Modeling fault rupture hazard for the proposed repository at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Coppersmith, K.J.; Youngs, R.R.

1992-01-01

In this paper as part of the Electric Power Research Institute's High Level Waste program, the authors have developed a preliminary probabilistic model for assessing the hazard of fault rupture to the proposed high level waste repository at Yucca Mountain. The model is composed of two parts: the earthquake occurrence model that describes the three-dimensional geometry of earthquake sources and the earthquake recurrence characteristics for all sources in the site vicinity; and the rupture model that describes the probability of coseismic fault rupture of various lengths and amounts of displacement within the repository horizon 350 m below the surface. The latter uses empirical data from normal-faulting earthquakes to relate the rupture dimensions and fault displacement amounts to the magnitude of the earthquake. using a simulation procedure, we allow for earthquake occurrence on all of the earthquake sources in the site vicinity, model the location and displacement due to primary faults, and model the occurrence of secondary faulting in conjunction with primary faulting

Strontium isotopic and trace element geochemistry of the saddle mountains and Grande Ronde Basalts of the Columbia River Basalt Group

International Nuclear Information System (INIS)

Nelson, D.O.

1980-01-01

The Columbia River Basalt (CRB) group displays significant variations in major and trace element and Sr isotopic compositions. These compositions reflect complex and variable origins for the CRB magmas. Among the most varied is the Saddle Mountains Basalt (SMB) in which Sr ratios vary from 0.7078 to 0.7147 +- 0.002. The higher ratios reflect contamination through consistent correlations with major element compositions. Modeling suggests contamination by assimilation of 4.4 to 9.4 wt % of radiogenic crustal rocks. High delta 18 O values (up to +7.68 per mil) support the model. Age and field relations suggest that the contamination flowrocks are not the result of progressive contamination of a single magma, but rather reflect the contamination of independent magmas during this ascent

Geology and geologic history of the Moscow-Pullman basin, Idaho and Washington, from late Grande Ronde to late Saddle Mountains time

Science.gov (United States)

Bush, John H; Garwood, Dean L; Dunlap, Pamela

2016-01-01

The Moscow-Pullman basin, located on the eastern margin of the Columbia River flood basalt province, consists of a subsurface mosaic of interlayered Miocene sediments and lava flows of the Imnaha, Grande Ronde, Wanapum, and Saddle Mountains Basalts of the Columbia River Basalt Group. This sequence is ~1800 ft (550 m) thick in the east around Moscow, Idaho, and exceeds 2300 ft (700 m) in the west at Pullman, Washington. Most flows entered from the west into a topographic low, partially surrounded by steep mountainous terrain. These flows caused a rapid rise in base level and deposition of immature sediments. This field guide focuses on the upper Grande Ronde Basalt, Wanapum Basalt, and sediments of the Latah Formation.Late Grande Ronde flows terminated midway into the basin to begin the formation of a topographic high that now separates a thick sediment wedge of the Vantage Member to the east of the high from a thin layer to the west. Disrupted by lava flows, streams were pushed from a west-flowing direction to a north-northwest orientation and drained the basin through a gap between steptoes toward Palouse, Washington. Emplacement of the Roza flow of the Wanapum Basalt against the western side of the topographic high was instrumental in this process, plugging west-flowing drainages and increasing deposition of Vantage sediments east of the high. The overlying basalt of Lolo covered both the Roza flow and Vantage sediments, blocking all drainages, and was in turn covered by sediments interlayered with local Saddle Mountains Basalt flows. Reestablishment of west-flowing drainages has been slow.The uppermost Grande Ronde, the Vantage, and the Wanapum contain what is known as the upper aquifer. The water supply is controlled, in part, by thickness, composition, and distribution of the Vantage sediments. A buried channel of the Vantage likely connects the upper aquifer to Palouse, Washington, outside the basin. This field guide locates outcrops; relates them to

The Sundance fault: A newly recognized shear zone at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Spengler, R.W.; Braun, C.A.; Martin, L.G.; Weisenberg, C.W.

1994-01-01

Ongoing detailed mapping at a scale of 1:240 of structural features within the potential repository area indicates the presence of several previously unrecognized structural features. Minor north-trending west-side-down faults occur east and west of the Ghost Dance fault and suggest a total width of the Ghost Dance fault system of nearly 366 m (1200 ft). A zone of near-vertical N30 degrees - 40 degrees W - trending faults, at least 274 m (900 ft) wide, has been identified in the northern part of our study area and may traverse across the proposed repository area. On the basis of a preliminary analysis of available data, we propose to name this zone the ''Sundance fault system'' and the dominant structure, occurring near the middle of the zone, the ''Sundance fault.'' Some field relations suggest left-stepping deflections of north-trending faults along a preexisting northwest-trending structural fabric. Other field observations suggest that the ''Sundance fault system'' offsets the Ghost Dance fault system in an apparent right lateral sense by at least 52 m (170 ft). Additional detailed field studies, however, are needed to better understand structural complexities at Yucca Mountain

Fluid-faulting interactions: Fracture-mesh and fault-valve behavior in the February 2014 Mammoth Mountain, California, earthquake swarm

Science.gov (United States)

Shelly, David R.; Taira, Taka’aki; Prejean, Stephanie; Hill, David P.; Dreger, Douglas S.

2015-01-01

Faulting and fluid transport in the subsurface are highly coupled processes, which may manifest seismically as earthquake swarms. A swarm in February 2014 beneath densely monitored Mammoth Mountain, California, provides an opportunity to witness these interactions in high resolution. Toward this goal, we employ massive waveform-correlation-based event detection and relative relocation, which quadruples the swarm catalog to more than 6000 earthquakes and produces high-precision locations even for very small events. The swarm's main seismic zone forms a distributed fracture mesh, with individual faults activated in short earthquake bursts. The largest event of the sequence, M 3.1, apparently acted as a fault valve and was followed by a distinct wave of earthquakes propagating ~1 km westward from the updip edge of rupture, 1–2 h later. Late in the swarm, multiple small, shallower subsidiary faults activated with pronounced hypocenter migration, suggesting that a broader fluid pressure pulse propagated through the subsurface.

A preliminary comparison of mineral deposits in faults near Yucca Mountain, Nevada, with possible analogs

International Nuclear Information System (INIS)

Vaniman, D.T.; Bish, D.L.; Chipera, S.

1988-05-01

Several faults near Yucca Mountain, Nevada, contain abundant calcite and opal-CT, with lesser amounts of opal-A and sepiolite or smectite. These secondary minerals are being studied to determine the directions, amounts, and timing of transport involved in their formation. Such information is important for evaluating the future performances of a potential high-level nuclear waste repository beneath Yucca Mountain. This report is a preliminary assessment of how those minerals were formed. Possible analog deposits from known hydrothermal veins, warm springs, cold springs or seeps, soils, and aeolian sands were studied by petrographic and x-ray diffraction methods for comparison with the minerals deposited in the faults; there are major mineralogic differences in all of these environments except in the aeolian sands and in some cold seeps. Preliminary conclusions are that the deposits in the faults and in the sand ramps are closely related, and that the process of deposition did not require upward transport from depth. 35 refs., 25 figs

The Hanford Site's Gable Mountain structure: A comparison of the recurrence of design earthquakes based on fault slip rates and a probabilistic exposure model

International Nuclear Information System (INIS)

Rohay, A.C.

1991-01-01

Gable Mountain is a segment of the Umtanum Ridge-Gable Mountain structural trend, an east-west trending series of anticlines, one of the major geologic structures on the Hanford Site. A probabilistic seismic exposure model indicates that Gable Mountain and two adjacent segments contribute significantly to the seismic hazard at the Hanford Site. Geologic measurements of the uplift of initially horizontal (11-12 Ma) basalt flows indicate that a broad, continuous, primary anticline grew at an average rate of 0.009-0.011 mm/a, and narrow, segmented, secondary anticlines grew at rates of 0.009 mm/a at Gable Butte and 0.018 mm/a at Gable Mountain. The buried Southeast Anticline appears to have a different geometry, consisting of a single, intermediate-width anticline with an estimated growth rate of 0.007 mm/a. The recurrence rate and maximum magnitude of earthquakes for the fault models were used to estimate the fault slip rate for each of the fault models and to determine the implied structural growth rate of the segments. The current model for Gable Mountain-Gable Butte predicts 0.004 mm/a of vertical uplift due to primary faulting and 0.008 mm/a due to secondary faulting. These rates are roughly half the structurally estimated rates for Gable Mountain, but the model does not account for the smaller secondary fold at Gable Butte. The model predicted an uplift rate for the Southeast Anticline of 0.006 mm/a, caused by the low open-quotes fault capabilityclose quotes weighting rather than a different fault geometry. The effects of previous modifications to the fault models are examined and potential future modifications are suggested. For example, the earthquake recurrence relationship used in the current exposure model has a b-value of 1.15, compared to a previous value of 0.85. This increases the implied deformation rates due to secondary fault models, and therefore supports the use of this regionally determined b-value to this fault/fold system

Preliminary U-series disequilibrium and thermoluminescence ages of surficial deposits and paleosols associated with Quaternary fault, Eastern Yucca Mountain

International Nuclear Information System (INIS)

Paces, J.B.; Menges, C.M.; Bush, C.A.; Futa, K.; Millard, H.T.; Maat, P.B.; Whitney, J.W.; Widmann, B.; Wesling, J.R.

1994-01-01

Geochronological control is an essential component of paleoseismic evaluation of faults in the Yucca Mountain region. New U-series disequilibrium and thermoluminescence age estimates for pedogenic deposits that bracket surface-rupture events are presented from four sites exposing the Paintbrush Canyon, Bow Ridge and Stagecoach Road faults. Ages show an internal consistency with stratigraphic relationships as well as an overall concordancy between the two independent geochronometers. Age estimates are therefore interpreted to date depositional events or episodes of pedogenic carbonate mobility that can be used to establish a paleoseismic fault chronology. Ultimately, this type of chronological information will be used to evaluate seismic hazards at Yucca Mountain

Preliminary results of paleoseismic investigations of Quaternary faults on eastern Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

Menges, C.M.; Oswald, J.A.; Coe, J.A.

1995-01-01

Site characterization of the potential nuclear waste repository at Yucca Mountain, Nevada, requires detailed knowledge of the displacement histories of nearby Quaternary faults. Ongoing paleoseismic studies provide data on the amount and rates of Quaternary activity on the Paintbrush Canyon, Bow Ridge, and Stagecoach Road faults along the eastern margin of the mountain over varying time spans of 0-700 ka to perhaps 0-30 ka, depending on the site. Preliminary stratigraphic interpretations of deposits and deformation at many logged trenches and natural exposures indicate that each of these faults have experienced from 3 to 8 surface-rupturing earthquakes associated with variable dip-slip displacements per event ranging from 5 to 115 cm, and commonly in the range of 20 to 85 cm. Cumulative dip-slip offsets of units with broadly assigned ages of 100-200 ka are typically less than 200 cm, although accounting for the effects of possible left normal-oblique slip could increase these displacements by factors of 1.1 to 1.7. Current age constraints indicate recurrence intervals of 10 4 to 10 5 years (commonly between 30 and 80 k.y.) and slip rates of 0.001 to 0.08 mm/yr (typically 0.01-0.02 mm/yr). Based on available timing data, the ages of the most recent ruptures varies among the faults; they appear younger on the Stagecoach Road Fault (∼5-20 ka) relative to the southern Paintbrush Canyon and Bow Ridge faults (∼30-100 ka)

The Trans-Rocky Mountain Fault System - A Fundamental Precambrian Strike-Slip System

Science.gov (United States)

Sims, P.K.

2009-01-01

Recognition of a major Precambrian continental-scale, two-stage conjugate strike-slip fault system - here designated as the Trans-Rocky Mountain fault system - provides new insights into the architecture of the North American continent. The fault system consists chiefly of steep linear to curvilinear, en echelon, braided and branching ductile-brittle shears and faults, and local coeval en echelon folds of northwest strike, that cut indiscriminately across both Proterozoic and Archean cratonic elements. The fault system formed during late stages of two distinct tectonic episodes: Neoarchean and Paleoproterozoic orogenies at about 2.70 and 1.70 billion years (Ga). In the Archean Superior province, the fault system formed (about 2.70-2.65 Ga) during a late stage of the main deformation that involved oblique shortening (dextral transpression) across the region and progressed from crystal-plastic to ductile-brittle deformation. In Paleoproterozoic terranes, the fault system formed about 1.70 Ga, shortly following amalgamation of Paleoproterozoic and Archean terranes and the main Paleoproterozoic plastic-fabric-producing events in the protocontinent, chiefly during sinistral transpression. The postulated driving force for the fault system is subcontinental mantle deformation, the bottom-driven deformation of previous investigators. This model, based on seismic anisotropy, invokes mechanical coupling and subsequent shear between the lithosphere and the asthenosphere such that a major driving force for plate motion is deep-mantle flow.

Bouguer gravity and crustal structure of the Dead Sea transform fault and adjacent mountain belts in Lebanon

Science.gov (United States)

Kamal; Khawlie, Mohamad; Haddad, Fuad; Barazangi, Muawia; Seber, Dogan; Chaimov, Thomas

1993-08-01

The northern extension of the Dead Sea transform fault in southern Lebanon bifurcates into several faults that cross Lebanon from south to north. The main strand, the Yammouneh fault, marks the boundary between the Levantine (eastern Mediterranean) and Arabian plates and separates the western mountain range (Mount Lebanon) from the eastern mountain range (Anti-Lebanon). Bouguer gravity contours in Lebanon approximately follow topographic contours; i.e., positive Bouguer anomalies are associated with the Mount Lebanon and Anti-Lebanon ranges. This suggests that the region is not in simple isostatic compensation. Gravity observations based on 2.5-dimensional modeling and other available geological and geophysical information have produced the following interpretations. (1) The crust of Lebanon thins from ˜35 km beneath the Anti-Lebanon range, near the Syrian border, to ˜27 km beneath the Lebanese coast. No crustal roots exist beneath the Lebanese ranges. (2) The depth to basement is ˜3.5-6 km below sea level under the ranges and is ˜8-10 km beneath the Bekaa depression. (3) The Yammouneh fault bifurcates northward into two branches; one passes beneath the Yammouneh Lake through the eastern part of Mount Lebanon and another bisects the northern part of the Bekaa Valley (i.e., Mid-Bekaa fault). The Lebanese mountain ranges and the Bekaa depression were formed as a result of transtension and later transpression associated with the relative motion of a few crustal blocks in response to the northward movement of the Arabian plate relative to the Levantine plate.

Influence of faults on groundwater flow and transport at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Cohen, Andrew J.B.; Sitar, Nicholas

1999-01-01

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

Criteria for design of the Yucca Mountain structures, systems and components for fault displacement

International Nuclear Information System (INIS)

Stepp, C.; Hossain, Q.; Nesbit, S.; Pezzopane, S.; Hardy, M.

1995-01-01

The DOE intends to design the Yucca Mountain high-level waste facility structures, systems and components (SSCs) for fault displacements to provide reasonable assurance that they will meet the preclosure safety performance objectives established by 10 CFR Part 60. To the extent achievable, fault displacement design of the facility will follow guidance provided in the NRC Staff Technical Position. Fault avoidance will be the primary design criterion, especially for spatially compact or clustered SSCs. When fault avoidance is not reasonably achievable, expected to be the case for most spatially extended SSCs, engineering design procedures and criteria or repair and rehabilitation actions, depending on the SSC's importance to safety, are provided. SSCs that have radiological safety importance will be designed for fault displacements that correspond to the hazard exceedance frequency equal to their established seismic safety performance goals. Fault displacement loads are generally localized and may cause local inelastic response of SSCs. For this reason, the DOE intends to use strain-based design acceptance criteria similar to the strain-based criteria used to design nuclear plant SSCs for impact and impulsive loads

Non-tectonic exposure Rates along Bedrock Fault Scarps in an active Mountain Belt of the central Apennines

Science.gov (United States)

Kastelic, Vanja; Burrato, Pierfrancesco; Carafa, Michele M. C.; Basili, Roberto

2017-04-01

The central Apennines (Italy) are a mountain chain affected by post-collisional active extension along NW-SE striking normal faults and well-documented regional-scale uplift. Moderate to strong earthquakes along the seismogenically active extensional faults are frequent in this area, thus a good knowledge on the characteristics of the hosting faults is necessary for realistic seismic hazard models. The studied bedrock fault surfaces are generally located at various heights on mountain fronts above the local base level of glacio-fluvial valleys and intermountain fluvio-lacustrine basins and are laterally confined to the extent of related mountain fronts. In order to investigate the exposure of the bedrock fault scarps from under their slope-deposit cover, a process that has often been exclusively attributed to co-seismic earthquake slip and used as proxy for tectonic slip rates and earthquake recurrence estimations, we have set up a measurement experiment along various such structures. In this experiment we measure the relative position of chosen markers on the bedrock surface and the material found directly at the contact with its hanging wall. We present the results of monitoring the contact between the exposed fault surfaces and slope deposits at 23 measurement points on 12 different faults over 3.4 year-long observation period. We detected either downward or upward movements of the slope deposit with respect to the fault surface between consecutive measurements. During the entire observation period all points, except one, registered a net downward movement in the 2.9 - 25.6 mm/yr range, resulting in the progressive exposure of the fault surface. During the monitoring period no major earthquakes occurred in the region, demonstrating the measured exposure process is disconnected from seismic activity. We do however observe a positive correlation between the higher exposure in respect to higher average temperatures. Our results indicate that the fault surface

27 CFR 9.203 - Saddle Rock-Malibu.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Saddle Rock-Malibu. 9.203... Saddle Rock-Malibu. (a) Name. The name of the viticultural area described in this section is “Saddle Rock-Malibu”. For purposes of part 4 of this chapter, “Saddle Rock-Malibu” is a term of viticultural...

Power inverter design for ASDEX Upgrade saddle coils

Energy Technology Data Exchange (ETDEWEB)

Teschke, M., E-mail: teschke@ipp.mpg.de [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany); Suttrop, W.; Rott, M. [Max Planck Institute for Plasma Physics, EURATOM Association, Boltzmannstr. 2, 85748 Garching (Germany)

2013-10-15

Highlights: ► A cost effective inverter topology for AUG's 16 in-vessel saddle coils has been found. ► Use of commercially available power modules is possible. ► Exchange of reactive power between multiple inverters is possible. ► Influence of electromagnetic noise to AUG's diagnostics was measured. ► Gas insulation of electric feed through significantly depends on magnetic fields. It is protected by fast turn-off circuit. -- Abstract: A set of 16 in-vessel saddle coils has been installed in the ASDEX Upgrade (AUG) experiment since the end of 2011 [1]. To achieve full performance, it is necessary to operate them with alternating current (AC) of arbitrary waveforms. To generate spatially resolved magnetic fields, it is required to allocate separate power inverters to every single coil. Therefore, different topologies are analyzed and compared. Studies of the commutation behavior of power stages, different pulse width modulation (PWM) schemes and single-phase-to-earth fault detection are executed. Experiments to evaluate the electromagnetic interference (EMI) of possible inverter topologies on the AUG diagnostics are done as well. A special focus is put on the feasibility of analyzed topologies using industrially available and fully assembled “power modules” to minimize development effort and costs.

Approximating chaotic saddles for delay differential equations.

Science.gov (United States)

Taylor, S Richard; Campbell, Sue Ann

2007-04-01

Chaotic saddles are unstable invariant sets in the phase space of dynamical systems that exhibit transient chaos. They play a key role in mediating transport processes involving scattering and chaotic transients. Here we present evidence (long chaotic transients and fractal basins of attraction) of transient chaos in a "logistic" delay differential equation. We adapt an existing method (stagger-and-step) to numerically construct the chaotic saddle for this system. This is the first such analysis of transient chaos in an infinite-dimensional dynamical system, and in delay differential equations in particular. Using Poincaré section techniques we illustrate approaches to visualizing the saddle set, and confirm that the saddle has the Cantor-like fractal structure consistent with a chaotic saddle generated by horseshoe-type dynamics.

Approximating chaotic saddles for delay differential equations

Science.gov (United States)

Taylor, S. Richard; Campbell, Sue Ann

2007-04-01

Chaotic saddles are unstable invariant sets in the phase space of dynamical systems that exhibit transient chaos. They play a key role in mediating transport processes involving scattering and chaotic transients. Here we present evidence (long chaotic transients and fractal basins of attraction) of transient chaos in a “logistic” delay differential equation. We adapt an existing method (stagger-and-step) to numerically construct the chaotic saddle for this system. This is the first such analysis of transient chaos in an infinite-dimensional dynamical system, and in delay differential equations in particular. Using Poincaré section techniques we illustrate approaches to visualizing the saddle set, and confirm that the saddle has the Cantor-like fractal structure consistent with a chaotic saddle generated by horseshoe-type dynamics.

The timing of fault motion in Death Valley from Illite Age Analysis of fault gouge

Science.gov (United States)

Lynch, E. A.; Haines, S. H.; Van der Pluijm, B.

2014-12-01

We constrained the timing of fluid circulation and associated fault motion in the Death Valley region of the US Basin and Range Province from Illite Age Analysis (IAA) of fault gouge at seven Low-Angle Normal Fault (LANF) exposures in the Black Mountains and Panamint Mountains, and in two nearby areas. 40Ar/39Ar ages of neoformed, illitic clay minerals in these fault zones range from 2.8 Ma to 18.6 Ma, preserving asynchronous fault motion across the region that corresponds to an evolving history of crustal block movements during Neogene extensional deformation. From north to south, along the western side of the Panamint Range, the Mosaic Canyon fault yields an authigenic illite age of 16.9±2.9 Ma, the Emigrant fault has ages of less than 10-12 Ma at Tucki Mountain and Wildrose Canyon, and an age of 3.6±0.17 Ma was obtained for the Panamint Front Range LANF at South Park Canyon. Across Death Valley, along the western side of the Black Mountains, Ar ages of clay minerals are 3.2±3.9 Ma, 12.2±0.13 Ma and 2.8±0.45 Ma for the Amargosa Detachment, the Gregory Peak Fault and the Mormon Point Turtleback detachment, respectively. Complementary analysis of the δH composition of neoformed clays shows a primarily meteoric source for the mineralizing fluids in these LANF zones. The ages fall into two geologic timespans, reflecting activity pulses in the Middle Miocene and in the Upper Pliocene. Activity on both of the range front LANFs does not appear to be localized on any single portion of these fault systems. Middle Miocene fault rock ages of neoformed clays were also obtained in the Ruby Mountains (10.5±1.2 Ma) to the north of the Death Valley region and to the south in the Whipple Mountains (14.3±0.19 Ma). The presence of similar, bracketed times of activity indicate that LANFs in the Death Valley region were tectonically linked, while isotopic signatures indicate that faulting pulses involved surface fluid penetration.

36 CFR 34.10 - Saddle and pack animals.

Science.gov (United States)

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Saddle and pack animals. 34... INTERIOR EL PORTAL ADMINISTRATIVE SITE REGULATIONS § 34.10 Saddle and pack animals. The use of saddle and pack animals is prohibited without a permit from the Superintendent. ...

Feature-Based Retinal Image Registration Using D-Saddle Feature

Directory of Open Access Journals (Sweden)

Roziana Ramli

2017-01-01

Full Text Available Retinal image registration is important to assist diagnosis and monitor retinal diseases, such as diabetic retinopathy and glaucoma. However, registering retinal images for various registration applications requires the detection and distribution of feature points on the low-quality region that consists of vessels of varying contrast and sizes. A recent feature detector known as Saddle detects feature points on vessels that are poorly distributed and densely positioned on strong contrast vessels. Therefore, we propose a multiresolution difference of Gaussian pyramid with Saddle detector (D-Saddle to detect feature points on the low-quality region that consists of vessels with varying contrast and sizes. D-Saddle is tested on Fundus Image Registration (FIRE Dataset that consists of 134 retinal image pairs. Experimental results show that D-Saddle successfully registered 43% of retinal image pairs with average registration accuracy of 2.329 pixels while a lower success rate is observed in other four state-of-the-art retinal image registration methods GDB-ICP (28%, Harris-PIIFD (4%, H-M (16%, and Saddle (16%. Furthermore, the registration accuracy of D-Saddle has the weakest correlation (Spearman with the intensity uniformity metric among all methods. Finally, the paired t-test shows that D-Saddle significantly improved the overall registration accuracy of the original Saddle.

The Devils Mountain Fault zone: An active Cascadia upper plate zone of deformation, Pacific Northwest of North America

Science.gov (United States)

Barrie, J. Vaughn; Greene, H. Gary

2018-02-01

The Devils Mountain Fault Zone (DMFZ) extends east to west from Washington State to just south of Victoria, British Columbia, in the northern Strait of Juan de Fuca of Canada and the USA. Recently collected geophysical data were used to map this fault zone in detail, which show the main fault trace, and associated primary and secondary (conjugate) strands, and extensive northeast-southwest oriented folding that occurs within a 6 km wide deformation zone. The fault zone has been active in the Holocene as seen in the offset and disrupted upper Quaternary strata, seafloor displacement, and deformation within sediment cores taken close to the seafloor expression of the faults. Data suggest that the present DMFZ and the re-activated Leech River Fault may be part of the same fault system. Based on the length and previously estimated slip rates of the fault zone in Washington State, the DMFZ appears to have the potential of producing a strong earthquake, perhaps as large as magnitude 7.5 or greater, within 2 km of the city of Victoria.

'Saddle-point' ionization

International Nuclear Information System (INIS)

Gay, T.J.; Hale, E.B.; Irby, V.D.; Olson, R.E.; Missouri Univ., Rolla; Berry, H.G.

1988-01-01

We have studied the ionization of rare gases by protons at intermediate energies, i.e., energies at which the velocities of the proton and the target-gas valence electrons are comparable. A significant channel for electron production in the forward direction is shown to be 'saddle-point' ionization, in which electrons are stranded on or near the saddle-point of electric potential between the receding projectile and the ionized target. Such electrons yield characteristic energy spectra, and contribute significantly to forward-electron-production cross sections. Classical trajectory Monte Carlo calculations are found to provide qualitative agreement with our measurements and the earlier measurements of Rudd and coworkers, and reproduce, in detail, the features of the general ionization spectra. (orig.)

Late Pleistocene Activity and deformation features of the North Margin Fault of West Qinling Mountains, northeastern Tibet

Science.gov (United States)

Chen, P.; Lin, A.; Yan, B.

2017-12-01

Abstract: A precise constraints of slip rates of active faults within and around Tibetan Plateau will provide us a definite and explicit knowledge of continental dynamics and present-day tectonic evolution. The major strike-slip faults in the northern and northeastern Tibetan Plateau, including the Altyn Tagh fault and Kunlun fault play a vital role in dissipating and transferring the strain energy. The WNW-trending North Margin Fault of West Qinling Mountains (hereafter name NMFWQM, the target of this study) developed along the topographic boundary between Longzhong basin and the Qinling mountains. Intensive Historic records show that large earthquakes repeatedly in the area around the NMFWQM, including the AD 143 M 7.0 Gangu West earthquake; AD 734 M≥7.0 Tianshui earthquake; AD 1654 M 8.0 Tianshui South earthquake and the most recent 2013 Mw6.0 Zhangxian earthquake. In this study, we investigated the structural features and activity of the NMFWQM including the nature of the fault, slip rate, and paleoseismicity by interpretation of high-resolution remote sensing images and field investigation. Based on the interpretations of high resolution satellite images, field investigations and 14C dating ages, we conclude the following conclusions: 1) The drainage systems have been systematical deflected or offset sinistrally along the fault trace; 2) The amounts of displacement (D) show a positive linear correlation with the upstream length (L) from the deflected point of offset river channels as DaL (a: a certain coefficient); 3) The alluvial fans and terrace risers formed in the last interglacial period are systematically offset by 16.4m to 93.9 m, indicating an accumulation of horizontal displacements as that observed in the offset drainages; 4) A horizontal slip rate is estimated to be 2.5-3.1 mm/yr with an average of 2.8 mm/yr. Comparing with the well-know strike-slip active faults developed in the northern Tibetan Plateau, such as the Altyn Tagh fault and Kunlun

Complex economic dynamics: Chaotic saddle, crisis and intermittency

International Nuclear Information System (INIS)

Chian, Abraham C.-L.; Rempel, Erico L.; Rogers, Colin

2006-01-01

Complex economic dynamics is studied by a forced oscillator model of business cycles. The technique of numerical modeling is applied to characterize the fundamental properties of complex economic systems which exhibit multiscale and multistability behaviors, as well as coexistence of order and chaos. In particular, we focus on the dynamics and structure of unstable periodic orbits and chaotic saddles within a periodic window of the bifurcation diagram, at the onset of a saddle-node bifurcation and of an attractor merging crisis, and in the chaotic regions associated with type-I intermittency and crisis-induced intermittency, in non-linear economic cycles. Inside a periodic window, chaotic saddles are responsible for the transient motion preceding convergence to a periodic or a chaotic attractor. The links between chaotic saddles, crisis and intermittency in complex economic dynamics are discussed. We show that a chaotic attractor is composed of chaotic saddles and unstable periodic orbits located in the gap regions of chaotic saddles. Non-linear modeling of economic chaotic saddle, crisis and intermittency can improve our understanding of the dynamics of financial intermittency observed in stock market and foreign exchange market. Characterization of the complex dynamics of economic systems is a powerful tool for pattern recognition and forecasting of business and financial cycles, as well as for optimization of management strategy and decision technology

The Taylor saddle effacement: a new technique for correction of saddle nose deformity.

Science.gov (United States)

Taylor, S Mark; Rigby, Matthew H

2008-02-01

To describe a novel technique, the Taylor saddle effacement (TSE), for correction of saddle nose deformity using autologous grafts from the lower lateral cartilages. A prospective evaluation of six patients, all of whom had the TSE performed. Photographs were taken in combination with completion of a rhinoplasty outcomes questionnaire preoperatively and at 6 months. The questionnaire included a visual analogue scale (VAS) of nasal breathing and a rhinoplasty outcomes evaluation (ROE) of nasal function and esthetics. All six patients had improvement in both their global nasal airflow on the VAS and on their ROE that was statistically significant. The mean preoperative VAS score was 5.8 compared with our postoperative mean of 8.5 of a possible 10. Mean ROE scores improved from 34.7 to 85.5. At 6 months, all patients felt that their nasal appearance had improved. The TSE is a simple and reliable technique for correction of saddle nose deformity. This prospective study has demonstrated improvement in both nasal function and esthetics when it is employed.

Acceleration of saddle-point searches with machine learning

Energy Technology Data Exchange (ETDEWEB)

Peterson, Andrew A., E-mail: andrew-peterson@brown.edu [School of Engineering, Brown University, Providence, Rhode Island 02912 (United States)

2016-08-21

In atomistic simulations, the location of the saddle point on the potential-energy surface (PES) gives important information on transitions between local minima, for example, via transition-state theory. However, the search for saddle points often involves hundreds or thousands of ab initio force calls, which are typically all done at full accuracy. This results in the vast majority of the computational effort being spent calculating the electronic structure of states not important to the researcher, and very little time performing the calculation of the saddle point state itself. In this work, we describe how machine learning (ML) can reduce the number of intermediate ab initio calculations needed to locate saddle points. Since machine-learning models can learn from, and thus mimic, atomistic simulations, the saddle-point search can be conducted rapidly in the machine-learning representation. The saddle-point prediction can then be verified by an ab initio calculation; if it is incorrect, this strategically has identified regions of the PES where the machine-learning representation has insufficient training data. When these training data are used to improve the machine-learning model, the estimates greatly improve. This approach can be systematized, and in two simple example problems we demonstrate a dramatic reduction in the number of ab initio force calls. We expect that this approach and future refinements will greatly accelerate searches for saddle points, as well as other searches on the potential energy surface, as machine-learning methods see greater adoption by the atomistics community.

Acceleration of saddle-point searches with machine learning

International Nuclear Information System (INIS)

Peterson, Andrew A.

2016-01-01

In atomistic simulations, the location of the saddle point on the potential-energy surface (PES) gives important information on transitions between local minima, for example, via transition-state theory. However, the search for saddle points often involves hundreds or thousands of ab initio force calls, which are typically all done at full accuracy. This results in the vast majority of the computational effort being spent calculating the electronic structure of states not important to the researcher, and very little time performing the calculation of the saddle point state itself. In this work, we describe how machine learning (ML) can reduce the number of intermediate ab initio calculations needed to locate saddle points. Since machine-learning models can learn from, and thus mimic, atomistic simulations, the saddle-point search can be conducted rapidly in the machine-learning representation. The saddle-point prediction can then be verified by an ab initio calculation; if it is incorrect, this strategically has identified regions of the PES where the machine-learning representation has insufficient training data. When these training data are used to improve the machine-learning model, the estimates greatly improve. This approach can be systematized, and in two simple example problems we demonstrate a dramatic reduction in the number of ab initio force calls. We expect that this approach and future refinements will greatly accelerate searches for saddle points, as well as other searches on the potential energy surface, as machine-learning methods see greater adoption by the atomistics community.

Acceleration of saddle-point searches with machine learning.

Science.gov (United States)

Peterson, Andrew A

2016-08-21

In atomistic simulations, the location of the saddle point on the potential-energy surface (PES) gives important information on transitions between local minima, for example, via transition-state theory. However, the search for saddle points often involves hundreds or thousands of ab initio force calls, which are typically all done at full accuracy. This results in the vast majority of the computational effort being spent calculating the electronic structure of states not important to the researcher, and very little time performing the calculation of the saddle point state itself. In this work, we describe how machine learning (ML) can reduce the number of intermediate ab initio calculations needed to locate saddle points. Since machine-learning models can learn from, and thus mimic, atomistic simulations, the saddle-point search can be conducted rapidly in the machine-learning representation. The saddle-point prediction can then be verified by an ab initio calculation; if it is incorrect, this strategically has identified regions of the PES where the machine-learning representation has insufficient training data. When these training data are used to improve the machine-learning model, the estimates greatly improve. This approach can be systematized, and in two simple example problems we demonstrate a dramatic reduction in the number of ab initio force calls. We expect that this approach and future refinements will greatly accelerate searches for saddle points, as well as other searches on the potential energy surface, as machine-learning methods see greater adoption by the atomistics community.

Geologic map of the Paintbrush Canyon Area, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Dickerson, R.P.; Drake, R.M. II

1998-01-01

This geologic map is produced to support site characterization studies of Yucca Mountain, Nevada, site of a potential nuclear waste storage facility. The area encompassed by this map lies between Yucca Wash and Fortymile Canyon, northeast of Yucca Mountain. It is on the southern flank of the Timber Mountain caldera complex within the southwest Nevada volcanic field. Miocene tuffs and lavas of the Calico Hills Formation, the Paintbrush Group, and the Timber Mountain Group crop out in the area of this map. The source vents of the tuff cones and lava domes commonly are located beneath the thickest deposits of pyroclastic ejecta and lava flows. The rocks within the mapped area have been deformed by north- and northwest-striking, dominantly west-dipping normal faults and a few east-dipping normal faults. Faults commonly are characterized by well developed fault scarps, thick breccia zones, and hanging-wall grabens. Latest movement as preserved by slickensides on west-dipping fault scarps is oblique down towards the southwest. Two of these faults, the Paintbrush Canyon fault and the Bow Ridge fault, are major block-bounding faults here and to the south at Yucca Mountain. Offset of stratigraphic units across faults indicates that faulting occurred throughout the time these volcanic units were deposited

Geologic map of the Paintbrush Canyon Area, Yucca Mountain, Nevada

Energy Technology Data Exchange (ETDEWEB)

Dickerson, R.P. [Geological Survey, Denver, CO (United States); Drake, R.M. II [Pacific Western Technologies, Ltd., Lakewood, CO (United States)

1998-11-01

This geologic map is produced to support site characterization studies of Yucca Mountain, Nevada, site of a potential nuclear waste storage facility. The area encompassed by this map lies between Yucca Wash and Fortymile Canyon, northeast of Yucca Mountain. It is on the southern flank of the Timber Mountain caldera complex within the southwest Nevada volcanic field. Miocene tuffs and lavas of the Calico Hills Formation, the Paintbrush Group, and the Timber Mountain Group crop out in the area of this map. The source vents of the tuff cones and lava domes commonly are located beneath the thickest deposits of pyroclastic ejecta and lava flows. The rocks within the mapped area have been deformed by north- and northwest-striking, dominantly west-dipping normal faults and a few east-dipping normal faults. Faults commonly are characterized by well developed fault scarps, thick breccia zones, and hanging-wall grabens. Latest movement as preserved by slickensides on west-dipping fault scarps is oblique down towards the southwest. Two of these faults, the Paintbrush Canyon fault and the Bow Ridge fault, are major block-bounding faults here and to the south at Yucca Mountain. Offset of stratigraphic units across faults indicates that faulting occurred throughout the time these volcanic units were deposited.

Geological Identification of Seismic Source at Opak Fault Based on Stratigraphic Sections of the Southern Mountains

Directory of Open Access Journals (Sweden)

Hita Pandita

2016-08-01

Full Text Available Earthquake is one of the unpredicted natural disasters on our earth. Despite of the absence of high-accuracy method to precisely predict the occurrence of earthquake, numerous studies have been carried out by seismologists to find it. One of the efforts to address the vulnerability of a region to earthquakes is by recognizing the type of rock as the source of the earthquake. Opak Fault is an active fault which was thought to be the source of earthquakes in Yogyakarta and adjacent areas. This study aimed to determine the seismic source types of rocks in Yogyakarta and adjacent areas. The methods were by measuring stratigraphic sections and the layer thickness in the western part of Southern Mountains. Field study was done in 6 (six research sites. Results of stratigraphic measurement indicated the sedimentary rocks in the Southern Mountains was 3.823 km in thick, while the bedrock was more than 1.042 km in thick. Based on the result, the rock types as the seismic source were thought to originate from the continental crust rocks formed of granite and metamorphic complex.

Solar saddle bags. Solar-Fahrradpacktaschen

Energy Technology Data Exchange (ETDEWEB)

Willems, M

1991-09-12

The invention consists of the arrangement of solar cells on the upper side of saddle bags of every design (handle bar pocket, bicycle saddle bag etc.) which charge the accumulators in the pack pocket. One can drive the alternator of the bicycle, a transistor radio, a cassette tape recorder, or similar, with the power from the accumulators. The lamp and the taillight of the bicycle can still be used. The solar cells can be attached firmly to the pack pocket. However, they can also be assembled detachably, e.g. by push-buttons or zip-fasteners.

The Antitriangular Factorization of Saddle Point Matrices

KAUST Repository

Pestana, J.

2014-01-01

Mastronardi and Van Dooren [SIAM J. Matrix Anal. Appl., 34 (2013), pp. 173-196] recently introduced the block antitriangular ("Batman") decomposition for symmetric indefinite matrices. Here we show the simplification of this factorization for saddle point matrices and demonstrate how it represents the common nullspace method. We show that rank-1 updates to the saddle point matrix can be easily incorporated into the factorization and give bounds on the eigenvalues of matrices important in saddle point theory. We show the relation of this factorization to constraint preconditioning and how it transforms but preserves the structure of block diagonal and block triangular preconditioners. © 2014 Society for Industrial and Applied Mathematics.

Evolution of the northern santa cruz mountains by advection of crust past a san andreas fault bend.

Science.gov (United States)

Anderson, R S

1990-07-27

The late Quaternary marine terraces near Santa Cruz, California, reflect uplift associated with the nearby restraining bend on the San Andreas fault. Excellent correspondence of the coseismic vertical displacement field caused by the 17 October 1989 magnitude 7.1 Loma Prieta earthquake and the present elevations of these terraces allows calculation of maximum long-term uplift rates 1 to 2 kilometers west of the San Andreas fault of 0.8 millimeters per year. Over several million years, this uplift, in concert with the right lateral translation of the resulting topography, and with continual attack by geomorphic processes, can account for the general topography of the northern Santa Cruz Mountains.

Two-Phase Exhumation of the Santa Rosa Mountains: Low- and High-Angle Normal Faulting During Initiation and Evolution of the Southern San Andreas Fault System

Science.gov (United States)

Mason, Cody C.; Spotila, James A.; Axen, Gary; Dorsey, Rebecca J.; Luther, Amy; Stockli, Daniel F.

2017-12-01

Low-angle detachment fault systems are important elements of oblique-divergent plate boundaries, yet the role detachment faulting plays in the development of such boundaries is poorly understood. The West Salton Detachment Fault (WSDF) is a major low-angle normal fault that formed coeval with localization of the Pacific-North America plate boundary in the northern Salton Trough, CA. Apatite U-Th/He thermochronometry (AHe; n = 29 samples) and thermal history modeling of samples from the Santa Rosa Mountains (SRM) reveal that initial exhumation along the WSDF began at circa 8 Ma, exhuming footwall material from depths of >2 to 3 km. An uplifted fossil (Miocene) helium partial retention zone is present in the eastern SRM, while a deeper crustal section has been exhumed along the Pleistocene high-angle Santa Rosa Fault (SFR) to much higher elevations in the southwest SRM. Detachment-related vertical exhumation rates in the SRM were 0.15-0.36 km/Myr, with maximum fault slip rates of 1.2-3.0 km/Myr. Miocene AHe isochrons across the SRM are consistent with northeast crustal tilting of the SRM block and suggest that the post-WSDF vertical exhumation rate along the SRF was 1.3 km/Myr. The timing of extension initiation in the Salton Trough suggests that clockwise rotation of relative plate motions that began at 8 Ma is associated with initiation of the southern San Andreas system. Pleistocene regional tectonic reorganization was contemporaneous with an abrupt transition from low- to high-angle faulting and indicates that local fault geometry may at times exert a fundamental control on rock uplift rates along strike-slip fault systems.

Three-dimensional numerical modeling of the influence of faults on groundwater flow at Yucca Mountain, Nevada

Energy Technology Data Exchange (ETDEWEB)

Cohen, Andrew J.B. [Univ. of California, Berkeley, CA (United States)

1999-06-01

Numerical simulations of groundwater flow at Yucca Mountain, Nevada are used to investigate how the faulted hydrogeologic structure influences groundwater flow from a proposed high-level nuclear waste repository. Simulations are performed using a 3-D model that has a unique grid block discretization to accurately represent the faulted geologic units, which have variable thicknesses and orientations. Irregular grid blocks enable explicit representation of these features. Each hydrogeologic layer is discretized into a single layer of irregular and dipping grid blocks, and faults are discretized such that they are laterally continuous and displacement varies along strike. In addition, the presence of altered fault zones is explicitly modeled, as appropriate. The model has 23 layers and 11 faults, and approximately 57,000 grid blocks and 200,000 grid block connections. In the past, field measurement of upward vertical head gradients and high water table temperatures near faults were interpreted as indicators of upwelling from a deep carbonate aquifer. Simulations show, however, that these features can be readily explained by the geometry of hydrogeologic layers, the variability of layer permeabilities and thermal conductivities, and by the presence of permeable fault zones or faults with displacement only. In addition, a moderate water table gradient can result from fault displacement or a laterally continuous low permeability fault zone, but not from a high permeability fault zone, as others postulated earlier. Large-scale macrodispersion results from the vertical and lateral diversion of flow near the contact of high and low permeability layers at faults, and from upward flow within high permeability fault zones. Conversely, large-scale channeling can occur due to groundwater flow into areas with minimal fault displacement. Contaminants originating at the water table can flow in a direction significantly different than that of the water table gradient, and isolated

Three-dimensional numerical modeling of the influence of faults on groundwater flow at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Cohen, Andrew J.B.

1999-01-01

Numerical simulations of groundwater flow at Yucca Mountain, Nevada are used to investigate how the faulted hydrogeologic structure influences groundwater flow from a proposed high-level nuclear waste repository. Simulations are performed using a 3-D model that has a unique grid block discretization to accurately represent the faulted geologic units, which have variable thicknesses and orientations. Irregular grid blocks enable explicit representation of these features. Each hydrogeologic layer is discretized into a single layer of irregular and dipping grid blocks, and faults are discretized such that they are laterally continuous and displacement varies along strike. In addition, the presence of altered fault zones is explicitly modeled, as appropriate. The model has 23 layers and 11 faults, and approximately 57,000 grid blocks and 200,000 grid block connections. In the past, field measurement of upward vertical head gradients and high water table temperatures near faults were interpreted as indicators of upwelling from a deep carbonate aquifer. Simulations show, however, that these features can be readily explained by the geometry of hydrogeologic layers, the variability of layer permeabilities and thermal conductivities, and by the presence of permeable fault zones or faults with displacement only. In addition, a moderate water table gradient can result from fault displacement or a laterally continuous low permeability fault zone, but not from a high permeability fault zone, as others postulated earlier. Large-scale macrodispersion results from the vertical and lateral diversion of flow near the contact of high and low permeability layers at faults, and from upward flow within high permeability fault zones. Conversely, large-scale channeling can occur due to groundwater flow into areas with minimal fault displacement. Contaminants originating at the water table can flow in a direction significantly different than that of the water table gradient, and isolated

Low footwall accelerations and variable surface rupture behavior on the Fort Sage Mountains fault, northeast California

Science.gov (United States)

Briggs, Richard W.; Wesnousky, Steven G.; Brune, James N.; Purvance, Matthew D.; Mahan, Shannon

2013-01-01

The Fort Sage Mountains fault zone is a normal fault in the Walker Lane of the western Basin and Range that produced a small surface rupture (L 5.6 earthquake in 1950. We investigate the paleoseismic history of the Fort Sage fault and find evidence for two paleoearthquakes with surface displacements much larger than those observed in 1950. Rupture of the Fort Sage fault ∼5.6  ka resulted in surface displacements of at least 0.8–1.5 m, implying earthquake moment magnitudes (Mw) of 6.7–7.1. An older rupture at ∼20.5  ka displaced the ground at least 1.5 m, implying an earthquake of Mw 6.8–7.1. A field of precariously balanced rocks (PBRs) is located less than 1 km from the surface‐rupture trace of this Holocene‐active normal fault. Ground‐motion prediction equations (GMPEs) predict peak ground accelerations (PGAs) of 0.2–0.3g for the 1950 rupture and 0.3–0.5g for the ∼5.6  ka paleoearthquake one kilometer from the fault‐surface trace, yet field tests indicate that the Fort Sage PBRs will be toppled by PGAs between 0.1–0.3g. We discuss the paleoseismic history of the Fort Sage fault in the context of the nearby PBRs, GMPEs, and probabilistic seismic hazard maps for extensional regimes. If the Fort Sage PBRs are older than the mid‐Holocene rupture on the Fort Sage fault zone, this implies that current GMPEs may overestimate near‐fault footwall ground motions at this site.

Geology of the Waste Treatment Plant Seismic Boreholes

Energy Technology Data Exchange (ETDEWEB)

Barnett, D. Brent; Fecht, Karl R.; Reidel, Stephen P.; Bjornstad, Bruce N.; Lanigan, David C.; Rust, Colleen F.

2007-05-11

In 2006, the U.S. Department of Energy initiated the Seismic Boreholes Project (SBP) to emplace boreholes at the Waste Treatment Plant (WTP) site in order to obtain direct shear wave velocity (Vs) measurements and other physical property measurements in Columbia River basalt and interbedded sediments of the Ellensburg Formation. The goal was to reduce the uncertainty in the response spectra and seismic design basis, and potentially recover design margin for the WTP. The characterization effort within the deep boreholes included 1) downhole measurements of the velocity properties of the suprabasalt, basalt, and sedimentary interbed sequences, 2) downhole measurements of the density of the subsurface basalt and sediments, and 3) geologic studies to confirm the geometry of the contact between the various basalt and interbedded sediments through examination of retrieved core from the core hole and data collected through geophysical logging of each borehole. This report describes the results of the geologic studies from three mud-rotary boreholes and one cored borehole at the WTP. All four boreholes penetrated the entire Saddle Mountains Basalt and the upper part of the Wanapum Basalt where thick sedimentary interbeds occur between the lava flows. The basalt flows penetrated in Saddle Mountains Basalt included the Umatilla Member, Esquatzel Member, Pomona Member, and the Elephant Mountain Member. The underlying Priest Rapids Member of the Wanapum Basalt also was penetrated. The Ellensburg Formation sediments consist of the Mabton Interbed, the Cold Creek Interbed, the Selah Interbed, and the Rattlesnake Ridge Interbed; the Byron Interbed occurs between two flows of the Priest Rapids Member. The Mabton Interbed marks the contact between the Wanapum and Saddle Mountains Basalts. The thicknesses of the basalts and interbedded sediments were within expected limits. However, a small reverse fault was found in the Pomona Member flow top. This fault has three periods of

Geology of the Waste Treatment Plant Seismic Boreholes

Energy Technology Data Exchange (ETDEWEB)

Barnett, D. BRENT; Bjornstad, Bruce N.; Fecht, Karl R.; Lanigan, David C.; Reidel, Steve; Rust, Colleen F.

2007-02-28

In 2006, DOE-ORP initiated the Seismic Boreholes Project (SBP) to emplace boreholes at the Waste Treatment Plant (WTP) site in order to obtain direct Vs measurements and other physical property measurements in Columbia River basalt and interbedded sediments of the Ellensburg Formation. The goal was to reduce the uncertainty in the response spectra and seismic design basis, and potentially recover design margin for the WTP. The characterization effort within the deep boreholes included 1) downhole measurements of the velocity properties of the suprabasalt, basalt, and sedimentary interbed sequences, 2) downhole measurements of the density of the subsurface basalt and sediments, and 3) confirmation of the geometry of the contact between the various basalt and interbedded sediments through examination of retrieved core from the corehole and data collected through geophysical logging of each borehole. This report describes the results of the geologic studies from three mud-rotary boreholes and one cored borehole at the WTP. All four boreholes penetrated the entire Saddle Mountains Basalt and the upper part of the Wanapum Basalt where thick sedimentary interbeds occur between the lava flows. The basalt flows penetrated in Saddle Mountains Basalt included the Umatilla Member, Esquatzel Member, Pomona Member and the Elephant Mountain Member. The underlying Priest Rapids Member of the Wanapum Basalt was also penetrated. The Ellensburg Formation sediments consist of the Mabton Interbed, the Cold Creek Interbed, the Selah Interbed and the Rattlesnake Ridge Interbed; the Byron Interbed occurs between two flows of the Priest Rapids Member. The Mabton Interbed marks the contact between the Wanapum and Saddle Mountains Basalts. The thicknesses of the basalts and interbedded sediments were within expected limits. However, a small reverse fault was found in the Pomona Member flow top. This fault has three periods of movement and less than 15 feet of repeated section. Most of the

FABRICATION OF WINDOW SADDLES FOR NIF CRYOGENIC HOHLRAUMS

International Nuclear Information System (INIS)

GIRALDEZ, E; KAAE, J.L

2003-09-01

OAK-B135 A planar diagnostic viewing port attached to the cylindrical wall of the NIF cryogenic hohlraum requires a saddle-like transition piece. While the basic design of this window saddle is straightforward, its fabrication is not, given the scale and precision of the component. They solved the problem through the use of a two segment copper mandrel to electroform the gold window saddle. The segments were micro-machined using a combination of single-point diamond turning and single point diamond milling. These processes as well as the electroplating conditions, final machining and mandrel removal are described in this paper

The effect of saddle design on stresses in the perineum during cycling.

Science.gov (United States)

Spears, Iain R; Cummins, Neil K; Brenchley, Zoe; Donohue, Claire; Turnbull, Carli; Burton, Shona; Macho, Gabrielle A

2003-09-01

Repetitive internal stress in the perineum has been associated with soft-tissue trauma in bicyclists. Using an engineering approach, the purpose of this study was to quantify the amount of compression exerted in the perineum for a range of saddle widths and orientations. Computer tomography was used to create a three-dimensional voxel-based finite element model of the right side of the male perineum-pelvis. For the creation of the saddle model, a commercially available saddle was digitized and the surface manipulated to represent a variety of saddle widths and orientations. The two models were merged, and a static downward load of 189 N was applied to the model at the region representing the sacroiliac joint. For validation purposes, external stresses along the perineum-saddle interface were compared with the results of pressure sensitive film. Good agreement was found for these external stresses. The saddles were then stretched and rotated, and the magnitude and location of maximum stresses within the perineum were both recorded. In all cases, the model of the pelvis-perineum was held in an upright position. Stresses within the perineum were reduced when the saddle was sufficiently wide to support both ischial tuberosities. This supporting mechanism was best achieved when the saddle was at least two times wider than the bi-ischial width of the cyclist. Stresses in the anterior of the perineum were reduced when the saddle was tilted downward, whereas stresses in the posterior were reduced when the saddle was tilted upward. Recommendations that saddles should be sufficiently wide to support the ischial tuberosities appear to be well founded. Recommendations that saddles be tilted downward (i.e., nose down) are supported by the model, but with caution, given the limitations of the model.

