caused the fault, where it is located, surface features that characterize it, and movement that has occurred. General earthquake information includes an explanation of what earthquakes are, and earthquake magnitude versus intensity. Earthquakes that have occurred along the fault are covered, as well as where the next large one may occur and what can be done about large earthquakes in general.

Schulz, Sandra; Wallace, Robert

117

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

118

Fault simulation and test generation for small delay faults  

E-print Network

Delay faults are an increasingly important test challenge. Traditional delay fault models are incomplete in that they model only a subset of delay defect behaviors. To solve this problem, a more realistic delay fault model has been developed which...

Qiu, Wangqi

2007-04-25

119

Fault detection and fault tolerance in robotics  

NASA Technical Reports Server (NTRS)

Robots are used in inaccessible or hazardous environments in order to alleviate some of the time, cost and risk involved in preparing men to endure these conditions. In order to perform their expected tasks, the robots are often quite complex, thus increasing their potential for failures. If men must be sent into these environments to repair each component failure in the robot, the advantages of using the robot are quickly lost. Fault tolerant robots are needed which can effectively cope with failures and continue their tasks until repairs can be realistically scheduled. Before fault tolerant capabilities can be created, methods of detecting and pinpointing failures must be perfected. This paper develops a basic fault tree analysis of a robot in order to obtain a better understanding of where failures can occur and how they contribute to other failures in the robot. The resulting failure flow chart can also be used to analyze the resiliency of the robot in the presence of specific faults. By simulating robot failures and fault detection schemes, the problems involved in detecting failures for robots are explored in more depth.

Visinsky, Monica; Walker, Ian D.; Cavallaro, Joseph R.

1992-01-01

120

Folds and Faults  

NSDL National Science Digital Library

In this activity, students will learn how rock layers are folded and faulted and how to represent these structures in maps and cross sections. They will use playdough to represent layers of rock and make cuts in varying orientations to represent faults and other structures.

121

SFT: scalable fault tolerance  

Microsoft Academic Search

In this paper we will present a new technology that we are currently developing within the SFT: Scalable Fault Tolerance FastOS project which seeks to implement fault tolerance at the operating system level. Major design goals include dynamic reallocation of resources to allow continuing execution in the presence of hardware failures, very high scalability, high efficiency (low overhead), and transparency---requiring

Fabrizio Petrini; Jarek Nieplocha; Vinod Tipparaju

2006-01-01

122

Practical Byzantine Fault Tolerance  

Microsoft Academic Search

This paper describes a new replication algorithm that is able to tolerate Byzantine faults. We believe that Byzantine- fault-tolerant algorithms will be increasingly important in the future because malicious attacks and software errors are increasingly common and can cause faulty nodes to exhibit arbitrary behavior. Whereas previous algorithms assumed a synchronous system or were too slow to be used in

Miguel Castro; Barbara Liskov

1999-01-01

123

Puente Hills Fault Visualization  

NSDL National Science Digital Library

Puente Hills Fault posses a disaster threat for Los Angeles region. Earthquake simulations on this fault estimate damages over $250 billion. Visualizations created by SDSC using the data computed from earthquake simulations helps one to fathom the propagation of siesmic waves and the areas affected.

124

Fault rocks lab  

NSDL National Science Digital Library

This lab is intended to give students some hands on experience looking at fault rocks with a suite of cataclasites and mylonites I have collected. The focus is on identifying key textural features in both hand sample and thin section and understanding how deformation within a fault zone varies with depth.

Singleton, John

125

Solar system fault detection  

DOEpatents

A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

Farrington, R.B.; Pruett, J.C. Jr.

1984-05-14

126

West Coast Tsunami: Cascadia's Fault?  

NASA Astrophysics Data System (ADS)

The tragedies of 2004 Sumatra and 2011 Japan tsunamis exposed the limits of our knowledge in preparing for devastating tsunamis. The 1,100-km coastline of the Pacific coast of North America has tectonic and geological settings similar to Sumatra and Japan. The geological records unambiguously show that the Cascadia fault had caused devastating tsunamis in the past and this geological process will cause tsunamis in the future. Hypotheses of the rupture process of Cascadia fault include a long rupture (M9.1) along the entire fault line, short ruptures (M8.8 - M9.1) nucleating only a segment of the coastline, or a series of lesser events of M8+. Recent studies also indicate an increasing probability of small rupture occurring at the south end of the Cascadia fault. Some of these hypotheses were implemented in the development of tsunami evacuation maps in Washington and Oregon. However, the developed maps do not reflect the tsunami impact caused by the most recent updates regarding the Cascadia fault rupture process. The most recent study by Wang et al. (2013) suggests a rupture pattern of high- slip patches separated by low-slip areas constrained by estimates of coseismic subsidence based on microfossil analyses. Since this study infers that a Tokohu-type of earthquake could strike in the Cascadia subduction zone, how would such an tsunami affect the tsunami hazard assessment and planning along the Pacific Coast of North America? The rapid development of computing technology allowed us to look into the tsunami impact caused by above hypotheses using high-resolution models with large coverage of Pacific Northwest. With the slab model of MaCrory et al. (2012) (as part of the USGS slab 1.0 model) for the Cascadia earthquake, we tested the above hypotheses to assess the tsunami hazards along the entire U.S. West Coast. The modeled results indicate these hypothetical scenarios may cause runup heights very similar to those observed along Japan's coastline during the 2011 Japan tsunami,. Comparing to a long rupture, the Tohoku-type rupture may cause more serious impact at the adjacent coastline, independent of where it would occur in the Cascadia subduction zone. These findings imply that the Cascadia tsunami hazard may be greater than originally thought.

Wei, Y.; Bernard, E. N.; Titov, V.

2013-12-01

127

Transient fault modeling and fault injection simulation  

E-print Network

An accurate transient fault model is presented in this thesis. A 7-term exponential current upset model is derived from the results of a device-level, 3-dimensional, single-event-upset simulation. A curve-fitting algorithm is used to extract...

Yuan, Xuejun

2012-06-07

128

System fault diagnostics using fault tree analysis  

Microsoft Academic Search

Over the last 50 years advances in technology have led to an increase in the complexity and sophistication of systems. More complex systems can be harder to maintain and the root cause of a fault more difficult to isolate. Down-time resulting from a system failure can be dangerous or expensive depending on the type of system. In aircraft systems the

E. E. Hurdle; L. M. Bartlett; J. D. Andrews

2008-01-01

129

Measuring fault tolerance with the FTAPE fault injection tool  

NASA Technical Reports Server (NTRS)

This paper describes FTAPE (Fault Tolerance And Performance Evaluator), a tool that can be used to compare fault-tolerant computers. The major parts of the tool include a system-wide fault-injector, a workload generator, and a workload activity measurement tool. The workload creates high stress conditions on the machine. Using stress-based injection, the fault injector is able to utilize knowledge of the workload activity to ensure a high level of fault propagation. The errors/fault ratio, performance degradation, and number of system crashes are presented as measures of fault tolerance.

Tsai, Timothy K.; Iyer, Ravishankar K.

1995-01-01

130

Thyristor controlled ground fault current limiting system for ungrounded power distribution systems  

SciTech Connect

A thyristor controlled ground fault current limiting system (TGCL) was proposed to prevent one-line ground fault current rises due to increased capacitance to ground. Basic components of the TGCL are a main ground fault current limiter, which rapidly adjusts a compensating reactor level for the capacitance to ground, and the TGCL`s controller. Control is ensured by an in-phase control method for zero-phase sequence voltage and current. The method determines the direction of ground faults and the compensating reactor level. The fast control which can be realized shows the TGCL is a valuable protecting system for high ground fault current distribution systems.

Sugimoto, S.; Neo, S. [Chubu Electric Power Co., Inc., Nagoya (Japan). Electric Power Research and Development Center] [Chubu Electric Power Co., Inc., Nagoya (Japan). Electric Power Research and Development Center; Arita, H.; Kida, J.; Matsui, Y.; Yamagiwa, T. [Hitachi Ltd., Hitachi, Ibaraki (Japan)] [Hitachi Ltd., Hitachi, Ibaraki (Japan)

1996-04-01

131

What's Cooking? Evaluating frictional stress using extractable organic material in fault zones  

NASA Astrophysics Data System (ADS)

The detection of a frictional heating signature is a promising, but elusive, way to measure frictional stress on exhumed faults lacking evidence of melting. We present a new paleothermometer for fault zones that uses the thermal alteration of organic molecules to detect frictional heating along faults. As a rock is heated, temperature-sensitive molecules degrade, increasing the abundance of refractory organic molecules. On the short timescales involved in fault heating, these reactions are strongly temperature dependent and therefore track the maximum temperature achieved during fault slip. Furthermore, because there are no retrograde reactions in these organic systems, the maximum heating signature is preserved. We tested our approach with samples from a pseudotachylyte-bearing thrust fault in the Ghost Rocks Formation, Kodiak, Alaska and applied our approach to several strike-slip and thrust faults. In the Ghost Rocks thrust fault we found higher concentrations of refractory diamondoid compounds in the pseudotachylyte-bearing rocks and lower concentrations in adjacent fault rocks and off-fault samples. The presence of pseudotachylyte indicates significant, rapid heating of these rocks during fault slip. Our finding confirms that this rapid heating is sufficient to measurably alter the thermal maturity of organic molecules. In the other faults we studied, the concentrations of refractory methylphenanthrene molecules was no different between fault and surrounding rock indicating no detectable heating. These results suggests little frictional heating of the fault rocks occurred despite total fault offsets >20 km during burial at 2-4 km. This work represents a promising new avenue for detecting heat signatures along faults that can be applied to a variety of sedimentary rock types and burial depths.

Polissar, P. J.; Savage, H. M.; Sheppard, R. E.; Rowe, C. D.; Brodsky, E. E.

2011-12-01

132

Fault diagnosis of analog circuits  

Microsoft Academic Search

In this paper, various fault location techniques in analog networks are described and compared. The emphasis is on the more recent developments in the subject. Four main approaches for fault location are addressed, examined, and illustrated using simple network examples. In particular, we consider the fault dictionary approach, the parameter identification approach, the fault verification approach, and the approximation approach.

J. W. Bandler; A. E. Salama

1985-01-01

133

Glossary of normal faults  

Microsoft Academic Search

Increased interest in normal faults and extended terranes has led to the development of an increasingly complex terminology. The most important terms are defined in this paper, with original references being given wherever possible, along with examples of current usage.

D. C. P. Peacock; R. J. Knipe; D. J. Sanderson

2000-01-01

134

Long-Term Monitoring of Fresco Paintings in the Cathedral of Valencia (Spain) Through Humidity and Temperature Sensors in Various Locations for Preventive Conservation  

PubMed Central

We describe the performance of a microclimate monitoring system that was implemented for the preventive conservation of the Renaissance frescoes in the apse vault of the Cathedral of Valencia, that were restored in 2006. This system comprises 29 relative humidity (RH) and temperature sensors: 10 of them inserted into the plaster layer supporting the fresco paintings, 10 sensors in the walls close to the frescoes and nine sensors measuring the indoor microclimate at different points of the vault. Principal component analysis was applied to RH data recorded in 2007. The analysis was repeated with data collected in 2008 and 2010. The resulting loading plots revealed that the similarities and dissimilarities among sensors were approximately maintained along the three years. A physical interpretation was provided for the first and second principal components. Interestingly, sensors recording the highest RH values correspond to zones where humidity problems are causing formation of efflorescence. Recorded data of RH and temperature are discussed according to Italian Standard UNI 10829 (1999). PMID:22164100

Zarzo, Manuel; Fernandez-Navajas, Angel; Garcia-Diego, Fernando-Juan

2011-01-01

135

Practical Byzantine Fault Tolerance  

Microsoft Academic Search

Our growing reliance on online services accessible on the Internet demands highly-available systemsthat provide correct service without interruptions. Byzantine faults such as software bugs, operatormistakes, and malicious attacks are the major cause of service interruptions. This thesis describesa new replication algorithm, BFT, that can be used to build highly-available systems that tolerateByzantine faults. It shows, for the first time, how

Miguel Castro

2001-01-01

136

Strongly Fault Secure Logic Networks  

Microsoft Academic Search

Strongly fault secure logic networks are defined and are shown to include totally self-checking networks as a special case. Strongly fault secure networks provide the same protection against assumed faults as totally self-checking networks, and it is shown that when stuck-at faults are assumed a strongly fault secure network can be easily modified to form a totally self-checking network. A

James E. Smith; Gernot Metze

1978-01-01

137

Fault tolerant magnetic bearings  

SciTech Connect

A fault tolerant magnetic bearing system was developed and demonstrated on a large flexible-rotor test rig. The bearing system comprises a high speed, fault tolerant digital controller, three high capacity radial magnetic bearings, one thrust bearing, conventional variable reluctance position sensors, and an array of commercial switching amplifiers. Controller fault tolerance is achieved through a very high speed voting mechanism which implements triple modular redundancy with a powered spare CPU, thereby permitting failure of up to three CPU modules without system failure. Amplifier/cabling/coil fault tolerance is achieved by using a separate power amplifier for each bearing coil and permitting amplifier reconfiguration by the controller upon detection of faults. This allows hot replacement of failed amplifiers without any system degradation and without providing any excess amplifier kVA capacity over the nominal system requirement. Implemented on a large (2440 mm in length) flexible rotor, the system shows excellent rejection of faults including the failure of three CPUs as well as failure of two adjacent amplifiers (or cabling) controlling an entire stator quadrant.

Maslen, E.H.; Sortore, C.K.; Gillies, G.T.; Williams, R.D.; Fedigan, S.J. [Univ. of Virginia, Charlottesville, VA (United States); Aimone, R.J. [Mobile Technology Co., Paulsboro, NJ (United States)

1999-07-01

138

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

139

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

140

Fault-tolerant, Universal Adiabatic Quantum Computation  

E-print Network

Quantum computation has revolutionary potential for speeding computational tasks such as factoring and simulating quantum systems, but the task of constructing a quantum computer is daunting. Adiabatic quantum computation and other ``hands-off" approaches relieve the need for rapid, precise pulsing to control the system, inspiring at least one high-profile effort to realize a hands-off quantum computing device. But is hands-off incompatible with fault-tolerant? Concerted effort and many innovative ideas have not resolved this question but have instead deepened it, linking it to fundamental problems in quantum complexity theory. Here we present a hands-off approach that is provably (a) capable of scalable universal quantum computation in a non-degenerate ground state and (b) fault-tolerant against an analogue of the usual local stochastic fault model. A satisfying physical and numerical argument indicates that (c) it is also fault-tolerant against thermal excitation below a threshold temperature independent of the computation size.

Ari Mizel

2014-03-30

141

RICE UNIVERSITY Fault Detection and Fault Tolerance Methods for  

E-print Network

RICE UNIVERSITY Fault Detection and Fault Tolerance Methods for Robotics by Monica L. Visinsky for their contributions to the dragon. Thanks are also due to Larry, J.D. and Dr. Johnson for their constant help

Cavallaro, Joseph R.

142

Stresses and Faulting  

NSDL National Science Digital Library

This module is designed for students in an introductory structural geology course. While key concepts are described here, it is assumed that the students will have access to a good textbook to augment the information presented here. Learning goals: (1) Understand the role of gravity and rock properties in producing stresses in the shallow Earth. (2) Graphically represent stress states using Mohr diagrams. (3) Determine failure criteria from the results of laboratory experiments. (4) Explore the interaction of gravity-induced and tectonic stresses on fault formation. (5) Apply models of fault formation to predict fault behavior in two natural settings: San Onofre Beach in southern California and Canyonland National Park in Utah. The module is implemented entirely using Microsoft Excel. This program was selected due to its widespread availability and relative ease-of-use. It is assumed that students are familiar with using equations and graphing tools in Excel.

Reinen, Linda

143

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

144

Fault-Scarp Degradation  

NSDL National Science Digital Library

In this exercise, students investigate the evolution of Earth's surface over time, as governed by the balance between constructional (tectonic) processes and destructional (erosional) processes. Introductory materials explain the processes of degradation, including the concepts of weathering-limited versus transport-limited slopes, and diffusion modeling. Using the process of diffusion modeling, students will determine how a slope changes through four 100-year time steps, calculate gradient angles for a fault scarp, and compare parameters calculated for two fault scarps, attempting to determine the age of the scarp created by the older, unknown earthquake. Example problems, study questions, and a bibliography are provided.

Pinter, Nicholas

2010-09-27

145

Fault tree models for fault tolerant hypercube multiprocessors  

NASA Technical Reports Server (NTRS)

Three candidate fault tolerant hypercube architectures are modeled, their reliability analyses are compared, and the resulting implications of these methods of incorporating fault tolerance into hypercube multiprocessors are discussed. In the course of performing the reliability analyses, the use of HARP and fault trees in modeling sequence dependent system behaviors is demonstrated.

Boyd, Mark A.; Tuazon, Jezus O.

1991-01-01

146

On trapdoor faulting at Sierra Negra volcano, Galapagos Sigurjon Jonssona,*, Howard Zebkerb  

E-print Network

. Keywords: volcano deformation; calderas; trapdoor faulting; interferometric synthetic aperture radarOn trapdoor faulting at Sierra Negra volcano, Gala´pagos Sigurjo´n Jo´nssona,*, Howard Zebkerb Rapid uplift observed during 1992­1997 at Sierra Negra volcano, western Gala´pagos, was followed

Amelung, Falk

147

Fault diagnosis of analog circuits  

NASA Astrophysics Data System (ADS)

Theory and algorithms associated with four main categories of modern techniques used to locate faults in analog circuits are presented. These four general approaches are: the fault dictionary (FDA), the parameter identification (PIA), the fault verification (FVA), and the approximation (AA) approaches. The preliminaries and problems associated with the FDA, such as fault dictionary construction, the methods of optimum measurement selection, fault isolation criteria, and efficient methods of fault simulation, are discussed. The PIA techniques that utilize either linear or nonlinear systems of equations for identification of network elements are examined. Description of the FVA includes node-fault diagnosis, branch-fault diagnosis, subnetwork testability conditions, as well as combinatorial techniques, the failure-bound technique, and the network decomposition technique. In the AA, probabilistic methods and optimization-based methods are considered. In addition, the artificial intelligence technique and the different measures of testability are presented. A series of block diagrams is included.

Bandler, J. W.; Salama, A. E.

1985-08-01

148

Transition-fault test generation  

E-print Network

. One way to detect these timing defects is to apply test patterns to the integrated circuit that are generated using the transition-fault model. Unfortunately, industry's current transition-fault test generation schemes produce test sets that are too...

Cobb, Bradley Douglas

2013-02-22

149

Analyzing Fault/Fracture Patterns  

NSDL National Science Digital Library

During a lab period, students go out in the field to an area that contains at least 2 fault/fracture sets. Students measure orientations of faults and make observations about the relationship between different fault sets. After the field trip, the students compile their field data, plot it on a stereonet and write-up a brief report. In this report students will use their field observations and stereonet patterns to determine whether faults are related or unrelated to each other.

Levine, Jamie

150

Examine animations of fault motion  

NSDL National Science Digital Library

Developed for high school students, this Earth science resource provides animations of each of four different fault types: normal, reverse, thrust, and strike-slip faults. Each animation has its own set of movie control buttons, and arrows in each animation indicate the direction of force that causes that particular kind of fault. The introductory paragraph defines the terms fault plane, handing wall, and footwall--features that are labeled at the end of the appropriate animations. Copyright 2005 Eisenhower National Clearinghouse

Education, Terc. C.; Littell, Mcdougal

2003-01-01

151

Fault scaling laws and the temporal evolution of fault systems  

NASA Astrophysics Data System (ADS)

Through an analysis of the temporal evolution of duplex fault systems, this contribution shows that it is unlikely that all faults in a deformed area will conform to a single frequency-size scaling relationship. The development of a duplex leads to different size—frequency relationships for the faults that compose the duplex and those confined to individual horses. The faults that compose the duplex define segments with relatively steep stopes on a log N (number of faults, i.e. frequency) vs log D (displacement magnitude, i.e. size) plot; faults within individual horses define segments with relatively shallow slopes on a log N vs log D plot. The distinction between these two types of faults in a duplex is akin to the distinction between large active faults, which cut the entire seismogenic layer, and small active faults, which do not extend across the seismogenic layer. If, as is often the case, the faults that compose a duplex do not extend across the seismogenic layer, the stepped nature of the resulting log N vs log D plot may make it particularly difficult to assess the contribution of these 'small' faults to regional deformation. Since duplex geometries result in part from anisotropies present in deforming rocks, the anisotropy present in nearly all crustal rocks will affect the size-frequency relationship observed for systems of faults. Different parts of a deforming rock mass are likely to have different initial anisotropies. Combining data on fault systems from markedly different portions of a deforming region may, then, obscure the unique characteristics of the size-frequency relationship in either area and may lead to inaccurate assessments of the relative contributions of 'small' and 'large' faults to regional fault-accommodated strains.

Wojtal, Steven F.

1994-04-01

152

Pulverized fault rocks and damage asymmetry along the Arima-Takatsuki Tectonic Line, Japan  

E-print Network

earthquakes at seismogenic depth may be the basic generation mechanism. In this case, near-fault rocks may be subjected to rapid drops of confining pressure during successive earthquake ruptures, repeatedly fracturing

Ben-Zion, Yehuda

153

Fault-Related Sanctuaries  

Microsoft Academic Search

Beyond the study of historical surface faulting events, this work investigates the possibility, in specific cases, of identifying pre-historical events whose memory survives in myths and legends. The myths of many famous sacred places of the ancient world contain relevant telluric references: \\

L. Piccardi

2001-01-01

154

Fuzzy fault tree analysis  

Microsoft Academic Search

Reliability of products is frequently a prime safety consideration. Interpretation of reliability is both quantitative and qualitative. Extensive quantitative analysis employing probablistic risk assessment has been widely performed to provide predicted hazard or accident minimization. Weibull probability data and information is a vital tool of these quantitative risk assessments, but so are qualitative methods such as fault tree analysis. Qualitative

David P. Weber

1994-01-01

155

Fault-Related Sanctuaries  

NASA Astrophysics Data System (ADS)

Beyond the study of historical surface faulting events, this work investigates the possibility, in specific cases, of identifying pre-historical events whose memory survives in myths and legends. The myths of many famous sacred places of the ancient world contain relevant telluric references: "sacred" earthquakes, openings to the Underworld and/or chthonic dragons. Given the strong correspondence with local geological evidence, these myths may be considered as describing natural phenomena. It has been possible in this way to shed light on the geologic origin of famous myths (Piccardi, 1999, 2000 and 2001). Interdisciplinary researches reveal that the origin of several ancient sanctuaries may be linked in particular to peculiar geological phenomena observed on local active faults (like ground shaking and coseismic surface ruptures, gas and flames emissions, strong underground rumours). In many of these sanctuaries the sacred area is laid directly above the active fault. In a few cases, faulting has affected also the archaeological relics, right through the main temple (e.g. Delphi, Cnidus, Hierapolis of Phrygia). As such, the arrangement of the cult site and content of relative myths suggest that specific points along the trace of active faults have been noticed in the past and worshiped as special `sacred' places, most likely interpreted as Hades' Doors. The mythological stratification of most of these sanctuaries dates back to prehistory, and points to a common derivation from the cult of the Mother Goddess (the Lady of the Doors), which was largely widespread since at least 25000 BC. The cult itself was later reconverted into various different divinities, while the `sacred doors' of the Great Goddess and/or the dragons (offspring of Mother Earth and generally regarded as Keepers of the Doors) persisted in more recent mythologies. Piccardi L., 1999: The "Footprints" of the Archangel: Evidence of Early-Medieval Surface Faulting at Monte Sant'Angelo (Gargano, Italy). European Union of Geophysics Congress, Strasbourg, March 1999. Piccardi L., 2000: Active faulting at Delphi (Greece): seismotectonic remarks and a hypothesis for the geological environment of a myth. Geology, 28, 651-654. Piccardi L., 2001: Seismotectonic Origin of the Monster of Loch Ness. Earth System Processes, Joint Meeting of G.S.A. and G.S.L., Edinburgh, June 2001.

Piccardi, L.

2001-12-01

156

Earthquakes and fault creep on the northern San Andreas fault  

USGS Publications Warehouse

At present there is an absence of both fault creep and small earthquakes on the northern San Andreas fault, which had a magnitude 8 earthquake with 5 m of slip in 1906. The fault has apparently been dormant after the 1906 earthquake. One possibility is that the fault is 'locked' in some way and only produces great earthquakes. An alternative possibility, presented here, is that the lack of current activity on the northern San Andreas fault is because of a lack of sufficient elastic strain after the 1906 earthquake. This is indicated by geodetic measurements at Fort Ross in 1874, 1906 (post-earthquake), and 1969, which show that the strain accumulation in 1969 (69 ?? 10-6 engineering strain) was only about one-third of the strain release (rebound) in the 1906 earthquake (200 ?? 10-6 engineering strain). The large difference in seismicity before and after 1906, with many strong local earthquakes from 1836 to 1906, but only a few strong earthquakes from 1906 to 1976, also indicates a difference of elastic strain. The geologic characteristics (serpentine, fault straightness) of most of the northern San Andreas fault are very similar to the characteristics of the fault south of Hollister, where fault creep is occurring. Thus, the current absence of fault creep on the northern fault segment is probably due to a lack of sufficient elastic strain at the present time. ?? 1979.

Nason, R.

1979-01-01

157

Fault Scarp Offsets and Fault Population Analysis on Dione  

NASA Astrophysics Data System (ADS)

Cassini images of Dione show several fault zones cutting through the moon’s icy surface. We have measured the displacement and length of 271 faults, and estimated the strain occurring in 6 different fault zones. These measurements allow us to quantify the total amount of surface strain on Dione as well as constrain what processes might have caused these faults to form. Though we do not have detailed topography across fault scarps on Dione, we can use their projected size on the camera plane to estimate their heights, assuming a reasonable surface slope. Starting with high resolution images of Dione obtained by the Cassini ISS, we marked points at the top to the bottom of each fault scarp to measure the fault’s projected displacement and its orientation along strike. Line and sample information for the measurements were then processed through ISIS to derive latitude/longitude information and pixel dimensions. We then calculate the three dimensional orientation of a vector running from the bottom to the top of the fault scarp, assuming a 45 degree angle with respect to the surface, and project this vector onto the spacecraft camera plane. This projected vector gives us a correction factor to estimate the actual vertical displacement of the fault scarp. This process was repeated many times for each fault, to show variations of displacement along the length of the fault. To compare each fault to its neighbors and see how strain was accommodated across a population of faults, we divided the faults into fault zones, and created new coordinate systems oriented along the central axis of each fault zone. We could then quantify the amount of fault overlap and add the displacement of overlapping faults to estimate the amount of strain accommodated in each zone. Faults in the southern portion of Padua have a strain of 0.031(+/-) 0.0097, central Padua exhibits a strain of .032(+/-) 0.012, and faults in northern Padua have a strain of 0.025(+/-) 0.0080. The western faults of Eurotas have a strain of 0.031(+/-) 0.011, while the eastern faults have a strain of 0.037(+/-) 0.025. Lastly, Clusium has a strain of 0.10 (+/-) 0.029. We also calculated the ratio of maximum fault displacement vs. the length of the faults, and we found this ratio to be 0.019 when drawing a trend line through all the faults that were analyzed. D/L measurements performed on two faults on Europa using stereo topography showed a value of .021 (Nimmo and Schenk 2006), the only other icy satellite where this ratio has been measured. In contrast, faults on Earth has a D/L ratio of about .1 and Mars has a D/L Ratio of about .01 (Schultz et al. 2006).

Tarlow, S.; Collins, G. C.

2010-12-01

158

Characterization of fault recovery through fault injection on FTMP  

NASA Technical Reports Server (NTRS)

The development of fault-injection procedures and statistical analysis techniques to characterize the fault recovery of fault-tolerant systems is described. Pin-level fault-injection was conducted on a fault-tolerant microprocessor computer in order to generate data to assess the utility of current fault-injection sampling methods. The validity of common reliability-modeling assumptions concerning the statistical distribution of recovery times is investigated. A multiple comparison analysis for detecting behavior variations, and a distribution fitting for determining the best fit for the data were conducted. It is observed that the detection behavior is not homogeneous across all data sets, and that none of the factors under experimental control can account for the observed groupings of behavior. It is determined that no single distribution fits all the data sets, and that stratified random sampling and statistically robust parameter-estimation techniques are required to characterize fault detection time.

Finelli, George B.

1987-01-01

159

An empirical comparison of software fault tolerance and fault elimination  

NASA Technical Reports Server (NTRS)

Reliability is an important concern in the development of software for modern systems. Some researchers have hypothesized that particular fault-handling approaches or techniques are so effective that other approaches or techniques are superfluous. The authors have performed a study that compares two major approaches to the improvement of software, software fault elimination and software fault tolerance, by examination of the fault detection obtained by five techniques: run-time assertions, multi-version voting, functional testing augmented by structural testing, code reading by stepwise abstraction, and static data-flow analysis. This study has focused on characterizing the sets of faults detected by the techniques and on characterizing the relationships between these sets of faults. The results of the study show that none of the techniques studied is necessarily redundant to any combination of the others. Further results reveal strengths and weakness in the fault detection by the techniques studied and suggest directions for future research.

Shimeall, Timothy J.; Leveson, Nancy G.

1991-01-01

160

Quantifying Anderson's fault types  

NASA Astrophysics Data System (ADS)

Anderson [1905] explained three basic types of faulting (normal, strike-slip, and reverse) in terms of the shape of the causative stress tensor and its orientation relative to the Earth's surface. Quantitative parameters can be defined which contain information about both shape and orientation [Célérier, 1995], thereby offering a way to distinguish fault-type domains on plots of regional stress fields and to quantify, for example, the degree of normal-faulting tendencies within strike-slip domains. This paper offers a geometrically motivated generalization of Angelier's [1979, 1984, 1990] shape parameters ? and ? to new quantities named A? and A?. In their simple forms, A? varies from 0 to 1 for normal, 1 to 2 for strike-slip, and 2 to 3 for reverse faulting, and A?/ranges from 0° to 60°, 60° to 120°, and 120° to 180°, respectively. After scaling, A? and A? agree to within 2% (or 1°), a difference of little practical significance, although A? has smoother analytical properties. A formulation distinguishing horizontal axes as well as the vertical axis is also possible, yielding an A? ranging from -3 to +3 and A? from -180° to +180°. The geometrically motivated derivation in three-dimensional stress space presented here may aid intuition and offers a natural link with traditional ways of plotting yield and failure criteria. Examples are given, based on models of Bird [1996] and Bird and Kong [1994], of the use of Anderson fault parameters A? and A? for visualizing tectonic regimes defined by regional stress fields.

Simpson, Robert W.

1997-08-01

161

Effect of surrounding fault on distributed fault of blind reverse fault in sedimentary basin - Uemachi Faults, Osaka Basin, Southwest Japan -  

NASA Astrophysics Data System (ADS)

Several large cities and metropolitan areas, such as Osaka and Kobe are located in the Osaka basin, which has been filled by the Pleistocene Osaka group and the later sediments. The basin is surrounded by E-W trending strike slip faults and N-S trending reverse faults. The N-S trending 42-km-long Uemachi faults traverse in the central part of the Osaka city. The various geological, geophysical surveys, such as seismic reflection, micro tremor, gravity surveys and deep boreholes, revealed the complex basement configuration along the Uemachi faults. The depth of the basement is shallow in the central part of the Osaka plain. The Uemachi faults are locates on the western side of the basement upland. In the central part of the Uemachi faults, the displacement decreases. The fault model of the Uemachi faults consists of the two parts, the north and south parts. The NE-SW trending branch faults, Suminoe and Sakuragawa flexures, are also recognized based on various surveys around the central part. Kusumoto et al. (2001) reported that surrounding faults enable to form the basement configuration without the Uemachi faults model based on a dislocation model. Inoue et al. (2011) performed various parameter studies for dislocation model and gravity changes based on simplified faults model, which were designed based on the distribution of the real faults. The model was consisted of 7 faults including the Uemachi faults. In this study, the Osaka-wan fault was considered for the dislocation model. The results show the basement configuration including NE-SW branch faults. The basement configuration differs from the subsurface structure derived from the investigation of abundance geotechnical borehole data around the central part of the Uemachi faults. The tectonic developing process including the erosion and sea level change are require to understanding the structure from the basement to the surface of the Uemachi Fault Zone. This research is partly funded by the Comprehensive Research on the Uemachi Fault Zone (in FY2010 and FY2011) by MEXT.

Inoue, N.