Gravity and magnetic data across the Ghost Dance Fault in WT-2 Wash, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Oliver, H.W.; Sikora, R.F.

1994-01-01

Detailed gravity and ground magnetic data were obtained in September 1993 along a 4,650 ft-long profile across the Ghost Dance Fault system in WT-2 Wash. Gravity stations were established every 150 feet along the profile. Total-field magnetic measurements made initially every 50 ft along the profile, then remade every 20 ft through the fault zone. These new data are part of a geologic and geophysical study of the Ghost Dance Fault (GDF) which includes detailed geologic mapping, seismic reflection, and some drilling including geologic and geophysical logging. The Ghost Dance Fault is the only through-going fault that has been identified within the potential repository for high-level radioactive waste at Yucca Mountain, Nevada. Preliminary gravity results show a distinct decrease of 0.1 to 0.2 mGal over a 600-ft-wide zone to the east of and including the mapped fault. The gravity decrease probably marks a zone of brecciation. Another fault-offset located about 2,000 ft to the east of the GDF was detected by seismic reflection data and is also marked by a distinct gravity low. The ground magnetic data show a 200-ft-wide magnetic low of about 400 nT centered about 100 ft east of the Ghost Dance Fault. The magnetic low probably marks a zone of brecciation within the normally polarized Topopah Spring Tuff, the top of which is about 170 ft below the surface, and which is known from drilling to extend to a depth of about 1,700 ft. Three-component magnetometer logging in drill hole WT-2 located about 2,700 ft east of the Ghost Dance Fault shows that the Topopah Spring Tuff is strongly polarized magnetically in this area, so that fault brecciation of a vertical zone within the Tuff could provide an average negative magnetic contrast of the 4 Am -1 needed to produce the 400 nT low observed at the surface

Identifying Septal Support Reconstructions for Saddle Nose Deformity: The Cakmak Algorithm.

Science.gov (United States)

Cakmak, Ozcan; Emre, Ismet Emrah; Ozkurt, Fazil Emre

2015-01-01

The saddle nose deformity is one of the most challenging problems in nasal surgery with a less predictable and reproducible result than other nasal procedures. The main feature of this deformity is loss of septal support with both functional and aesthetic implications. Most reports on saddle nose have focused on aesthetic improvement and neglected the reestablishment of septal support to improve airway. To explain how the Cakmak algorithm, an algorithm that describes various fixation techniques and grafts in different types of saddle nose deformities, aids in identifying saddle nose reconstructions that restore supportive nasal framework and provide the aesthetic improvements typically associated with procedures to correct saddle nose deformities. This algorithm presents septal support reconstruction of patients with saddle nose deformity based on the experience of the senior author in 206 patients with saddle nose deformity. Preoperative examination, intraoperative assessment, reconstruction techniques, graft materials, and patient evaluation of aesthetic success were documented, and 4 different types of saddle nose deformities were defined. The Cakmak algorithm classifies varying degrees of saddle nose deformity from type 0 to type 4 and helps identify the most appropriate surgical procedure to restore the supportive nasal framework and aesthetic dorsum. Among the 206 patients, 110 women and 96 men, mean (range) age was 39.7 years (15-68 years), and mean (range) of follow-up was 32 months (6-148 months). All but 12 patients had a history of previous nasal surgeries. Application of the Cakmak algorithm resulted in 36 patients categorized with type 0 saddle nose deformities; 79, type 1; 50, type 2; 20, type 3a; 7, type 3b; and 14, type 4. Postoperative photographs showed improvement of deformities, and patient surveys revealed aesthetic improvement in 201 patients and improvement in nasal breathing in 195 patients. Three patients developed postoperative infection

Differentiating simple and composite tectonic landscapes using numerical fault slip modeling with an example from the south central Alborz Mountains, Iran

KAUST Repository

Landgraf, A.

2013-09-01

The tectonically driven growth of mountains reflects the characteristics of the underlying fault systems and the applied tectonic forces. Over time, fault networks might be relatively static, but stress conditions could change and result in variations in fault slip orientation. Such a tectonic landscape would transition from a “simple” to a “composite” state: the topography of simple landscapes is correlated with a single set of tectonic boundary conditions, while composite landscapes contain inherited topography due to earlier deformation under different boundary conditions. We use fault interaction modeling to compare vertical displacement fields with topographic metrics to differentiate the two types of landscapes. By successively rotating the axis of maximum horizontal stress, we produce a suite of vertical displacement fields for comparison with real landscapes. We apply this model to a transpressional duplex in the south central Alborz Mountains of Iran, where NW oriented compression was superseded by neotectonic NE compression. The consistency between the modeled displacement field and real landforms indicates that the duplex topography is mostly compatible with the modern boundary conditions, but might include a small remnant from the earlier deformation phase. Our approach is applicable for various tectonic settings and represents an approach to identify the changing boundary conditions that produce composite landscapes. It may be particularly useful for identifying changes that occurred in regions where river profiles may no longer record a signal of the change or where the spatial pattern of uplift is complex.

Differentiating simple and composite tectonic landscapes using numerical fault slip modeling with an example from the south central Alborz Mountains, Iran

KAUST Repository

Landgraf, A.; Zielke, Olaf; Arrowsmith, J. R.; Ballato, P.; Strecker, M. R.; Schildgen, T. F.; Friedrich, A. M.; Tabatabaei, S. H.

2013-01-01

The tectonically driven growth of mountains reflects the characteristics of the underlying fault systems and the applied tectonic forces. Over time, fault networks might be relatively static, but stress conditions could change and result in variations in fault slip orientation. Such a tectonic landscape would transition from a “simple” to a “composite” state: the topography of simple landscapes is correlated with a single set of tectonic boundary conditions, while composite landscapes contain inherited topography due to earlier deformation under different boundary conditions. We use fault interaction modeling to compare vertical displacement fields with topographic metrics to differentiate the two types of landscapes. By successively rotating the axis of maximum horizontal stress, we produce a suite of vertical displacement fields for comparison with real landscapes. We apply this model to a transpressional duplex in the south central Alborz Mountains of Iran, where NW oriented compression was superseded by neotectonic NE compression. The consistency between the modeled displacement field and real landforms indicates that the duplex topography is mostly compatible with the modern boundary conditions, but might include a small remnant from the earlier deformation phase. Our approach is applicable for various tectonic settings and represents an approach to identify the changing boundary conditions that produce composite landscapes. It may be particularly useful for identifying changes that occurred in regions where river profiles may no longer record a signal of the change or where the spatial pattern of uplift is complex.

Characterization of Quaternary and suspected Quaternary faults, regional studies, Nevada and California

Energy Technology Data Exchange (ETDEWEB)

Anderson, R.E.; Bucknam, R.C.; Crone, A.J.; Haller, K.M.; Machette, M.N.; Personius, S.F.; Barnhard, T.P.; Cecil, M.J.; Dart, R.L.

1995-12-31

This report presents the results of geologic studies that help define the Quaternary history of selected faults in the region around Yucca Mountain, Nevada. These results are relevant to the seismic-design basis of a potential nuclear waste repository at Yucca Mountain. The relevancy is based, in part, on a need for additional geologic data that became apparent in ongoing studies that resulted in the identification of 51 relevant and potentially relevant individual and compound faults and fault zones in the 100-km-radius region around the Yucca Mountain site. Geologic data used to characterize the regional faults and fault zones as relevant or potentially relevant seismic sources includes age and displacement information, maximum fault lengths, and minimum distances between the fault and the Yucca Mountain site. For many of the regional faults, no paleoseismic field studies have previously been conducted, and age and displacement data are sparse to nonexistent. In November 1994, the Branch of Earthquake and Landslide Hazards entered into two Memoranda of Agreement with the Yucca Mountain Project Branch to conduct field reconnaissance, analysis, and interpretation of six relevant and six potentially relevant regional faults. This report describes the results of study of those faults exclusive of those in the Pahrump-Stewart Valley-Ash Meadows-Amargosa Valley areas. We also include results of a cursory study of faults on the west flank of the Specter Range and in the northern part of the Last Chance Range. A four-phase strategy was implemented for the field study.

MIT-Skywalker: Evaluating comfort of bicycle/saddle seat.

Science.gov (United States)

Goncalves, Rogerio S; Hamilton, Taya; Daher, Ali R; Hirai, Hiroaki; Krebs, Hermano I

2017-07-01

The MIT-Skywalker is a robotic device developed for the rehabilitation of gait and balance after a neurological injury. This device has been designed based on the concept of a passive walker and provides three distinct training modes: discrete movement, rhythmic movement, and balance training. In this paper, we present our efforts to evaluate the comfort of a bicycle/saddle seat design for the system's novel actuated body weight support device. We employed different bicycle and saddle seats and evaluated comfort using objective and subjective measures. Here we will summarize the results obtained from a study of fifteen healthy subjects and one stroke patient that led to the selection of a saddle seat design for the MIT-Skywalker.

Effect of bicycle saddle designs on the pressure to the perineum of the bicyclist.

Science.gov (United States)

Lowe, Brian D; Schrader, Steven M; Breitenstein, Michael J

2004-06-01

Increasing awareness of an association between bicycling and male sexual dysfunction has led to the appearance of a variety of bicycle saddles that share the design objective of reducing pressure in the groin of the cyclist by removal of the narrow protruding nose of the saddle. This study compared three of these saddle designs to a traditional sport/road racing saddle with a narrow protruding nose in terms of pressure in the region of the perineum (groin) of the cyclist. Saddle, pedal, and handlebar contact pressure were measured from 33 bicycle police patrol officers pedaling a stationary bicycle at a controlled cadence and workload. Pressure was characterized over the saddle as a whole and over a region of the saddle assumed to represent pressure on the cyclist's perineum located anteriorly to the ischial tuberosities. The traditional sport/racing saddle was associated with more than two times the pressure in the perineal region than the saddles without a protruding nose (P perineum of the bicyclist.

Slingram survey at Yucca Mountain on the Nevada Test Site

International Nuclear Information System (INIS)

Flanigan, V.J.

1981-01-01

Electromagnetic (EM) data presented in this report is part of study by the US Geological Survey aimed at evaluating the Miocene and Pliocene Yucca Mountain Member of various units of the Paintbrush Tuff in the vicinity of Yucca Mountain as a possible repository for nuclear wastes. The survey area is located about 97 km northwest of Las Vegas, Nevada on the Nevada Test Site. Data contained in this report were taken along the eastern edge of Yucca Mountain. The specific purpose of this survey was to determine with EM methods, whether or not northwest-trending valleys in the Yucca Mountain area were fault controlled. Fault and fracture zones in the tuff units were expected to have a somewhat higher conductivity than the unfractured tuff. This is due to the greater porosity, clay and moisture content expected in the fault zones than in unfaulted rock. Depending upon a number of factors, such as the conductivity contrast between fault zones and unfaulted rock, and the depth and conductivity of the overburden, it may be possible to recognize fault zones from surface EM measurements. Several EM methods were tested to determine which one gave the best results in this environment. The methods tried included slingram, Turam and VLF (very low frequency). Slingram data proved to be most diagnostic in delineating a mapped fault on the east edge of Yucca Mountain, and hence was used in the survey traverses crossing the northwest valleys cutting into Yucca Mountain

Complex saddle points in QCD at finite temperature and density

Science.gov (United States)

Nishimura, Hiromichi; Ogilvie, Michael C.; Pangeni, Kamal

2014-08-01

The sign problem in QCD at finite temperature and density leads naturally to the consideration of complex saddle points of the action or effective action. The global symmetry CK of the finite-density action, where C is charge conjugation and K is complex conjugation, constrains the eigenvalues of the Polyakov loop operator P at a saddle point in such a way that the action is real at a saddle point, and net color charge is zero. The values of TrFP and TrFP† at the saddle point are real but not identical, indicating the different free energy cost associated with inserting a heavy quark versus an antiquark into the system. At such complex saddle points, the mass matrix associated with Polyakov loops may have complex eigenvalues, reflecting oscillatory behavior in color-charge densities. We illustrate these properties with a simple model which includes the one-loop contribution of gluons and two flavors of massless quarks moving in a constant Polyakov loop background. Confinement-deconfinement effects are modeled phenomenologically via an added potential term depending on the Polyakov loop eigenvalues. For sufficiently large temperature T and quark chemical potential μ, the results obtained reduce to those of perturbation theory at the complex saddle point. These results may be experimentally relevant for the compressed baryonic matter experiment at FAIR.

Regularization of the Boundary-Saddle-Node Bifurcation

Directory of Open Access Journals (Sweden)

Xia Liu

2018-01-01

Full Text Available In this paper we treat a particular class of planar Filippov systems which consist of two smooth systems that are separated by a discontinuity boundary. In such systems one vector field undergoes a saddle-node bifurcation while the other vector field is transversal to the boundary. The boundary-saddle-node (BSN bifurcation occurs at a critical value when the saddle-node point is located on the discontinuity boundary. We derive a local topological normal form for the BSN bifurcation and study its local dynamics by applying the classical Filippov’s convex method and a novel regularization approach. In fact, by the regularization approach a given Filippov system is approximated by a piecewise-smooth continuous system. Moreover, the regularization process produces a singular perturbation problem where the original discontinuous set becomes a center manifold. Thus, the regularization enables us to make use of the established theories for continuous systems and slow-fast systems to study the local behavior around the BSN bifurcation.

Modeling Temporal-Spatial Earthquake and Volcano Clustering at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

T. Parsons; G.A. Thompson; A.H. Cogbill

2006-01-01

The proposed national high-level nuclear repository at Yucca Mountain is close to Quaternary faults and cinder cones. The frequency of these events is low, with indications of spatial and temporal clustering, making probabilistic assessments difficult. In an effort to identify the most likely intrusion sites, we based a 3D finite element model on the expectation that faulting and basalt intrusions are primarily sensitive to the magnitude and orientation of the least principal stress in extensional terranes. We found that in the absence of fault slip, variation in overburden pressure caused a stress state that preferentially favored intrusions at Crater Flat. However, when we allowed central Yucca Mountain faults to slip in the model, we found that magmatic clustering was not favored at Crater Flat or in the central Yucca Mountain block. Instead, we calculated that the stress field was most encouraging to intrusions near fault terminations, consistent with the location of the most recent volcanism at Yucca Mountain, the Lathrop Wells cone. We found this linked fault and magmatic system to be mutually reinforcing in the model in that dike inflation favored renewed fault slip

Very high geothermal gradient in near surface of the Whataroa Valley adjacent to the Alpine Fault: topographic driving forces and permeable mountains

Science.gov (United States)

Upton, P.; Sutherland, R.; Townend, J.; Coussens, J.; Capova, L.

2015-12-01

The first phase of the Deep Fault Drilling Project (DFDP-1B) yielded a geothermal gradient of 62.6 ± 2.1 °C/km from a depth of 126 m where it intersected the Alpine Fault principal slip surface beneath Gaunt Creek (Sutherland et al. 2012). Ambient fluid pressures in DFDP-2B at Whataroa River were 8-10% above hydrostatic and a geothermal gradient of >130°C/km was determined, the geothermal gradient being considerably higher than we had predicted previously. 3D coupled thermal/fluid flow models have been generated of the Whataroa Valley and the DFDP-2 drill site. Modelling confirms that the following features, present in the Whataroa Valley, are a requirement for a geothermal gradient of >130°C/km at a depth of 1km beneath the valley; high topography, permeability on the order of 10-15 m2 in both the mountains and beneath the valleys to depths of > 1km below the valley floor, and abundant fluid. The high permeability and large topographic driving force leads to abundant meteoric water flowing downward through the mountains, hitting the permeability barrier of the Alpine Fault and being pushed upward into the valleys. The high geothermal gradient of the DFDP-2B borehole implies that the valleys also have a very high permeability which is likely a result of rock damage along the Alpine Fault.

Active faults paragenesis and the state of crustal stresses in the Late Cenozoic in Central Mongolia

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V. A. Sankov

2015-01-01

Full Text Available Active faults of the Hangay-Hentiy tectonic saddle region in Central Mongolia are studied by space images interpretation, relief analysis, structural methods and tectonic stress reconstruction. The study results show that faults activation during the Late Cenozoic stage was selective, and a cluster pattern of active faults is typical for the study region. Morphological and genetic types and the kinematics of faults in the Hangay-Hentiy saddle region are related the direction of the ancient inherited structural heterogeneities. Latitudinal and WNW trending faults are left lateral strike-slips with reverse or thrust component (Dzhargalantgol and North Burd faults. NW trending faults are reverse faults or thrusts with left lateral horizontal component. NNW trending faults have right lateral horizontal component. The horizontal component of the displacements, as a rule, exceeds the vertical one. Brittle deformations in fault zones do not conform with the Pliocene and, for the most part, Pleistocene topography. With some caution it may be concluded that the last phase of revitalization of strike slip and reverse movements along the faults commenced in the Late Pleistocene. NE trending disjunctives are normal faults distributed mainly within the Hangay uplift. Their features are more early activation within the Late Cenozoic and the lack of relation to large linear structures of the previous tectonic stages. According to the stress tensor reconstructions of the last phase of deformation in zones of active faults of the Hangay-Hentiy saddle using data on tectonic fractures and fault displacements, it is revealed that conditions of compression and strike-slip with NNE direction of the axis of maximum compression were dominant. Stress tensors of extensional type with NNW direction of minimum compression are reconstructed for the Orkhon graben. It is concluded that the activation of faults in Central Mongolia in the Pleistocene-Holocene, as well as

Numerical seismic modelling of fault-fold structures in a mountainous setting

Energy Technology Data Exchange (ETDEWEB)

Kirtland Grech, M.G.; Lawton, D.C.; Spratt, D.A. (Calgary Univ., AB (Canada))

1999-01-01

Experiments were conducted to determine the performance of different prestack migration algorithms in complex structural areas, particularly in the presence of rugged topography and thrust faults that result in severe lateral and vertical velocity changes, using a series of numerical seismic models. The numerical model used was based on a cross section through the Rocky Mountains Front Ranges of Western Canada and is 33 km wide and 11 km deep. The best migrated section was obtained with FD shot migration in depth and from topography, using the known velocity model. This result was superior to Kirchhoff depth migration from topography and from a flat datum. As the velocities departed from their true value, the deeper events were most affected, because of the accumulation of velocity errors with depth. The small-scale features of Target A, in the shallower part of the section, could still be interpreted even when the velocities were inaccurate. In the presence of velocity errors, the different structures could still be interpreted, but were at the wrong depth and had the wrong structural shape and size. Layers that were of the order of 1 km in width and 500 km in thickness, such as Layer 4, were the most poorly imaged and focussed, both with time migration and with depth migration. Fault planes were not imaged in the absence of a velocity contrast across them, making some FW cutoffs difficult to interpret. 2 refs.

Numerical seismic modelling of fault-fold structures in a mountainous setting

Energy Technology Data Exchange (ETDEWEB)

Kirtland Grech, M.G.; Lawton, D.C.; Spratt, D.A. [Calgary Univ., AB (Canada)

1999-11-01

Experiments were conducted to determine the performance of different prestack migration algorithms in complex structural areas, particularly in the presence of rugged topography and thrust faults that result in severe lateral and vertical velocity changes, using a series of numerical seismic models. The numerical model used was based on a cross section through the Rocky Mountains Front Ranges of Western Canada and is 33 km wide and 11 km deep. The best migrated section was obtained with FD shot migration in depth and from topography, using the known velocity model. This result was superior to Kirchhoff depth migration from topography and from a flat datum. As the velocities departed from their true value, the deeper events were most affected, because of the accumulation of velocity errors with depth. The small-scale features of Target A, in the shallower part of the section, could still be interpreted even when the velocities were inaccurate. In the presence of velocity errors, the different structures could still be interpreted, but were at the wrong depth and had the wrong structural shape and size. Layers that were of the order of 1 km in width and 500 km in thickness, such as Layer 4, were the most poorly imaged and focussed, both with time migration and with depth migration. Fault planes were not imaged in the absence of a velocity contrast across them, making some FW cutoffs difficult to interpret. 2 refs.

Decreasing Slip Rates From 12.8 Ma to Present on the Solitario Canyon Fault at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

D. Buesch

2006-01-01

The Solitario Canyon fault, which bounds the west side of Yucca Mountain, Nevada, is the closest fault with Quaternary offset adjacent to the proposed spent nuclear fuel and high-level radioactive waste repository. Dip-slip offset between 12.8 and 10.7 Ma is determined from lithostratigraphic displacement in boreholes USW H-3 and USW WT-7, drilled in the footwall and hanging wall, respectively. The base of the 12.8-Ma Topopah Spring Tuff is interpreted to have 463.3 m of separation across the fault, an average dip slip rate of 0.036 mm/yr. Previous researchers identified a geothermal system active from 11.5 to 10.0 Ma with peak activity at 10.7 Ma that resulted in pervasive alteration of vitric rock to zeolitic minerals where the rocks were in the ground-water saturated zone. The contact between vitric (V) and pervasively zeolitic (Z) rocks cuts across the lithostratigraphic section and offset of this V-Z boundary can be used to measure slip rates between 12.8 and 10.7 Ma. In H-3, the V-Z boundary is 138.4 m below the base of the vitric, densely welded subzone of the Topopah Spring Tuff (Tptpv3). In WT-7, although the V-Z boundary is identified at the base of the Tptpv3, borehole video, cuttings, and geophysical log data indicate the Tptpv3 has well-developed zeolitic alteration along fractures, and this implies 19.5 m of the total thickness of Tptpv3 (and probably additional overlying crystallized rocks) also were in the saturated zone by 10.7 Ma. The V-Z relations across the Solitario Canyon fault in H-3 and WT-7 indicate a minimum of 157.9 m of separation before 10.7 Ma, which is 34.1 percent of the total slip of the Topopah Spring Tuff, and a minimum dip slip rate of 0.075 mm/yr from 12.8 to 10.7 Ma. These data are consistent with the broader structural history of the area near Yucca Mountain. Previous workers used angular unconformities, tilting of structural blocks, and paleomagnetic data to constrain the main period of extensional faulting between 12.7 and 8

Time delays across saddles as a test of modified gravity

International Nuclear Information System (INIS)

Magueijo, João; Mozaffari, Ali

2013-01-01

Modified gravity theories can produce strong signals in the vicinity of the saddles of the total gravitational potential. In a sub-class of these models, this translates into diverging time delays for echoes crossing the saddles. Such models arise from the possibility that gravity might be infrared divergent or confined, and if suitably designed they are very difficult to rule out. We show that Lunar Laser Ranging during an eclipse could probe the time-delay effect within metres of the saddle, thereby proving or excluding these models. Very Large Baseline Interferometry, instead, could target delays across the Jupiter–Sun saddle. Such experiments would shed light on the infrared behaviour of gravity and examine the puzzling possibility that there might be well-hidden regions of strong gravity and even singularities inside the solar system. (fast track communication)

Electrons at the monkey saddle: A multicritical Lifshitz point

Science.gov (United States)

Shtyk, A.; Goldstein, G.; Chamon, C.

2017-01-01

We consider two-dimensional interacting electrons at a monkey saddle with dispersion ∝px3-3 pxpy2 . Such a dispersion naturally arises at the multicritical Lifshitz point when three Van Hove saddles merge in an elliptical umbilic elementary catastrophe, which we show can be realized in biased bilayer graphene. A multicritical Lifshitz point of this kind can be identified by its signature Landau level behavior Em∝(Bm ) 3 /2 and related oscillations in thermodynamic and transport properties, such as de Haas-Van Alphen and Shubnikov-de Haas oscillations, whose period triples as the system crosses the singularity. We show, in the case of a single monkey saddle, that the noninteracting electron fixed point is unstable to interactions under the renormalization-group flow, developing either a superconducting instability or non-Fermi-liquid features. Biased bilayer graphene, where there are two non-nested monkey saddles at the K and K' points, exhibits an interplay of competing many-body instabilities, namely, s -wave superconductivity, ferromagnetism, and spin- and charge-density waves.

Assessment of saddle-point-mass predictions for astrophysical applications

Energy Technology Data Exchange (ETDEWEB)

Kelic, A.; Schmidt, K.H.

2005-07-01

Using available experimental data on fission barriers and ground-state masses, a detailed study on the predictions of different models concerning the isospin dependence of saddle-point masses is performed. Evidence is found that several macroscopic models yield unrealistic saddle-point masses for very neutron-rich nuclei, which are relevant for the r-process nucleosynthesis. (orig.)

Divided Saddle Theory: A New Idea for Rate Constant Calculation.

Science.gov (United States)

Daru, János; Stirling, András

2014-03-11

We present a theory of rare events and derive an algorithm to obtain rates from postprocessing the numerical data of a free energy calculation and the corresponding committor analysis. The formalism is based on the division of the saddle region of the free energy profile of the rare event into two adjacent segments called saddle domains. The method is built on sampling the dynamics within these regions: auxiliary rate constants are defined for the saddle domains and the absolute forward and backward rates are obtained by proper reweighting. We call our approach divided saddle theory (DST). An important advantage of our approach is that it requires only standard computational techniques which are available in most molecular dynamics codes. We demonstrate the potential of DST numerically on two examples: rearrangement of alanine-dipeptide (CH3CO-Ala-NHCH3) conformers and the intramolecular Cope reaction of the fluxional barbaralane molecule.

GEODESIC RECONSTRUCTION, SADDLE ZONES & HIERARCHICAL SEGMENTATION

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Serge Beucher

2011-05-01

Full Text Available The morphological reconstruction based on geodesic operators, is a powerful tool in mathematical morphology. The general definition of this reconstruction supposes the use of a marker function f which is not necessarily related to the function g to be built. However, this paper deals with operations where the marker function is defined from given characteristic regions of the initial function f, as it is the case, for instance, for the extrema (maxima or minima but also for the saddle zones. Firstly, we show that the intuitive definition of a saddle zone is not easy to handle, especially when digitised images are involved. However, some of these saddle zones (regional ones also called overflow zones can be defined, this definition providing a simple algorithm to extract them. The second part of the paper is devoted to the use of these overflow zones as markers in image reconstruction. This reconstruction provides a new function which exhibits a new hierarchy of extrema. This hierarchy is equivalent to the hierarchy produced by the so-called waterfall algorithm. We explain why the waterfall algorithm can be achieved by performing a watershed transform of the function reconstructed by its initial watershed lines. Finally, some examples of use of this hierarchical segmentation are described.

The Sun-Earth saddle point: characterization and opportunities to test general relativity

Science.gov (United States)

Topputo, Francesco; Dei Tos, Diogene A.; Rasotto, Mirco; Nakamiya, Masaki

2018-04-01

The saddle points are locations where the net gravitational accelerations balance. These regions are gathering more attention within the astrophysics community. Regions about the saddle points present clean, close-to-zero background acceleration environments where possible deviations from General Relativity can be tested and quantified. Their location suggests that flying through a saddle point can be accomplished by leveraging highly nonlinear orbits. In this paper, the geometrical and dynamical properties of the Sun-Earth saddle point are characterized. A systematic approach is devised to find ballistic orbits that experience one or multiple passages through this point. A parametric analysis is performed to consider spacecraft initially on L_{1,2} Lagrange point orbits. Sun-Earth saddle point ballistic fly-through trajectories are evaluated and classified for potential use. Results indicate an abundance of short-duration, regular solutions with a variety of characteristics.

Developments of saddle field ion sources and their applications

International Nuclear Information System (INIS)

Abdelrahman, M.M.; Helal, A.G.

2009-01-01

Ion sources should have different performance parameters according to the various applications for which they are used, ranging from ion beam production to high energy ion implanters. There are many kinds of ion sources, which produce different ion beams with different characteristics. This paper deals with the developments and applications of some saddle field ion sources which were designed and constructed in our lab. Theory of operation and types of saddle field ion sources are discussed in details. Some experimental results are given. The saddle field ion sources operate at low gas pressure and require neither magnetic field nor filament. This type of ion sources is used for many different applications as ion beam machining, sputtering, cleaning and profiling for surface analysis etc

19 CFR 148.32 - Vehicles, aircraft, boats, teams and saddle horses taken abroad.

Science.gov (United States)

2010-04-01

... 19 Customs Duties 2 2010-04-01 2010-04-01 false Vehicles, aircraft, boats, teams and saddle horses... for Returning Residents § 148.32 Vehicles, aircraft, boats, teams and saddle horses taken abroad. (a) Admission free of duty. Automobiles and other vehicles, aircraft, boats, teams and saddle horses, together...

Maximal saddle solution of a nonlinear elliptic equation involving the ...

Indian Academy of Sciences (India)

College of Mathematics and Econometrics, Hunan University, Changsha 410082, China. E-mail: huahuiyan@163.com; duzr@hnu.edu.cn. MS received 3 September 2012; revised 20 December 2012. Abstract. A saddle solution is called maximal saddle solution if its absolute value is not smaller than those absolute values ...

Magnetic investigations along selected high-resolution seismic traverses in the central block of Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Ponce, D.A.; Sikora, R.F.; Roberts, C.W.; Morin, R.L.; Halvorson, P.F.

1995-01-01

Ground magnetic data collected along several traverses across the central block of Yucca Mountain in southwest Nevada are interpreted. These data were collected as part of an effort to evaluate faulting in the vicinity of a potential nuclear waste repository at Yucca Mountain. Magnetic data and models along traverses across the central block of Yucca Mountain reveal anomalies associated with known faults and indicate a number of possible concealed faults beneath the eastern flank of Yucca Mountain. The central part of the eastern flank of Yucca Mountain is characterized by numerous small-amplitude anomalies that probably reflect small-scale faulting. Magnetic modeling of the terrain along the eastern flank of Yucca Mountain indicates that terrain induced magnetic anomalies of about 100 to 150 nT are present along some profiles where steep terrain exists above the magnetometer

Photomosaics and event evidence from the Frazier Mountain paleoseismic site, trench 1, cuts 1–4, San Andreas Fault Zone, southern California (2007–2009)

Science.gov (United States)

Scharer, Katherine M.; Fumal, Tom E.; Weldon, Ray J.; Streig, Ashley R.

2014-01-01

The Frazier Mountain paleoseismic site is located at the northwest end of the Mojave section of the San Andreas Fault, in a small, closed depression at the base of Frazier Mountain near Tejon Pass, California (lat 34.8122° N., long 118.9034° W.). The site was known to contain a good record of earthquakes due to previous excavations by Lindvall and others (2002). This report provides data resulting from four nested excavations, or cuts, along trench 1 (T1) in 2007 and 2009 at the Frazier Mountain site. The four cuts were excavated progressively deeper and wider in an orientation perpendicular to the San Andreas Fault, exposing distal fan and marsh sediments deposited since ca. A.D. 1200. The results of the trenching show that earthquakes that ruptured the site have repeatedly produced a small depression or sag on the surface, which is subsequently infilled with sand and silt deposits. This report provides high-resolution photomosaics and logs for the T1 cuts, a detailed stratigraphic column for the deposits, and a table summarizing all of the evidence for ground rupturing paleoearthquakes logged in the trenches.

Implications of seismic reflection and potential field geophysical data on the structural framework of the Yucca Mountain--Crater Flat region, Nevada

International Nuclear Information System (INIS)

Brocher, T.M.; Langenheim, V.E.; Hunter, W.C.

1998-01-01

Seismic reflection and gravity profiles collected across Yucca Mountain, Nevada, together with geologic data, provide evidence against proposed active detachment faults at shallow depth along the pre-Tertiary-Tertiary contact beneath this potential repository for high-level nuclear waste. The new geophysical data show that the inferred pre-Tertiary-Tertiary contact is offset by moderate-to-high-angle faults beneath Crater Flat and Yucca Mountain, and thus this shallow surface cannot represent an active detachment surface. The reflection lines reveal that the Amargosa Desert rift zone is an asymmetric half-graben having a maximum depth of about 4 km and a width of about 25 km. The east-dipping Bare Mountain fault that bounds this graben to the west can be traced by seismic reflection data to a depth of at least 3.5 km and possibly as deep as 6 km, with a constant dip of 64 degree ± 5 degree. Along the profile the transition from east- to west-dipping faults occurs at or just west of the Solitario Canyon fault, which bounds the western side of Yucca Mountain. The interaction at depth of these east- and west-dipping faults, having up to hundreds of meters offset, is not imaged by the seismic reflection profile. Understanding potential seismic hazards at Yucca Mountain requires knowledge of the subsurface geometry of the faults near Yucca Mountain, since earthquakes generally nucleate and release the greatest amount of their seismic energy at depth. The geophysical data indicate that many fault planes near the potential nuclear waste facility dip toward Yucca Mountain, including the Bare Mountain range-front fault and several west-dipping faults east of Yucca Mountain. Thus, earthquake ruptures along these faults would lie closer to Yucca Mountain than is often estimated from their surface locations and could therefore be more damaging

Quaternary faulting in the Tatra Mountains, evidence from cave morphology and fault-slip analysis

Directory of Open Access Journals (Sweden)

Szczygieł Jacek

2015-06-01

Full Text Available Tectonically deformed cave passages in the Tatra Mts (Central Western Carpathians indicate some fault activity during the Quaternary. Displacements occur in the youngest passages of the caves indicating (based on previous U-series dating of speleothems an Eemian or younger age for those faults, and so one tectonic stage. On the basis of stress analysis and geomorphological observations, two different mechanisms are proposed as responsible for the development of these displacements. The first mechanism concerns faults that are located above the valley bottom and at a short distance from the surface, with fault planes oriented sub-parallel to the slopes. The radial, horizontal extension and vertical σ1 which is identical with gravity, indicate that these faults are the result of gravity sliding probably caused by relaxation after incision of valleys, and not directly from tectonic activity. The second mechanism is tilting of the Tatra Mts. The faults operated under WNW-ESE oriented extension with σ1 plunging steeply toward the west. Such a stress field led to normal dip-slip or oblique-slip displacements. The faults are located under the valley bottom and/or opposite or oblique to the slopes. The process involved the pre-existing weakest planes in the rock complex: (i in massive limestone mostly faults and fractures, (ii in thin-bedded limestone mostly inter-bedding planes. Thin-bedded limestones dipping steeply to the south are of particular interest. Tilting toward the N caused the hanging walls to move under the massif and not toward the valley, proving that the cause of these movements was tectonic activity and not gravity.

Bedrock geologic Map of the Central Block Area, Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

W.C. Day; C. Potter; D. Sweetkind; R.P. Dickerson; C.A. San Juan

1998-01-01

Bedrock geologic maps form the foundation for investigations that characterize and assess the viability of the potential high-level radioactive waste repository at Yucca Mountain, Nevada. As such, this map focuses on the central block at Yucca Mountain, which contains the potential repository site. The central block is a structural block of Tertiary volcanic rocks bound on the west by the Solitario Canyon Fault, on the east by the Bow Ridge Fault, to the north by the northwest-striking Drill Hole Wash Fault, and on the south by Abandoned Wash. Earlier reconnaissance mapping by Lipman and McKay (1965) provided an overview of the structural setting of Yucca Mountain and formed the foundation for selecting Yucca Mountain as a site for further investigation. They delineated the main block-bounding faults and some of the intrablock faults and outlined the zoned compositional nature of the tuff units that underlie Yucca Mountain. Scott and Bonk (1984) provided a detailed reconnaissance geologic map of favorable area at Yucca Mountain in which to conduct further site-characterization studies. Of their many contributions, they presented a detailed stratigraphy for the volcanic units, defined several other block-bounding faults, and outlined numerous intrablock faults. This study was funded by the U.S. Department of Energy Yucca Mountain Project to provide a detailed (1:6,000-scale) bedrock geologic map for the area within and adjacent to the potential repository area at Yucca Mountain, Nye County, Nevada. Prior to this study, the 1:12,000-scale map of Scott and Bonk (1984) was the primary source of bedrock geologic data for the Yucca Mountain Project. However, targeted detailed mapping within the central block at Yucca Mountain revealed structural complexities along some of the intrablock faults that were not evident at 1:12,000 (Scott and Bonk, 1984). As a result, this study was undertaken to define the character and extent of the dominant structural features in the

Evaluation of saddle and driving aptitudes in Monterufoli pony

Directory of Open Access Journals (Sweden)

Riccardo Bozzi

2010-01-01

Full Text Available The Monterufoli pony is an endangered Tuscan breed. In the 80’s began a project for the conservation of the breed and at present there are roughly 200 individuals. The equine was once utilized for saddle and driving and this study deals with the training for these two aptitudes. The mor- phologic type of the pony seems suited for saddle, in particular for children and beginners, and driving. The ponies showed developed chest, strong legs with short shanks: all these characters were useful for trot and driving. In this trial 3-4 years old never tamed Monterufoli ponies were opportunely choose and subsequently trained for saddle and driving. The ponies were submitted to the “aptitude test” for the two aptitudes and the results were good both for practical and character sides. The marks for sad- dle and driving were 8.16 and 8.06 respectively. Also the 3 ponies showed good results for the Aptitude Index: 7.60, 7.87 and 7.89. The results of the trial showed the excellent ability of the Monterufoli pony for saddle and driving. The good results of the test are important for the diffusion of the breed in the territory and in particular in horse centres and in equestrian tourism sites.

Cenozoic tectono-thermal history of the Tordrillo Mountains, Alaska: Paleocene-Eocene ridge subduction, decreasing relief, and late Neogene faulting

Science.gov (United States)

Benowitz, Jeff A.; Haeussler, Peter J.; Layer, Paul W.; O'Sullivan, Paul B.; Wallace, Wes K.; Gillis, Robert J.

2012-01-01

Topographic development inboard of the continental margin is a predicted response to ridge subduction. New thermochronology results from the western Alaska Range document ridge subduction related orogenesis. K-feldspar thermochronology (KFAT) of bedrock samples from the Tordrillo Mountains in the western Alaska Range complement existing U-Pb, 40Ar/39Ar and AFT (apatite fission track) data to provide constraints on Paleocene pluton emplacement, and cooling as well as Late Eocene to Miocene vertical movements and exhumation along fault-bounded blocks. Based on the KFAT analysis we infer rapid exhumation-related cooling during the Eocene in the Tordrillo Mountains. Our KFAT cooling ages are coeval with deposition of clastic sediments in the Cook Inlet, Matanuska Valley and Tanana basins, which reflect high-energy depositional environments. The Tordrillo Mountains KFAT cooling ages are also the same as cooling ages in the Iliamna Lake region, the Kichatna Mountains of the western Alaska Range, and Mt. Logan in the Wrangell-St. Elias Mountains, thus rapid cooling at this time encompasses a broad region inboard of, and parallel to, the continental margin extending for several hundred kilometers. We infer these cooling events and deposition of clastic rocks are related to thermal effects that track the eastward passage of a slab window in Paleocene-Eocene time related to the subduction of the proposed Resurrection-Kula spreading ridge. In addition, we conclude that the reconstructed KFATmax negative age-elevation relationship is likely related to a long period of decreasing relief in the Tordrillo Mountains.

Chaotic saddles in nonlinear modulational interactions in a plasma

International Nuclear Information System (INIS)

Miranda, Rodrigo A.; Rempel, Erico L.; Chian, Abraham C.-L.

2012-01-01

A nonlinear model of modulational processes in the subsonic regime involving a linearly unstable wave and two linearly damped waves with different damping rates in a plasma is studied numerically. We compute the maximum Lyapunov exponent as a function of the damping rates in a two-parameter space, and identify shrimp-shaped self-similar structures in the parameter space. By varying the damping rate of the low-frequency wave, we construct bifurcation diagrams and focus on a saddle-node bifurcation and an interior crisis associated with a periodic window. We detect chaotic saddles and their stable and unstable manifolds, and demonstrate how the connection between two chaotic saddles via coupling unstable periodic orbits can result in a crisis-induced intermittency. The relevance of this work for the understanding of modulational processes observed in plasmas and fluids is discussed.

Chaotic saddles in nonlinear modulational interactions in a plasma

Energy Technology Data Exchange (ETDEWEB)

Miranda, Rodrigo A. [Institute of Aeronautical Technology (ITA) and World Institute for Space Environment Research (WISER), Sao Jose dos Campos, SP 12228-900 (Brazil); National Institute for Space Research (INPE) and World Institute for Space Environment Research (WISER), P.O. Box 515, Sao Jose dos Campos, SP 12227-010 (Brazil); University of Brasilia (UnB), Gama Campus, and Plasma Physics Laboratory, Institute of Physics, Brasilia, DF 70910-900 (Brazil); Rempel, Erico L. [Institute of Aeronautical Technology (ITA) and World Institute for Space Environment Research (WISER), Sao Jose dos Campos, SP 12228-900 (Brazil); National Institute for Space Research (INPE) and World Institute for Space Environment Research (WISER), P.O. Box 515, Sao Jose dos Campos, SP 12227-010 (Brazil); Chian, Abraham C.-L. [Institute of Aeronautical Technology (ITA) and World Institute for Space Environment Research (WISER), Sao Jose dos Campos, SP 12228-900 (Brazil); National Institute for Space Research (INPE) and World Institute for Space Environment Research (WISER), P.O. Box 515, Sao Jose dos Campos, SP 12227-010 (Brazil); Observatoire de Paris, LESIA, CNRS, 92195 Meudon (France)

2012-11-15

A nonlinear model of modulational processes in the subsonic regime involving a linearly unstable wave and two linearly damped waves with different damping rates in a plasma is studied numerically. We compute the maximum Lyapunov exponent as a function of the damping rates in a two-parameter space, and identify shrimp-shaped self-similar structures in the parameter space. By varying the damping rate of the low-frequency wave, we construct bifurcation diagrams and focus on a saddle-node bifurcation and an interior crisis associated with a periodic window. We detect chaotic saddles and their stable and unstable manifolds, and demonstrate how the connection between two chaotic saddles via coupling unstable periodic orbits can result in a crisis-induced intermittency. The relevance of this work for the understanding of modulational processes observed in plasmas and fluids is discussed.

Fault activity characteristics in the northern margin of the Tibetan Plateau before the Menyuan Ms6.4 earthquake

Directory of Open Access Journals (Sweden)

Dongzhuo Xu

2016-07-01

Full Text Available Fault deformation characteristics in the northern margin of the Tibetan Plateau before the Menyuan Ms6.4 earthquake are investigated through time-series and structural geological analysis based on cross-fault observation data from the Qilian Mountain–Haiyuan Fault belt and the West Qinling Fault belt. The results indicate: 1 Group short-term abnormal variations appeared in the Qilian Mountain–Haiyuan Fault belt and the West Qinling Fault belt before the Menyuan Ms6.4 earthquake. 2 More medium and short-term anomalies appear in the middle-eastern segment of the Qilian Mountain Fault belt and the West Qinling Fault belt, suggesting that the faults' activities are strong in these areas. The faults' activities in the middle-eastern segment of the Qilian Fault belt result from extensional stress, as before the earthquake, whereas those in the West Qinling Fault belt are mainly compressional. 3 In recent years, moderate-strong earthquakes occurred in both the Kunlun Mountain and the Qilian Mountain Fault belts, and some energy was released. It is possible that the seismicity moved eastward under this regime. Therefore, we should pay attention to the West Qinling Mountain area where an Ms6–7 earthquake could occur in future.

Geologic reconnaissance of the Hot Springs Mountains, Churchill County, Nevada

Science.gov (United States)

Voegtly, Nickolas E.

1981-01-01

A geologic reconnaissance of the Hot Springs Mountains and adjacent areas, which include parts of the Brady-Hazen and the Stillwater-Soda Lake Known Geothermal Resource Areas, during June-December 1975, resulted in a reinterpretation of the nature and location of some Basin and Range faults. In addition, the late Cenozoic stratigraphy has been modified, chiefly on the basis of radiometric dates of volcanic rocks by U.S. Geological Survey personnel and others. The Hot Springs Mountains are in the western part of the Basin and Range province, which is characterized by east-west crustal extension and associated normal faulting. In the surrounding Trinity, West Humboldt, Stillwater, and Desert Mountains, Cenozoic rocks overlie ' basement ' rocks of the Paleozoic and Mesozoic age. A similar relation is inferred in the Hot Springs Mountains. Folding and faulting have taken place from the late Tertiary to the present. (USGS)

Wilshire fault: Earthquakes in Hollywood?

Science.gov (United States)

Hummon, Cheryl; Schneider, Craig L.; Yeats, Robert S.; Dolan, James F.; Sieh, Kerry E.; Huftile, Gary J.

1994-04-01

The Wilshire fault is a potentially seismogenic, blind thrust fault inferred to underlie and cause the Wilshire arch, a Quaternary fold in the Hollywood area, just west of downtown Los Angeles, California. Two inverse models, based on the Wilshire arch, allow us to estimate the location and slip rate of the Wilshire fault, which may be illuminated by a zone of microearthquakes. A fault-bend fold model indicates a reverse-slip rate of 1.5-1.9 mm/yr, whereas a three-dimensional elastic-dislocation model indicates a right-reverse slip rate of 2.6-3.2 mm/yr. The Wilshire fault is a previously unrecognized seismic hazard directly beneath Hollywood and Beverly Hills, distinct from the faults under the nearby Santa Monica Mountains.

Featured Partner: Saddle Creek Logistics Services

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This EPA fact sheet spotlights Saddle Creek Logistics as a SmartWay partner committed to sustainability in reducing greenhouse gas emissions and air pollution caused by freight transportation, partly by growing its compressed natural gas (CNG) vehicles for

Measuring the distance from saddle points and driving to locate them over quantum control landscapes

International Nuclear Information System (INIS)

Sun, Qiuyang; Riviello, Gregory; Rabitz, Herschel; Wu, Re-Bing

2015-01-01

Optimal control of quantum phenomena involves the introduction of a cost functional J to characterize the degree of achieving a physical objective by a chosen shaped electromagnetic field. The cost functional dependence upon the control forms a control landscape. Two theoretically important canonical cases are the landscapes associated with seeking to achieve either a physical observable or a unitary transformation. Upon satisfaction of particular assumptions, both landscapes are analytically known to be trap-free, yet possess saddle points at precise suboptimal J values. The presence of saddles on the landscapes can influence the effort needed to find an optimal field. As a foundation to future algorithm development and analyzes, we define metrics that identify the ‘distance’ from a given saddle based on the sufficient and necessary conditions for the existence of the saddles. Algorithms are introduced utilizing the metrics to find a control such that the dynamics arrive at a targeted saddle. The saddle distance metric and saddle-seeking methodology is tested numerically in several model systems. (paper)

Vertical axis rotation (or lack thereof) of the eastern Mongolian Altay Mountains: Implications for far-field transpressional mountain building

Science.gov (United States)

Gregory, Laura C.; Mac Niocaill, Conall; Walker, Richard T.; Bayasgalan, Gantulga; Craig, Tim J.

2018-06-01

The Altay Mountains of Western Mongolia accommodate 10-20% of the current shortening of the India-Asia collision in a transpressive regime. Kinematic models of the Altay require faults to rotate anticlockwise about a vertical axis in order to accommodate compressional deformation on the major strike slip faults that cross the region. Such rotations should be detectable by palaeomagnetic data. Previous estimates from the one existing palaeomagnetic study from the Altay, on Oligocene and younger sediments from the Chuya Basin in the Siberian Altay, indicate that at least some parts of the Altay have experienced up to 39 ± 8° of anticlockwise rotation. Here, we present new palaeomagnetic results from samples collected in Cretaceous and younger sediments in the Zereg Basin along the Har-Us-Nuur fault in the eastern Altay Mountains, Mongolia. Our new palaeomagnetic results from the Zereg Basin provide reliable declinations, with palaeomagnetic directions from 10 sites that pass a fold test and include magnetic reversals. The declinations are not significantly rotated with respect to the directions expected from Cretaceous and younger virtual geomagnetic poles, suggesting that faults in the eastern Altay have not experienced a large degree of vertical axis rotation and cannot have rotated >7° in the past 5 m.y. The lack of rotation along the Har-Us-Nuur fault combined with a large amount of rotation in the northern Altay fits with a kinematic model for transpressional deformation in which faults in the Altay have rotated to an orientation that favours the development of flower structures and building of mountainous topography, while at the same time the range widens at the edges as strain is transferred to better oriented structures. Thus the Har-Us-Nuur fault is a relatively young fault in the Altay, and has not yet accommodated significant rotation.

Preliminary confirmation of a surface faulting based on geological and earthquake data in the Puspiptek Serpong area

International Nuclear Information System (INIS)

Hadi Suntoko; Supartoyo

2016-01-01

BAPETEN regulation No. 8/2013 present the requirement that the site of the nuclear industry should not be a fault capable in a radius of 5 km. It is known that the RDE site composed of sandstones, clay stone, conglomerates and pumice rework the age of Pliocene, there straightness river valley hypothesized as a fault. Potential faults are identified using morphological observation, remote sensing using DEM rock outcrops, and seismic interpretation results that aims to confirm capable faults in a radius of 5 km. Traces defence surface is focused on the observation of the appearance of the terrain (land form), in the form of straightness morphology or valleys, fault scarp (fault scarp), shift or offset (river or hill), depression formed along fault zones, saddle, pressure ridge, and the shape of the river as well as earthquake monitoring. The results showed that there was no fault capable also a surface faulting that prove the presence in the RDE site radius of 5 km. (author)

Geomorphology, denudation rates, and stream channel profiles reveal patterns of mountain building adjacent to the San Andreas fault in northern California, USA

Science.gov (United States)

DeLong, Stephen B.; Hilley, George E.; Prentice, Carol S.; Crosby, Christopher J.; Yokelson, Intan N.

2017-01-01

Relative horizontal motion along strike-slip faults can build mountains when motion is oblique to the trend of the strike-slip boundary. The resulting contraction and uplift pose off-fault seismic hazards, which are often difficult to detect because of the poor vertical resolution of satellite geodesy and difficulty of locating offset datable landforms in active mountain ranges. Sparse geomorphic markers, topographic analyses, and measurement of denudation allow us to map spatiotemporal patterns of uplift along the northern San Andreas fault. Between Jenner and Mendocino, California, emergent marine terraces found southwest of the San Andreas fault record late Pleistocene uplift rates between 0.20 and 0.45 mm yr–1 along much of the coast. However, on the northeast side of the San Andreas fault, a zone of rapid uplift (0.6–1.0 mm yr–1) exists adjacent to the San Andreas fault, but rates decay northeastward as the coast becomes more distant from the San Andreas fault. A newly dated 4.5 Ma shallow-marine deposit located at ∼500 m above sea level (masl) adjacent to the San Andreas fault is warped down to just 150 masl 15 km northeast of the San Andreas fault, and it is exposed at just 60–110 masl to the west of the fault. Landscape denudation rates calculated from abundance of cosmogenic radionuclides in fluvial sediment northeast of, and adjacent to, the San Andreas fault are 0.16–0.29 mm yr–1, but they are only 0.03–0.07 mm yr–1 west of the fault. Basin-average channel steepness and the denudation rates can be used to infer the erosive properties of the underlying bedrock. Calibrated erosion rates can then be estimated across the entire landscape using the spatial distribution of channel steepness with these erosive properties. The lower-elevation areas of this landscape that show high channel steepness (and hence calibrated erosion rate) are distinct from higher-elevation areas with systematically lower channel steepness and denudation rates

Natural Preconditioning and Iterative Methods for Saddle Point Systems

KAUST Repository

Pestana, Jennifer

2015-01-01

© 2015 Society for Industrial and Applied Mathematics. The solution of quadratic or locally quadratic extremum problems subject to linear(ized) constraints gives rise to linear systems in saddle point form. This is true whether in the continuous or the discrete setting, so saddle point systems arising from the discretization of partial differential equation problems, such as those describing electromagnetic problems or incompressible flow, lead to equations with this structure, as do, for example, interior point methods and the sequential quadratic programming approach to nonlinear optimization. This survey concerns iterative solution methods for these problems and, in particular, shows how the problem formulation leads to natural preconditioners which guarantee a fast rate of convergence of the relevant iterative methods. These preconditioners are related to the original extremum problem and their effectiveness - in terms of rapidity of convergence - is established here via a proof of general bounds on the eigenvalues of the preconditioned saddle point matrix on which iteration convergence depends.

Paleoseismology of the Southern Section of the Black Mountains and Southern Death Valley Fault Zones, Death Valley, United States

Science.gov (United States)

Sohn, Marsha S.; Knott, Jeffrey R.; Mahan, Shannon

2014-01-01

The Death Valley Fault System (DVFS) is part of the southern Walker Lane–eastern California shear zone. The normal Black Mountains Fault Zone (BMFZ) and the right-lateral Southern Death Valley Fault Zone (SDVFZ) are two components of the DVFS. Estimates of late Pleistocene-Holocene slip rates and recurrence intervals for these two fault zones are uncertain owing to poor relative age control. The BMFZ southernmost section (Section 1W) steps basinward and preserves multiple scarps in the Quaternary alluvial fans. We present optically stimulated luminescence (OSL) dates ranging from 27 to 4 ka of fluvial and eolian sand lenses interbedded with alluvial-fan deposits offset by the BMFZ. By cross-cutting relations, we infer that there were three separate ground-rupturing earthquakes on BMFZ Section 1W with vertical displacement between 5.5 m and 2.75 m. The slip-rate estimate is ∼0.2 to 1.8 mm/yr, with an earthquake recurrence interval of 4,500 to 2,000 years. Slip-per-event measurements indicate Mw 7.0 to 7.2 earthquakes. The 27–4-ka OSL-dated alluvial fans also overlie the putative Cinder Hill tephra layer. Cinder Hill is offset ∼213 m by SDVFZ, which yields a tentative slip rate of 1 to 8 mm/yr for the SDVFZ.

Basic kinematics of the saddle and rider in high-level dressage horses trotting on a treadmill.

Science.gov (United States)

Byström, A; Rhodin, M; von Peinen, K; Weishaupt, M A; Roepstorff, L

2009-03-01

A comprehensive kinematic description of rider and saddle movements is not yet present in the scientific literature. To describe saddle and rider movements in a group of high-level dressage horses and riders. Seven high-level dressage horses and riders were subjected to kinematic measurements while performing collected trot on a treadmill. For analysis a rigid body model for the saddle and core rider segments, projection angles of the rider's extremities and the neck and trunk of the horse, and distances between markers selected to indicate rider position were used. For a majority of the variables measured it was possible to describe a common pattern for the group. Rotations around the transverse axis (pitch) were generally biphasic for each diagonal. During the first half of stance the saddle rotated anti-clockwise and the rider's pelvis clockwise viewed from the right and the rider's lumbar back extended. During the later part of stance and the suspension phase reverse pitch rotations were observed. Rotations of the saddle and core rider segments around the longitudinal (roll) and vertical axes (yaw) changed direction only around time of contact of each diagonal. The saddles and riders of high-level dressage horses follow a common movement pattern at collected trot. The movements of the saddle and rider are clearly related to the movements of the horse and saddle movements also seem to be influenced by the rider. Knowledge about rider and saddle movements can further our understanding of, and hence possibilities to prevent, orthopaedic injuries related to the exposure of the horse to a rider and saddle.

Perspective View, San Andreas Fault

Science.gov (United States)

2000-01-01

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

Late Quaternary slip history of the Mill Creek strand of the San Andreas fault in San Gorgonio Pass, southern California: The role of a subsidiary left-lateral fault in strand switching

Science.gov (United States)

Kendrick, Katherine J.; Matti, Jonathan; Mahan, Shannon

2015-01-01

The fault history of the Mill Creek strand of the San Andreas fault (SAF) in the San Gorgonio Pass region, along with the reconstructed geomorphology surrounding this fault strand, reveals the important role of the left-lateral Pinto Mountain fault in the regional fault strand switching. The Mill Creek strand has 7.1–8.7 km total slip. Following this displacement, the Pinto Mountain fault offset the Mill Creek strand 1–1.25 km, as SAF slip transferred to the San Bernardino, Banning, and Garnet Hill strands. An alluvial complex within the Mission Creek watershed can be linked to palinspastic reconstruction of drainage segments to constrain slip history of the Mill Creek strand. We investigated surface remnants through detailed geologic mapping, morphometric and stratigraphic analysis, geochronology, and pedogenic analysis. The degree of soil development constrains the duration of surface stability when correlated to other regional, independently dated pedons. This correlation indicates that the oldest surfaces are significantly older than 500 ka. Luminescence dates of 106 ka and 95 ka from (respectively) 5 and 4 m beneath a younger fan surface are consistent with age estimates based on soil-profile development. Offset of the Mill Creek strand by the Pinto Mountain fault suggests a short-term slip rate of ∼10–12.5 mm/yr for the Pinto Mountain fault, and a lower long-term slip rate. Uplift of the Yucaipa Ridge block during the period of Mill Creek strand activity is consistent with thermochronologic modeled uplift estimates.

Lithology, fault displacement, and origin of secondary calcium carbonate and opaline silica at Trenches 14 and 14D on the Bow Ridge Fault at Exile Hill, Nye County, Nevada

International Nuclear Information System (INIS)

Taylor, E.M.; Huckins, H.E.

1995-01-01

Yucca Mountain, a proposed site for a high-level nuclear-waste repository, is located in southern Nevada, 20 km east of Beatty, and adjacent to the southwest comer of the Nevada Test Site (NTS) (fig. 1). Yucca Mountain is located within the Basin and Range province of the western United States. The climate is semiarid, and the flora is transitional between that of the Mojave Desert to the south and the Great Basin Desert to the north. As part of the evaluation, hydrologic conditions, especially water levels, of Yucca Mountain and vicinity during the Quaternary, and especially the past 20,000 years, are being characterized. In 1982, the US Geological Survey, in cooperation with the US Department of Energy (under interagency agreement DE-A104-78ET44802), excavated twenty-six bulldozer and backhoe trenches in the Yucca Mountain region to evaluate the nature and frequency of Quaternary faulting (Swadley and others, 1984). The trenches were oriented perpendicular to traces of suspected Quaternary faults and across projections of known bedrock faults into Quaternary deposits. Trench 14 exposes the Bow Ridge Fault on the west side of Exile Hill. Although the original purpose of the excavation of trench 14 was to evaluate the nature and frequency of Quaternary faulting on the Bow Ridge Fault, concern arose as to whether or not the nearly vertical calcium carbonate (the term ''carbonate'' in this study refers to calcium carbonate) and opaline silica veins in the fault zone were deposited by ascending waters (ground water). These veins resemble in gross morphology veins commonly formed by hydrothermal processes

Incipient Evolution of the Eastern California Shear Zone through a Transpressional Zone along the San Andreas Fault in the San Bernardino Mountains, California

Science.gov (United States)

Cochran, W. J.; Spotila, J. A.

2017-12-01

Measuring long-term accumulation of strike-slip displacements and transpressional uplift is difficult where strain is accommodated across wide shear zones, as opposed to a single major fault. The Eastern California Shear Zone (ECSZ) in southern California accommodates dextral shear across several strike-slip faults, and is potentially migrating and cutting through a formerly convergent zone of the San Bernardino Mountains (SBM). The advection of crust along the San Andreas fault to the SE has forced these two tectonic regimes into creating a nexus of interacting strike-slip faults north of San Gorgonio Pass. These elements make this region ideal for studying complex fault interactions, evolving fault geometries, and deformational overprinting within a wide shear zone. Using high-resolution topography and field mapping, this study aims to test whether diffuse, poorly formed strike-slip faults within the uplifted SBM block are nascent elements of the ECSZ. Topographic resolution of ≤ 1m was achieved using both lidar and UAV surveys along two Quaternary strike-slip faults, namely the Lake Peak fault and Lone Valley faults. Although the Lone Valley fault cuts across Quaternary alluvium, the geomorphic expression is obscured, and may be the result of slow slip rates. In contrast, the Lake Peak fault is located high elevations north of San Gorgonio Peak in the SBM, and displaces Quaternary glacial deposits. The deposition of large boulders along the escarpment also obscures the apparent magnitude of slip along the fault. Although determining fault offset is difficult, the Lake Peak fault does display evidence for minor right-lateral displacement, where the magnitude of slip would be consistent with individual faults within the ECSZ (i.e. ≤ 1 mm/yr). Compared to the preservation of displacement along strike-slip faults located within the Mojave Desert, the upland region of the SBM adds complexity for measuring fault offset. The distribution of strain across the entire

Strong paleoearthquakes along the Talas-Fergana Fault, Kyrgyzstan

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A.M. Korzhenkov

2014-02-01

Full Text Available The Talas-Fergana Fault, the largest strike-slip structure in Centred. Asia, forms an obliquely oriented boundary between the northeastern and southwestern parts of the Tianshan mountain belt. The fault underwent active right-lateral strike-slip during the Paleozoic, with right-lateral movements being rejuvenated in the Late Cenozoic. Tectonic movements along the intracontinental strike-slip faults contribute to absorb part of the regional crustal shortening linked to the India-Eurasia collision; knowledge of strike-slip motions along the Talas-Fergana Fault are necessary for a complete assessment of the active deformation of the Tianshan orogen. To improve our understanding of the intracontinental deformation of the Tianshan mountain belt and the occurrence of strong earthquakes along the whole length of the Talas-Fergana Fault, we identify features of relief arising during strong paleoearthquakes along the Talas-Fergana Fault, fault segmentation, the length of seismogenic ruptures, and the energy and age of ancient catastrophes. We show that during neotectonic time the fault developed as a dextral strike-slip fault, with possible dextral displacements spreading to secondary fault planes north of the main fault trace. We determine rates of Holocene and Late Pleistocene dextral movements, and our radiocarbon dating indicates tens of strong earthquakes occurring along the fault zone during arid interval of 15800 years. The reoccurrence of strong earthquakes along the Talas-Fergana Fault zone during the second half of the Holocene is about 300 years. The next strong earthquake along the fault will most probably occur along its southeastern chain during the next several decades. Seismotectonic deformation parameters indicate that M > 7 earthquakes with oscillation intensity I > IX have occurred.

Rapid middle Miocene extension and unroofing of the southern Ruby Mountains, Nevada

Science.gov (United States)

Colgan, Joseph P.; Howard, Keith A.; Fleck, Robert J.; Wooden, Joseph L.

2010-01-01

Paleozoic rocks in the northern Ruby Mountains were metamorphosed during Mesozoic crustal shortening and Cenozoic magmatism, but equivalent strata in the southern Ruby Mountains were never buried deeper than stratigraphic depths prior to exhumation in the footwall of a west dipping brittle normal fault. In the southern Ruby Mountains, Miocene sedimentary rocks in the hanging wall of this fault date from 15.2 to 11.6 Ma and contain abundant detritus from the Paleozoic section. Apatite fission track and (U-Th)/He samples of the Eocene Harrison Pass pluton record rapid cooling that peaked ca. 17–15 Ma, while apatite fission track data from Jurassic plutons east and west of the southern Ruby Mountains indicate near-surface temperatures (pluton to be partially reset rather than to directly record fault slip. Our new data, together with published data on the distribution and composition of Miocene basin fill, suggest that rapid middle Miocene slip took place on the west dipping brittle detachment that bounds the Ruby Mountains and East Humboldt Range for 150 km along strike. This fault was thus active during a period of rapid extension (ca. 17–15 to 12–10 Ma) documented widely across the northern Basin and Range Province.

The Antitriangular Factorization of Saddle Point Matrices

KAUST Repository

Pestana, J.; Wathen, A. J.

2014-01-01

Mastronardi and Van Dooren [SIAM J. Matrix Anal. Appl., 34 (2013), pp. 173-196] recently introduced the block antitriangular ("Batman") decomposition for symmetric indefinite matrices. Here we show the simplification of this factorization for saddle

Codimension n saddle-nodes

International Nuclear Information System (INIS)

Gheiner, Jaques

2014-01-01

We consider the generic unfolding of a diffeomorphism on a compact C ∞ manifold that is Morse–Smale except for one non-hyperbolic periodic orbit being a codimension n saddle-node (one eigenvalue is 1, the other eigenvalues have norm different from 1). Local and global bifurcations are described. We characterize structural stability of the unfolding, depending on the codimension. A universal model of the unfolding is given when there is stability. Dynamical behaviour is analysed in other cases. (paper)

Uplifting model of the Longmenshan mountain in the eastern margin of Tibetan plateau

Science.gov (United States)

Zhang, S.; Ding, R.; Mao, C.

2010-12-01

Longmenshan mountain is a vivid manifestation of the Cenozoic orogenesis in the eastern margin of the Tibetan plateau, and a key to understand the geodynamics of eastward extending of the plateau. Thus the uplift mechanism of Longmenshan mountain became a hot spot issue of geosciences about the Tibetan plateau. Two entirely different hypotheses, i.e., crustal shortening and lower crustal channel flow, were put forward, but the solution is open. Further discussion need our deeper understanding about the uplifting features of the Longmenshan mountain. Fortunately, the uplifting processes were recorded objectively by peneplains and river landforms. We first analysed the peneplains and pediplanes of Longmenshan mountain and its surrounding areas, and surveyed the terraces of Dadu river running across the mountain. Then we studied the uplifting features of the study areas in late Cenozoic time on the basis of landform geometries. Finaly we discussed the possible mechanisms for the uplifting. There are two levels of peneplains whose peneplanations may begin in early Cenozoic time and end at late Miocene when the final fluctuations of elevations were possibly less than one kilometers. The valley of Dadu river is incised into the peneplains and has a staircase of no less than ten levels of terraces. The highest terrace is a strath which was contemporary with the pediplane in the piedmont formed in late Pliocene or in early Pleistocene. Due to their originally flat features, the peneplains and the strath terraces were used as datum planes for judging neotectonic deformations. Since late Miocene, the southeastern side of Longmenshan mountain has been dominated by thrust-faulting with a total vertical displacement of about 4500 m against the Sichuan basin, meantime the northwest side has been maintained flexural uplift with syncline hinge approximately following the Longriba fault. As a landform barrier between Tibetan plateau and Sichuan basin, the crest lines of the

Reliability Analysis of Operation for Cableways by FTA (Fault Tree Analysis Method

Directory of Open Access Journals (Sweden)

Sergej Težak

2010-05-01

Full Text Available This paper examines the reliability of the operation of cableway systems in Slovenia, which has major impact on the quality of service in the mountain tourism, mainly in wintertime. Different types of cableway installations in Slovenia were captured in a sample and fault tree analysis (FTA was made on the basis of the obtained data. The paper presents the results of the analysis. With these results it is possible to determine the probability of faults of different types of cableways, which types of faults have the greatest impact on the termination of operation, which components of cableways fail most, what is the impact of age of cableways on the occurrence of the faults. Finally, an attempt was made to find if occurrence of faults on individual cableway installation has also impact on traffic on this cableway due to reduced quality of service. KEYWORDS: cableways, aerial ropeways, chairlifts, ski-tows, quality, faults, fault tree analysis, reliability, service quality, winter tourism, mountain tourist centre

Reconstruction of chaotic saddles by classification of unstable periodic orbits: Kuramoto-Sivashinsky equation

Energy Technology Data Exchange (ETDEWEB)

Saiki, Yoshitaka, E-mail: yoshi.saiki@r.hit-u.ac.jp [Graduate School of Commerce and Management, Hitotsubashi University, Tokyo 186-8601 (Japan); Yamada, Michio [Research Institute for Mathematical Sciences (RIMS), Kyoto University, Kyoto 606-8502 (Japan); Chian, Abraham C.-L. [Paris Observatory, LESIA, CNRS, 92195 Meudon (France); National Institute for Space Research (INPE), P.O. Box 515, São José dos Campos, São Paulo 12227-010 (Brazil); Institute of Aeronautical Technology (ITA) and World Institute for Space Environment Research (WISER), São José dos Campos, São Paulo 12228-900 (Brazil); School of Mathematical Sciences, University of Adelaide, Adelaide SA 5005 (Australia); Department of Biomedical Engineering, George Washington University, Washington, DC 20052 (United States); Miranda, Rodrigo A. [Faculty UnB-Gama, and Plasma Physics Laboratory, Institute of Physics, University of Brasília (UnB), Brasília DF 70910-900 (Brazil); Rempel, Erico L. [Institute of Aeronautical Technology (ITA) and World Institute for Space Environment Research (WISER), São José dos Campos, São Paulo 12228-900 (Brazil)

2015-10-15

The unstable periodic orbits (UPOs) embedded in a chaotic attractor after an attractor merging crisis (MC) are classified into three subsets, and employed to reconstruct chaotic saddles in the Kuramoto-Sivashinsky equation. It is shown that in the post-MC regime, the two chaotic saddles evolved from the two coexisting chaotic attractors before crisis can be reconstructed from the UPOs embedded in the pre-MC chaotic attractors. The reconstruction also involves the detection of the mediating UPO responsible for the crisis, and the UPOs created after crisis that fill the gap regions of the chaotic saddles. We show that the gap UPOs originate from saddle-node, period-doubling, and pitchfork bifurcations inside the periodic windows in the post-MC chaotic region of the bifurcation diagram. The chaotic attractor in the post-MC regime is found to be the closure of gap UPOs.

Reconstruction of chaotic saddles by classification of unstable periodic orbits: Kuramoto-Sivashinsky equation

International Nuclear Information System (INIS)

Saiki, Yoshitaka; Yamada, Michio; Chian, Abraham C.-L.; Miranda, Rodrigo A.; Rempel, Erico L.

2015-01-01

The unstable periodic orbits (UPOs) embedded in a chaotic attractor after an attractor merging crisis (MC) are classified into three subsets, and employed to reconstruct chaotic saddles in the Kuramoto-Sivashinsky equation. It is shown that in the post-MC regime, the two chaotic saddles evolved from the two coexisting chaotic attractors before crisis can be reconstructed from the UPOs embedded in the pre-MC chaotic attractors. The reconstruction also involves the detection of the mediating UPO responsible for the crisis, and the UPOs created after crisis that fill the gap regions of the chaotic saddles. We show that the gap UPOs originate from saddle-node, period-doubling, and pitchfork bifurcations inside the periodic windows in the post-MC chaotic region of the bifurcation diagram. The chaotic attractor in the post-MC regime is found to be the closure of gap UPOs

The Evolution from Late Miocene West Salton Detachment Faulting to Cross-Cutting Pleistocene Oblique Strike-Slip Faults in the SW Salton Trough, Southern California

OpenAIRE

Steely, Alexander N.

2006-01-01

Field studies in the southwest Salton Trough between Yaqui Ridge and Borrego Mountain show that the West Salton detachment fault was active during the Pliocene and may have initiated during the latest Miocene. At Yaqui Ridge dominantly east-directed extension is recorded by slickenlines on the NW-striking detachment fault, and shows that the fault is actually a low-angle dextral oblique strike-slip fault. Crustal inheritance is responsible for the position of the fault at Yaqui Ridge, which r...

Late oligocene and miocene faulting and sedimentation, and evolution of the southern Rio Grande rift, New Mexico, USA

Science.gov (United States)

Mack, Greg H.; Seager, William R.; Kieling, John

1994-08-01

The distribution of nonmarine lithofacies, paleocurrents, and provenance data are used to define the evolution of late Oligocene and Miocene basins and complementary uplifts in the southern Rio Grande rift in the vicinity of Hatch, New Mexico, USA. The late Oligocene-middle Miocene Hayner Ranch Formation, which consists of a maximum of 1000 m of alluvial-fan, alluvial-flat, and lacustrine-carbonate lithofacies, was deposited in a narrow (12 km), northwest-trending, northeast-tilted half graben, whose footwall was the Caballo Mountains block. Stratigraphic separation on the border faults of the Caballo Mountains block was approximately 1615 m. An additional 854 m of stratigraphic separation along the Caballo Mountains border faults occurred during deposition of the middle-late Miocene Rincon Valley Formation, which is composed of up to 610 m of alluvial-fan, alluvial-flat, braided-fluvial, and gypsiferous playa lithofacies. Two new, north-trending fault blocks (Sierra de las Uvas and Dona Ana Mountains) and complementary west-northwest-tilted half graben also developed during Rincon Valley time, with approximately 549 m of stratigraphic separation along the border fault of the Sierra de las Uvas block. In latest Miocene and early Pliocene time, following deposition of the Rincon Valley Formation, movement continued along the border faults of the Caballo Mountains, Dona Ana Mountains, and Sierra de las Uvas blocks, and large parts of the Hayner Ranch and Rincon Valley basins were segmented into smaller fault blocks and basins by movement along new, largely north-trending faults. Analysis of the Hayner Ranch and Rincon Valley Formations, along with previous studies of the early Oligocene Bell Top Formation and late Pliocene-early Pleistocene Camp Rice Formation, indicate that the traditional two-stage model for development of the southern Rio Grande rift should be abandoned in favor of at least four episodes of block faulting beginning 35 Ma ago. With the exception of

Distribution of mountain wetlands and their response to Holocene climate change in the Hachimantai Volcanic Groups, northeastern Japan

Science.gov (United States)

Sasaki, N.; Sugai, T.

2017-12-01

Mountain wetlands, natural peatlands or lakes, with narrow catchment areas need abundant water supply and topography retaining water because of unstable water condition. This study examines wetland distribution with a focus on topography and snow accumulation, and discuss wetland evolution responding to Holocene climate change in the Hachimantai Volcanic Group, northeastern Japan, where the East Asian winter monsoon brings heavier snow and where has many wetlands of varied origin: crater lakes and wetlands in nivation hollows on original volcanic surfaces, and wetlands in depressions formed by landslides. We identified and classified wetlands using aerial photographs and 5-m and 10-m digital elevation models. Wetlands on the original volcanic surfaces tend to be concentrated under the small scarps with much snow or on saddles of the mountain ridge where snowmelt from surrounding slopes maintains a moist environment. More lake type wetlands are formed in the saddle than in the snowdrifts. That may represent that the saddles can correct more recharge water and may be a more suitable topographic condition for wetland formation and endurance. On the contrary, wetlands on landslides lie at the foot of the scarps where spring water can be abundantly supplied, regardless of snow accumulation. We used lithological analysis, 14C dating, tephra age data, and carbon contents of wetland cores to compare the evolution of wetlands, one (the Oyachi wetland) within a huge landslide and three (the Appi Highland wetlands) outside of a landslide area. We suggest that the evolution of the wetland in the landslide is primarily influenced by landslide movements and stream dissection rather than climate change. In the Appi Highland wetlands, peatlands appeared much later and at the almost same time in the Medieval Warm Period. We suggest that the development of mountain wetlands outside of landslide areas is primarily related to climate changes. Responsiveness of mountain wetlands to

Characterization of Quaternary and suspected Quaternary faults, Amargosa area, Nevada and California

International Nuclear Information System (INIS)

Anderson, R.E.; Crone, A.J.; Machette, M.N.; Bradley, L.A.; Diehl, S.F.

1995-01-01

This report presents the results of geologic studies that help define the Quaternary history of selected faults in the region around Yucca Mountain, Nevada. These results are relevant to the seismic-design basis of a potential nuclear waste repository at Yucca Mountain. The relevancy is based, in part, on a need for additional geologic data that became apparent in ongoing studies by S. Pezzopane (written commun., 1995) that resulted in the identification of 51 relevant and potentially relevant (see appendix A for definitions) individual and compound faults and fault zones in the 100-km-radius region around the Yucca Mountain site. These structures were divided into local and regional categories by Pezzopane (1995); this report deals with selected regional structures. In this introduction, the authors outline the scope and strategy of the studies and the tectonic environment of the studied structures

Characterization of Quaternary and suspected Quaternary faults, Amargosa area, Nevada and California

Energy Technology Data Exchange (ETDEWEB)

Anderson, R.E.; Crone, A.J.; Machette, M.N.; Bradley, L.A.; Diehl, S.F.

1995-12-31

This report presents the results of geologic studies that help define the Quaternary history of selected faults in the region around Yucca Mountain, Nevada. These results are relevant to the seismic-design basis of a potential nuclear waste repository at Yucca Mountain. The relevancy is based, in part, on a need for additional geologic data that became apparent in ongoing studies by S. Pezzopane (written commun., 1995) that resulted in the identification of 51 relevant and potentially relevant (see appendix A for definitions) individual and compound faults and fault zones in the 100-km-radius region around the Yucca Mountain site. These structures were divided into local and regional categories by Pezzopane (1995); this report deals with selected regional structures. In this introduction, the authors outline the scope and strategy of the studies and the tectonic environment of the studied structures.

Preconditioners for regularized saddle point matrices

Czech Academy of Sciences Publication Activity Database

Axelsson, Owe

2011-01-01

Roč. 19, č. 2 (2011), s. 91-112 ISSN 1570-2820 Institutional research plan: CEZ:AV0Z30860518 Keywords : saddle point matrices * preconditioning * regularization * eigenvalue clustering Subject RIV: BA - General Mathematics Impact factor: 0.533, year: 2011 http://www.degruyter.com/view/j/jnma.2011.19.issue-2/jnum.2011.005/jnum.2011.005. xml

Collection and analysis of existing information on applicability of investigation methods for estimation of beginning age of faulting in present faulting pattern

International Nuclear Information System (INIS)

Doke, Ryosuke; Yasue, Ken-ichi; Tanikawa, Shin-ichi; Nakayasu, Akio; Niizato, Tadafumi; Tanaka, Takenobu; Aoki, Michinori; Sekiya, Ayako

2011-12-01

In the field of R and D programs of a geological disposal of high level radioactive waste, it is great importance to develop a set of investigation and analysis techniques for the assessment of long-term geosphere stability over a geological time, which means that any changes of geological environment will not significantly impact on the long-term safety of a geological disposal system. In Japanese archipelago, crustal movements are so active that uplift and subsidence are remarkable in recent several hundreds of thousands of years. Therefore, it is necessary to assess the long-term geosphere stability taking into account a topographic change caused by crustal movements. One of the factors for the topographic change is the movement of an active fault, which is a geological process to release a strain accumulated by plate motion. A beginning age of the faulting in the present faulting pattern suggests the beginning age of neotectonic activities around the active fault, and also provides basic information to identifying the stage of a geomorphic development of mountains. Therefore, the age of faulting in the present faulting pattern is important information to estimate a topographic change in the future on the mountain regions of Japan. In this study, existing information related to methods for the estimation of the beginning age of the faulting in the present faulting pattern on the active fault were collected and reviewed. A principle of method, noticing points and technical know-hows in the application of the methods, data uncertainty, and so on were extracted from the existing information. Based on these extracted information, task-flows indicating working process on the estimation of the beginning age for the faulting of the active fault were illustrated on each method. Additionally, the distribution map of the beginning age with accuracy of faulting in the present faulting pattern on the active fault was illustrated. (author)

Influence of girth strap placement and panel flocking material on the saddle pressure pattern during riding of horses.

Science.gov (United States)

Byström, A; Stalfelt, A; Egenvall, A; Von Peinen, K; Morgan, K; Roepstorff, L

2010-11-01

Saddle fit is well recognised as an important factor for the health and performance of riding horses. However, only few studies have addressed general effects of different saddle construction details within a group of horses. To assess the influence of girth strap placement, traditional vs. v-system, and panel flocking material, wool vs. synthetic foam, on the saddle pressure pattern during riding. Six horses were ridden by 3 riders in sitting and rising trot and sitting canter. Saddle pressure was measured with 3 different saddle variants: 1) wool flocked panels and traditional girthing (baseline); 2) wool flocked panels and v-system girthing; and 3) foam filled panels and traditional girthing. From the pressure data, a number of descriptive variables were extracted. These were analysed using ANCOVA models with horse, rider, saddle, seat (sitting/rising, trot only) and speed as independent variables. With foam filled panels stride maximum pressures under the hind part of the saddle increased by 7-12% and the area under the saddle with a stride mean pressure >11 kPa increased by 114 cm(2) in trot and 127 cm(2) in canter. With v-system girthing, the latter variable also increased, but only by 53 and 38 cm(2) in trot and canter, respectively. In addition, stride maximum pressures under the front part of the saddle tended to increase (≤ 9%). Both flocking material and girthing have a significant influence on the saddle pressure and should thus be considered in saddle fitting. Wool seems a better flocking material than foam of the type used in the current study. For girthing, traditional placement seems equally good if not better than the v-system. However, further studies are needed to show if these results are valid for a larger population of riding horses. © 2010 EVJ Ltd.

DETECTING ALIEN LIMIT CYCLES NEAR A HAMILTONIAN 2-SADDLE CYCLE

OpenAIRE

LUCA, Stijn; DUMORTIER, Freddy; Caubergh, M.; Roussarie, R.

2009-01-01

This paper aims at providing and example of a cubic Hamiltonian 2-saddle cycle that after bifurcation can give rise to an alien limit cycle; this is a limit cycle that is not controlled by a zero of the related Abelian integral. To guarantee the existence of an alien limit cycle one can verify generic conditions on the Abelian integral and on the transition map associated to the connections of the 2-saddle cycle. In this paper, a general method is developed to compute the first and second der...

Quaternary faulting in the Tatra Mountains, evidence from cave morphology and fault-slip analysis

OpenAIRE

Szczygieł Jacek

2015-01-01

Tectonically deformed cave passages in the Tatra Mts (Central Western Carpathians) indicate some fault activity during the Quaternary. Displacements occur in the youngest passages of the caves indicating (based on previous U-series dating of speleothems) an Eemian or younger age for those faults, and so one tectonic stage. On the basis of stress analysis and geomorphological observations, two different mechanisms are proposed as responsible for the development of these displacements. The firs...

Late Cenozoic tephrochronology, stratigraphy, geomorphology, and neotectonics of the Western Black Mountains Piedmont, Death Valley, California: Implications for the spatial and temporal evolution of the Death Valley fault zone

Science.gov (United States)

Knott, Jeffrey Rayburn

This study presents the first detailed tephrochronologic study of the central Death Valley area by correlation of a Nomlaki-like tuff (>3.35 Ma), tuffs of the Mesquite Spring family (3.1 -- 3.35 Ma), a tuff of the lower Glass Mountain family (1.86 -- 2.06 Ma), and tephra layers from the upper Glass Mountain family (0.8 -- 1.2 Ma), the Bishop ash bed (0.76 Ma), the Lava Creek B ash bed (~0.66 Ma), and the Dibekulewe ash bed (~0.51 Ma). Correlation of these tuffs and tephra layers provides the first reliable numeric-age stratigraphy for late Cenozoic alluvial fan and lacustrine deposits for Death Valley and resulted in the naming of the informal early to middle Pleistocene Mormon Ploint formation. Using the numeric-age stratigraphy, the Death Valley fault zone (DVFZ) is interpreted to have progressively stepped basinward since the late Pliocene at Mormon Point and Copper Canyon. The Mormon Point turtleback or low-angle normal fault is shown to have unequivocal late Quaternary slip at its present low angle dip. Tectonic geomorphic analysis indicates that the (DVFZ) is composed of five geomorphic segments with the most persistent segment boundaries being the en-echelon step at Mormon Point and the bedrock salient at Artists Drive. Subsequent geomorphic studies resulting from the numeric-age stratigraphy and structural relations include application of Gilberts field criteria to the benches at Mormon Point indicating that the upper bench is a lacustrine strandline and the remaining topographically-lower benches are fault scarps across the 160--185 ka lake abrasion platform. In addition, the first known application of cosmogenic 10Be and 26Al exposure dating to a rock avalanche complex south of Badwater yielded an age of 29.5 +/- 1.9 ka for the younger avalanche. The 28 meter offset of the older avalanche may be interpreted as post-160--185 ka yielding a 0.1 mm/year slip rate, or post-29.5 +/- 1.9 ka yielding a maximum slip rate of 0.9 nun/year for the DVFZ. A consequence

Regional fault deformation characteristics before and after the Menyuan Ms6.4 earthquake

Directory of Open Access Journals (Sweden)

Ning Li

2016-07-01

Full Text Available This study analyzes data regarding cross-fault deformations within the seismogenic zone of the 2016 Qinghai Menyuan Ms6.4 earthquake and its surrounding area. The results showed that the tendency anomaly sites near the epicenter had relatively long anomaly durations prior to the earthquake, while sudden-jumping anomaly sites started to increase in the middle eastern Qilian Mountains approximately a year before the earthquake and continued to increase and migrate towards the vicinity of the epicenter two to six months before the earthquake. Intensive observations a few days after the earthquake indicated that abnormal returns and turns before the earthquake were significant, but all had small amplitudes, and the coseismic effect was generally minor. In addition, the post-seismic tendency analysis of individual cross faults in the Qilian Mountain fault zone revealed an accelerating thrust tendency at all cross-fault sites in the middle Qilian Mountains after the 2008 Wenchuan Ms8.0 earthquake. This indicates that the Wenchuan mega-earthquake exerted a great impact on the dynamic environment of the northeastern margin of the Qinghai-Tibet plate and significantly enhanced the extrusion effect of the Indian plate on the middle Qilian Mountains, generating favorable conditions for the occurrence of Menyuan thrust earthquakes.

Ground magnetic studies along a regional seismic-reflection profile across Bare Mountain, Crater Flat and Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Langenheim, V.E.; Ponce, D.A.

1995-01-01

Ground magnetic data were collected along a 26-km-long regional seismic-reflection profile in southwest Nevada that starts in the Amargosa Desert, crosses Bare Mountain, Crater Flat and Yucca Mountain, and ends in Midway Valley. Parallel ground magnetic profiles were also collected about 100 m to either side of the western half of the seismic-reflection line. The magnetic data indicate that the eastern half of Crater Flat is characterized by closely-spaced faulting (1--2 km) in contrast to the western half of Crater Flat. Modeling of the data indicates that the Topopah Spring Tuff is offset about 250 m on the Solitario Canyon fault and about 50 m on the Ghost Dance fault. These estimates of fault offset are consistent with seismic-reflection data and geologic mapping. A broad magnetic high of about 500--600 nT is centered over Crater Flat. Modeling of the magnetic data indicates that the source of this high is not thickening and doming of the Bullfrog Tuff, but more likely lies below the Bullfrog Tuff. Possible source lithologies for this magnetic high include altered argillite of the Eleana Formation, Cretaceous or Tertiary intrusions, and mafic sills

Aerial photographic interpretation of lineaments and faults in late Cenozoic deposits in the eastern parts of the Saline Valley 1:100, 000 quadrangle, Nevada and California, and the Darwin Hills 1:100, 000 quadrangle, California

International Nuclear Information System (INIS)

Reheis, M.C.

1991-01-01

Faults and fault-related lineaments in Quaternary and late Tertiary deposits in the southern part of the Walker Lane are potentially active and form patterns that are anomalous compared to those in most other areas of the Great Basin. Two maps at a scale of 1:100,000 summarize information about lineaments and faults in the area around and southwest of the Death Valley-Furnace Creek fault system based on extensive aerial-photo interpretation, limited field interpretation, limited field investigations, and published geologic maps. There are three major fault zones and two principal faults in the Saline Valley and Darwin Hills 1:100,000 quadrangles. (1) The Death Valley-Furnace Creek fault system and (2) the Hunter Mountain fault zone are northwest-trending right-lateral strike-slip fault zones. (3) The Panamint Valley fault zone and associated Towne Pass and Emigrant faults are north-trending normal faults. The intersection of the Hunter Mountain and Panamint Valley fault zones is marked by a large complex of faults and lineaments on the floor of Panamint Valley. Additional major faults include (4) the north-northwest-trending Ash Hill fault on the west side of Panamint Valley, and (5) the north-trending range-front Tin Mountain fault on the west side of the northern Cottonwood Mountains. The most active faults at present include those along the Death Valley-Furnace Creek fault system, the Tin Mountain fault, the northwest and southeast ends of the Hunter Mountain fault zone, the Ash Hill fault, and the fault bounding the west side of the Panamint Range south of Hall Canyon. Several large Quaternary landslides on the west sides of the Cottonwood Mountains and the Panamint Range apparently reflect slope instability due chiefly to rapid uplift of these ranges. 16 refs

Parametric CAD and Fea Model of a Saddle Tapping Tee

DEFF Research Database (Denmark)

A. Kristensen, Anders Schmidt; Lund Jepsen, Kristian

2007-01-01

 Often it is necessary to branch of a pipe section on an oilrig. This operation is often performed by making a so-called "Hot Tapping", which involves welding a pipe and a flange on to the pipe section. A spherical valve and a gate are mounted on to the flange, i.e. weld-o-let. In order to perform...... the welding operations a so-called habitat must be constructed. This habitat encapsulates the "Hot Tapping" spot and is relatively costly. Thus, to avoid weld operations on to the pipeline, a solution with clamps has been developed, i.e. a Saddle Tapping Tee. The Saddle Tapping Tee is clamped on the pipe...... is determined from paragraph K302.3.2 in ASME B31.3. A full parametric 3D CAD model of the Saddle Tapping Tee is developed where a number of user-defined parameters are controlled from an Excel spreadsheet allowing parameter studies and technical documentation to be generated effectively. The same Excel spread...

Geologic map of the Ute Mountain 7.5' quadrangle, Taos County, New Mexico, and Conejos and Costilla Counties, Colorado

Science.gov (United States)

Thompson, Ren A.; Turner, Kenzie J.; Shroba, Ralph R.; Cosca, Michael A.; Ruleman, Chester A.; Lee, John P.; Brandt, Theodore R.

2014-01-01

The Ute Mountain 7.5' quadrangle is located in the south-central part of the San Luis Basin of northern New Mexico, in the Rio Grande del Norte National Monument, and contains deposits that record volcanic, tectonic, and associated alluvial and colluvial processes over the past four million years. Ute Mountain has the distinction of being one of the largest intermediate composition eruptive centers of the Taos Plateau, a largely volcanic tableland occupying the southern portion of the San Luis Basin. Ute Mountain rises to an elevation in excess of 3,000 m, nearly 700 m above the basaltic plateau at its base, and is characterized by three distinct phases of Pliocene eruptive activity recorded in the stratigraphy exposed on the flanks of the mountain and in the Rio Grande gorge. Unconformably overlain by largely flat-lying lava flows of Servilleta Basalt, the area surrounding Ute Mountain records a westward thickening of basin-fill volcanic deposits interstratified in the subsurface with Pliocene basin-fill sedimentary deposits derived from older Tertiary and Precambrian sources to the east. Superimposed on this volcanic stratigraphy are alluvial and colluvial deposits derived from the flanks of Ute Mountain and more distally-derived alluvium from the uplifted Sangre de Cristo Mountains to the east, that record a complex temporal and stratigraphic succession of Quaternary basin deposition and erosion. Pliocene and younger basin deposition was accommodated along predominantly north-trending fault-bounded grabens. These poorly exposed fault scarps cutting lava flows of Ute Mountain volcano. The Servilleta Basalt and younger surficial deposits record largely down-to-east basinward displacement. Faults are identified with varying confidence levels in the map area. Recognizing and mapping faults developed near the surface in young, brittle volcanic rocks is difficult because: (1) they tend to form fractured zones tens of meters wide rather than discrete fault planes, (2

Reconnaissance and economic geology of Copper Mountain metamorphic complex, Owl Creek Mountains, Wyoming

International Nuclear Information System (INIS)

Hausel, W.D.

1983-01-01

The Copper Mountain metamorphic complex lies within a westerly trending belt of Precambrian exposures known as the Owl Creek Mountains uplift. The metamorphic complex at Copper Mountain is part of a larger complex known as the Owl Creek Mountains greenstone belt. Until more detailed mapping and petrographic studies can be completed, the Copper Mountain area is best referred to as a complex, even though it has some characteristics of a greestone belt. At least three episodes of Precambrian deformation have affected the supracrustals, and two have disturbed the granites. The final Precambrian deformation event was preceded by a weak thermal event expressed by retrogressive metamorphism and restricted metasomatic alteration. During this event, a second phase of pegmatization was accompanied by hydrothermal solutions. During the Laramide orogeny, Copper Mountain was again modified by deformation. Laramide deformation produced complex gravity faults and keystone grabens. Uranium deposits were formed following major Laramide deformation. The genesis of these deposits is attributable to either the leaching of granites or the leaching of overlying tuffaceous sediments during the Tertiary. Production of metals and industrial minerals has been limited, although some gold, copper, silver, tungsten, beryl, feldspar, and lithium ore have been shipped from Copper Mountain. A large amount of uranium was produced from the Copper Mountain district in the 1950s

Active tectonics of the Binalud Mountains, a key puzzle segment to describe Quaternary deformations at the northeastern boundary of the Arabia-Eurasia collision

Science.gov (United States)

Shabanian, Esmaeil; Bellier, Olivier; Siame, Lionel L.; Abbassi, Mohammad R.; Leanni, Laetitia; Braucher, Régis; Farbod, Yassaman; Bourlès, Didier L.

2010-05-01

In northeast Iran, the Binalud Mountains accommodate part of active convergence between the Arabian and Eurasian plates. This fault-bounded mountain range has been considered a key region to describe Quaternary deformations at the northeastern boundary of the Arabia-Eurasia collision. But, the lack of knowledge on active faulting hampered evaluating the geological reliability of tectonic models describing the kinematics of deformation in northeast Iran. Morphotectonic investigations along both sides of the Binalud Mountains allowed us to characterize the structural and active faulting patterns along the Neyshabur and Mashhad fault systems on the southwest and northeast sides of the mountain range, respectively. We applied combined approaches of morphotectonic analyses based on satellite imageries (SPOT5 and Landsat ETM+), STRM and site-scale digital topographic data, and field surveys complemented with in situ-produced 10Be exposure dating to determine the kinematics and rate of active faulting. Three regional episodes of alluvial surface abandonments were dated at 5.3±1.1 kyr (Q1), 94±5 kyr (Q3), and 200±14 kyr (S3). The geomorphic reconstruction of both vertical and right-lateral fault offsets postdating these surface abandonment episodes yielded Quaternary fault slip rates on both sides of the Binalud Mountains. On the Neyshabur Fault System, thanks to geomorphic reconstructions of cumulative offsets recorded by Q3 fan surfaces, slip rates of 2.7±0.8 mm/yr and 2.4±0.2 mm/yr are estimated for right-lateral and reverse components of active faulting, respectively. Those indicate a total slip rate of 3.6±1.2 mm/yr for the late Quaternary deformation on the southwest flank of the Binalud Mountains. Reconstructing the cumulative right-lateral offset recorded by S3 surfaces, a middle-late Quaternary slip rate of 1.6±0.1 mm/yr is determined for the Mashhad Fault System. Altogether, our geomorphic observations reveal that, on both sides of the Binalud Mountains

GPR Imaging of Fault Related Folds in a Gold-Bearing Metasedimentary Sequence, Carolina Terrane, Southern Appalachian Mountains

Science.gov (United States)

Diemer, J. A.; Bobyarchick, A. R.

2015-12-01

The Carolina terrane comprises Ediacaran to earliest Paleozoic mixed magmatic and sedimentary assemblages in the central and eastern Piedmont of the Southern Appalachian Mountains. The terrane was primarily deformed during the Late Ordovician Cherokee orogeny, that reached greenschist facies metamorphism. The Albemarle arc, a younger component of the Carolina terrane, contains volcanogenic metasedimentary rocks with intercalated mainly rhyolitic volcanic rocks. Regional inclined to overturned folds with axial planar cleavage verge southeast. At mesoscopic scales (exposures of a few square meters), folds sympathetic with regional folds are attenuated or truncated by ductile shear zones or contractional faults. Shear and fault zones are most abundant near highly silicified strataform zones in metagraywacke of the Tillery Formation; these zones are also auriferous. GPR profiles were collected across strike of two silicified, gold-bearing zones and enclosing metagraywacke to characterize the scale and extent of folding in the vicinity of ore horizons. Several GSSI SIR-3000 / 100 MHz monostatic GPR profiles were collected in profiles up to 260 meters long. In pre-migration lines processed for time zero and background removal, several clusters of shallow, rolling sigmoidal reflectors appeared separated by sets of parallel, northwest-dipping reflective discontinuities. These features are inferred to be reverse faults carrying contractional folds. After migration with an average velocity of 0.105 m/ns, vertical heights of the inferred folds became attenuated but not removed, and contractional fault reflections remained prominent. After migration, a highly convex-up cluster of reflections initially assumed to be a fold culmination resolved to an elliptical patch of high amplitudes. The patch is likely an undisclosed shaft or covered trench left by earlier gold prospecting. In this survey, useful detail appeared to a depth of 7.5 meters, and only a few gently inclined

Magnitude and Surface Rupture Length of Prehistoric Upper Crustal Earthquakes in the Puget Lowland, Washington State

Science.gov (United States)

Sherrod, B. L.; Styron, R. H.

2016-12-01

Paleoseismic studies documented prehistoric earthquakes after the last glaciation ended 15 ka on 13 upper-crustal fault zones in the Cascadia fore arc. These fault zones are a consequence of north-directed fore arc block migration manifesting as a series of bedrock uplifts and intervening structural basins in the southern Salish Sea lowland between Vancouver, B.C. to the north and Olympia, WA to the south, and bounded on the east and west by the Cascade Mountains and Olympic Mountains, respectively. Our dataset uses published information and includes 27 earthquakes tabulated from observations of postglacial deformation at 63 sites. Stratigraphic offsets along faults consist of two types of measurements: 1) vertical separation of strata along faults observed in fault scarp excavations, and 2) estimates from coastal uplift and subsidence. We used probabilistic methods to estimate past rupture magnitudes and surface rupture length (SRL), applying empirical observations from modern earthquakes and point measurements from paleoseismic sites (Biasi and Weldon, 2006). Estimates of paleoearthquake magnitude ranged between M 6.5 and M 7.5. SRL estimates varied between 20 and 90 km. Paleoearthquakes on the Seattle fault zone and Saddle Mountain West fault about 1100 years ago were outliers in our analysis. Large offsets observed for these two earthquakes implies a M 7.8 and 200 km SRL, given the average observed ratio of slip/SRL in modern earthquakes. The actual mapped traces of these faults are less than 200km, implying these earthquakes had an unusually high static stress drop or, in the case of the Seattle fault, splay faults may have accentuated uplift in the hanging wall. Refined calculations incorporating fault area may change these magnitude and SRL estimates. Biasi, G.P., and Weldon, R.J., 2006, Estimating Surface Rupture Length and Magnitude of Paleoearthquakes from Point Measurements of Rupture Displacement: B. Seismol. Soc. Am., 96, 1612-1623.

Optimization of saddle coils for magnetic resonance imaging

International Nuclear Information System (INIS)

Salmon, Carlos Ernesto Garrido; Vidoto, Edson Luiz Gea; Martins, Mateus Jose; Tannus, Alberto

2006-01-01

In Nuclear Magnetic Resonance (NMR) experiments, besides the apparatus designed to acquire the NMR signal, it is necessary to generate a radio frequency electromagnetic field using a device capable to transduce electromagnetic power into a transverse magnetic field. We must generate this transverse homogeneous magnetic field inside the region of interest with minimum power consumption. Many configurations have been proposed for this task, from coils to resonators. For low field intensity (<0.5 T) and small sample dimensions (<30 cm), the saddle coil configuration has been widely used. In this work we present a simplified method for calculating the magnetic field distribution in these coils considering the current density profile. We propose an optimized saddle configuration as a function of the dimensions of the region of interest, taking into account the uniformity and the sensitivity. In order to evaluate the magnetic field uniformity three quantities have been analyzed: Non-uniformity, peak-to-peak homogeneity and relative uniformity. Some experimental results are presented to validate our calculation. (author)

Postobductional extension along and within the Frontal Range of the Eastern Oman Mountains

Science.gov (United States)

Mattern, Frank; Scharf, Andreas

2018-04-01

The Oman Mountains formed by late Cretaceous obduction of the Tethys-derived Semail Ophiolite. This study concerns the postobductional extension on the northern flank of the mountain belt. Nine sites at the northern margins of the Jabal Akhdar/Nakhl and Saih Hatat domes of the Eastern Oman ("Hajar") Mountains were investigated. The northern margins are marked by a system of major interconnected extensional faults, the "Frontal Range Fault". While the vertical displacements along the Saih Hatat and westerly located Jabal Nakhl domes measure 2.25-6.25 km, 0.5-4.5 km and 4-7 km, respectively, it amounts to 1-5 km along the Jabal Akhdar Dome. Extension had started during the late Cretaceous, towards the end of ophiolite emplacement. Two stages of extension can be ascertained (late Cretaceous to early Eocene and probably Oligocene) at the eastern part of the Frontal Range Fault System (Wadi Kabir and Fanja Graben faults of similar strike). Along the intervening and differently striking fault segments at Sad and Sunub the same two stages of deformation are deduced. The first stage is characterized again by extension. The second stage is marked by dextral motion, including local transtension. Probable Oligocene extension affected the Batinah Coast Fault while it also affected the Wadi Kabir Fault and the Fanja Graben. It is unclear whether the western portion of the Frontal Range Fault also went through two stages of deformation. Bedding-parallel ductile and brittle deformation is a common phenomenon. Hot springs and listwaenite are associated with dextral releasing bends within the fault system, as well as a basalt intrusion of probable Oligocene age. A structural transect through the Frontal Range along the superbly exposed Wadi Bani Kharous (Jabal Akhdar Dome) revealed that extension affected the Frontal Range at least 2.5 km south of the Frontal Range Fault. Also here, bedding-parallel shearing is important, but not exclusive. A late Cretaceous thrust was

Natural Preconditioning and Iterative Methods for Saddle Point Systems

KAUST Repository

Pestana, Jennifer; Wathen, Andrew J.

2015-01-01

or the discrete setting, so saddle point systems arising from the discretization of partial differential equation problems, such as those describing electromagnetic problems or incompressible flow, lead to equations with this structure, as do, for example

Geodesy and contemporary strain in the Yucca Mountain region, Nevada

International Nuclear Information System (INIS)

Keefer, W.R.; Coe, J.A.; Pezzopane, S.K.; Hunter, W.C.

1997-01-01

Geodetic surveys provide important information for estimating recent ground movement in support of seismotectonic investigations of the potential nuclear-waste storage site at Yucca Mountain, Nevada. Resurveys of established level lines document up to 22 millimeters of local subsidence related to the 1992 Little Skull Mountain earthquake, which is consistent with seismic data that show normal-slip rupture and with data from a regional trilateration network. Comparison of more recent surveys with a level line first established in 1907 suggests 3 to 13 centimeters of subsidence in the Crater Flat-Yucca Mountain structural depression that coincides with the Bare Mountain fault; small uplifts also were recorded near normal faults at Yucca Mountain. No significant deformation was recorded by a trilateration network over a 10-year period, except for coseismic deformation associated with the Little Skull Mountain earthquake, but meaningful results are limited by the short temporal period of that data set and the small rate of movement. Very long baseline interferometry that is capable of measuring direction and rates of deformation is likewise limited by a short history of observation, but rates of deformation between 8 and 13 millimeters per year across the basin and Range province are indicated by the available data

Tertiary volcanic rocks and uranium in the Thomas Range and northern Drum Mountains, Juab County, Utah

Science.gov (United States)

Lindsey, David A.