2012-12-01

162

An experiment in software fault elimination and fault tolerance  

SciTech Connect

Three primary approaches have been taken in developing methods to improve software reliability: fault avoidance, fault elimination and fault tolerance. This study investigates the error detection obtained by application of two of these approaches, fault tolerance and fault elimination, on a set of independently developed versions of a program. Different fault detection techniques following each approach are used to provide a broad exposure of each approach on the versions. The fault detection techniques chosen were multi-version voting, programmer-inserted run-time assertions, testing, code reading of uncommented code by stepwise abstraction and static data flow analysis. Voting and run-time assertions are most commonly associated with fault tolerance. Testing, code reading and static data flow analysis are most commonly associated with fault elimination. After application of the techniques following each approach, the errors detected and the circumstances of detection were analyzed as a means of characterizing the differences between the approaches. The results of this study provide insight on a series of research questions. The results demonstrate weaknesses in the fault tolerance approach and specifically in the multi-version voting method. In particular, the results demonstrate that voting of untested software may produce an insufficient improvement in the probability of producing a correct result to consider such use in systems where reliability is important. Voting is not to be a substitute for testing. Examination of the faults detected in this experiment show that the majority of faults were detected by only one technique. The results of this study suggest a series of questions for further research. For example, research is needed on how to broaden the classes of faults detected by each technique.

Shimeall, T.J.

1989-01-01

163

Randomness fault detection system  

NASA Technical Reports Server (NTRS)

A method and apparatus are provided for detecting a fault on a power line carrying a line parameter such as a load current. The apparatus monitors and analyzes the load current to obtain an energy value. The energy value is compared to a threshold value stored in a buffer. If the energy value is greater than the threshold value a counter is incremented. If the energy value is greater than a high value threshold or less than a low value threshold then a second counter is incremented. If the difference between two subsequent energy values is greater than a constant then a third counter is incremented. A fault signal is issued if the counter is greater than a counter limit value and either the second counter is greater than a second limit value or the third counter is greater than a third limit value.

Russell, B. Don (Inventor); Aucoin, B. Michael (Inventor); Benner, Carl L. (Inventor)

1996-01-01

164

Earthquakes and Fault Lines  

NSDL National Science Digital Library

The purpose of this activity is for students to find the locations of the fault lines in Utah and understand that fault lines are often earthquake zones. They will learn how often earthquakes are expected to occur, when Utah is due for another one, and where the next one is expected to occur. This meets the Utah Core Standard for fifth grade science: Standard 2: Students will understand that volcanoes, earthquakes, uplift, weathering, and erosion reshape Earth's surface. Objective 1,c: Explain the relationship between time and specific geological changes. Objective 2: Explain how volcanoes, earthquakes, and uplift affect Earth's surface. Situation You are from Montana, and your dad just got a new job in Northern Utah. Your family will have to move there. Your parents have heard that Utah has the potential for major earthquakes, and don?t know where to build your new house. They ...

Bennington, Miss

2010-04-26

165

Characterizing the Alpine Fault Strike Slip System Using a Novel Method for Analyzing GPS Data  

NASA Astrophysics Data System (ADS)

Plate motion across the South Island is dominated by right-lateral strike-slip (38-39 mm/yr total in the direction parallel to the Alpine Fault), with a small convergent component (8-10 mm/yr). The Alpine Fault is the most active fault in the region taking up 27×5 mm/yr in right-lateral strike-slip and ~10 mm/yr in dip-slip. It fails in large >=7 Mw earthquakes with recurrence time of 200-400 years and last ruptured around 1717. A significant component of the plate motion budget must occur on faults other than the Alpine Fault, but this is not fully accounted for in catalogues of known active faults. In the central part of the South Island, low slip rate active faults are not well-expressed due to the rapid erosion of the Southern Alps and deposition of these sediments onto the Canterbury plains; the devastating 2010 Darfield earthquake sequence occurred on such previously unknown faults. We apply a novel inversion technique (Dimitrova et al. 2012, 2013) to dense campaign GPS velocities in the region to solve for the vertical derivatives of horizontal stress (VDoHS) rates which are a substantially higher resolution expression of subsurface sources of ongoing deformation than the GPS velocities or GPS derived strain rates. Integrating the VDoHS rates gives us strain rates. Relationships between the VDoHS and strain rates allow us to calculate the variation in fault slip rate and locking depth for the identified faults; e.g., we estimate along fault variations for locking depth and slip rate for the Alpine Fault in the South Island in good agreement with previous estimates, and provide first estimates for those properties on the smaller, previously-uncharacterized faults which account for as much as 50% of the plate motion depending on location. For the first time, we note that the area between the Alpine Fault and the Main Divide of the Southern Alps is undergoing extensional areal strain, potentially indicative of gravitational collapse of the Southern Alps. The Arthur's Pass section of the Alpine Fault exhibits no shear component in the spatial derivatives of the VDoHS rates, in marked contrast to the Alpine Fault segments just northeast and southwest, suggesting that post-seismic deformation related to the 1994 Arthur's Pass earthquake is masking the signal from the Alpine Fault beneath. We characterize in detail the transfer of slip further north into the Marlborough Fault System, where we find much of the slip on the Alpine Fault passes onto the Kelly and Hope Faults, in accord with previous geological studies.

Haines, A. J.; Dimitrova, L. L.; Wallace, L. M.; Williams, C. A.

2013-12-01

166

The San Andreas Fault 'Supersite' (Invited)  

NASA Astrophysics Data System (ADS)

An expanded and permanent Supersite has been proposed to the Committee on Earth Observation Satellites (CEOS) for the San Andreas Fault system, based upon the successful initial Group on Earth Observations (GEO) Geohazard Supersite for the Los Angeles region from 2009-2013. As justification for the comprehensive San Andreas Supersite, consider the earthquake history of California, in particular the devastating M 7.8 San Francisco earthquake of 1906, which occurred along the San Andreas Fault, as did an earthquake of similar magnitude in 1857 in southern California. Los Angeles was only a small town then, but now the risk exposure has increased for both of California's megacities. Between the San Francisco and Los Angeles urban areas lies a section of the San Andreas Fault known to creep continually, so it has relatively less earthquake hazard. It used to be thought of as capable of stopping earthquakes entering it from either direction. Transitional behavior at either end of the creeping section is known to display a full range of seismic to aseismic slip events and accompanying seismicity and strain transient events. Because the occurrence of creep events is well documented by instrumental networks such as CISN and PBO, the San Andreas Supersite can be expected to be especially effective. A good baseline level of geodetic data regarding past events and strain accumulation and release exists. Many prior publications regarding the occurrence of geophysical phenomena along the San Andreas Fault system mean that in order to make novel contributions, state-of-the-art science will be required within this Supersite region. In more recent years, the 1989 Loma Prieta earthquake struck adjacent to the San Andreas Fault and caused the most damage along the western side of the San Francisco Bay Area. More recently, the concern has focused on the potential for future events along the Hayward Fault along the eastern side of San Francisco Bay. In Southern California, earthquakes struck in 1992 (Landers), 1994 (Northridge) and 1999 (Hector Mine) as well as the 2010 El Mayor - Cucapah (EM-C) earthquake (just south of the US-Mexico border). Of these four notable events, all produced extensive surface faulting except for the 1994 Northridge event, which was close to the Los Angeles urban area on a buried thrust fault. Northridge caused by far the most destruction, topping $20B (US) and resulting in 57 fatalities due to its location under an urban area. The Landers, Hector Mine and EM-C events occurred in desert areas away from major urban centers, and each proved to be a new and unique test-bed for making rapid progress in earthquake science and creative use of geodetic imagery. InSAR studies were linked to GPS deformation and mapping of surface ruptures and seismicity in a series of important papers about these earthquakes. The hazard in California remains extremely high, with tens of millions of people living in close proximity to the San Andreas Fault system as it runs past both San Francisco and Los Angeles. Dense in-situ networks of seismic and geodetic instruments are continually used for research and earthquake monitoring, as well as development of an earthquake early warning capability. Principles of peer review from funding agencies and open data availability will be observed for all data. For all of these reasons, the San Andreas Fault system is highly appropriate for consideration as a world-class permanent Supersite in the GEO framework.

Hudnut, K. W.

2013-12-01

167

Folds, Faults, and Mountains  

NSDL National Science Digital Library

This interactive Flash explores forces and processes that deform rocks by creating folds, faults, and mountain ranges. The overview covers topics such as stress, tension, deformation, strike, dip, folds and thrusts, and an interactive model allows users to model different processes related to these topics. This site provides diagrams, interactive animations, and supplementary information suitable for introductory level undergraduate physical geology or high school Earth science students.

Smoothstone; Company, Houghton M.

168

The temporal relationship between joints and faults  

NASA Astrophysics Data System (ADS)

Examples are presented of three temporal relationships between joints and faults: joints that pre-date faults; joints that are precursors to, or synchronous with, faults; and joints that post-date faults. Emphasis is placed on strike-slip faults in carbonate beds, but other examples are used. General rules are given for identifying the three temporal relationships between joints and faults. Joints that formed before faults can be dilated, sheared or affected by pressure solution during faulting, depending on their orientation in relation to the applied stress system. Faulted joints can preserve some original geometry of a joint pattern, with pinnate joints or veins commonly developing where faulted joints interact. Joints formed synchronously with faults reflect the same stress system that caused the faulting, and tend to increase in frequency toward faults. In contrast, joints that pre- or post-date faults tend not to increase in frequency towards the fault. Joints that post-date a fault may cut across or abut the fault and fault-related veins, without being displaced by the fault. They may also lack dilation near the fault, even if the fault has associated veins. Joints formed either syn- or post-faulting may curve into the fault, indicating stress perturbation around the fault. Different joint patterns may exist across the fault because of mechanical variations. Geometric features may therefore be used in the field to identify the temporal relationships between faults and joints, especially where early joints affect or control fault development, or where the distribution of late joints are influenced by faults.

Peacock, D. C. P.

2001-02-01

169

Fault tolerant control laws  

NASA Technical Reports Server (NTRS)

A systematic procedure for the synthesis of fault tolerant control laws to actuator failure has been presented. Two design methods were used to synthesize fault tolerant controllers: the conventional LQ design method and a direct feedback controller design method SANDY. The latter method is used primarily to streamline the full-state Q feedback design into a practical implementable output feedback controller structure. To achieve robustness to control actuator failure, the redundant surfaces are properly balanced according to their control effectiveness. A simple gain schedule based on the landing gear up/down logic involving only three gains was developed to handle three design flight conditions: Mach .25 and Mach .60 at 5000 ft and Mach .90 at 20,000 ft. The fault tolerant control law developed in this study provides good stability augmentation and performance for the relaxed static stability aircraft. The augmented aircraft responses are found to be invariant to the presence of a failure. Furthermore, single-loop stability margins of +6 dB in gain and +30 deg in phase were achieved along with -40 dB/decade rolloff at high frequency.

Ly, U. L.; Ho, J. K.

1986-01-01

170

Fault Analysis of Double Line Transmission System with STATCOM Controller Using Neuro-Wavelet Based Technique  

E-print Network

The STATCOM (Synchronous Static Compensator) based on voltage source converter (VSC) is used for voltage regulation in transmission and distribution systems. The STATCOM can rapidly supply dynamic VARs required during system faults for voltage support. The apparent impedance is influenced by the reactive power injected or absorbed by the STATCOM, which will result in the under reaching or over reaching of distance relay. This paper presents simulation results of the application of distance relays for the protection of transmission systems employing flexible alternating current transmission controllers such as STATCOM. The complete digital simulation of the Static synchronous Compensator within a transmission system is performed in the MATLAB/Simulink environment using the Power System Block set (PSB). This paper presents an efficient method based on wavelet transforms, fault detection, classification and location using ANN technique which is almost independent of fault impedance, fault distance and fault inception angle of transmission line fault currents with FACTS controllers.

R. Kameswara Rao; G. Ravi Kumar; Shaik Abdul Gafoor; S. S. Tulasi Ram

171

An empirical comparison of software fault tolerance and fault elimination  

Microsoft Academic Search

A large-scale experiment comparing software fault tolerance and software fault elimination as approaches to improving software reliability is described. Results are examined that apply to the appropriateness and underlying assumption of the two i.e., reducing standard testing procedures when using voting to achieve fault-tolerance in operational software and using voting in the testing process. Among other results, it was found

Timothy J. Shimeall; Nancy G. Leveson

1988-01-01

172

Fault tree analysis is widely used in industry for fault diagnosis. The diagnosis of incipient or `soft' faults is  

E-print Network

Fault tree analysis is widely used in industry for fault diagnosis. The diagnosis of incipient results based on a neural network approach. INTRODUCTION Fault tree analysis (FTA) and fault tree used in systems safety analysis for over 30 years. During this time the fault tree method has been used

Madden, Michael

173

This paper compares two fault injection techniques: scan chain implemented fault injection (SCIFI), i.e. fault  

E-print Network

Abstract This paper compares two fault injection techniques: scan chain implemented fault injection (SCIFI), i.e. fault injection in a physical system using built in test logic, and fault injection in a VHDL software simulation model of a system. The fault injections were used to evaluate the error

Karlsson, Johan

174

Rapid Prototyping  

NASA Technical Reports Server (NTRS)

Javelin, a Lone Peak Engineering Inc. Company has introduced the SteamRoller(TM) System as a commercial product. The system was designed by Javelin during a Phase II NASA funded small commercial product. The purpose of the invention was to allow automated-feed of flexible ceramic tapes to the Laminated Object Manufacturing rapid prototyping equipment. The ceramic material that Javelin was working with during the Phase II project is silicon nitride. This engineered ceramic material is of interest for space-based component.

1999-01-01

175

Interpretation of footwall (lowside) fault traps sealed by reverse faults and convergent wrench faults  

SciTech Connect

Lowside (footwall) closures sealed by reverse-slip faults and convergent strike-slip faults offer opportunities for significant field extension and new field prospects in basins deformed by contraction. The faults have reverse separation in cross section and transverse closure (in the direction of reservoir dip) is often provided by dip of beds away from the fault at structural upturns. The upturns are common and form at the edge of the footwall block as a consequence of block-edge folding, fault drag, and shortening transverse to fault strike. Effective fault seal and longitudinal closure (parallel to reservoir strike) are the most uncertain trap controls. Fault seal may be provided by the juxtaposition of older, less permeable rocks against the down-dropped reservoir or by impermeable material within the fault zone. Fault-zone barriers to fluid flow include shaly smear gouge, cataclastic gouge, mineral deposits, or asphalt or tar impregnation. Longitudinal closure is most commonly formed by a broad positive warp or bowing at the edge of the footwall block or by stratigraphic reservoir terminations. Secondary faults, intersections of primary block faults, and en echelon folds may also provide longitudinal closure. Prospects can range in importance from secondary extensions of existing highside closures to large traps unrelated to hanging-wall structure. The variety of geometries, relationships that provide transverse and longitudinal closure, and important geologic parameters that determine fault seal are illustrated with examples from oil fields in Sumatra and southern California. These fields can be used as models for the recognition and delineation of prospects in other basins. 16 figures.

Harding, T.P.; Tuminas, A.C.

1988-06-01

176

Overview of the Southern San Andreas Fault Model  

USGS Publications Warehouse

This appendix summarizes the data and methodology used to generate the source model for the southern San Andreas fault. It is organized into three sections, 1) a section by section review of the geological data in the format of past Working Groups, 2) an overview of the rupture model, and 3) a manuscript by Biasi and Weldon (in review Bulletin of the Seismological Society of America) that describes the correlation methodology that was used to help develop the ?geologic insight? model. The goal of the Biasi and Weldon methodology is to quantify the insight that went into developing all A faults; as such it is in concept consistent with all other A faults but applied in a more quantitative way. The most rapidly slipping fault and the only known source of M~8 earthquakes in southern California is the San Andreas fault. As such it plays a special role in the seismic hazard of California, and has received special attention in the current Working Group. The underlying philosophy of the current Working Group is to model the recurrence behavior of large, rapidly slipping faults like the San Andreas from observed data on the size, distribution and timing of past earthquakes with as few assumptions about underlying recurrence behavior as possible. In addition, we wish to carry the uncertainties in the data and the range of reasonable extrapolations from the data to the final model. To accomplish this for the Southern San Andreas fault we have developed an objective method to combine all of the observations of size, timing, and distribution of past earthquakes into a comprehensive set of earthquake scenarios that each represent a possible history of earthquakes for the past ~1400 years. The scenarios are then ranked according to their overall consistency with the data and then the frequencies of all of the ruptures permitted by the current Working Group?s segmentation model are calculated. We also present 30-yr conditional probabilities by segment and compare to previous results. A distinctive aspect of the current model is that the probability is higher at both ends of the fault and that the ends have a much greater fraction of smaller events. There is a significant difference in the likelihood of large (M 7.7-8.0) earthquakes along the fault from north to south, with large 1857-like events common on the northern half of the southern San Andreas fault but relatively few M 7.7-8.0 expected on the southern half.

Weldon, Ray J., II; Biasi, Glenn P.; Wills, Chris J.; Dawson, Timothy E.

2008-01-01

177

Fault-tolerant TCP mechanisms  

E-print Network

OF CONTENTS CHAPTER Page IV INTRODUCTION . RELATED WORK A. Replication Schemes 1. Active Replication/State Machine 2. Passive Replication/Primary-Backup Paradigm B. Group Communication . C. Fault-Tolerant Distributed Object Methodology D. Programming... and Virtual Synchrony. . . . . . FAULT- TOLERANT MECHANISMS A. Synchronization Using TCP Reassembly Queue 1. TCP Reassembly . 2. Modified TCP Reassembly 3. Various Schemes of Processing Incoming Segments B. Fault Detection, Fail-Over and Recovery 1...

Satapati, Suresh Kumar

2012-06-07

178

Compositional Temporal Fault Tree Analysis  

Microsoft Academic Search

HiP-HOPS (Hierarchically-Performed Hazard Origin and Propaga- tion Studies) is a recent technique that partly automates Fault Tree Analysis (FTA) by constructing fault trees from system topologies annotated with component-level failure specifications. HiP-HOPS has hitherto created only classical combinatorial fault trees that fail to capture the often significant temporal ordering of failure events. In this paper, we propose temporal extensions to

Martin Walker; Leonardo Bottaci; Yiannis Papadopoulos

2007-01-01

179

Polynomially Complete Fault Detection Problems  

Microsoft Academic Search

We look at several variations of the single fault detection problem for combinational logic circuits and show that deciding whether single faults are detectable by input-output (I\\/O) experiments is polynomially complete, i.e., there is a polynomial time algorithm to decide if these single faults are detectable if and only if there is a polynomial time algorithm for problems such as

Oscar H. Ibarra; Sartaj Sahni

1975-01-01

180

A survey of an introduction to fault diagnosis algorithms  

NASA Technical Reports Server (NTRS)

This report surveys the field of diagnosis and introduces some of the key algorithms and heuristics currently in use. Fault diagnosis is an important and a rapidly growing discipline. This is important in the design of self-repairable computers because the present diagnosis resolution of its fault-tolerant computer is limited to a functional unit or processor. Better resolution is necessary before failed units can become partially reuseable. The approach that holds the greatest promise is that of resident microdiagnostics; however, that presupposes a microprogrammable architecture for the computer being self-diagnosed. The presentation is tutorial and contains examples. An extensive bibliography of some 220 entries is included.

Mathur, F. P.

1972-01-01

181

Fault interaction near Hollister, California  

SciTech Connect

A numerical model is used to study fault stress slip near Hollister, California. The geometrically complex system of interacting faults, including the San Andreas, Calaveras, Sargent, and Busch faults, is approximated with a two-dimensional distribution of short planar fault segments in an elastic medium. The steady stress and slip rate are simulated by specifying frictional strength and stepping the remote stress ahead in time. The resulting computed fault stress is roughly proportional to the observed spatial density of small earthquakes, suggesting that the distinction between segments characterized by earthquakes and those with aseismic creep results, in part, from geometry. A nonsteady simulation is made by introducing, in addition, stress drops for individual moderate earthquakes. A close fit of observed creep with calculated slip on the Calaveras and San Andreas faults suggests that many changes in creep rate (averaged over several months) are caused by local moderate earthquakes. In particular, a 3-year creep lag preceding the August 6, 1979, Coyote Lake earthquake on the Calaveras fault seems to have been a direct result of the November 28, 1974, Thanksgiving Day earthquake on the Busch fault. Computed lags in slip rate preceding some other moderate earthquakes in the area are also due to earlier earthquakes. Although the response of the upper 1 km of the fault zone may cause some individual creep events and introduce delays in others, the long-term rate appears to reflect deep slip.

Mavko, G.M.

1982-09-10

182

Fault-Tree Compiler Program  

NASA Technical Reports Server (NTRS)

FTC, Fault-Tree Compiler program, is reliability-analysis software tool used to calculate probability of top event of fault tree. Five different types of gates allowed in fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N. High-level input language of FTC easy to understand and use. Program supports hierarchical fault-tree-definition feature simplifying process of description of tree and reduces execution time. Solution technique implemented in FORTRAN, and user interface in Pascal. Written to run on DEC VAX computer operating under VMS operating system.

Butler, Ricky W.; Martensen, Anna L.

1992-01-01

183

Neotectonic faulting in northern Norway; the Stuoragurra and Nordmannvikdalen postglacial faults  

Microsoft Academic Search

A systematic compilation and characterisation of many reports of neotectonic crustal deformation in Norway (both on local and regional scales) has identified two neotectonic faults in northern Norway. The Stuoragurra Fault is a large reverse fault in Finnmark County. The Nordmannvikdalen fault is a much smaller normal fault in Troms County. The Stuoragurra postglacial fault can be followed, in several

John F. Dehls; Odleiv Olesen; Lars Olsen; Lars Harald Blikra

2000-01-01

184

An Approach to Fault Modeling and Fault Seeding Using the Program Dependence Graph1  

E-print Network

fault seeder makes controlled fault transformations to the PDG for a C program, and generates C code from the transformed PDG. The current version of the fault seeder creates multiple faultAn Approach to Fault Modeling and Fault Seeding Using the Program Dependence Graph1 Mary Jean

Harrold, Mary Jean

185

Fault-tolerant Sensor Network based on Fault Evaluation Matrix and Compensation for Intermittent Observation  

E-print Network

Fault-tolerant Sensor Network based on Fault Evaluation Matrix and Compensation for Intermittent Observation Kazuya Kosugi, Shinichiro Tokumoto and Toru Namerikawa Abstract-- This paper deals with a fault for constructing a fault tolerant system. Specifically, we propose a fault-evaluation matrix for the fault

186

Fault Location Orion is the distribution company for the Canterbury region. In 2007, a Ground Fault  

E-print Network

Fault Location Orion is the distribution company for the Canterbury region. In 2007, a Ground Fault faults. This system operates by reducing the fault currents present during a fault, extinguishing and preventing arcing from occurring. Although this is greatly beneficial to the system, the reduction in fault

Hickman, Mark

187

Geophysical anomalies and segmentation of the Hayward Fault, San Andreas Fault System, Northern California, USA  

Microsoft Academic Search

The Hayward Fault, part of the San Andreas Fault System, extends for about 90 km and is regarded as one of the most hazardous faults in northern California. The Hayward Fault is predominantly a right-lateral strike-slip fault that forms the western boundary of the East Bay Hills with about 100 km of total offset along the fault zone. The Hayward

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

2003-01-01

188

On-line fault diagnosis of distribution substations using hybrid cause-effect network and fuzzy rule-based method  

Microsoft Academic Search

A correct and rapid inference is required for practical use of an online fault diagnosis in power substations. This paper proposes a novel approach for on-line fault section estimations and fault types identification using the hybrid cause-effect network\\/fuzzy rule-based method in distribution substations. A cause-effect network, which is well suited to parallel processing, represents the functions of protective relays and

Wen-Hui Chen; Chih-Wen Liu; Men-Shen Tsai

2000-01-01

189

Fault current limiter  

DOEpatents

A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

Darmann, Francis Anthony

2013-10-08

190

Perspective View, Garlock Fault  

NASA Technical Reports Server (NTRS)

California's Garlock Fault, marking the northwestern boundary of the Mojave Desert, lies at the foot of the mountains, running from the lower right to the top center of this image, which was created with data from NASA's shuttle Radar Topography Mission (SRTM), flown in February 2000. The data will be used by geologists studying fault dynamics and landforms resulting from active tectonics. These mountains are the southern end of the Sierra Nevada and the prominent canyon emerging at the lower right is Lone Tree canyon. In the distance, the San Gabriel Mountains cut across from the leftside of the image. At their base lies the San Andreas Fault which meets the Garlock Fault near the left edge at Tejon Pass. The dark linear feature running from lower right to upper left is State Highway 14 leading from the town of Mojave in the distance to Inyokern and the Owens Valley in the north. The lighter parallel lines are dirt roads related to power lines and the Los Angeles Aqueduct which run along the base of the mountains.

This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.

Size: Varies in a perspective view Location: 35.25 deg. North lat., 118.05 deg. West lon. Orientation: Looking southwest Original Data Resolution: SRTM and Landsat: 30 meters (99 feet) Date Acquired: February 16, 2000

2000-01-01

191

Dynamics of earthquake faults  

SciTech Connect

The authors present an overview of ongoing studies of the rich dynamical behavior of the uniform, deterministic Burridge-Knopoff model of an earthquake fault, discussing the model's behavior in the context of current seismology. The topics considered include: (1) basic properties of the model, such as the distinction between small and large events and the magnitude vs frequency distribution; (2) dynamics of individual events, including dynamical selection of rupture propagation speeds; (3) generalizations of the model to more realistic, higher-dimensional models; and (4) studies of predictability, in which artificial catalogs generated by the model are used to test and determine the limitations of pattern recognition algorithms used in seismology.

Carlson, J.M. (Department of Physics and Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)); Langer, J.S. (Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States)); Shaw, B.E. (Institute for Theoretical Physics, University of California, Santa Barbara, California 93106 (United States) Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York 10964 (United States))

1994-04-01

192

Origin of dilational normal faults and implications for fluid flow and mineralization  

NASA Astrophysics Data System (ADS)

Under conditions of low differential effective stress and minimum principal effective stress near zero or tensile, typical of the uppermost brittle crust, rocks fail in several modes and with variable failure angles. Under these conditions, mechanical stratigraphy exerts a significant influence on initial dip of normal faults, which results in zones of enhanced fault permeability. Less competent layers fail in shear mode along fractures that approximate the failure angle predicted by a standard rock mechanics analysis. Deformation of more competent layers, which is driven in part by interaction with the more rapidly deforming incompetent layers, produces a hybrid mode failure in which failure angles are smaller than in shear mode. Analyses of small-displacement (<1 m displacement) normal faults cutting Cretaceous carbonate strata in west Texas (USA) indicate that fault geometries resulting from this effect commonly display steep segments where the fault traverses more competent beds. Thus, normal faults are refracted through the mechanical stratigraphy. Displacement on these faults has caused dilation of steeper segments. Similar fault geometries in the North Pennine Orefield, England, host ore deposits along steep dilational fault segments. Dilatant segments along faults within carbonates of the Cretaceous-age Edwards Group near San Antonio, Texas (USA) localize groundwater flow and are consequently enlarged by dissolution to form important permeability and shallow groundwater infiltration pathways. Dilational normal faulting should be expected in mechanically layered strata that experience extensional deformation in the uppermost brittle crust. In addition to implications for groundwater flow and mineralization, dilational normal faulting may be a key factor in development of heterogenous and anisotropic permeability in oil and gas reservoirs where faulting developed at shallow depths.

Ferrill, D. A.; Morris, A. P.

2002-12-01

193

Central Asia Active Fault Database  

NASA Astrophysics Data System (ADS)

The ongoing collision of the Indian subcontinent with Asia controls active tectonics and seismicity in Central Asia. This motion is accommodated by faults that have historically caused devastating earthquakes and continue to pose serious threats to the population at risk. Despite international and regional efforts to assess seismic hazards in Central Asia, little attention has been given to development of a comprehensive database for active faults in the region. To address this issue and to better understand the distribution and level of seismic hazard in Central Asia, we are developing a publically available database for active faults of Central Asia (including but not limited to Afghanistan, Tajikistan, Kyrgyzstan, northern Pakistan and western China) using ArcGIS. The database is designed to allow users to store, map and query important fault parameters such as fault location, displacement history, rate of movement, and other data relevant to seismic hazard studies including fault trench locations, geochronology constraints, and seismic studies. Data sources integrated into the database include previously published maps and scientific investigations as well as strain rate measurements and historic and recent seismicity. In addition, high resolution Quickbird, Spot, and Aster imagery are used for selected features to locate and measure offset of landforms associated with Quaternary faulting. These features are individually digitized and linked to attribute tables that provide a description for each feature. Preliminary observations include inconsistent and sometimes inaccurate information for faults documented in different studies. For example, the Darvaz-Karakul fault which roughly defines the western margin of the Pamir, has been mapped with differences in location of up to 12 kilometers. The sense of motion for this fault ranges from unknown to thrust and strike-slip in three different studies despite documented left-lateral displacements of Holocene and late Pleistocene landforms observed near the fault trace.

Mohadjer, Solmaz; Ehlers, Todd A.; Kakar, Najibullah

2014-05-01

194

SFT: Scalable Fault Tolerance  

SciTech Connect

In this paper we will present a new technology that we are currently developing within the SFT: Scalable Fault Tolerance FastOS project which seeks to implement fault tolerance at the operating system level. Major design goals include dynamic reallocation of resources to allow continuing execution in the presence of hardware failures, very high scalability, high efficiency (low overhead), and transparency—requiring no changes to user applications. Our technology is based on a global coordination mechanism, that enforces transparent recovery lines in the system, and TICK, a lightweight, incremental checkpointing software architecture implemented as a Linux kernel module. TICK is completely user-transparent and does not require any changes to user code or system libraries; it is highly responsive: an interrupt, such as a timer interrupt, can trigger a checkpoint in as little as 2.5?s; and it supports incremental and full checkpoints with minimal overhead—less than 6% with full checkpointing to disk performed as frequently as once per minute.

Petrini, Fabrizio; Nieplocha, Jarek; Tipparaju, Vinod

2006-04-15

195

Colorado Regional Faults  

SciTech Connect

Citation Information: Originator: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Originator: Colorado Geological Survey (CGS) Publication Date: 2012 Title: Regional Faults Edition: First Publication Information: Publication Place: Earth Science & Observation Center, Cooperative Institute for Research in Environmental Science, University of Colorado, Boulder Publisher: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Description: This layer contains the regional faults of Colorado Spatial Domain: Extent: Top: 4543192.100000 m Left: 144385.020000 m Right: 754585.020000 m Bottom: 4094592.100000 m Contact Information: Contact Organization: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Contact Person: Khalid Hussein Address: CIRES, Ekeley Building Earth Science & Observation Center (ESOC) 216 UCB City: Boulder State: CO Postal Code: 80309-0216 Country: USA Contact Telephone: 303-492-6782 Spatial Reference Information: Coordinate System: Universal Transverse Mercator (UTM) WGS’1984 Zone 13N False Easting: 500000.00000000 False Northing: 0.00000000 Central Meridian: -105.00000000 Scale Factor: 0.99960000 Latitude of Origin: 0.00000000 Linear Unit: Meter Datum: World Geodetic System 1984 (WGS ’984) Prime Meridian: Greenwich Angular Unit: Degree Digital Form: Format Name: Shape file

Khalid Hussein

2012-02-01

196

Fault Models for Quantum Mechanical Switching Networks  

Microsoft Academic Search

The difference between faults and errors is that, unlike faults, errors can\\u000abe corrected using control codes. In classical test and verification one\\u000adevelops a test set separating a correct circuit from a circuit containing any\\u000aconsidered fault. Classical faults are modelled at the logical level by fault\\u000amodels that act on classical states. The stuck fault model, thought of

Jacob D. Biamonte; Jeff S. Allen; Marek A. Perkowski

2010-01-01

197

Development of a bridge fault extractor tool  

E-print Network

to process variations and the limitations of the patterning process. What is more important from a test and diagnosis viewpoint is ensuring that the more probable faults are on the fault list. ATPG will likely not target all possible realistic faults... to process variations and the limitations of the patterning process. What is more important from a test and diagnosis viewpoint is ensuring that the more probable faults are on the fault list. ATPG will likely not target all possible realistic faults...

Bhat, Nandan D.

2005-02-17

198

Detecting Faults in Computational Grids  

Microsoft Academic Search

In this paper we will first present a basic definition and a brief history of grid computing since its inception during the last decade. We will then look at a review of the most common faults occurring within the grid environment as identified by a survey of grid computing users. Two papers addressing fault detection are then reviewed for comparison.