1982-01-01

The Thomas Range and northern Drum Mountains have a history of volcanism, faulting, and mineralization that began about 42 m.y. (million years) ago. Volcanic activity and mineralization in the area can be divided into three stages according to the time-related occurrence of rock types, trace-element associations, and chemical composition of mineral deposits. Compositions of volcanic rocks changed abruptly from rhyodacite-quartz latite (42-39 m.y. ago) to rhyolite (38-32 m.y. ago) to alkali rhyolite (21 and 6-7 m.y. ago); these stages correspond to periods of chalcophile and siderophile metal mineralization, no mineralization(?), and lithophile metal mineralization, respectively. Angular unconformities record episodes of cauldron collapse and block faulting between the stages of volcanic activity and mineralization. The youngest angular unconformity formed between 21 and 7 m.y. ago during basin-and-range faulting. Early rhyodacite-quartz latite volcanism from composite volcanoes and fissures produced flows, breccias, and ash-flow tuff of the Drum Mountains Rhyodacite and Mt. Laird Tuff. Eruption of the Mt. Laird Tuff about 39 m.y. ago from an area north of Joy townsite was accompanied by collapse of the Thomas caldera. Part of the roof of the magma chamber did not collapse, or the magma was resurgent, as is indicated by porphyry dikes and plugs in the Drum Mountains. Chalcophile and siderophile metal mineralization, resulting in deposits of copper, gold, and manganese, accompanied early volcanism. Te middle stage of volcanic activity was characterized by explosive eruption of rhyolitic ash-flow tuffs and collapse of the Dugway Valley cauldron. Eruption of the Joy Tuff 38 m.y. ago was accompanied by subsidence of this cauldron and was followed by collapse and sliding of Paleozoic rocks from the west wall of the cauldron. Landslides in The Dell were covered by the Dell Tuff, erupted 32 m.y. ago from an unknown source to the east. An ash flow of the Needles Range

Growth and erosion of mountain ranges at the northeastern margin of Tibet

Science.gov (United States)

Hetzel, Ralf; Palumbo, Luigi; Giese, Jörg; Guo, Jianming

2010-05-01

The hypothesis that mountain belts may reach a steady state, in which rock uplift is balanced by erosion, has been supported by numerous field studies and numerical models. The early evolution of mountain ranges, however, and especially the relation between fault growth and topographic response has received little attention. By using a space-for-time substitution we illustrate how active thrust faults and small, fault-bounded mountain ranges evolve into mature mountain chains that will ultimately be incorporated into the laterally growing Tibetan Plateau. At an early stage of development, when faults propagate laterally, slip rates are constant along strike [1-3]. As long as no significant topographic relief has developed, tectonic uplift is at least an order of magnitude faster than the rate of erosion [2,4]. During progressive relief growth and the establishment of drainage basins, erosion of the rising mountain ranges becomes more important, but the studied ranges are still in a pre-steady state and continue to grow both vertically and laterally [5]. During this stage the rate of erosion is linearly correlated to the mean hillslope gradient and the mean local relief, if differences in lithology or rock strength are negligible [6]. The rate of relief growth may be inferred from the difference between local erosion rates on ridge crests and catchment-wide denudation rates [7] - the latter may be taken as a surrogate for the rate of river incision. As hillslopes approach a threshold value, landsliding becomes the dominant process of mass transport and erosion rates increase non-linearly with slope. Once a steady state has been reached, the erosion rate is equal to the rate of rock uplift. A key problem is how the rate of rock uplift can be quantified in such regions, because the stochastic distribution of landslides causes the denudation rates inferred from 10Be in river sediment to be highly variable [8]. References [1] Hetzel et al. (2004). Implications of the

Fluid flow and permeabilities in basement fault zones

Science.gov (United States)

Hollinsworth, Allan; Koehn, Daniel

2017-04-01

Fault zones are important sites for crustal fluid flow, specifically where they cross-cut low permeability host rocks such as granites and gneisses. Fluids migrating through fault zones can cause rheology changes, mineral precipitation and pore space closure, and may alter the physical and chemical properties of the host rock and deformation products. It is therefore essential to consider the evolution of permeability in fault zones at a range of pressure-temperature conditions to understand fluid migration throughout a fault's history, and how fluid-rock interaction modifies permeability and rheological characteristics. Field localities in the Rwenzori Mountains, western Uganda and the Outer Hebrides, north-west Scotland, have been selected for field work and sample collection. Here Archaean-age TTG gneisses have been faulted within the upper 15km of the crust and have experienced fluid ingress. The Rwenzori Mountains are an anomalously uplifted horst-block located in a transfer zone in the western rift of the East African Rift System. The north-western ridge is characterised by a tectonically simple western flank, where the partially mineralised Bwamba Fault has detached from the Congo craton. Mineralisation is associated with hydrothermal fluids heated by a thermal body beneath the Semliki rift, and has resulted in substantial iron oxide precipitation within porous cataclasites. Non-mineralised faults further north contain foliated gouges and show evidence of leaking fluids. These faults serve as an analogue for faults associated with the Lake Albert oil and gas prospects. The Outer Hebrides Fault Zone (OHFZ) was largely active during the Caledonian Orogeny (ca. 430-400 Ma) at a deeper crustal level than the Ugandan rift faults. Initial dry conditions were followed by fluid ingress during deformation that controlled its rheological behaviour. The transition also altered the existing permeability. The OHFZ is a natural laboratory in which to study brittle fault

Generalized saddle point condition for ignition in a tokamak reactor with temperature and density profiles

International Nuclear Information System (INIS)

Mitari, O.; Hirose, A.; Skarsgard, H.M.

1989-01-01

In this paper, the concept of a generalized ignition contour map, is extended to the realistic case of a plasma with temperature and density profiles in order to study access to ignition in a tokamak reactor. The generalized saddle point is found to lie between the Lawson and ignition conditions. If the height of the operation path with Goldston L-mode scaling is higher than the generalized saddle point, a reactor can reach ignition with this scaling for the case with no confinement degradation effect due to alpha-particle heating. In this sense, the saddle point given in a general form is a new criterion for reaching ignition. Peaking the profiles for the plasma temperature and density can lower the height of the generalized saddle point and help a reactor to reach ignition. With this in mind, the authors can judge whether next-generation tokamaks, such as Compact Ignition Tokamak, Tokamak Ignition/Burn Experimental Reactor, Next European Torus, Fusion Experimental Reactor, International Tokamak Reactor, and AC Tokamak Reactor, can reach ignition with realistic profile parameters and an L-mode scaling law

Stratigraphic and structural framework of Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Spengler, R.W.; Fox, K.F. Jr.

1988-01-01

Yucca Mountain is located within the southwestern Nevada volcanic field, ∼140 km northwest of Las Vegas, Nevada, and 50 km northeast of Death Valley, California. The mountain consist of a series of long, linear, north-trending volcanic ridges that approach an 1800-m maximum elevation near The Prow. The broad intermontane alluviated valleys of Crater Flat, the Amargosa Desert, and Jackass Flats, averaging 800 to 1100 m in elevation, form the western, southern, and eastern margins of Yucca Mountain, respectively. North of The Prow, Yucca Mountain merges with other volcanic highlands that flank the southern rim of the Timber Mountain-Oasis Valley caldera complex. The stratigraphy and structure of the area are discussed. Future geologic studies will attempt to determine if faults extend beneath Yucca Mountain, and, if present, their potential effects on the hydrologic and tectonic regimes

Preliminary mapping of surficial geology of Midway Valley Yucca Mountain Project, Nye County, Nevada

International Nuclear Information System (INIS)

Wesling, J.R.; Bullard, T.F.; Swan, F.H.; Perman, R.C.; Angell, M.M.; Gibson, J.D.

1992-04-01

The tectonics program for the proposed high-level nuclear waste repository at Yucca Mountain in southwestern Nevada must evaluate the potential for surface faulting beneath the prospective surface facilities. To help meet this goal, Quaternary surficial mapping studies and photolineament analyses were conducted to provide data for evaluating the location, recency, and style of faulting with Midway Valley at the eastern base of Yucca Mountain, the preferred location of these surface facilities. This interim report presents the preliminary results of this work

Transverse tectonic structural elements across Himalayan mountain front, eastern Arunachal Himalaya, India: Implication of superposed landform development on analysis of neotectonics

Science.gov (United States)

Bhakuni, S. S.; Luirei, Khayingshing; Kothyari, Girish Ch.; Imsong, Watinaro

2017-04-01

Structural and morphotectonic signatures in conjunction with the geomorphic indices are synthesised to trace the role of transverse tectonic features in shaping the landforms developed along the frontal part of the eastern Arunachal sub-Himalaya. Mountain front sinuosity (Smf) index values close to one are indicative of the active nature of the mountain front all along the eastern Arunachal Himalaya, which can be directly attributed to the regional uplift along the Himalayan Frontal Thrust (HFT). However, the mountain front is significantly sinusoidal around junctions between HFT/MBT (Main Boundary Thrust) and active transverse faults. The high values of stream length gradient (SL) and stream steepness (Ks) indices together with field evidence of fault scarps, offset of terraces, and deflection of streams are markers of neotectonic uplift along the thrusts and transverse faults. This reactivation of transverse faults has given rise to extensional basins leading to widening of the river courses, providing favourable sites for deposition of recent sediments. Tectonic interactions of these transverse faults with the Himalayan longitudinal thrusts (MBT/HFT) have segmented the mountain front marked with varying sinuosity. The net result is that a variety of tectonic landforms recognized along the mountain front can be tracked to the complex interactions among the transverse and longitudinal tectonic elements. Some distinctive examples are: in the eastern extremity of NE Himalaya across the Dibang River valley, the NW-SE trending mountain front is attenuated by the active Mishmi Thrust that has thrust the Mishmi crystalline complex directly over the alluvium of the Brahmaputra plains. The junction of the folded HFT and Mishmi Thrust shows a zone of brecciated and pulverized rocks along which transverse axial planar fracture cleavages exhibit neotectonic activities in a transverse fault zone coinciding with the Dibang River course. Similarly, the transverse faults cut the

Photomosaics and event evidence from the Frazier Mountain paleoseismic site, trench 1, cuts 5–24, San Andreas Fault Zone, southern California (2010–2012)

Science.gov (United States)

Scharer, Katherine M.; Fumal, Tom E.; Weldon, Ray J.; Streig, Ashley R.

2015-08-24

The Frazier Mountain paleoseismic site is located within the northern Big Bend of the southern San Andreas Fault (lat 34.8122° N., lon 118.9034° W.), in a small structural basin formed by the fault (fig. 1). The site has been the focus of over a decade of paleoseismic study due to high stratigraphic resolution and abundant dateable material. Trench 1 (T1) was initially excavated as a 50-m long, fault-perpendicular trench crossing the northern half of the basin (Lindvall and others, 2002; Scharer and others, 2014a). Owing to the importance of a high-resolution trench site at this location on a 200-km length of the fault with no other long paleoseismic records, later work progressively lengthened and deepened T1 in a series of excavations, or cuts, that enlarged the original excavation. Scharer and others (2014a) provide the photomosaics and event evidence for the first four cuts, which largely show the upper section of the site, represented by alluvial deposits that date from about A.D. 1500 to present. Scharer and others (2014b) discuss the earthquake evidence and dating at the site within the context of prehistoric rupture lengths and magnitudes on the southern San Andreas Fault. Here we present the photomosaics and event evidence for a series of cuts from the lower section, covering sediments that were deposited from about A.D. 500 to 1500 (fig. 2).

The effectiveness of adhesives on the retention of mandibular free end saddle partial dentures: An in vitro study.

Science.gov (United States)

Quiney, Daniel; Nishio Ayre, Wayne; Milward, Paul

2017-07-01

Existing in vitro methods for testing denture adhesives do not fully replicate the complex oral geometries and environment; and in vivo methods are qualitative, prone to bias and not easily reproducible. The purpose of this study was to develop a novel, quantitative and more accurate model to test the effect of adhesives on the retentive force of mandibular free end saddle partial dentures. An in vitro model was developed based on an anatomically accurate cast of a clinical case. Experimentally, the amount of adhesive was varied (0.2g-1g) and the tensile force required for displacement was measured. Different commercially available adhesives were then tested at the optimum volume using the in vitro model. A 3D finite element model of the denture was used to assess how the forces to induce denture displacement varied according to the position of the force along the saddle length. The mass of adhesive was found to significantly alter retention forces, with 0.4-0.7g being the optimum range for this particular scenario. Use of adhesives significantly improved mandibular free end saddle partial denture retention with the worst performing adhesive increasing retention nine-fold whilst the best performing adhesive increased retention twenty three-fold. The finite element model revealed that 77% more force was required to displace the denture by positioning forces towards the mesial end of the saddle compared to the distal end. An in vitro denture adhesive model was developed, which demonstrated that mass of adhesive plays a significant role in enhancing denture retention and supported the design principle of placing as few teeth as clinically necessary on the distal end of the free end saddles. Limiting the position of teeth on free end saddles to the mesial and mid portion of the saddle will reduce displacements caused by mastication. The movement of mandibular free end saddle partial dentures can be restricted with the use of denture adhesives. Altering the mass of

Rotating saddle trap as Foucault's pendulum

Science.gov (United States)

Kirillov, Oleg N.; Levi, Mark

2016-01-01

One of the many surprising results found in the mechanics of rotating systems is the stabilization of a particle in a rapidly rotating planar saddle potential. Besides the counterintuitive stabilization, an unexpected precessional motion is observed. In this note, we show that this precession is due to a Coriolis-like force caused by the rotation of the potential. To our knowledge, this is the first example where such a force arises in an inertial reference frame. We also propose a simple mechanical demonstration of this effect.

Complex saddle points and the sign problem in complex Langevin simulation

International Nuclear Information System (INIS)

Hayata, Tomoya; Hidaka, Yoshimasa; Tanizaki, Yuya

2016-01-01

We show that complex Langevin simulation converges to a wrong result within the semiclassical analysis, by relating it to the Lefschetz-thimble path integral, when the path-integral weight has different phases among dominant complex saddle points. Equilibrium solution of the complex Langevin equation forms local distributions around complex saddle points. Its ensemble average approximately becomes a direct sum of the average in each local distribution, where relative phases among them are dropped. We propose that by taking these phases into account through reweighting, we can solve the wrong convergence problem. However, this prescription may lead to a recurrence of the sign problem in the complex Langevin method for quantum many-body systems.

Preliminary geologic map of the Black Mountain area northeast of Victorville, San Bernardino County, California

Science.gov (United States)

Stone, Paul

2006-01-01

The Black Mountain area is in the Mojave Desert about 20 km northeast of Victorville, California. The geology of this area is of interest primarily for its excellent exposures of the early Mesozoic Fairview Valley Formation, a sequence of weakly metamorphosed sedimentary rocks including a thick, commercially important unit of limestone conglomerate that has been mined for cement at Black Mountain Quarry for several decades. Recent geochronologic work has shown that the Fairview Valley Formation is probably of Early Jurassic age. This preliminary geologic map of the Black Mountain area depicts the stratigraphic and structural relations of the Fairview Valley Formation and the associated rocks, most notably the overlying Sidewinder Volcanics of Early(?), Middle, and Late(?) Jurassic age. The map is based on new field studies by the author designed to clarify details of the stratigraphy and structure unresolved by previous investigations. The map is considered preliminary because the ages of some geologic units critical for a satisfactory understanding of the stratigraphic and structural framework remain unknown. The map area also includes a segment of the Helendale Fault, one of several faults of known or inferred late Cenozoic right-lateral displacement that make up the Eastern California Shear Zone. The fault is marked by aligned northeast-facing scarps in Pleistocene or older alluvial deposits and the underlying bedrock units. Relations in the map area suggest that right-lateral displacement on the Helendale Fault probably does not exceed 2 km, a conclusion compatible with previous estimates of displacement on this fault based on relations both within and outside the Black Mountain area.

Off-fault ground ruptures in the Santa Cruz Mountains, California: Ridge-top spreading versus tectonic extension during the 1989 Loma Prieta earthquake

Science.gov (United States)

Ponti, Daniel J.; Wells, Ray E.

1991-01-01

The Ms 7.1 Loma Prieta earthquake of 18 October 1989 produced abundant ground ruptures in an 8 by 4 km area along Summit Road and Skyland Ridge in the Santa Cruz Mountains. Predominantly extensional fissures formed a left-stepping, crudely en echelon pattern along ridges of the hanging-wall block southwest of the San Andreas fault, about 12 km northwest of the epicenter. The fissures are subparallel to the San Andreas fault and appear to be controlled by bedding planes, faults, joints, and other weak zones in the underlying Tertiary sedimentary strata of the hanging-wall block. The pattern of extensional fissures is generally consistent with tectonic extension across the crest of the uplifted hanging-wall block. Also, many displacements in Laurel Creek canyon and along the San Andreas and Sargent faults are consistent with right-lateral reverse faulting inferred for the mainshock. Additional small tensile failures along the axis of the Laurel anticline may reflect growth of the fold during deep-seated compression. However, the larger ridge-top fissures commonly have displacements that are parallel to the north-northeast regional slope directions and appear inconsistent with east-northeast extension expected from this earthquake. Measured cumulative displacements across the ridge crests are at least 35 times larger than that predicted by the geodetically determined surface deformation. These fissures also occur in association with ubiquitous landslide complexes that were reactivated by the earthquake to produce the largest concentration of co-seismic slope failures in the epicentral region. The anomalously large displacements and the apparent slope control of the geometry and displacement of many co-seismic surface ruptures lead us to conclude that gravity is an important driving force in the formation of the ridge-top fissures. Shaking-induced gravitational spreading of ridges and downslope movement may account for 90¿ or more of the observed displacements on

StaMPS Improvement for Deformation Analysis in Mountainous Regions: Implications for the Damavand Volcano and Mosha Fault in Alborz

Directory of Open Access Journals (Sweden)

Sanaz Vajedian

2015-06-01

Full Text Available Interferometric Synthetic Aperture Radar (InSAR capability to detect slow deformation over terrain areas is limited by temporal decorrelation, geometric decorrelation and atmospheric artefacts. Multitemporal InSAR methods such as Persistent Scatterer (PS-InSAR and Small Baseline Subset (SBAS have been developed to deal with various aspects of decorrelation and atmospheric problems affecting InSAR observations. Nevertheless, the applicability of both PS-InSAR and SBAS in mountainous regions is still challenging. Correct phase unwrapping in both methods is hampered due to geometric decorrelation in particular when using C-band SAR data for deformation analysis. In this paper, we build upon the SBAS method implemented in StaMPS software and improved the technique, here called ISBAS, to assess tectonic and volcanic deformation in the center of the Alborz Mountains in Iran using both Envisat and ALOS SAR data. We modify several aspects within the chain of the processing including: filtering prior to phase unwrapping, topographic correction within three-dimensional phase unwrapping, reducing the atmospheric noise with the help of additional GPS data, and removing the ramp caused by ionosphere turbulence and/or orbit errors to better estimate crustal deformation in this tectonically active region. Topographic correction is done within the three-dimensional unwrapping in order to improve the phase unwrapping process, which is in contrast to previous methods in which DEM error is estimated before/after phase unwrapping. Our experiments show that our improved SBAS approach is able to better characterize the tectonic and volcanic deformation in the center of the Alborz region than the classical SBAS. In particular, Damavand volcano shows an average uplift rate of about 3 mm/year in the year 2003–2010. The Mosha fault illustrates left-lateral motion that could be explained with a fault that is locked up to 17–18 km depths and slips with 2–4 mm

Geology of the Yucca Mountain Region, Chapter in Stuckless, J.S., ED., Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste

International Nuclear Information System (INIS)

J.S. Stuckless; D. O'Leary

2006-01-01

Yucca Mountain has been proposed as the site for the Nation's first geologic repository for high-level radioactive waste. This chapter provides the geologic framework for the Yucca Mountain region. The regional geologic units range in age from late Precambrian through Holocene, and these are described briefly. Yucca Mountain is composed dominantly of pyroclastic units that range in age from 11.4 to 15.2 Ma. The proposed repository would be constructed within the Topopah Spring Tuff, which is the lower of two major zoned and welded ash-flow tuffs within the Paintbrush Group. The two welded tuffs are separated by the partly to nonwelded Pah Canyon Tuff and Yucca Mountain Tuff, which together figure prominently in the hydrology of the unsaturated zone. The Quaternary deposits are primarily alluvial sediments with minor basaltic cinder cones and flows. Both have been studied extensively because of their importance in predicting the long-term performance of the proposed repository. Basaltic volcanism began about 10 Ma and continued as recently as about 80 ka with the eruption of cones and flows at Lathrop Wells, approximately 10 km south-southwest of Yucca Mountain. Geologic structure in the Yucca Mountain region is complex. During the latest Paleozoic and Mesozoic, strong compressional forces caused tight folding and thrust faulting. The present regional setting is one of extension, and normal faulting has been active from the Miocene through to the present. There are three major local tectonic domains: (1) Basin and Range, (2) Walker Lane, and (3) Inyo-Mono. Each domain has an effect on the stability of Yucca Mountain

Tectonic stability and expected ground motion at Yucca Mountain. Final report. Revision 1. August 7-8, 1984-January 25-26, 1985

International Nuclear Information System (INIS)

1985-12-01

The historic seismic record at Yucca Mountain is too brief and incomplete to provide an accurate assessment of the frequency/magnitude relationship of the quality required to extrapolate future seismicity. The present northwest-southwest extension rate in the general area of Yucca Mountain appears to be of the same order as that across that entire southern Great Basin averaged over the last 15 million years. Thus, Quaternary tectonic activity can be used as a rough indicator of future activity. In situ stress measurements indicate that failure is possible along favorably oriented faults in the Yucca Mountain region. However, no quantitative statements about earthquake probability and magnitude (M) associated with the failure can be determined from in situ data alone. Both weapons tests at the Nevada Test Site (NTS) and impoundment of water at Lake Mead near Las Vegas have induced or triggered earthquakes of magnitudes as high as 4 or 5 within 14 kilometers of those locations. It is quite likely that all faults with significant scarps indicative of large earthquakes (M/sub s/ greater than or equal to 7) during the Quaternary-Holocene have been located and mapped. However, fault segmentation and the possibility of strike-slip motion complicate the precise identification of active faults and potential fault rupture length. Present estimates of peak ground acceleration at Yucca Mountain are based on empirical relationships that were not specifically derived for normal, oblique-slip, or strike-slip faults within an intraplate extensional regime. Thus, they should be evaluated for application to the Yucca Mountain region, assessed for standard error and uncertainties, and updated with more recent empirical data as appropriate. The Death Valley region is about 50 kilometers from Yucca Mountain. This region may have a potential for producing large earthquakes, but more study is required to assess its earthquake capability

Gently dipping normal faults identified with Space Shuttle radar topography data in central Sulawesi, Indonesia, and some implications for fault mechanics

Science.gov (United States)

Spencer, J.E.

2011-01-01

Space-shuttle radar topography data from central Sulawesi, Indonesia, reveal two corrugated, domal landforms, covering hundreds to thousands of square kilometers, that are bounded to the north by an abrupt transition to typical hilly to mountainous topography. These domal landforms are readily interpreted as metamorphic core complexes, an interpretation consistent with a single previous field study, and the abrupt northward transition in topographic style is interpreted as marking the trace of two extensional detachment faults that are active or were recently active. Fault dip, as determined by the slope of exhumed fault footwalls, ranges from 4?? to 18??. Application of critical-taper theory to fault dip and hanging-wall surface slope, and to similar data from several other active or recently active core complexes, suggests a theoretical limit of three degrees for detachment-fault dip. This result appears to conflict with the dearth of seismological evidence for slip on faults dipping less than ~. 30??. The convex-upward form of the gently dipping fault footwalls, however, allows for greater fault dip at depths of earthquake initiation and dominant energy release. Thus, there may be no conflict between seismological and mapping studies for this class of faults. ?? 2011 Elsevier B.V.

Maximum Attainable Accuracy of Inexact Saddle Point Solvers

Czech Academy of Sciences Publication Activity Database

Jiránek, P.; Rozložník, Miroslav

2008-01-01

Roč. 29, č. 4 (2008), s. 1297-1321 ISSN 0895-4798 R&D Projects: GA MŠk 1M0554; GA AV ČR 1ET400300415 Institutional research plan: CEZ:AV0Z10300504 Keywords : saddle point problems * Schur complement reduction * null-space projection method * rounding error analysis Subject RIV: BA - General Mathematics Impact factor: 1.328, year: 2008

Small fishes crossed a large mountain range: Quaternary stream capture events and freshwater fishes on both sides of the Taebaek Mountains.

Science.gov (United States)

Kim, Daemin; Hirt, M Vincent; Won, Yong-Jin; Simons, Andrew M

2017-07-01

The Taebaek Mountains in Korea serve as the most apparent biogeographic barrier for Korean freshwater fishes, resulting in 2 distinct ichthyofaunal assemblages on the eastern (East/Japan Sea slope) and western (Yellow Sea and Korea Strait slopes) sides of the mountain range. Of nearly 100 species of native primary freshwater fishes in Korea, only 18 species occur naturally on both sides of the mountain range. Interestingly, there are 5 rheophilic species (Phoxinus phoxinus, Coreoleuciscus splendidus, Ladislavia taczanowskii, Iksookimia koreensis and Koreocobitis rotundicaudata) found on both sides of the Taebaek Mountains that are geographically restricted to the Osip River (and several neighboring rivers, for L. taczanowskii and I. koreensis) on the eastern side of the mountain range. The Osip River and its neighboring rivers also shared a rheophilic freshwater fish, Liobagrus mediadiposalis, with the Nakdong River on the western side of the mountain range. We assessed historical biogeographic hypotheses on the presence of these rheophilic fishes, utilizing DNA sequence data from the mitochondrial cytochrome b gene. Results of our divergence time estimation indicate that ichthyofaunal transfers into the Osip River (and several neighboring rivers in East Sea slope) have occurred from the Han (Yellow Sea slope) and Nakdong (Korea Strait slope) Rivers since the Late Pleistocene. The inferred divergence times for the ichthyofaunal transfer across the Taebaek Mountains were consistent with the timing of hypothesized multiple reactivations of the Osip River Fault (Late Pleistocene), suggesting that the Osip River Fault reactivations may have caused stream capture events, followed by ichthyofaunal transfer, not only between the Osip and Nakdong Rivers, but also between the Osip and Han Rivers. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Geology of drill hole UE25p No. 1: A test hole into pre-Tertiary rocks near Yucca Mountain, southern Nevada

International Nuclear Information System (INIS)

Carr, M.D.; Waddell, S.J.; Vick, G.S.; Stock, J.M.; Monsen, S.A.; Harris, A.G.; Cork, B.W.; Byers, F.M. Jr.

1986-01-01

Yucca Mountain in southern Nye County, Nevada, has been proposed as a potential site for the underground disposal of high-level nuclear waste. An exploratory drill hole designated UE25p No. 1 was drilled 3 km east of the proposed repository site to investigate the geology and hydrology of the rocks that underlie the Tertiary volcanic and sedimentary rock sequence forming Yucca Mountain. Silurian dolomite assigned to the Roberts Mountain and Lone Mountain Formations was intersected below the Tertiary section between a depth of approximately 1244 m (4080 ft) and the bottom of the drill hole at 1807 m (5923 ft). These formations are part of an important regional carbonate aquifer in the deep ground-water system. Tertiary units deeper than 1139 m (3733 ft) in drill hole UE25p No. 1 are stratigraphically older than any units previously penetrated by drill holes at Yucca Mountain. These units are, in ascending order, the tuff of Yucca Flat, an unnamed calcified ash-flow tuff, and a sequence of clastic deposits. The upper part of the Tertiary sequence in drill hole UE25p No. 1 is similar to that found in other drill holes at Yucca Mountain. The Tertiary sequence is in fault contact with the Silurian rocks. This fault between Tertiary and Paleozoic rocks may correlate with the Fran Ridge fault, a steeply westward-dipping fault exposed approximately 0.5 km east of the drill hole. Another fault intersects UE25p No. 1 at 873 m (2863 ft), but its surface trace is concealed beneath the valley west of the Fran Ridge fault. The Paintbrush Canyon fault, the trace of which passes less than 100 m (330 ft) east of the drilling site, intersects drill hole UE25p No. 1 at a depth of approximately 78 m (255 ft). The drill hole apparently intersected the west flank of a structural high of pre-Tertiary rocks, near the eastern edge of the Crater Flat structural depression

Re-evaluating fault zone evolution, geometry, and slip rate along the restraining bend of the southern San Andreas Fault Zone

Science.gov (United States)

Blisniuk, K.; Fosdick, J. C.; Balco, G.; Stone, J. O.

2017-12-01

This study presents new multi-proxy data to provide an alternative interpretation of the late -to-mid Quaternary evolution, geometry, and slip rate of the southern San Andreas fault zone, comprising of the Garnet Hill, Banning, and Mission Creek fault strands, along its restraining bend near the San Bernardino Mountains and San Gorgonio Pass. Present geologic and geomorphic studies in the region indicate that as the Mission Creek and Banning faults diverge from one another in the southern Indio Hills, the Banning Fault Strand accommodates the majority of lateral displacement across the San Andreas Fault Zone. In this currently favored kinematic model of the southern San Andreas Fault Zone, slip along the Mission Creek Fault Strand decreases significantly northwestward toward the San Gorgonio Pass. Along this restraining bend, the Mission Creek Fault Strand is considered to be inactive since the late -to-mid Quaternary ( 500-150 kya) due to the transfer of plate boundary strain westward to the Banning and Garnet Hills Fault Strands, the Jacinto Fault Zone, and northeastward, to the Eastern California Shear Zone. Here, we present a revised geomorphic interpretation of fault displacement, initial 36Cl/10Be burial ages, sediment provenance data, and detrital geochronology from modern catchments and displaced Quaternary deposits that improve across-fault correlations. We hypothesize that continuous large-scale translation of this structure has occurred throughout its history into the present. Accordingly, the Mission Creek Fault Strand is active and likely a primary plate boundary fault at this latitude.

Geologic map and cross sections of the Embudo Fault Zone in the Southern Taos Valley, Taos County, New Mexico

Science.gov (United States)

Bauer, Paul W.; Kelson, Keith I.; Grauch, V.J.S.; Drenth, Benjamin J.; Johnson, Peggy S.; Aby, Scott B.; Felix, Brigitte

2016-01-01

The southern Taos Valley encompasses the physiographic and geologic transition zone between the Picuris Mountains and the San Luis Basin of the Rio Grande rift. The Embudo fault zone is the rift transfer structure that has accommodated the kinematic disparities between the San Luis Basin and the Española Basin during Neogene rift extension. The eastern terminus of the transfer zone coincides with the intersection of four major fault zones (Embudo, Sangre de Cristo, Los Cordovas, and Picuris-Pecos), resulting in an area of extreme geologic and hydrogeologic complexities in both the basin-fill deposits and the bedrock. Although sections of the Embudo fault zone are locally exposed in the bedrock of the Picuris Mountains and in the late Cenozoic sedimentary units along the top of the Picuris piedmont, the full proportions of the fault zone have remained elusive due to a pervasive cover of Quaternary surficial deposits. We combined insights derived from the latest geologic mapping of the area with deep borehole data and high-resolution aeromagnetic and gravity models to develop a detailed stratigraphic/structural model of the rift basin in the southern Taos Valley area. The four fault systems in the study area overlap in various ways in time and space. Our geologic model states that the Picuris-Pecos fault system exists in the basement rocks (Picuris formation and older units) of the rift, where it is progressively down dropped and offset to the west by each Embudo fault strand between the Picuris Mountains and the Rio Pueblo de Taos. In this model, the Miranda graben exists in the subsurface as a series of offset basement blocks between the Ponce de Leon neighborhood and the Rio Pueblo de Taos. In the study area, the Embudo faults are pervasive structures between the Picuris Mountains and the Rio Pueblo de Taos, affecting all geologic units that are older than the Quaternary surficial deposits. The Los Cordovas faults are thought to represent the late Tertiary to

Holocene earthquakes of magnitude 7 during westward escape of the Olympic Mountains, Washington

Science.gov (United States)

Nelson, Alan R.; Personius, Stephen; Wells, Ray; Schermer, Elizabeth R.; Bradley, Lee-Ann; Buck, Jason; Reitman, Nadine G.

2017-01-01

The Lake Creek–Boundary Creek fault, previously mapped in Miocene bedrock as an oblique thrust on the north flank of the Olympic Mountains, poses a significant earthquake hazard. Mapping using 2015 light detection and ranging (lidar) confirms 2004 lidar mapping of postglacial (≥14  km along a splay fault, the Sadie Creek fault, west of Lake Crescent. Scarp morphology suggests repeated earthquake ruptures along the eastern section of the Lake Creek–Boundary Creek fault and the Sadie Creek fault since ∼13  ka">∼13  ka. Right‐lateral (∼11–28  m">∼11–28  m) and vertical (1–2 m) cumulative fault offsets suggest slip rates of ∼1–2  mm/yr">∼1–2  mm/yr Stratigraphic and age‐model data from five trenches perpendicular to scarps at four sites on the eastern section of the fault show evidence of 3–5 surface‐rupturing earthquakes. Near‐vertical fault dips and upward‐branching fault patterns in trenches, abrupt changes in the thickness of stratigraphic units across faults, and variations in vertical displacement of successive stratigraphic units along fault traces also suggest a large lateral component of slip. Age models suggest two earthquakes date from 1.3±0.8">1.3±0.8 and 2.9±0.6  ka">2.9±0.6  ka; evidence and ages for 2–3 earlier earthquakes are less certain. Assuming 3–5 postglacial earthquakes, lateral and vertical cumulative fault offsets yield average slip per earthquake of ∼4.6  m">∼4.6  m, a lateral‐to‐vertical slip ratio of ∼10:1">∼10:1, and a recurrence interval of 3.5±1.0  ka">3.5±1.0  ka. Empirical relations yield moment magnitude estimates of M 7.2–7.5 (slip per earthquake) and 7.1–7.3 (56 km maximum rupture length). An apparent left‐lateral Miocene to right‐lateral Holocene slip reversal on the faults is probably related to overprinting of east‐directed, accretion‐dominated deformation in the eastern core of the Olympic

Restoration of the Cretaceous uplift of the Harz Mountains, North Germany: evidence for the geometry of a thick-skinned thrust

Science.gov (United States)

Tanner, David C.; Krawczyk, Charlotte M.

2017-04-01

Reverse movement on the Harz Northern Boundary Fault was responsible for the Late Cretaceous uplift of the Harz Mountains in northern Germany. Using the known geometry of the surface position and dip of the fault, and a published cross section of the Base Permian horizon, we show that it is possible to predict the probable shape of the fault at depth, down to a detachment level. We use the `inclined-shear' method with constant heave and argue that a shear angle of 30° was most likely. In this case, the detachment level is at a depth of ca. 25 km. Kinematic restoration of the Harz Mountains using this fault geometry does not produce a flat horizon, rather it results in a ca. 4 km depression. Airy-Heiskanen isostatic equilibrium adjustment of the Harz Mountains restores the Base Permian horizon to the horizontal, as well as raising the Moho to a depth of 32 km, a typical value for northern Germany. Restoration also causes a rotation of tectonic fabrics within the Harz Mountains of about 11° clockwise. We show that this model geometry is very good fit to the interpreted DEKORP BASIN 9601 deep seismic profile.

Active tectonic deformation of the western Indian plate boundary: A case study from the Chaman Fault System

Science.gov (United States)

Crupa, Wanda E.; Khan, Shuhab D.; Huang, Jingqiu; Khan, Abdul S.; Kasi, Aimal

2017-10-01

Collision of the Eurasian and Indian plates has resulted in two spatially offset subduction zones, the Makran subduction zone to the south and the Himalayan convergent margin to the north. These zones are linked by a system of left-lateral strike-slip faults known as the Chaman Fault System, ∼1200 km, which spans along western Pakistan. Although this is one of the greatest strike-slip faults, yet temporal and spatial variation in displacement has not been adequately defined along this fault system. This study conducted geomorphic and geodetic investigations along the Chaman Fault in a search for evidence of spatial variations in motion. Four study areas were selected over the span of the Chaman Fault: (1) Tarnak-Rud area over the Tarnak-Rud valley, (2) Spinatizha area over the Spinatizha Mountain Range, (3) Nushki area over the Nushki basin, and (4) Kharan area over the northern tip of the Central Makran Mountains. Remote sensing data allowed for in depth mapping of different components and faults within the Kohjak group. Wind and water gap pairs along with offset rivers were identified using high-resolution imagery and digital-elevation models to show displacement for the four study areas. The mountain-front-sinuosity ratio, valley height-to-width-ratio, and the stream-length-gradient index were calculated and used to determine the relative tectonic activity of each area. These geomorphic indices suggest that the Kharan area is the most active and the Tarnak-Rud area is the least active. GPS data were processed into a stable Indian plate reference frame and analyzed. Fault parallel velocity versus fault normal distance yielded a ∼8-10 mm/yr displacement rate along the Chaman Fault just north of the Spinatizha area. InSAR data were also integrated to assess displacement rates along the fault system. Geodetic data support that ultra-slow earthquakes similar to those that strike along other major strike-slip faults, such as the San Andreas Fault System, are

Geology of the Yucca Mountain Region, Chapter in Stuckless, J.S., ED., Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste

Energy Technology Data Exchange (ETDEWEB)

J.S. Stuckless; D. O' Leary

2006-09-25

Yucca Mountain has been proposed as the site for the Nation's first geologic repository for high-level radioactive waste. This chapter provides the geologic framework for the Yucca Mountain region. The regional geologic units range in age from late Precambrian through Holocene, and these are described briefly. Yucca Mountain is composed dominantly of pyroclastic units that range in age from 11.4 to 15.2 Ma. The proposed repository would be constructed within the Topopah Spring Tuff, which is the lower of two major zoned and welded ash-flow tuffs within the Paintbrush Group. The two welded tuffs are separated by the partly to nonwelded Pah Canyon Tuff and Yucca Mountain Tuff, which together figure prominently in the hydrology of the unsaturated zone. The Quaternary deposits are primarily alluvial sediments with minor basaltic cinder cones and flows. Both have been studied extensively because of their importance in predicting the long-term performance of the proposed repository. Basaltic volcanism began about 10 Ma and continued as recently as about 80 ka with the eruption of cones and flows at Lathrop Wells, approximately 10 km south-southwest of Yucca Mountain. Geologic structure in the Yucca Mountain region is complex. During the latest Paleozoic and Mesozoic, strong compressional forces caused tight folding and thrust faulting. The present regional setting is one of extension, and normal faulting has been active from the Miocene through to the present. There are three major local tectonic domains: (1) Basin and Range, (2) Walker Lane, and (3) Inyo-Mono. Each domain has an effect on the stability of Yucca Mountain.

Evaluation of the potential for surface faulting at TA-63. Final report

International Nuclear Information System (INIS)

Kolbe, T.; Sawyer, J.; Springer, J.; Olig, S.; Hemphill-Haley, M.; Wong, I.; Reneau, S.

1995-01-01

This report describes an investigation of the potential for surface faulting at the proposed sites for the Radioactive Liquid Waste Treatment Facility (RL)WF) and the Hazardous Waste Treatment Facility at TA-63 and TA-52 (hereafter TA-63), Los Alamos National Laboratory (LANL). This study was performed by Woodward-Clyde Federal Services (WCFS) at the request of the LANL. The projections of both the Guaje Mountain and Rendija Canyon faults are mapped in the vicinity of TA-63. Based on results obtained in the ongoing Seismic Hazard Evaluation Program of the LANL, displacement may have occurred on both the Guaje Mountain and Rendija Canyon faults in the past 11,000 years (Holocene time). Thus, in accordance with US Department of Energy (DOE) Orders and Standards for seismic hazards evaluations and the US Environmental Protection Agency (EPA) Resource Conservation and Recovery Act (RCRA) Regulations for seismic standard requirements, a geologic study of the proposed TA-63 site was conducted

Reverse fault growth and fault interaction with frictional interfaces: insights from analogue models

Science.gov (United States)

Bonanno, Emanuele; Bonini, Lorenzo; Basili, Roberto; Toscani, Giovanni; Seno, Silvio

2017-04-01

The association of faulting and folding is a common feature in mountain chains, fold-and-thrust belts, and accretionary wedges. Kinematic models are developed and widely used to explain a range of relationships between faulting and folding. However, these models may result not to be completely appropriate to explain shortening in mechanically heterogeneous rock bodies. Weak layers, bedding surfaces, or pre-existing faults placed ahead of a propagating fault tip may influence the fault propagation rate itself and the associated fold shape. In this work, we employed clay analogue models to investigate how mechanical discontinuities affect the propagation rate and the associated fold shape during the growth of reverse master faults. The simulated master faults dip at 30° and 45°, recalling the range of the most frequent dip angles for active reverse faults that occurs in nature. The mechanical discontinuities are simulated by pre-cutting the clay pack. For both experimental setups (30° and 45° dipping faults) we analyzed three different configurations: 1) isotropic, i.e. without precuts; 2) with one precut in the middle of the clay pack; and 3) with two evenly-spaced precuts. To test the repeatability of the processes and to have a statistically valid dataset we replicate each configuration three times. The experiments were monitored by collecting successive snapshots with a high-resolution camera pointing at the side of the model. The pictures were then processed using the Digital Image Correlation method (D.I.C.), in order to extract the displacement and shear-rate fields. These two quantities effectively show both the on-fault and off-fault deformation, indicating the activity along the newly-formed faults and whether and at what stage the discontinuities (precuts) are reactivated. To study the fault propagation and fold shape variability we marked the position of the fault tips and the fold profiles for every successive step of deformation. Then we compared

Revised potentiometric-surface map, Yucca Mountain and vicinity, Nevada

International Nuclear Information System (INIS)

Ervin, E.M.; Luckey, R.R.; Burkhardt, D.J.

1994-01-01

The revised potentiometric-surface map presented in this report updates earlier maps of the Yucca Mountain area using mainly 1988 average water levels. Because of refinements in the corrections to the water-level measurements, these water levels have increased accuracy and precision over older values. The small-gradient area to the southeast of Yucca Mountain is contoured with a 0.25-meter interval and ranges in water-level altitude from 728.5 to 73 1.0 meters. Other areas with different water levels, to the north and west of Yucca Mountain, are illustrated with shaded patterns. The potentiometric surface can be divided into three regions: (1) A small-gradient area to the southeast of Yucca Mountain, which may be explained by flow through high-transmissivity rocks or low ground-water flux through the area; (2) A moderate-gradient area, on the western side of Yucca Mountain, where the water-level altitude ranges from 775 to 780 meters, and appears to be impeded by the Solitario Canyon Fault and a splay of that fault; and (3) A large-gradient area, to the north-northeast of Yucca Mountain, where water level altitude ranges from 738 to 1,035 meters, possibly as a result of a semi-perched groundwater system. Water levels from wells at Yucca Mountain were examined for yearly trends using linear least-squares regression. Data from five wells exhibited trends which were statistically significant, but some of those may be a result of slow equilibration of the water level from drilling in less permeable rocks. Adjustments for temperature and density changes in the deep wells with long fluid columns were attempted, but some of the adjusted data did not fit the surrounding data and, thus, were not used

Identification of a mutation that is associated with the saddle tan and black-and-tan phenotypes in Basset Hounds and Pembroke Welsh Corgis.

Science.gov (United States)

Dreger, Dayna L; Parker, Heidi G; Ostrander, Elaine A; Schmutz, Sheila M

2013-01-01

The causative mutation for the black-and-tan (a (t) ) phenotype in dogs was previously shown to be a SINE insertion in the 5' region of Agouti Signaling Protein (ASIP). Dogs with the black-and-tan phenotype, as well as dogs with the saddle tan phenotype, genotype as a (t) /_ at this locus. We have identified a 16-bp duplication (g.1875_1890dupCCCCAGGTCAGAGTTT) in an intron of hnRNP associated with lethal yellow (RALY), which segregates with the black-and-tan phenotype in a group of 99 saddle tan and black-and-tan Basset Hounds and Pembroke Welsh Corgis. In these breeds, all dogs with the saddle tan phenotype had RALY genotypes of +/+ or +/dup, whereas dogs with the black-and-tan phenotype were homozygous for the duplication. The presence of an a (y) /_ fawn or e/e red genotype is epistatic to the +/_ saddle tan genotype. Genotypes from 10 wolves and 1 coyote indicated that the saddle tan (+) allele is the ancestral allele, suggesting that black-and-tan is a modification of saddle tan. An additional 95 dogs from breeds that never have the saddle tan phenotype have all three of the possible RALY genotypes. We suggest that a multi-gene interaction involving ASIP, RALY, MC1R, DEFB103, and a yet-unidentified modifier gene is required for expression of saddle tan.

Late Miocene-Recent evolution of the Finike Basin and its linkages with the Beydağlari complex and the Anaximander Mountains, eastern Mediterranean

Science.gov (United States)

Aksu, A. E.; Hall, J.; Yaltırak, C.; Çınar, E.; Küçük, M.; Çifçi, G.

2014-11-01

Interpretation of ~ 2500 km of high-resolution multi-channel seismic reflection profiles shows that the Finike Basin evolved during the Pliocene-Quaternary as the result of dramatic subsidence associated with loading of large imbricate thrust panels that carry the western Tauride Mountains in the north in the Late Miocene. The stacked, seaward prograded Quaternary deltas presently resting at 1000-1500 m water depths corroborate the rapid subsidence of the region. The ubiquitous presence of evaporites in the 2000-2400 m-deep Antalya Basin and their absence in the 3000-3200 m deep Finike Basin suggest that the morphology of the Finike Basin and environs must have been considerably different during the Messinian and that this region must have remained above the depositional base of evaporites during this time. The transition from the Messinian to the Pliocene-Quaternary is marked by partitioning of stress into several discrete spatial domains. A dextral strike-slip fault zone developed along the western Antalya Basin, extending from the apex of the Isparta Angle southward into the Anaximander Mountains. This fault zone, referred to as the Antalya Fault zone, transected the Anaximander Mountains (sensu lato) separating the Anaxagoras Mountain from the Anaximander and Anaximenes Mountains. Hence, the Finike Basin, Sırrı Erinç Plateau and the Anaximander and Anaximenes Mountains remained part of the onland Beydağları Block and experienced ~ 20° counterclockwise rotation during the Late Miocene. We envisage the boundaries of the Beydağları Block as the Burdur-Fethiye Fault zone in the west, the newly delineated Antalya Fault zone in the east and the east-west trending sector of the Sırrı Erinç Plateau in the southwest. Kinematic evaluation of the structural elements mapped across the Finike Basin and the Sırrı Erinç Plateau suggest that two additional strike-slip zones developed during the Pliocene-Quaternary relaying the stress between the Antalya Fault

Unified analysis of preconditioning methods for saddle point matrices

Czech Academy of Sciences Publication Activity Database

Axelsson, Owe

2015-01-01

Roč. 22, č. 2 (2015), s. 233-253 ISSN 1070-5325 R&D Projects: GA MŠk ED1.1.00/02.0070 Institutional support: RVO:68145535 Keywords : saddle point problems * preconditioning * spectral properties Subject RIV: BA - General Mathematics Impact factor: 1.431, year: 2015 http://onlinelibrary.wiley.com/doi/10.1002/nla.1947/pdf

Surface plasma source with saddle antenna radio frequency plasma generator.

Science.gov (United States)

Dudnikov, V; Johnson, R P; Murray, S; Pennisi, T; Piller, C; Santana, M; Stockli, M; Welton, R

2012-02-01

A prototype RF H(-) surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA∕kW. Control experiments with H(-) beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

Localized saddle-point search and application to temperature-accelerated dynamics

Energy Technology Data Exchange (ETDEWEB)

Shim, Yunsic; Amar, Jacques G. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Callahan, Nathan B. [Department of Physics and Astronomy, University of Toledo, Toledo, Ohio 43606 (United States); Department of Physics, Indiana University, Bloomington, Indiana 47405 (United States)

2013-03-07

We present a method for speeding up temperature-accelerated dynamics (TAD) simulations by carrying out a localized saddle-point (LSAD) search. In this method, instead of using the entire system to determine the energy barriers of activated processes, the calculation is localized by only including a small chunk of atoms around the atoms directly involved in the transition. Using this method, we have obtained N-independent scaling for the computational cost of the saddle-point search as a function of system size N. The error arising from localization is analyzed using a variety of model systems, including a variety of activated processes on Ag(100) and Cu(100) surfaces, as well as multiatom moves in Cu radiation damage and metal heteroepitaxial growth. Our results show significantly improved performance of TAD with the LSAD method, for the case of Ag/Ag(100) annealing and Cu/Cu(100) growth, while maintaining a negligibly small error in energy barriers.

Miscellaneous investigations series: Bedrock geologic map of the Lone Mountain pluton area, Esmeralda County, Nevada

International Nuclear Information System (INIS)

Maldonado, F.

1984-01-01

The joint attitudes were measured in the field and plotted on aerial photos at a scale of 1:24,000. The pluton is intensely jointed, primarily as a result of cooling and movement of the magma within a northwest-trending stress field. Foliation, in general, is poorly developed, and quality varies from area to area, but it is best developed close to the contacts with the metasedimentary rocks. A prominent northwest foliation direction was observed that parallels the northwest elongation of the exposed pluton. Faults in the pluton are difficult to identify because of the homogeneity of the rock. Several faults were mapped in the northern part of the area where they have a northeast trend and intersect the northwest-trending lamprophyre dikes with little apparent displacement. A major fault that bounds the northern part of the pluton is downthrown to the north and strikes northeast. This fault offsets the alluvium, the metasedimentary rocks, and the pluton and forms fault scraps as high as 10 m. Aeromagnetic data (US Geological Survey, 1979) suggest the following: (1) the local magnetic highs in the central part of the Lone Mountain pluton are probably related to topographic highs (peaks) where the flight lines are closer to the pluton; (2) a magnetic low in the northeastern part of Lone Mountain coincides with the pluton-country rock contact, which may be very steep; (3) the contours for the southwestern part of the mapped area indicate that the pluton-country rock contact is not as steep as that in the northeastern part and that the pluton probably coalesces at depth with the Weepah pluton, a pluton exposed south of the mapped area; and (4) the contours for the area of the Lone Mountain pluton express a northwest-trending gradient that parallels the northwest elongation of the Lone Mountain pluton and the northwest-trending stress field. 10 refs

Effect of saddle-point anisotropy on point-defect drift-diffusion into straight dislocations

International Nuclear Information System (INIS)

Skinner, B.C.; Woo, C.H.

1983-02-01

Effects on point-defect drift-diffusion in the strain fields of edge or screw dislocations, due to the anisotropy of the point defect in its saddle-point configuration, are investigated. Expressions for sink strength and bias that include the saddle-point shape effect are derived, both in the absence and presence of an externally applied stress. These are found to depend on intrinsic parameters such as the relaxation volume and the saddle-point shape of the point defects, and extrinsic parameters such as temperature and the magnitude and direction of the externally applied stress with respect to the line direction and Burgers vector direction of the dislocation. The theory is applied to fcc copper and bcc iron. It is found that screw dislocations are biased sinks and that the stress-induced bias differential for the edge dislocations depends much more on the line direction than the Burgers vector direction. Comparison with the stress-induced bias differential due to the usual SIPA effect is made. It is found that the present effect causes a bias differential that is more than an order of magnitude larger

Characterization of the Highway 95 Fault in lower Fortymile Wash using electrical and electromagnetic methods, Nye County, Nevada

Science.gov (United States)

Macy, Jamie P.; Kryder, Levi; Walker, Jamieson

2012-01-01

The Highway 95 Fault is a buried, roughly east-west trending growth fault at the southern extent of Yucca Mountain and Southwestern Nevada Volcanic Field. Little is known about the role of this fault in the movement of groundwater from the Yucca Mountain area to downgradient groundwater users in Amargosa Valley. The U.S. Geological Survey (USGS) Arizona Water Science Center (AZWSC), in cooperation with the Nye County Nuclear Waste Repository Project Office (NWRPO), has used direct current (DC) resistivity, controlled-source audio magnetotelluric (CSAMT), and transient electromagnetics (TEM) to better understand the fault. These geophysical surveys were designed to look at structures buried beneath the alluvium, following a transect of wells for lithologic control. Results indicate that the fault is just north of U.S. Highway 95, between wells NC-EWDP-2DB and -19D, and south of Highway 95, east of well NC-EWDP-2DB. The Highway 95 Fault may inhibit shallow groundwater movement by uplifting deep Paleozoic carbonates, effectively reducing the overlying alluvial aquifer thickness and restricting the movement of water. Upward vertical hydraulic gradients in wells proximal to the fault indicate that upward movement is occurring from deeper, higher-pressure aquifers.