Russ Wakefield

199

AFTP Fault Tree Analysis Program  

Microsoft Academic Search

Evaluation of the cut sets of large s-coherent and non-coherent fault trees presents a severe computational problem. The computer program, AFTP has been used to evaluate the important minimal cut and path sets of large fault trees containing many hundreds of gates. The computational advantages of a Boolean algebra, bottom-up approach are emphasised.

Richard A. Pullen

1984-01-01

200

Uncertainties in Fault Tree Analysis  

Microsoft Academic Search

Fault tree analysis is one kind of the probabilistic safety analysis method. After constructing a fault tree, many basic events which can happen theoretically have never occurred so far or have occurred so infrequently that their reasonable data are not available. However, the use of fuzzy probability can describe the failure probability and its uncertainty of each basic event ,

Yue-Lung Cheng

201

Surface Creep on California Faults  

NSDL National Science Digital Library

This site provides data from a number of creepmeters in California. A creepmeter is an instrument that monitors the slow surface displacement of an active fault. Its function is not to measure fault slip during earthquakes, but to record the slow aseismic slip between earthquakes.

Bilham, Roger; Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado

202

FOR AIRCRAFT ENGINE FAULT DIAGNOSTICS  

Microsoft Academic Search

Accurate and timely detection and diagnosis of aircraft engine fault is critical to the normal operation of engine\\/airplane and to maintain them in a healthy state. In engine fault diagnostics, engine gas path measurements, such as exhaust gas temperature (EGT), fuel flow (WF) and core speed (N2), etc. are frequently used. Some diagnostics models employ trend shift detection for these

Xiao Hu; Neil Eklund; Kai Goebel

203

Intelligent Fault Localization in Software  

Microsoft Academic Search

Thtis paper reports on two areas of research in softmare fault localization. We propose a conceptual model of software fault localization with roots in cognitive science. The model has both shallow and deep reasoning phases. It requires the programmer to activate complex knowledge bases and build internal models of the Buggy code and a correct representation. An architecture for an

Ilene Burnstein; Nitya Jani; Steve Mannina; Joe Tamsevicius; Michael Goldshteynl; Louis Lendif

1992-01-01

204

Active Diagnosis via AUC Maximization: An Efficient Approach for Multiple Fault Identification in Large Scale, Noisy Networks  

E-print Network

Active Diagnosis via AUC Maximization: An Efficient Approach for Multiple Fault Identification University of Texas Medical Branch, Galveston Abstract The problem of active diagnosis arises in sev- eral applications such as disease diagnosis, and fault diagnosis in computer networks, where the goal is to rapidly

Bhavnani, Suresh K.

205

Intelligent fault diagnosis of power transmission line; -.  

E-print Network

??This dissertation presents the application of recent intelligent newlinetechniques for fault diagnosis in electrical power transmission line Fault newlinesection identification classification and location are the… (more)

Malathi, V

2014-01-01

206

Modern glacial outwash sand along the Denali Fault: Thermochronological constraints on strike-slip fault and glacier interaction  

NASA Astrophysics Data System (ADS)

The interplay between tectonic and climatic processes on exhumation patterns is a fundamental question in current tectonic research. There has been a special focus on the affect of glacial processes on exhumation patterns in tectonically active orogens. Conclusions about exhumation extent related to late Cenozoic climatic forcing are often complicated by the possibility of movement along unknown ice-covered faults in glaciated mountain belts. In this study we investigate the interaction between glacial processes and the ice-covered Denali fault through detrital geochronology of modern glacier outwash sediments. The narrow high-relief Alaska Range provides a unique opportunity to examine the interaction of Pliocene-Quaternary glaciation with a known large-scale intercontinental strike-slip fault on long term exhumation patterns. Key attributes of the research area are a comprehensive bedrock thermochronology record of long-term rapid/deep exhumation (~24 Ma to present/~14 km), the orogen’s tectonic relationship with the ice covered Denali Fault, a preponderance of highly erosive surge-type glaciers along the Fault trace and a ~350 km transect of easily accessible sampling sites. By comparing U-Pb zircon emplacement ages (~70 Ma to ~38 Ma) and 40Ar/39Ar mica exhumation ages (~33 Ma to ~18 Ma) from bedrock samples with sub-glacial 40Ar/39Ar mica single grain fusion age distributions from glacial outwash sand we can differentiate between predicted cooling age patterns. We can distinguish between three different scenarios from the full data set: a) Outwash data slightly younger than bedrock data set-This would imply same trend as bedrock samples, where as biotite and muscovite samples get younger as you approach the Denali Fault in agreement with dip-slip on the Denali Fault is a significant contributor to topographic development in the region. b) Outwash data same or older then bedrock data set-This would imply structures splaying off the Denali Fault are predominately responsible for exhumation in the region. c) Outwash data significantly younger than bedrock data set-This would imply some other process is occurring-glacier/strike-slip fault exhumation feedback loop. Because of the geologically instantaneous lag time, weathering is limited on the detrital mica sample set. Step-heating of glacial outwash micas (biotite and muscovite) from the Black Rapids glacier have demonstrated little argon loss/alteration. In addition automation allows quick turn around on each glacial outwash sample. Thus, outwash mica ages can provide a unique data set to complement other previously used detrital thermochronometers (e.g. zircon fission track) to constrain sub-glacial exhumation histories.

Benowitz, J.; Layer, P. W.; O'Sullivan, P. B.; Vanlaningham, S.; Herreid, S. J.

2010-12-01

207

Fault-Tolerant Quantum Computation for Local Leakage Faults  

E-print Network

We provide a rigorous analysis of fault-tolerant quantum computation in the presence of local leakage faults. We show that one can systematically deal with leakage by using appropriate leakage-reduction units such as quantum teleportation. The leakage noise is described by a Hamiltonian and the noise is treated coherently, similar to general non-Markovian noise analyzed in Refs. quant-ph/0402104 and quant-ph/0504218. We describe ways to limit the use of leakage-reduction units while keeping the quantum circuits fault-tolerant and we also discuss how leakage reduction by teleportation is naturally achieved in measurement-based computation.

Panos Aliferis; Barbara M. Terhal

2005-11-07

208

Comparison of Cenozoic Faulting at the Savannah River Site to Fault Characteristics of the Atlantic Coast Fault Province: Implications for Fault Capability  

SciTech Connect

This study compares the faulting observed on the Savannah River Site and vicinity with the faults of the Atlantic Coastal Fault Province and concludes that both sets of faults exhibit the same general characteristics and are closely associated. Based on the strength of this association it is concluded that the faults observed on the Savannah River Site and vicinity are in fact part of the Atlantic Coastal Fault Province. Inclusion in this group means that the historical precedent established by decades of previous studies on the seismic hazard potential for the Atlantic Coastal Fault Province is relevant to faulting at the Savannah River Site. That is, since these faults are genetically related the conclusion of ''not capable'' reached in past evaluations applies.In addition, this study establishes a set of criteria by which individual faults may be evaluated in order to assess their inclusion in the Atlantic Coast Fault Province and the related association of the ''not capable'' conclusion.

Cumbest, R.J.

2000-11-14

209

Improving Multiple Fault Diagnosability using Possible Conflicts  

NASA Technical Reports Server (NTRS)

Multiple fault diagnosis is a difficult problem for dynamic systems. Due to fault masking, compensation, and relative time of fault occurrence, multiple faults can manifest in many different ways as observable fault signature sequences. This decreases diagnosability of multiple faults, and therefore leads to a loss in effectiveness of the fault isolation step. We develop a qualitative, event-based, multiple fault isolation framework, and derive several notions of multiple fault diagnosability. We show that using Possible Conflicts, a model decomposition technique that decouples faults from residuals, we can significantly improve the diagnosability of multiple faults compared to an approach using a single global model. We demonstrate these concepts and provide results using a multi-tank system as a case study.

Daigle, Matthew J.; Bregon, Anibal; Biswas, Gautam; Koutsoukos, Xenofon; Pulido, Belarmino

2012-01-01

210

Arc fault detection system  

DOEpatents

An arc fault detection system for use on ungrounded or high-resistance-grounded power distribution systems is provided which can be retrofitted outside electrical switchboard circuits having limited space constraints. The system includes a differential current relay that senses a current differential between current flowing from secondary windings located in a current transformer coupled to a power supply side of a switchboard, and a total current induced in secondary windings coupled to a load side of the switchboard. When such a current differential is experienced, a current travels through a operating coil of the differential current relay, which in turn opens an upstream circuit breaker located between the switchboard and a power supply to remove the supply of power to the switchboard. 1 fig.

Jha, K.N.

1999-05-18

211

Crustal collapse and the formation of synthetic normal faults  

NASA Astrophysics Data System (ADS)

Geologic mapping and seismic imaging of regions of continental extension often shows normal faults dipping in the same direction within a subregion or corridor. For example Stewart (1978) describes zones across broad parts of the Basin and Range Province of Western North America with synthetic faulting. Patton et al. (1994) maps out corridors across the well studied Gulf of Suez which are characterized by major normal faults that dip in the same direction. We investigate mechanical conditions that can lead to such packages of synthetic normal faults during continental extension using both analytic and numerical approaches. Two-dimensional numerical simulations treat lithospheric extension with strain weakening in the brittle upper crust and allow for spontaneous development of localized shear zones (i.e. model faults). Here we describe model results for cases with laterally uniform crust overlying mantle lithosphere. In the interest of simplicity we ignore thermal advection and diffusion of heat that would lead to lateral variations in crustal viscosity. The model viscosity decreases exponentially with depth. The model fault pattern in the upper crust depends strongly on the viscous behavior of the warmer lower crust. In cases where the viscosity decreases slowly with depth, a system of antithetic faults develops over the entire width of the model domain. The faults form and grow simultaneously and can result in a horst and graben pattern. Multiple synthetic faults can develop when the brittle upper crust essentially collapses into the widening hole caused by extensional crustal thinning. The synthetic faults develop sequentially as the region of crustal thinning widens. We see this pattern of similar dips developing only when the force required for extension of the viscous transition region between the brittle upper crust and the weak lower crust is small compared to the force related to crustal thinning. In the context of this simple model set-up, this occurs when the viscosity decreases very rapidly with depth. Also, the low viscosity lower crust cannot flow into the region of crustal thinning so fast that lateral crustal thickness contrasts do not develop.

Buck, R.; Nagel, T.; Lavier, L.

2003-04-01

212

Fluid transport by solitary waves along growing faults. A field example from the South Eugene Island Basin, Gulf of Mexico  

NASA Astrophysics Data System (ADS)

The Red Fault system is one of the main growth faults found in the South Eugene Island Basin, a salt withdrawal minibasin located offshore Louisiana, in the Gulf of Mexico. This fault system corresponds to a lateral boundary between fluid overpressured compartments. In addition, there is a set of observations indicating that the Red Fault system exhibits rapid episodic migration of fluids. This fault represents an example of preferential pathway for the upward episodic migration of overpressured hydrocarbons from deep, heavily pressured, compartments on time scales of years. The migrations of fluids into active growing faults could take the form of propagating surges (solitary waves) that propagate upward along the fault planes in a wave-like manner at km/yr. Solitary waves represent a very efficient mechanism for the upward transport of fluids along growth faults in sedimentary basins generating its own permeability. In addition, this mechanism is compatible with the fact that the fault plane is observed to sustain a static pore fluid pressure difference between its two sides. The propagation of solitary waves in active growth faults appears as a fundamental mechanism to understand the nature of upward fast migration of fluids along active growth faults in compartimentalized sedimentary basins.

Revil, A.; Cathles, L. M.

2002-09-01

213

Hayward Fault rate constraints at Berkeley: Evaluation of the 335-meter Strawberry Creek offset  

NASA Astrophysics Data System (ADS)

At UC Berkeley the active channel of Strawberry Creek is offset 335 meters by the Hayward fault and two abandoned channels of Strawberry Creek are laterally offset 580 and 730 meters. These relationships record the displacement of the northern Hayward fault at Berkeley over a period of tens of millennia. The Strawberry Creek site has a similar geometry to the central San Andreas fault's Wallace Creek site, which arguably provides the best geological evidence of "millennial" fault kinematics in California (Sieh and Jahns, 1984). Slip rate determinations are an essential component of overall hazard evaluation for the Hayward fault, and this site is ripe to disclose a long-term form of this parameter, to contrast with geodetic and other geological rate evidence. Large offsets at the site may lower uncertainty in the rate equation relative to younger sites, as the affect of stream abandonment age, generally the greatest source of rate uncertainty, is greatly reduced. This is helpful here because it more-than-offsets uncertainties resulting from piercing projections to the fault. Strawberry Creek and its ancestral channels suggest west-side-up vertical deformation across the Hayward fault at this location. The development of the vertical deformation parameter will complement ongoing geodetic measurements, particularly InSAR, and motivate testing of other geological constraints. Up-to-the-west motion across the Hayward fault at Berkeley has important implications for the partitioning of strain and kinematics of the northern Hayward fault, and may explain anomalous up-on-the-west landforms elsewhere along the fault. For example, geological features of the western Berkeley Hills are consistent with rapid and recent uplift to the west of the fault. On the basis of a preliminary analysis of the offset channels of Strawberry Creek, up-to-the-west uplift is about 0.5mm/yr across the Hayward fault at Berkeley. If this is in fact the long-term rate, the 150 m height of the Hills to the northwest of the Strawberry Creek site was produced during the past about 300,000 years by a significant dip- slip (thrust) component of Hayward fault motion. Rapid and recent uplift of some portions of the East Bay Hills has important implications for fault geometries and slope stability, and should strongly influence the investigation fault hazards in areas that are more complexly deformed.

Williams, P. L.

2007-12-01

214

Exploring Transient Fault Slip Behaviors and ``Earthquake'' Distributions Using Discrete Element Models  

NASA Astrophysics Data System (ADS)

Discrete Element Method (DEM) simulations have been used to analyze the frictional properties and deformation along faults, including the effects of fault gouge, grain shape and gouge evolution, rate and state friction, and 3-dimensional configurations. With some exceptions, the transient behavior of fault slip in this type of model has not been explored in detail, although DEM simulations allow both large- and small-scale details of the fault system to be monitored throughout the model evolution. Fundamental questions about fault slip processes can be examined in detail. For example, do modeled slip events correspond to natural earthquakes? Do parameters such as slip distance, rupture size, and stress drop agree with observations from earthquake catalogs? Do they exhibit well-known frequency-magnitude relationships, such as Omori and Gutenberg-Richter laws? Are other slip behaviors (e.g. slow slip) evident? We examine these questions in a series of simple model experiments. We construct 2-dimensional infinite-length faults (1 km long with periodic lateral boundaries), analogs for crustal-scale strike-slip faults. We can adjust the fault friction, material properties of the blocks on either side of the fault, clamping pressure, and loading rate. Fault displacement is induced by moving the far-field boundaries to produce right lateral shearing conditions. Slip localizes naturally onto the pre-defined fault, which undergoes episodes of sticking and intermittent rapid slip. In this configuration, we can identify “earthquakes”, which are used to create catalogs for statistical analysis. We can also examine the fault rupture properties and processes. We compare our results to real world observations, and query the simulations further to address pressing questions about the range of fault slip behaviors. The models show regular, but locally heterogeneous, stress cycling on the fault, where stress builds with strain and is released in a series rapid slip events. Repeating events are also evident, denoting rupture of persistent asperities that evolve only gradually with time. Stress accumulation and release on the fault is a function almost entirely of asperity size and distributions. The slip events show a remarkable variability in size and duration.

Fournier, T.; Morgan, J. K.

2010-12-01

215

Seismicity and Stress Change Along the Central Philippine Fault Zone  

NASA Astrophysics Data System (ADS)

Recent findings showed that the Philippine fault zone (PFZ) has a creeping section, a transition zone and a locked portion in its central portion. This part of the PFZ is comprised of the Guinyangan, Masbate, northern Leyte and southern Leyte faults. In this study, an attempt is taken to have a closer look on the seismic pattern and relationship between the creep events, moderate quakes and major events along in Guinyangan, Masbate, and northern Leyte, respectively based on the recent available seismic data and field surveys. Dislocation along a fault that involves no rapid release of energy in a seismic event is called creep. Creep was identified along the central PFZ in early 1990s using GPS records. On the other hand, moderate quakes are earthquakes with magnitude range of M5.5~M7. In central PFZ, moderate quakes were recognized to occur along the transition zone through an event in early 2003 that was accompanied by a large ground rupture. Although moderate events have usually a calculated fault. This portion is considered locked and the locus of major quakes in the past. South of the Guinyangan fault is the Masbate fault. A very interesting event occurred in this fault in 2003 along the Masbate fault, a transition zone. South of this portion is the northern Leyte fault which is considered undergoing a creep activity. After the 2003 event, the Guinyangan fault was anticipated to experience some changes in local stress field. However, the temporal and spatial plots of seismicity indicate a west-northwestward propagation of seismic activity along the Sibuyan fault. Sibuyan fault is an offshore fault traversing the Sibuyan Sea and probably into Taal area and/or branches out into the southern part of Marinduque island. Considering the amount of data available and the peculiar seismic activity along the central PFZ, we try to examine the seismicity and determine if a particular seismic pattern is discernable in this region and correlating them to possible regional and local stress change in a specific portion of the PFZ. Considering the importance of the results of this study and in view of the presence of major cities and towns in southern Luzon, the Sibuyan and Guinyangan faults need more attention for seismic and crustal deformation studies. Concerning the disaster mitigation and preparedness in the southern Luzon regions, finding from such researches would be an important input for local stress change research that could reveal the probability of local earthquake occurrence. Keeping in mind that the San Andreas fault has almost the same features, a comparison would be undertaken to note any similarities or differences between the two structures.

Besana, G. M.; Ando, M.; Ikuta, R.; Daligdig, J. A.; Panol, M. D.; Ikeda, A.; Nakamura, T.

2005-12-01

216

Continuous permeability measurements record healing inside the Wenchuan earthquake fault zone.  

PubMed

Permeability controls fluid flow in fault zones and is a proxy for rock damage after an earthquake. We used the tidal response of water level in a deep borehole to track permeability for 18 months in the damage zone of the causative fault of the 2008 moment magnitude 7.9 Wenchuan earthquake. The unusually high measured hydraulic diffusivity of 2.4 × 10(-2) square meters per second implies a major role for water circulation in the fault zone. For most of the observation period, the permeability decreased rapidly as the fault healed. The trend was interrupted by abrupt permeability increases attributable to shaking from remote earthquakes. These direct measurements of the fault zone reveal a process of punctuated recovery as healing and damage interact in the aftermath of a major earthquake. PMID:23812711

Xue, Lian; Li, Hai-Bing; Brodsky, Emily E; Xu, Zhi-Qing; Kano, Yasuyuki; Wang, Huan; Mori, James J; Si, Jia-Liang; Pei, Jun-Ling; Zhang, Wei; Yang, Guang; Sun, Zhi-Ming; Huang, Yao

2013-06-28

217

Paleoseismicity of the North American-Caribbean plate boundary (Septentrional fault), Dominican Republic  

USGS Publications Warehouse

The Septentrional fault zone, the major North American-Caribbean plate-boundary fault in Hispaniola, is a likely source of large earthquakes in the Dominican Republic. An excavation into a Holocene alluvial fan deposited across the fault in the central Cibao Valley, Dominican Republic, provides evidence that it has been at least 430 yr and probably more than 740 yr since the last ground-rupturing earthquake along this segment of the fault. On the basis of these data and published estimates of the plate-tectonic slip rate, it is proposed that the Septentrional fault is a source of high seismic potential in the densely populated and rapidly developing Cibao Valley in the northern Dominican Republic. -Authors

Prentice, C. S.; Mann, P.; Taylor, F. W.; Burr, G.; Valastro, S.

1993-01-01

218

Boullier The fault zone geology 1 Fault zone geology: lessons from drilling through the Nojima and 1  

E-print Network

Boullier The fault zone geology 1 Fault zone geology: lessons from drilling through the Nojima and 1 Chelungpu faults 2 3 Anne-Marie Boullier 4 active faults with the aim of 11 learning about the geology of the fault

Paris-Sud XI, Université de

219

Granular packings and fault zones  

PubMed

The failure of a two-dimensional packing of elastic grains is analyzed using a numerical model. The packing fails through formation of shear bands or faults. During failure there is a separation of the system into two grain-packing states. In a shear band, local "rotating bearings" are spontaneously formed. The bearing state is favored in a shear band because it has a low stiffness against shearing. The "seismic activity" distribution in the packing has the same characteristics as that of the earthquake distribution in tectonic faults. The directions of the principal stresses in a bearing are reminiscent of those found at the San Andreas Fault. PMID:11017335

Astrom; Herrmann; Timonen

2000-01-24

220

Fault-Tolerant Quantum Walks  

E-print Network

Quantum walks are expected to serve important modelling and algorithmic applications in many areas of science and mathematics. Although quantum walks have been successfully implemented physically in recent times, no major efforts have been made to combat the error associated with these physical implementations in a fault-tolerant manner. In this paper, we propose a systematic method to implement fault-tolerant quantum walks in discrete time on arbitrarily complex graphs, using quantum states encoded with the Steane code and a set of universal fault tolerant matrix operations.

S. D. Freedman; Y. H. Tong; J. B. Wang

2014-08-06

221

Kalman Predictive Redundancy System for Fault Tolerance of Safety-critical Systems  

Microsoft Academic Search

The dependence of intelligent vehicles on electronic devices is rapidly increasing the concern over fault tolerance due to safety issues. For example, an x-by-wire system, such as electromechanical brake system in which rigid mechanical components are replaced with dynamically configurable electronic elements, should be fault-tolerant because a critical failure could arise without warning. Therefore, in order to guarantee the reliability

Kyung Chang Lee; Man Ho Kim; Suk Lee

2010-01-01

222

Flash Heating and Fault Zone Evolution  

NASA Astrophysics Data System (ADS)

Accurate descriptions of strength evolution are required in predictive models of fault-zone behavior during earthquakes. At low sliding rates, frictional resistance between fault rocks is much higher than the shear stress that is typically inferred to be present during earthquakes. Laboratory experiments confirm that the friction coefficient drops at high sliding rates, and there are also suggestions that strengthening, possibly related to an increase in the area of viscous melt patches, may occur after this initial weakening stage. Most weakening mechanisms that have been proposed do not predict such strengthening, which may exert an important control on the thickness of the zones over which shear is accommodated during earthquakes. We propose a micro-mechanical model of flash heating that describes how shear resistance evolves at the asperity scale as a result of distributed deformation over a weak layer that grows during the brief lifetime of each asperity contact. Beyond a threshold weakening velocity, our model predicts that friction should decrease with slip rate since higher sliding speeds cause the weak layer to thicken more rapidly. A comparison with published experimental data from a range of mineral systems shows good agreement with the model predictions when two dimensionless fitting parameters are chosen appropriately. At higher sliding rates and/or elevated temperatures, our model predicts that the frictional rate dependence should transition from velocity weakening to become velocity strengthening because decreases in the contact lifetime with slip rate cause the average asperity strength to increase. Combining this frictional constitutive behavior with a description of the thermal pressurization of pore fluids, we predict the evolution of shear-zone thickness, temperature, and pore pressure during a model earthquake along a mature fault.

Chen, J.; Rempel, A. W.

2012-12-01

223

Using Fault Model Enforcement to Improve Availability  

E-print Network

it transforms faults not factored into the initial design into faults that the system was designed to tolerateUsing Fault Model Enforcement to Improve Availability Kiran Nagaraja, Ricardo Bianchini, Richard P that it is impractical to try to tolerate all (or even a significant fraction of) fault types in these systems. We argue

224

Using Fault Model Enforcement to Improve Availability  

E-print Network

it transforms faults not factored into the initial design into faults that the system was designed to tolerateUsing Fault Model Enforcement to Improve Availability Kiran Nagaraja, Ricardo Bianchini, Richard P to try to tolerate all (or even a significant fraction of) fault types in these systems. We argue instead

Martin, Richard P.

225

Diesel Engine Fault Diagnosis and Classification  

Microsoft Academic Search

Vibration signal of diesel engine fault is nonstationary and nonlinear. It is very difficult to analyze. Distinguishing diesel faults and classifying them is more difficult. In this paper, we use a new method 'Wigner Trispectrum (WT)' to describe the characteristics of vibration signals got from diesel engine. WT of signals can characterize each fault. Then WT of signals as fault

Shi Xiaochun; Hu Hongying

2006-01-01

226

Formal Concept Analysis applied to Fault Localization  

E-print Network

Formal Concept Analysis applied to Fault Localization Peggy Cellier IRISA, Campus Bealieu, 35042] in order to improve the fault localization. Formal Concept Analysis (FCA) has already been used for several Syntaxic Tree (AST) to improve fault localization, it gives a evaluation plan. 2. FAULT LOCALIZATION

Ferré, Sébastien

227

Seismic Fault Rheology and Earthquake Dynamics  

E-print Network

5 Seismic Fault Rheology and Earthquake Dynamics JAMES R. RICE1 and MASSIMO COCCO2 1Department Workshop on The Dynamics of Fault Zones, spe- cifically on the subtopic "Rheology of Fault Rocks and Their Surroundings," we addressed critical research issues for understanding the seismic response of fault zones

228

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

229

Fault Current Constrained Decentralized Optimal Power Flow Incorporating Superconducting Fault Current Limiter (SFCL)  

Microsoft Academic Search

The addition of new generation capacity increases the fault current levels in power systems. New generation and transmission capacity additions can be limited by the fault current constraints in power systems. The superconducting fault current limiter (SFCL) has great potential as a special protection device to limit the fault current in the event of a fault in power systems. Installations

Guk-Hyun Moon; Young-Min Wi; Kisung Lee; Sung-Kwan Joo

2011-01-01

230

Monitoring and Diagnosis of Multiple Incipient Faults Using Fault Tree Induction  

E-print Network

synthesis (FTS) and fault tree analysis (FTA). FTS involves the construction of fault trees, and typicallyMonitoring and Diagnosis of Multiple Incipient Faults Using Fault Tree Induction Michael G. M algorithm for induction of fault trees. It learns from an examples database comprising sensor recordings

Madden, Michael

231

A Fault Prediction Approach for Process Plants using Fault Tree Analysis in Sensor Malfunction  

Microsoft Academic Search

In this paper, a fault prediction approach for process plants using fault tree analysis is presented in the presence of no or false information of certain sensor. The fault propagation model is constructed by causal relationships from fault tree analysis (FTA). Knowledge about system failure, which is obtained from the fault propagation model, is represented as abnormality patterns in process

Zongxiao Yang; Xiaobo Yuan; Zhiqiang Feng; Kazuhiko Suzuki; Akira Inoue

2006-01-01

232

A Framework for Optimal Fault-Tolerant Control Synthesis: Maximize Pre-Fault while  

E-print Network

1 A Framework for Optimal Fault-Tolerant Control Synthesis: Maximize Pre-Fault while Minimize Post-Fault State University, Ames, Iowa 50011 Abstract--In an earlier work, we introduced a framework for fault existence. In this paper, we introduce the synthesis of an optimal fault- tolerant supervisory controller

Kumar, Ratnesh

233

Fault Tolerant Control with Additive Compensation for Faults in an Automotive Damper  

E-print Network

Fault Tolerant Control with Additive Compensation for Faults in an Automotive Damper Juan C. Tud: sebastien.varrier@gipsa-lab.fr Abstract--A novel Fault-Tolerant Controller is proposed for an automotive mechanism used to accommodate actuator faults. The compensation mechanism is based on a robust fault

Paris-Sud XI, Université de

234

Fault-Trajectory Approach for Fault Diagnosis on Analog Circuits Carlos Eduardo Savioli,  

E-print Network

Fault-Trajectory Approach for Fault Diagnosis on Analog Circuits Carlos Eduardo Savioli, Claudio C Mesquita@coe.ufrj.br Abstract This issue discusses the fault-trajectory approach suitability for fault on this concept for ATPG for diagnosing faults on analog networks. Such method relies on evolutionary techniques

Paris-Sud XI, Université de

235

Fault classification and fault signature production for rolling element bearings in electric machines  

Microsoft Academic Search

Most condition monitoring techniques for rolling element bearings are designed to detect the four characteristic fault frequencies. This has lead to the common practice of categorizing bearing faults according to fault location (i.e., inner race, outer race, ball, or cage fault). While the ability to detect the four characteristic fault frequencies is necessary, this approach neglects another important class of

Jason R. Stack; Thomas G. Habetler; Ronald G. Harley

2004-01-01

236

The fault-tree compiler  

NASA Technical Reports Server (NTRS)

The Fault Tree Compiler Program is a new reliability tool used to predict the top event probability for a fault tree. Five different gate types are allowed in the fault tree: AND, OR, EXCLUSIVE OR, INVERT, and M OF N gates. The high level input language is easy to understand and use when describing the system tree. In addition, the use of the hierarchical fault tree capability can simplify the tree description and decrease program execution time. The current solution technique provides an answer precise (within the limits of double precision floating point arithmetic) to the five digits in the answer. The user may vary one failure rate or failure probability over a range of values and plot the results for sensitivity analyses. The solution technique is implemented in FORTRAN; the remaining program code is implemented in Pascal. The program is written to run on a Digital Corporation VAX with the VMS operation system.

Martensen, Anna L.; Butler, Ricky W.

1987-01-01

237

Fault Trace: Marin County, California  

NSDL National Science Digital Library

This photograph shows the trace of a fault (in trench phase) as it passes beneath a barn. The trace developed during the April 18, 1906 San Francisco Earthquake. The location is the Skinner Ranch, near Olema, Marin County, California.

238

Slip Rates on young faults  

NSDL National Science Digital Library

Students use measured ages and offset of quaternary surfaces to determine vertical slip rates of a young fault. Students then must determine if vertical slip rates have varied significantly through time.

Huerta, Audrey

239

Automatic Fault Extraction at Mid-Ocean Ridges: Effects of Bathymetry Resolution and Extraction Method  

NASA Astrophysics Data System (ADS)

High-angle normal faults at mid-ocean ridges are important indicators of the processes driving oceanic crust formation. Fault size and distribution are currently either estimated in the field or scarp outlines are painstakingly digitized by hand following a cruise. Some attempts have been made to automate this process using techniques from the fields of geomorphometry and image analysis, such as slope gradient and curvature thresholding and wavelet filtering. However, little assessment of the accuracy of these techniques has been made. Additionally, these techniques require manual threshold selection and thus cannot be equally applied to areas with different length scales of deformation. This study presents a fully-automatic method of fault extraction consisting of two major steps: fault identification and error removal. Fault scarps are initially extracted using slope gradient thresholding, profile curvature thresholding and the Canny edge detection algorithm. The extracted set of faults is then refined by removing small noise objects, eliminating other steep seafloor features with an aspect ratio threshold, and finally by focusing on a single fault population using an azimuth threshold. Terrain thresholds are automatically determined from digital bathymetric model (DBM) gradient and curvature histograms using the Jenks natural breaks algorithm, and error removal thresholds are standardized based on DBM resolution. DBMs at a variety of resolutions (1 m - 150 m pixels) and at a variety of spreading locations are used to test the three methods. Results show that automatic extraction accuracy varies widely and is affected most by the linearity of fault lines and the smoothness of fault upper and lower boundaries rather than by resolution or extraction method. Assessed visually, the gradient method gives better results for large, smooth, linear faults located far from the axis. The curvature method gives better results for small, sharp, complex faults located adjacent to the axis. The best overall results are achieved by the edge detection method, which maximizes fault line continuity and detects a large number of faults overall. The main disadvantage of this method is that it produces fault lines rather than polygons. These initial results are promising and suggest that with further work automatic fault extraction can be sufficiently optimized to be useful for rapid initial analysis of fault patterns.

Schnur, S.; Escartin, J.; Purves, R. S.; Frueh-Green, G. L.; Soule, S. A.

2011-12-01

240

Weakening inside incipient thrust fault  

NASA Astrophysics Data System (ADS)

In fold-and-thrust belts, shortening is mainly accommodated by thrust faults that nucleate along décollement levels. Geological and geophysical evidence suggests that these faults might be weak because of a combination of processes such as pressure-solution, phyllosilicates reorientation and delamination, and fluid pressurization. In this study we aim to decipher the processes and the kinetics responsible for weakening of tectonic décollements. We studied the Millaris thrust (Southern Pyrenees): a fault representative of a décollement in its incipient stage. This fault accommodated a total shortening of about 30 meters and is constituted by a 10m thick, intensively foliated phyllonite developed inside a homogeneous marly unit. Detailed chemical and mineralogical analyses have been carried out to characterize the mineralogical change, the chemical transfers and volume change in the fault zone compared to non-deformed parent sediments. We also carried out microstructural analysis on natural and experimentally deformed rocks. Illite and chlorite are the main hydrous minerals. Inside fault zone, illite minerals are oriented along the schistosity whereas chlorite coats the shear surfaces. Mass balance calculations demonstrated a volume loss of up to 50% for calcite inside fault zone (and therefore a relative increase of phyllosilicates contents) because of calcite pressure solution mechanisms. We performed friction experiments in a biaxial deformation apparatus using intact rocks sheared in the in-situ geometry from the Millaris fault and its host sediments. We imposed a range of normal stresses (10 to 50 MPa), sliding velocity steps (3-100 ?m/s) and slide-hold slide sequences (3 to 1000 s hold) under saturated conditions. Mechanical results demonstrate that both fault rocks and parent sediments are weaker than average geological materials (friction ?<<0.6) and have velocity-strengthening behavior because of the presence of phyllosilicate horizons. Fault rocks are remarkably weaker (?<0.3) than host marls (?> 0.35). Additionally, fault zone rocks do not show frictional healing, further supporting a non-seismic behavior and prolonged weakness. This study quantitatively demonstrates how tectonic detachments localize in incompetent formations and become readily weak, even after experiencing very small displacements.