The evolution, argon diffusion properties, and 40Argon/39Argon ages of detachment-related fault rocks in the footwalls of the Whipple and Chemehuevi Mountains, Southeastern, California

Science.gov (United States)

Hazelton, Garrett Blaine

Furnace and laser spot methods of obtaining 40Ar/ 39Ar ages from fine-grained cataclasite and pseudotachylyte are compared and evaluated in terms of protolith, faulting, and cooling age components. These methods are applied to fault rocks from outcrop-scale, small-displacement, brittle detachment faults (minidetachments or MDF's) that cut mid-crustal rocks from the footwalls of brittle, large-displacement (>20 km), top-to-the-NE, low-angle normal (i.e., detachment) faults in the Whipple (WM) and Chemehuevi Mountains (CM), SE California. Mid-Tertiary extension affected both areas from ˜26 Ma to ˜11--8 Ma. Rapid footwall cooling began at ˜22 Ma. WM-CM furnace ages range from 22.0 +/- 1.3 to 14.6 +/- 0.6 Ma, CM laser ages from 29.9 +/- 3.7 to 15.7 +/- 1.2 Ma. These ages are younger than host protolith formation and record detachment faulting or footwall cooling. At least 50 MDF's were mapped; they typically cut all basement fabrics. Brittle MDFand detacriment-generated fault rocks are texturally similar, but some in the WM are plastically deformed. Fault rock matrix was mechanically extracted, optically studied, probed to characterize bulk mineralogy. K-feldspar grains are the primary source of fault rock-derived Ar. The laser provides high spatial resolution and the furnace method yields the Ar diffusion properties of fault rock matrix. Both methods yield reproducible results, but ages are difficult to interpret without an established geothermochronologic context. Fault rock 40Ar/39Ar measurements reveal: (1) closure temperatures of 140--280°C (at 100°C/Myr); (2) activation energies ranging from 33--50 kcal/mol; (3) individual K-feldspar grain ages of 55--5 Ma; (4) unanticipated and poorly understood low-temperature diffusion behavior; (5) little difference between pseudotachylyte and cataclasite matrix diffusion and age results; (6) that pre-analysis sample characterization is requisite. The diffusion properties of prepared glasses (47--84% SiO2) were also

Preliminary gravity and magnetic models across Midway Valley and Yucca Wash, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Ponce, D.A.; Langenheim, V.E.

1994-01-01

Detailed gravity and ground magnetic data collected along ten traverses across Midway Valley and Yucca Wash on the eastern flank of Yucca Mountain in southwest Nevada are interpreted. These data were collected as part of an effort to evaluate faulting in the vicinity of proposed surface facilities for a potential nuclear waste repository at Yucca Mountain. Geophysical data show that Midway Valley is bounded by large gravity and magnetic anomalies associated with the Bow Ridge and Paintbrush Canyon faults, on the west side of Exile Hill and on the west flank of Fran Ridge, respectively. In addition, Midway Valley itself is characterized by a number of small-amplitude anomalies that probably reflect small-scale faulting beneath Midway Valley. Gravity and magnetic data across the northwest trending Yucca Wash and the inferred Yucca Wash fault indicate no major vertical offsets greater than 100 m using a density contrast of 0.2 to 0.3 g/cm 3 along the proposed Yucca Wash fault. In addition, a broad magnetic high coincides with the approximate location of the hydrologic gradient and probably reflects moderately magnetic Topopah Spring Tuff or lavas in the Calico Hills Formation

Tunneling progress on the Yucca Mountain Project

International Nuclear Information System (INIS)

Hansmire, W.H.; Munzer, R.J.

1996-01-01

The current status of tunneling progress on the Yucca Mountain Project (YMP) is presented in this paper. The Exploratory Studies Facility (ESF), a key part of the YMP, has been long in development and construction is ongoing. This is a progress report on the tunneling aspects of the ESF as of January 1, 1996. For purposes of discussion in this summary, the tunneling has progressed in four general phases. The paper describes: tunneling in jointed rock under low stress; tunneling through the Bow Ridge Fault and soft rock; tunneling through the Imbricate Fault Zone; and Tunneling into the candidate repository formation

The use of TOUGH2 for the LBL/USGS 3-dimensional site-scale model of Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Bodvarsson, G.; Chen, G.; Haukwa, C.; Kwicklis, E.

1995-01-01

The three-dimensional site-scale numerical model o the unsaturated zone at Yucca Mountain is under continuous development and calibration through a collaborative effort between Lawrence Berkeley Laboratory (LBL) and the United States Geological Survey (USGS). The site-scale model covers an area of about 30 km 2 and is bounded by major fault zones to the west (Solitario Canyon Fault), east (Bow Ridge Fault) and perhaps to the north by an unconfirmed fault (Yucca Wash Fault). The model consists of about 5,000 grid blocks (elements) with nearly 20,000 connections between them; the grid was designed to represent the most prevalent geological and hydro-geological features of the site including major faults, and layering and bedding of the hydro-geological units. Submodels are used to investigate specific hypotheses and their importance before incorporation into the three-dimensional site-scale model. The primary objectives of the three-dimensional site-scale model are to: (1) quantify moisture, gas and heat flows in the ambient conditions at Yucca Mountain, (2) help in guiding the site-characterization effort (primarily by USGS) in terms of additional data needs and to identify regions of the mountain where sufficient data have been collected, and (3) provide a reliable model of Yucca Mountain that is validated by repeated predictions of conditions in new boreboles and the ESF and has therefore the confidence of the public and scientific community. The computer code TOUGH2 developed by K. Pruess at LBL was used along with the three-dimensional site-scale model to generate these results. In this paper, we also describe the three-dimensional site-scale model emphasizing the numerical grid development, and then show some results in terms of moisture, gas and heat flow

Intrinsic And Extrinsic Controls On Unsteady Deformation Rates, Northern Apennine Mountains, Italy

Science.gov (United States)

Anastasio, D. J.; Gunderson, K. L.; Pazzaglia, F. J.; Kodama, K. P.

2017-12-01

The slip rates of faults in the Northern Apennine Mountains were unsteady at 104-105 year timescales during the Neogene and Quaternary. Fault slip rates were recovered from growth strata and uplifted fluvial terraces associated with the Salsomaggiore, Quatto Castella, and Castevetro fault-related folds, sampled along the Stirone, Enza, and Panaro Rivers, respectively. The forelimb stratigraphy of each anticline was dated using rock magnetic-based cyclostratigraphy, which varies with Milankovitch periodicity, multispecies biostratigraphy, magnetostratigraphy, OSL luminescence dating, TCN burial dating, and radiocarbon dating of uplifted and folded fluvial terraces. Fault slip magnitudes were constrained with trishear forward models. We observed decoupled deformation and sediment accumulation rates at each structure. From 3.5Ma deformation of a thick and thin-skinned thrusts was temporally variable and controlled by intrinsic rock processes, whereas, the more regional Pede-Apenninic thrust fault, a thick-skinned thrust underlying the mountain front, was likely activated because of extrinsic forcing from foreland basin sedimentation rate accelerations since 1.4Ma. We found that reconstructed slip rate variability increased as the time resolution increased. The reconstructed slip history of the thin-skinned thrust faults was characterized relatively long, slow fold growth and associated fault slip, punctuated by shorter, more rapid periods limb rotation, and slip on the underlying thrust fault timed asynchronously. Thrust fault slip rates slip rates were ≤ 0.1 to 6 mm/yr at these intermediate timescales. The variability of slip rates on the thrusts is likely related to strain partitioning neighboring faults within the orogenic wedge. The studied structures slowed down at 1Ma when there was a switch to slower synchronous fault slip coincident with orogenic wedge thickening due to the emplacement of the out of sequence Pene-Apenninic thrust fault that was emplaced at 1

Geology of the Wallula Gap Area, Washington

International Nuclear Information System (INIS)

Gardner, J.N.; Snow, M.G.; Fecht, K.R.

1981-12-01

This study focuses on the structure and stratigraphy of an 80-km 2 area at the southern margin of the Pasco Basin in Wallula Gap. Field stratigraphy, petrography, natural remanent magnetism, and major-element chemistry indicate that the tholeiitic basalt flows of the Wallula Gap area correlate with units of the Grande Ronde, Wanapum, and Saddle Mountains Formations of the Yakima Subgroup of the Columbia River Basalt Group. Flows of the Frenchman Springs, Umatilla, Pomona, Elephant Mountain, and Ice Harbor Mmebers are present in the area. The Frenchman Springs Member exposed in the Wallula Gap is more than 185 m thick and consists of eight to nine flows. Its thickness and possible contemporaneous structural deformation apparently prevented emplacement of both the Roza and Priest Rapids Members at this locality. Structural uplift of the Horse Heaven Hills began prior to extrusion of the Pomona flow. Both the Pomona and Elephant Mountain Members thin and pinch out over the crest of the uplift near Mound Pond. The Ice Harbor flow was apparently confined to the basin north of the Horse Heaven uplift, but an exposure at Mound Pond suggests it flowed through Wallula Gap as an intracanyon flow. The Wallula Gap fault zone trends N65 0 W and can be traced for at least 11 km along the north flank of the Horse Heaven Hills uplift. Where the fault intersects the Olympic-Wallowa Lineament at Van Sycle Canyon 8 km east of Wallula Gap, it is a broad zone of normal faulting, 300 m wide, with as much as 310 m of displacement of the basalt stratigraphy. Two faults occur in the northern portion of Van Sycle Canyon and define a graben trending N45 0 W. A third fault, roughly parallel to the Wallula Gap fault, transects the The Nub and offsets 14 m of Ice Harbor basalt

Preliminary description of quaternary and late pliocene surficial deposits at Yucca Mountain and vicinity, Nye County, Nevada

International Nuclear Information System (INIS)

Hoover, D.L.

1989-01-01

The Yucca Mountain area, in the south-central part of the Great Basin, is in the drainage basin of the Amargosa River. The mountain consists of several fault blocks of volcanic rocks that are typical of the Basin and Range province. Yucca Mountain is dissected by steep-sided valleys of consequent drainage systems that are tributary on the east side to Fortymile Wash and on the west side to an unnamed wash that drains Crater Flat. Most of the major washes near Yucca Mountain are not integrated with the Amargosa River, but have distributary channels on the piedmont above the river. Landforms in the Yucca Mountain area include rock pediments, ballenas, alluvial pediments, alluvial fans, stream terraces, and playas. Early Holocene and older alluvial fan deposits have been smoothed by pedimentation. The semiconical shape of alluvial fans is apparent at the junction of tributaries with major washes and where washes cross fault and terrace scarps. Playas are present in the eastern and southern ends of the Amargosa Desert. 39 refs., 9 figs., 1 tab

Effects of structural heterogeneity on frictional heating from biomarker thermal maturity analysis of the Muddy Mountain thrust, Nevada, USA

Science.gov (United States)

Coffey, G. L.; Savage, H. M.; Polissar, P. J.; Rowe, C. D.

2017-12-01

Faults are generally heterogeneous along-strike, with changes in thickness and structural complexity that should influence coseismic slip. However, observational limitations (e.g. limited outcrop or borehole samples) can obscure this complexity. Here we investigate the heterogeneity of frictional heating determined from biomarker thermal maturity and microstructural observations along a well-exposed fault to understand whether coseismic stress and frictional heating are related to structural complexity. We focus on the Muddy Mountain thrust, Nevada, a Sevier-age structure that has continuous exposure of its fault core and considerable structural variability for up to 50 m, to explore the distribution of earthquake slip and temperature rise along strike. We present new biomarker thermal maturity results that capture the heating history of fault rocks. Biomarkers are organic molecules produced by living organisms and preserved in the rock record. During heating, their structure is altered systematically with increasing time and temperature. Preliminary results show significant variability in thermal maturity along-strike at the Muddy Mountain thrust, suggesting differences in coseismic temperature rise on the meter- scale. Temperatures upwards of 500°C were generated in the principal slip zone at some locations, while in others, no significant temperature rise occurred. These results demonstrate that stress or slip heterogeneity occurred along the Muddy Mountain thrust at the meter-scale and considerable along-strike complexity existed, highlighting the importance of careful interpretation of whole-fault behavior from observations at a single point on a fault.

Major results of gravity and magnetic studies at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Oliver, H.W.; Ponce, D.A.; Sikora, R.F.

1991-01-01

About 4000 gravity stations have been obtained at Yucca Mountain and vicinity since the beginning of radioactive-waste studies there in 1978. These data have been integrated with data from about 29,000 stations previously obtained in the surrounding region to produce a series of Bouguer and isostatic-residual-gravity maps of the Nevada Test Site and southeastern Nevada. Yucca Mountain is characterized by a WNW-dipping gravity gradient whereby residual values of -10 mGal along the east edge of Yucca Mountain decrease to about -38 mGal over Crater Flat. Using these gravity data, two-dimensional modeling predicted the depth to pre-Cenozoic rocks near the proposed repository to be about 1220 ± 150 m, an estimate that was subsequently confirmed by drilling to be 1244 m. Three-dimensional modeling of the gravity low over Crater Flat indicates the thickness of Cenozoic volcanic rocks and alluvial cover to be about 3000 m. Considerable aeromagnetic coverage of southwestern Nevada was obtained in 1978--1979 to help characterize Yucca Mountain and vicinity. One significant result is the discovery of a series of circular magnetic anomalies in Crater Flat and the northern Amargosa Desert that suggest the presence of buried volcanic centers there. Elongate magnetic highs and associated lows over Yucca Mountain correlate with mapped faults, some of which are only partially exposed. Thus, the data provide inforamtion on the extent and continuity of these faults. 31 refs., 3 figs

Late Neogene deformation of the Chocolate Mountains Anticlinorium: Implications for deposition of the Bouse Formation and early evolution of the Lower Colorado River

Science.gov (United States)

Beard, Sue; Haxel, Gordon B.; Dorsey, Rebecca J.; McDougall, Kristin A.; Jacobsen, Carl E.

2016-01-01

Deformation related to late Neogene dextral shear can explain a shift from an estuarine to lacustrine depositional environment in the southern Bouse Formation north of Yuma, Arizona. We infer that late Neogene deformation in the Chocolate Mountain Anticlinorium (CMA) created a barrier that blocked an estuary inlet, and that pre-existing and possibly active structures subsequently controlled the local course of the lower Colorado River. Structural patterns summarized below suggest that the CMA absorbed transpressional strain caused by left-stepping segments of dextral faults of the San Andreas fault system and/or the eastern California shear zone and Gulf of California shear zone. For this hypothesis to be correct, about 200-250 m of post-6 Ma, pre- ~5.3 Ma uplift along the CMA crest would be required to cut off a marine inlet. The 220-km-long CMA, cored by the early Paleogene Orocopia Schist subduction complex, extends from the Orocopia Mountains (Calif.) southeastward through the Chocolate Mountains (parallel to the southern San Andreas fault). Where Highway 78 crosses the Chocolate Mountains (Fig. 1), the CMA turns eastward through the Black Mountain-Picacho area (Calif.) and Trigo Mountains (Ariz.) into southwest Arizona. It separates southernmost Bouse Formation outcrops of the Blythe basin from subsurface Bouse outcrops to the south in the Yuma area. South of Blythe basin the CMA is transected by the lower Colorado River along a circuitous path. Here we focus on the geology of an area between the central Chocolate Mountains and the Yuma Proving Grounds in Arizona. Specific landmarks include the southeast Chocolate Mountains, Midway Mountains, Peter Kane Mountain, Black Mountain, Picacho Peak, and Gavilan Hills. For simplicity, we refer to this as the eastern Chocolate Mountains.

Resurvey of site stability quadrilaterals, Otay Mountain and Quincy, California. [San Andreas fault experiment

Science.gov (United States)

Scholz, C. H.

1977-01-01

Trilateration quadrilaterals established across two faults near the San Andreas Fault Experiment laser/satellite ranging sites were resurveyed after four years. No evidence of significant tectonic motion was found.

Spike-adding in parabolic bursters: The role of folded-saddle canards

Science.gov (United States)

Desroches, Mathieu; Krupa, Martin; Rodrigues, Serafim

2016-09-01

The present work develops a new approach to studying parabolic bursting, and also proposes a novel four-dimensional canonical and polynomial-based parabolic burster. In addition to this new polynomial system, we also consider the conductance-based model of the Aplysia R15 neuron known as the Plant model, and a reduction of this prototypical biophysical parabolic burster to three variables, including one phase variable, namely the Baer-Rinzel-Carillo (BRC) phase model. Revisiting these models from the perspective of slow-fast dynamics reveals that the number of spikes per burst may vary upon parameter changes, however the spike-adding process occurs in an explosive fashion that involves special solutions called canards. This spike-adding canard explosion phenomenon is analysed by using tools from geometric singular perturbation theory in tandem with numerical bifurcation techniques. We find that the bifurcation structure persists across all considered systems, that is, spikes within the burst are incremented via the crossing of an excitability threshold given by a particular type of canard orbit, namely the true canard of a folded-saddle singularity. However there can be a difference in the spike-adding transitions in parameter space from one case to another, according to whether the process is continuous or discontinuous, which depends upon the geometry of the folded-saddle canard. Using these findings, we construct a new polynomial approximation of the Plant model, which retains all the key elements for parabolic bursting, including the spike-adding transitions mediated by folded-saddle canards. Finally, we briefly investigate the presence of spike-adding via canards in planar phase models of parabolic bursting, namely the theta model by Ermentrout and Kopell.

Krylov Subspace Methods for Saddle Point Problems with Indefinite Preconditioning

Czech Academy of Sciences Publication Activity Database

Rozložník, Miroslav; Simoncini, V.

2002-01-01

Roč. 24, č. 2 (2002), s. 368-391 ISSN 0895-4798 R&D Projects: GA ČR GA101/00/1035; GA ČR GA201/00/0080 Institutional research plan: AV0Z1030915 Keywords : saddle point problems * preconditioning * indefinite linear systems * finite precision arithmetic * conjugate gradients Subject RIV: BA - General Mathematics Impact factor: 0.753, year: 2002

On the Use of the Main-sequence Knee (Saddle) to Measure Globular Cluster Ages

Science.gov (United States)

Saracino, S.; Dalessandro, E.; Ferraro, F. R.; Lanzoni, B.; Origlia, L.; Salaris, M.; Pietrinferni, A.; Geisler, D.; Kalirai, J. S.; Correnti, M.; Cohen, R. E.; Mauro, F.; Villanova, S.; Moni Bidin, C.

2018-06-01

In this paper, we review the operational definition of the so-called main-sequence knee (MS-knee), a feature in the color-magnitude diagram (CMD) occurring at the low-mass end of the MS. The magnitude of this feature is predicted to be independent of age at fixed chemical composition. For this reason, its difference in magnitude with respect to the MS turn-off (MS-TO) point has been suggested as a possible diagnostic to estimate absolute globular cluster (GC) ages. We first demonstrate that the operational definition of the MS-knee currently adopted in the literature refers to the inflection point of the MS (which we here more appropriately named MS-saddle), a feature that is well distinct from the knee and which cannot be used as its proxy. The MS-knee is only visible in near-infrared CMDs, while the MS-saddle can be also detected in optical–NIR CMDs. By using different sets of isochrones, we then demonstrate that the absolute magnitude of the MS-knee varies by a few tenths of a dex from one model to another, thus showing that at the moment stellar models may not capture the full systematic error in the method. We also demonstrate that while the absolute magnitude of the MS-saddle is almost coincident in different models, it has a systematic dependence on the adopted color combinations which is not predicted by stellar models. Hence, it cannot be used as a reliable reference for absolute age determination. Moreover, when statistical and systematic uncertainties are properly taken into account, the difference in magnitude between the MS-TO and the MS-saddle does not provide absolute ages with better accuracy than other methods like the MS-fitting.

From the central Jura mountains to the molasse basin (France and Switzerland)

International Nuclear Information System (INIS)

Sommaruga, A.

2011-01-01

This illustrated article discusses the geology of the area covering the Swiss Jura chain of mountains and the molasse basin which is to be found to the south-east of the mountain chain. The geological setting with the Jura Mountains and the molasse basin are described, as are the rocks to be found there. Their structures and faults are discussed in detail and their origin and formation are described. The paper presents a number of geological profiles and maps. The methods used to explore these structures are noted, which also indicated the presence of permo-carboniferous troughs in the molasse basin

From the central Jura mountains to the molasse basin (France and Switzerland)

Energy Technology Data Exchange (ETDEWEB)

Sommaruga, A. [Institut de Géophysique, University of Lausanne, Bâtiment Amphipôle, Lausanne (Switzerland)

2011-07-01

This illustrated article discusses the geology of the area covering the Swiss Jura chain of mountains and the molasse basin which is to be found to the south-east of the mountain chain. The geological setting with the Jura Mountains and the molasse basin are described, as are the rocks to be found there. Their structures and faults are discussed in detail and their origin and formation are described. The paper presents a number of geological profiles and maps. The methods used to explore these structures are noted, which also indicated the presence of permo-carboniferous troughs in the molasse basin.

Constraining local 3-D models of the saturated-zone, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Barr, G.E.; Shannon, S.A.

1994-01-01

A qualitative three-dimensional analysis of the saturated zone flow system was performed for a 8 km x 8 km region including the potential Yucca Mountain repository site. Certain recognized geologic features of unknown hydraulic properties were introduced to assess the general response of the flow field to these features. Two of these features, the Solitario Canyon fault and the proposed fault in Drill Hole Wash, appear to constrain flow and allow calibration

Nucleation of Waterfalls at Fault Scarps Temporarily Shielded By Alluvial Fan Aggradation.

Science.gov (United States)

Malatesta, L. C.; Lamb, M. P.

2014-12-01

Waterfalls are important components of mountain river systems and they can serve as an agent to transfer tectonic, climatic, or authigenic signals upstream through a catchment. Retreating waterfalls lower the local base level of the adjacent hillslopes, and temporarily increase sediment delivery to the fluvial system. Their creation is often attributed to seismic ruptures, lithological boundaries, or the coalescence of multiple smaller steps. We explore here a mechanism for the nucleation of waterfalls that does not rely on sudden seismic slip but on the build-up of accumulated slip during periods of fault burial by fluvial aggradation. Alluvial fans are common features at the front of mountain ranges bound by normal or thrust faults. Climate change or internal forcing in the mountain catchment modifies the equilibrium slope of alluvial fans. When alluvial fans aggrade, they shield the active fault scarp from fluvial erosion allowing the scarp to grow undisturbed. The scarp may then be exposed when the channel incises into the fan exposing a new bedrock waterfall. We explore this mechanism analytically and using a numerical model for bedrock river incision and sediment deposition. We find that the creation of waterfalls by scarp burial is limited by three distinct timescales: 1) the critical timescale for the scarp to grow to the burial height, 2) the timescale of alluvial re-grading of the fan, and 3) the timescale of the external or internal forcing, such as climate change. The height of the waterfall is controlled by i) the difference in equilibrium alluvial-fan slopes, ii) the ratio of the respective fan and catchment sizes, iii) the catchment wide denudation rate, and iv) the fault slip rate. We test whether an individual waterfall could be produced by alluvial shielding of a scarp, and identify the tectonic, climatic, or authigenic nature of waterfalls using example field sites in the southwest United States.

Post-Pennsylvanian reactivation along the Washita Valley fault, southern Oklahoma

International Nuclear Information System (INIS)

VanArsdale, R.; Ward, C.; Cox, R.

1989-06-01

Surface exposures of faults of the Washita Valley fault (WVF) system in Garvin, Murray, Carter, and Johnston counties of southern Oklahoma were studied to determine if there has been post-Pennsylvanian fault reactivation and to determine if there has been any Quaternary fault movement. This was undertaken through field mapping, by dating alluvium which overlies the faults, and by logging trenches excavated across the WVF. In northern Murray County and southern Garvin County (site A), the WVF displaces Late-Pennsylvanian Oscar Group showing post-Pennsylvanian movement; however, no faulting was observed in 2000 year old alluvium of Wildhorse Creek along strike of the WVF. Three sites (B, C, and D) are located within the Arbuckle Mountains. Faulting of Virgilian age Vanoss Conglomerate and Vanoss Shale reveal post-Virgilian (Late Pennsylvanian) activity along a subsidiary fault in northern Murray County (site B). A 12000 to 15000 year old terrace at this site is unfaulted. Absence of any fault related features in paleosols which overly the WVF along the Washita River (site C) show that the fault has not been active during the last 1570 /+-/ 190 years in southern Murray County. Similarly, absence of any fault related features along Oil Creek (site D) indicates that the WVF has not been active during the last 1810 /+-/ 80 years in northern Carter and Johnston Counties. Faults in the Antlers Sandstone in southern Johnston County (site E) reveal post-Lower Cretaceous reactivation of the WVF. 49 refs., 28 figs., 1 tab

A geologic scenario for catastrophic failure of the Yucca Mountain Nuclear Waste Repository, Nevada

International Nuclear Information System (INIS)

McMackin, M.R.

1993-01-01

A plausible combination of geologic factors leading to failure can be hypothesized for the Yucca Mountain Nuclear Waste Repository. The scenarios is constructed using elementary fault mechanics combined with geologic observations of exhumed faults and published information describing the repository site. The proposed repository site is located in the Basin and Range Province, a region of active crustal deformation demonstrated by widespread seismicity. The Yucca Mountain area has been characterized as tectonically quiet, which in the context of active crustal deformation may indicate the accumulation of the stresses approaching the levels required for fault slip, essentially stick-slip faulting. Simultaneously, dissolution of carbonate rocks in underlying karst aquifers is lowering the bulk strength of the rock that supports the repository site. Rising levels of hydrostatic stress concurrent with a climatically-driven rise in the water table could trigger faulting by decreasing the effective normal stress that currently retards fault slip. Water expelled from collapsing caverns in the underlying carbonate aquifer could migrate upward with sufficient pressure to open existing fractures or create new fractures by hydrofracturing. Water migrating through fractures could reach the repository in sufficient volume to react with heated rock and waste perhaps creating steam explosions that would further enhance fracture permeability. Closure of conduits in the underlying carbonate aquifer could lead to the elevation of the saturated zone above the level of the repository resulting in sustained saturation of radioactive waste in the repository and contamination of through-flowing groundwater

Investigation of the Meers fault in southwestern Oklahoma

International Nuclear Information System (INIS)

Luza, K.V.; Madole, R.F.; Crone, A.J.

1987-08-01

The Meers fault is part of a major system of NW-trending faults that form the boundary between the Wichita Mountains and the Anadarko basin in southwestern Oklahoma. A portion of the Meers fault is exposed at the surface in northern Comanche County and strikes approximately N. 60 0 W. where it offsets Permian conglomerate and shale for at least 26 km. The scarp on the fault is consistently down to the south, with a maximum relief of 5 m near the center of the fault trace. Quaternary stratigraphic relationships and 10 14 C age dates constrain the age of the last movement of the Meers fault. The last movement postdates the Browns Creek Alluvium, late Pleistocene to early Holocene, and predates the East Cache Alluvium, 100 to 800 yr B.P. Fan alluvium, produced by the last fault movement, buried a soil that dates between 1400 and 1100 yr B.P. Two trenches excavated across the scarp near Canyon Creek document the near-surface deformation and provide some general information on recurrence. Trench 1 was excavated in the lower Holocene part of the Browns Creek Alluvium, and trench 2 was excavated in unnamed gravels thought to be upper Pleistocene. Flexing and warping was the dominant mode of deformation that produced the scarp. The stratigraphy in both trenches indicates one surface-faulting event, which implies a lengthy recurrence interval for surface faulting on this part of the fault. Organic-rich material from two samples that postdate the last fault movement yielded 14 C ages between 1600 and 1300 yr B.P. These dates are in excellent agreement with the dates obtained from soils buried by the fault-related fan alluvium

Structural Discordance Between Neogene Detachments and Frontal Sevier Thrusts, Central Mormon Mountains, Southern Nevada

Science.gov (United States)

Wernicke, Brian; Walker, J. Douglas; Beaufait, Mark S.

1985-02-01

Detailed geologic mapping in the Mormon Mountains of southern Nevada provides significant insight into processes of extensional tectonics developed within older compressional orogens. A newly discovered, WSW-directed low-angle normal fault, the Mormon Peak detachment, juxtaposes the highest levels of the frontal most part of the east-vergent, Mesozoic Sevier thrust belt with autochthonous crystalline basement. Palinspastic analysis suggests that the detachment initially dipped 20-25° to the west and cut discordantly across thrust faults. Nearly complete lateral removal of the hanging wall from the area has exposed a 5 km thick longitudinal cross-section through the thrust belt in the footwall, while highly attenuated remnants of the hanging wall (nowhere more than a few hundred meters thick) structurally veneer the range. The present arched configuration of the detachment resulted in part from progressive "domino-style" rotation of a few degrees while it was active, but is largely due to rotation on younger, structurally lower, basement-penetrating normal faults that initiated at high-angle. The geometry and kinematics of normal faulting in the Mormon Mountains suggest that pre-existing thrust planes are not required for the initiation of low-angle normal faults, and even where closely overlapped by extensional tectonism, need not function as a primary control of detachment geometry. Caution must thus be exercised in interpreting low-angle normal faults of uncertain tectonic heritage such as those seen in the COCORP west-central Utah and BIRP's MOIST deep-reflection profiles. Although thrust fault reactivation has reasonably been shown to be the origin of a very few low-angle normal faults, our results indicate that it may not be as fundamental a component of orogenic architecture as it is now widely perceived to be. We conclude that while in many instances thrust fault reactivation may be both a plausible and attractive hypothesis, it may never be assumed.

On Signed Incomplete Cholesky Factorization Preconditioners for Saddle-Point Systems

Czech Academy of Sciences Publication Activity Database

Scott, J.; Tůma, Miroslav

2014-01-01

Roč. 36, č. 6 (2014), A2984-A3010 ISSN 1064-8275 R&D Projects: GA ČR GA13-06684S Grant - others:EPSRC(GB) EP/I013067/1 Program:GA Institutional support: RVO:67985807 Keywords : sparse matrices * sparse linear systems * indefinite symmetric systems * saddle-point systems * iterative solvers * preconditioning * incomplete Cholesky factorization Subject RIV: BA - General Mathematics Impact factor: 1.854, year: 2014

Basaltic volcanic episodes of the Yucca Mountain region

International Nuclear Information System (INIS)

Crowe, B.M.

1990-01-01

The purpose of this paper is to summarize briefly the distribution and geologic characteristics of basaltic volcanism in the Yucca Mountain region during the last 10--12 Ma. This interval largely postdates the major period of silicic volcanism and coincides with and postdates the timing of major extensional faulting in the region. Field and geochronologic data for the basaltic rocks define two distinct episodes. The patterns in the volume and spatial distribution of these basaltic volcanic episodes in the central and southern part of the SNVF are used as a basis for forecasting potential future volcanic activity in vicinity of Yucca Mountain. 33 refs., 2 figs

Geology of the central Mineral Mountains, Beaver County, Utah

Energy Technology Data Exchange (ETDEWEB)

Sibbett, B.S.; Nielson, D.L.

1980-03-01

The Mineral Mountains are located in Beaver and Millard Counties, southwestern Utah. The range is a horst located in the transition zone between the Basin and Range and Colorado Plateau geologic provinces. A multiple-phase Tertiary pluton forms most of the range, with Paleozoic rocks exposed on the north and south and Precambrian metamorphic rocks on the west in the Roosevelt Hot Springs KGRA (Known Geothermal Resource Area). Precambrian banded gneiss and Cambrian carbonate rocks have been intruded by foliated granodioritic to monzonitic rocks of uncertain age. The Tertiary pluton consists of six major phases of quartz monzonitic to leucocratic granitic rocks, two diorite stocks, and several more mafic units that form dikes. During uplift of the mountain block, overlying rocks and the upper part of the pluton were partially removed by denudation faulting to the west. The interplay of these low-angle faults and younger northerly trending Basin and Range faults is responsible for the structural control of the Roosevelt Hot Springs geothermal system. The structural complexity of the Roosevelt Hot Springs KGRA is unique within the range, although the same tectonic style continues throughout the range. During the Quaternary, rhyolite volcanism was active in the central part of the range and basaltic volcanism occurred in the northern portion of the map area. The heat source for the geothermal system is probably related to the Quaternary rhyolite volcanic activity.

Mountain building in the central Andes

Science.gov (United States)

Kono, Masaru; Fukao, Yoshio; Yamamoto, Akihiko

1989-04-01

The Central Andes is the middle part of the Andean chain between about 13°S and 27°S, characterized by the parallel running high mountain chains (the Western and Eastern Cordilleras) at the edges of high plateaus with a height of about 4000 m and a width of 200 to 450 km (the Altiplano-Puna). From the examination of geophysical and geological data in this area, including earthquakes, deformation, gravity anomaly, volcanism, uplift history, and plate motion, we conclude that the continued plate subduction with domination of compressive stress over the entire arc system is the main cause of the tectonic style of the Central Andes. We propose that the present cycle of mountain building has continued in the Cenozoic with the most active phase since the Miocene, and that the present subduction angle (30°) is not typical in that period but that subduction with more shallowly dipping oceanic lithosphere has prevailed at least since the Miocene, because of the young and buoyant slab involved. This situation is responsible for the production of a broad zone of partial melt in the mantle above the descending slab. Addition of volcanic materials was not restricted to the western edge (where active volcanoes of the Western Cordillera exist) but extended to the western and central portion of the Altiplano-Puna. The western half of the Central Andes is essentially isostatic because the heat transferred with the volcanic activities softened the crust there. In the eastern edge, the thermal effect is small, and the crust is strongly pushed by the westward moving South American plate. This caused the shortening of crustal blocks due to reverse faulting and folding in the Eastern Cordillera and Amazonian foreland. The magmatism and crustal accretion are dominant at the western end of the mountain system and decrease eastward, while the compression and consequent crustal shortening are strongest at the eastern end and wane toward west. These two processes are superposed between

A tunnel runs through it: an inside view of the Tualatin Mountains, Oregon

Science.gov (United States)

Walsh, Ken; Peterson, Gary L.; Beeson, Marvin H.; Wells, Ray E.; Fleck, Robert J.; Evarts, Russell C.; Duvall, Alison; Blakely, Richard J.; Burns, Scott

2011-01-01

The Tualatin Mountains form a northwest-striking ridge about 350 m high that separates Portland, Oregon, from the cities of the Tualatin Valley to the west. Known informally as the Portland Hills, the ridge is a late Cenozoic anticline, bounded by reverse faults that dip toward the anticlinal axis. The anticline is a broad, open fold consisting chiefly of Miocene Columbia River Basalt Group, with remnants of Miocene-Pliocene Troutdale Formation and Pleistocene basalt of the Boring Volcanic Field on the flanks of the anticline. Anticlinal structures similar to the Tualatin Mountains are characteristic of the northern Willamette Valley, where the structures accommodate margin-parallel shortening of the Cascadia fore arc. Global Positioning System (GPS) results indicate that the shortening is due to the northward motion of Oregon at several millimeters per year with respect to stable North America. Some of the uplifts may contain active faults, but the structures are poorly exposed and are overlain by thick Pleistocene loess and Missoula flood deposits. Between 1993 and 1998, construction of the 3-mile-long (4500-m-long) TriMet MAX Light Rail tunnel through the Tualatin Mountains provided an unusual opportunity to investigate the geological structure and history of the Tualatin Mountains. This report is a collaborative effort among the tunnel geologists and the U.S. Geological Survey (USGS) to document the geologic story and quantify late Cenozoic and Quaternary deformation rates of the Tualatin Mountains.

Self-constrained inversion of microgravity data along a segment of the Irpinia fault

Science.gov (United States)

Lo Re, Davide; Florio, Giovanni; Ferranti, Luigi; Ialongo, Simone; Castiello, Gabriella

2016-01-01

A microgravity survey was completed to precisely locate and better characterize the near-surface geometry of a recent fault with small throw in a mountainous area in the Southern Apennines (Italy). The site is on a segment of the Irpinia fault, which is the source of the M6.9 1980 earthquake. This fault cuts a few meter of Mesozoic carbonate bedrock and its younger, mostly Holocene continental deposits cover. The amplitude of the complete Bouguer anomaly along two profiles across the fault is about 50 μGal. The data were analyzed and interpreted according to a self-constrained strategy, where some rapid estimation of source parameters was later used as constraint for the inversion. The fault has been clearly identified and localized in its horizontal position and depth. Interesting features in the overburden have been identified and their interpretation has allowed us to estimate the fault slip-rate, which is consistent with independent geological estimates.

Exhumation of the Black Mountains in Death Valley, California, with new thermochronometric data from the Badwater Turtleback

Science.gov (United States)

Sizemore, T. M.; Cemen, I.; Wielicki, M. M.; Stockli, D. F.; Heizler, M. T.; Lutz, B. M.

2017-12-01

The Black Mountains, in Death Valley, California, are one of the key areas to better understand Basin and Range extension because they contain Cenozoic igneous and sedimentary rocks overlying mid- to deep-crustal, 1.74 Ga basement gneiss with abundant fault striations, large-scale extensional folds, and tectonite fabrics containing top-to-the-northwest shear-sense indicators. These rocks make up the footwall of three prominent, high-relief "turtleback" fault surfaces in the western flank of the Black Mountains, which are thought to have accommodated a significant amount of strain in the Death Valley area. It is unknown whether the missing Paleozoic and Mesozoic strata in the Black Mountains were removed in association with high-angle faulting, or along a continuous detachment surface with a rolling-hinge style of faulting as the hanging wall moved to the west, now forming the Panamint Range. The turtlebacks play an important role in resolving this question because they are commonly cited as containing conflicting evidence of both hypotheses. To provide insight into this problem, we are building an exhumation model across the Black Mountains using previously published thermochronometric data as well as new transect-based (U-Th)/He and Ar-Ar thermochronology and U-Pb geochronology for the Badwater turtleback. The model will provide a four-dimensional view of the exhumation history of the Black Mountains, to serve as evidence for either of the two previously mentioned hypotheses, or possibly some other style of exhumation. Additionally, we will compare the exhumation history of the Black Mountains to that of the Panamint Range using previously published data and interpretations. Our preliminary zircon U-Pb data suggest a crystallization age for the gneissic rocks on the Badwater turtleback of 1.74 Ga (207Pb/206Pb, 2σ error=31.8 Ma, n=6) with two younger populations at 1.46 Ga (207Pb/206Pb, 2σ error=51.8 Ma, n=3) and 79.6 Ma (206Pb/238U, 2σ error=10.0 Ma, n=2

Regional anesthesia in transurethral resection of prostate (TURP surgery: A comparative study between saddle block and subarachnoid block

Directory of Open Access Journals (Sweden)

Susmita Bhattacharyya

2015-01-01

Full Text Available Background: Spinal anesthesia is the technique of choice in transurethral resection of prostate (TURP. The major complication of spinal technique is risk of hypotension. Saddle block paralyzed pelvic muscles and sacral nerve roots and hemodynamic derangement is less. Aims and objectives: To compare the hemodynamic changes and adequate surgical condition between saddle block and subarachnoid block for TURP. Material and methods: Ninety patients of aged between 50 to 70 years of ASA-PS I, II scheduled for TURP were randomly allocated into 2 groups of 45 in each group. Group A patients were received spinal (2 ml of hyperbaric bupivacaine and Group B were received saddle block (2 ml of hyperbaric bupivacaine. Baseline systolic, diastolic and mean arterial pressure, heart rate, oxygen saturation were recorded and measured subsequently. The height of block was noted in both groups. Hypotension was corrected by administration of phenylephrine 50 mcg bolus and total requirement of vasopressor was noted. Complications (volume overload, TURP syndrome etc. were noted. Results: Incidence of hypotension and vasopressor requirement was less (P < 0.01 in Gr B patients.Adequate surgical condition was achieved in both groups. There was no incidence of volume overload, TURP syndrome, and bladder perforation. Conclusion: TURP can be safely performed under saddle block without hypotension and less vasopressor requirement.

Non-invasive Investigation and Management of Aortic Saddle Embolus in a 7-Month-Old Infant

International Nuclear Information System (INIS)

O'Connell, Martin J.; Duff, Desmond F.; Hayes, Roisin M.

2002-01-01

There are few reports in the literature on the ultrasound appearance of aortic saddle embolus, and none relating to small children. This unusual condition is usually diagnosed angiographically. The purpose of this report is to show how effectively high-frequency ultrasound can identify a saddle embolus with its associated collateral circulation in a young child, and to demonstrate its usefulness in monitoring the efficacy of treatment. In this case the embolus occurred as a complication of parvovirus B19 myocarditis and was diagnosed and followed up entirely by ultrasound examination,with no invasive procedure performed. The early development of an extensive collateral circulation prevented distal tissue necrosis and allowed a conservative approach to management

Perspective view, Landsat overlay San Andreas Fault, Palmdale, California

Science.gov (United States)

2000-01-01

The prominent linear feature straight down the center of this perspective view is the San Andreas Fault. This segment of the fault lies near the city of Palmdale, California (the flat area in the right half of the image) about 60 kilometers (37 miles) north 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. The Lake Palmdale Reservoir, approximately 1.5 kilometers (0.9 miles) across, sits in the topographic depression created by past movement along the fault. Highway 14 is the prominent linear feature starting at the lower left edge of the image and continuing along the far side of the reservoir. The patterns of residential and agricultural development around Palmdale are seen in the Landsat imagery in the right half of the image. SRTM topographic data will be used by geologists studying fault dynamics and landforms resulting from active tectonics.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

Geology of the Nine Canyon Map Area

International Nuclear Information System (INIS)

Jones, M.G.; Landon, R.D.

1978-09-01

The basalt stratigraphy and structure of a 175-square kilometer area (the Nine Canyon Map Area) along the southern margin of the Pasco Basin have been studied to help assess the feasibility of a nuclear waste terminal storage facility. Detailed mapping shows that uplift of the Horse Heaven Hills began prior to extrusion of the Priest Rapids Member of the Wanapum Basalt, Columbia River Basalt Group. Both the Pomoma and the Elephant Mountain members (Saddle Mountains Basalt, Columbia River Basalt Group) are wide-spread throughout the basin, but thin considerably along the Horse Heaven Hills in the vicinity of Wallula Gap. The Ice Harbor Member is present only along the northern margin of the map area and possibly occupies a paleo-channel. The Rattlesnake Hills-Wallula Gap Lineament trends north 60 degrees west and intersects the older Horse Heaven Hills anticline in Wallula Gap. Four faults of short length and small vertical displacement are located along this structure. Within the map area, the intensity of folding increases, and the style of faulting changes from normal to reverse with proximity to the Wallula Gap area. No evidence for Quaternary deformation was found

Strike-slip faults offshore southern Taiwan: implications for the oblique arc-continent collision processes

Science.gov (United States)

Fuh, Shi-Chie; Liu, Char-Shine; Lundberg, Neil; Reed, Donald L.

1997-06-01

Taiwan is the site of present-day oblique arc-continent collision between the Luzon arc of the Philippine Sea plate and the Chinese continental margin. The major structural pattern revealed from marine geophysical studies in the area offshore southern Taiwan is that of a doubly-vergent orogenic belt, bounded by significant zones of thrusting on the west and east of the submarine accretionary wedge. Due to the oblique collision process, strike-slip faults could play an important role in this convergent domain. Topographic lineaments revealed from new digital bathymetry data and seismic reflection profiles confirm the existence of three sets of strike-slip faults in the collision-subduction zone offshore southern Taiwan: the N-S-trending left-lateral strike-slip faults within the Luzon volcanic arc, the NE-SW-trending right-lateral strike-slip faults across the accretionary wedge, and the NNE-SSW-trending left-lateral strike-slip faults lie in the frontal portion of the accretionary wedge. These strike-slip faults overprint pre-existing folds and thrusts and may convert into oblique thrusts or thrusts as the forearc blocks accrete to the mountain belt. A bookshelf rotation model is used to explain the observed geometrical relationships of these strike-slip fault systems. Based on this model, the counter-clockwise rotation of the forearc blocks in the area offshore southern Taiwan could have caused extrusion of the accretionary wedge material into the forearc basin. The originally continuous forearc basin is thus deformed into several closed and separate proto-collisional basins such as the Southern Longitudinal Trough and Taitung Trough. A tectonic evolution model which emphasizes on the development of various structures at different stages of the oblique arc-continent collision for the Taiwan mountain belt is proposed.

Limiting Accuracy of Segregated Solution Methods for Nonsymmetric Saddle Point Problems

Czech Academy of Sciences Publication Activity Database

Jiránek, P.; Rozložník, Miroslav

Roc. 215, c. 1 (2008), s. 28-37 ISSN 0377-0427 R&D Projects: GA MŠk 1M0554; GA AV ČR 1ET400300415 Institutional research plan: CEZ:AV0Z10300504 Keywords : saddle point problems * Schur complement reduction method * null-space projection method * rounding error analysis Subject RIV: BA - General Mathematics Impact factor: 1.048, year: 2008

Saddle-shaped reticulate Nummulites from Early Oligocene rocks of Khari area, SW Kutch, India

Science.gov (United States)

Sengupta, S.; Sarkar, Sampa; Mukhopadhyay, S.

2011-04-01

Saddle-shaped reticulate Nummulites from the Early Oligocene rocks of Khari area, SW Kutch, India is reported here for the first time. Unusual shape of this Nummulites is due to the curved nature of the coiling plane, indicating space constrained postembryonic test growth. With regular development of chambers, septa and septal filaments, the saddle-shaped Nummulites constitutes the third morphotype of N. cf. fichteli Michelotti form A. Other morphotypes of the species reported earlier include inflated lenticular and conical tests. Multiple morphotypes of N. cf. fichteli form A indicates varied test growth in response to substrate conditions. Morphological variability exhibited by N. cf. fichteli form A from Kutch and some Early Oligocene reticulate Nummulites from the Far East are comparable. This faunal suite is morphologically distinct from the contemporary reticulate Nummulites of the European localities.

Large N saddle formulation of quadratic building block theories

International Nuclear Information System (INIS)

Halpern, M.B.

1980-01-01

I develop a large N saddle point formulation for the broad class of 'theories of quadratic building blocks'. Such theories are those on which the sums over internal indices are contained in quadratic building blocks, e.g. PHI 2 = Σsup(N)sub(a-1)PHi sup(a)sup(a). The formulation applies as well to fermions, derivative coupling and non-polynomial interactions. In a related development, closed Schwinger-Dyson equations for Green functions of the building blocks are derived and solved for large N. (orig.)

Saddle-points of a two dimensional random lattice theory

International Nuclear Information System (INIS)

Pertermann, D.

1985-07-01

A two dimensional random lattice theory with a free massless scalar field is considered. We analyse the field theoretic generating functional for any given choice of positions of the lattice sites. Asking for saddle-points of this generating functional with respect to the positions we find the hexagonal lattice and a triangulated version of the hypercubic lattice as candidates. The investigation of the neighbourhood of a single lattice site yields triangulated rectangles and regular polygons extremizing the above generating functional on the local level. (author)

Method development and strategy for the characterization of complexly faulted and fractured rhyolitic tuffs, Yucca Mountain, Nevada, USA

International Nuclear Information System (INIS)

Karasaki, K.; Galloway, D.

1990-10-01

Field experimental and analytical methods development is underway to define the hydraulic and transport properties of a thick saturated zone that underlies the planned high-level nuclear waste repository at Yucca Mountain, Nevada. The characterization strategy for the highly heterogeneous hydrology is that of hypothesis testing and confidence building. Three test wells, the UE-25c-holes, have been drilled and preliminary data have been collected. Hydro-mechanical analyses indicate formation fluid at depth is hydraulically connected to the water table. Preliminary hydraulic tests indicate highly localized, fracture-controlled transmissivity. Cross-hole seismic tomography is planned to assess the inter-borehole structure of fractures and faults. Multi-level cross-hole hydraulic interference and tracer tests are planned using up to 5 packed-off zones in each of the c-holes to assess the hydraulic conductivity and transport structure in a crude tomographic fashion. An equivalent discontinuum model conditioned with the observed hydraulic measurements will be applied to interpret the hydraulic test responses. As an approach to the scale problem the tests will be designed and analyzed to examine the hypothesis that the flow system may be represented by fractal geometry. 12 refs., 4 figs

Post-Eocene tectonics of the Central Taurus Mountains

Directory of Open Access Journals (Sweden)

Ergün AKAY

1988-06-01

Full Text Available In post-Eocene time, the Central Taurus mountains have been subjected to four episodes of compression in probably Upper Eocene — Lower Oligocene, Langhian, Upper Tortonian, and Upper Pliocene to recent times. In the Upper Eocene — Lower Oligocene compressional period, Ecemiş, and Beyşehir conjugate faults which have both vertical and lateral components have been formed after an N - S compression. In the Langhian compression period, the Lycian nappes were emplaced from the NW to SE and this tectonic movement has also effected the Antalya and the Adana Miocene basins. In the Upper Tortonian compression period, firstly a WSW-ENE compression has resulted in the formation of Aksu thrust, Kırkkavak oblique reverse fault, Köprüçay syncline, Beşkonak anticline, Radyoring anticline, Taşağıl syncline and Kargı reverse faults. In this period a later phase of N — S compression has formed Çakallar folds, Gökçeler normal fault, the smooth anticline in Mut Karaman and the syncline in Ulukışla. In the latest compressional period from Upper Pliocene to recent, first on E — W compression which can be recognized by some mesoscopic faults has been developed and later a N — S compression resulted in the formation of the active faults on Ecemiş and Gökçeler faults, and the Antalya bay graben.

Geologyy of the Yucca Mountain Site Area, Southwestern Nevada, Chapter in Stuckless, J.S., ED., Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste (Volume 1)

Energy Technology Data Exchange (ETDEWEB)

W.R. Keefer; J.W. Whitney; D.C. Buesch

2006-09-25

Yucca Mountain in southwestern Nevada is a prominent, irregularly shaped upland formed by a thick apron of Miocene pyroclastic-flow and fallout tephra deposits, with minor lava flows, that was segmented by through-going, large-displacement normal faults into a series of north-trending, eastwardly tilted structural blocks. The principal volcanic-rock units are the Tiva Canyon and Topopah Spring Tuffs of the Paintbrush Group, which consist of volumetrically large eruptive sequences derived from compositionally distinct magma bodies in the nearby southwestern Nevada volcanic field, and are classic examples of a magmatic zonation characterized by an upper crystal-rich (> 10% crystal fragments) member, a more voluminous lower crystal-poor (< 5% crystal fragments) member, and an intervening thin transition zone. Rocks within the crystal-poor member of the Topopah Spring Tuff, lying some 280 m below the crest of Yucca Mountain, constitute the proposed host rock to be excavated for the storage of high-level radioactive wastes. Separation of the tuffaceous rock formations into subunits that allow for detailed mapping and structural interpretations is based on macroscopic features, most importantly the relative abundance of lithophysae and the degree of welding. The latter feature, varying from nonwelded through partly and moderately welded to densely welded, exerts a strong control on matrix porosities and other rock properties that provide essential criteria for distinguishing hydrogeologic and thermal-mechanical units, which are of major interest in evaluating the suitability of Yucca Mountain to host a safe and permanent geologic repository for waste storage. A thick and varied sequence of surficial deposits mantle large parts of the Yucca Mountain site area. Mapping of these deposits and associated soils in exposures and in the walls of trenches excavated across buried faults provides evidence for multiple surface-rupturing events along all of the major faults during

The role of the Anaxagoras Mountain in the Miocene to Recent tectonic evolution of the eastern Mediterranean

Science.gov (United States)

Colbourne, Mark; Hall, Jeremy; Aksu, Ali; Çifçi, Günay

2014-05-01

The Anaximander Mountains are one of the many enigmatic structures situated along the morphologically and structurally complicated junction between the Hellenic and Cyprus Arcs, in the eastern Mediterranean. Interpretation of ~750 km of marine multi-channel seismic reflection data show that the present day Anaximander Mountains underwent several distinct phases of tectonic activity since Miocene. During the mid-late Miocene, a protracted, contractional tectonic regime produced the east-west trending, south-verging fold-thrust belt observed in the area. The Messinian was a period of relatively low tectonic activity, and is marked by the deposition of an evaporite layer. This phase lasted until the latest Miocene - earliest Pliocene, when a major erosional event associated with the Messinian salinity crisis occurred. Beginning in the early-mid Pliocene-Quaternary a transpressional and rotational tectonic regime prevailed over the area. The Anaximander Mountain (sensu stricto) and Anaximenes Mountain developed in the Pliocene-Quaternary associated with the reactivation, uplift and rotation of a linked, thick skinned pre-Messinian imbricate thrust fan. Back thrusting in the region accentuated the morphology of these mountains. The Anaxagoras Mountain differs both lithologically and morphologically from the Anaximander Mountain (sensu stricto) and the Anaximenes Mountain. It is probably developed associated with the emplacement of the ophiolitic Antalya Nappe Complex. Faulting in the Anaxagoras region is characterized by southwest striking thrust and/or oblique thrust faults. Due to the similarities in morphology between the Isparta Angle of southwestern Turkey and the Anaximander Mountains (sensu lato), it is hypothesized that the tectonic evolution of the two regions are similar in nature. The Anaximander Mountains (sensu lato) can thus be considered the offshore replication of the Isparta Angle, produced by similar mechanisms, but being of a younger age.