Lacroix, B.; Tesei, T.; Collettini, C.; Oliot, E.

2013-12-01

241

Fault Tree Analysis: A Bibliography  

NASA Technical Reports Server (NTRS)

Fault tree analysis is a top-down approach to the identification of process hazards. It is as one of the best methods for systematically identifying an graphically displaying the many ways some things can go wrong. This bibliography references 266 documents in the NASA STI Database that contain the major concepts. fault tree analysis, risk an probability theory, in the basic index or major subject terms. An abstract is included with most citations, followed by the applicable subject terms.

2000-01-01

242

Tutorial: Advanced fault tree applications using HARP  

NASA Technical Reports Server (NTRS)

Reliability analysis of fault tolerant computer systems for critical applications is complicated by several factors. These modeling difficulties are discussed and dynamic fault tree modeling techniques for handling them are described and demonstrated. Several advanced fault tolerant computer systems are described, and fault tree models for their analysis are presented. HARP (Hybrid Automated Reliability Predictor) is a software package developed at Duke University and NASA Langley Research Center that is capable of solving the fault tree models presented.

Dugan, Joanne Bechta; Bavuso, Salvatore J.; Boyd, Mark A.

1993-01-01

243

A comparison of bridging fault simulation methods  

Microsoft Academic Search

This study provides bridging fault simulation data obtained from the AMD-K6 microprocessor. It shows that: (1) high stuck-at fault coverage (99.5%) implies high bridging fault coverage; (2) coverage of a bridging fault by both wired-AND and wired-OR behavior does not guarantee detection of that fault when compared against a more accurate (transistor-level simulation) modeling method. A set of netname pairs

R. Scott Fetherston; Imtiaz P. Shaik; Siyad C. Ma

1999-01-01

244

Nonlinear Network Dynamics on Earthquake Fault Systems  

SciTech Connect

Earthquake faults occur in interacting networks having emergent space-time modes of behavior not displayed by isolated faults. Using simulations of the major faults in southern California, we find that the physics depends on the elastic interactions among the faults defined by network topology, as well as on the nonlinear physics of stress dissipation arising from friction on the faults. Our results have broad applications to other leaky threshold systems such as integrate-and-fire neural networks.

Rundle, Paul B.; Rundle, John B.; Tiampo, Kristy F.; Sa Martins, Jorge S.; McGinnis, Seth; Klein, W.

2001-10-01

245

Ground penetrating radar imaging of active faults across the offshore-onshore boundary of the northern Gulf of Aqaba, Jordan  

NASA Astrophysics Data System (ADS)

The city of Aqaba is situated at the northern end of Gulf of Aqaba along the southern part of the Dead Sea Transform (DST) which is the main source of seismic activity in the region. A ground penetrating radar (GPR) survey was carried out Aqaba under the MERC M25-004 Project that seeks to map the active faults submerged in the northern gulf that lie immediately offshore and the faults that lie onshore beneath the rapidly developing cities of Aqaba and Eilat. Approximately 3000 m of GPR lines were collected in Aqaba with a 400 MHz and 100 MHz monostatic antennas. The maximum depth of penetration was with approximately 10 meter. The GPR survey conducted in Aqaba reveals several different kinds of anomalies and discontinuities. In order to enhance our interpration of the GPR anomalies, we collected several GPR lines across several locations in the city where faults, fractures, and channels have been mapped in trench exposures. Analysis of the anomalies and discontinuities in GPR cross section (radagram) can be interpreted as a set of shallow fractures and faults within various lithologic changes. All the detected faults located by GPR survey are shallow less than 10 m depth and have vertical small displacement within late Quaternary sediments. The GPR anomalies appear to align along three NE-trending fault zones in the city of Aqaba. These zones, that we call the Ayla fault, the West Aqaba fault, and the Aqaba fault zone, appear to be on land extensions of faults that have been imaged offshore in the Gulf of Aqaba as part of our recent marine geophysical survey. This study indicates that there are more active faults within the region than previously mapped. Studying the late Quaternary sediments would provide a way to characterize the seismic hazard potential of faults. The GPR inferred faults seem to be an extension of the marine seismic inferred fault.

Abueladas, Abdel-Rahman; Al-Zoubi, Abdallah; Niemi, Tina; Akawi, Emad; Alruzouq, Rami; Ben-Avraham, Zvi; Hartman, Gal; Tiber, Gideon

2010-05-01

246

Passive fault current limiting device  

DOEpatents

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment. 6 figs.

Evans, D.J.; Cha, Y.S.

1999-04-06

247

Passive fault current limiting device  

DOEpatents

A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

Evans, Daniel J. (Wheeling, IL); Cha, Yung S. (Darien, IL)

1999-01-01

248

Software Fault Tolerance: A Tutorial  

NASA Technical Reports Server (NTRS)

Because of our present inability to produce error-free software, software fault tolerance is and will continue to be an important consideration in software systems. The root cause of software design errors is the complexity of the systems. Compounding the problems in building correct software is the difficulty in assessing the correctness of software for highly complex systems. After a brief overview of the software development processes, we note how hard-to-detect design faults are likely to be introduced during development and how software faults tend to be state-dependent and activated by particular input sequences. Although component reliability is an important quality measure for system level analysis, software reliability is hard to characterize and the use of post-verification reliability estimates remains a controversial issue. For some applications software safety is more important than reliability, and fault tolerance techniques used in those applications are aimed at preventing catastrophes. Single version software fault tolerance techniques discussed include system structuring and closure, atomic actions, inline fault detection, exception handling, and others. Multiversion techniques are based on the assumption that software built differently should fail differently and thus, if one of the redundant versions fails, it is expected that at least one of the other versions will provide an acceptable output. Recovery blocks, N-version programming, and other multiversion techniques are reviewed.

Torres-Pomales, Wilfredo

2000-01-01

249

Gas permeability evolution of cataclasite and fault gouge in triaxial compression and implications for changes in fault-zone permeability structure through the earthquake cycle  

NASA Astrophysics Data System (ADS)

We report the results of permeability measurements of fault gouge and tonalitic cataclasite from the fault zone of the Median Tectonic Line, Ohshika, central Japan, carried out during triaxial compression tests. The experiments revealed marked effects of deformation on the permeability of the specimens. Permeability of fault gouge decreases rapidly by about two orders of magnitude during initial loading and continues to decrease slowly during further inelastic deformation. The drop in permeability during initial loading is much smaller for cataclasite than for gouge, followed by abrupt increase upon failure, and the overall change in permeability correlates well with change in volumetric strain, i.e., initial, nearly elastic contraction followed by dilatancy upon the initiation of inelastic deformation towards specimen failure. If cemented cataclasite suffers deformation prior to or during an earthquake, a cataclasite zone may change into a conduit for fluid flow. Fault gouge zones, however, are unlikely to switch to very permeable zones upon the initiation of fault slip. Thus, overall permeability structure of a fault may change abruptly prior to or during earthquakes and during the interseismic period. Fault gouge and cataclasite have internal angles of friction of about 36° and 45°, respectively, as is typical for brittle rocks.

Uehara, Shin-ichi; Shimamoto, Toshihiko

2004-01-01

250

Internal structure of the Kern Canyon Fault, California: a deeply exhumed strike-slip fault  

E-print Network

Deformation and mineral alteration adjacent to a 2 km long segment of the Kern Canyon fault near Lake Isabella, California are studied to characterize the internal structure of the fault zone and to understand the development of fault structure...

Neal, Leslie Ann

2012-06-07

251

Monitoring fault zone environments with correlations of earthquake waveforms  

NASA Astrophysics Data System (ADS)

We develop a new technique for monitoring temporal changes in fault zone environments based on cross-correlation of earthquake waveforms recorded by pairs of stations. The method is applied to waveforms of ˜10 000 earthquakes observed during 100 d around the 1999 M 7.1 Duzce mainshock by a station located in the core damage zone of the North Anatolian Fault and a nearby station. To overcome clock problems, the correlation functions are realigned on a dominant peak. Consequently, the analysis focuses on measurements of coherency rather than traveltimes, and is associated with correlation coefficient of groups of events with a reference wavelet. Examination of coherency in different frequency bands reveals clear changes at a narrow band centred around 0.8 Hz. The results show a rapid drop of ˜1-2 per cent of the coherency at the time of the Duzce event followed by gradual recovery with several prominent oscillations over 4 d. The observed changes likely reflect evolution of permeability and fluid motion in the core damage zone of the North Anatolian Fault. Compared to noise correlation processing, our analysis of earthquake waveform correlation (i) benefits from high level of coherence with short duration recorded signals, (ii) has considerably finer temporal sampling of fault dynamics after mainshocks than is possible with noise correlation, (iii) uses the coherence level to track property variations, which may be more robust than traveltime fluctuations in the coda of noise correlations. Studies utilizing both earthquake and noise waveforms at multiple pairs of stations across fault damage zones can improve significantly the understanding of fault zone processes.

Roux, Philippe; Ben-Zion, Yehuda

2014-02-01

252

Fault Analysis in Solar Photovoltaic Arrays  

NASA Astrophysics Data System (ADS)

Fault analysis in solar photovoltaic (PV) arrays is a fundamental task to increase reliability, efficiency and safety in PV systems. Conventional fault protection methods usually add fuses or circuit breakers in series with PV components. But these protection devices are only able to clear faults and isolate faulty circuits if they carry a large fault current. However, this research shows that faults in PV arrays may not be cleared by fuses under some fault scenarios, due to the current-limiting nature and non-linear output characteristics of PV arrays. First, this thesis introduces new simulation and analytic models that are suitable for fault analysis in PV arrays. Based on the simulation environment, this thesis studies a variety of typical faults in PV arrays, such as ground faults, line-line faults, and mismatch faults. The effect of a maximum power point tracker on fault current is discussed and shown to, at times, prevent the fault current protection devices to trip. A small-scale experimental PV benchmark system has been developed in Northeastern University to further validate the simulation conclusions. Additionally, this thesis examines two types of unique faults found in a PV array that have not been studied in the literature. One is a fault that occurs under low irradiance condition. The other is a fault evolution in a PV array during night-to-day transition. Our simulation and experimental results show that overcurrent protection devices are unable to clear the fault under "low irradiance" and "night-to-day transition". However, the overcurrent protection devices may work properly when the same PV fault occurs in daylight. As a result, a fault under "low irradiance" and "night-to-day transition" might be hidden in the PV array and become a potential hazard for system efficiency and reliability.

Zhao, Ye

253

Quantifying the Growth History of an Ancient Border Fault System, and the Role of Normal Fault Growth on Sedimentation During Basin Formation: a Case Study from the Late Cambrian Owen Conglomerate, West Coast Range, western Tasmania, Australia  

NASA Astrophysics Data System (ADS)

The stratigraphic and depositional architecture of evolving extensional basins is principally controlled by normal fault growth through the generation of accommodation space. The history of border fault systems therefore controls the evolution of internal drainage patterns and basin facies distributions. Despite recent advances in the understanding of present-day normal fault growth, quantifying the effect of normal fault evolution on the architecture of ancient sedimentary basins has been largely obscured by post-rift deformation and erosion. The Late Cambrian Owen Conglomerate along the West Coast Range of western Tasmania, Australia, includes thick fluvial sandstone and marine turbidite sequences, as well as fluvial and marine conglomerates. The accumulation of this formation provides excellent insights into the rift-fill history of an ancient extensional basin, due to rugged, glaciated topography and exceptional outcrops, and the typically overfilled nature of the basin, which preserves the fault displacement history. Structural traverses have delineated the geometry of the extensional fault system active during deposition of the Owen Conglomerate. The fault system comprises a segmented array of border faults with variable along-strike polarity. Minimum displacements were calculated from present-day stratigraphic thicknesses, and define a roughly symmetric displacement-length profile that resembles that of a single, isolated fault, with maximum displacement (Dmax) located at the centre of the fault array, and decreasing displacement toward the distal segments. Displacement along the fault system, however, indicates a varied growth history through time. Isolated faulting (Stage 1) occurred during the early stages of rifting, when small fault segments grew in isolation. Stage 1 faults exhibit a Dmax at the centre of each individual segment. Rapid propagation of fault segments to maximum strike length occurred early in the basin history, with only limited interaction and feedback between individual segments. Continued growth faulting (Stage 2) resulted in migration of the locus of maximum displacement as individual segments began to interact and link. Eventual linkage of fault segments (Stage 3) occurred during the final stages of rifting, where the overall system exhibits a characteristic, through-going, displacement-length profile. Integration of lithofacies distributions, isopach maps and palaeocurrent data with the structural dataset shows that the stratigraphic architecture is strongly coupled with the development of the border fault system, and offers a high resolution model for fault development. While the generation of accommodation space adjacent to footwall scarps facilitated the development of a hanging-wall, dip-slope fluvial catchment and axial-through drainage networks, tectonic subsidence also provided a crucial trigger for the onset of isolated marine sedimentation where accommodation space generated by the localised accumulation of displacement on individual segments outpaced sediment supply.

Noll, C. A.; Hall, M.

2003-12-01

254

Rapid prototyping of rapid prototyping machines  

E-print Network

Rapid prototyping tools empower individuals to create almost anything. Unfortunately, these tools are still far too expensive for personal ownership. The do-it-yourself community has responded with a slew of home-made rapid ...

Moyer, Ilan Ellison

2008-01-01

255

Critical fault patterns determination in fault-tolerant computer systems  

NASA Technical Reports Server (NTRS)

The method proposed tries to enumerate all the critical fault-patterns (successive occurrences of failures) without analyzing every single possible fault. The conditions for the system to be operating in a given mode can be expressed in terms of the static states. Thus, one can find all the system states that correspond to a given critical mode of operation. The next step consists in analyzing the fault-detection mechanisms, the diagnosis algorithm and the process of switch control. From them, one can find all the possible system configurations that can result from a failure occurrence. Thus, one can list all the characteristics, with respect to detection, diagnosis, and switch control, that failures must have to constitute critical fault-patterns. Such an enumeration of the critical fault-patterns can be directly used to evaluate the overall system tolerance to failures. Present research is focused on how to efficiently make use of these system-level characteristics to enumerate all the failures that verify these characteristics.

Mccluskey, E. J.; Losq, J.

1978-01-01

256

Fault Management Guiding Principles  

NASA Technical Reports Server (NTRS)

Regardless of the mission type: deep space or low Earth orbit, robotic or human spaceflight, Fault Management (FM) is a critical aspect of NASA space missions. As the complexity of space missions grows, the complexity of supporting FM systems increase in turn. Data on recent NASA missions show that development of FM capabilities is a common driver for significant cost overruns late in the project development cycle. Efforts to understand the drivers behind these cost overruns, spearheaded by NASA's Science Mission Directorate (SMD), indicate that they are primarily caused by the growing complexity of FM systems and the lack of maturity of FM as an engineering discipline. NASA can and does develop FM systems that effectively protect mission functionality and assets. The cost growth results from a lack of FM planning and emphasis by project management, as well the maturity of FM as an engineering discipline, which lags behind the maturity of other engineering disciplines. As a step towards controlling the cost growth associated with FM development, SMD has commissioned a multi-institution team to develop a practitioner's handbook representing best practices for the end-to-end processes involved in engineering FM systems. While currently concentrating primarily on FM for science missions, the expectation is that this handbook will grow into a NASA-wide handbook, serving as a companion to the NASA Systems Engineering Handbook. This paper presents a snapshot of the principles that have been identified to guide FM development from cradle to grave. The principles range from considerations for integrating FM into the project and SE organizational structure, the relationship between FM designs and mission risk, and the use of the various tools of FM (e.g., redundancy) to meet the FM goal of protecting mission functionality and assets.

Newhouse, Marilyn E.; Friberg, Kenneth H.; Fesq, Lorraine; Barley, Bryan

2011-01-01

257

Quantifying Morphologic Changes in a Low Gradient River Crossing Southeast Louisiana Fault Zones  

NASA Astrophysics Data System (ADS)

This study investigates the signature of faulting in low gradient, alluvial rivers crossing the Baton Rouge fault zone (BRFZ) and Denham Springs-Scotlandville fault zone (DSSFZ), which encompass a set of East-West striking normal faults in southeast Louisiana. These faults exhibit surface expressions associated with up to a few meters of vertical displacement of Late Pleistocene sediments, but little is known about their activity during the Holocene. Our study aims to quantify geomorphic changes in a number of rivers that cross these fault zones and to use these changes to gain insight into the history of faulting in the region. We hypothesize that fault movement will be evident in patterns of river sinuosity, slope, and width to depth ratio. We focus on four subparallel channels of various discharges that cross either or both the BRFZ and the DSSFZ. Information on local fault scarp heights and channel reaches are extracted by GIS analysis of the LA LiDAR 5 m DEM, as well as flow modeling using the HEC-RAS software program. On the Tickfaw River, we conducted field surveys using differential GPS to record contemporary water surface slopes and channel location. Historic channel features on the Tickfaw are characterized using a series of aerial photographs dating back to 1952. Over the past 50 years, the Tickfaw River has shortened its course through the study area significantly (~4.9%) by means of meander cutoffs. Since 1952, sinuosity (P) has decreased in all of the Tickfaw channel reaches that cross fault segments. Currently, the sinuosity is extremely low (average P = 1.14) where the river crosses the DSSFZ and slightly higher where the river crosses the BRFZ (average P = 1.9). We use the LiDAR data to quantify offset on the faults that the river crosses. These values will be compared with the average lateral migration rate of the river in order to better understand the time scales over which both processes operate. If the faults appear to have little morphologic impact on the river, it is likely that that fluvial migration rates are rapid enough to erase any signature of the accumulated throw from the faults. With continued analysis, our goal is to develop a reliable method for using alluvial rivers to help unravel the history of fault systems in low gradient landscapes, with possible applications for detecting regions vulnerable to fault-related subsidence.

Fischer, G.; Gasparini, N. M.; Dawers, N. H.

2011-12-01

258

Seismic slip propagation along a fault in the Shimanto accretionary prism detected by vitrinite reflectance studies  

NASA Astrophysics Data System (ADS)

Quantitative assessment of heat generation along faults during fault movement is of primary importance in understanding the dynamics of earthquakes. Last several years localized heat anomaly in a fault zone due to rapid seismic sliding has been detected by various analyses of fault zone materials, such as ferromagnetic resonance signal (Fukuchi et al., 2005), trace elements and isotopes (e.g., Ishikawa et al., 2008) and mineralogical change of clay (e.g., Hirono et al., 2008) and vitrinite reflectance (O'Hara, 2004). Here we report a heat anomaly found in a fault zone in the Shimanto accretionary complex by vitrinite reflectance measurements. Mature faults in nature mostly experience multiple seismic events, resulting in integrated heat anomaly. Thus, in addition to vitrinite reflectance measurements across natural faults, we performed high-velocity friction experiments on a mixture of quartz and vitrinite grains to evaluate how multiple rapid-slip events affect vitrinite reflectance in a fault zone. A localized heat anomaly is found in one of fault zones which are developed within a mélange unit in the Cretaceous Shimanto belt, SW Japan. A principle slip zone with thickness of ~5 mm forms within cataclastic damage zone with thickness of ~3 m. The slip zone is mainly composed of well-foliated clay minerals. Host rocks are characterized by a block-in-matrix texture: aligned sandstone and chert blocks embedded in mudstone matrix. We measured vitrinite reflectance across the fault zone by the same method as reported in Sakaguchi et al., (2011). The measurement reveals that the principle slip zone underwent localized temperature of more than 220°C, while background temperature of both damage zone and host rocks is ~170°C. Since fault motion along most active faults occurs seismological, that inevitably generates frictional heat, the localized heat anomaly is possibly caused by the rapid seismic slip. In order to evaluate the change in vitrinite reflectance by coseismic sliding, we conducted friction experiments on a mixture of 90 wt% quartz and 10 wt% vitrinite at slip rates of 1.3 mm/s and 1.3 m/s, normal stress of 1.0 MPa and displacement of 15 m under anoxic, nitrogen atmosphere. A series of slide-hold-slide tests are also performed to reproduce multiple seismic-slip events. Our preliminary observation of recovered specimens indicated that significant heat anomaly, especially at shear localized zone in the simulated gouge zone, can be detected by vitrinite reflectance measurement. Detailed results will be reported in our presentation.

Kitamura, M.; Mukoyoshi, H.; Hirose, T.

2011-12-01

259

Fault zone connectivity: slip rates on faults in the san francisco bay area, california.  

PubMed

The slip rate of a fault segment is related to the length of the fault zone of which it is part. In turn, the slip rate of a fault zone is related to its connectivity with adjoining or contiguous fault zones. The observed variation in slip rate on fault segments in the San Francisco Bay area in California is consistent with connectivity between the Hayward, Calaveras, and San Andreas fault zones. Slip rates on the southern Hayward fault taper northward from a maximum of more than 10 millimeters per year and are sensitive to the active length of the Maacama fault. PMID:17835127

Bilham, R; Bodin, P

1992-10-01

260

Istanbul Earthquake Early Warning and Rapid Response System  

Microsoft Academic Search

As part of the preparations for the future earthquake in Istanbul a Rapid Response and Early Warning system in the metropolitan area is in operation. For the Early Warning system ten strong motion stations were installed as close as possible to the fault zone. Continuous on-line data from these stations via digital radio modem provide early warning for potentially disastrous

M. O. Erdik; Y. Fahjan; O. Ozel; H. Alcik; M. Aydin; M. Gul

2003-01-01

261

Anisotropy of permeability in faulted porous sandstones  

NASA Astrophysics Data System (ADS)

Studies of fault rock permeabilities advance the understanding of fluid migration patterns around faults and contribute to predictions of fault stability. In this study a new model is proposed combining brittle deformation structures formed during faulting, with fluid flow through pores. It assesses the impact of faulting on the permeability anisotropy of porous sandstone, hypothesising that the formation of fault related micro-scale deformation structures will alter the host rock porosity organisation and create new permeability pathways. Core plugs and thin sections were sampled around a normal fault and oriented with respect to the fault plane. Anisotropy of permeability was determined in three orientations to the fault plane at ambient and confining pressures. Results show that permeabilities measured parallel to fault dip were up to 10 times higher than along fault strike permeability. Analysis of corresponding thin sections shows elongate pores oriented at a low angle to the maximum principal palaeo-stress (?1) and parallel to fault dip, indicating that permeability anisotropy is produced by grain scale deformation mechanisms associated with faulting. Using a soil mechanics 'void cell model' this study shows how elongate pores could be produced in faulted porous sandstone by compaction and reorganisation of grains through shearing and cataclasis.

Farrell, N. J. C.; Healy, D.; Taylor, C. W.

2014-06-01

262

Matching pursuit of an adaptive impulse dictionary for bearing fault diagnosis  

NASA Astrophysics Data System (ADS)

The sparse decomposition based on matching pursuit is an adaptive sparse expression of the signals. An adaptive matching pursuit algorithm that uses an impulse dictionary is introduced in this article for rolling bearing vibration signal processing and fault diagnosis. First, a new dictionary model is established according to the characteristics and mechanism of rolling bearing faults. The new model incorporates the rotational speed of the bearing, the dimensions of the bearing and the bearing fault status, among other parameters. The model can simulate the impulse experienced by the bearing at different bearing fault levels. A simulation experiment suggests that a new impulse dictionary used in a matching pursuit algorithm combined with a genetic algorithm has a more accurate effect on bearing fault diagnosis than using a traditional impulse dictionary. However, those two methods have some weak points, namely, poor stability, rapidity and controllability. Each key parameter in the dictionary model and its influence on the analysis results are systematically studied, and the impulse location is determined as the primary model parameter. The adaptive impulse dictionary is established by changing characteristic parameters progressively. The dictionary built by this method has a lower redundancy and a higher relevance between each dictionary atom and the analyzed vibration signal. The matching pursuit algorithm of an adaptive impulse dictionary is adopted to analyze the simulated signals. The results indicate that the characteristic fault components could be accurately extracted from the noisy simulation fault signals by this algorithm, and the result exhibited a higher efficiency in addition to an improved stability, rapidity and controllability when compared with a matching pursuit approach that was based on a genetic algorithm. We experimentally analyze the early-stage fault signals and composite fault signals of the bearing. The results further demonstrate the effectiveness and superiority of the matching pursuit algorithm that uses the adaptive impulse dictionary. Finally, this algorithm is applied to the analysis of engineering data, and good results are achieved.

Cui, Lingli; Wang, Jing; Lee, Seungchul

2014-05-01

263

Software reliability through fault-avoidance and fault-tolerance  

NASA Technical Reports Server (NTRS)

Twenty independently developed but functionally equivalent software versions were used to investigate and compare empirically some properties of N-version programming, Recovery Block, and Consensus Recovery Block, using the majority and consensus voting algorithms. This was also compared with another hybrid fault-tolerant scheme called Acceptance Voting, using dynamic versions of consensus and majority voting. Consensus voting provides adaptation of the voting strategy to varying component reliability, failure correlation, and output space characteristics. Since failure correlation among versions effectively reduces the cardinality of the space in which the voter make decisions, consensus voting is usually preferable to simple majority voting in any fault-tolerant system. When versions have considerably different reliabilities, the version with the best reliability will perform better than any of the fault-tolerant techniques.

Vouk, Mladen A.; Mcallister, David F.

1991-01-01

264

Faulted archaeological relics at Hierapolis (Pamukkale), Turkey  

NASA Astrophysics Data System (ADS)

The former Roman city of Hierapolis (modern Pamukkale), within the Büyük Menderes valley, contains an abundance of faulted architectural relics related to damaging earthquakes that have occurred since at least 60 A.D. Faulted relics include: (1) a Roman fresh-water channel; (2) a mid-Roman relief carved into a fault plane; (3) Roman and Byzantine walls offset across the Hierapolis normal fault zone; (4) the walls of a late Byzantine fort offset more than once across a fissure/fault; and (5) numerous displaced wall-like Roman and post-Roman petrified water channels. In addition to these faulted relics, numerous monuments display tilted and toppled walls; maximum damage generally being adjacent to the Hierapolis fault zone which passes through the centre of the city. Many relics are also partly covered by faulting-related travertine deposits. Analysis of the faulted relics indicates: (1) Hierapolis and its immediate surroundings are cut by two active normal fault zones; (2) the NNW-trending Hierapolis fault zone, formerly thought to be a sinistral strike-slip fault, is a small normal fault zone; (3) there has been about 1.5 m of normal slip on the Pamukkale range-front fault since mid-Roman times; (4) an opening direction across the weakly expressed Hierapolis fault zone can be inferred by matching formerly contiguous piercing points on the relic that are now on either side of the fault trace; (5) where a fault passes through a narrow rigid architectural relic, its trace is generally refracted so that it is oriented at roughly right angles to the long axis of the relic; and (6) some major dilated cracks cutting relics reflect the locations of underlying faults.

Hancock, P. L.; Altunel, E.

1997-09-01

265

The detection of high impedance faults using random fault behavior  

E-print Network

and with random intensity. The new algorithm presented attempts to utilize this random behavior as well as time to discriminate the pres- ence of high impedance arcing faults from normal system operations which may also generate a, high frequency current signal... overcurrent setting or fuse rating. This scenario would correspond to a feeder which is possibly heavily loaded during the day and lightly loaded at night with the fault occurring at night. The proposed A-system detector also has an enable signal generated...

Carswell, Patrick Wayne

2012-06-07

266

Heat flow and energetics of the San Andreas fault zone.  

USGS Publications Warehouse

Approximately 100 heat flow measurements in the San Andreas fault zone indicate 1) there is no evidence for local frictional heating of the main fault trace at any latitude over a 1000-km length from Cape Mendocino to San Bernardino, 2) average heat flow is high (ca.2 HFU, ca.80 mW m-2) throughout the 550-km segment of the Coast Ranges that encloses the San Andreas fault zone in central California; this broad anomaly falls off rapidly toward the Great Valley to the east, and over a 200-km distance toward the Mendocino Triple Junction to the northwest. As others have pointed out, a local conductive heat flow anomaly would be detectable unless the frictional resistance allocated to heat production on the main trace were less than 100 bars. Frictional work allocated to surface energy of new fractures is probably unimportant, and hydrologic convection is not likely to invalidate the conduction assumption, since the heat discharge by thermal springs near the fault is negligible. -Authors

Lachenbruch, A. H.; Sass, J. H.

1980-01-01

267

Transient Faults in Computer Systems  

NASA Technical Reports Server (NTRS)

A powerful technique particularly appropriate for the detection of errors caused by transient faults in computer systems was developed. The technique can be implemented in either software or hardware; the research conducted thus far primarily considered software implementations. The error detection technique developed has the distinct advantage of having provably complete coverage of all errors caused by transient faults that affect the output produced by the execution of a program. In other words, the technique does not have to be tuned to a particular error model to enhance error coverage. Also, the correctness of the technique can be formally verified. The technique uses time and software redundancy. The foundation for an effective, low-overhead, software-based certification trail approach to real-time error detection resulting from transient fault phenomena was developed.

Masson, Gerald M.

1993-01-01

268

Fault testing quantum switching circuits  

E-print Network

Test pattern generation is an electronic design automation tool that attempts to find an input (or test) sequence that, when applied to a digital circuit, enables one to distinguish between the correct circuit behavior and the faulty behavior caused by particular faults. The effectiveness of this classical method is measured by the fault coverage achieved for the fault model and the number of generated vectors, which should be directly proportional to test application time. This work address the quantum process validation problem by considering the quantum mechanical adaptation of test pattern generation methods used to test classical circuits. We found that quantum mechanics allows one to execute multiple test vectors concurrently, making each gate realized in the process act on a complete set of characteristic states in space/time complexity that breaks classical testability lower bounds.

Jacob Biamonte; Marek Perkowski

2005-01-20

269

Relationship between Bouguer anomaly and active fault ( source fault) - For the purpose of estimate of source fault -  

NASA Astrophysics Data System (ADS)

Concepts of setting source fault parameters from active faults are discussed for predictions of strong ground motion. Estimation of ground motion plays important rule for the prevention of earthquake hazards. From recent developments in waveform inversion analysis of source fault rupture processes through large earthquakes, it is found that strong ground motion is strongly affected by fault geometry and slip heterogeneity. At the prediction of strong ground motions for scenario earthquakes by active faults, the initial parameters of source faults, such as fault length, direction and dip are thus necessary to be determined. However, the study about relation between source fault and surface rupture, source fault length are certainly longer than surface ruptures (Kitada et al, 2004) and it is difficult to estimate exactly source fault length from the information around surface fault. In case of estimate the source fault, it might be better using spatial underground structure and its information such as gravity. Inoue et al (2007) discussed the relation between source fault and gravity data and suggest the short wave length component of bouguer anomaly have the possibility to show the distribution of density around seismogenic zone. In this study, we consider the length of source fault for scenario earthquake by distribution of the short wave length component of bouguer anomaly. The short wave length component of bouguer anomaly shows the relative high density area and low density area. These areas indicate the same tectonic block. Source fault are distributed not only on the boundary of these block but also in the same tectonic block. Therefore, the source fault seems to be difficult to continue over the other block.

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

2008-12-01

270

Seismic and aseismic deformation associated with the 1952 Kern County, California, earthquake and relationship to the quaternary history of the White Wolf fault  

SciTech Connect

Synthesis of geodetic, and seismic data from the White Wolf fault, California, indicates that the fault separates an area of late Quaternary and continuing rapid uplift in the Tehachapi Mountains and Transverse Ranges from even more rapid subsidence in the southern San Joaquin Valley. On July 21, 1952, rupture of the White Wolf fault produced the M/sub L/ = 7.2 Kern County earthquake. We used the aftershock zone to delimit the size of the faulted slip surface and applied constraints imposed by the known 1952--1953 horizontal shear strains to model the measured coseismic vertical displacements, with an elastic dislocation model. A curved fault trace with decreasing fault depth (27 to 10 km from the surface vertically to the base), slip (3 to 1 m), and dip (75/sup 0/ to 20/sup 0/) from the 1952 epicenter at the southwest end of the fault toward the northeast provides the fit most consistent with the geodetic record, the measured seismic moment, the fault-plane solution, and the pattern of surface rupture. Two short releveled lines near the 1952 epicenter tilted 4 and 17 ..mu..rad down to the north from 5--10 years before the earthquake; the preseismic tilts differ significantly from ten other surveys of these lines. Left-lateral fault-crossing shear strain from 0.2--20 years before the quake was two times greater than both preseismic off-fault strains and the post-seismic fault-crossing strains. During the first seven years after the earthquake, aseismic deformation was negligible. From 1959 to 1972 uplift reached 160 mm over an area larger than the aftershock zone, rising first in the epicentral region and then at the northeast end of the fault. This was unaccompanied by any surface fault slip. Reconstruction of the vertical separation on the White Wolf fault from late Quaternary and late Miocene stratigraphic marker beds.

Stein, R.S.; Thatcher, W.

1981-06-10

271

A Thermal Technique of Fault Nucleation, Growth, and Slip  

NASA Astrophysics Data System (ADS)

Fractures and fluids influence virtually all mechanical processes in the crust, but many aspects of these processes remain poorly understood largely because of a lack of controlled field experiments at appropriate scale. We have developed an in-situ experimental approach to create carefully controlled faults at scale of ~10 meters using thermal techniques to modify in situ stresses to the point where the rock fails in shear. This approach extends experiments on fault nucleation and growth to length scales 2-3 orders of magnitude greater than are currently possible in the laboratory. The experiments could be done at depths where the modified in situ stresses are sufficient to drive faulting, obviating the need for unrealistically large loading frames. Such experiments require an access to large rock volumes in the deep subsurface in a controlled setting. The Deep Underground Science and Engineering Laboratory (DUSEL), which is a research facility planned to occupy the workings of the former Homestake gold mine in the northern Black Hills, South Dakota, presents an opportunity for accessing locations with vertical stresses as large as 60 MPa (down to 2400 m depth), which is sufficient to create faults. One of the most promising methods for manipulating stresses to create faults that we have evaluated involves drilling two parallel planar arrays of boreholes and circulating cold fluid (e.g., liquid nitrogen) to chill the region in the vicinity of the boreholes. Cooling a relatively small region around each borehole causes the rock to contract, reducing the normal compressive stress throughout much larger region between the arrays of boreholes. This scheme was evaluated using both scaling analysis and a finite element code. Our results show that if the boreholes are spaced by ~1 m, in several days to weeks, the normal compressive stress can be reduced by 10 MPa or more, and it is even possible to create net tension between the borehole arrays. According to the Mohr-Coulomb strength criterion with standard Byerlee parameters, a fault will initiate before the net tension occurs. After a new fault is created, hot fluid can be injected into the boreholes to increase the temperature and reverse the direction of fault slip. This process can be repeated to study the formation of gouge, and how the properties of gouge control fault slip and associated seismicity. Instrumenting the site with arrays of geophones, tiltmeters, strain gauges, and displacement transducers as well as back mining - an opportunity provided by the DUSEL project - can reveal details of the fault geometry and gouge. We also expect to find small faults (with cm-scale displacement) during construction of DUSEL drifts. The same thermal technique can be used to induce slip on one of them and compare the “man-made” and natural gouges. The thermal technique appears to be a relatively simple way to rapidly change the stress field and either create slip on existing fractures or create new faults at scales up to 10 m or more.

Garagash, D.; Germanovich, L. N.; Murdoch, L. C.; Martel, S. J.; Reches, Z.; Elsworth, D.; Onstott, T. C.

2009-12-01

272

Early Alleghanian oblique dextral extension and magmatism along the Modoc fault zone, eastern Appalachian Piedmont, SC-GA  

SciTech Connect

The Modoc fault zone is a prominent zone of simple shear that has been mapped for 250 km from near Columbia, SC to the Ocmulgee River, in central GA. The steeply northwest-dipping fault zone is up to 5 km wide and contains variably mylonitic paragneiss and synkinematic sheets of mylonitic granite. Rotated tension gashes, reverse-slip-slip-crenulations, and asymmetric porphyroclasts in the fault zone are interpreted to indicate oblique dextral and normal movement. U/Pb zircon ages of 315--300 Ma yielded by some of these granite sheets are interpreted to date the time of movement on the Modoc fault zone, relatively early during the Alleghanian orogeny (ca 330--265Ma). Concurrent with movement along the Modoc fault zone, granite bodies (dated at 320--300 Ma) were intruded into both the hangingwall and the footwall sides of the fault. Cooling ages of ca 308 Ma (U/Pb monazite) and ca 305--288 Ma (40Ar/39Ar hornblende) from footwall rocks near the Savannah River indicate rapid cooling from temperatures above 700 starting with movement along the Modoc fault zone. Published geobarometry results suggest that footwall rocks were uplifted from depths of ca 29km and juxtaposed next to hangingwall rocks at depths of ca 11km by movement along the Modoc fault zone. Taken together, the crustal omission, uplift and rapid cooling of the footwall blocks, and the oblique normal sense of shear indicate at least a component of crustal extension along the Modoc fault zone. Intrusion of granite into and adjacent to the fault indicates magmatism accompanied movement on the fault at ca 315--300 Ma. Regardless of tectonic mechanism, extension associated with either crustal delamination or dextral transcurrent motion of accreted terranes, it is clear that crustal extension and magmatism was important during early phases of the Alleghanian orogeny in this part of the orogen, and it may have also been important elsewhere.

Sacks, P.E. (Western Michigan Univ., Kalamazoo, MI (United States). Geology); Secor, D.T. Jr. (Univ. of South Carolina, Columbia, SC (United States). Geological Sciences); Maher, H.D. Jr. (Univ. of Nebraska, Omaha, NE (United States). Geography and Geology); Wright, J. (Rice Univ., Houston, TX (United States). Geology and Geophysics); Dallmeyer, R.D. (Univ. of Georgia, Athens, GA (United States). Geology)

1993-03-01

273

Focused exhumation along megathrust splay faults in Prince William Sound, Alaska  

NASA Astrophysics Data System (ADS)

Megathrust splay faults have been identified as important for generating tsunamis in some subduction zone earthquakes (1946 Nankai, 1964 Alaska, 2004 Sumatra). The larger role of megathrust splay faults in accretionary prisms is not well known. In Alaska, we have new evidence that megathrust splay faults are conduits for focused exhumation. In the southern Alaska accretionary complex, in the Prince William Sound region above the 1964 M9.2 earthquake rupture, apatite (U-Th)/He (AHe) ages, with closure temperatures of about 65°C, are typically in the range of 10-20 Ma. These relatively old ages indicate little to no accumulation of permanent strain during the megathrust earthquake cycle. However, the youngest AHe ages in all of Prince William Sound are from Montague Island, with two ages of 1.4 Ma on the southwest part of the island and two ages of 4 Ma at the northeast end of the island. Montague Island lies in the hanging wall of the Patton Bay megathrust splay fault, which ruptured during the 1964 earthquake, and resulted in 9 m of vertical uplift. Two other megathrust splay faults also ruptured during the 1964 earthquake in the same area. New high-resolution bathymetry and seismic reflection profiles show abundant normal faults in the region adjacent and north of the megathrust splay faults. The largest of these is the Montague Strait fault, which has 80 m of post glacial offset (~12kya?). We interpret this extension in the hanging wall as accommodating the exhumation of the rocks on Montague Island along the megathrust splay faults. An examination of legacy seismic reflection profiles shows the megathrust splay faults rooting downward into the decollement. At least some extension in the hanging wall may also be related to thrusting over a ramp-flat geometry. These megathrust splay faults are out of sequence thrusts, as they are located about 130 km inboard from the trench. This out of sequence thrusting that is causing the exhumation on Montague Island may be driven by underplating or by the Yakutat microplate collision. We suggest that rapid exhumation along megathrust splay faults, in association with normal faulting, may be a feature along other megathrust splay faults around the world.

Haeussler, P. J.; Armstrong, P. A.; Liberty, L. M.; Ferguson, K.; Finn, S.; Arkle, J. C.; Pratt, T. L.

2011-12-01

274

Fault Tree XML {syjsmk, ldalove, jbyoo}@konkuk.ac.kr  

E-print Network

. 1. (FTA, Fault Tree Analysis) / , [1]. , . 1 FTA . 1. FTA(Fault Tree Analysis)[1] XML . XML [2]. (FT, Fault Tree) XML Fault Tree Analysis", Transactions of Korean Nuclear Society, vol.1, Pages 855-857, 2010 #12;

275

Automated Fault Location In Smart Distribution Systems  

E-print Network

of utilizing a suitable fault location method. As distribution systems are gradually evolving into smart distribution systems, application of more accurate fault location methods based on gathered data from various Intelligent Electronic Devices (IEDs...

Lotfifard, Saeed

2012-10-19

276

An experimental study of memory fault latency  

NASA Technical Reports Server (NTRS)

The difficulty with the measurement of fault latency is due to the lack of observability of the fault occurrence and error generation instants in a production environment. The authors describe an experiment, using data from a VAX 11/780 under real workload, to study fault latency in the memory subsystem accurately. Fault latency distributions are generated for stuck-at-zero (s-a-0) and stuck-at-one (s-a-1) permanent fault models. The results show that the mean fault latency of an s-a-0 fault is nearly five times that of the s-a-1 fault. An analysis of variance is performed to quantify the relative influence of different workload measures on the evaluated latency.

Chillarege, Ram; Iyer, Ravi K.

1989-01-01

277

Underground distribution cable incipient fault diagnosis system  

E-print Network

This dissertation presents a methodology for an efficient, non-destructive, and online incipient fault diagnosis system (IFDS) to detect underground cable incipient faults before they become catastrophic. The system provides vital information...

Jaafari Mousavi, Mir Rasoul

2007-04-25

278

Solar Dynamic Power System Fault Diagnosis  

NASA Technical Reports Server (NTRS)

The objective of this research is to conduct various fault simulation studies for diagnosing the type and location of faults in the power distribution system. Different types of faults are simulated at different locations within the distribution system and the faulted waveforms are monitored at measurable nodes such as at the output of the DDCU's. These fault signatures are processed using feature extractors such as FFT and wavelet transforms. The extracted features are fed to a clustering based neural network for training and subsequent testing using previously unseen data. Different load models consisting of constant impedance and constant power are used for the loads. Open circuit faults and short circuit faults are studied. It is concluded from present studies that using features extracted from wavelet transforms give better success rates during ANN testing. The trained ANN's are capable of diagnosing fault types and approximate locations in the solar dynamic power distribution system.

Momoh, James A.; Dias, Lakshman G.

1996-01-01

279

Parametric Modeling and Fault Tolerant Control  

NASA Technical Reports Server (NTRS)

Fault tolerant control is considered for a nonlinear aircraft model expressed as a linear parameter-varying system. By proper parameterization of foreseeable faults, the linear parameter-varying system can include fault effects as additional varying parameters. A recently developed technique in fault effect parameter estimation allows us to assume that estimates of the fault effect parameters are available on-line. Reconfigurability is calculated for this model with respect to the loss of control effectiveness to assess the potentiality of the model to tolerate such losses prior to control design. The control design is carried out by applying a polytopic method to the aircraft model. An error bound on fault effect parameter estimation is provided, within which the Lyapunov stability of the closed-loop system is robust. Our simulation results show that as long as the fault parameter estimates are sufficiently accurate, the polytopic controller can provide satisfactory fault-tolerance.

Wu, N. Eva; Ju, Jianhong

2000-01-01

280

Dislocation model for aseismic fault slip in the transverse ranges of Southern California  

NASA Technical Reports Server (NTRS)

Geodetic data at a plate boundary can reveal the pattern of subsurface displacements that accompany plate motion. These displacements are modelled as the sum of rigid block motion and the elastic effects of frictional interaction between blocks. The frictional interactions are represented by uniform dislocation on each of several rectangular fault patches. The block velocities and fault parameters are then estimated from geodetic data. Bayesian inversion procedure employs prior estimates based on geological and seismological data. The method is applied to the Transverse Ranges, using prior geological and seismological data and geodetic data from the USGS trilateration networks. Geodetic data imply a displacement rate of about 20 mm/yr across the San Andreas Fault, while the geologic estimates exceed 30 mm/yr. The prior model and the final estimates both imply about 10 mm/yr crustal shortening normal to the trend of the San Andreas Fault. Aseismic fault motion is a major contributor to plate motion. The geodetic data can help to identify faults that are suffering rapid stress accumulation; in the Transverse Ranges those faults are the San Andreas and the Santa Susana.

Cheng, A.; Jackson, D. D.; Matsuura, M.

1985-01-01

281

Mechanical Role of Fluids in Earthquakes and Faulting  

NASA Astrophysics Data System (ADS)

Following the contributions of Hubbert and Rubey, the level of ambient pore pressure is of accepted importance for understanding the static frictional strength of faults. There are also important dynamical interactions between pore fluids and faulting. Some of those are addressed here, with examples to be chosen from the following: (1) Pore fluid presence at full saturation promotes strong localization in rapidly shearing granular materials, even in cases for which the friction coefficient increases rapidly with shearing rate [see Rice, Rudnicki and Tsai, this meeting]. (2) Thermal pressurization of earthquake faults during seismic slip may provide the primary weakening process during earthquakes in mature crustal fault zones; it provides a plausible basic explanation, based on geological and laboratory data, of the magnitudes of the fracture energies of earthquakes as inferred independently from seismological data [see web link below]. The process also seems to be active in some large landslides. (3) Pore pressure alterations are induced by rapid mode II slip on fault planes when they have bordering gouge or damage zones which are of dissimilar permeability and/or poroelastic properties. This provides a fuller, new perspective on effects of material dissimilarity across a slip surface on altering the effective normal stress and thus interacting with dynamic rupture [see Rudnicki and Rice, this meeting]. (4) Gouge dilatancy associated with slip-rate increases induces suction in the pore fluid, so as to partially stabilize faults against earthquake nucleation, and also to slow rupture propagation into shallow fault regions. An open question is that of when and if shear heating acts to aid nucleation; the effect seems negligible for nucleation under slow tectonic loading but may be important for nucleation driven by sudden steps in stress. (5) Permeability determines pore pressure gradients for given flow rates, but increases in pore pressure cause increases in permeability. That allows slow solitary waves of pore pressure increase which propagate upwards against gravity in fault zones that are reasonably sealed from their surroundings, following initiation by, e.g., breaching of a pressurized seal at depth. (6) Aseismic slip transients in subduction zones occur in an environment of active compaction and metamorphic fluid release, and fluids seem responsible for associated tremor as well. Recent modeling [see Liu and Rice, this meeting] links elevation of fluid pressure to the speed of along-strike propagation of slip transients. (7) Poroelastic responses to stress transfer have been detected for some earthquakes, and associated transient stress changes may play a role in aftershock sequences, although probably secondary in general. (8) Another type of fluid saturated ``fault zone'', in granulated sediments between dissimilar materials, is the bed of a mobile ice sheet. Some of the concepts in topics 1 to 4 above may have application to surges, ice streams, and glacial earthquakes. These various cases 1 to 8 involve many contributors in the geophysical community, and include collaborative current or recent studies of the author with Massimo Cocco (2), Yajing Liu (4, 6), Alan Rempel (2), John Rudnicki (1,3), Paul Segall (4), and Victor Tsai (1,8).

Rice, J. R.

2005-12-01

282

Fault Behavior and Characteristic Earthquakes: Examples From the Wasatch and San Andreas Fault Zones  

Microsoft Academic Search

Paleoseismological data for the Wasatch and San Andreas fault zones have led to the formulation of the characteristic earthquake model, which postulates that individual faults and fault segments tend to generate essentially same size or characteristic earthquakes having a relatively narrow range of magnitudes near the maximum. Analysis of scarp-derived colluvium in trench exposures across the Wasatch fault provides estimates

David P. Schwartz; Kevin J. Coppersmith

1984-01-01

283

High-resolution stratigraphy reveals repeated earthquake faulting in the Masada Fault Zone, Dead Sea Transform  

E-print Network

High-resolution stratigraphy reveals repeated earthquake faulting in the Masada Fault Zone, Dead lacustrine laminites in the Dead Sea Basin near Masada. The Masada Fault Zone offers a unique opportunity of the syndepositional Masada Fault Zone (MFZ) provides an example for fundamental characteristics of earthquakes

Marco, Shmuel "Shmulik"

284

Efficient Fault Tolerance: an Approach to Deal with Transient Faults in Multiprocessor Architectures  

E-print Network

Efficient Fault Tolerance: an Approach to Deal with Transient Faults in Multiprocessor be integrated with a fault treatment approach aiming at op- timising resource utilisation. In this paper we propose a diagnosis approach that, accounting for transient faults, tries to remove units very cautiously

Firenze, Università degli Studi di

285

Multi-Sensor Fault Recovery in the Presence of Known and Unknown Fault Types  

E-print Network

Multi-Sensor Fault Recovery in the Presence of Known and Unknown Fault Types Steven Reece in the presence of modelled and unmodelled faults. The al- gorithm comprises two stages. The first stage attempts to re- move modelled faults from each individual sensor estimate. The second stage de

Roberts, Stephen

286

Fault grading operational self-test  

Microsoft Academic Search

A study is presented on fault grading of the OST (operation self-test) for a Delco VHSIC 1750A computer in its early design phases, using a commercially available hardware accelerator. The OST fault-grading effort illustrated the need for design methodologies that take into consideration the capabilities of today's CAE tools. A fault simulation methodology and design guidelines for optimizing the fault

Robert T. Aparicio; Patrick J. Hallinan

1989-01-01

287

Delving into faults and earthquake behavior.  

PubMed

Seismologists attending last month's meeting of the American Geophysical Union in San Francisco heard much about how the irregularities on faults control their behavior and thus the generation of earthquakes. The identification of small crucial areas of a fault, such as the strong spot where a rupture can begin or the fault jog where it can end, is proving a challenge, but it also offers one of the best hopes of understanding and predicting fault behavior. PMID:17778628

Kerr, R A

1987-01-01

288

Fault Models for Quantum Mechanical Switching Networks  

E-print Network

The difference between faults and errors is that, unlike faults, errors can be corrected using control codes. In classical test and verification one develops a test set separating a correct circuit from a circuit containing any considered fault. Classical faults are modelled at the logical level by fault models that act on classical states. The stuck fault model, thought of as a lead connected to a power rail or to a ground, is most typically considered. A classical test set complete for the stuck fault model propagates both binary basis states, 0 and 1, through all nodes in a network and is known to detect many physical faults. A classical test set complete for the stuck fault model allows all circuit nodes to be completely tested and verifies the function of many gates. It is natural to ask if one may adapt any of the known classical methods to test quantum circuits. Of course, classical fault models do not capture all the logical failures found in quantum circuits. The first obstacle faced when using methods from classical test is developing a set of realistic quantum-logical fault models. Developing fault models to abstract the test problem away from the device level motivated our study. Several results are established. First, we describe typical modes of failure present in the physical design of quantum circuits. From this we develop fault models for quantum binary circuits that enable testing at the logical level. The application of these fault models is shown by adapting the classical test set generation technique known as constructing a fault table to generate quantum test sets. A test set developed using this method is shown to detect each of the considered faults.

Jacob Biamonte; Jeff S. Allen; Marek A. Perkowski

2005-08-19

289

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

290

The 2008 Yutian normal faulting earthquake (Mw 7.1), NW Tibet: Nonplanar fault modeling and implications for the Karakax Fault  

Microsoft Academic Search

The ENE striking Altyn-Tagh Fault and the WNW striking Karakax Fault are two major strike–slip fault systems in northern Tibet, and form a prominent ~2000km long fault system. The 2008 Yutian normal faulting earthquake (Mw 7.1) struck near the southern edge of the Tarim Basin, where the two fault systems converge. While there are numerous NS-trending normal faults particularly in

Masato Furuya; Takatoshi Yasuda

291

Fault-related clay authigenesis along the Moab Fault: Implications for calculations of fault rock composition and mechanical and hydrologic fault zone properties  

USGS Publications Warehouse

The presence of clays in fault rocks influences both the mechanical and hydrologic properties of clay-bearing faults, and therefore it is critical to understand the origin of clays in fault rocks and their distributions is of great importance for defining fundamental properties of faults in the shallow crust. Field mapping shows that layers of clay gouge and shale smear are common along the Moab Fault, from exposures with throws ranging from 10 to ???1000 m. Elemental analyses of four locations along the Moab Fault show that fault rocks are enriched in clays at R191 and Bartlett Wash, but that this clay enrichment occurred at different times and was associated with different fluids. Fault rocks at Corral and Courthouse Canyons show little difference in elemental composition from adjacent protolith, suggesting that formation of fault rocks at those locations is governed by mechanical processes. Friction tests show that these authigenic clays result in fault zone weakening, and potentially influence the style of failure along the fault (seismogenic vs. aseismic) and potentially influence the amount of fluid loss associated with coseismic dilation. Scanning electron microscopy shows that authigenesis promotes that continuity of slip surfaces, thereby enhancing seal capacity. The occurrence of the authigenesis, and its influence on the sealing properties of faults, highlights the importance of determining the processes that control this phenomenon. ?? 2010 Elsevier Ltd.

Solum, J.G.; Davatzes, N.C.; Lockner, D.A.

2010-01-01

292

Failure and Fault Analysis for Software Debugging  

Microsoft Academic Search

Most studies of software failures and faults have done little more than classify failures and faults collected from long-term projects. The authors propose a model to analyze failures and faults for debugging purposes. In the model, they define “failure modes” and “failure types” to identify the existence of program failures and the nature of the program failures, respectively. The goal

Richard A. Demillo; Hsin Pant; Eugene H. Spafford

1997-01-01

293

The Fault Detection Problem Andreas Haeberlen1  

E-print Network

The Fault Detection Problem Andreas Haeberlen1 and Petr Kuznetsov2 1 Max Planck Institute challenges in distributed com- puting is ensuring that services are correct and available despite faults. Recently it has been argued that fault detection can be factored out from computation, and that a generic

Pennsylvania, University of

294

The Fault Detection Problem Andreas Haeberlen  

E-print Network

The Fault Detection Problem Andreas Haeberlen Petr Kuznetsov Abstract One of the most important challenges in distributed computing is ensuring that services are correct and available despite faults. Recently it has been argued that fault detection can be factored out from computation, and that a generic

Pennsylvania, University of

295

Active faulting and tectonics in China  

Microsoft Academic Search

We present a study of the active tectonics of China based on an interpretation of Landsat (satellite) imagery and supplemented with seismic data. Several important fault systems can be identified, and most are located in regions of high historical seismicity. We deduce the type and sense of faulting from adjacent features seen on these photos, from fault plane solutions of

Paul Tapponnier; Peter Molnar

1977-01-01

296

High temperature superconducting fault current limiter  

DOEpatents

A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

Hull, J.R.

1997-02-04

297

Fault detection and diagnosis in rotating machinery  

Microsoft Academic Search

The detection and diagnosis of mechanical faults in rotating machinery using a model-based approach is studied. For certain types of faults, for example raceway faults in rolling element bearings, increase in mass unbalance and changes in stiffness and damping, algorithms suitable for real-time implementation are developed and tested

Kenneth A. Loparo; Nader Afshari; Mohammed Abdel-Magied

1998-01-01

298

Fault detection and diagnosis of rotating machinery  

Microsoft Academic Search

A model-based approach to the detection and diagnosis of mechanical faults in rotating machinery is studied in this paper. For certain types of faults, for example, raceway faults in rolling element bearings, an increase in mass unbalance, and changes in stiffness and damping, algorithms suitable for real-time implementation are developed and evaluated using computer simulation

Kenneth A. Loparo; M. L. Adams; Wei Lin; M. Farouk Abdel-Magied; Nadar Afshari

2000-01-01

299

Fault-Tolerant Facility Location Chaitanya Swamy  

E-print Network

-tolerant generalization of the classical uncapacitated facility location problem. We want to open a subset of facilities + ) [1]. The fault-tolerant facility location problem was introduced by Jain & Vazirani [10] who gaveFault-Tolerant Facility Location Chaitanya Swamy David B. Shmoys We study a fault

Swamy, Chaitanya

300

Fault tree analysis with fuzzy gates  

Microsoft Academic Search

Fault tree analysis is an important tool analyzing system reliability. Fault trees consist of gates and events. Gates mean relationships between events. In fault tree analysis, AND, OR gates have been used as typical gates but it is often difficult to model the system structure with the two gates because in many cases we have not exact knowledge on system

HanSuk Pan; WonYoung Yun

1997-01-01

301

Reliability computation using fault tree analysis  

NASA Technical Reports Server (NTRS)

A method is presented for calculating event probabilities from an arbitrary fault tree. The method includes an analytical derivation of the system equation and is not a simulation program. The method can handle systems that incorporate standby redundancy and it uses conditional probabilities for computing fault trees where the same basic failure appears in more than one fault path.

Chelson, P. O.

1971-01-01

302

Safety Requirements and Fault Trees using Retrenchment  

E-print Network

. Veri#12;cation techniques such as Fault Tree Analysis can then be used to establish the root causeSafety Requirements and Fault Trees using Retrenchment R. Banach and R. Cross Computer Science trees for the faults introduced during the injection process. A two bit adder example drawn from

Banach, Richard

303

Functional test generation for path delay faults  

Microsoft Academic Search

We present a novel test generation technique for path delay faults, based on the growth (G) and disappearance (D) faults of programmable logic arrays (PLA). The circuit is modeled as a PLA that is prime and irredundant with respect to every output. Certain tests for G faults, generated by using known efficient methods are transformed into tests for path delay

Mandyam-komar Srinivas; Vishwani D. Agrawal; Michael L. Bushnell

1995-01-01

304

Ground Fault--A Health Hazard  

ERIC Educational Resources Information Center

A ground fault is especially hazardous because the resistance through which the current is flowing to ground may be sufficient to cause electrocution. The Ground Fault Circuit Interrupter (G.F.C.I.) protects 15 and 25 ampere 120 volt circuits from ground fault condition. The design and examples of G.F.C.I. functions are described in this article.…

Jacobs, Clinton O.

1977-01-01

305

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 2013-01-01 false Fault. 831.1402 Section 831.1402 Administrative...for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of...

2013-01-01

306

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2012 CFR

... 2012-04-01 2012-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...SERVICE PENSION SYSTEM (FSPS) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2012-04-01

307

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 2012-01-01 false Fault. 845.302 Section 845.302 Administrative...Standards for Waiver of Overpayments § 845.302 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2012-01-01

308

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 2011-01-01 false Fault. 845.302 Section 845.302 Administrative...Standards for Waiver of Overpayments § 845.302 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2011-01-01

309

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2012-04-01 true Fault. 255.11 Section 255.11 Employees...RECOVERY OF OVERPAYMENTS § 255.11 Fault. (a) Before recovery of an overpayment...that the overpaid individual was without fault in causing the overpayment. If...

2013-04-01

310

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Fault. 255.11 Section 255.11 Employees...RECOVERY OF OVERPAYMENTS § 255.11 Fault. (a) Before recovery of an overpayment...that the overpaid individual was without fault in causing the overpayment. If...

2012-04-01

311

5 CFR 845.302 - Fault.  

Code of Federal Regulations, 2013 CFR

... 2013-01-01 2013-01-01 false Fault. 845.302 Section 845.302 Administrative...Standards for Waiver of Overpayments § 845.302 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2013-01-01

312

20 CFR 255.11 - Fault.  

...2014-04-01 2012-04-01 true Fault. 255.11 Section 255.11 Employees...RECOVERY OF OVERPAYMENTS § 255.11 Fault. (a) Before recovery of an overpayment...that the overpaid individual was without fault in causing the overpayment. If...

2014-04-01

313

5 CFR 831.1402 - Fault.  

... 2014-01-01 2014-01-01 false Fault. 831.1402 Section 831.1402 Administrative...for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of...

2014-01-01

314

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2010 CFR

... 2010-01-01 2010-01-01 false Fault. 831.1402 Section 831.1402 Administrative...for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of...

2010-01-01

315

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2013 CFR

... 2013-04-01 2013-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...SERVICE PENSION SYSTEM (FSPS) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2013-04-01

316

22 CFR 17.3 - Fault.  

Code of Federal Regulations, 2011 CFR

... 2011-04-01 2011-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...SERVICE PENSION SYSTEM (FSPS) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2011-04-01

317

22 CFR 17.3 - Fault.  

... 2014-04-01 2014-04-01 false Fault. 17.3 Section 17.3 Foreign Relations...SERVICE PENSION SYSTEM (FSPS) § 17.3 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2014-04-01

318

FAULT PREDICTIVE CONTROL OF COMPACT DISK PLAYERS  

E-print Network

FAULT PREDICTIVE CONTROL OF COMPACT DISK PLAYERS Peter Fogh Odgaard Mladen Victor Wickerhauser playing certain discs with surface faults like scratches and fingerprints. The problem is to be found in an other publications of the first author. This scheme is based on an assumption that the surface faults do

Wickerhauser, M. Victor

319

20 CFR 255.11 - Fault.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Fault. 255.11 Section 255.11 Employees...RECOVERY OF OVERPAYMENTS § 255.11 Fault. (a) Before recovery of an overpayment...that the overpaid individual was without fault in causing the overpayment. If...

2011-04-01

320

5 CFR 845.302 - Fault.  

... 2014-01-01 2014-01-01 false Fault. 845.302 Section 845.302 Administrative...Standards for Waiver of Overpayments § 845.302 Fault. A recipient of an overpayment is without fault if he or she performed no act of...

2014-01-01

321

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2012 CFR

... 2012-01-01 2012-01-01 false Fault. 831.1402 Section 831.1402 Administrative...for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of...

2012-01-01

322

5 CFR 831.1402 - Fault.  

Code of Federal Regulations, 2011 CFR

... 2011-01-01 2011-01-01 false Fault. 831.1402 Section 831.1402 Administrative...for Waiver of Overpayments § 831.1402 Fault. A recipient of an overpayment is without fault if he/she performed no act of...

2011-01-01

323

Field Trip to the Hayward Fault Zone  

NSDL National Science Digital Library

This guide provides directions to locations in Hayward, California where visitors can see evidence of creep along the Hayward Fault. There is also information about the earthquake hazards associated with fault zones, earthquake prediction, and landforms associated with offset along a fault. The guide is available in downloadable, printable format (PDF) in two resolutions

324

Fault-crossing P delays, epicentral biasing, and fault behavior in Central California  

USGS Publications Warehouse

The P delays across the San Andreas fault zone in central California have been determined from travel-time differences at station pairs spanning the fault, using off-fault local earthquake or quarry blast sources. Systematic delays as large as 0.4 sec have been observed for paths crossing the fault at depths of 5-10 km. These delays can account for the apparent deviation of epicenters from the mapped fault trace. The largest delays occur along the San Andreas fault between San Juan Bautista and Bear Valley and Between Bitterwater Valley and Parkfield. Spatial variations in fault behavior correlate with the magnitude of the fault-crossing P delay. The delay decreases to the northwest of San Juan Bautista across the "locked" section of the San Andreas fault and also decreases to the southeast approaching Parkfield. Where the delay is large, seismicity is relatively high and the fault is creeping. ?? 1979.

Marks, S.M.; Bufe, C.G.

1979-01-01

325

Seismic Velocity Changes Associated With Static Stress Related Fault Unclamping  

Microsoft Academic Search

Seismic velocities across faults are sensitive to fault stiffness. Faults stiffness varies as a function of the stress state of a fault, hence stress perturbations are expected to cause associated changes in the propagation velocities of seismic waves across individual faults or fault systems. Very high precision temporal variations in seismic wave velocity can be made by applying the Coda

C. J. Bean; L. Cociani; H. Lyon-Caen

2008-01-01

326

Fault branching and rupture directivity  

Microsoft Academic Search

Could the directivity of a complex earthquake be inferred from the ruptured fault branches it created? Typically, branches develop in forward orientation, making acute angles relative to the propagation direction. Direct backward branching of the same style as the main rupture (e.g., both right lateral) is disallowed by the stress field at the rupture front. Here we propose another mechanism

Sonia Fliss; Harsha S. Bhat; Renata Dmowska; James R. Rice

2005-01-01

327

Cell boundary fault detection system  

DOEpatents

An apparatus and program product determine a nodal fault along the boundary, or face, of a computing cell. Nodes on adjacent cell boundaries communicate with each other, and the communications are analyzed to determine if a node or connection is faulty.