Modeling unsaturated-zone flow at Rainier Mesa as a possible analog for a future Yucca Mountain

International Nuclear Information System (INIS)

Gauthier, J.H.

1998-01-01

Rainier Mesa is structurally similar to Yucca Mountain, and receives precipitation similar to the estimated long-term average for Yucca Mountain. Tunnels through the unsaturated zone at Rainier Mesa have encountered perched water and, after the perched water was drained, flow in fractures and faults. Although flow observations have been primarily qualitative, Rainier Mesa hydrology is a potential analog for Yucca Mountain hydrology in a wetter climate. In this paper, a groundwater flow model that has been used in the performance assessment of Yucca Mountain--the weeps model--is applied to Rainier Mesa. The intent is to gain insight in both Rainier Mesa and the weeps flow model

The Black Mountains turtlebacks: Rosetta stones of Death Valley tectonics

Science.gov (United States)

Miller, Marli B.; Pavlis, Terry L.

2005-12-01

The Black Mountains turtlebacks expose mid-crustal rock along the western front of the Black Mountains. As such, they provide keys to understanding the Tertiary structural evolution of Death Valley, and because of the outstanding rock exposure, they also provide valuable natural laboratories for observing structural processes. There are three turtlebacks: the Badwater turtleback in the north, the Copper Canyon turtleback, and the Mormon Point turtleback in the south. Although important differences exist among them, each turtleback displays a doubly plunging antiformal core of metamorphic and igneous rock and a brittle fault contact to the northwest that is structurally overlain by Miocene-Pleistocene volcanic and/or sedimentary rock. The turtleback cores contain mylonitic rocks that record an early period of top-southeastward directed shear followed by top-northwestward directed shear. The earlier formed mylonites are cut by, and locally appear concurrent with, 55-61 Ma pegmatite. We interpret these fabrics as related to large-scale, basement-involved thrust faults at the turtlebacks, now preserved as areally-extensive, metamorphosed, basement over younger-cover contacts. The younger, and far more pervasive, mylonites record late Tertiary extensional unroofing of the turtleback footwalls from mid-crustal depths. Available geochronology suggests that they cooled through 300 °C at different times: 13 Ma at Badwater; 6 Ma at Copper Canyon; 8 Ma at Mormon Point. At Mormon Point and Copper Canyon turtlebacks these dates record cooling of the metamorphic assemblages from beneath the floor of an ˜ 11 Ma Tertiary plutonic complex. Collectively these relationships suggest that the turtlebacks record initiation of ductile extension before ˜ 14 Ma followed by injection of a large plutonic complex along the ductile shear zone. Ductile deformation continued during extensional uplift until the rocks cooled below temperatures for crystal plastic deformation by 6-8 Ma

Computation of saddle-type slow manifolds using iterative methods

DEFF Research Database (Denmark)

Kristiansen, Kristian Uldall

2015-01-01

with respect to , appropriate estimates are directly attainable using the method of this paper. The method is applied to several examples, including a model for a pair of neurons coupled by reciprocal inhibition with two slow and two fast variables, and the computation of homoclinic connections in the Fitz......This paper presents an alternative approach for the computation of trajectory segments on slow manifolds of saddle type. This approach is based on iterative methods rather than collocation-type methods. Compared to collocation methods, which require mesh refinements to ensure uniform convergence...

Three-Dimensional Growth of Flexural Slip Fault-Bend and Fault-Propagation Folds and Their Geomorphic Expression

Directory of Open Access Journals (Sweden)

Asdrúbal Bernal

2018-03-01

Full Text Available The three-dimensional growth of fault-related folds is known to be an important process during the development of compressive mountain belts. However, comparatively little is known concerning the manner in which fold growth is expressed in topographic relief and local drainage networks. Here we report results from a coupled kinematic and surface process model of fault-related folding. We consider flexural slip fault-bend and fault-propagation folds that grow in both the transport and strike directions, linked to a surface process model that includes bedrock channel development and hillslope diffusion. We investigate various modes of fold growth under identical surface process conditions and critically analyse their geomorphic expression. Fold growth results in the development of steep forelimbs and gentler, wider backlimbs resulting in asymmetric drainage basin development (smaller basins on forelimbs, larger basins on backlimbs. However, topographies developed above fault-propagation folds are more symmetric than those developed above fault-bend folds as a result of their different forelimb kinematics. In addition, the surface expression of fault-bend and fault-propagation folds depends both on the slip distribution along the fault and on the style of fold growth. When along-strike plunge is a result of slip events with gently decreasing slip towards the fault tips (with or without lateral propagation, large plunge-panel drainage networks are developed at the expense of backpanel (transport-opposing and forepanel (transport-facing drainage basins. In contrast, if the fold grows as a result of slip events with similar displacements along strike, plunge-panel drainage networks are poorly developed (or are transient features of early fold growth and restricted to lateral fold terminations, particularly when the number of propagation events is small. The absence of large-scale plunge-panel drainage networks in natural examples suggests that the

Saddle-splay screening and chiral symmetry breaking in toroidal nematics

OpenAIRE

Koning, Vinzenz; van Zuiden, Benjamin C.; Kamien, Randall D.; Vitelli, Vincenzo

2013-01-01

We present a theoretical study of director fields in toroidal geometries with degenerate planar boundary conditions. We find spontaneous chirality: despite the achiral nature of nematics the director configuration show a handedness if the toroid is thick enough. In the chiral state the director field displays a double twist, whereas in the achiral state there is only bend deformation. The critical thickness increases as the difference between the twist and saddle-splay moduli grows. A positiv...

San Andreas Fault in the Carrizo Plain

Science.gov (United States)

2000-01-01

The 1,200-kilometer (800-mile)San Andreas is the longest fault in California and one of the longest in North America. This perspective view of a portion of the fault was generated using data from the Shuttle Radar Topography Mission (SRTM), which flew on NASA's Space Shuttle last February, and an enhanced, true-color Landsat satellite image. The view shown looks southeast along the San Andreas where it cuts along the base of the mountains in the Temblor Range near Bakersfield. The fault is the distinctively linear feature to the right of the mountains. To the left of the range is a portion of the agriculturally rich San Joaquin Valley. In the background is the snow-capped peak of Mt. Pinos at an elevation of 2,692 meters (8,831 feet). The complex topography in the area is some of the most spectacular along the course of the fault. To the right of the fault is the famous Carrizo Plain. Dry conditions on the plain have helped preserve the surface trace of the fault, which is scrutinized by both amateur and professional geologists. In 1857, one of the largest earthquakes ever recorded in the United States occurred just north of the Carrizo Plain. With an estimated magnitude of 8.0, the quake severely shook buildings in Los Angeles, caused significant surface rupture along a 350-kilometer (220-mile) segment of the fault, and was felt as far away as Las Vegas, Nev. This portion of the San Andreas is an important area of study for seismologists. For visualization purposes, topographic heights displayed in this image are exaggerated two times.The elevation data used in this image was acquired by 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 Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60

Structural characteristics and implication on tectonic evolution of the Daerbute strike-slip fault in West Junggar area, NW China

Science.gov (United States)

Wu, Kongyou; Pei, Yangwen; Li, Tianran; Wang, Xulong; Liu, Yin; Liu, Bo; Ma, Chao; Hong, Mei

2018-03-01

The Daerbute fault zone, located in the northwestern margin of the Junggar basin, in the Central Asian Orogenic Belt, is a regional strike-slip fault with a length of 400 km. The NE-SW trending Daerbute fault zone presents a distinct linear trend in plain view, cutting through both the Zair Mountain and the Hala'alate Mountain. Because of the intense contraction and shearing, the rocks within the fault zone experienced high degree of cataclasis, schistosity, and mylonization, resulting in rocks that are easily eroded to form a valley with a width of 300-500 m and a depth of 50-100 m after weathering and erosion. The well-exposed outcrops along the Daerbute fault zone present sub-horizontal striations and sub-vertical fault steps, indicating sub-horizontal shearing along the observed fault planes. Flower structures and horizontal drag folds are also observed in both the well-exposed outcrops and high-resolution satellite images. The distribution of accommodating strike-slip splay faults, e.g., the 973-pluton fault and the Great Jurassic Trough fault, are in accordance with the Riedel model of simple shear. The seismic and time-frequency electromagnetic (TFEM) sections also demonstrate the typical strike-slip characteristics of the Daerbute fault zone. Based on detailed field observations of well-exposed outcrops and seismic sections, the Daerbute fault can be subdivided into two segments: the western segment presents multiple fault cores and damage zones, whereas the eastern segment only presents a single fault core, in which the rocks experienced a higher degree of rock cataclasis, schistosity, and mylonization. In the central overlapping portion between the two segments, the sediments within the fault zone are primarily reddish sandstones, conglomerates, and some mudstones, of which the palynological tests suggest middle Permian as the timing of deposition. The deformation timing of the Daerbute fault was estimated by integrating the depocenters' basinward

Major results of gravity and magnetic studies at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Oliver, H.W.; Ponce, D.A.; Sikora, R.F.

1991-01-01

About 4,000 gravity stations have been obtained at Yucca Mountain and vicinity since the beginning of radioactive-waste studies there in 1978. These data have been integrated with data from about 29,000 stations previously obtained in the surrounding region to produce a series of Bouguer and isostatic-residual-gravity maps of the Nevada Test Site and southeastern Nevada. Yucca Mountain is characterized by a WNW-dipping gravity gradient whereby residual values of -10 mGal along the east edge of Yucca Mountain decrease to about -38 mGal over Crater Flat. Using these gravity data, two-dimensional modeling predicted the depth to pre-Cenozoic rocks near the proposed repository to be about 1,220±150 m, an estimate that was subsequently confirmed by drilling to be 1,244 m. Three-dimensional modeling of the gravity low over Crater Flat indicates the thickness of Cenozoic volcanic rocks and alluvial cover to be about 3,000 m. Gravity interpretations also identified the Silent Canyon caldera before geologic mapping of Pahute Mesa and provided an estimate of the thickness of the volcanic section there of nearly 5 km. Considerable aeromagnetic coverage of southwestern Nevada was obtained in 1978-79 to help characterize Yucca Mountain and vicinity. One significant result is the discovery of a series of circular magnetic anomalies in Crater Flat and the northern Amargosa Desert that suggest the presence of buried volcanic centers there. If this interpretation is confirmed by drilling, the magnetic data can be used to help estimate the total volume of buried volcanic rocks, which, along with radiometric dating, could help provide a better prediction of future volcanism. Elongate magnetic highs and associated lows over Yucca Mountain correlate with mapped faults, some of which are only partially exposed. Thus, the data provide information on the extent and continuity of these faults

Neotectonic inversion of the Hindu Kush-Pamir mountain region

Science.gov (United States)

Ruleman, C.A.

2011-01-01

The Hindu Kush-Pamir region of southern Asia is one of Earth's most rapidly deforming regions and it is poorly understood. This study develops a kinematic model based on active faulting in this part of the Trans-Himalayan orogenic belt. Previous studies have described north-verging thrust faults and some strike-slip faults, reflected in the northward-convex geomorphologic and structural grain of the Pamir Mountains. However, this structural analysis suggests that contemporary tectonics are changing the style of deformation from north-verging thrusts formed during the initial contraction of the Himalayan orogeny to south-verging thrusts and a series of northwest-trending, dextral strike-slip faults in the modern transpressional regime. These northwest-trending fault zones are linked to the major right-lateral Karakoram fault, located to the east, as synthetic, conjugate shears that form a right-stepping en echelon pattern. Northwest-trending lineaments with dextral displacements extend continuously westward across the Hindu Kush-Pamir region indicating a pattern of systematic shearing of multiple blocks to the northwest as the deformation effects from Indian plate collision expands to the north-northwest. Locally, east-northeast- and northwest-trending faults display sinistral and dextral displacement, respectively, yielding conjugate shear pairs developed in a northwest-southeast compressional stress field. Geodetic measurements and focal mechanisms from historical seismicity support these surficial, tectono-morphic observations. The conjugate shear pairs may be structurally linked subsidiary faults and co-seismically slip during single large magnitude (> M7) earthquakes that occur on major south-verging thrust faults. This kinematic model provides a potential context for prehistoric, historic, and future patterns of faulting and earthquakes.

Large-scale hydraulic structure of a seismogenic fault at 10 km depth (Gole Larghe Fault Zone, Italian Southern Alps)

Science.gov (United States)

Bistacchi, Andrea; Di Toro, Giulio; Smith, Steve; Mittempergher, Silvia; Garofalo, Paolo

2014-05-01

The definition of hydraulic properties of fault zones is a major issue in structural geology, seismology, and in several applications (hydrocarbons, hydrogeology, CO2 sequestration, etc.). The permeability of fault rocks can be measured in laboratory experiments, but its upscaling to large-scale structures is not straightforward. For instance, typical permeability of fine-grained fault rock samples is in the 10-18-10-20 m2 range, but, according to seismological estimates, the large-scale permeability of active fault zones can be as high as 10-10 m2. Solving this issue is difficult because in-situ measurements of large-scale permeability have been carried out just at relatively shallow depths - mainly in oil wells and exceptionally in active tectonic settings (e.g. SAFOD at 3 km), whilst deeper experiments have been performed only in the stable continental crust (e.g. KTB at 9 km). In this study, we apply discrete fracture-network (DFN) modelling techniques developed for shallow aquifers (mainly in nuclear waste storage projects like Yucca Mountain) and in the oil industry, in order to model the hydraulic structure of the Gole Larghe Fault Zone (GLFZ, Italian Southern Alps). This fault, now exposed in world-class glacier-polished outcrops, has been exhumed from ca. 8 km, where it was characterized by a well-documented seismic activity, but also by hydrous fluid flow evidenced by alteration halos and precipitation of hydrothermal minerals in veins and along cataclasites. The GLFZ does not show a classical seal structure that in other fault zones corresponds to a core zone characterized by fine-grained fault rocks. However, permeability is heterogeneous and the permeability tensor is strongly anisotropic due to fracture preferential orientation. We will show with numerical experiments that this hydraulic structure results in a channelized fluid flow (which is consistent with the observed hydrothermal alteration pattern). This results in a counterintuitive situation

Differential Extension, Displacement Transfer, and the South to North Decrease in Displacement on the Furnace Creek - Fish Lake Valley Fault System, Western Great Basin.

Science.gov (United States)

Katopody, D. T.; Oldow, J. S.

2015-12-01

The northwest-striking Furnace Creek - Fish Lake Valley (FC-FLV) fault system stretches for >250 km from southeastern California to western Nevada, forms the eastern boundary of the northern segment of the Eastern California Shear Zone, and has contemporary displacement. The FC-FLV fault system initiated in the mid-Miocene (10-12 Ma) and shows a south to north decrease in displacement from a maximum of 75-100 km to less than 10 km. Coeval elongation by extension on north-northeast striking faults within the adjoining blocks to the FC-FLV fault both supply and remove cumulative displacement measured at the northern end of the transcurrent fault system. Elongation and displacement transfer in the eastern block, constituting the southern Walker Lane of western Nevada, exceeds that of the western block and results in the net south to north decrease in displacement on the FC-FLV fault system. Elongation in the eastern block is accommodated by late Miocene to Pliocene detachment faulting followed by extension on superposed, east-northeast striking, high-angle structures. Displacement transfer from the FC-FLV fault system to the northwest-trending faults of the central Walker Lane to the north is accomplished by motion on a series of west-northwest striking transcurrent faults, named the Oriental Wash, Sylvania Mountain, and Palmetto Mountain fault systems. The west-northwest striking transcurrent faults cross-cut earlier detachment structures and are kinematically linked to east-northeast high-angle extensional faults. The transcurrent faults are mapped along strike for 60 km to the east, where they merge with north-northwest faults forming the eastern boundary of the southern Walker Lane. The west-northwest trending transcurrent faults have 30-35 km of cumulative left-lateral displacement and are a major contributor to the decrease in right-lateral displacement on the FC-FLV fault system.

Fluid-driven normal faulting earthquake sequences in the Taiwan orogen

Science.gov (United States)

Wang, Ling-hua; Rau, Ruey-Juin; Lee, En-Jui

2017-04-01

Seismicity in the Central Range of Taiwan shows normal faulting mechanisms with T-axes directing NE, subparallel to the strike of the mountain belt. We analyze earthquake sequences occurred within 2012-2015 in the Nanshan area of northern Taiwan which indicating swarm behavior and migration characteristics. We select events larger than 2.0 from Central Weather Bureau catalog and use the double-difference relocation program hypoDD with waveform cross-correlation in the Nanshan area. We obtained a final count of 1406 (95%) relocated earthquakes. Moreover, we compute focal mechanisms using USGS program HASH by P-wave first motion and S/P ratio picking and 114 fault plane solutions with M 3.0-5.87 were determined. To test for fluid diffusion, we model seismicity using the equation of Shapiro et al. (1997) by fitting earthquake diffusing rate D during the migration period. According to the relocation result, seismicity in the Taiwan orogenic belt present mostly N25E orientation parallel to the mountain belt with the same direction of the tension axis. In addition, another seismic fracture depicted by seismicity rotated 35 degree counterclockwise to the NW direction. Nearly all focal mechanisms are normal fault type. In the Nanshan area, events show N10W distribution with a focal depth range from 5-12 km and illustrate fault plane dipping about 45-60 degree to SW. Three months before the M 5.87 mainshock which occurred in March, 2013, there were some foreshock events occurred in the shallow part of the fault plane of the mainshock. Half a year following the mainshock, earthquakes migrated to the north and south, respectively with processes matched the diffusion model at a rate of 0.2-0.6 m2/s. This migration pattern and diffusion rate offer an evidence of 'fluid-driven' process in the fault zone. We also find the upward migration of earthquakes in the mainshock source region. These phenomena are likely caused by the opening of the permeable conduit due to the M 5

A gravity slide origin for the Mormon Peak detachment: Re-examining the evidence for extreme extension in the Mormon Mountains, southeastern Nevada, U.S.A

Science.gov (United States)

Walker, Christopher David

The Mormon Peak detachment is an enigmatic, low-angle surface that cuts almost all other structures in the Mormon Mountains of southeast Nevada. It has been described as both a large-magnitude offset, low-angle normal fault and as a rootless gravity slide. The two models have been tested, and the gravity slide model explains the geology exposed in the range better than the extreme extension model. Kinematic indicators on the detachment show down-dip motion. Structure contours delimit discrete domains. Exhumed structures reveal no large-magnitude offset between the Meadow Valley and Mormon Mountains. Thermochronological modeling indicates basin-wide exhumation beginning at ˜23--17 Ma. Field mapping documents a pervasive role for long-lived high-angle normal faults with spatially and temporally restricted detachment formation events, and measurements of the volume of rock contained in the hanging wall show it required only a small source area with respect to the size of the range. Regional crustal extension from the Meadow Valley Mountains to the Beaver Dam Mountains is approximately 25%, an order of magnitude less than previously interpreted. The conclusions from the Mormon Mountains were applied to several interpreted detachment faults elsewhere and a set of criteria developed to help future workers distinguish between rooted structures that accommodate crustal extension and rootless structures that do not.

Analysis of the impact of fault mechanism radiation patterns on macroseismic fields in the epicentral area of 1998 and 2004 Krn Mountains earthquakes (NW Slovenia).

Science.gov (United States)

Gosar, Andrej

2014-01-01

Two moderate magnitude (Mw = 5.6 and 5.2) earthquakes in Krn Mountains occurred in 1998 and 2004 which had maximum intensity VII-VIII and VI-VII EMS-98, respectively. Comparison of both macroseismic fields showed unexpected differences in the epicentral area which cannot be explained by site effects. Considerably, different distribution of the highest intensities can be noticed with respect to the strike of the seismogenic fault and in some localities even higher intensities have been estimated for the smaller earthquake. Although hypocentres of both earthquakes were only 2 km apart and were located on the same seismogenic Ravne fault, their focal mechanisms showed a slight difference: almost pure dextral strike-slip for the first event and a strike-slip with small reverse component on a steep fault plane for the second one. Seismotectonically the difference is explained as an active growth of the Ravne fault at its NW end. The radiation patterns of both events were studied to explain their possible impact on the observed variations in macroseismic fields and damage distribution. Radiation amplitude lobes were computed for three orthogonal directions: radial P, SV, and SH. The highest intensities of both earthquakes were systematically observed in directions of four (1998) or two (2004) large amplitude lobes in SH component (which corresponds mainly to Love waves), which have significantly different orientation for both events. On the other hand, radial P direction, which is almost purely symmetrical for the strike-slip mechanism of 1998 event, showed for the 2004 event that its small reverse component of movement has resulted in a very pronounced amplitude lobe in SW direction where two settlements are located which expressed higher intensities in the case of the 2004 event with respect to the 1998 one. Although both macroseismic fields are very complex due to influences of multiple earthquakes, retrofitting activity after 1998, site effects, and sparse

A preliminary assessment of earthquake ground shaking hazard at Yucca Mountain, Nevada and implications to the Las Vegas region

International Nuclear Information System (INIS)

Wong, I.G.; Green, R.K.; Sun, J.I.; Pezzopane, S.K.; Abrahamson, N.A.; Quittmeyer, R.C.

1996-01-01

As part of early design studies for the potential Yucca Mountain nuclear waste repository, the authors have performed a preliminary probabilistic seismic hazard analysis of ground shaking. A total of 88 Quaternary faults within 100 km of the site were considered in the hazard analysis. They were characterized in terms of their probability o being seismogenic, and their geometry, maximum earthquake magnitude, recurrence model, and slip rate. Individual faults were characterized by maximum earthquakes that ranged from moment magnitude (M w ) 5.1 to 7.6. Fault slip rates ranged from a very low 0.00001 mm/yr to as much as 4 mm/yr. An areal source zone representing background earthquakes up to M w 6 1/4 = 1/4 was also included in the analysis. Recurrence for these background events was based on the 1904--1994 historical record, which contains events up to M w 5.6. Based on this analysis, the peak horizontal rock accelerations are 0.16, 0.21, 0.28, and 0.50 g for return periods of 500, 1,000, 2,000, and 10,000 years, respectively. In general, the dominant contributor to the ground shaking hazard at Yucca Mountain are background earthquakes because of the low slip rates of the Basin and Range faults. A significant effect on the probabilistic ground motions is due to the inclusion of a new attenuation relation developed specifically for earthquakes in extensional tectonic regimes. This relation gives significantly lower peak accelerations than five other predominantly California-based relations used in the analysis, possibly due to the lower stress drops of extensional earthquakes compared to California events. Because Las Vegas is located within the same tectonic regime as Yucca Mountain, the seismic sources and path and site factors affecting the seismic hazard at Yucca Mountain also have implications to Las Vegas. These implications are discussed in this paper

Evaluation of the Location and Recency of Faulting Near Prospective Surface Facilities in Midway Valley, Nye County, Nevada

Science.gov (United States)

Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

2001-01-01

Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern

Evaluation of the location and recency of faulting near prospective surface facilities in Midway Valley, Nye County, Nevada

Energy Technology Data Exchange (ETDEWEB)

Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

2002-01-17

Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern

Evaluation of the location and recency of faulting near prospective surface facilities in Midway Valley, Nye County, Nevada

International Nuclear Information System (INIS)

Swan, F.H.; Wesling, J.R.; Angell, M.M.; Thomas, A.P.; Whitney, J.W.; Gibson, J.D.

2002-01-01

Evaluation of surface faulting that may pose a hazard to prospective surface facilities is an important element of the tectonic studies for the potential Yucca Mountain high-level radioactive waste repository in southwestern Nevada. For this purpose, a program of detailed geologic mapping and trenching was done to obtain surface and near-surface geologic data that are essential for determining the location and recency of faults at a prospective surface-facilities site located east of Exile Hill in Midway Valley, near the eastern base of Yucca Mountain. The dominant tectonic features in the Midway Valley area are the north- to northeast-trending, west-dipping normal faults that bound the Midway Valley structural block-the Bow Ridge fault on the west side of Exile Hill and the Paint-brush Canyon fault on the east side of the valley. Trenching of Quaternary sediments has exposed evidence of displacements, which demonstrate that these block-bounding faults repeatedly ruptured the surface during the middle to late Quaternary. Geologic mapping, subsurface borehole and geophysical data, and the results of trenching activities indicate the presence of north- to northeast-trending faults and northwest-trending faults in Tertiary volcanic rocks beneath alluvial and colluvial sediments near the prospective surface-facilities site. North to northeast-trending faults include the Exile Hill fault along the eastern base of Exile Hill and faults to the east beneath the surficial deposits of Midway Valley. These faults have no geomorphic expression, but two north- to northeast-trending zones of fractures exposed in excavated profiles of middle to late Pleistocene deposits at the prospective surface-facilities site appear to be associated with these faults. Northwest-trending faults include the West Portal and East Portal faults, but no disruption of Quaternary deposits by these faults is evident. The western zone of fractures is associated with the Exile Hill fault. The eastern

The continuation of the Kazerun fault system across the Sanandaj-Sirjan zone (Iran)

Science.gov (United States)

Safaei, Homayon

2009-08-01

The Kazerun (or Kazerun-Qatar) fault system is a north-trending dextral strike-slip fault zone in the Zagros mountain belt of Iran. It probably originated as a structure in the Panafrican basement. This fault system played an important role in the sedimentation and deformation of the Phanerozoic cover sequence and is still seismically active. No previous studies have reported the continuation of this important and ancient fault system northward across the Sanandaj-Sirjan zone. The Isfahan fault system is a north-trending dextral strike-slip fault across the Sanandaj-Sirjan zone that passes west of Isfahan city and is here recognized for the first time. This important fault system is about 220 km long and is seismically active in the basement as well as the sedimentary cover sequence. This fault system terminates to the south near the Main Zagros Thrust and to the north at the southern boundary of the Urumieh-Dokhtar zone. The Isfahan fault system is the boundary between the northern and southern parts of Sanandaj-Sirjan zone, which have fundamentally different stratigraphy, petrology, geomorphology, and geodynamic histories. Similarities in the orientations, kinematics, and geologic histories of the Isfahan and Kazerun faults and the way they affect the magnetic basement suggest that they are related. In fact, the Isfahan fault is a continuation of the Kazerun fault across the Sanandaj-Sirjan zone that has been offset by about 50 km of dextral strike-slip displacement along the Main Zagros Thrust.

Nine-component vertical seismic profiling at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Balch, A.H.; Erdemir, C.; Spengler, R.W.; Hunter, W.C.

1996-01-01

Nine-component vertical seismic profiling has been conducted at the UE-25 UZ No. 16 borehole at Yucca Mountain, Nevada, in support of investigation of the hydrologic significance of fault and fracture systems. A large data set from multi-component sources and receivers allows state-of-the-art advances in processing using polarization filtering and reverse time migration, for enhanced interpretation of geologic features

Meteoric water in normal fault systems: Oxygen and hydrogen isotopic measurements on authigenic phases in brittle fault rocks

Science.gov (United States)

Haines, S. H.; Anderson, R.; Mulch, A.; Solum, J. G.; Valley, J. W.; van der Pluijm, B. A.

2009-12-01

The nature of fluid circulation systems in normal fault systems is fundamental to understanding the nature of fluid movement within the upper crust, and has important implications for the on-going controversy about the strength of faults. Authigenic phases in clay gouges and fault breccias record the isotopic signature of the fluids they formed in equilibrium with, and can be used to understand the ‘plumbing system’ of brittle fault environments. We obtained paired oxygen and hydrogen isotopic measurements on authigenic illite and/or smectite in clay gouge from normal faults in two geologic environments, 1.) low-angle normal faults (Ruby Mountains detachment, NV; Badwater Turtleback, CA; Panamint range-front detachment; CA; Amargosa detachment; CA; Waterman Hills detachment, CA), and 2.) An intracratonic high-angle normal fault (Moab Fault, UT). All authigenic phases in these clay gouges are moderately light isotopically with respect to oxygen (illite δ18O -2.0 - + 11.5 ‰ SMOW, smectite δ18O +3.6 and 17.9 ‰) and very light isotopically with respect to hydrogen (illite δD -148 to -98 ‰ SMOW, smectite δD -147 to -92 ‰). Fluid compositions calculated from the authigenic clays at temperatures of 50 - 130 ○C (as indicated by clay mineralogy) indicate that both illite and smectite in normal fault clay gouge formed in the presence of near-pristine to moderately-evolved meteoric fluids and that igneous or metamorphic fluids are not involved in clay gouge formation in these normal fault settings. We also obtained paired oxygen and hydrogen isotopic measurements on chlorites derived from footwall chlorite breccias in 4 low-angle normal fault detachment systems (Badwater and Mormon Point Turtlebacks, CA, the Chemehuevi detachment, CA, and the Buckskin-Rawhide detachment, AZ). All chlorites are isotopically light to moderately light with respect to oxygen (δ18O +0.29 to +8.1 ‰ SMOW) and very light with respect to hydrogen (δD -97 to -113 ‰) and indicate

Recent progress in fission at saddle point and scission point

International Nuclear Information System (INIS)

Blons, J.; Paya, D.; Signarbieux, C.

High resolution measurements of 230 Th and 232 Th fission cross sections for neutrons exhibit a fine structure. Such a structure is interpreted as a superposition of two rotational bands in the third, asymmetric, well of the fission barrier. The fragment mass distribution in the thermal fission of 235 U and 233 U does not show any even-odd effect, even at the highest kinetic energies. This is the mark of a strong viscosity in the descent from saddle point to scission point [fr

Guatemala paleoseismicity: from Late Classic Maya collapse to recent fault creep

Science.gov (United States)

Brocard, Gilles; Anselmetti, Flavio S.; Teyssier, Christian

2016-11-01

We combine ‘on-fault’ trench observations of slip on the Polochic fault (North America-Caribbean plate boundary) with a 1200 years-long ‘near-fault’ record of seismo-turbidite generation in a lake located within 2 km of the fault. The lake record indicates that, over the past 12 centuries, 10 earthquakes reaching ground-shaking intensities ≥ VI generated seismo-turbidites in the lake. Seismic activity was highly unevenly distributed over time and noticeably includes a cluster of earthquakes spread over a century at the end of the Classic Maya period. This cluster may have contributed to the piecemeal collapse of the Classic Maya civilization in this wet, mountainous southern part of the Maya realm. On-fault observations within 7 km of the lake show that soils formed between 1665 and 1813 CE were displaced by the Polochic fault during a long period of seismic quiescence, from 1450 to 1976 CE. Displacement on the Polochic fault during at least the last 480 years included a component of slip that was aseismic, or associated with very light seismicity (magnitude 1 ky) punctuated by destructive earthquake clusters.

Fluvial-Deltaic Strata as a High-Resolution Recorder of Fold Growth and Fault Slip

Science.gov (United States)

Anastasio, D. J.; Kodama, K. P.; Pazzaglia, F. P.

2008-12-01

Fluvial-deltaic systems characterize the depositional record of most wedge-top and foreland basins, where the synorogenic stratigraphy responds to interactions between sediment supply driven by tectonic uplift, climate modulated sea level change and erosion rate variability, and fold growth patterns driven by unsteady fault slip. We integrate kinematic models of fault-related folds with growth strata and fluvial terrace records to determine incremental rates of shortening, rock uplift, limb tilting, and fault slip with 104-105 year temporal resolution in the Pyrenees and Apennines. At Pico del Aguila anticline, a transverse dècollement fold along the south Pyrenean mountain front, formation-scale synorogenic deposition and clastic facies patterns in prodeltaic and slope facies reflect tectonic forcing of sediment supply, sea level variability controlling delta front position, and climate modulated changes in terrestrial runoff. Growth geometries record a pinned anticline and migrating syncline hinges during folding above the emerging Guarga thrust sheet. Lithologic and anhysteretic remanent magnetization (ARM) data series from the Eocene Arguis Fm. show cyclicity at Milankovitch frequencies allowing detailed reconstruction of unsteady fold growth. Multiple variations in limb tilting rates from roof ramp and basal dècollement. Along the northern Apennine mountain front, the age and geometry of strath terraces preserved across the Salsomaggiore anticline records the Pleistocene-Recent kinematics of the underlying fault-propagation fold as occurring with a fixed anticline hinge, a rolling syncline hinge, and along-strike variations in uplift and forelimb tilting. The uplifted intersection of terrace deposits documents syncline axial surface migration and underlying fault-tip propagation at a rate of ~1.4 cm/yr since the Middle Pleistocene. Because this record of fault slip coincides with the well-known large amplitude oscillations in global climate that contribute

Normal Faulting in the 1923 Berdún Earthquake and Postorogenic Extension in the Pyrenees

Science.gov (United States)

Stich, Daniel; Martín, Rosa; Batlló, Josep; Macià, Ramón; Mancilla, Flor de Lis; Morales, Jose

2018-04-01

The 10 July 1923 earthquake near Berdún (Spain) is the largest instrumentally recorded event in the Pyrenees. We recover old analog seismograms and use 20 hand-digitized waveforms for regional moment tensor inversion. We estimate moment magnitude Mw 5.4, centroid depth of 8 km, and a pure normal faulting source with strike parallel to the mountain chain (N292°E), dip of 66° and rake of -88°. The new mechanism fits into the general predominance of normal faulting in the Pyrenees and extension inferred from Global Positioning System data. The unique location of the 1923 earthquake, near the south Pyrenean thrust front, shows that the extensional regime is not confined to the axial zone where high topography and the crustal root are located. Together with seismicity near the northern mountain front, this indicates that gravitational potential energy in the western Pyrenees is not extracted locally but induces a wide distribution of postorogenic deformation.

Denudation history of the Snowy Mountains: constraints from apatite fission track thermochronology

International Nuclear Information System (INIS)

Kohn, B.P.; Gleadow, A.J.W.; Cox, S.J.D.

1999-01-01

Apatite fission track thermo chronology from Early Palaeozoic granitoids centred around the Kosciuszko massif of the Snowy Mountains, records a denudation history that was episodic and highly variable. The form of the apatite fission track age profile assembled from vertical sections and hydro-electric tunnels traversing the mountains, together with numerical forward modelling, provide strong evidence for two episodes of accelerated denudation, commencing in Late Permian - Early Triassic (ca 270 250 Ma) and mid-Cretaceous (ca 110-100 Ma) times, and a possible third episode in the Cenozoic. Denudation commencing in the Late Permian - Early Triassic wins widespread in the eastern and Central Snowy Mountains area, continued through much of the Triassic, and amounted to at least ∼2.0-2,4 km. This episode was probably the geomorphic response to the Hunter-Bowen Orogeny. Post-Triassic denudation to the present in these areas amounted to ∼2.0-2.2 km. Unambiguous evidence for mid-Cretaceous cooling and possible later cooling is confined to a north-south-trending sinuous belt, up to ∼15km wide by at least 35km long, of major reactivated Palaeozoic faults on the western side of the mountains. This zone is the most deeply exposed area of the Kosciuszko block. Denudation accompanying these later events totalled up to ∼1.8-2.0 km and ∼2.0 2.25 km respectively. Mid-Cretaceous denudation marks the onset of renewed tectonic activity in the south-eastern highlands following a period of relative quiescence since the Late Triassic, and establishes a temporal link with the onset of extension related to the opening of the Tasman Sea. Much of the present day relief of the mountains resulted from surface uplift which disrupted the post-mid-Cretaceous apatite fission track profile by variable offsets on faults. Copyright (1999) Geological Society of Australia

Preclosure seismic design methodology for a geologic repository at Yucca Mountain. Revision 1

International Nuclear Information System (INIS)

1996-08-01

This topical report is the second in a series of three reports being developed by the US Department of Energy (DOE) to document the preclosure seismic design of structures, systems, and components (SSCs) that are important to the radiological safety of the potential repository at Yucca Mountain, Nevada. The first topical report, Methodology to Assess Fault Displacement and Vibratory Ground Motion Hazards at Yucca Mountain, YMP/TR-002-NP, was submitted to the US Nuclear Regulatory Commission (NRC) staff for review and comment in 1994 and has been accepted by the staff. The DOE plans to implement this methodology in fiscal year 1997 to develop probabilistic descriptions of the vibratory ground motion hazard and the fault displacement hazard at the Yucca Mountain site. The second topical report (this report) describes the DOE methodology and acceptance criteria for the preclosure seismic design of SSCs important to safety. A third report, scheduled for fiscal year 1998, will document the results of the probabilistic seismic hazard assessment (conducted using the methodology in the first topical report) and the development of the preclosure seismic design inputs. This third report will be submitted to NRC staff for review and comment as a third topical report or as a design study report

Evolution of the unsaturated zone testing at Yucca Mountain

International Nuclear Information System (INIS)

Wang, J.S.Y.; Bodvarsson, G.S.

2002-01-01

The evaluation of the Yucca Mountain site has evolved from intensive surface based investigations in the early 1980s to current focus on testing in underground drifts. Different periods of site-characterization activities and prominent issues concerning the unsaturated zone are summarized. Data-collection activities have evolved from mapping of faults and fractures, to estimation of percolation through tuff layers, and to quantification of seepage into drifts. Evaluation of discrete flow paths in drifts has led to fracture-matrix interaction and matrix diffusion tests over different scales. The effects of tuff interfaces and local faults are evaluated in fractured-welded and porous-nonwelded units. Mobilization of matrix water and redistribution of moisture are measured in thermal tests. Lessons learned from underground tests are used to focus on processes needed for additional quantification. Migration through the drift shadow zone and liquid flow through faults are two important issues that have evolved from current knowledge

On the late-time behavior of Virasoro blocks and a classification of semiclassical saddles

Energy Technology Data Exchange (ETDEWEB)

Fitzpatrick, A. Liam [Department of Physics, Boston University,Commonwealth Avenue, Boston, MA 02215 (United States); Kaplan, Jared [Department of Physics and Astronomy, Johns Hopkins University,Charles Street, Baltimore, MD 21218 (United States)

2017-04-12

Recent work has demonstrated that black hole thermodynamics and information loss/restoration in AdS{sub 3}/CFT{sub 2} can be derived almost entirely from the behavior of the Virasoro conformal blocks at large central charge, with relatively little dependence on the precise details of the CFT spectrum or OPE coefficients. Here, we elaborate on the non-perturbative behavior of Virasoro blocks by classifying all ‘saddles’ that can contribute for arbitrary values of external and internal operator dimensions in the semiclassical large central charge limit. The leading saddles, which determine the naive semiclassical behavior of the Virasoro blocks, all decay exponentially at late times, and at a rate that is independent of internal operator dimensions. Consequently, the semiclassical contribution of a finite number of high-energy states cannot resolve a well-known version of the information loss problem in AdS{sub 3}. However, we identify two infinite classes of sub-leading saddles, and one of these classes does not decay at late times.

Landforms along transverse faults parallel to axial zone of folded mountain front, north-eastern Kumaun Sub-Himalaya, India

Science.gov (United States)

Luirei, Khayingshing; Bhakuni, S. S.; Negi, Sanjay S.

2017-02-01

The shape of the frontal part of the Himalaya around the north-eastern corner of the Kumaun Sub-Himalaya, along the Kali River valley, is defined by folded hanging wall rocks of the Himalayan Frontal Thrust (HFT). Two parallel faults (Kalaunia and Tanakpur faults) trace along the axial zone of the folded HFT. Between these faults, the hinge zone of this transverse fold is relatively straight and along these faults, the beds abruptly change their attitudes and their widths are tectonically attenuated across two hinge lines of fold. The area is constituted of various surfaces of coalescing fans and terraces. Fans comprise predominantly of sandstone clasts laid down by the steep-gradient streams originating from the Siwalik range. The alluvial fans are characterised by compound and superimposed fans with high relief, which are generated by the tectonic activities associated with the thrusting along the HFT. The truncated fan along the HFT has formed a 100 m high-escarpment running E-W for ˜5 km. Quaternary terrace deposits suggest two phases of tectonic uplift in the basal part of the hanging wall block of the HFT dipping towards the north. The first phase is represented by tilting of the terrace sediments by ˜30 ∘ towards the NW; while the second phase is evident from deformed structures in the terrace deposit comprising mainly of reverse faults, fault propagation folds, convolute laminations, flower structures and back thrust faults. The second phase produced ˜1.0 m offset of stratification of the terrace along a thrust fault. Tectonic escarpments are recognised across the splay thrust near south of the HFT trace. The south facing hill slopes exhibit numerous landslides along active channels incising the hanging wall rocks of the HFT. The study area shows weak seismicity. The major Moradabad Fault crosses near the study area. This transverse fault may have suppressed the seismicity in the Tanakpur area, and the movement along the Moradabad and Kasganj

Fault Slip Partitioning in the Eastern California Shear Zone-Walker Lane Belt: Pliocene to Late Pleistocene Contraction Across the Mina Deflection

Science.gov (United States)

Lee, J.; Stockli, D.; Gosse, J.

2007-12-01

Two different mechanisms have been proposed for fault slip transfer between the subparallel NW-striking dextral- slip faults that dominant the Eastern California Shear Zone (ECSZ)-Walker Lane Belt (WLB). In the northern WLB, domains of sinistral-slip along NE-striking faults and clockwise block rotation within a zone of distributed deformation accommodated NW-dextral shear. A somewhat modified version of this mechanism was also proposed for the Mina deflection, southern WLB, whereby NE-striking sinistral faults formed as conjugate faults to the primary zone of NW-dextral shear; clockwise rotation of the blocks bounding the sinistral faults accommodated dextral slip. In contrast, in the northern ECSZ and Mina deflection, domains of NE-striking pure dip-slip normal faults, bounded by NW-striking dextral-slip faults, exhibited no rotation; the proposed mechanism of slip transfer was one of right-stepping, high angle normal faults in which the magnitude of extension was proportional to the amount of strike-slip motion transferred. New geologic mapping, tectonic geomorphologic, and geochronologic data from the Queen Valley area, southern Mina deflection constrain Pliocene to late Quaternary fault geometries, slip orientations, slip magnitudes, and slip rates that bear on the mechanism of fault slip transfer from the relatively narrow northern ECSZ to the broad deformation zone that defines the Mina deflection. Four different fault types and orientations cut across the Queen Valley area: (1) The NE-striking normal-slip Queen Valley fault; (2) NE-striking sinistral faults; (3) the NW-striking dextral Coyote Springs fault, which merges into (4) a set of EW-striking thrust faults. (U-Th)/He apatite and cosmogenic radionuclide data, combined with magnitude of fault offset measurements, indicate a Pliocene to late Pleistocene horizontal extension rate of 0.2-0.3 mm/yr across the Queen Valley fault. Our results, combined with published slip rates for the dextral White Mountain

Plutons and accretionary episodes of the Klamath Mountains, California and Oregon

Science.gov (United States)

Irwin, William P.; Wooden, Joseph L.

1999-01-01

The Klamath Mountains consist of various accreted terranes and include many plutons that range in composition from gabbro to granodiorite. Some of the plutons (preaccretionary plutons) were parts of terranes before the terranes accreted; others (accretionary plutons) intruded during or after the accretion of their host terrane(s). This report attempts to (1) graphically illustrate how the Klamath Mountains grew by the accretion of allochthonous oceanic terranes during early Paleozoic to Cretaceous times, (2) identify the plutons as either preaccretionary or accretionary, and (3) genetically relate the plutonic intrusions to specific accretionary episodes. The eight accretionary episodes portrayed in this report are similar to those shown by Irwin and Mankinen (1998) who briefly described the basis for the timing of the episodes and who illustrated the ~110 degrees of clockwise rotation of the Klamath Mountains since Early Devonian time. Each episode is named for the accreting terrane. In all episodes (Figs. 1-8), the heavy black line represents a fault that separates the accreting oceanic rocks on the left from earlier accreted terranes on the right. The preaccretionary plutons are shown within the accreting oceanic crustal rocks to the left of the heavy black line, and the accretionary plutons in most instances are shown intruding previously accreted terranes to the right. Episodes earlier than the Central Metamorphic episode (Fig. 1), and that may have been important in the formation of the early Paleozoic nucleous of the province (the Eastern Klamath terrane), are not known. The 'Present Time' distribution of the accreted terranes and plutons is shown at a large scale in Figure 9. The schematic vertical section (Fig. 10) depicts the terranes as a stack of horizontal slabs that include or are intruded by vertical plutons. Note that at their base the ~170 Ma preaccretionary plutons of the Western Hayfork subterrane are truncated by the ~164 Ma Salt Creek

On preconditioner updates for sequences of saddle-point linear systems

Directory of Open Access Journals (Sweden)

Simone Valentina De

2018-02-01

Full Text Available Updating preconditioners for the solution of sequences of large and sparse saddle- point linear systems via Krylov methods has received increasing attention in the last few years, because it allows to reduce the cost of preconditioning while keeping the efficiency of the overall solution process. This paper provides a short survey of the two approaches proposed in the literature for this problem: updating the factors of a preconditioner available in a block LDLT form, and updating a preconditioner via a limited-memory technique inspired by quasi-Newton methods.

Triangular preconditioners for saddle point problems with a penalty term

Energy Technology Data Exchange (ETDEWEB)

Klawonn, A. [Westfaelische Wilhelms-Universitaet, Muenster (Germany)

1996-12-31

Triangular preconditioners for a class of saddle point problems with a penalty term are considered. An important example is the mixed formulation of the pure displacement problem in linear elasticity. It is shown that the spectrum of the preconditioned system is contained in a real, positive interval, and that the interval bounds can be made independent of the discretization and penalty parameters. This fact is used to construct bounds of the convergence rate of the GMRES method used with an energy norm. Numerical results are given for GMRES and BI-CGSTAB.

Site characterization progress report: Yucca Mountain, Nevada, April 1, 1992--September 30, 1992, Number 7

International Nuclear Information System (INIS)

1992-12-01

In accordance with section 113(b)(3) of the Nuclear Waste Policy Act of 1982, as amended (NWPA), the Department has prepared the seventh in a series of reports on the progress of site characterization at the Yucca Mountain candidate site. The Civilian Radioactive Waste Management Program made significant progress during the reporting period at the Yucca Mountain Site Characterization Project. Several important advances were made in the surface-based testing program including: initiation of borehole drilling utilizing the new, state-of-the-art LM-300 drill rig which employs dry drilling and coring techniques; neutron access borehole drilling to evaluate infiltration processes; excavations to aid geologic mapping; and trenching in Midway Valley to study Quaternary faulting. A Floodplain Assessment and Statement of Findings was published in the Federal Register which concluded there would be no significant impact nor cumulative impacts on floodplains resulting from Exploratory Studies Facility activities. The National Academy of Sciences' National Research Council released its report entitled ''Ground Water at Yucca Mountain: How High Can It Rise?'' which concluded that none of the evidence cited as proof of groundwater upwelling in and around Yucca Mountain could be reasonably attributed to that process and that significant water table excursions to the repository design level are not shown by the geologic record. The June 29, 1992, earthquake near Yucca Mountain provided scientists with a wealth of information relevant to understanding the neotectonics of the area and the geometry of faults at depth. Early findings suggest that accelerations recorded were well within proposed design limits for the surface waste handling facilities

Site characterization progress report: Yucca Mountain, Nevada, April 1, 1992--September 30, 1992, Number 7

Energy Technology Data Exchange (ETDEWEB)

NONE

1992-12-01

In accordance with section 113(b)(3) of the Nuclear Waste Policy Act of 1982, as amended (NWPA), the Department has prepared the seventh in a series of reports on the progress of site characterization at the Yucca Mountain candidate site. The Civilian Radioactive Waste Management Program made significant progress during the reporting period at the Yucca Mountain Site Characterization Project. Several important advances were made in the surface-based testing program including: initiation of borehole drilling utilizing the new, state-of-the-art LM-300 drill rig which employs dry drilling and coring techniques; neutron access borehole drilling to evaluate infiltration processes; excavations to aid geologic mapping; and trenching in Midway Valley to study Quaternary faulting. A Floodplain Assessment and Statement of Findings was published in the Federal Register which concluded there would be no significant impact nor cumulative impacts on floodplains resulting from Exploratory Studies Facility activities. The National Academy of Sciences` National Research Council released its report entitled ``Ground Water at Yucca Mountain: How High Can It Rise?`` which concluded that none of the evidence cited as proof of groundwater upwelling in and around Yucca Mountain could be reasonably attributed to that process and that significant water table excursions to the repository design level are not shown by the geologic record. The June 29, 1992, earthquake near Yucca Mountain provided scientists with a wealth of information relevant to understanding the neotectonics of the area and the geometry of faults at depth. Early findings suggest that accelerations recorded were well within proposed design limits for the surface waste handling facilities.

Boundary element analysis of active mountain building and stress heterogeneity proximal to the 2015 Nepal earthquake

Science.gov (United States)

Thompson, T. B.; Meade, B. J.

2015-12-01

The Himalayas are the tallest mountains on Earth with ten peaks exceeding 8000 meters, including Mt. Everest. The geometrically complex fault system at the Himalayan Range Front produces both great relief and great earthquakes, like the recent Mw=7.8 Nepal rupture. Here, we develop geometrically accurate elastic boundary element models of the fault system at the Himalayan Range Front including the Main Central Thrust, South Tibetan Detachment, Main Frontal Thrust, Main Boundary Thrust, the basal detachment, and surface topography. Using these models, we constrain the tectonic driving forces and frictional fault strength required to explain Quaternary fault slip rate estimates. These models provide a characterization of the heterogeneity of internal stress in the region surrounding the 2015 Nepal earthquake.

A new vision of the intracontinental evolution of the eastern Kunlun Mountains, Northern Qinghai-Tibet plateau, China

International Nuclear Information System (INIS)

Yuan, W.-M.; Zhang, X.-T.; Dong, J.-Q.; Tang, Y.-H.; Yu, F.-S.; Wang, S.-C.

2003-01-01

Based on apatite fission track ages (FTA) of 41 samples collected from a south-north transect of the eastern Kunlun mountains, Qinghai-Tibet Plateau, China, this paper shows that (1) the FTA in different blocks increases with the distance from the South-Kunlun fault and Mid-Kunlun faults, respectively, indicating the control of the main faults on the tectonic evolution of this region; and (2) the thermal histories are characterized by slow cooling from ∼160 deg. C to ∼80 deg. C at ∼240 to ∼20 Ma, followed by rather rapid cooling to surface temperatures

The Upper Devonian deposits in the northern part of Leon (Cantabrian Mountains, Northwestern Spain)

NARCIS (Netherlands)

Loevezijn, van G.B.S.; Raven, J.G.M.

1983-01-01

During the Late Devonian, deposition in the Cantabrian Mountains was largely controlled by movements along faults. By way of intermitting subsidence of the area south of the Sabero-Gordón line and the connected progradation of the coast during the Frasnian and early Famennian, three regressive

The use of TOUGH2 for the LBL/USGS 3-dimensional site-scale model of Yucca Mountain, Nevada

Energy Technology Data Exchange (ETDEWEB)

Bodvarsson, G.; Chen, G.; Haukwa, C. [Lawrence Berkeley Laboratory, CA (United States)] [and others

1995-03-01

The three-dimensional site-scale numerical model of the unsaturated zone at Yucca Mountain is under continuous development and calibration through a collaborative effort between Lawrence Berkeley Laboratory (LBL) and the United States Geological Survey (USGS). The site-scale model covers an area of about 30 km{sup 2} and is bounded by major fault zones to the west (Solitario Canyon Fault), east (Bow Ridge Fault) and perhaps to the north by an unconfirmed fault (Yucca Wash Fault). The model consists of about 5,000 grid blocks (elements) with nearly 20,000 connections between them the grid was designed to represent the most prevalent geological and hydro-geological features of the site including major faults, and layering and bedding of the hydro-geological units. Further information about the three-dimensional site-scale model is given by Wittwer et al. and Bodvarsson et al.

The Bocono Fault Zone, Western Venezuela

Energy Technology Data Exchange (ETDEWEB)

Schubert, C. (I.V.I.C., Caracas (Venezuela)); Estevez, R. (Universidad de los Andes, Merida (Venezuela)); Henneberg, H.G. (Universidad del Zulia, Maracaibo (Venezuela))

1993-02-01

The Bocono Fault Zone, the western part of the Bocono Moron-El Pilar Fault System of the southern Caribbean plate boundary, consists of aligned valleys, linear depressions, pull-apart basins and other morphological features, which extend for about 500 km in a N45[degrees]E direction, between the Tachira depression (Venezuela-Colombia border) and the Caribbean Sea. It crosses obliquely the Cordillera de Merida and cuts across the Caribbean Mountains, two different geologic provinces of Late Tertiary-Quaternary and Late Cretaceous-Early Tertiary age, respectively. Therefore, the maximum age that can be assigned to the Bocono Fault Zone is Late Tertiary (probably Pliocene). A total maximum right-lateral offset rate of 3.3 mm/a. The age of the sedimentary fill o[approximately] the La Gonzalez pull-apart basin suggests that the 7-9 km right-lateral offset necessary to produce it took place in Middle to Late Pleistocene time. The majority of seismic events are well aligned with the main fault trace; minor events are distributed in a belt several kilometers wide. Focal depth is typically 15 km and focal mechanisms indicate an average east-west compression across the zone. Return periods of 135-460 a (Richter M = 8), 45-70 a (M = 7), and 7-15 a (M = 6) have been calculated. Geodetic studies of several sites along the zone indicate compressive and right-lateral components; at Mucubaji the rate of right-lateral displacement observed is about 1 mm every 5 months (15 a of measurements).

Summary and evaluation of existing geological and geophysical data near prospective surface facilities in Midway Valley, Yucca Mountain Project, Nye County, Nevada

International Nuclear Information System (INIS)

Gibson, J.D.; Swan, F.H.; Wesling, J.R.; Bullard, T.F.; Perman, R.C.; Angell, M.M.; DiSilvestro, L.A.

1992-01-01

Midway Valley, located at the eastern base of the Yucca Mountain in southwestern Nevada, is the preferred location of the surface facilities for the potential high-level nuclear waste repository at Yucca Mountain. One goal in siting these surface facilities is to avoid faults that could produce relative displacements in excess of 5 cm in the foundations of the waste-handling buildings. This study reviews existing geologic and geophysical data that can be used to assess the potential for surface fault rupture within Midway Valley. Dominant tectonic features in Midway Valley are north-trending, westward-dipping normal faults along the margins of the valley: the Bow Ridge fault to the west and the Paintbrush Canyon fault to the east. Published estimates of average Quaternary slip rates for these faults are very low but the age of most recent displacement and the amount of displacement per event are largely unknown. Surface mapping and interpretive cross sections, based on limited drillhole and geophysical data, suggest that additional normal faults, including the postulated Midway Valley fault, may exist beneath the Quaternary/Tertiary fill within the valley. Existing data, however, are inadequate to determine the location, recency, and geometry of this faulting. To confidently assess the potential for significant Quaternary faulting in Midway Valley, additional data are needed that define the stratigraphy and structure of the strata beneath the valley, characterize the Quaternary soils and surfaces, and establish the age of faulting. The use of new and improved geophysical techniques, combined with a drilling program, offers the greatest potential for resolving subsurface structure in the valley. Mapping of surficial geologic units and logging of soil pits and trenches within these units must be completed, using accepted state-of-the-art practices supported by multiple quantitative numerical and relative age-dating techniques

Structural and metamorphic evolution of the Orocopia Schist and related rocks, southern California: Evidence for late movement on the Orocopia fault

Science.gov (United States)

Jacobson, Carl E.; Dawson, M. Robert

1995-08-01

The Pelona, Orocopia, and Rand Schists (POR schists) of southern California and southwesternmost Arizona are late Mesozoic or early Tertiary subduction complexes that underlie Precambrian to Mesozoic continental basement along the low-angle Vincent-Chocolate Mountains (VCM) fault system. The VCM faults are often considered to be remnants of the original subduction zone, but recent work indicates that many have undergone substantial postsubduction reactivation. In the Orocopia Mountains, for example, the Orocopia Schist exhibits an exceptionally complex structural and metamorphic history due to multiple periods of movement along the Orocopia fault. Structures in the schist include isoclinal folds with axial-planar schistosity, open-to-tight folds that fold schistosity, penetrative stretching lineations, and crenulation lineations, all of which show a nearly 360° range in trend. Folds and lineations that trend approximately NE-SW occur throughout the schist and are thought to be part of an early phase of deformation related to subduction. Folds of this orientation show no consistent vergence. Folds and lineations that trend approximately NW-SE are concentrated near the Orocopia fault and are interpreted to have formed during exhumation of the schist. The NW-SE trending folds, and shear indicators in late-stage mylonite at the top of the schist, consistently verge NE. The exhumation event culminated in emplacement of the schist against brittlely deformed upper plate. Exhumation of the Orocopia Schist was accompanied by retrograde replacement of garnet, biotite, epidote, and calcic amphibole by chlorite, calcite, and sericite. Matrix amphibole has a lower Na/Al ratio than amphibole inclusions in albite, consistent with a late-stage decrease in pressure. As NE vergence in the Orocopia Mountains is associated with exhumation of the schist, the NE movement along other segments of the VCM fault may also be late and therefore have no bearing on the facing direction of the

Conductivity Structure of the San Andreas Fault, Parkfield, Revisited

Science.gov (United States)

Park, S. K.; Roberts, J. J.

2003-12-01

Laboratory measurements of samples of sedimentary rocks from the Parkfield syncline reveal resistivities as low as 1 ohm m when saturated with fluids comparable to those found in nearby wells. The syncline lies on the North American side of the San Andreas fault at Parkfield and plunges northwestward into the fault zone. A previous interpretation of a high resolution magnetotelluric profile across the San Andreas fault at Parkfield identified an anomalously conductive (1-3 ohm m) region just west of the fault and extending to depths of 3 km. These low resistivity rocks were inferred to be crushed rock in the fault zone that was saturated with brines. As an alternative to this interpretation, we suggest that this anomalous region is actually the Parkfield syncline and that the current trace of the San Andreas fault at Middle Mountain does not form the boundary between the Salinian block and the North American plate. Instead, that boundary is approximately 1 km west and collocated with current seismicity. This work was performed under the auspices of the U.S. Department of Energy by the University of California Lawrence Livermore National Laboratory under contract W-7405-ENG-48 and supported specifically by the Office of Basic Energy Science. Additional support was provided by the U.S. Geological Survey (USGS), Department of the Interior, under USGS Award number 03HQGR0041. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government.

Rb-Sr and Nd-Sr isotope geochemistry and petrogenesis of the Misho Mountains mafic dikes (NW Iran)

OpenAIRE

Maryam Ahankoub; Yoshihiro Asahar

2017-01-01

Introduction There are some theories about the Paleotethys event during the Paleozoic that have been proposed by geologists (Metcalfe, 2006). Some scientist offered some pieces of evidence about the northern margin of Gondwana (Zhu et al., 2010). The Paleotethys Ocean and Hercynian orogenic report first in Iran, have been Offered from the Morrow and Misho Mountain (Eftekharnejad, 1981). Misho Mountains is located between the north and south Misho faults and cause the formation of a positi...

SANDIA MOUNTAIN WILDERNESS, NEW MEXICO.

Science.gov (United States)

Hedlund, D.C.; Kness, R.F.

1984-01-01

Geologic and mineral-resource investigations in the Sandia Mountains in New Mexico indicate that a small part of the area has a probable mineral-resource potential. Most of the mineral occurrences are small barite-fluorite veins that occur along faults on the eastern slope of the range. The barite veins in the Landsend area and in the Tunnel Spring area are classed as having a probable mineral-resource potential. Fluorite veins which occur at the La Luz mine contain silver-bearing galeana and the area near this mine is regarded as having a probable resource potential for silver. No energy resources were identified in this study.

The activity of the Ulsan fault system based on marine terrace age study at the southeastern part of Korean peninsula

International Nuclear Information System (INIS)

Inoue, Daiei; Weon-Hack, Choi

2006-01-01

The activity evaluation of the Ulsan fault system (UFS) based on marine terrace age study in the southeastern part of Korean peninsula has been carried out. (1) The marine terrace distribution map along the southeastern coast of Korean peninsula has been distributed three wide terraces and several sub-terraces. The age of the above three terraces was determined by the discovery of wide tephras to be MIS5e, 7 and 9 from the lowest, respectively. (2) The active fault map along UFS was constructed. There will be the possibility that the UFS will be divided into three segments by the feature of lineaments. (3) The fault bounds between mountain at the eastern side, and plain at the western side in the most part of fault. It is interpreted that the UFS builds up the eastern mountain as a reverse movement fault. The latest activity of this fault system was clarified at the two localities by outcrop and trench investigation. The latest activity at Galgok-ri located in the northern part of the fault was occurred between 2,840 and 1,440 yBP. It was found to be between 7,470 and 2,990 yBP at Gaegok-ri, located in the central part of the fault. The latest activity at the Wangsan, which is between Galgok-ri and Gaegok-ri, was older than 7,000 yBP. The latest activity of the UFS differs between studied points. (4) The vertical slip rate of the UFS was calculated from the amount of vertical deformation and the age of terraces. Its range was between several cm to 20 cm in the 1000 years. This value corresponds to lower B and C class activity defined in Japan. (author)

A preliminary assessment of earthquake ground shaking hazard at Yucca Mountain, Nevada and implications to the Las Vegas region

Energy Technology Data Exchange (ETDEWEB)

Wong, I.G.; Green, R.K.; Sun, J.I. [Woodward-Clyde Federal Services, Oakland, CA (United States); Pezzopane, S.K. [Geological Survey, Denver, CO (United States); Abrahamson, N.A. [Abrahamson (Norm A.), Piedmont, CA (United States); Quittmeyer, R.C. [Woodward-Clyde Federal Services, Las Vegas, NV (United States)

1996-12-31

As part of early design studies for the potential Yucca Mountain nuclear waste repository, the authors have performed a preliminary probabilistic seismic hazard analysis of ground shaking. A total of 88 Quaternary faults within 100 km of the site were considered in the hazard analysis. They were characterized in terms of their probability o being seismogenic, and their geometry, maximum earthquake magnitude, recurrence model, and slip rate. Individual faults were characterized by maximum earthquakes that ranged from moment magnitude (M{sub w}) 5.1 to 7.6. Fault slip rates ranged from a very low 0.00001 mm/yr to as much as 4 mm/yr. An areal source zone representing background earthquakes up to M{sub w} 6 1/4 = 1/4 was also included in the analysis. Recurrence for these background events was based on the 1904--1994 historical record, which contains events up to M{sub w} 5.6. Based on this analysis, the peak horizontal rock accelerations are 0.16, 0.21, 0.28, and 0.50 g for return periods of 500, 1,000, 2,000, and 10,000 years, respectively. In general, the dominant contributor to the ground shaking hazard at Yucca Mountain are background earthquakes because of the low slip rates of the Basin and Range faults. A significant effect on the probabilistic ground motions is due to the inclusion of a new attenuation relation developed specifically for earthquakes in extensional tectonic regimes. This relation gives significantly lower peak accelerations than five other predominantly California-based relations used in the analysis, possibly due to the lower stress drops of extensional earthquakes compared to California events. Because Las Vegas is located within the same tectonic regime as Yucca Mountain, the seismic sources and path and site factors affecting the seismic hazard at Yucca Mountain also have implications to Las Vegas. These implications are discussed in this paper.

Stable discretization of poroelasticity problems and efficient preconditioners for arising saddle point type matrices

Czech Academy of Sciences Publication Activity Database

Axelsson, Owe; Blaheta, Radim; Byczanski, Petr

2012-01-01

Roč. 15, č. 4 (2012), s. 191-207 ISSN 1432-9360 R&D Projects: GA MŠk ED1.1.00/02.0070 Institutional support: RVO:68145535 Keywords : poroelasticity * saddle point matrices * preconditioning * stability of discretization Subject RIV: BA - General Mathematics http://link.springer.com/article/10.1007/s00791-013-0209-0

Late thrusting extensional collapse at the mountain front of the northern Apennines (Italy)

Science.gov (United States)

Tavani, Stefano; Storti, Fabrizio; Bausã, Jordi; MuñOz, Josep A.

2012-08-01

Thrust-related anticlines exposed at the mountain front of the Cenozoic Appenninic thrust-and-fold belt share the presence of hinterlandward dipping extensional fault zones running parallel to the hosting anticlines. These fault zones downthrow the crests and the backlimbs with displacements lower than, but comparable to, the uplift of the hosting anticline. Contrasting information feeds a debate about the relative timing between thrust-related folding and beginning of extensional faulting, since several extensional episodes, spanning from early Jurassic to Quaternary, are documented in the central and northern Apennines. Mesostructural data were collected in the frontal anticline of the Sibillini thrust sheet, the mountain front in the Umbria-Marche sector of the northern Apennines, with the aim of fully constraining the stress history recorded in the deformed multilayer. Compressional structures developed during thrust propagation and fold growth, mostly locating in the fold limbs. Extensional elements striking about perpendicular to the shortening direction developed during two distinct episodes: before fold growth, when the area deformed by outer-arc extension in the peripheral bulge, and during a late to post thrusting stage. Most of the the extensional deformation occurred during the second stage, when the syn-thrusting erosional exhumation of the structures caused the development of pervasive longitudinal extensional fracturing in the crestal sector of the growing anticline, which anticipated the subsequent widespread Quaternary extensional tectonics.

Effects of saddle height on economy and anaerobic power in well-trained cyclists.

Science.gov (United States)

Peveler, Willard W; Green, James M

2011-03-01

In cycling, saddle height adjustment is critical for optimal performance and injury prevention. A 25-35° knee angle is recommended for injury prevention, whereas 109% of inseam, measured from floor to ischium, is recommended for optimal performance. Previous research has demonstrated that these 2 methods produce significantly different saddle heights and may influence cycling performance. This study compared performance between these 2 methods for determining saddle height. Subjects consisted of 11 well-trained (VO2max = 61.55 ± 4.72 ml·kg·min) male cyclists. Subjects completed a total of 8 performance trials consisting of a graded maximal protocol, three 15-minute economy trials, and 4 anaerobic power trials. Dependent measures for economy (VO2, heart rate, and rating of perceived exertion) and anaerobic power (peak power and mean power) were compared using repeated measures analysis of variance (α = 0.05). VO2 was significantly lower (reflecting greater economy) at a 25° knee angle (44.77 ± 6.40 ml·kg·min) in comparison to a 35° knee angle (45.22 ± 6.79 ml·kg·min) and 109% of inseam (45.98 ± 5.33 ml·kg·min). Peak power at a 25° knee angle (1,041.55 ± 168.72 W) was significantly higher in relation to 109% of inseam (1,002.05 ± 147.65 W). Mean power at a 25° knee angle (672.37 ± 90.21 W) was significantly higher in relation to a 35° knee angle (654.71 ± 80.67 W). Mean power was significantly higher at 109% of inseam (662.86 ± 79.72 W) in relation to a 35° knee angle (654.71 ± 80.67 W). Use of 109% of inseam fell outside the recommended 25-35° range 73% of the time. Use of 25° knee angle appears to provide optimal performance while keeping knee angle within the recommended range for injury prevention.

On the trajectories of CRL...LR...R orbits, their period-doubling cascades and saddle-node bifurcation cascades

International Nuclear Information System (INIS)

Cerrada, Lucia; San Martin, Jesus

2011-01-01

In this Letter, it is shown that from a two region partition of the phase space of a one-dimensional dynamical system, a p-region partition can be obtained for the CRL...LR...R orbits. That is, permutations associated with symbolic sequences are obtained. As a consequence, the trajectory in phase space is directly deduced from permutation. From this permutation other permutations associated with period-doubling and saddle-node bifurcation cascades are derived, as well as other composite permutations. - Research highlights: → Symbolic sequences are the usual topological approach to dynamical systems. → Permutations bear more physical information than symbolic sequences. → Period-doubling cascade permutations associated with original sequences are obtained. → Saddle-node cascade permutations associated with original sequences are obtained. → Composite permutations are derived.

Fluid flows due to earthquakes with reference to Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Davies, J.B.

1993-01-01

Yucca Mountain geohydrology is dominated by a deep water table in volcanic tuffa beds which are cut by numerous faults. Certain zones in these tuffas and most of the fault apertures are filled with a fine-grained calcitic cement. Earthquakes have occured in this region with the most recent being of magnitude 5.6 and at a distance of about 20 km. Earthquakes in western U.S.A. have been observed to cause fluid flows through and out of the crust of the Earth. These flows are concentrated along the faults with normal faulting producing the largest flows. An earthquake produces rapid pressure changes at and below the ground surface, thereby forcing flows of gas, water, slurries and dissolved salts. In order to examine the properties of flows produced by earthquakes, we simulate the phenomena using computer-based modeling. We investigate the effects of adults and high permeability zones on the pattern of flows induced by the earthquake. We demonstrate that faults act as conduits to the surface and that the higher the permeability of a zone, the more the flows will concentrate there. Numerical estimates of flow rates from these simulations compare favorably with data from observed flows due to earthquakes. Simple volumetric arguments demonstrate the ease with which fluids from the deep water table can reach the surface along fault conduits

Using Magnetics and Topography to Model Fault Splays of the Hilton Creek Fault System within the Long Valley Caldera

Science.gov (United States)

De Cristofaro, J. L.; Polet, J.

2017-12-01

The Hilton Creek Fault (HCF) is a range-bounding extensional fault that forms the eastern escarpment of California's Sierra Nevada mountain range, near the town of Mammoth Lakes. The fault is well mapped along its main trace to the south of the Long Valley Caldera (LVC), but the location and nature of its northern terminus is poorly constrained. The fault terminates as a series of left-stepping splays within the LVC, an area of active volcanism that most notably erupted 760 ka, and currently experiences continuous geothermal activity and sporadic earthquake swarms. The timing of the most recent motion on these fault splays is debated, as is the threat posed by this section of the Hilton Creek Fault. The Third Uniform California Earthquake Rupture Forecast (UCERF3) model depicts the HCF as a single strand projecting up to 12km into the LVC. However, Bailey (1989) and Hill and Montgomery-Brown (2015) have argued against this model, suggesting that extensional faulting within the Caldera has been accommodated by the ongoing volcanic uplift and thus the intracaldera section of the HCF has not experienced motion since 760ka.We intend to map the intracaldera fault splays and model their subsurface characteristics to better assess their rupture history and potential. This will be accomplished using high-resolution topography and subsurface geophysical methods, including ground-based magnetics. Preliminary work was performed using high-precision Nikon Nivo 5.C total stations to generate elevation profiles and a backpack mounted GEM GS-19 proton precession magnetometer. The initial results reveal a correlation between magnetic anomalies and topography. East-West topographic profiles show terrace-like steps, sub-meter in height, which correlate to changes in the magnetic data. Continued study of the magnetic data using Oasis Montaj 3D modeling software is planned. Additionally, we intend to prepare a high-resolution terrain model using structure-from-motion techniques

Repository site data report for unsaturated tuff, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Tien, P.L.; Updegraff, C.D.; Siegel, M.D.; Wahi, K.K.; Guzowski, R.V.

1985-11-01

The US Department of Energy is currently considering the thick sequences of unsaturated, fractured tuff at Yucca Mountain, on the southwestern boundary of the Nevada Test Site, as a possible candidate host rock for a nuclear-waste repository. Yucca Mountain is in one of the most arid areas in the United States. The site is within the south-central part of the Great Basin section of the Basin and Range physiographic province and is located near a number of silicic calderas of Tertiary age. Although localized zones of seismic activity are common throughout the province, and faults are present at Yucca Mountain, the site itself is basically aseismic. No data are available on the composition of ground water in the unsaturated zone at Yucca Mountain. It has been suggested that the composition is bounded by the compositions of water from wells USW-H3, UE25p-1, J-13, and snow or rain. There are relatively few data available from Yucca Mountain on the moisture content and saturation, hydraulic conductivity, and characteristic curves of the unsaturated zone. The available literature on thermomechanical properties of tuff does not always distinguish between data from the saturated zone and data from the unsaturated zone. Geochemical, hydrologic, and thermomechanical data available on the unsaturated tuffs of Yucca Mountain are tabulated in this report. Where the data are very sparse, they have been supplemented by data from the saturated zone or from areas other than Yucca Mountain. 316 refs., 58 figs., 37 tabs

Repository site data report for unsaturated tuff, Yucca Mountain, Nevada

Energy Technology Data Exchange (ETDEWEB)

Tien, P.L.; Updegraff, C.D.; Siegel, M.D.; Wahi, K.K.; Guzowski, R.V.

1985-11-01

The US Department of Energy is currently considering the thick sequences of unsaturated, fractured tuff at Yucca Mountain, on the southwestern boundary of the Nevada Test Site, as a possible candidate host rock for a nuclear-waste repository. Yucca Mountain is in one of the most arid areas in the United States. The site is within the south-central part of the Great Basin section of the Basin and Range physiographic province and is located near a number of silicic calderas of Tertiary age. Although localized zones of seismic activity are common throughout the province, and faults are present at Yucca Mountain, the site itself is basically aseismic. No data are available on the composition of ground water in the unsaturated zone at Yucca Mountain. It has been suggested that the composition is bounded by the compositions of water from wells USW-H3, UE25p-1, J-13, and snow or rain. There are relatively few data available from Yucca Mountain on the moisture content and saturation, hydraulic conductivity, and characteristic curves of the unsaturated zone. The available literature on thermomechanical properties of tuff does not always distinguish between data from the saturated zone and data from the unsaturated zone. Geochemical, hydrologic, and thermomechanical data available on the unsaturated tuffs of Yucca Mountain are tabulated in this report. Where the data are very sparse, they have been supplemented by data from the saturated zone or from areas other than Yucca Mountain. 316 refs., 58 figs., 37 tabs.

Alteration history studies in the Exploratory Studies Facility, Yucca Mountain, Nevada, USA

International Nuclear Information System (INIS)

Levy, S.S.; Chipera, S.J.; Norman, D.I.

1996-01-01

By mid-1995, the Exploratory Studies Facility (ESF) extended about 1. 1 km from Exile Hill westward toward Yucca Mountain, mostly within densely welded, devitrfied Tiva Canyon Tuff. Secondary mineral occurrences in this unit include breccia cements of mordenite, a fibrous zeolite, and vapor-phase deposits of silica, alkali feldspar, apatite, hollandite, amphibole, and zircon. Calcite is also a common secondary mineral in faults and fractures. Studies of water and gas contents in fluid inclusions in calcites from a fault in nonwelded tuff and a fracture in densely welded tuff suggest mineral deposition under transient locally saturated conditions. Calcite in the nonwelded tuff incorporated air from the unsaturated tuff adjacent to the fault. A highly altered interval within pre-Pah Canyon tuffs just above the top of the Topopah Spring Tuff may be a fossil fumarole or other hydrothermal feature associated with cooling pyroclastic deposits, overprinted by later zeolitic alteration. The observed quartz, cristobalite, opal-CT, and fluorite have been widely identified as products of syngenetic devitrification and vapor-phase alteration in and above the Topopah Spring Tuff. Smectite, also an abundant secondary mineral at the ESF site, has been observed elsewhere at this stratigraphic level. Zeolitic alteration of nonwelded tuffs above the Topopah Spring Tuff, as seen in the ESF, has also been noted in drill core and outcrop at northeastern Yucca Mountain. The hydrologic and geochemical conditions that favored zeolitization only in certain areas of this stratigraphic interval have yet to be determined

Investment decisions in the South African saddle horse industry / Johannes Hendrik Dreyer

OpenAIRE

Dreyer, Johannes Hendrik

2014-01-01

This study originated in the phenomenon that has been observed in the South African Saddle Horse Industry of substantial investments being made over time in the absence of obvious financial or economic reward. A literature study confirmed that, internationally, investment without obvious financial and economic rewards is not unknown and at the same time it was obvious that it is a rarely studied subject. From the literature study it was also evident that this phenomenon occurs ...

Late Cenozoic faulting and the stress state in the south-eastern segment of the Siberian platform

Directory of Open Access Journals (Sweden)

V. A. Sankov

2017-01-01

Full Text Available We have studied the structural geology and geomorphology of the fault zones in the junction area of the Angara-Lena uplift and the Predbaikalsky trough. We have analyzed faults and folds and reconstructed paleostresses for this junction area named the Irkutsk amphitheatre. Our study shows that syn-fold (Middle Paleozoic faults include thrusts, reverse faults and strike-slip faults with reverse components, that occurred due to compression from the neighbouring folded region. Recently, contrary to compression, faulting took place under the conditions of extension of the sedimentary cover: most of these recent faults have been classified as normal faults. In the Late Cenozoic, the platform cover was subjected to brittle and partly plicative deformation due to the NW–SE-trending extension that is most clearly observed in the adjacent Baikal rift. Thus, the divergent boundary between the Siberian block of the North Eurasian plate and the Transbaikalia block of the Amur plate is a zone of dynamic influence, which occupies the area considerably exceeding the mountainous region on the Siberian platform. Important factors of faulting are differentiated vertical movements of the blocks comprising the platform. Such vertical movements might have been related to displacements of brine volumes. In the Late Cenozoic basins, movements along separate faults took place in the Late Pleistocene – Holocene.

Mesozoic and Cenozoic uplift and exhumation of the Bogda Mountain, NW China: Evidence from apatite fission track analysis

Directory of Open Access Journals (Sweden)

Wenhao Tang

2015-07-01

Full Text Available Apatite fission track (AFT analysis on samples collected from a Paleozoic series is used to constrain the cooling history of the Bogda Mountain, northwest China. AFT ages range from 136.2 to 85.6 Ma and are younger than rock depositional ages and the mean confined track lengths (11.0–13.2 μm mostly showing unimodal distribution are shorten, indicating significant track-annealing. Thermal histories modeling based on the distribution of fission-track lengths combined with the regional geological data show that two rapid cooling phases occurred in the latest Jurassic–early Cretaceous and the Oligocene–Miocene. Those new data together with previous published data show that the AFT ages become younger from the southwest to northeast in the western Bogda Mountain and its adjacent areas. The fission-track ages of the southwest area are relatively older (>100 Ma, recording the earlier rapid uplift phase during the late Jurassic–Cretaceous, while the ages in the north piedmont of the Bogda Mountain (namely the northeast part are younger (<60 Ma, mainly reflecting the later rapid uplift phase in the Oligocene–Miocene. The trend of younger AFT ages towards the northeast might be explained by post-Cretaceous large-scale crustal tilting towards the southwest. In the thrust fault-dominated northern limbs of the Bogda Mountain, AFT ages reveal a discontinuous pattern with age-jumps across the major fault zones, showing a possible strata tilting across each thrust faults due to the thrust ramps during the Cenozoic. The two rapid uplift stages might be related to the accretion and collision in the southern margin of the Asian continent during the late Jurassic and late Cenozoic, respectively.

Structure in continuously cored, deep drill holes at Yucca Mountain, Nevada, with notes on calcite occurrence

International Nuclear Information System (INIS)

Carr, W.J.

1992-12-01

A study of more than 22,000 feet of core from five deep drill holes at Yucca Mountain, Nevada, provided data on the attitude and vertical distribution of faults and fractures, the sense of fault displacement, and the occurrence of calcite. The study was done mainly to look for evidence of fault flattening at depth, but no consistent downward decrease in dip of faults was found, and no increase in strata rotation was evident with increasing depth. In the two drill holes located near prominent faults that dip toward the holes (USW G-3 and G-2), an apparent increase in the frequency of faults occurs below the tuffs and lavas of Calico Hills. Some of this increase occurs in brittle lavas and flow breccias in the lower part of the volcanic section. In the two holes presumed to be relatively removed from the influence of important faults at depth, the vertical distribution of faults is relatively uniform. Calcite occurs mainly in two general zones, voids in welded portions of the Paintbrush Tuff, and in a deeper zone, mostly below 3,500 feet. Calcite is least abundant in USW G-4, which may reflect the fewer faults and fractures encountered in that drill hole

Saddle point solutions in Yang-Mills-dilaton theory

International Nuclear Information System (INIS)

Bizon, P.

1992-01-01

The coupling of a dilaton to the SU(2)-Yang-Mills field leads to interesting non-perturbative static spherically symmetric solutions which are studied by mixed analytical and numerical methods. In the abelian sector of the theory there are finite-energy magnetic and electric monopole solutions which saturate the Bogomol'nyi bound. In the nonabelian sector there exist a countable family of globally regular solutions which are purely magnetic but have zero Yang-Mills magnetic charge. Their discrete spectrum of energies is bounded from above by the energy of the abelian magnetic monopole with unit magnetic charge. The stability analysis demonstrates that the solutions are saddle points of the energy functional with increasing number of unstable modes. The existence and instability of these solutions are 'explained' by the Morse-theory argument recently proposed by Sudarsky and Wald. (author)

Quasar Microlensing at High Magnification and the Role of Dark Matter: Enhanced Fluctuations and Suppressed Saddle Points

Science.gov (United States)

Schechter, Paul L.; Wambsganss, Joachim

2002-12-01

Contrary to naive expectation, diluting the stellar component of the lensing galaxy in a highly magnified system with smoothly distributed ``dark'' matter increases rather than decreases the microlensing fluctuations caused by the remaining stars. For a bright pair of images straddling a critical curve, the saddle point (of the arrival time surface) is much more strongly affected than the associated minimum. With a mass ratio of smooth matter to microlensing matter of 4:1, a saddle point with a macromagnification of μ=9.5 will spend half of its time more than a magnitude fainter than predicted. The anomalous flux ratio observed for the close pair of images in MG 0414+0534 is a factor of 5 more likely than computed by Witt, Mao, & Schechter, if the smooth matter fraction is as high as 93%. The magnification probability histograms for macroimages exhibit a distinctly different structure that varies with the smooth matter content, providing a handle on the smooth matter fraction. Enhanced fluctuations can manifest themselves either in the temporal variations of a light curve or as flux ratio anomalies in a single epoch snapshot of a multiply imaged system. While the millilensing simulations of Metcalf & Madau also give larger anomalies for saddle points than for minima, the effect appears to be less dramatic for extended subhalos than for point masses. Moreover, microlensing is distinguishable from millilensing because it will produce noticeable changes in the magnification on a timescale of a decade or less.

Preconditioners for regularized saddle point problems with an application for heterogeneous Darcy flow problems

Czech Academy of Sciences Publication Activity Database

Axelsson, Owe; Blaheta, Radim; Byczanski, Petr; Karátson, J.; Ahmad, B.

2015-01-01

Roč. 280, č. 280 (2015), s. 141-157 ISSN 0377-0427 R&D Projects: GA MŠk ED1.1.00/02.0070 Institutional support: RVO:68145535 Keywords : preconditioners * heterogeneous coefficients * regularized saddle point Inner–outer iterations * Darcy flow Subject RIV: BA - General Mathematics Impact factor: 1.328, year: 2015 http://www.sciencedirect.com/science/article/pii/S0377042714005238

Saddle Slow Manifolds and Canard Orbits in [Formula: see text] and Application to the Full Hodgkin-Huxley Model.

Science.gov (United States)

Hasan, Cris R; Krauskopf, Bernd; Osinga, Hinke M

2018-04-19

Many physiological phenomena have the property that some variables evolve much faster than others. For example, neuron models typically involve observable differences in time scales. The Hodgkin-Huxley model is well known for explaining the ionic mechanism that generates the action potential in the squid giant axon. Rubin and Wechselberger (Biol. Cybern. 97:5-32, 2007) nondimensionalized this model and obtained a singularly perturbed system with two fast, two slow variables, and an explicit time-scale ratio ε. The dynamics of this system are complex and feature periodic orbits with a series of action potentials separated by small-amplitude oscillations (SAOs); also referred to as mixed-mode oscillations (MMOs). The slow dynamics of this system are organized by two-dimensional locally invariant manifolds called slow manifolds which can be either attracting or of saddle type.In this paper, we introduce a general approach for computing two-dimensional saddle slow manifolds and their stable and unstable fast manifolds. We also develop a technique for detecting and continuing associated canard orbits, which arise from the interaction between attracting and saddle slow manifolds, and provide a mechanism for the organization of SAOs in [Formula: see text]. We first test our approach with an extended four-dimensional normal form of a folded node. Our results demonstrate that our computations give reliable approximations of slow manifolds and canard orbits of this model. Our computational approach is then utilized to investigate the role of saddle slow manifolds and associated canard orbits of the full Hodgkin-Huxley model in organizing MMOs and determining the firing rates of action potentials. For ε sufficiently large, canard orbits are arranged in pairs of twin canard orbits with the same number of SAOs. We illustrate how twin canard orbits partition the attracting slow manifold into a number of ribbons that play the role of sectors of rotations. The upshot is that we

Apatite fission track evidence on the uplifting of eastern Kunlun mountains

International Nuclear Information System (INIS)

Yuang Wanming; Dong Jinquan; Tang Yunhui; Wang Shicheng

2004-01-01

A series of samples were collected from about south-north section through Buqingshan and Dulan, eastern Kunlun mountains, China. The 41 apatite fission track ages (FTA) of these samples lie between 25.2 and 130.4 Ma, all of the apatite fission track ages are significantly younger than the host rocks. There are similar evolution trends for Middle-Kunlun zone and North-Kunlun zone, i.e. the FTA becomes less with slow increase of elevations and their uplifting rates are about 2.22 m/Ma. Differently, the FTA in South-Kunlun zone positively correlates to elevation, decreasing 11 m/Ma. It may be shown that South-Kunlun fault play a different and/or more important role on incontinent evolution than Middle-Kunlun fault. (author)

Modeling studies of mountain-scale radionuclide transport in the unsaturated zone at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Moridis, George J.; Seol, Yongkoo; Wu, Yu-Shu

2003-01-01

We investigate radionuclide transport from a high-level nuclear waste repository to be situated in the unsaturated zone (UZ) at Yucca Mountain (YM), Nevada. Several radioactive solutes (that cover the range of sorption behavior) and colloids of various sizes are studied. The results of the study indicate the importance of the subsurface geology and site hydrology, i.e., the presence of faults (they dominate and control transport), fractures (the main migration pathways), and the relative distribution of zeolitic and vitric tuffs. The effects of the climatic conditions, diffusion, and sorption (for solutes) or infiltration (for colloids) onto the matrix are discussed. The influence of the colloid size on transport is also investigated

Near Fault Observatories: multidisciplinary research infrastructures, high resolution data and scientific products available through dedicated services implemented within the EPOS-IP project

Science.gov (United States)

Festa, Gaetano; Chiaraluce, Lauro; Ergintav, Semih; Bernard, Pascal; Clinton, John; Marmureanu, Alexandru; Tataru, Dragos; Vogfjord, Kristin

2017-04-01

Near Fault Observatories (NFOs) are innovative research infrastructures based on dense, state of the art networks of multi-parametric sensors that continuously monitor the underlying Earth instability processes over a broad time interval. They aim at understanding the physical/chemical processes responsible for earthquakes and faulting and tracking their evolution over time by enabling advancements in ground shaking prediction. EPOS-IP is aimed at contributing in creating and harmonizing data and products distributors from seven NFOs, operating on different tectonic regimes and different areas of Europe. They include plate boundary systems at South Iceland Seismic Zone, the Marmara Sea and the Corinth rift. In mountain settings, NFOs monitor the Alto Tiberina and Irpinia faults in the Apennine mountain range, the Valais region in the Alps, and the Vrancea fault in the Carpathian Mountains. They monitor diverse faulting mechanisms (strike-slip, normal and thrust), high to low angle faults, shallow and deep faults, as well as regions with fast and slow strain rate accumulation. The focus of the observatories varies, ranging from small- to large-scale seismicity and includes the role of different parameters such as fluid playing in fault initiation, the internal structure of fault systems, site effects and derived processes such as earthquake generated landslides and tsunamis. In response to their specific objectives, the NFOs operate a diverse set of monitoring instrumentation using seismic, deformation, strain, geochemical and electromagnetic equipment. Since NFO methodological approach is based on extremely dense networks and less common instruments deserving multi-parameter data description, a main goal of this group is to build inclusive and harmonised services supporting the installation over the next decade of tens of near-fault observatories monitoring active faults in different tectonic environments in Europe. The NFO Thematic Core Service (TCS) relies on

Purires and Picagres faults and its relationship with the 1990 Puriscal seismic sequence

International Nuclear Information System (INIS)

Montero, Walter; Rojas, Wilfredo

2014-01-01

The system of active faults in the region between the southern flank of the Montes del Aguacate and the northwest flank of the Talamanca mountain range was re-evaluated and defined in relation to the seismic activity that occurred between the end of March 1990 and the beginning of 1991. Aerial photographs of different scales of the Instituto Geografico Nacional de Costa Rica, aerial photographs of scale 1: 40000 of the TERRA project, of the Centro Nacional Geoambiental and infrared photos of scale 1: 40000 of the Mission CARTA 2003, of the Programa Nacional de Investigaciones Aerotransportadas y Sensores Remotos (PRIAS) were reviewed. Morphotectonic, structural and geological information related to the various faults was obtained with field work. A set of faults within the study area were determined with the neotectonic investigation. Several of these faults continue outside the zone both to the northwest within the Montes del Aguacate, and to the southeast to the NW foothills of the Cordillera de Talamanca. The superficial focus seismicity (<20 km), which occurred in the Puriscal area during 1990, was revised from previous studies, whose base information comes from the Red Sismologica Nacional (RSN, UCR-ICE). The relationship between the superficial seismic sequence and the defined faults was determined, allowing to conclude that the main seismic sources that originated the seismicity were the Purires and Picagres faults. A minor seismicity was related to the faults Jaris, Bajos de Jorco, Zapote and Junquillo [es

Fault morphology of the lyo Fault, the Median Tectonic Line Active Fault System

OpenAIRE

後藤, 秀昭

1996-01-01

In this paper, we investigated the various fault features of the lyo fault and depicted fault lines or detailed topographic map. The results of this paper are summarized as follows; 1) Distinct evidence of the right-lateral movement is continuously discernible along the lyo fault. 2) Active fault traces are remarkably linear suggesting that the angle of fault plane is high. 3) The lyo fault can be divided into four segments by jogs between left-stepping traces. 4) The mean slip rate is 1.3 ～ ...

Active normal faults and submarine landslides in the Keelung Shelf off NE Taiwan

Directory of Open Access Journals (Sweden)

Ching-Hui Tsai

2018-01-01

Full Text Available The westernmost Okinawa Trough back-arc basin is located to the north of the Ryukyu islands and is situated above the northward dipping Ryukyu subducted slab. In the northern continental margin of the Okinawa Trough, the continental slope between the Keelung Valley and the Mein-Hua Submarine Canyon shows a steep angle and future slope failures are expected. The question is how slope failures will proceed? A sudden deep-seated slump or landslide would probably cause local tsunami and hit northern coast of Taiwan. To understand the probable submarine landslides, we conducted multi-channel seismic reflection, sub-bottom profilers, and multi-beam bathymetry surveys off NE Taiwan. Two general trends of shallow crustal faults are observed. The NE-SW trending faults generally follow the main structural trend of the Taiwan mountain belt. These faults are products of inversion tectonics of reverse faults from the former collisional thrust faults to post-collisional normal faults. Another trend of roughly E-W faults is consistent with the current N-S extension of the southern Okinawa Trough. The fault offsets in the eastern portion of the study area are more pronounced. No obvious basal surface of sliding is found beneath the continental margin. We conclude that the movement of the submarine landslides in the Keelung Shelf off northeastern Taiwan could be in a spread type. The submarine landslides mainly occur in the continental slope area and it is more obvious in the east than in the west of the Keelung Shelf.

Combined analysis of surface reflection imaging and vertical seismic profiling at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Daley, T.M.; Majer, E.L.; Karageorgi, E.

1994-08-01

This report presents results from surface and borehole seismic profiling performed by the Lawrence Berkeley Laboratory (LBL) on Yucca Mountain. This work was performed as part of the site characterization effort for the potential high-level nuclear waste repository. Their objective was to provide seismic imaging from the near surface (200 to 300 ft. depth) to the repository horizon and below, if possible. Among the issues addressed by this seismic imaging work are location and depth of fracturing and faulting, geologic identification of reflecting horizons, and spatial continuity of reflecting horizons. The authors believe their results are generally positive, with tome specific successes. This was the first attempt at this scale using modem seismic imaging techniques to determine geologic features on Yucca Mountain. The principle purpose of this report is to present the interpretation of the seismic reflection section in a geologic context. Three surface reflection profiles were acquired and processed as part of this study. Because of environmental concerns, all three lines were on preexisting roads. Line 1 crossed the mapped surface trace of the Ghost Dance fault and it was intended to study the dip and depth extent of the fault system. Line 2 was acquired along Drill Hole wash and was intended to help the ESF north ramp design activities. Line 3 was acquired along Yucca Crest and was designed to image geologic horizons which were thought to be less faulted along the ridge. Unfortunately, line 3 proved to have poor data quality, in part because of winds, poor field conditions and limited time. Their processing and interpretation efforts were focused on lines 1 and 2 and their associated VSP studies

A revised Lithostratigraphic Framework for the Southern Yucca Mountain Area, Nye County, Nevada

International Nuclear Information System (INIS)

R.W. Spengler; F.M. Byers; R.P. Dickerson

2006-01-01

An informal, revised lithostratigraphic framework for the southern Yucca Mountain area, Nevada has been developed to accommodate new information derived from subsurface investigations of the Nye County Early Warning Drilling Program. Lithologies penetrated by recently drilled boreholes at locations between Stagecoach Road and Highway 95 in southern Nye County include Quaternary and Pliocene alluvium and alluvial breccia, Miocene pyroclastic flow deposits and intercalated lacustrine siltstone and claystone sequences, early Miocene to Oligocene pre-volcanic sedimentary rocks, and Paleozoic strata. Of the 37 boreholes currently drilled, 21 boreholes have sufficient depth, spatial distribution, or traceable pyroclastic flow, pyroclastic fall, and reworked tuff deposits to aid in the lateral correlation of lithostrata. Medial and distal parts of regional pyroclastic flow deposits of Miocene age can be correlated with the Timber Mountain, Paintbrush, Crater Flat, and Tram Ridge Groups. Rocks intercalated between these regional pyroclastic flow deposits are substantially thicker than in the central part of Yucca Mountain, particularly near the downthrown side of major faults and along the southern extent of exposures at Yucca Mountain

Geologic map of the Hiller Mountain Quadrangle, Clark County, Nevada, and Mohave County, Arizona

Science.gov (United States)

Howard, Keith A.; Hook, Simon; Phelps, Geoffrey A.; Block, Debra L.

2003-01-01

Map Scale: 1:24,000 Map Type: colored geologic map The Hiller Mountains Quadrangle straddles Virgin Canyon in the eastern part of Lake Mead. Proterozoic gneisses and granitoid rocks underlie much of the quadrangle. They are overlain by upper Miocene basin-filling deposits of arkosic conglomerate, basalt, and the overlying Hualapai Limestone. Inception of the Colorado River followed deposition of the Hualapai Limestone and caused incision of the older rocks. Fluvial gravel deposits indicate various courses of the early river across passes through highlands of the Gold Butte-Hiller Mountains-White Hills structural block. Faults and tilted rocks in the quadrangle record tectonic extension that climaxed in middle Miocene time.

Constraining fault interpretation through tomographic velocity gradients: application to northern Cascadia

Directory of Open Access Journals (Sweden)

K. Ramachandran

2012-02-01

Full Text Available Spatial gradients of tomographic velocities are seldom used in interpretation of subsurface fault structures. This study shows that spatial velocity gradients can be used effectively in identifying subsurface discontinuities in the horizontal and vertical directions. Three-dimensional velocity models constructed through tomographic inversion of active source and/or earthquake traveltime data are generally built from an initial 1-D velocity model that varies only with depth. Regularized tomographic inversion algorithms impose constraints on the roughness of the model that help to stabilize the inversion process. Final velocity models obtained from regularized tomographic inversions have smooth three-dimensional structures that are required by the data. Final velocity models are usually analyzed and interpreted either as a perturbation velocity model or as an absolute velocity model. Compared to perturbation velocity model, absolute velocity models have an advantage of providing constraints on lithology. Both velocity models lack the ability to provide sharp constraints on subsurface faults. An interpretational approach utilizing spatial velocity gradients applied to northern Cascadia shows that subsurface faults that are not clearly interpretable from velocity model plots can be identified by sharp contrasts in velocity gradient plots. This interpretation resulted in inferring the locations of the Tacoma, Seattle, Southern Whidbey Island, and Darrington Devil's Mountain faults much more clearly. The Coast Range Boundary fault, previously hypothesized on the basis of sedimentological and tectonic observations, is inferred clearly from the gradient plots. Many of the fault locations imaged from gradient data correlate with earthquake hypocenters, indicating their seismogenic nature.

Strontium isotope geochemistry of soil and playa deposits near Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Marshall, B.D.; Mahan, S.A.

1994-01-01

The isotopic composition of strontium contained in the carbonate fractions of soils provides an excellent tracer which can be used to test models for their origin. This paper reports data on surface coatings and cements, eolian sediments, playas and alluvial fan soils which help to constrain a model for formation of the extensive calcretes and fault infillings in the Yucca Mountain region. The playas contain carbonate with a wide range of strontium compositions; further work will be required to fully understand their possible contributions to the pedogenic carbonate system. Soils from an alluvial fan to the west of Yucca Mountain show that only small amounts of strontium are derived from a fan draining a carbonate terrane have strontium component. Although much evidence points to an eolian source for at least some of the strontium in the pedogenic carbonates near Yucca Mountain, an additional component or past variation of strontium composition in the eolian source is required to model the pedogenic carbonate system

Architecture of a low-angle normal fault zone, southern Basin and Range (SE California)

Science.gov (United States)

Goyette, J. A.; John, B. E.; Campbell-Stone, E.; Stunitz, H.; Heilbronner, R.; Pec, M.

2009-12-01

Exposures of the denuded Cenozoic detachment fault system in the southern Sacramento Mountains (SE California) delimit the architecture of a regional low-angle normal fault, and highlight the evolution of these enigmatic faults. The fault was initiated ~23 Ma in quartzo-feldspathic basement gneiss and granitoids at a low-angle (2km, and amplitudes up to 100m. These corrugations are continuous along their hinges for up to 3.6 km. Damage zone fracture intensity varies both laterally, and perpendicular to the fault plane (over an area of 25km2), decreasing with depth in the footwall, and varies as a function of lithology and proximity to corrugation walls. Deformation is concentrated into narrow damage zones (100m) are found in areas where low-fracture intensity horses are corralled by sub-horizontal zones of cataclasite (up to 8m) and thick zones of epidote (up to 20cm) and silica-rich alteration (up to 1m). Sub-vertical shear and extension fractures, and sub-horizontal shear fractures/zones dominate the NE side of the core complex. In all cases, sub-vertical fractures verge into or are truncated by low-angle fractures that dominate the top of the damage zone. These low-angle fractures have an antithetic dip to the detachment fault plane. Some sub-vertical fractures become curviplanar close to the fault, where they are folded into parallelism with the sub-horizontal fault surface in the direction of transport. These field data, corroborated by ongoing microstructural analyses, indicate fault activity at a low angle accommodated by a variety of deformation mechanisms dependent on lithology, timing, fluid flow, and fault morphology.

Flood-inundation maps for the Saddle River from Rochelle Park to Lodi, New Jersey, 2012

Science.gov (United States)

Hoppe, Heidi L.; Watson, Kara M.

2012-01-01

Digital flood-inundation maps for a 2.75-mile reach of the Saddle River from 0.2 mile upstream from the Interstate 80 bridge in Rochelle Park to 1.5 miles downstream from the U.S. Route 46 bridge in Lodi, New Jersey, were created by the U.S. Geological Survey (USGS) in cooperation with the New Jersey Department of Environmental Protection (NJDEP). The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage at Saddle River at Lodi, New Jersey (station 01391500). Current conditions for estimating near real-time areas of inundation using USGS streamgage information may be obtained on the Internet at http://waterdata.usgs.gov/nwis/uv?site_no=01391500. The National Weather Service (NWS) forecasts flood hydrographs at many places that are often collocated with USGS streamgages. NWS-forecasted peak-stage information may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. In this study, flood profiles were computed for the stream reach by means of a one-dimensional step-backwater model. The model was calibrated using the most current stage-discharge relations at the Saddle River at Lodi, New Jersey streamgage and documented high-water marks from recent floods. The hydraulic model was then used to determine 11 water-surface profiles for flood stages at the Saddle River streamgage at 1-ft intervals referenced to the streamgage datum, North American Vertical Datum of 1988 (NAVD 88), and ranging from bankfull, 0.5 ft below NWS Action Stage, to the extent of the stage-discharge rating, which is approximately 1 ft higher than the highest recorded water level at the streamgage. Action Stage is the stage which when reached by a rising stream the NWS or a partner needs to take some type of mitigation action in

Modeling fluid flow and heat transfer at Basin and Range faults: preliminary results for Leach hot springs, Nevada

Science.gov (United States)

López, Dina L.; Smith, Leslie; Storey, Michael L.; Nielson, Dennis L.

1994-01-01

The hydrothermal systems of the Basin and Range Province are often located at or near major range bounding normal faults. The flow of fluid and energy at these faults is affected by the advective transfer of heat and fluid from an to the adjacent mountain ranges and valleys, This paper addresses the effect of the exchange of fluid and energy between the country rock, the valley fill sediments, and the fault zone, on the fluid and heat flow regimes at the fault plane. For comparative purposes, the conditions simulated are patterned on Leach Hot Springs in southern Grass Valley, Nevada. Our simulations indicated that convection can exist at the fault plane even when the fault is exchanging significant heat and fluid with the surrounding country rock and valley fill sediments. The temperature at the base of the fault decreased with increasing permeability of the country rock. Higher groundwater discharge from the fault and lower temperatures at the base of the fault are favored by high country rock permabilities and fault transmissivities. Preliminary results suggest that basal temperatures and flow rates for Leach Hot Springs can not be simulated with a fault 3 km deep and an average regional heat flow of 150 mW/m2 because the basal temperature and mass discharge rates are too low. A fault permeable to greater depths or a higher regional heat flow may be indicated for these springs.

Exotic Homoclinic Surface of a Saddle-Node Limit Cycle in a Leech Neuron Model

Science.gov (United States)

Yooer, Chi-Feng; Wei, Fang; Xu, Jian-Xue; Zhang, Xin-Hua

2011-03-01

We carry out numerical and theoretical investigations on the global unstable invariant set (manifold) of a saddle-node limit cycle in a leech heart interneuron model. The corresponding global bifurcation is accompanied by an explosion of secondary bifurcations of limit cycles and the emergence of loop-shaped bifurcation structures. The dynamical behaviors of the trajectories of the invariant set are very complicated and can only be partially explained by existing theories.

Paleoearthquakes at Frazier Mountain, California delimit extent and frequency of past San Andreas Fault ruptures along 1857 trace

Science.gov (United States)

Scharer, Katherine M.; Weldon, Ray; Streig, Ashley; Fumal, Thomas

2014-01-01

Large earthquakes are infrequent along a single fault, and therefore historic, well-characterized earthquakes exert a strong influence on fault behavior models. This is true of the 1857 Fort Tejon earthquake (estimated M7.7–7.9) on the southern San Andreas Fault (SSAF), but an outstanding question is whether the 330 km long rupture was typical. New paleoseismic data for six to seven ground-rupturing earthquakes on the Big Bend of the SSAF restrict the pattern of possible ruptures on the 1857 stretch of the fault. In conjunction with existing sites, we show that over the last ~650 years, at least 75% of the surface ruptures are shorter than the 1857 earthquake, with estimated rupture lengths of 100 to <300 km. These results suggest that the 1857 rupture was unusual, perhaps leading to the long open interval, and that a return to pre-1857 behavior would increase the rate of M7.3–M7.7 earthquakes.

Design of a three-dimensional site-scale model for the unsaturated zone at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Wittwer, C.S.; Bodvarsson, G.S.; Chornack, M.P.; Flint, A.L.; Lewis, B.D.; Spengler, R.W.; Flint, L.E.; Rautman, C.A.