Archer, Charles Jens (Rochester, MN); Pinnow, Kurt Walter (Rochester, MN); Ratterman, Joseph D. (Rochester, MN); Smith, Brian Edward (Rochester, MN)

2011-04-19

328

HTS fault current limiter concept  

Microsoft Academic Search

Fault current limiter (FCL) concepts based on non-inductive high temperature superconducting (HTS) coils were studied. The coils employed second generation (2G) HTS wire based on YBCO coated conductor currently under development at American superconductor corporation (AMSC) and other places. Two FCL concepts were studied: a) series and b) shunt. The series limiter employs a coil in series with the load

S. S. Kalsi; A. Malozemoff

2004-01-01

329

Ground Penetrating Radar Investigations of Shallow Active Faults along the Southern Dead Sea Transform in Aqaba, Jordan  

NASA Astrophysics Data System (ADS)

The city of Aqaba is situated at the northern end of Gulf of Aqaba along the southern part of the Dead Sea Transform (DST) which is the main source of seismic activity in the region. A ground penetrating radar (GPR) survey was carried out Aqaba under the MERC M25-004 Project that seeks to map the active faults submerged in the northern gulf that lie immediately offshore and the faults that lie onshore beneath the rapidly developing cities of Aqaba and Eilat. Approximately 3000 m of GPR lines were collected in Aqaba with a 100 MHz monostatic antennas. The maximum depth of penetration was with approximately 5 meter. The GPR survey conducted in Aqaba reveals several different kinds of anomalies and discontinuities. In order to enhance our interpration of the GPR anomalies, we collected several GPR lines across several locations in the city where faults, fractures, and channels have been mapped in trench exposures. Analysis of the anomalies and discontinuities in GPR cross section (radagram) can be interpreted as a set of shallow fractures and faults within various lithologic changes. All the detected faults located by GPR survey are shallow less than 5 m depth and have vertical small displacement within late Quaternary sediments. The GPR anomalies appear to align along three NE-trending fault zones in the city of Aqaba. These zones, that we call the Ayla fault, the West Aqaba fault, and the Aqaba fault zone, appear to be on land extensions of faults that have been imaged offshore in the Gulf of Aqaba as part of our recent marine geophysical survey. This study indicates that there are more active faults within the region than previously mapped. Studying the late Quaternary sediments would provide a way to characterize the seismic hazard potential of faults

Abueladas, A. A.

2009-12-01

330

Safety assessment for safety-critical systems including physical faults and design faults  

Microsoft Academic Search

Two types of faults, design faults and physical faults, are discussed in this paper. Since they are two mutually exclusive and complete fault types on the fault space, the safety assessment of safety-critical computer systems in this paper considers the hazard contribution from both types. A three-state Markov model is introduced to model safety-critical systems. Steady state safety and mean

Yangyang Yu; Barry W. Johnson

2006-01-01

331

Prehistoric fault offsets of the Hilina fault system, south flank of Kilauea Volcano, Hawaii  

Microsoft Academic Search

Historical accounts of earthquakes on the Island of Hawaii date only to 1823 but lava flows as old as 1500-3000 years B.P. contain fault offsets from prehistoric earthquakes. The M7.2 1975 Kalapana earthquake produced over 25 km of fault rupture along the Hilina fault system. We compare fault offsets in prehistoric lava flows with Kalapana earthquake fault offsets in neighboring

Eric C. Cannon; Roland Bürgmann

2001-01-01

332

A data-driven fault tolerant model predictive control with fault identification  

Microsoft Academic Search

Most of the existing active control methodologies need a post-fault\\/failure model of the faulty process for online retuning the controller parameters, or reconfiguration. However, post-fault model identification process takes the precious post-fault time which delays the recovery procedure. A new data-driven fault tolerant model predictive control (MPC) is developed which does not need the post-fault model. In fact, the model

Hojjat A. Izadi; Brandon W. Gordon; Youmin Zhang

2010-01-01

333

San Andreas Fault damage at SAFOD viewed with fault-guided waves  

Microsoft Academic Search

Highly damaged rocks within the San Andreas fault zone at Parkfield form a low-velocity waveguide for seismic waves, giving rise to fault-guided waves. Prominent fault-guided waves have been observed at the San Andreas Fault Observatory at Depth (SAFOD) site, including a surface array across the fault zone and a borehole seismograph placed in the SAFOD well at a depth of

Yong-Gang Li; Peter E. Malin

2008-01-01

334

Fault-Tolerant Heat Exchanger  

NASA Technical Reports Server (NTRS)

A compact, lightweight heat exchanger has been designed to be fault-tolerant in the sense that a single-point leak would not cause mixing of heat-transfer fluids. This particular heat exchanger is intended to be part of the temperature-regulation system for habitable modules of the International Space Station and to function with water and ammonia as the heat-transfer fluids. The basic fault-tolerant design is adaptable to other heat-transfer fluids and heat exchangers for applications in which mixing of heat-transfer fluids would pose toxic, explosive, or other hazards: Examples could include fuel/air heat exchangers for thermal management on aircraft, process heat exchangers in the cryogenic industry, and heat exchangers used in chemical processing. The reason this heat exchanger can tolerate a single-point leak is that the heat-transfer fluids are everywhere separated by a vented volume and at least two seals. The combination of fault tolerance, compactness, and light weight is implemented in a unique heat-exchanger core configuration: Each fluid passage is entirely surrounded by a vented region bridged by solid structures through which heat is conducted between the fluids. Precise, proprietary fabrication techniques make it possible to manufacture the vented regions and heat-conducting structures with very small dimensions to obtain a very large coefficient of heat transfer between the two fluids. A large heat-transfer coefficient favors compact design by making it possible to use a relatively small core for a given heat-transfer rate. Calculations and experiments have shown that in most respects, the fault-tolerant heat exchanger can be expected to equal or exceed the performance of the non-fault-tolerant heat exchanger that it is intended to supplant (see table). The only significant disadvantages are a slight weight penalty and a small decrease in the mass-specific heat transfer.

Izenson, Michael G.; Crowley, Christopher J.

2005-01-01

335

Fault Diagnosis in HVAC Chillers  

NASA Technical Reports Server (NTRS)

Modern buildings are being equipped with increasingly sophisticated power and control systems with substantial capabilities for monitoring and controlling the amenities. Operational problems associated with heating, ventilation, and air-conditioning (HVAC) systems plague many commercial buildings, often the result of degraded equipment, failed sensors, improper installation, poor maintenance, and improperly implemented controls. Most existing HVAC fault-diagnostic schemes are based on analytical models and knowledge bases. These schemes are adequate for generic systems. However, real-world systems significantly differ from the generic ones and necessitate modifications of the models and/or customization of the standard knowledge bases, which can be labor intensive. Data-driven techniques for fault detection and isolation (FDI) have a close relationship with pattern recognition, wherein one seeks to categorize the input-output data into normal or faulty classes. Owing to the simplicity and adaptability, customization of a data-driven FDI approach does not require in-depth knowledge of the HVAC system. It enables the building system operators to improve energy efficiency and maintain the desired comfort level at a reduced cost. In this article, we consider a data-driven approach for FDI of chillers in HVAC systems. To diagnose the faults of interest in the chiller, we employ multiway dynamic principal component analysis (MPCA), multiway partial least squares (MPLS), and support vector machines (SVMs). The simulation of a chiller under various fault conditions is conducted using a standard chiller simulator from the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE). We validated our FDI scheme using experimental data obtained from different types of chiller faults.

Choi, Kihoon; Namuru, Setu M.; Azam, Mohammad S.; Luo, Jianhui; Pattipati, Krishna R.; Patterson-Hine, Ann

2005-01-01

336

Abstract--Fault collapsing is the process of reducing the number of faults by using redundance and equiva-  

E-print Network

1 Abstract--Fault collapsing is the process of reducing the number of faults by using redundance and equiva- lence/dominance relationships among faults. Exact glo- bal fault collapsing can be easily applied fault collapsing method for library modules that uses both binary deci- sion diagrams and fault

Al-Asaad, Hussain

337

Predeployment validation of fault-tolerant systems through software-implemented fault insertion  

NASA Technical Reports Server (NTRS)

Fault injection-based automated testing (FIAT) environment, which can be used to experimentally characterize and evaluate distributed realtime systems under fault-free and faulted conditions is described. A survey is presented of validation methodologies. The need for fault insertion based on validation methodologies is demonstrated. The origins and models of faults, and motivation for the FIAT concept are reviewed. FIAT employs a validation methodology which builds confidence in the system through first providing a baseline of fault-free performance data and then characterizing the behavior of the system with faults present. Fault insertion is accomplished through software and allows faults or the manifestation of faults to be inserted by either seeding faults into memory or triggering error detection mechanisms. FIAT is capable of emulating a variety of fault-tolerant strategies and architectures, can monitor system activity, and can automatically orchestrate experiments involving insertion of faults. There is a common system interface which allows ease of use to decrease experiment development and run time. Fault models chosen for experiments on FIAT have generated system responses which parallel those observed in real systems under faulty conditions. These capabilities are shown by two example experiments each using a different fault-tolerance strategy.

Czeck, Edward W.; Siewiorek, Daniel P.; Segall, Zary Z.

1989-01-01

338

An Approach to Fault Modeling and Fault Seeding Using the Program Dependence Graph  

E-print Network

We present a fault-classification scheme and a fault-seeding method that are based on the manifestation of faults in the program dependence graph (PDG). We enhance the domain/computation fault-classification scheme developed by Howden to further characterize faults as structural and statement-level, depending on the differences between the PDG for the original program and the PDG for the faulty program. We perform transformations on the PDG to produce the different types of faults described in our PDG-based fault-classification scheme. To demonstrate the usefulness of our technique, we implemented a fault seeder to embed faults in C programs. Our fault seeder makes controlled fault transformations to the PDG for a C program, and generates C code from the transformed PDG. The current version of the fault seeder creates multiple fault-seeded versions of the original program, each with one known fault. To demonstrate the operation of the fault seeder, we used it to perform a study o...

Mary Jean Harrold; A. Jefferson Offutt; Kanupriya Tewary

1994-01-01

339

Novel neural networks-based fault tolerant control scheme with fault alarm.  

PubMed

In this paper, the problem of adaptive active fault-tolerant control for a class of nonlinear systems with unknown actuator fault is investigated. The actuator fault is assumed to have no traditional affine appearance of the system state variables and control input. The useful property of the basis function of the radial basis function neural network (NN), which will be used in the design of the fault tolerant controller, is explored. Based on the analysis of the design of normal and passive fault tolerant controllers, by using the implicit function theorem, a novel NN-based active fault-tolerant control scheme with fault alarm is proposed. Comparing with results in the literature, the fault-tolerant control scheme can minimize the time delay between fault occurrence and accommodation that is called the time delay due to fault diagnosis, and reduce the adverse effect on system performance. In addition, the FTC scheme has the advantages of a passive fault-tolerant control scheme as well as the traditional active fault-tolerant control scheme's properties. Furthermore, the fault-tolerant control scheme requires no additional fault detection and isolation model which is necessary in the traditional active fault-tolerant control scheme. Finally, simulation results are presented to demonstrate the efficiency of the developed techniques. PMID:25014982

Shen, Qikun; Jiang, Bin; Shi, Peng; Lim, Cheng-Chew

2014-11-01

340

Deformation associated with continental normal faults  

NASA Astrophysics Data System (ADS)

Deformation associated with normal fault earthquakes and geologic structures provide insights into the seismic cycle as it unfolds over time scales from seconds to millions of years. Improved understanding of normal faulting will lead to more accurate seismic hazard assessments and prediction of associated structures. High-precision aftershock locations for the 1995 Kozani-Grevena earthquake (Mw 6.5), Greece image a segmented master fault and antithetic faults. This three-dimensional fault geometry is typical of normal fault systems mapped from outcrop or interpreted from reflection seismic data and illustrates the importance of incorporating three-dimensional fault geometry in mechanical models. Subsurface fault slip associated with the Kozani-Grevena and 1999 Hector Mine (Mw 7.1) earthquakes is modeled using a new method for slip inversion on three-dimensional fault surfaces. Incorporation of three-dimensional fault geometry improves the fit to the geodetic data while honoring aftershock distributions and surface ruptures. GPS Surveying of deformed bedding surfaces associated with normal faulting in the western Grand Canyon reveals patterns of deformation that are similar to those observed by interferometric satellite radar interferometry (InSAR) for the Kozani Grevena earthquake with a prominent down-warp in the hanging wall and a lesser up-warp in the footwall. However, deformation associated with the Kozani-Grevena earthquake extends ˜20 km from the fault surface trace, while the folds in the western Grand Canyon only extend 500 m into the footwall and 1500 m into the hanging wall. A comparison of mechanical and kinematic models illustrates advantages of mechanical models in exploring normal faulting processes including incorporation of both deformation and causative forces, and the opportunity to incorporate more complex fault geometry and constitutive properties. Elastic models with antithetic or synthetic faults or joints in association with a master normal fault illustrate how these secondary structures influence the deformation in ways that are similar to fault/fold geometry mapped in the western Grand Canyon. Specifically, synthetic faults amplify hanging wall bedding dips, antithetic faults reduce dips, and joints act to localize deformation. The distribution of aftershocks in the hanging wall of the Kozani-Grevena earthquake suggests that secondary structures may accommodate strains associated with slip on a master fault during postseismic deformation.

Resor, Phillip G.

341

Geologic map + fault mechanics problem set  

NSDL National Science Digital Library

This exercise requires students to answer some questions about stress and fault mechanics that relate to geologic maps. In part A) students must draw a cross section and Mohr circles and make some calculations to explain the slip history and mechanics of two generations of normal faults. In part B) students interpret the faulting history and fault mechanics of the Yerington District, Nevada, based on a classic geologic map and cross section by John Proffett. keywords: geologic map, cross section, normal faults, Mohr circle, Coulomb failure, Andersonian theory, frictional sliding, Byerlee's law

Singleton, John

342

An improved distributed Bayesian algorithm for fault-tolerant detection in electromagnetic spectrum monitoring sensor networks  

Microsoft Academic Search

Electromagnetic spectrum monitoring sensor networks (ESMSNs) have become a new distributed solution for the electromagnetic spectrum monitoring and attracted a large scholars' attention due to its better detection performance. However, the detection performance of ESMSNs will decrease rapidly when the faults occur to the monitoring sensor nodes, which result from the node device itself and the harsh or hostile environment

Zhang Yu; Zhao Hangsheng; Liu Qiongli

2011-01-01

343

Earthquake nucleation on faults with rate-and state-dependent strength  

USGS Publications Warehouse

Dieterich, J.H., 1992. Earthquake nucleation on faults with rate- and state-dependent strength. In: T. Mikumo, K. Aki, M. Ohnaka, L.J. Ruff and P.K.P. Spudich (Editors), Earthquake Source Physics and Earthquake Precursors. Tectonophysics, 211: 115-134. Faults with rate- and state-dependent constitutive properties reproduce a range of observed fault slip phenomena including spontaneous nucleation of slip instabilities at stresses above some critical stress level and recovery of strength following slip instability. Calculations with a plane-strain fault model with spatially varying properties demonstrate that accelerating slip precedes instability and becomes localized to a fault patch. The dimensions of the fault patch follow scaling relations for the minimum critical length for unstable fault slip. The critical length is a function of normal stress, loading conditions and constitutive parameters which include Dc, the characteristic slip distance. If slip starts on a patch that exceeds the critical size, the length of the rapidly accelerating zone tends to shrink to the characteristic size as the time of instability approaches. Solutions have been obtained for a uniform, fixed-patch model that are in good agreement with results from the plane-strain model. Over a wide range of conditions, above the steady-state stress, the logarithm of the time to instability linearly decreases as the initial stress increases. Because nucleation patch length and premonitory displacement are proportional to Dc, the moment of premonitory slip scales by D3c. The scaling of Dc is currently an open question. Unless Dc for earthquake faults is significantly greater than that observed on laboratory faults, premonitory strain arising from the nucleation process for earthquakes may by too small to detect using current observation methods. Excluding the possibility that Dc in the nucleation zone controls the magnitude of the subsequent earthquake, then the source dimensions of the smallest earthquakes in a region provide an upper limit for the size of the nucleation patch. ?? 1992.

Dieterich, J.H.

1992-01-01

344

Model-Based Fault Tolerant Control  

NASA Technical Reports Server (NTRS)

The Model Based Fault Tolerant Control (MBFTC) task was conducted under the NASA Aviation Safety and Security Program. The goal of MBFTC is to develop and demonstrate real-time strategies to diagnose and accommodate anomalous aircraft engine events such as sensor faults, actuator faults, or turbine gas-path component damage that can lead to in-flight shutdowns, aborted take offs, asymmetric thrust/loss of thrust control, or engine surge/stall events. A suite of model-based fault detection algorithms were developed and evaluated. Based on the performance and maturity of the developed algorithms two approaches were selected for further analysis: (i) multiple-hypothesis testing, and (ii) neural networks; both used residuals from an Extended Kalman Filter to detect the occurrence of the selected faults. A simple fusion algorithm was implemented to combine the results from each algorithm to obtain an overall estimate of the identified fault type and magnitude. The identification of the fault type and magnitude enabled the use of an online fault accommodation strategy to correct for the adverse impact of these faults on engine operability thereby enabling continued engine operation in the presence of these faults. The performance of the fault detection and accommodation algorithm was extensively tested in a simulation environment.

Kumar, Aditya; Viassolo, Daniel

2008-01-01

345

Your Mission: (1) Identify 20 active faults in California (2) Identify the direction of fault motion and the slip rate for each fault  

E-print Network

Microsoft Excel to plot a small set of earthquake data Your Supplies: California Faults map handout) of slip for each of the southern California faults that you identified in the table. Each fault is color-coded according to the type and direction of fault Geophysics of Earthquakes Lab 7: California Faults & Seismicity

Smith-Konter, Bridget

346

Multiple Fault Isolation in Redundant Systems  

NASA Technical Reports Server (NTRS)

We consider the problem of sequencing tests to isolate multiple faults in redundant (fault-tolerant) systems with minimum expected testing cost (time). It can be shown that single faults and minimal faults, i.e., minimum number of failures with a failure signature different from the union of failure signatures of individual failures, together with their failure signatures, constitute the necessary information for fault diagnosis in redundant systems. In this paper, we develop an algorithm to find all the minimal faults and their failure signatures. Then, we extend the Sure diagnostic strategies [1] of our previous work to diagnose multiple faults in redundant systems. The proposed algorithms and strategies are illustrated using several examples.

Shakeri, M.; Pattipati, Krishna R.; Raghavan, V.; Patterson-Hine, Ann; Iverson, David L.

1997-01-01

347

Alp Transit: Crossing Faults 44 and 49  

NASA Astrophysics Data System (ADS)

This paper describes the crossing of faults 44 and 49 when constructing the 57 km Gotthard base tunnel of the Alp Transit project. Fault 44 is a permeable fault that triggered significant surface deformations 1,400 m above the tunnel when it was reached by the advancing excavation. The fault runs parallel to the downstream face of the Nalps arch dam. Significant deformations were measured at the dam crown. Fault 49 is sub-vertical and permeable, and runs parallel at the upstream face of the dam. It was necessary to assess the risk when crossing fault 49, as a limit was put on the acceptable dam deformation for structural safety. The simulation model, forecasts and action decided when crossing over the faults are presented, with a brief description of the tunnel, the dam, and the monitoring system.

El Tani, M.; Bremen, R.

2014-05-01

348

Parallel fault-tolerant robot control  

NASA Technical Reports Server (NTRS)

A shared memory multiprocessor architecture is used to develop a parallel fault-tolerant robot controller. Several versions of the robot controller are developed and compared. A robot simulation is also developed for control observation. Comparison of a serial version of the controller and a parallel version without fault tolerance showed the speedup possible with the coarse-grained parallelism currently employed. The performance degradation due to the addition of processor fault tolerance was demonstrated by comparison of these controllers with their fault-tolerant versions. Comparison of the more fault-tolerant controller with the lower-level fault-tolerant controller showed how varying the amount of redundant data affects performance. The results demonstrate the trade-off between speed performance and processor fault tolerance.

Hamilton, D. L.; Bennett, J. K.; Walker, I. D.

1992-01-01

349

PUBLISHER'S NOTE: Rapid Communications Rapid Communications  

NASA Astrophysics Data System (ADS)

As part of a general review of Superconductor Science and Technology, we have been examining the scope for Rapid Communications (RAPs). We recognize these articles make up an important part of the journal representing the latest state-of-the-art research in superconductivity. To reflect this, we have devised a new scope for this article type: 'Rapid Communications. The journal offers open access to outstanding short articles (no longer than 5 journal pages or 4500 words including figures) reporting new and timely developments in superconductivity and its applications. These articles should report very substantial new advances in superconductivity to the readers of Superconductor Science and Technology, but are not expected to meet any requirement of 'general interest'. RAPs will be processed quickly (average receipt to online publication for RAPs is around 60 days) and are permanently free to read in the electronic journal. Authors submitting a RAP should provide reasons why the work is urgent and requires rapid publication. Each RAP will be assessed for suitability by our Reviews and Rapid Communications Editor before full peer review takes place.' The essential points are: They should report very substantial new advances in superconductivity and its application; They must be no longer than 5 journal pages long (approx. 4500 words); Average publication time for a Rapid Communication is 60 days; They are free to read. As mentioned in the previous publisher's announcement (2009 Supercond. Sci. Technol. 22 010101), each submitted Rapid Communication must come with a letter justifying why it should be prioritized over regular papers and will be pre-assessed by our Reviews and Rapid Communications Editor. In addition, we will work with the authors of any Rapid Communication to promote and raise the visibility of the work presented in it. We will be making further changes to the journal in the near future and we write to you accordingly. Thank you for your kind attention and I look forward to receiving your next Rapid Communication.

Miller, Tom

2009-09-01

350

Has the San Gabriel fault been offset  

SciTech Connect

The San Gabriel fault (SGF) in southern California is a right-lateral, strike-slip fault extending for 85 mi in an arcuate, southwestward-bowing curve from near the San Andreas fault at Frazier Mountain to its intersection with the left-lateral San Antonio Canyon fault (SACF) in the eastern San Gabriel Mountains. Termination of the SGF at the presently active SACF is abrupt and prompts the question Has the San Gabriel Fault been offset. Tectonic and geometric relationships in the area suggest that the SGF has been offset approximately 6 mi in a left-lateral sense and that the offset continuation of the SGF, across the SACF, is the right-lateral, strike-slip San Jacinto fault (SJF), which also terminates at the SACF. Reversing the left-lateral movement on the SACF to rejoin the offset ends of the SGF and SJF reveals a fault trace that is remarkably similar in geometry and movement (and perhaps in tectonic history), to the trace of the San Andreas fault through the southern part of the San Bernardino Mountains. The relationship of the Sierra Madre-Cucamonga fault system to the restored SGF-SJF fault is strikingly similar to the relationship of the Banning fault to the Mission Creek-Mill Creek portion of the San Andreas fault. Structural relations suggest that the San Gabriel-San Jacinto system predates the San Andreas fault in the eastern San Gabriel Mountains and that continuing movement on the SACF is currently affecting the trace of the San Andreas fault in the Cajon Pass area.

Sheehan, J.R.

1988-03-01

351

Fault reactivation and fluid flow along a previously dormant normal fault in the northern North Sea  

NASA Astrophysics Data System (ADS)

Detailed seismic imaging and in situ stress and pore-pressure measurements are used to analyze reverse-fault reactivation of a long-dormant normal fault in the northern North Sea. Fault reactivation is caused by three factors: (1) a recent increase in the compressional stress in the area associated with postglacial rebound, (2) locally elevated pore pressure due to the presence of natural gas in a hydrocarbon reservoir on the footwall side of the fault, and (3) a fault orientation that is nearly optimally oriented for frictional slip in the present-day stress field. We demonstrate that the combination of these three factors induces fault slippage and gas leakage along sections of the previously sealing reservoir-bounding fault. We argue that similar pore-pressure triggering of fault slip in the crust may occur because of the accumulation of gas columns of, e.g., CO2 and He in the vicinity of tectonic faults.

Wiprut, David; Zoback, Mark D.

2000-07-01

352

Knowledge acquisition and rapid protyping of an expert system: Dealing with real world problems  

NASA Technical Reports Server (NTRS)

The knowledge engineering and rapid prototyping phases of an expert system that does fault handling for a Solid Amine, Water Desorbed CO2 removal assembly for the Environmental Control and Life Support System for space based platforms are addressed. The knowledge acquisition phase for this project was interesting because it could not follow the textbook examples. As a result of this, a variety of methods were used during the knowledge acquisition task. The use of rapid prototyping and the need for a flexible prototype suggested certain types of knowledge representation. By combining various techniques, a representative subset of faults and a method for handling those faults was achieved. The experiences should prove useful for developing future fault handling expert systems under similar constraints.

Bailey, Patrick A.; Doehr, Brett B.

1988-01-01

353

The susitna glacier thrust fault: Characteristics of surface ruptures on the fault that initiated the 2002 denali fault earthquake  

USGS Publications Warehouse

The 3 November 2002 Mw 7.9 Denali fault earthquake sequence initiated on the newly discovered Susitna Glacier thrust fault and caused 48 km of surface rupture. Rupture of the Susitna Glacier fault generated scarps on ice of the Susitna and West Fork glaciers and on tundra and surficial deposits along the southern front of the central Alaska Range. Based on detailed mapping, 27 topographic profiles, and field observations, we document the characteristics and slip distribution of the 2002 ruptures and describe evidence of pre-2002 ruptures on the fault. The 2002 surface faulting produced structures that range from simple folds on a single trace to complex thrust-fault ruptures and pressure ridges on multiple, sinuous strands. The deformation zone is locally more than 1 km wide. We measured a maximum vertical displacement of 5.4 m on the south-directed main thrust. North-directed backthrusts have more than 4 m of surface offset. We measured a well-constrained near-surface fault dip of about 19?? at one site, which is considerably less than seismologically determined values of 35??-48??. Surface-rupture data yield an estimated magnitude of Mw 7.3 for the fault, which is similar to the seismological value of Mw 7.2. Comparison of field and seismological data suggest that the Susitna Glacier fault is part of a large positive flower structure associated with northwest-directed transpressive deformation on the Denali fault. Prehistoric scarps are evidence of previous rupture of the Sustina Glacier fault, but additional work is needed to determine if past failures of the Susitna Glacier fault have consistently induced rupture of the Denali fault.

Crone, A. J.; Personius, S. F.; Craw, P. A.; Haeussler, P. J.; Staft, L. A.

2004-01-01

354

Constraints on the stress state of the San Andreas Fault with analysis based on core and cuttings from San Andreas Fault Observatory at Depth (SAFOD) drilling phases 1 and 2  

USGS Publications Warehouse

Analysis of field data has led different investigators to conclude that the San Andreas Fault (SAF) has either anomalously low frictional sliding strength (?? 0.6). Arguments for the apparent weakness of the SAF generally hinge on conceptual models involving intrinsically weak gouge or elevated pore pressure within the fault zone. Some models assert that weak gouge and/or high pore pressure exist under static conditions while others consider strength loss or fluid pressure increase due to rapid coseismic fault slip. The present paper is composed of three parts. First, we develop generalized equations, based on and consistent with the Rice (1992) fault zone model to relate stress orientation and magnitude to depth-dependent coefficient of friction and pore pressure. Second, we present temperature-and pressure-dependent friction measurements from wet illite-rich fault gouge extracted from San Andreas Fault Observatory at Depth (SAFOD) phase 1 core samples and from weak minerals associated with the San Andreas Fault. Third, we reevaluate the state of stress on the San Andreas Fault in light of new constraints imposed by SAFOD borehole data. Pure talc (?????0.1) had the lowest strength considered and was sufficiently weak to satisfy weak fault heat flow and stress orientation constraints with hydrostatic pore pressure. Other fault gouges showed a systematic increase in strength with increasing temperature and pressure. In this case, heat flow and stress orientation constraints would require elevated pore pressure and, in some cases, fault zone pore pressure in excess of vertical stress. Copyright 2009 by the American Geophysical Union.

Tembe, S.; Lockner, D.; Wong, T. -F.

2009-01-01

355

Perspective View, San Andreas Fault  

NASA Technical Reports Server (NTRS)

The prominent linear feature straight down the center of this perspective view is California's famous San Andreas Fault. The image, created with data from NASA's Shuttle Radar Topography Mission (SRTM), will be used by geologists studying fault dynamics and landforms resulting from active tectonics. This segment of the fault lies west of the city of Palmdale, Calif., about 100 kilometers (about 60 miles) northwest of Los Angeles. The fault is the active tectonic boundary between the North American plate on the right, and the Pacific plate on the left. Relative to each other, the Pacific plate is moving away from the viewer and the North American plate is moving toward the viewer along what geologists call a right lateral strike-slip fault. Two large mountain ranges are visible, the San Gabriel Mountains on the left and the Tehachapi Mountains in the upper right. Another fault, the Garlock Fault lies at the base of the Tehachapis; the San Andreas and the Garlock Faults meet in the center distance near the town of Gorman. In the distance, over the Tehachapi Mountains is California's Central Valley. Along the foothills in the right hand part of the image is the Antelope Valley, including the Antelope Valley California Poppy Reserve. The data used to create this image were acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000.

This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

SRTM uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

Size: Varies in a perspective view Location: 34.70 deg. North lat., 118.57 deg. West lon. Orientation: Looking Northwest Original Data Resolution: SRTM and Landsat: 30 meters (99 feet) Date Acquired: February 16, 2000

2000-01-01

356

Fault Injection Techniques and Tools  

NASA Technical Reports Server (NTRS)

Dependability evaluation involves the study of failures and errors. The destructive nature of a crash and long error latency make it difficult to identify the causes of failures in the operational environment. It is particularly hard to recreate a failure scenario for a large, complex system. To identify and understand potential failures, we use an experiment-based approach for studying the dependability of a system. Such an approach is applied not only during the conception and design phases, but also during the prototype and operational phases. To take an experiment-based approach, we must first understand a system's architecture, structure, and behavior. Specifically, we need to know its tolerance for faults and failures, including its built-in detection and recovery mechanisms, and we need specific instruments and tools to inject faults, create failures or errors, and monitor their effects.

Hsueh, Mei-Chen; Tsai, Timothy K.; Iyer, Ravishankar K.

1997-01-01

357

The evolution of fabric with displacement in natural brittle faults  

NASA Astrophysics Data System (ADS)

In experiments performed at room temperature on gouges, a characteristic clast size distribution (CSD) is produced with increasing strain, and shear localization is documented to begin after few millimetres of sliding. But in natural faults active at depth in the crust, mechanical processes are associated with fluid-rock interactions, which might control the deformation and strength recovery. We aim to investigate the microstructural, geochemical and mineralogical evolution of low-displacement faults with increasing shear strain. The faults (cataclasite- and pseudotachylyte-bearing) are hosted in tonalite and were active at 9-11 km and 250-300°C. The samples were collected on a large glacier-polished outcrop, where major faults (accommodating up to 4300 mm of displacement) exploit pre-existing magmatic joints and are connected by a network of secondary fractures and faults (accommodating up to 500 mm of displacement) breaking intact tonalite. We performed optical and cathodoluminescence (CL) microscope, Scanning Electron Microscope (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Rietveld X-Ray Powder Diffraction and microprobe chemical analysis in deformation zones of secondary faults with various offsets in order to evaluate the transfer of chemical species between dissolution zones and protected zones. Image analysis techniques were applied on SEM-BSE and optical microscope images to compute the CSD in samples, which experienced an increasing amount of strain. The secondary fractures are up to 5 mm thick. Within the first 20 mm of displacement, shear localizes along Y and R1 surfaces and a cataclastic foliation develops. The CSD evolves from a fractal dimension D of 1.3 in fractures without visible displacement to values above 2 after the first 500 mm of displacement. Chemical maps and CL images indicate that the foliation in cataclasite results from the rotation and fragmentation of clasts, with dissolution of quartz and passive concentration of Ti oxides and titanite in the foliation planes. The cataclasites are cemented by pervasive precipitation of K-feldspar plagues and idiomorphic, randomly oriented, epidote and chlorite. We conclude that the textures of these small displacement (< 500 mm) faults are controlled by brittle processes (fracture propagation and cataclastic comminution) similar to those reproduced in friction experiments performed on granite gouge (e.g., Beeler et al., 1996; Logan, 2007). Then progressively, stress driven fluid-rock reactions develop as fracturing and grain size reduction allows the kinetics of these reactions to be more efficient and fracture interconnection allows fluid infiltration. Healing of microfractures and fault rock cementation caused a rapid posteismic recovery of fault strength. References Beeler, N.M., Tullis, T.E., Blanpied, L., Weeks, J.D., 1996. Frictional behaviour of large displacement experimental faults. Journal of Geophysical Research 101, B4, 8697-8715. Logan, J.M., 2007. The progression from damage to localization of displacement observed in laboratory testing of porous rocks, in Lewis, H., and Couples, G.D. (eds.) The relationship between damage and localization. Geological Society of London Special Publication 289, 75-87.

Mittempergher, S.; Di Toro, G.; Gratier, J.; Aretusini, S.; Boullier-Bertrand, A.

2011-12-01

358

Rapid Prototyping: Lessons Learned  

Microsoft Academic Search

Rapid prototyping is a development method that may or may not be e ective in improving software products and process. Assessing the e ectiveness of rapid prototyping requires empirical data. We analyze 39 published and unpublished \\\\real world\\

V. Scott Gordon; James M. Bieman

1995-01-01

359

Illuminating Northern California's Active Faults  

Microsoft Academic Search

Newly acquired light detection and ranging (lidar) topographic data provide a powerful community resource for the study of landforms associated with the plate boundary faults of northern California (Figure 1). In the spring of 2007, GeoEarthScope, a component of the EarthScope Facility construction project funded by the U.S. National Science Foundation, acquired approximately 2000 square kilometers of airborne lidar topographic

Carol S. Prentice; Christopher J. Crosby; Caroline S. Whitehill; J. Ramón Arrowsmith; Kevin P. Furlong; David A. Phillips

2009-01-01

360

Influence of fault trend, fault bends, and fault convergence on shallow structure, geomorphology, and hazards, Hosgri strike-slip fault, offshore central California  

NASA Astrophysics Data System (ADS)

We mapped a ~94-km-long portion of the right-lateral Hosgri Fault Zone from Point Sal to Piedras Blancas in offshore central California using high-resolution seismic reflection profiles, marine magnetic data, and multibeam bathymetry. The database includes 121 seismic profiles across the fault zone and is perhaps the most comprehensive reported survey of the shallow structure of an active strike-slip fault. These data document the location, length, and near-surface continuity of multiple fault strands, highlight fault-zone heterogeneity, and demonstrate the importance of fault trend, fault bends, and fault convergences in the development of shallow structure and tectonic geomorphology. The Hosgri Fault Zone is continuous through the study area passing through a broad arc in which fault trend changes from about 338° to 328° from south to north. The southern ~40 km of the fault zone in this area is more extensional, resulting in accommodation space that is filled by deltaic sediments of the Santa Maria River. The central ~24 km of the fault zone is characterized by oblique convergence of the Hosgri Fault Zone with the more northwest-trending Los Osos and Shoreline Faults. Convergence between these faults has resulted in the formation of local restraining and releasing fault bends, transpressive uplifts, and transtensional basins of varying size and morphology. We present a hypothesis that links development of a paired fault bend to indenting and bulging of the Hosgri Fault by a strong crustal block translated to the northwest along the Shoreline Fault. Two diverging Hosgri Fault strands bounding a central uplifted block characterize the northern ~30 km of the Hosgri Fault in this area. The eastern Hosgri strand passes through releasing and restraining bends; the releasing bend is the primary control on development of an elongate, asymmetric, "Lazy Z" sedimentary basin. The western strand of the Hosgri Fault Zone passes through a significant restraining bend and dies out northward where we propose that its slip transfers to active structures in the Piedras Blancas fold belt. Given the continuity of the Hosgri Fault Zone through our study area, earthquake hazard assessments should incorporate a minimum rupture length of 110 km. Our data do not constrain lateral slip rates on the Hosgri, which probably vary along the fault (both to the north and south) as different structures converge and diverge but are likely in the geodetically estimated range of 2 to 4 mm/yr. More focused mapping of lowstand geomorphic features (e.g., channels, paleoshorelines) has the potential to provide better constraints. The post-Last-Glacial Maximum unconformity is an important surface for constraining vertical deformation, yielding local fault offset rates that may be as high as 1.4 mm/yr and off-fault deformation rates as high as 0.5 mm/yr. These vertical rates are short-term and not sustainable over longer geologic time, emphasizing the complex evolution and dynamics of strike-slip zones.

Johnson, S. Y.; Watt, J. T.; Hartwell, S. R.

2012-12-01

361

Building the GEM Faulted Earth database  

NASA Astrophysics Data System (ADS)

The GEM Faulted Earth project is aiming to build a global active fault and seismic source database with a common set of strategies, standards, and formats, to be placed in the public domain. Faulted Earth is one of five hazard global components of the Global Earthquake Model (GEM) project. A key early phase of the GEM Faulted Earth project is to build a database which is flexible enough to capture existing and variable (e.g., from slow interplate faults to fast subduction interfaces) global data, and yet is not too onerous to enter new data from areas where existing databases are not available. The purpose of this talk is to give an update on progress building the GEM Faulted Earth database. The database design conceptually has two layers, (1) active faults and folds, and (2) fault sources, and automated processes are being defined to generate fault sources. These include the calculation of moment magnitude using a user-selected magnitude-length or magnitude-area scaling relation, and the calculation of recurrence interval from displacement divided by slip rate, where displacement is calculated from moment and moment magnitude. The fault-based earthquake sources defined by the Faulted Earth project will then be rationalised with those defined by the other GEM global components. A web based tool is being developed for entering individual faults and folds, and fault sources, and includes capture of additional information collected at individual sites, as well as descriptions of the data sources. GIS shapefiles of individual faults and folds, and fault sources will also be able to be uploaded. A data dictionary explaining the database design rationale, definitions of the attributes and formats, and a tool user guide is also being developed. Existing national databases will be uploaded outside of the fault compilation tool, through a process of mapping common attributes between the databases. Regional workshops are planned for compilation in areas where existing databases are not available, or require further population, and will include training on using the fault compilation tool. The tool is also envisaged as an important legacy of the GEM Faulted Earth project, to be available for use beyond the end of the 2 year project.

Litchfield, N. J.; Berryman, K. R.; Christophersen, A.; Thomas, R. F.; Wyss, B.; Tarter, J.; Pagani, M.; Stein, R. S.; Costa, C. H.; Sieh, K. E.

2011-12-01

362

Fault detection using genetic programming  

NASA Astrophysics Data System (ADS)

Genetic programming (GP) is a stochastic process for automatically generating computer programs. GP has been applied to a variety of problems which are too wide to reasonably enumerate. As far as the authors are aware, it has rarely been used in condition monitoring (CM). In this paper, GP is used to detect faults in rotating machinery. Featuresets from two different machines are used to examine the performance of two-class normal/fault recognition. The results are compared with a few other methods for fault detection: Artificial neural networks (ANNs) have been used in this field for many years, while support vector machines (SVMs) also offer successful solutions. For ANNs and SVMs, genetic algorithms have been used to do feature selection, which is an inherent function of GP. In all cases, the GP demonstrates performance which equals or betters that of the previous best performing approaches on these data sets. The training times are also found to be considerably shorter than the other approaches, whilst the generated classification rules are easy to understand and independently validate.

Zhang, Liang; Jack, Lindsay B.; Nandi, Asoke K.

2005-03-01

363

A Log-Scaling Fault Tolerant Agreement Algorithm for a Fault Tolerant MPI  

SciTech Connect

The lack of fault tolerance is becoming a limiting factor for application scalability in HPC systems. The MPI does not provide standardized fault tolerance interfaces and semantics. The MPI Forum's Fault Tolerance Working Group is proposing a collective fault tolerant agreement algorithm for the next MPI standard. Such algorithms play a central role in many fault tolerant applications. This paper combines a log-scaling two-phase commit agreement algorithm with a reduction operation to provide the necessary functionality for the new collective without any additional messages. Error handling mechanisms are described that preserve the fault tolerance properties while maintaining overall scalability.

Hursey, Joshua J [ORNL; Naughton, III, Thomas J [ORNL; Vallee, Geoffroy R [ORNL; Graham, Richard L [ORNL

2011-01-01

364

Evidence for Late Oligocene-Early Miocene episode of transtension along San Andreas Fault system in central California  

SciTech Connect

The San Andreas is one of the most intensely studied fault systems in the world, but many aspects of its kinematic history remain controversial. For example, the period from the late Eocene to early Miocene is widely believed to have been a time of negligible strike-slip movement along the San Andreas fault proper, based on the rough similarity of offset of the Eocene Butano-Point of rocks Submarine Fan, the early Miocene Pinnacles-Neenach volcanic center, and an early Miocene shoreline in the northern Gabilan Range and San Emigdio Mountains. Nonetheless, evidence indicates that a late Oligocene-early Miocene episode of transtension, or strike-slip motion with a component of extension, occurred within the San Andreas fault system. The evidence includes: (1) about 22-24 Ma, widespread, synchronous volcanic activity occurred at about 12 volcanic centers along a 400-km long segment of the central California coast; (2) most of these volcanic centers are located along faults of the San Andreas system, including the San Andreas fault proper, the San Gregorio-Hosgri fault, and the Zayante-Vergeles fault, suggesting that these and other faults were active and served as conduits for magmas rising from below; (3) during the late Oligocene and early Miocene, a pull-apart basin developed adjacent to the San Andreas fault proper in the La Honda basin near Santa Cruz; and (4) during the late Oligocene and early Miocene, active faulting, rapid subsidence, and marine transgression occurred in the La Honda and other sedimentary basins in central California. The amount of right-lateral displacement along the San Andreas fault proper during this transtentional episode is unknown but was probably about 7.5-35 km, based on model studies of pull-apart basin formation. This small amount of movement is well within the range of error in published estimates of the offset of the Eocene to early Miocene geologic features noted.

Stanley, R.G.

1986-04-01

365

Geometric models of faulting at Yucca Mountain  

SciTech Connect

Yucca Mountain, Nevada, is currently being studied as a potential site for a geologic repository of high-level radioactive waste. Alternative conceptual tectonic models are expected to be used by the US Department of Energy (DOE) to fulfill part of the requirement of 10 CFR Part 60 to describe and assess subsurface conditions, and to evaluate conditions that may be potentially favorable or adverse to effective waste isolation. Effective assessment of risk due to geologic hazards such as fault rupture, earthquake seismicity, and volcanic eruptions will involve the use of tectonic and structural geologic models of Yucca Mountain. Estimation of the effects of fault movement and associated distributed deformation on fracture patterns, and potential concomitant changes in bulk hydrogeologic properties, requires knowledge of fault geometry and displacement. Yucca Mountain is located in a tectonically active region, and has a recent geological history of extensional tectonic deformation. Geometric models of faults at Yucca Mountain, as described in this paper, suggest that individual fault segments may be curved at depth and flatten into a regional low-angle detachment fault surface at a depth of approximately 7 to 8 kms. Magnitude and recurrence of earthquake seismicity in the Great Basin region is strongly dependent on fault geometry. Discrimination between planar and listric fault styles is critical to assessment of earthquake seismic risk. The modeled fault system suggests that distributive displacement is probably characteristic of the Yucca Mountain fault system.

Young, S.R. [Southwest Research Inst., San Antonio, TX (US). Center for Nuclear Waste Regulatory Analyses; Stirewalt, G.L. [Southwest Research Inst., Arlington, VA (US). Center for Nuclear Waste Regulatory Analyses; Morris, A.P. [Univ. of Texas, San Antonio, TX (US). Div. of Earth and Physical Sciences

1993-09-01

366

Is the fault core-damage zone model representative of seismogenic faults? Pre-existing anisotropies and fault zone complexity  

NASA Astrophysics Data System (ADS)

Seismogenic fault zones are often described in terms of a "fault core" surrounded by an intensely fractured "damage zone". This useful framework has found broad application in many fault zone studies (hydraulic potential, etc.). However, we found it difficult to apply this model in the case of several seismogenic faults zones hosted in the continental crust of the Italian Southern Alps. As an example, we present quantitative field data (e.g. roughness analysis, fracture density profiles) derived from various digital mapping methods (LiDAR, RTK-GPS, high resolution photogrammetry) to illustrate two case studies of seismogenic strike-slip faults: 1) The Gole Larghe Fault Zone (GLFZ) hosted in granitoids and exhumed from 8-10 km depth, and, 2) The Borcola Pass Fault Zone (BPFZ) hosted in dolostones and exhumed from 1.5-2 km depth. Ancient seismicity is corroborated by the occurrence of pseudotachylytes (GLFZ) and fluidized cataclasites (BPFZ). Both of the studied fault zones accommodated < 2 km of displacement. Despite the large differences in exhumation depth and host rock lithology, both fault zones: 1) are up to several hundreds of meters thick; 2) consist of tens to hundreds of sub-parallel fault strands, connected by a network of minor faults and fractures; 3) most significantly, lack a well-defined fault core that accommodated a majority of fault displacement. Instead, displacement was distributed amongst the networks of minor faults and fractures. The above similarities can be explained by the fact that both fault zones developed in rock volumes containing strong pre-existing anisotropies: magmatic cooling joints sets spaced 2-5 m apart for the GLFZ, regional joint sets spaced < 1 m apart for the BPFZ. During initial development of both fault zones, the pre-existing anisotropies were diffusely reactivated over wide volumes. This was associated in both cases with extensive fluid flow, and sealing/hardening of the pre-existing anisotropies by syn-deformation mineral precipitation. Pre-existing anisotropies are a common occurrence in the continental crust (e.g. joints, bedding surfaces, old fault zones, cleavage surfaces): fault zones developing in such areas will be highly segmented and discontinuous, particularly during the early stages of fault evolution (first few kilometers of displacement?). We speculate that the absence of a leading fault may result in long duration earthquake sequences with several main shocks, especially if accompanied by fluid migration. This is the case for the L'Aquila 2008-2009 seismic sequence (mainshock Mw 6.3) occurring within a fault zone with ~1.5 km total displacement cutting limestones and dolostones (Chiaraluce et al. 2011). High-resolution aftershock locations suggest the re-activation of both optimally and non-optimally oriented small fault segments over a total fault zone width of ~1 km. The magnitude of aftershocks is consistent with activation of fault strands tens to hundreds of meters in length for a period of several months following the mainshocks.

Di Toro, G.; Smith, S. A.; Fondriest, M.; Bistacchi, A.; Nielsen, S. B.; Mitchell, T. M.; Mittempergher, S.; Griffith, W. A.

2012-12-01

367

Fault imprint in clay units: magnetic fabric, structural and mineralogical signature  

NASA Astrophysics Data System (ADS)

Fault-induced deformations in clay units can be difficult to decipher because strain markers are not always visible at outcrop scale or using geophysical methods. Previous studies have indicated that the anisotropy of magnetic susceptibility (ASM) provides a powerful and rapid technique to investigate tectonic deformation in clay units even when they appear quite homogenous and undeformed at the outcrop scale (Lee et al. 1990, Mattei et al. 1997). We report here a study based on ASM, structural analysis and magnetic and clay mineralogy from two boreholes (TF1 and ASM1)drilled horizontally in the Experimental Station of Tournemire of the Institute for Radiological Protection and Nuclear Safety (IRSN) in Aveyron (France). The boreholes intersect a N-S trending strike-slip fault from west to east. The ASM study indicates the evolution of the magnetic fabric from the undeformed host rock to the fault core. Also, all the fractures cutting the studied interval of the core have been measured as well as the slip vectors which are generally well preserved. In the two boreholes, the undeformed sediments outside the fault zone are characterized by an oblate fabric, a sub-vertical minimum susceptibility axis (k3) perpendicular to the bedding plane and without magnetic lineation. Within the fault zone, a tilt in the bedding plane has been observed in two boreholes TF1 and ASM1. In addition, in the TF1 core, the fault area presents a tectonic fabric characterized by a triaxial AMS ellipsoid. Moreover, the magnetic lineation increases and k3 switches from a vertical to a sub-horizontal plane. This kind of fabric has not been observed in borehole ASM1. The structural analysis of the individual fractures making the fault zone indicates a complex tectonic history with different imprint in the two fault segments cut by the two boreholes. The large majority of fractures correspond to dextral strike-slip faults but normal and reverse movements were observed and are more or less frequent depending on the borehole. Notably, many fractures are low angle faults (dip<45°) and may bear both strike-slip or normal striae. The mineralogical study based on X-ray diffraction analysis, have pointed out some variations in clay minerals associations nearby the deformed zones that may be the result of fluid circulation along the fault system which is in agreement with the presence of goethite determined by low magnetic temperature measurements. This multi-proxi study, combining ASM, petrostructural and mineralogical approaches has highlighted the heterogeneity of the fault, but also its past role as a drain to fluid circulation.

Moreno, Eva; Homberg, Catherine; Schnyder, Johann; Person, Alain; du Peloux1, Arthur; Dick, Pierre

2014-05-01

368

Development of secondary faults between en echelon, oblique-slip faults: examples from basement controlled, small-fault systems in the Llano Uplift of central Texas  

E-print Network

DEVELOPMENT OF SECONDARY FAULTS BETWEEN EN ECHELON, OBLIQUE-SLIP FAULTS: EXAMPLES FROM BASEMENT CONTROLLED, SMALL-FAULT SYSTEMS IN THE LLANO UPLIFT OF CENTRAL TEXAS A Thesis by HOWARD REIFFERT HEDGCOXE Submitted to the Graduate College... of Texas ASM University in partial fulfilment of the requirements for the degree of MASTER OF SCIENCE August 1987 Major Subject: Geology DEVELOPMENT OF SECONDARY FAULTS BETWEEN EN ECHELON, OBLIQUE-SLIP FAULTS: EXAMPLES FROM BASEMENT CONTROLLED0 SMALL-FAULT...

Hedgcoxe, Howard Reiffert

2012-06-07

369

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

370

California Fault Zone Orphan Borehole Database  

NASA Astrophysics Data System (ADS)

California is tectonically active and has many abandoned boreholes across the state. With information on these boreholes provided by the Division of Oil, Gas, and Geothermal Resources (DOGGR), we have been able to create several interactive maps on Google Earth for a public website and database accessible at: http://www.pmc.ucsc.edu/~rapid/ . These maps locate abandoned and adoptable wells near active quaternary fault traces and are linked to relevant subsurface information. The links on the website include complete histories, logs, lithologies, stratigraphic columns, and casing information (when available). Earthquake scientists may utilize these wells for monitoring subsurface changes prior, during, and after an earthquake in California. The boreholes could be used for the measurements of several subsurface observables, including: repeat temperature logs, stress measurements, geophysical logging, repeat active-source seismic experiments, sampling of mud/ gas/ fluids, long-term monitoring of temperature and pore fluid pressure, passive seismicity, etc. The “Adopt a Well Program” with DOGGR allows the orphaned well to be tested for 90 days without liability then purchased upon approval. With the science of seismology expanding its limits, these boreholes offer the depth necessary to have accurate subsurface data in order to make informed implications about what occurs deep beneath the surface.

Avila, J.; Brodsky, E. E.

2009-12-01

371

Stresses in planar normal faulting: shallow compression caused by fault-plane mismatch  

NASA Astrophysics Data System (ADS)

Shallow horizontal compressive stress often occurs near the top of the hangingwall plate in numerical modelling of planar normal faulting, extending horizontally for up to 14 km from the fault plane. This compression is attributed to a potential downward mismatch between the dips of the opposing fault planes which would rotate differentially if unconstrained to remain in contact. The mismatch is suppressed by downward increasing lithostatic pressure which applies equal but opposite couples to the fault planes forcing them to remain in contact. This gives rise to shallow compression and deep tension on both sides of the fault. The potential mismatch originates partly from differential loading on opposite sides of the fault, but also from the anti-symmetrical shapes of the footwall and hangingwall plates. These two contributions oppose each other in normal faulting but reinforce in reverse faulting. The modelling also reveals large fault-parallel compressive stress adjacent to the footwall. This compression acts as a seal inhibiting fluid flow across the fault and preventing upflow adjacent to the footwall. In contrast, smaller fault-parallel tension adjacent to the hangingwall provides a low pressure channel for upward fluid flow adjacent to the fault, giving rise to a zone of weakness. Strain relief in this weak zone, in response to shallow mismatch compression, may explain the so-called normal fault drag near the top of the hangingwall.

Bott, Martin H. P.

2009-04-01

372

POTENTIAL EFFECTS OF FAULTS ON GROUNDWATER FLOW FOR THE YUCCA FLAT BASIN, NEVADA TEST SITE, NEVADA  

Microsoft Academic Search

The permeability changes resulting from finely comminuted material in fault cores and the fractured and brecciated rock in fault damage zones allows faults to channelize groundwater flow along the plane of the fault. The efficiency of faults as permeability structures depends on fault zone width, fault offset, depth at which the fault developed, type of faulted rock, extent of secondary

R. P. Dickerson; W. Fryer

2009-01-01

373

Perspective View, San Andreas Fault  

NASA Technical Reports Server (NTRS)

The prominent linear feature straight down the center of this perspective view is the San Andreas Fault in an image created with data from NASA's shuttle Radar Topography Mission (SRTM), which will be used by geologists studying fault dynamics and landforms resulting from active tectonics. This segment of the fault lies west of the city of Palmdale, California, about 100 kilometers (about 60 miles) northwest of Los Angeles. The fault is the active tectonic boundary between the North American plate on the right, and the Pacific plate on the left. Relative to each other, the Pacific plate is moving away from the viewer and the North American plate is moving toward the viewer along what geologists call a right lateral strike-slip fault. This area is at the junction of two large mountain ranges, the San Gabriel Mountains on the left and the Tehachapi Mountains on the right. Quail Lake Reservoir sits in the topographic depression created by past movement along the fault. Interstate 5 is the prominent linear feature starting at the left edge of the image and continuing into the fault zone, passing eventually over Tejon Pass into the Central Valley, visible at the upper left.

This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.

Size: Varies in a perspective view Location: 34.78 deg. North lat., 118.75 deg. West lon. Orientation: Looking Northwest Original Data Resolution: SRTM and Landsat: 30 meters (99 feet) Date Acquired: February 16, 2000

2000-01-01

374

Holocene fault scarps near Tacoma, Washington, USA  

USGS Publications Warehouse

Airborne laser mapping confirms that Holocene active faults traverse the Puget Sound metropolitan area, northwestern continental United States. The mapping, which detects forest-floor relief of as little as 15 cm, reveals scarps along geophysical lineaments that separate areas of Holocene uplift and subsidence. Along one such line of scarps, we found that a fault warped the ground surface between A.D. 770 and 1160. This reverse fault, which projects through Tacoma, Washington, bounds the southern and western sides of the Seattle uplift. The northern flank of the Seattle uplift is bounded by a reverse fault beneath Seattle that broke in A.D. 900-930. Observations of tectonic scarps along the Tacoma fault demonstrate that active faulting with associated surface rupture and ground motions pose a significant hazard in the Puget Sound region.

Sherrod, B.L.; Brocher, T.M.; Weaver, C.S.; Bucknam, R.C.; Blakely, R.J.; Kelsey, H.M.; Nelson, A.R.; Haugerud, R.

2004-01-01

375

Software reliability through fault-avoidance and fault-tolerance  

NASA Technical Reports Server (NTRS)

The use of back-to-back, or comparison, testing for regression test or porting is examined. The efficiency and the cost of the strategy is compared with manual and table-driven single version testing. Some of the key parameters that influence the efficiency and the cost of the approach are the failure identification effort during single version program testing, the extent of implemented changes, the nature of the regression test data (e.g., random), and the nature of the inter-version failure correlation and fault-masking. The advantages and disadvantages of the technique are discussed, together with some suggestions concerning its practical use.

Vouk, Mladen A.; Mcallister, David F.

1990-01-01

376

The effects of lithology and initial fault angle in physical models of fault-propagation folds  

E-print Network

Experimentally deformed physical rock models are used to examine the effects of changing mechanical stratigraphy and initial fault angle on the development of fault-propagation folds over a flat-ramp-flat thrust geometry. This study also...

McLain, Christopher Thomas

2012-06-07

377

A fault location approach for fuzzy fault section estimation on radial distribution feeders  

E-print Network

Locating the faulted section of a distribution system is a difficult task because of lack of accurate system models and the presence of uncertainty in the data used for estimating the fault section. Many of the methods used to account...

Andoh, Kwame Sarpong

2012-06-07

378

Seismoelectric Imaging of a Shallow Fault System Employing Fault Guided Waves  

E-print Network

. The seismic data revealed dispersive energy packets, indicative of guided waves, within the fault zone and absent in the surrounding lithologies. The seismoelectric data was able to produce comparable signals in the fault zone showing guided waves....

Cohrs, Frelynn Joseph Reese

2012-07-16

379

Realistic fault modeling and quality test generation of combined delay faults  

E-print Network

With increasing operating speed and shrinking technology, timing defects in integrated circuits are becoming increasingly important. The well established stuck-at-fault model is not sufficient because it is a static fault model and does not account...

Thadhlani, Ajaykumar A

2012-06-07

380

Inferred relation of Miocene Bealville Fanglomerate to Edison Fault, Caliente Canyon area, Kern County, California  

SciTech Connect

The Bealville Fanglomerate is a very coarse, local, eastern torrential facies of the middle Tertiary marine sedimentary sequence of southern San Joaquin basin. This fanglomerate is exposed in lower Caliente Canyon east of Bakersfield. It is composed of unsorted boulder-size detritus of granitic rocks now exposed in the highlands on the east and south. The fanglomerate intertongues northwestward into the overlying Miocene fluvial Bena Gravel and probably partly into the underlying Oligocene-Miocene fluvial Walker Formation. In its eastern exposure, the Bealville Fanglomerate laps onto granitic basement. The Bealville Fanglomerate, as thick as 7000 ft (2200 m), dips southward into the north-dipping Edison fault. Pre-Tertiary granitic basement was elevated on the Edison fault to the south when the fault was contemporaneously active during the Miocene. Both the fanglomerate terrane north of the fault and the adjacent granitic basement terrane south of it are now eroded to low relief, so the fault is not expressed physiographically and is inactive. In contrast, the active White Wolf fault to the southeast is expressed by the northwest-facing escarpment slope of Bear Mountain. The Bealville Fanglomerate was deposited during the early and middle Miocene as coarse alluvial detritus on the western base of the rising Sierra Nevada uplift of granitic terrane. This southward-dipping fanglomerate is coarser and thicker than other formations deposited on the eastern margin of the San Joaquin basin. These conditions indicate that the fanglomerate was deposited rapidly on a southward-tilting block against a block of granitic basement being elevated on the Edison fault to the south, and it was derived from the adjacent granitic terrane to the east and from that elevated on the Edison fault to the south.

Dibblee, T.W. Jr.; Warne, A.H.

1986-04-01

381

Effect of strain on the stacking fault energy of copper: A first-principles study  

NASA Astrophysics Data System (ADS)

The intrinsic stacking fault energy (SFE) of copper under volumetric, longitudinal, and shear strains is investigated using density functional theory (GGA-PBE). Calculations are performed using a copper slab model aligned perpendicular to the (111) intrinsic stacking fault plane. The calculated SFE for unstrained copper is ? = 41 mJ/m2. Results show a strong dependence of ? on strain and distinct behavior for different types of strain: (a) volumetric and longitudinal in the direction perpendicular to the stacking fault, (b) longitudinal parallel to the stacking fault, and (c) shear parallel to the stacking fault. In the first case (a), the SFE decreases monotonically with strain with a slope d?/d?|?=0 = -0.44 J/m2 and -0.87 J/m2 for volumetric and longitudinal, respectively, and with d2?/d?2 > 0. In contrast, for longitudinal strain parallel to the stacking fault (b), the SFE dependence exhibits d2?/d?2 < 0 with a maximum at ? ? -0.015. For the case of shear parallel to the stacking fault (c), the SFE is nearly constant at small and moderately large strain, but drops rapidly at very large strain (by a factor of 1/3 for <1¯10>{111} shear at ? = ±0.1). For large <112¯>{111} shear strains, the SFE can either increase or decrease at large strain depending on the sign of the strain. In volumetric or longitudinal (perpendicular to the stacking fault) tension and longitudinal strain in the boundary plane (and for some shear directions), the SFE can become negative, implying a limit on the stability of the fcc crystal structure. The strong dependence of the SFE on strain suggests deep implications for the mechanical properties, microstructural evolution, and dynamic plasticity of metals at high pressure, during severe plastic deformation, and in shock-loading conditions.

Branicio, P. S.; Zhang, J. Y.; Srolovitz, D. J.

2013-08-01

382

Generation and propagation of stick-slip waves over a fault with rate-independent friction  

NASA Astrophysics Data System (ADS)

Earthquakes generated at faults are either produced by rapid (sometimes supersonic) propagation of shear cracks/ruptures along the fault or originated in the stick-slip sliding over the fault. In some cases, supersonic (faster than the shear wave velocity) propagation of earthquake-generating shear ruptures or sliding is observed. This gave rise to the concept of supersonic shear crack propagation, much researched in the literature. Here we consider another mechanisms of supersonic sliding propagation. We concentrate on the stick-slip sliding as the earthquake mechanism. It is conventionally assumed that the mechanism of stick-slip lies in intermittent change between static and kinetic friction and the rate dependence of the friction coefficient. However the accumulation of elastic energy in the sliding plates on both sides of the fault can produce oscillations in the velocity of sliding even if the friction coefficient is constant. These oscillations resemble stick-slip movement, but they manifest themselves in terms of sliding velocity rather than displacement. Furthermore, over long faults the sliding exhibits wave-like propagation. We developed a model that shows that the zones of non-zero sliding velocities propagate along the fault with the velocity of p-wave. The mechanism of such fast movement is in the fact that sliding of every element of the rock at the fault surface creates normal (tensile/compressive) stresses in the neighbouring elements (normal stresses on the planes normal to the fault surface). The strains associated with these stresses are controlled by the Young's modulus rather than shear modulus resulting in the p-wave velocity of propagation of the sliding zone. This results in the observed supersonic (with respect to the s-waves) propagation of the apparent shear rupture. Keywords: Stick-slip, Rate-independent friction, Supersonic propagation.

Karachevtseva, Iuliia; Dyskin, Arcady; Pasternak, Elena

2014-05-01

383

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

384

Hydrogen Embrittlement And Stacking-Fault Energies  

NASA Technical Reports Server (NTRS)

Embrittlement in Ni/Cu alloys appears related to stacking-fault porbabilities. Report describes attempt to show a correlation between stacking-fault energy of different Ni/Cu alloys and susceptibility to hydrogen embrittlement. Correlation could lead to more fundamental understanding and method of predicting susceptibility of given Ni/Cu alloy form stacking-fault energies calculated from X-ray diffraction measurements.

Parr, R. A.; Johnson, M. H.; Davis, J. H.; Oh, T. K.

1988-01-01

385

Evidence for a strong San Andreas fault  

Microsoft Academic Search

Stress measurements in deep boreholes have universally shown that stresses in the Earth's crust are in equilibrium with favorably oriented faults with friction coefficients in the range 0.6-0.7 and with nearly hydrostatic pore-pressure gradients. Because of the lack of any fault-adjacent heat-flow anomaly as predicted by a conductive model of frictional heating, the San Andreas fault has long been thought

Christopher H. Scholz

2000-01-01

386

Transient fault detection via simultaneous multithreading  

Microsoft Academic Search

Smaller feature sizes, reduced voltage levels, higher transistor counts, and reduced noise margins make future generations of microprocessors increasingly prone to transient hardware faults. Most commercial fault-tolerant computers use fully replicated hardware components to detect microprocessor faults. The components are lockstepped (cycle-by-cycle synchronized) to ensure that, in each cycle, they perform the same operation on the same inputs, producing the

Steven K. Reinhardt; Shubhendu S. Mukherjee

2000-01-01

387

Earthquake dynamics on dip-slip faults  

Microsoft Academic Search

Observations of dip-slip earthquakes have indicated that non-vertical geometry is associated with asymmetry in ground motion: thrust\\/reverse faults produce higher ground motion than normal faults, and hanging walls experience higher motion than footwalls. Using two- and three-dimensional computer simulations of fault dynamics, we show that these observations can be explained by the interaction between the free surface and the frictional

David D. Oglesby

1999-01-01

388

Influence of mechanical stratigraphy and kinematics on fault scaling relations  

Microsoft Academic Search

In order to document effects of mechanical anisotropy, fault geometry, and structural style on displacement-length (D-L) scaling relations, we investigated fault dimensions in the lithologically heterogeneous Monterey Formation exposed along Arroyo Burro Beach, California. The faults, which range in length from several centimeters to several meters, group into two populations: small faults confined to individual mudstone beds, and larger faults

Richard J. Behl; G. Gutierrezalonso; Taixu Bai; Michael A. Wacker; Kevin B. Collinsworth

1997-01-01

389

Estimating the distribution of fault latency in a digital processor  

NASA Technical Reports Server (NTRS)

Presented is a statistical approach to measuring fault latency in a digital processor. The method relies on the use of physical fault injection where the duration of the fault injection can be controlled. Although a specific fault's latency period is never directly measured, the method indirectly determines the distribution of fault latency.

Ellis, Erik L.; Butler, Ricky W.

1987-01-01

390

Model Checking and Fault Tolerance Glenn Bruns and Ian Sutherland  

E-print Network

Model Checking and Fault Tolerance Glenn Bruns and Ian Sutherland Bell Labs, Lucent Technologies of fault­tolerant systems. Fault models and fault­handling mechanisms are modelled using special in the application of model checking to fault­tolerant systems. By modelling failures of a system component one can

Bruns, Glenn

391

GIS product reliability analysis based fuzzy fault tree  

Microsoft Academic Search

The paper imports fuzzy fault tree into GIS product reliability analysis for the fist time. The paper discusses how GIS product reliability analysis uses fuzzy fault tree method, mainly researches two problems that is GIS product fuzzy fault tree construction and analysis step of GIS product fuzzy fault tree; uses example to adopt fuzzy fault tree method processing GIS product

Xianfeng Ye; Youjian Hu; Shengwu Hu

2011-01-01

392

Modes of faulting at mid-ocean ridges  

Microsoft Academic Search

Many differences between normal faults generated at fast and slow spreading ridges are recognized. Fast spreading faults show about a tenth the vertical displacement seen for typical faults formed at slow spreading ridges. Essentially all faults mapped at slow spreading ridges dip toward the spreading axis while about 50% of normal faults seen at fast spreading ridges dip away from

R. Buck; L. Lavier; A. Poliakov

2003-01-01

393

Jurassic faults of southwest Alabama and offshore areas  

Microsoft Academic Search

Four fault groups affecting Jurassic strata occur in the southwest and offshore Alabama areas. They include the regional basement rift trend, the regional peripheral fault trend, the Mobile graben fault system, and the Lower Mobile Bay fault system. The regional basement system rift and regional peripheral fault trends are distinct and rim the inner margin of the eastern Gulf Coastal

R. M. Mink; B. H. Tew; B. L. Bearden; E. A. Mancini

1991-01-01

394

Fault tree analysis on handwashing for hygiene management  

Microsoft Academic Search

FTA (fault tree analysis) of the handwashing process was performed to investigate the causes for faults in hygiene management. The causes were deductively identified as the events causing every possible hazard by constructing a fault tree. The fault tree was constructed in a hierarchical structure with a single top event (occurrence of faults in hand washing), seven intermediate events, and

Aeri Park; Seung Ju Lee

2009-01-01

395

COMPLETE FAULT ANALYSIS FOR LONG TRANSMISSION LINE USING  

E-print Network

COMPLETE FAULT ANALYSIS FOR LONG TRANSMISSION LINE USING SYNCHRONIZED SAMPLING Nan Zhang Mladen 77843-3128, U.S.A. Abstract: A complete fault analysis scheme for long transmission line represented for normal situation and external faults, and is close to fault current during the internal faults

396

Syntactic Fault Patterns in OO Programs Roger T. Alexander  

E-print Network

Syntactic Fault Patterns in OO Programs Roger T. Alexander Colorado State University Dept faults are widely studied, there are many aspects of faults that we still do not understand, par is to cause failures and thereby detect faults, a full understanding of the char- acteristics of faults

Offutt, Jeff

397

On-Board Real-Time State and Fault Identification for Rovers  

NASA Technical Reports Server (NTRS)

For extended autonomous operation, rovers must identify potential faults to determine whether its execution needs to be halted or not. At the same time, rovers present particular challenges for state estimation techniques: they are subject to environmental influences that affect senior readings during normal and anomalous operation, and the sensors fluctuate rapidly both because of noise and because of the dynamics of the rover's interaction with its environment. This paper presents MAKSI, an on-board method for state estimation and fault diagnosis that is particularly appropriate for rovers. The method is based on a combination of continuous state estimation, wing Kalman filters, and discrete state estimation, wing a Markov-model representation.

Washington, Richard

2000-01-01

398

EOS, TRANSACTIONS, AMERICAN GEOPHYSICAL UNION Drill Bit Noise Illuminates the San Andreas Fault  

E-print Network

Extracting the vibration response of the subsurface from noise is a rapidly growing field of research [Curtis et al., 2006; Larose et al., 2006]. We carried out broadside imaging of the San Andreas fault zone (SAFZ) using drill bit noise created in the main hole of the San Andreas Fault Observatory at Depth (SAFOD), near Parkfield, Calif. Imaging with drill bit noise is not new, but it traditionally requires the measurement of the vibrations of the drill stem [Rector and Marion, 1991]; such measurements provide the waves radiated by the drill bit. At SAFOD, these measurements were not available due to the absence of

unknown authors

2008-01-01

399

Stable sliding preceding stick-slip on fault surfaces in granite at high pressure  

USGS Publications Warehouse

The distance of stable sliding before sudden slip on fault surfaces in granite decreases rapidly as the confining pressure is increased. At a pressure of 6 kb the amount of stable creep is very small or absent. Two orders of magnitude change in strain rate has no effect on the distance of stable sliding. Our results suggest that in the earth, fault creep should predominate in the shallow crust but in the deep crustal layer most of the stresses are probably relieved by sudden earthquake type of motion. Below the crust high temperature would promote stable-slip so in this region creep would once more predominate. ?? 1975 Birkha??user Verlag.

Byerlee, J. D.; Summers, R.

1975-01-01

400

Seismicity and fault interaction, Southern San Jacinto Fault Zone and adjacent faults, southern California: Implications for seismic hazard  

NASA Astrophysics Data System (ADS)

The southern San Jacinto fault zone is characterized by high seismicity and a complex fault pattern that offers an excellent setting for investigating interactions between distinct faults. This fault zone is roughly outlined by two subparallel master fault strands, the Coyote Creek and Clark-San Felipe Hills faults, that are located 2 to 10 km apart and are intersected by a series of secondary cross faults. Seismicity is intense on both master faults and secondary cross faults in the southern San Jacinto fault zone. The seismicity on the two master strands occurs primarily below 10 km; the upper 10 km of the master faults are now mostly quiescent and appear to rupture mainly or solely in large earthquakes. Our results also indicate that a considerable portion of recent background activity near the April 9, 1968, Borrego Mountain rupture zone (ML=6.4) is located on secondary faults outside the fault zone. We name and describe the Palm Wash fault, a very active secondary structure located about 25 km northeast of Borrego Mountain that is oriented subparallel to the San Jacinto fault system, dips approximately 70° to the northeast, and accommodates right-lateral shear motion. The Vallecito Mountain cluster is another secondary feature delineated by the recent seismicity and is characterized by swarming activity prior to nearby large events on the master strand. The 1968 Borrego Mountain and the April 28, 1969, Coyote Mountain (ML=5.8) events are examples of earthquakes with aftershocks and subevents on these secondary and master faults. Mechanisms from those earthquakes and recent seismic data for the period 1981 to 1986 are not simply restricted to strike-slip motion; dipslip motion is also indicated. Teleseismic body waves (long-period P and SH) of the 1968 and 1969 earthquakes were inverted simultaneously for source mechanism, seismic moment, rupture history, and centroid depth. The complicated waveforms of the 1968 event (Mo=1.2 × 1019 N m) are interpreted in terms of two subevents; the first caused by right-lateral strike-slip motion in the mainshock along the Coyote Creek fault and the second by a rupture located about 25 km away from the master fault. Our waveform inversion of the 1969 event indicates that strike-slip motion predominated, releasing a seismic moment of 2.5 × 1017 N m. Nevertheless, the right-lateral nodal plane of the focal mechanism is significantly misoriented (20°) with respect to the master fault, and hence the event is not likely to be associated with a rupture on that fault. From this and other examples in southern California, we conclude that cross faults may contribute significantly to seismic hazard and that interaction between faults has important implications for earthquake prediction.

Petersen, Mark D.; Seeber, Leonardo; Sykes, Lynn R.; NáB?Lek, John L.; Armbruster, John G.; Pacheco, Javier; Hudnut, Kenneth W.

1991-12-01

401

An algorithm for faulted phase and feeder selection under high impedance fault conditions  

E-print Network

AN ALGORITHM FOR FAULTED PHASE AND FEEDER SELECTION UNDER HIGH IMPEDANCE FAULT CONDITIONS A Thesis by CARL LEE BENNER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1988 Major Subject: Electrical Engineering AN ALGORITHM FOR FAULTED PHASE AND FEEDER SELECTION UNDER HIGH IMPEDANCE FAULT CONDITIONS A Thesis by CARL LEE BENNER Approved as to style and content by: B. Don Russell...

Benner, Carl Lee

2012-06-07

402

Three-dimensional Geology of the Hayward Fault and its Correlation with Fault Behavior, Northern California  

Microsoft Academic Search

Relationships between fault behavior and geology along the Hayward Fault were investigated using a three-dimensional geologic model of the Hayward fault and vicinity. The three-dimensional model, derived from geologic, geophysical, and seismicity data, allowed the construction of a `geologic map' of east- and west-side surfaces, maps that show the distribution of geologic units on either side of the fault that

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

2004-01-01

403

The morphology of strike-slip faults - Examples from the San Andreas Fault, California  

NASA Technical Reports Server (NTRS)

The dilatational strains associated with vertical faults embedded in a horizontal plate are examined in the framework of fault kinematics and simple displacement boundary conditions. Using boundary element methods, a sequence of examples of dilatational strain fields associated with commonly occurring strike-slip fault zone features (bends, offsets, finite rupture lengths, and nonuniform slip distributions) is derived. The combinations of these strain fields are then used to examine the Parkfield region of the San Andreas fault system in central California.

Bilham, Roger; King, Geoffrey

1989-01-01

404

Effects of Physical Fault Properties on Frictional Instabilities Produced on Simulated Faults  

Microsoft Academic Search

U.S. Geological Survey Laboratory studies of large-scale simulated faults show that physical properties of the fault, specifically normal stress and fault roughness, significantly influence the unstable shear failure behavior of the fault. In addition, the experiments provide insights into important length-scaling effects that are useful for assessing concepts such as critical crack length or rupture nucleation dimension. Stick-slip shear failures

Paul G. Okubo; James H. Dieterich

1984-01-01

405

Characterization of the San Andreas Fault near Parkfield, California by fault-zone trapped waves  

Microsoft Academic Search

In October, 2002, coordinated by the Pre-EarthScope\\/SAFOD, we conducted an extensive seismic experiment at the San Andreas fault (SAF), Parkfield to record fault-zone trapped waves generated by explosions and microearthquakes using dense linear seismic arrays of 52 PASSCAL 3-channel REFTEKs deployed across and along the fault zone. We detonated 3 explosions within and out of the fault zone during the

Y. Li; J. Vidale; E. Cochran

2003-01-01

406

Adding intelligence to fuse models for faults  

NASA Astrophysics Data System (ADS)

The SPICE fuse models that are based on theoretical fuse behavior and data derived from faulted fuse tests are presented. An overview of SPICE fault analysis and a brief history of the models' development are included. The limitations of each model and possible methods of overcoming them are examined. The mosty favored model is discussed in more detail. Its major advantages are: (1) the more accurate prediction of the fuse resistance as the fuse element is heated during the fault event; and (2) the capability of the model to know when to blow, based on fuse rating and fault current profile.

Liffring, Mark E.

407

Transtensional structures along a transform fault  

SciTech Connect

Recently acquired side-scan imagery and single-channel seismic profiles along the Fiji transform fault reveal the structures produced by its sinistral motion. The fault extends from Peggy Ridge in the northern Lau basin into the central North Fiji basin, at least as far as the Viwa spreading ridge near Viti Levu, Fiji. A change in character of the fault along its length is evident in the imagery. Adjacent to the Fiji platform, the fault is clearly defined. Deformation and seismicity are confined to a narrow linear band which is offset by two left-stepping relay zones. Farther to the west in the north Fiji basin, however, the fault is not well defined. A series of ridges and basins occurs in a complicated region between 174{degree}E and 177{degree}E. These are produced by interaction of the fault with the nearby spreading centers. Interpretations differ as to the fault and spreading center geometry in this area. The arrangement of the tectonic element has controlled the formation of the observed structures. The intersection of the fault with the Viwa spreading ridge has features typical of ridge-transform insections. Within the complicated area between 174{degree} and 177{degree}E, the ridges and basins are postulated to be a consequence of the fault's shearing motion.

Jarvis, P.A.; Kroenke, L. (Hawaii Institute of Geophysics, Honolulu (USA)); Hughes-Clark, J. (James Cook Univ., Townsville (Australia)); Tiffin, D. (CCOP/SOPAC, Suva (Fiji))

1990-05-01

408

Mantle fault zone beneath Kilauea Volcano, Hawaii.  

PubMed

Relocations and focal mechanism analyses of deep earthquakes (>/=13 kilometers) at Kilauea volcano demonstrate that seismicity is focused on an active fault zone at 30-kilometer depth, with seaward slip on a low-angle plane, and other smaller, distinct fault zones. The earthquakes we have analyzed predominantly reflect tectonic faulting in the brittle lithosphere rather than magma movement associated with volcanic activity. The tectonic earthquakes may be induced on preexisting faults by stresses of magmatic origin, although background stresses from volcano loading and lithospheric flexure may also contribute. PMID:12702874

Wolfe, Cecily J; Okubo, Paul G; Shearer, Peter M

2003-04-18

409

Sequential Test Strategies for Multiple Fault Isolation  

NASA Technical Reports Server (NTRS)

In this paper, we consider the problem of constructing near optimal test sequencing algorithms for diagnosing multiple faults in redundant (fault-tolerant) systems. The computational complexity of solving the optimal multiple-fault isolation problem is super-exponential, that is, it is much more difficult than the single-fault isolation problem, which, by itself, is NP-hard. By employing concepts from information theory and Lagrangian relaxation, we present several static and dynamic (on-line or interactive) test sequencing algorithms for the multiple fault isolation problem that provide a trade-off between the degree of suboptimality and computational complexity. Furthermore, we present novel diagnostic strategies that generate a static diagnostic directed graph (digraph), instead of a static diagnostic tree, for multiple fault diagnosis. Using this approach, the storage complexity of the overall diagnostic strategy reduces substantially. Computational results based on real-world systems indicate that the size of a static multiple fault strategy is strictly related to the structure of the system, and that the use of an on-line multiple fault strategy can diagnose faults in systems with as many as 10,000 failure sources.

Shakeri, M.; Pattipati, Krishna R.; Raghavan, V.; Patterson-Hine, Ann; Kell, T.

1997-01-01

410

Applications of Fault Detection in Vibrating Structures  

NASA Technical Reports Server (NTRS)

Structural fault detection and identification remains an area of active research. Solutions to fault detection and identification may be based on subtle changes in the time series history of vibration signals originating from various sensor locations throughout the structure. The purpose of this paper is to document the application of vibration based fault detection methods applied to several structures. Overall, this paper demonstrates the utility of vibration based methods for fault detection in a controlled laboratory setting and limitations of applying the same methods to a similar structure during flight on an experimental subscale aircraft.

Eure, Kenneth W.; Hogge, Edward; Quach, Cuong C.; Vazquez, Sixto L.; Russell, Andrew; Hill, Boyd L.

2012-01-01

411

Outer Rise Faulting And Mantle Serpentinization  

NASA Astrophysics Data System (ADS)

Dehydration of serpentinized mantle of the downgoing slab has been proposed to cause both intermediate depth earthquakes (50-300 km) and arc volcanism at sub- duction zones. It has been suggested that most of this serpentinization occurs beneath the outer rise; where normal faulting earthquakes due to bending cut > 20 km deep into the lithosphere, allowing seawater to reach and react with underlying mantle. However, little is known about flexural faulting at convergent margins; about how many normal faults cut across the crust and how deeply they penetrate into the man- tle; about the true potential of faults as conduits for fluid flow and how much water can be added through this process. We present evidence that pervasive flexural faulting may cut deep into the mantle and that the amount of faulting vary dramatically along strike at subduction zones. Flexural faulting increases towards the trench axis indicat- ing that active extension occurs in a broad area. Multibeam bathymetry of the Pacific margin of Costa Rica and Nicaragua shows a remarkable variation in the amount of flexural faulting along the incoming ocean plate. Several parameters seem to control lateral variability. Off south Costa Rica thick crust of the Cocos Ridge flexes little, and little to no faulting develops near the trench. Off central Costa Rica, normal thick- ness crust with magnetic anomalies striking oblique to the trench displays small offset faults (~200 m) striking similar to the original seafloor fabric. Off northern Costa Rica, magnetic anomalies strike perpendicular to the trench axis, and a few ~100m-offset faults develop parallel to the trench. Further north, across the Nicaraguan margin, magnetic anomalies strike parallel to the trench and the most widespread faulting de- velops entering the trench. Multichannel seismic reflection images in this area show a pervasive set of trenchward dipping reflections that cross the ~6 km thick crust and extend into the mantle to depths of at least 20 km. Some reflections project updip to offsets in top basement and seafloor, indicating that they are fault plane reflections. Such a deeply penetrating tectonic fabric could have not developed during crustal cre- ation at the paleo-spreading center where the brittle layer is few km thick. Thus, they must be created during flexure of the plate entering the trench. This data imply that deep and widespread serpentinization of the incoming lithosphere can occur when the lithosphere is strongly faulted; that the extent of lithospheric faulting is closely re- lated to the crustal structure of the incoming plate; and that the amount of lithosphere faulting can change dramatically within a hundred km distance along a trench axis.

Ranero, C. R.; Phipps Morgan, J.; McIntosh, K.; Reichert, C.

412

Faults Discovery By Using Mined Data  

NASA Technical Reports Server (NTRS)

Fault discovery in the complex systems consist of model based reasoning, fault tree analysis, rule based inference methods, and other approaches. Model based reasoning builds models for the systems either by mathematic formulations or by experiment model. Fault Tree Analysis shows the possible causes of a system malfunction by enumerating the suspect components and their respective failure modes that may have induced the problem. The rule based inference build the model based on the expert knowledge. Those models and methods have one thing in common; they have presumed some prior-conditions. Complex systems often use fault trees to analyze the faults. Fault diagnosis, when error occurs, is performed by engineers and analysts performing extensive examination of all data gathered during the mission. International Space Station (ISS) control center operates on the data feedback from the system and decisions are made based on threshold values by using fault trees. Since those decision-making tasks are safety critical and must be done promptly, the engineers who manually analyze the data are facing time challenge. To automate this process, this paper present an approach that uses decision trees to discover fault from data in real-time and capture the contents of fault trees as the initial state of the trees.

Lee, Charles

2005-01-01

413

On Identifiability of Bias-Type Actuator-Sensor Faults in Multiple-Model-Based Fault Detection and Identification  

NASA Technical Reports Server (NTRS)

This paper explores a class of multiple-model-based fault detection and identification (FDI) methods for bias-type faults in actuators and sensors. These methods employ banks of Kalman-Bucy filters to detect the faults, determine the fault pattern, and estimate the fault values, wherein each Kalman-Bucy filter is tuned to a different failure pattern. Necessary and sufficient conditions are presented for identifiability of actuator faults, sensor faults, and simultaneous actuator and sensor faults. It is shown that FDI of simultaneous actuator and sensor faults is not possible using these methods when all sensors have biases.

Joshi, Suresh M.

2012-01-01

414

Transform fault earthquakes in the North Atlantic: Source mechanisms and depth of faulting  

NASA Technical Reports Server (NTRS)

The centroid depths and source mechanisms of 12 large earthquakes on transform faults of the northern Mid-Atlantic Ridge were determined from an inversion of long-period body waveforms. The earthquakes occurred on the Gibbs, Oceanographer, Hayes, Kane, 15 deg 20 min, and Vema transforms. The depth extent of faulting during each earthquake was estimated from the centroid depth and the fault width. The source mechanisms for all events in this study display the strike slip motion expected for transform fault earthquakes; slip vector azimuths agree to 2 to 3 deg of the local strike of the zone of active faulting. The only anomalies in mechanism were for two earthquakes near the western end of the Vema transform which occurred on significantly nonvertical fault planes. Secondary faulting, occurring either precursory to or near the end of the main episode of strike-slip rupture, was observed for 5 of the 12 earthquakes. For three events the secondary faulting was characterized by reverse motion on fault planes striking oblique to the trend of the transform. In all three cases, the site of secondary reverse faulting is near a compression jog in the current trace of the active transform fault zone. No evidence was found to support the conclusions of Engeln, Wiens, and Stein that oceanic transform faults in general are either hotter than expected from current thermal models or weaker than normal oceanic lithosphere.

Bergman, Eric A.; Solomon, Sean C.

1987-01-01

415

Transform fault earthquakes in the North Atlantic - Source mechanisms and depth of faulting  

NASA Technical Reports Server (NTRS)

The centroid depths and source mechanisms of 12 large earthquakes on transform faults of the northern Mid-Atlantic Ridge were determined from an inversion of long-period body waveforms. The earthquakes occurred on the Gibbs, Oceanographer, Hayes, Kane, 15 deg 20 min, and Vema transforms. The depth extent of faulting during each earthquake was estimated from the centroid depth and the fault width. The source mechanisms for all events in this study display the strike slip motion expected for transform fault earthquakes; slip vector azimuths agree to 2 to 3 deg of the local strike of the zone of active faulting. The only anomalies in mechanism were for two earthquakes near the western end of the Vema transform which occurred on significantly nonvertical fault planes. Secondary faulting, occurring either precursory to or near the end of the main episode of strike-slip rupture, was observed for 5 of the 12 earthquakes. For three events the secondary faulting was characterized by reverse motion on fault planes striking oblique to the trend of the transform. In all three cases, the site of secondary reverse faulting is near a compression jog in the current trace of the active transform fault zone. No evidence was found to support the conclusions of Engeln, Wiens, and Stein that oceanic transform faults in general are either hotter than expected from current thermal models or weaker than normal oceanic lithosphere.

Bergman, Eric A.; Solomon, Sean C.

1988-01-01

416

Paleomagnetic constraints on fault motion in the Hilina Fault System, south flank of Kilauea Volcano, Hawaii  

Microsoft Academic Search

Movement of the south flank of Kilauea Volcano in Hawaii has been associated with catastrophic landslide events. The surface expression of this former movement is the Hilina Fault System with fault scarps as high as 500 m. Paleomagnetic directions for lava flows exposed in the Hilina Fault scarps at Puu Kapukapu and Keana Bihopa on the Hilina Pali are used

Colleen M Riley; Jimmy F Diehl; Joseph L Kirschvink; Robert L Ripperdan

1999-01-01

417

Permeability of fault-related rocks, and implications for hydraulic structure of fault zones  

Microsoft Academic Search

The permeability structure of a fault zone in granitic rocks has been investigated by laboratory testing of intact core samples from the unfaulted protolith and the two principal fault zone components; the fault core and the damaged zone. The results of two test series performed on rocks obtained from outcrop are reported. First, tests performed at low confining pressure on

J. Goddard; C. Forster

1997-01-01

418

The morphology of strike-slip faults - Examples from the San Andreas Fault, California  

Microsoft Academic Search

The dilatational strains associated with vertical faults embedded in a horizontal plate are examined in the framework of fault kinematics and simple displacement boundary conditions. Using boundary element methods, a sequence of examples of dilatational strain fields associated with commonly occurring strike-slip fault zone features (bends, offsets, finite rupture lengths, and nonuniform slip distributions) is derived. The combinations of these

Roger Bilham; Geoffrey King

1989-01-01

419

Self-Organizing Map-Based Fault Dictionary Application Research on Rolling Bearing Faults  

Microsoft Academic Search

Vibration signal resulting from rolling bearing defects presents a rich content of physical information, the appropriate analysis methods of which can lead to the clear identification of the nature of the fault. A novel procedure is presented for construction of fault diagnosis dictionary through self-organization map (SOM). The experiments show that the bearing faults diagnosis dictionary could be effectively applied

Jun Pi; Jiaquan Lin; Xiangjiang Li

2008-01-01

420

Research paper Dating deep? Luminescence studies of fault gouge from the San Andreas Fault  

E-print Network

Research paper Dating deep? Luminescence studies of fault gouge from the San Andreas Fault zone 2 in revised form 26 April 2012 Accepted 27 April 2012 Available online xxx Keywords: SAFOD Fault gouge to deep samples is the high ambient temperature conditions, which act as a barrier to charge storage

421

DYNAMIC SLIP TRANSFER FROM THE DENALI TO TOTSCHUNDA FAULTS, ALASKA: TESTING THEORY FOR FAULT BRANCHING  

E-print Network

, Denali, Alaska, earthquake. This study adopts the theory and methodology of Poliakov et al. [2002 that along the Totschunda fault and with smaller slip. INTRODUCTION A Mw7.9 earthquake struck central Alaska1 DYNAMIC SLIP TRANSFER FROM THE DENALI TO TOTSCHUNDA FAULTS, ALASKA: TESTING THEORY FOR FAULT

Kame, Nobuki

422

Interaction of a Dynamic Rupture on a Fault Plane with Short Frictionless Fault Branches  

E-print Network

, University of Southern California, Los Angeles, CA, 90089, U.S.A. 2 Graduate Aeronautical Laboratories. Key words: Fault mechanics, earthquakes, branching, shear rupture, fault rock, damage. Introduction A major challenge in earthquake mechanics is the development of a quantitative relation between fault

Rosakis, Ares J.

423

Research paper Dating deep? Luminescence studies of fault gouge from the San Andreas Fault  

E-print Network

Research paper Dating deep? Luminescence studies of fault gouge from the San Andreas Fault zone 2 Resetting IRSL TL Dating a b s t r a c t This study aims to assess whether luminescence emission from fault in lower energy trapping sites. In this work luminescence experiments are being conducted on minerals from

424

Supervision, fault-detection and fault-diagnosis methods — An introduction  

Microsoft Academic Search

The operation of technical processes requires increasingly advanced supervision and fault diagnosis to improve reliability, safety and economy. This paper gives an introduction to the field of fault detection and diagnosis. It begins with a consideration of a knowledge-based procedure that is based on analytical and heuristic information. Then different methods of fault detection are considered, which extract features from

R. Isermann

1997-01-01

425

Fault location of two-terminal transmission lines with a small fault resistance  

Microsoft Academic Search

A numerical differentiation based algorithm for locating the faults occurring at the two-terminal transmission lines is presented in this paper. The fault line with two electric power systems at its two sides is modeled as two equivalent RL circuit transient processes. Im a transient process of RL circuit, the fault currents, which are much greater than the normal ones, include

J. K. Wu

2005-01-01

426

Collateral damage: Evolution with displacement of fracture distribution and secondary fault strands in fault  

E-print Network

Collateral damage: Evolution with displacement of fracture distribution and secondary fault strands in fault damage zones Heather M. Savage1,2 and Emily E. Brodsky1 Received 22 April 2010; revised 10 faults is governed by the same process. Based on our own field work combined with data from

Savage, Heather M.

427

New mapping and structural constraints on the Queen Charlotte-Fairweather Fault system, southeast Alaska  

NASA Astrophysics Data System (ADS)

The dextral Queen Charlotte-Fairweather Fault lies along the western margin of Canada and southeastern Alaska, a transform plate boundary accommodating motion between the North American and Pacific Plates. The Fairweather Fault is the northern extension of the Queen Charlotte Fault and has numerous and complex splays, including the Chichagof-Baranof Fault, the Peril Strait Fault, the Chatham Strait Fault, and the Icy Point-Lituya Bay Fault. Except for a few small areas, these fault systems have not been mapped in detail. We present updated geometries and fault maps of the entirety of the strike-slip system using seismic reflection and bathymetric data, including a 2004 seismic reflection survey (EW0408), 2005 United Nations Commission on Law of the Sea multibeam bathymetry, and legacy data from the U.S. Geological Survey (USGS) and the National Geophysical Data Center. This work is highly relevant for earthquake hazard research and mitigation in southeast Alaska. Several large (> Mw 7.0) earthquakes have occurred along this margin in the last century, impacting communities of southeastern Alaska and western Canada. Two large, recent events include 1) a Mw 7.7 earthquake that took place on 28 October 2012 near the Haida Gwaii Islands offshore of western Canada, and 2) a Mw 7.5 event which occurred on 05 January 2013, 330 km to the northwest and offshore of Craig, Alaska. Interestingly, the Haida Gwaii earthquake ruptured as a thrust event and the Craig earthquake ruptured with a near-vertical dextral strike-slip mechanism. Since a change in Pacific Plate motion around 4 million years ago, the southern Queen Charlotte Fault system has been obliquely converging at a rate of 20 mm/year, with the boundary accommodating about 80 km of perpendicular motion over that time. This convergence explains the Haida Gwaii thrust earthquake, but leaves questions about the along-strike fault structure. Two opposing end-member theories suggest convergence is accommodated by either: 1) Pacific Plate underthrusting beneath North America; or 2) crustal shortening via smaller, localized thrust faults. The underthrusting model assumes oblique slip along fault planes that transition to a lesser dip with increasing depth, whereas the local-thrust model requires strain partitioning via a series of thrust faults proximal to and inland from the main strike-slip trace. We provide insight into this system with improved surficial fault geometries that illuminate Queen Charlotte Fault structure in the context of the two recent earthquakes. We present these data in conjunction with preliminary aftershock locations and focal mechanisms for the 05 January 2013 Craig earthquake (obtained from a joint University of Texas-USGS OBS rapid-response survey), which offer new information about the seemingly changing along-strike dip and planar structure of the southern Queen Charlotte Fault. Additionally, we can now better constrain the Queen Charlotte's northern structure in relation with the Chatham Strait and Fairweather transforms.

Levoir, M. A.; Roland, E. C.; Gulick, S. P.; Haeussler, P. J.; Christeson, G. L.; Van Avendonk, H. J.

2013-12-01

428

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

429

Exact Functional Fault Collapsing in Combinational Logic Circuits Fault equivalence is an essential concept in digital VLSI de-  

E-print Network

transformations using stuck-at faults. It has been shown [18], logic addition/deletion is possible if the underlying faults that model these transformations are equiv- alent. Therefore, knowledge of faultExact Functional Fault Collapsing in Combinational Logic Circuits Abstract Fault equivalence

Veneris, Andreas

430

The San Andreas Fault System Paul Withers Wallace RE, The San Andreas Fault System, California, USGS Professional Paper 1515,  

E-print Network

The San Andreas Fault System ­ Paul Withers Wallace RE, The San Andreas Fault System, California://www.johnmartin.com/earthquakes/eqsafs/INDEX.HTM) Schultz SS and Wallace RE, The San Andreas Fault, USGS General Interest Publication, 1989 (http San Andreas fault system, a complex of faults that display predominantly large- scale strike slip

Withers, Paul

431

Initiation of the San Jacinto Fault and its Interaction with the San Andreas Fault: Insights from Geodynamic Modeling  

E-print Network

Initiation of the San Jacinto Fault and its Interaction with the San Andreas Fault: Insights from Geodynamic Modeling QINGSONG LI 1,2 and MIAN LIU 1 Abstract--The San Andreas Fault (SAF) is the Pacific plate motion. Key words: Strain localization, fault interaction, San Andreas Fault, restraining bend

Liu, Mian

432

Toward Reducing Fault Fix Time: Understanding Developer Behavior for the Design of Automated Fault Detection Tools, the Full Report  

E-print Network

Toward Reducing Fault Fix Time: Understanding Developer Behavior for the Design of Automated Fault}@csc.ncsu.edu Abstract The longer a fault remains in the code from the time it was injected, the more time it will take to fix the fault. Increasingly, automated fault detection (AFD) tools are providing developers

Young, R. Michael

433

Fault collapsing is the process of reducing the number of faults by using redundance and equivalence/dominance  

E-print Network

1 Abstract Fault collapsing is the process of reducing the number of faults by using redundance and equivalence/dominance relationships among faults. Exact fault collapsing can be easily applied locally such as execution time and/or memory. In this paper, we present EGFC, an exact global fault collapsing tool

Al-Asaad, Hussain

434

Geophysical and Geological Evidence of Neotectonic Deformation Along the Hovey Lake Fault, Lower Wabash Valley Fault System, Central United States  

Microsoft Academic Search

High-resolution seismic (shear-wave) reflection profiles were collected over a segment of the Hovey Lake fault, a known Paleozoic fault within a system of faults in the southernmost Wabash River valley of the central United States. Although the system of faults, called the Wabash Valley fault system, lie in an area of recognized prehistoric and contemporary seismicity, their seismogenic potential remain

E. W. Woolery; F. A. Rutledge; Z. Wang

2004-01-01

435

Fault-tolerant parallel processor  

SciTech Connect

This paper addresses issues central to the design and operation of an ultrarel