1992-01-01

A three-dimensional model of moisture flow within the unsaturated zone at Yucca Mountain is being developed. This site-scale model covers an area of about 30 km 2 and is bounded by major faults to the east and west. A detailed numerical grid has been developed based on location of boreholes, different infiltration zones, hydrogeological units and their outcrops, major faults, and water level data. Different maps, such as contour maps and isopachs maps, are presented for the different infiltration zones, and for the base of the Tiva Canyon, the Paintbrush, and the Topopah Spring hydrogeological units

A computational/directional solidification method to establish saddle points on the Mg-Al-Ca liquidus

International Nuclear Information System (INIS)

Cao Hongbo; Zhang Chuan; Zhu Jun; Cao Guoping; Kou Sindo; Schmid-Fetzer, Rainer; Chang, Y. Austin

2008-01-01

We established two saddle point maxima, L + α(Mg) + C14 and L + α(Mg) + C36, on the monovariant liquidus, calculated from a previously presented thermodynamic description, by characterizing the microstructures of several directionally solidified alloys in the near-solidification front zone, the mushy zone, and the steady-state zone using optical microscopy, scanning electron microscopy and transmission electron microscopy

Orogenesis of the Oman Mountains - a new geodynamic model based on structural geology, plate reconstructions and thermochronology

Science.gov (United States)

Grobe, Arne; Virgo, Simon; von Hagke, Christoph; Ralf, Littke; Urai, Janos L.

2017-04-01

Ophiolite obduction is an integral part of mountain building in many orogens. However, because the obduction stage is usually overprinted by later tectonic events, obduction geodynamics and its influence on orogenesis are often elusive. The best-preserved ophiolite on Earth is the Semail Ophiolite, Oman Mountains. 350 km of ophiolite and the entire overthrusted margin sequence are exposed perpendicular to the direction of obduction along the northeastern coast of the Sultanate of Oman. Despite excellent exposure, it has been debated whether early stages of obduction included formation of a micro-plate, or if the Oman Mountains result from collision of two macro-plates (e.g. Breton et al., 2004). Furthermore, different tectonic models for the Oman Mountains exist, and it is unclear how structural and tectonic phases relate to geodynamic context. Here we present a multidisciplinary approach to constrain orogenesis of the Oman Mountains. To this end, we first restore the structural evolution of the carbonate platform in the footwall of the Semail ophiolite. Relative ages of nine structural generations can be distinguished, based on more than 1,500 vein and fault overprintings. Top-to-S overthrusting of the Semail ophiolite is witnessed by three different generations of bedding confined veins in an anticlockwise rotating stress field. Rapid burial induced the formation of overpressure cells, and generation and migration of hydrocarbons (Fink et al., 2015; Grobe et al., 2016). Subsequent tectonic thinning of the ophiolite took place above a top-to-NNE crustal scale, ductile shear zone, deforming existing veins and forming a cleavage in clay-rich layers. Ongoing extension formed normal- to oblique-slip faults and horst-graben structures. This was followed by NE-SW oriented ductile shortening, the formation of the Jebel Akhdar anticline, potentially controlled by the positions of the horst-graben structures. Exhumation in the Cenozoic was associated with low angle normal

Tritium, carbon-14, and iodine-129 as indicators for localized vertical recharge along an anticline in the Columbia River Basalts using a decay-corrected mixing model

International Nuclear Information System (INIS)

Hall, S.H.; Johnson, V.G.; Early, T.O.

1987-11-01

Tritium, 14 C, and 129 I in groundwater samples are used to demonstrate vertical recharge and measure flow velocity in the fractured and faulted Umtanum Ridge-Gable Mountain acticline, within the Columbia River Basalts, at a sampling site about 6 mi northeast of the proposed high-level nuclear waste repository at the Hanford Site, Washington State. Mixing model calculations yield an apparent downward migration rate of 15 to 19 ft/yr through a sequence of aquifers in the Wanapum Basalt that range in depth from 698 to 1373 ft. Estimates of the vertical flow rate in the overlying Saddle Mountains Basalt are somewhat higher. Hydrographs from neighboring wells, hydrostatic heads, pump test data, and the chemical composition of groundwater samples from the sampling well are consistent with interaquifer communication. Some hydrologic evidence from aquifers in this region suggests that, in the past, flow may have been upward. This possible reversal of flow may be associated with water table mounding in the unconfined aquifer, caused by waste disposal activities at the Hanford Site since World War II. 17 refs., 12 figs., 3 tabs

Using a new saddle model for echinotherapy therapy.

Directory of Open Access Journals (Sweden)

Carlos Cesar Santín Alfaro

2014-09-01

Full Text Available A descriptive study with experimental design was done, having as an objective to elaborate a new riding saddle model in the Provincial Laboratory of Technical Orthopaedics in the province of Sancti Spiritus for the Echinotherapy´s treatment in disable patients that still assisting to this kind of alternative therapy having the necessity of obtaining the frame according to the adequate characteristics and adjusting to the requirements of the qualified staff that takes care of this task taking into consideration that for the rehabilitation of these children they should be closer to the horse skin. The frame was not made with the row materials of normal chair but with the one adequate in our Laboratory. Some important characteristics were developed in this kind of therapy, and was analyzed the characteristics of the frame use give to patients, offering an immediate solution to their problems in order to solve this difficulty in our province.

Fault tolerant control based on active fault diagnosis

DEFF Research Database (Denmark)

Niemann, Hans Henrik

2005-01-01

An active fault diagnosis (AFD) method will be considered in this paper in connection with a Fault Tolerant Control (FTC) architecture based on the YJBK parameterization of all stabilizing controllers. The architecture consists of a fault diagnosis (FD) part and a controller reconfiguration (CR......) part. The FTC architecture can be applied for additive faults, parametric faults, and for system structural changes. Only parametric faults will be considered in this paper. The main focus in this paper is on the use of the new approach of active fault diagnosis in connection with FTC. The active fault...... diagnosis approach is based on including an auxiliary input in the system. A fault signature matrix is introduced in connection with AFD, given as the transfer function from the auxiliary input to the residual output. This can be considered as a generalization of the passive fault diagnosis case, where...

Determination of shell correction energies at saddle point using pre-scission neutron multiplicities

International Nuclear Information System (INIS)

Golda, K.S.; Saxena, A.; Mittal, V.K.; Mahata, K.; Sugathan, P.; Jhingan, A.; Singh, V.; Sandal, R.; Goyal, S.; Gehlot, J.; Dhal, A.; Behera, B.R.; Bhowmik, R.K.; Kailas, S.

2013-01-01

Pre-scission neutron multiplicities have been measured for 12 C + 194, 198 Pt systems at matching excitation energies at near Coulomb barrier region. Statistical model analysis with a modified fission barrier and level density prescription have been carried out to fit the measured pre-scission neutron multiplicities and the available evaporation residue and fission cross sections simultaneously to constrain statistical model parameters. Simultaneous fitting of the pre-scission neutron multiplicities and cross section data requires shell correction at the saddle point

Mountains, glaciers, and mines—The geological story of the Blue River valley, Colorado, and its surrounding mountains

Science.gov (United States)

Kellogg, Karl; Bryant, Bruce; Shroba, Ralph R.

2016-02-10

This report describes, in a nontechnical style, the geologic history and mining activity in the Blue River region of Colorado, which includes all of Summit County. The geologic story begins with the formation of ancient basement rocks, as old as about 1700 million years, and continues with the deposition of sedimentary rocks on a vast erosional surface beginning in the Cambrian Period (about 530 million years ago). This deposition was interrupted by uplift of the Ancestral Rocky Mountains during the late Paleozoic Era (about 300 million years ago). The present Rocky Mountains began to rise at the close of the Mesozoic Era (about 65 million years ago). A few tens of millions years ago, rifting began to form the Blue River valley; a major fault along the east side of the Gore Range dropped the east side down, forming the present valley. The valley once was filled by sediments and volcanic rocks that are now largely eroded. During the last few hundred-thousand years, at least two periods of glaciation sculpted the mountains bordering the valley and glaciers extended down the Blue River valley as far south as present Dillon Reservoir. Discovery of deposits of gold, silver, copper, and zinc in the late 1800s, particularly in the Breckenridge region, brought an influx of early settlers. The world-class molybdenum deposit at Climax, mined since the First World War, reopened in 2012 after a period of closure.

Saddle-splay elasticity of nematic structures confined to a cylindrical capillary

International Nuclear Information System (INIS)

Kralj, S.; Zumer, S.

1995-01-01

The stability of nematic structures within a cylindrical capillary whose wall exhibits a homeotropic boundary condition is studied. The structures are obtained numerically from Euler-Lagrange equations resulting from the minimization of the Frank free energy functional. Stability diagrams are presented showing dependence on elastic properties, surface anchoring, and external transversal field strength. Emphasis is given to the effects of the saddle-splay elastic constant (K 24 ), which plays an important role in the weak anchoring regime. A new structure---the planar polar structure with two line defects---is predicted. It is shown that it is stable in a finite interval of the external field strength in the strong anchoring regime

Using hydraulic head, chloride and electrical conductivity data to distinguish between mountain-front and mountain-block recharge to basin aquifers

Science.gov (United States)

Bresciani, Etienne; Cranswick, Roger H.; Banks, Eddie W.; Batlle-Aguilar, Jordi; Cook, Peter G.; Batelaan, Okke

2018-03-01

Numerous basin aquifers in arid and semi-arid regions of the world derive a significant portion of their recharge from adjacent mountains. Such recharge can effectively occur through either stream infiltration in the mountain-front zone (mountain-front recharge, MFR) or subsurface flow from the mountain (mountain-block recharge, MBR). While a thorough understanding of recharge mechanisms is critical for conceptualizing and managing groundwater systems, distinguishing between MFR and MBR is difficult. We present an approach that uses hydraulic head, chloride and electrical conductivity (EC) data to distinguish between MFR and MBR. These variables are inexpensive to measure, and may be readily available from hydrogeological databases in many cases. Hydraulic heads can provide information on groundwater flow directions and stream-aquifer interactions, while chloride concentrations and EC values can be used to distinguish between different water sources if these have a distinct signature. Such information can provide evidence for the occurrence or absence of MFR and MBR. This approach is tested through application to the Adelaide Plains basin, South Australia. The recharge mechanisms of this basin have long been debated, in part due to difficulties in understanding the hydraulic role of faults. Both hydraulic head and chloride (equivalently, EC) data consistently suggest that streams are gaining in the adjacent Mount Lofty Ranges and losing when entering the basin. Moreover, the data indicate that not only the Quaternary aquifers but also the deeper Tertiary aquifers are recharged through MFR and not MBR. It is expected that this finding will have a significant impact on the management of water resources in the region. This study demonstrates the relevance of using hydraulic head, chloride and EC data to distinguish between MFR and MBR.

Using hydraulic head, chloride and electrical conductivity data to distinguish between mountain-front and mountain-block recharge to basin aquifers

Directory of Open Access Journals (Sweden)

E. Bresciani

2018-03-01

Full Text Available Numerous basin aquifers in arid and semi-arid regions of the world derive a significant portion of their recharge from adjacent mountains. Such recharge can effectively occur through either stream infiltration in the mountain-front zone (mountain-front recharge, MFR or subsurface flow from the mountain (mountain-block recharge, MBR. While a thorough understanding of recharge mechanisms is critical for conceptualizing and managing groundwater systems, distinguishing between MFR and MBR is difficult. We present an approach that uses hydraulic head, chloride and electrical conductivity (EC data to distinguish between MFR and MBR. These variables are inexpensive to measure, and may be readily available from hydrogeological databases in many cases. Hydraulic heads can provide information on groundwater flow directions and stream–aquifer interactions, while chloride concentrations and EC values can be used to distinguish between different water sources if these have a distinct signature. Such information can provide evidence for the occurrence or absence of MFR and MBR. This approach is tested through application to the Adelaide Plains basin, South Australia. The recharge mechanisms of this basin have long been debated, in part due to difficulties in understanding the hydraulic role of faults. Both hydraulic head and chloride (equivalently, EC data consistently suggest that streams are gaining in the adjacent Mount Lofty Ranges and losing when entering the basin. Moreover, the data indicate that not only the Quaternary aquifers but also the deeper Tertiary aquifers are recharged through MFR and not MBR. It is expected that this finding will have a significant impact on the management of water resources in the region. This study demonstrates the relevance of using hydraulic head, chloride and EC data to distinguish between MFR and MBR.

The characteristics of the western extension of the Karakax fault in NW Tibet and its tectonic implications

Science.gov (United States)

Ge, C.; Liu, D.; Li, H.; Zheng, Y.; Pan, J.

2017-12-01

The Karakax strike-slip fault, located in northwest Tibet, is a mature deformation belt with a long-time evolutionary history, which is also active at present and plays an important role in the tectonic deformation of the northwestern Tibetan Plateau. Nowadays, most geologists consider that the Karakax fault is generally east-west striking along the Karakax river valley, and northwest striking until to the Tashkorgan in the Mazar area. However, an ENE-WSW fault was identified at the Mazar area, which sited at the bend of the Karakax fault, we named this fault as the Matar fault. Via the detailed geological survey, the similar geometry and kinematic characteristics were identified between the Karakax and Matar faults: (1) The similar fault zone scale(Karakax:90 300m; Matar:100 220m); (2) The similar preferred orientation (nearly EW) of the stretching lineations and foliations; (3) All the fault planes of the both faults have a high dip angle and is nearly EW striking; (4) Lots of ductile deformations, such as σ-type quartz rotational mortar, S-C fabric, symmetric drag fold and so on, indicated that the Matar fault is a right-lateral strike-slip and thrust fault during the early ductile deformation stage; (5) the deluvium, sheared by Matar fault, indicated that the Matar fault has already transformed into a left-lateral strike-slip fault during the later brittle deformation stage. All the above showed that the Matar fault has a similar geometry and kinematic characteristics with the Karakax fault, and the former is the probable the western extension of the latter. Moreover, the form of the Karakax-Matar fault may had an impact to the geomorphology of the west Kunlun-Pamir area, such as the strike of the moutains and faults. considering the age of west Kunlun mountains uplifting and Karakax fault activating, we regard that the Matar fault (the westward extension of Karakax fault) may contributes much in forming the modern geomorphology features of the west Kunlun

Geohydrologic data and models of Rainier Mesa and their implications to Yucca Mountain

International Nuclear Information System (INIS)

Wang, J.S.Y.; Cook, N.G.W.; Wollenberg, H.A.; Carnahan, C.L.; Javandel, I.; Tsang, C.F.

1993-01-01

The geohydrologic data collected at Rainier Mesa provide the only extensive observations in tunnels presently available on flow and transport in tuff units similar to those of a potential nuclear waste repository at Yucca Mountain. This information can, therefore, be of great value in planning the Exploratory Studies Facility (ESF) testing in underground drifts at Yucca Mountain. In this paper, we compare the geohydrologic characteristics of tuff units of these two sites and summarize the hydrochemical data indicating the presence of nearly meteoric water in Rainier Mesa tunnels. A simple analytic model is used to evaluate the possibility of propagating transient pulses of water along fractures or faults through the Paintbrush nonwelded tuff unit to reach the tunnel beds below. The results suggest that fast flow could occur without significant mixing between meteoric fracture water and matrix pore water. The implications of these findings on planning for the ESF Calico Hills study at Yucca Mountain are discussed

Fault detection and isolation in systems with parametric faults

DEFF Research Database (Denmark)

Stoustrup, Jakob; Niemann, Hans Henrik

1999-01-01

The problem of fault detection and isolation of parametric faults is considered in this paper. A fault detection problem based on parametric faults are associated with internal parameter variations in the dynamical system. A fault detection and isolation method for parametric faults is formulated...

Geomorphic evidence for enhanced Pliocene-Quaternary faulting in the northwestern Basin and Range

Science.gov (United States)

Ellis, Magdalena A; Barnes Jason B,; Colgan, Joseph P.

2014-01-01

Mountains in the U.S. Basin and Range Province are similar in form, yet they have different histories of deformation and uplift. Unfortunately, chronicling fault slip with techniques like thermochronology and geodetics can still leave sizable, yet potentially important gaps at Pliocene–Quaternary (∼105–106 yr) time scales. Here, we combine existing geochronology with new geomorphic observations and approaches to investigate the Miocene to Quaternary slip history of active normal faults that are exhuming three footwall ranges in northwestern Nevada: the Pine Forest Range, the Jackson Mountains, and the Santa Rosa Range. We use the National Elevation Dataset (10 m) digital elevation model (DEM) to measure bedrock river profiles and hillslope gradients from these ranges. We observe a prominent suite of channel convexities (knickpoints) that segment the channels into upper reaches with low steepness (mean ksn = ∼182; θref = 0.51) and lower, fault-proximal reaches with high steepness (mean ksn = ∼361), with a concomitant increase in hillslope angles of ∼6°–9°. Geologic maps and field-based proxies for rock strength allow us to rule out static causes for the knickpoints and interpret them as transient features triggered by a drop in base level that created ∼20% of the existing relief (∼220 m of ∼1050 m total). We then constrain the timing of base-level change using paleochannel profile reconstructions, catchment-scale volumetric erosion fluxes, and a stream-power–based knickpoint celerity (migration) model. Low-temperature thermochronology data show that faulting began at ca. 11–12 Ma, yet our results estimate knickpoint initiation began in the last 5 Ma and possibly as recently as 0.1 Ma with reasonable migration rates of 0.5–2 mm/yr. We interpret the collective results to be evidence for enhanced Pliocene–Quaternary fault slip that may be related to tectonic reorganization in the American West, although we cannot rule out climate as a

Hamiltonian flow over saddles for exploring molecular phase space structures

Science.gov (United States)

Farantos, Stavros C.

2018-03-01

Despite using potential energy surfaces, multivariable functions on molecular configuration space, to comprehend chemical dynamics for decades, the real happenings in molecules occur in phase space, in which the states of a classical dynamical system are completely determined by the coordinates and their conjugate momenta. Theoretical and numerical results are presented, employing alanine dipeptide as a model system, to support the view that geometrical structures in phase space dictate the dynamics of molecules, the fingerprints of which are traced by following the Hamiltonian flow above saddles. By properly selecting initial conditions in alanine dipeptide, we have found internally free rotor trajectories the existence of which can only be justified in a phase space perspective. This article is part of the theme issue `Modern theoretical chemistry'.

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

International Nuclear Information System (INIS)

Cumbest, R.J.

2000-01-01

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

Corrigendum to Preconditioners for regularized saddle point problems with an application for heterogeneous Darcy flow problems

Czech Academy of Sciences Publication Activity Database

Axelsson, Owe; Blaheta, Radim

2016-01-01

Roč. 298, May 2016 (2016), s. 252-255 ISSN 0377-0427 R&D Projects: GA MŠk ED1.1.00/02.0070 Institutional support: RVO:68145535 Keywords : saddle point systems * conditions of nonsingularity * spectrum of preconditioned systems Subject RIV: BA - General Mathematics Impact factor: 1.357, year: 2016 http://www.sciencedirect.com/science/article/pii/S0377042715005889

Ash-flow tuff distribution and fault patterns as indicators of rotation of late-tertiary regional extension, Nevada test site

International Nuclear Information System (INIS)

Ander, H.D.

1983-01-01

Isopach and structure contour maps generated for Yucca Flat as well as fault pattern analyses of the Nevada Test Site (NTS) can aid in more efficient site selection and site characterization necessary for containment. Furthermore, these geologic studies indicate that most of the alluvial deposition in Yucca Flat was controlled by north-trending faults responding to a regional extension direction oriented approximately 20 0 to 30 0 west of the N50 0 W direction observed today. The Yucca Flat basin-forming Carpetbag and Yucca fault systems seem to be deflected at their southern ends into the northeast-trending Cane Spring and Mine Mountain fault systems. Left-lateral strike-slip displacement of approx. 1.4 km found on these northeasterly faults requires that most of the displacement on the combined fault systems occurred in an extension field oriented approximately N80 0 W. Fault movement in this extensional field postdates the Ammonia Tanks tuff (approx. 11 My) and was strongly active during deposition of some 1100 meters of alluvium in Yucca Flat. Time of rotation of regional extension to the presently active N50 0 W direction is unknown; however, it occurred so recently that it has not greatly modified fault displacement patterns extant at the NTS

Automatic identification of fault zone head waves and direct P waves and its application in the Parkfield section of the San Andreas Fault, California

Science.gov (United States)

Li, Zefeng; Peng, Zhigang

2016-06-01

Fault zone head waves (FZHWs) are observed along major strike-slip faults and can provide high-resolution imaging of fault interface properties at seismogenic depth. In this paper, we present a new method to automatically detect FZHWs and pick direct P waves secondary arrivals (DWSAs). The algorithm identifies FZHWs by computing the amplitude ratios between the potential FZHWs and DSWAs. The polarities, polarizations and characteristic periods of FZHWs and DSWAs are then used to refine the picks or evaluate the pick quality. We apply the method to the Parkfield section of the San Andreas Fault where FZHWs have been identified before by manual picks. We compare results from automatically and manually picked arrivals and find general agreement between them. The obtained velocity contrast at Parkfield is generally 5-10 per cent near Middle Mountain while it decreases below 5 per cent near Gold Hill. We also find many FZHWs recorded by the stations within 1 km of the background seismicity (i.e. the Southwest Fracture Zone) that have not been reported before. These FZHWs could be generated within a relatively wide low velocity zone sandwiched between the fast Salinian block on the southwest side and the slow Franciscan Mélange on the northeast side. Station FROB on the southwest (fast) side also recorded a small portion of weak precursory signals before sharp P waves. However, the polarities of weak signals are consistent with the right-lateral strike-slip mechanisms, suggesting that they are unlikely genuine FZHW signals.

Electrical design of the BUSSARD inverter system for ASDEX upgrade saddle coils

Energy Technology Data Exchange (ETDEWEB)

Teschke, Markus, E-mail: teschke@ipp.mpg.de; Arden, Nils; Eixenberger, Horst; Rott, Michael; Suttrop, Wolfgang

2015-10-15

Highlights: • A cost effective inverter topology for AUG's 16 in-vessel saddle coils has been found. • Use of commercially available power modules is possible. • A NPC-like topology of the power stage is realized in a modular way. • The high-speed controllers and PWM engines are realized on Linux-based systems. • First experimental results of AUG plasma shots are presented. - Abstract: A set of 16 in-vessel saddle coils is installed in the ASDEX Upgrade (AUG) nuclear fusion experiment for mitigation of edge localized modes (ELM) and feedback control of resistive wall modes (RWM). The coils were driven by DC current only during previous campaigns. Now, a new inverter system “BUSSARD” (German abbr. for “Bayerischer Umrichter, schnell schaltend für AUGs rasche Drehfelder”, translated: “bavarian fast switching inverter for AUG's fast rotating fields”) is built for the experiment. A four-phase system has been assembled to simultaneously operate up to 4 groups of coils consisting of up to 4 serial-connected coils each. The maximum current is 1.3 kA with a ripple in the range of 7% and the frequency is variable between DC and approx. 100 Hz. The switching frequency is variable between approximately 3 and 10 kHz. As a first application, rotating fields are generated. The system can be enhanced in two stages to 16-phase operation with a bandwidth of 500 Hz and a 24 phase system with a bandwidth of up to 3 kHz.

A synthesis of mineralization styles and geodynamic settings of the Paleozoic and Mesozoic metallic ore deposits in the Altay Mountains, NW China

Science.gov (United States)

Yang, Fuquan; Geng, Xinxia; Wang, Rui; Zhang, Zhixin; Guo, Xuji

2018-06-01

The Altay Mountains within the Xinjiang region of northwestern China hosts major metallic ore deposits. Here we review the geological characteristics, metallogenic features and tectonic settings of these deposits. The metallic ore deposits in the Altay Mountains occur mainly within four regions: North Altay, Central Altay, South Altay and Erqis. We recognize seven types of metallic ore deposits in the Altay Mountains: VMS, submarine volcanogenic iron, magmatic, skarn, pegmatite, hydrothermal vein (Cu-Zn, Fe) and orogenic gold. Among these types, the VMS, pegmatite, orogenic gold and skarn deposits are the most common. Most of the rare metal pegmatite deposits are distributed in Central Altay, with only a few in South Altay. The VMS, submarine volcanogenic type iron and skarn-type deposits are distributed in South Altay, whereas the orogenic-type gold deposits are distributed in the Erqis Fault belt. The hydrothermal vein-type deposits occur in the Erqis Fault belt and Chonghu'er Basin in South Altay. Magmatic-type deposits are mostly in the Erqis Fault belt and Central Altay. Based on isotopic age data, the VMS, submarine volcanogenic-type Fe and skarn-type Cu, Pb, Zn, Fe mineralization occurred during Early-Middle Devonian (∼410-377 Ma), orogenic-type Au, magmatic-type Cu-Ni, and a small number of skarn-type Fe, hydrothermal vein-type Cu-Zn, pegmatite-type rare-metal deposits in Early-Middle Permian (293-261 Ma), pegmatite-type rare-metal deposits, few skarn-type Fe deposit in Early-Middle Triassic (248-232 Ma), and dominantly represented by pegmatite-type rare-metal deposits in Late Triassic-Early Jurassic (223-180 Ma). The metallic ore deposits in the Altay Mountains formed in various tectonic settings, such as the Early-Middle Devonian continental arc and oceanic island arc, Early-Middle Permian post-collisional extensional setting, and Triassic-Early Jurassic intracontinental setting.

Active tectonics of the Rif Mountains (Morocco) from geomorphic and geochronological data

Science.gov (United States)

Ritz, Jean-François; Poujol, Antoine; Tahayt, Abdelilah; Vernant, Philippe; Condomines, Michel; Blard, Pierre-Henri; Braucher, Régis; Benedetti, Lucilla; Bourles, Didier; Leroux-Mallouf, Romain; Ferry, Matthieu; Maate, Soufian

2014-05-01

We present results of a geomorphological and morphotectonic analysis of the Rif Mountains (Morocco). We show that the present day kinematics of the Rif is characterized by active deformation along normal and left-lateral strike-slip faults in the North-East (Trougout, Rouadi, Boujibar and Nekor faults), reverse fault in the South (the South Rif Front) and inherited fold structures in the West. Digital Elevation Models of offset drainage features (streams, fluvial terraces) allow determining horizontal cumulative displacements of ~25-35m along the Trougout fault and ~40m along the Nekor fault. 14C dating of tectonic markers yields vertical and horizontal slip rates of ~2.8 mm/yr and ~2.3 mm/yr respectively, along the Trougout fault. For the first time, cosmogenic 3He method is used on volcanic rocks to date the successive exposure of the fault plane. Along the Trougout fault, this yields recurrence time between 3,1 and 4,1 ka. The present-day localized transtension seen in the northeastern Rif morphology (Ras Tarf) is coeval with uplifted marine terraces near the Al Hoceima Bay. U/Th dating of shells yields an average uplift rate of ~0.2 mm/yr during the past 500 Ka. These data show that active transtension in the northeastern Rif is also associated with uplift. Comparison with cosmogenic 10Be/3He dating of perched fluvial surface located above these marine terraces is in progress and may allow us to confirm or not this uplift rate. In the western Rif, geomorphic markers allow us to suggest that active deformation is accommodated along blind thrust and NNW-SSE inherited folds. These new morphotectonic constraints are consistent with the GPS measurements showing southwestward overall motion of most of the Rif belt with respect to stable Africa and suggest a continuum of the deformation from the Pliocene.

Faulting and groundwater in a desert environment: constraining hydrogeology using time-domain electromagnetic data

Science.gov (United States)

Bedrosian, Paul A.; Burgess, Matthew K.; Nishikawa, Tracy

2013-01-01

Within the south-western Mojave Desert, the Joshua Basin Water District is considering applying imported water into infiltration ponds in the Joshua Tree groundwater sub-basin in an attempt to artificially recharge the underlying aquifer. Scarce subsurface hydrogeological data are available near the proposed recharge site; therefore, time-domain electromagnetic (TDEM) data were collected and analysed to characterize the subsurface. TDEM soundings were acquired to estimate the depth to water on either side of the Pinto Mountain Fault, a major east-west trending strike-slip fault that transects the proposed recharge site. While TDEM is a standard technique for groundwater investigations, special care must be taken when acquiring and interpreting TDEM data in a twodimensional (2D) faulted environment. A subset of the TDEM data consistent with a layered-earth interpretation was identified through a combination of three-dimensional (3D) forward modelling and diffusion time-distance estimates. Inverse modelling indicates an offset in water table elevation of nearly 40 m across the fault. These findings imply that the fault acts as a low-permeability barrier to groundwater flow in the vicinity of the proposed recharge site. Existing production wells on the south side of the fault, together with a thick unsaturated zone and permeable near-surface deposits, suggest the southern half of the study area is suitable for artificial recharge. These results illustrate the effectiveness of targeted TDEM in support of hydrological studies in a heavily faulted desert environment where data are scarce and the cost of obtaining these data by conventional drilling techniques is prohibitive.

Corrective Action Investigation Plan for Corrective Action Unit 99: Rainier Mesa/Shoshone Mountain, Nevada Test Site, Nevada

International Nuclear Information System (INIS)

McCord, John

2004-01-01

caldera as well as from more distant sources. This has resulted in a layered volcanic stratigraphy composed of thick deposits of welded and nonwelded ash-flow tuff and lava flows. These deposits are proximal to the source caldera and are interstratified with the more distal facies of fallout tephra and bedded reworked tuff from more distant sources. In each area, a similar volcanic sequence was deposited upon Paleozoic carbonate and siliciclastic rocks that are disrupted by various thrust faults, normal faults, and strike-slip faults. In both Rainier Mesa (km) to the southwest, and Tippipah Spring, 4 km to the north, and the tunnel complex is dry. Particle-tracking simulations performed during the value of information analysis (VOIA) (SNJV, 2004b) indicate that most of the regional groundwater that underlies the test locations at Rainier Mesa and Shoshone Mountain eventually follows similar and parallel paths and ultimately discharges in Death Valley and the Amargosa Desert. Particle-tracking simulations conducted for the regional groundwater flow and risk assessment indicated that contamination from Rainier Mesa and Shoshone Mountain were unlikely to leave the NTS during the 1,000-year period of interest (DOE/NV, 1997a). It is anticipated that CAU-scale modeling will modify these results somewhat, but it is not expected to radically alter the outcome of these previous particle-tracking simulations within the 1,000-year period of interest. The Rainier Mesa/Shoshone Mountain CAIP describes the corrective action investigation (CAI) to be conducted at the Rainier Mesa/Shoshone Mountain CAU to evaluate the extent of contamination in groundwater due to the underground nuclear testing. The CAI will be conducted by the UGTA Project, which is part of the NNSA/NSO Environmental Restoration Project (ERP). The purpose and scope of the CAI are presented in this section, followed by a summary of the entire document

Magnetic paleointensities recorded in fault pseudotachylytes and implications for earthquake lightnings

Science.gov (United States)

Leibovitz, Natalie; Ferré, Eric; Geissman, John; Gattacceca, Jérôme

2015-04-01

Fault pseudotachylytes commonly form by frictional melting due to seismic slip. These fine-grained clastic rocks result from melt quenching and may show a high concentration of fine ferromagnetic grains. These grains are potentially excellent recorders of the rock natural remanent magnetization (NRM). The magnetization processes of fault pseudotachylytes are complex and may include the following: i) near coseismic thermal remanent magnetization (TRM) acquired upon cooling of the melt; ii) coseismic lightning induced remanent magnetization (LIRM) caused by earthquake lightnings (EQL); iii) post seismic chemical remanent magnetization (CRM) related to both devitrification and alteration. Deciphering these magnetization components is crucial to the interpretation of microstructures and the timing of microstructural development. Hence the paleomagnetic record of fault pseudotachylytes provides an independent set of new constraints on coseismic and post-seismic deformation. Fault pseudotachylytes from the Santa Rosa Mountains, California host a magnetic assemblage dominated by stoichiometric magnetite, formed from the breakdown of ferromagnesian silicates and melt oxidation at high temperature. Magnetite grain size in these pseudotachylytes compares to that of magnetites formed in friction experiments. Paleomagnetic data on these 59 Ma-old fault rocks reveal not only anomalous magnetization directions, inconsistent with the coseismic geomagnetic field, but also anomalously high magnetization intensities. Here we discuss preliminary results of paleointensity experiments designed to quantify the intensity of coseismic magnetizing fields. The REM' paleointensity method is particularly well suited to investigate NRMs resulting from non-conventional and multiple magnetization processes. The anomalously high NRM recorded in a few, but not all, specimens points to LIRM as the dominant origin of magnetization.

Improving Understanding of Spatial Heterogeneity in Mountain Ecohydrology with Multispectral Unmanned Aerial Systems (UAS).

Science.gov (United States)

Wigmore, O.; Molotch, N. P.

2017-12-01

Mountain regions are a critical component of the hydrologic system. These regions are extremely heterogeneous, with dramatic topographic, climatic, ecologic and hydrologic variations occurring over very short distances. This heterogeneity makes understanding changes in these environments difficult. Commonly used satellite data are often too coarse to resolve processes at appropriate scales and point measurements are typically unrepresentative of the wider region. The rapid rise of Unmanned Aerial Systems (UAS) offers a potential solution to the scale-related inadequacies of satellite and ground-based observing systems. Using UAS, spatially distributed datasets can be collected at high resolution (i.e. cm), on demand, and can therefore facilitate improved understanding of mountain ecohydrology. We deployed a custom built multispectral - visible (RGB), near infrared (NIR) and thermal infrared (TIR) - UAS at a weekly interval over the Niwot Ridge Long Term Ecological Research (NWT LTER) saddle catchment at 3500masl in the Colorado Rockies. This system was used to map surface water pathways, land cover and topography, and quantify ecohydrologic variables including, snow depth, vegetation productivity and surface soil moisture at 5-50cm resolution across an 80ha study area. This presentation will discuss the techniques, methods and merits of using UAS derived multispectral data for ecohydrologic research in mountain regions. We will also present preliminary findings from our survey time series at NWT LTER and a discussion of the potential insights that these datasets can provide. Key questions to be addressed are: 1) how does spatial variability in snow depth impact soil moisture and vegetation productivity, 2) how can UAS help us to identify ecohydrologic `hotspots' and `hot moments' across heterogeneous landscapes.

A description of a wide beam saddle field ion source used for nuclear target applications

International Nuclear Information System (INIS)

Greene, J.P.; Schiel, S.L.; Thomas, G.E.

1997-01-01

A description is given of a new, wide beam saddle field sputter source used for the preparation of targets applied in nuclear physics experiments. The ion source characteristics are presented and compared with published results obtained with other sources. Deposition rates acquired utilizing this source are given for a variety of target materials encountered in nuclear target production. New applications involving target thinning and ion milling are discussed

Unraveling the dynamics of magmatic CO2 degassing at Mammoth Mountain, California

Science.gov (United States)

Pfeiffer, Loic; Wanner, Christoph; Lewicki, Jennifer L.

2018-01-01

The accumulation of magmatic CO2 beneath low-permeability barriers may lead to the formation of CO2-rich gas reservoirs within volcanic systems. Such accumulation is often evidenced by high surface CO2 emissions that fluctuate over time. The temporal variability in surface degassing is believed in part to reflect a complex interplay between deep magmatic degassing and the permeability of degassing pathways. A better understanding of the dynamics of CO2 degassing is required to improve monitoring and hazards mitigation in these systems. Owing to the availability of long-term records of CO2 emissions rates and seismicity, Mammoth Mountain in California constitutes an ideal site towards such predictive understanding. Mammoth Mountain is characterized by intense soil CO2 degassing (up to ∼1000 t d−1) and tree kill areas that resulted from leakage of CO2 from a CO2-rich gas reservoir located in the upper ∼4 km. The release of CO2-rich fluids from deeper basaltic intrusions towards the reservoir induces seismicity and potentially reactivates faults connecting the reservoir to the surface. While this conceptual model is well-accepted, there is still a debate whether temporally variable surface CO2 fluxes directly reflect degassing of intrusions or variations in fault permeability. Here, we report the first large-scale numerical model of fluid and heat transport for Mammoth Mountain. We discuss processes (i) leading to the initial formation of the CO2-rich gas reservoir prior to the occurrence of high surface CO2 degassing rates and (ii) controlling current CO2 degassing at the surface. Although the modeling settings are site-specific, the key mechanisms discussed in this study are likely at play at other volcanic systems hosting CO2-rich gas reservoirs. In particular, our model results illustrate the role of convection in stripping a CO2-rich gas phase from a rising hydrothermal fluid and leading to an accumulation of a large mass of CO2 (∼107–108�

Unraveling the dynamics of magmatic CO2 degassing at Mammoth Mountain, California

Science.gov (United States)

Peiffer, Loïc; Wanner, Christoph; Lewicki, Jennifer L.

2018-02-01

The accumulation of magmatic CO2 beneath low-permeability barriers may lead to the formation of CO2-rich gas reservoirs within volcanic systems. Such accumulation is often evidenced by high surface CO2 emissions that fluctuate over time. The temporal variability in surface degassing is believed in part to reflect a complex interplay between deep magmatic degassing and the permeability of degassing pathways. A better understanding of the dynamics of CO2 degassing is required to improve monitoring and hazards mitigation in these systems. Owing to the availability of long-term records of CO2 emissions rates and seismicity, Mammoth Mountain in California constitutes an ideal site towards such predictive understanding. Mammoth Mountain is characterized by intense soil CO2 degassing (up to ∼1000 t d-1) and tree kill areas that resulted from leakage of CO2 from a CO2-rich gas reservoir located in the upper ∼4 km. The release of CO2-rich fluids from deeper basaltic intrusions towards the reservoir induces seismicity and potentially reactivates faults connecting the reservoir to the surface. While this conceptual model is well-accepted, there is still a debate whether temporally variable surface CO2 fluxes directly reflect degassing of intrusions or variations in fault permeability. Here, we report the first large-scale numerical model of fluid and heat transport for Mammoth Mountain. We discuss processes (i) leading to the initial formation of the CO2-rich gas reservoir prior to the occurrence of high surface CO2 degassing rates and (ii) controlling current CO2 degassing at the surface. Although the modeling settings are site-specific, the key mechanisms discussed in this study are likely at play at other volcanic systems hosting CO2-rich gas reservoirs. In particular, our model results illustrate the role of convection in stripping a CO2-rich gas phase from a rising hydrothermal fluid and leading to an accumulation of a large mass of CO2 (∼107-108 t) in a shallow

From fault classification to fault tolerance for multi-agent systems

CERN Document Server

Potiron, Katia; Taillibert, Patrick

2013-01-01

Faults are a concern for Multi-Agent Systems (MAS) designers, especially if the MAS are built for industrial or military use because there must be some guarantee of dependability. Some fault classification exists for classical systems, and is used to define faults. When dependability is at stake, such fault classification may be used from the beginning of the system's conception to define fault classes and specify which types of faults are expected. Thus, one may want to use fault classification for MAS; however, From Fault Classification to Fault Tolerance for Multi-Agent Systems argues that

Summary: beyond fault trees to fault graphs

International Nuclear Information System (INIS)

Alesso, H.P.; Prassinos, P.; Smith, C.F.

1984-09-01

Fault Graphs are the natural evolutionary step over a traditional fault-tree model. A Fault Graph is a failure-oriented directed graph with logic connectives that allows cycles. We intentionally construct the Fault Graph to trace the piping and instrumentation drawing (P and ID) of the system, but with logical AND and OR conditions added. Then we evaluate the Fault Graph with computer codes based on graph-theoretic methods. Fault Graph computer codes are based on graph concepts, such as path set (a set of nodes traveled on a path from one node to another) and reachability (the complete set of all possible paths between any two nodes). These codes are used to find the cut-sets (any minimal set of component failures that will fail the system) and to evaluate the system reliability

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

Science.gov (United States)

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

2010-01-01

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.

Late Quaternary offset of alluvial fan surfaces along the Central Sierra Madre Fault, southern California

Science.gov (United States)

Burgette, Reed J.; Hanson, Austin; Scharer, Katherine M.; Midttun, Nikolas

2016-01-01

The Sierra Madre Fault is a reverse fault system along the southern flank of the San Gabriel Mountains near Los Angeles, California. This study focuses on the Central Sierra Madre Fault (CSMF) in an effort to provide numeric dating on surfaces with ages previously estimated from soil development alone. We have refined previous geomorphic mapping conducted in the western portion of the CSMF near Pasadena, CA, with the aid of new lidar data. This progress report focuses on our geochronology strategy employed in collecting samples and interpreting data to determine a robust suite of terrace surface ages. Sample sites for terrestrial cosmogenic nuclide and luminescence dating techniques were selected to be redundant and to be validated through relative geomorphic relationships between inset terrace levels. Additional sample sites were selected to evaluate the post-abandonment histories of terrace surfaces. We will combine lidar-derived displacement data with surface ages to estimate slip rates for the CSMF.

The Role of Near-Fault Relief in Creating and Maintaining Strike-Slip Landscape Features

Science.gov (United States)

Harbert, S.; Duvall, A. R.; Tucker, G. E.

2016-12-01

Geomorphic landforms, such as shutter ridges, offset river terraces, and deflected stream channels, are often used to assess the activity and slip rates of strike-slip faults. However, in some systems, such as parts of the Marlborough Fault System (South Island, NZ), an active strike-slip fault does not leave a strong landscape signature. Here we explore the factors that dampen or enhance the landscape signature of strike-slip faulting using the Channel-Hillslope Integrated Landscape Development model (CHILD). We focus on variables affecting the length of channel offsets, which enhance the signature of strike-slip motion, and the frequency of stream captures, which eliminate offsets and reduce this signature. We model a strike-slip fault that passes through a mountain ridge, offsetting streams that drain across this fault. We use this setup to test the response of channel offset length and capture frequency to fault characteristics, such as slip rate and ratio of lateral to vertical motion, and to landscape characteristics, such as relief contrasts controlled by erodibility. Our experiments show that relief downhill of the fault, whether generated by differential uplift across the fault or by an erodibility contrast, has the strongest effect on offset length and capture frequency. This relief creates shutter ridges, which block and divert streams while being advected along a fault. Shutter ridges and the streams they divert have long been recognized as markers of strike-slip motion. Our results show specifically that the height of shutter ridges is most responsible for the degree to which they create long channel offsets by preventing stream captures. We compare these results to landscape metrics in the Marlborough Fault System, where shutter ridges are common and often lithologically controlled. We compare shutter ridge length and height to channel offset length in order to assess the influence of relief on offset channel features in a real landscape. Based on our

Bedrock geologic map of the central block area, Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

Day, W.C.; Potter, C.J.; Sweetkind, D.S.; Dickerson, R.P.; San Juan, C.A.

1998-01-01

Bedrock geologic maps form the foundation for investigations that characterize and assess the viability of the potential high-level radioactive waste repository at Yucca Mountain, Nevada. This study was funded by the US Department of Energy Yucca Mountain Project to provide a detailed (1:6,000-scale) bedrock geologic map for the area within and adjacent to the potential repository area at Yucca Mountain, Nye County, Nevada. Prior to this study, the 1:12,000-scale map of Scott and Bon, (1984) was the primary source of bedrock geologic data for the Yucca Mountain Project. However, targeted detailed mapping within the central block at Yucca Mountain revealed structural complexities along some of the intrablock faults that were not evident at 1:12,000 (Scott and Bonk, 1984). As a result, this study was undertaken to define the character and extent of the dominant structural features in the vicinity of the potential repository. In addition to structural considerations, ongoing subsurface excavation and geologic mapping within the exploratory Studies Facility (ESF), development of a three-dimensional-framework geologic model, and borehole investigations required use of a constituent stratigraphic system to facilitate surface to underground comparisons. The map units depicted in this report correspond as closely as possible to the proposed stratigraphic nomenclature by Buesch and others (1996), as described here

Approximate Dual Averaging Method for Multiagent Saddle-Point Problems with Stochastic Subgradients

Directory of Open Access Journals (Sweden)

Deming Yuan

2014-01-01

Full Text Available This paper considers the problem of solving the saddle-point problem over a network, which consists of multiple interacting agents. The global objective function of the problem is a combination of local convex-concave functions, each of which is only available to one agent. Our main focus is on the case where the projection steps are calculated approximately and the subgradients are corrupted by some stochastic noises. We propose an approximate version of the standard dual averaging method and show that the standard convergence rate is preserved, provided that the projection errors decrease at some appropriate rate and the noises are zero-mean and have bounded variance.

Fault tolerant control for uncertain systems with parametric faults

DEFF Research Database (Denmark)

Niemann, Hans Henrik; Poulsen, Niels Kjølstad

2006-01-01

A fault tolerant control (FTC) architecture based on active fault diagnosis (AFD) and the YJBK (Youla, Jarb, Bongiorno and Kucera)parameterization is applied in this paper. Based on the FTC architecture, fault tolerant control of uncertain systems with slowly varying parametric faults...... is investigated. Conditions are given for closed-loop stability in case of false alarms or missing fault detection/isolation....

Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria

Directory of Open Access Journals (Sweden)

Briestenský Miloš

2015-10-01

Full Text Available The EU-TecNet monitoring network uses customized three-dimensional extensometers to record transient deformations across individual faults. This paper presents the first results from two newly established monitoring points in the Balkan Mountains in Bulgaria. The data from Saeva Dupka, recorded across an EEN-WWS striking fault, show sinistral strike-slip along the fault and subsidence of the southern block. Much of the subsidence occurred around the time of the distal MW = 5.6 Pernik Earthquake. An important transient deformation event, which began in autumn 2012, was reflected by significant compression and following extension, across the monitored fault. The data from Bacho Kiro, recorded across a NE–SW striking fault, show sinistral strike-slip along the fault and subsidence of the north-western block. The same important deformation event was reflected by changes in the strike-slip, dip-slip, and horizontal opening/closing trends. These results have been compared to data from other monitoring points in the Western Carpathians, External Dinarides, and Tian Shan. Many of the sites show evidence of simultaneous displacement anomalies and this observation is interpreted as a reflection of the plate-wide propagation of a tectonic pressure pulse towards the end of 2012.

Flash Flood Type Identification within Catchments in Beijing Mountainous Area

Science.gov (United States)

Nan, W.

2017-12-01

Flash flood is a common type of disaster in mountainous area, Flash flood with the feature of large flow rate, strong flushing force, destructive power, has periodically caused loss to life and destruction to infrastructure in mountainous area. Beijing as China's political, economic and cultural center, the disaster prevention and control work in Beijing mountainous area has always been concerned widely. According to the transport mechanism, sediment concentration and density, the flash flood type identification within catchment can provide basis for making the hazards prevention and mitigation policy. Taking Beijing as the study area, this paper extracted parameters related to catchment morphological and topography features respectively. By using Bayes discriminant, Logistic regression and Random forest, the catchments in Beijing mountainous area were divided into water floods process, fluvial sediment transport process and debris flows process. The results found that Logistic regression analysis showed the highest accuracy, with the overall accuracy of 88.2%. Bayes discriminant and Random forest had poor prediction effects. This study confirmed the ability of morphological and topography features to identify flash flood process. The circularity ratio, elongation ratio and roughness index can be used to explain the flash flood types effectively, and the Melton ratio and elevation relief ratio also did a good job during the identification, whereas the drainage density seemed not to be an issue at this level of detail. Based on the analysis of spatial patterns of flash flood types, fluvial sediment transport process and debris flow process were the dominant hazards, while the pure water flood process was much less. The catchments dominated by fluvial sediment transport process were mainly distributed in the Yan Mountain region, where the fault belts were relatively dense. The debris flow process prone to occur in the Taihang Mountain region thanks to the abundant

LAMPF first-fault identifier for fast transient faults

International Nuclear Information System (INIS)

Swanson, A.R.; Hill, R.E.

1979-01-01

The LAMPF accelerator is presently producing 800-MeV proton beams at 0.5 mA average current. Machine protection for such a high-intensity accelerator requires a fast shutdown mechanism, which can turn off the beam within a few microseconds of the occurrence of a machine fault. The resulting beam unloading transients cause the rf systems to exceed control loop tolerances and consequently generate multiple fault indications for identification by the control computer. The problem is to isolate the primary fault or cause of beam shutdown while disregarding as many as 50 secondary fault indications that occur as a result of beam shutdown. The LAMPF First-Fault Identifier (FFI) for fast transient faults is operational and has proven capable of first-fault identification. The FFI design utilized features of the Fast Protection System that were previously implemented for beam chopping and rf power conservation. No software changes were required

Why the 2002 Denali fault rupture propagated onto the Totschunda fault: implications for fault branching and seismic hazards

Science.gov (United States)

Schwartz, David P.; Haeussler, Peter J.; Seitz, Gordon G.; Dawson, Timothy E.

2012-01-01

The propagation of the rupture of the Mw7.9 Denali fault earthquake from the central Denali fault onto the Totschunda fault has provided a basis for dynamic models of fault branching in which the angle of the regional or local prestress relative to the orientation of the main fault and branch plays a principal role in determining which fault branch is taken. GeoEarthScope LiDAR and paleoseismic data allow us to map the structure of the Denali-Totschunda fault intersection and evaluate controls of fault branching from a geological perspective. LiDAR data reveal the Denali-Totschunda fault intersection is structurally simple with the two faults directly connected. At the branch point, 227.2 km east of the 2002 epicenter, the 2002 rupture diverges southeast to become the Totschunda fault. We use paleoseismic data to propose that differences in the accumulated strain on each fault segment, which express differences in the elapsed time since the most recent event, was one important control of the branching direction. We suggest that data on event history, slip rate, paleo offsets, fault geometry and structure, and connectivity, especially on high slip rate-short recurrence interval faults, can be used to assess the likelihood of branching and its direction. Analysis of the Denali-Totschunda fault intersection has implications for evaluating the potential for a rupture to propagate across other types of fault intersections and for characterizing sources of future large earthquakes.

Strontium isotope geochemistry of soil and playa a deposits near Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Marshall, B.D.; Mahan, S.A.

1994-01-01

The isotopic composition of strontium contained in the carbonate fractions of soils provides an excellent tracer which can be used to test models for their origin. This paper reports data on surface coatings and cements, eolian sediments, playas and alluvial fan soils which help to constrain a model for formation of the extensive calcretes and fault infilling in the Yucca Mountain region. The playas contain carbonate with a wide range of strontium compositions; further work will be required to fully understand their possible contributions to the pedogenic carbonate system. Soils from an alluvial fan to the west of Yucca Mountain show that only small amounts of strontium are derived from weathering of silicate detritus. However, calcretes from a fan draining a carbonate terrane have strontium compositions dominated locally by the limestone strontium component. Although much evidence points to an eolian source for at least some of the strontium in the pedogenic carbonates near Yucca Mountain, an additional component or past variation of strontium composition in the eolian source is required to model the pedogenic carbonate system

Modeling flow and transport pathways to the potential repository horizon at Yucca Mountain

International Nuclear Information System (INIS)

Wolfsberg, A.V.; Roemer, G.J.C.; Fabryka-Martin, J.T.; Robinson, B.A.

1998-01-01

The isotopic ratios of 36 Cl/Cl are used in conjunction with geologic interpretation and numerical modeling to evaluate flow and transport pathways, processes, and model parameters in the unsaturated zone at Yucca Mountain. By synthesizing geochemical and geologic data, the numerical model results provide insight into the validity of alternative hydrologic parameter sets, flow and transport processes in and away from fault zones, and the applicability of 36 Cl/Cl ratios for evaluating alternative conceptual models

US Geological Survey Committee for the Advancement of Science in the Yucca Mountain Project symposium on open-quotes Fractures, Hydrology, and Yucca Mountainclose quotes: Abstracts and summary

International Nuclear Information System (INIS)

Gomberg, J.

1991-01-01

The principal objective of this symposium is to review the available information on fractured/faulted terrains in terms of a coherent hydrogeologic model of ground-water fluid flow and transport, particularly as it pertains to the Yucca Mountain region. This review addresses the influence and significance of fractures on ground-water flow and the transport of conservative-species solutes within the context of the hydrogeologic setting of the Yucca Mountain area. The relations between fluid flow and fractured or faulted host rock are examined integrally from information on geologic, seismologic, hydrologic, and geomechanical properties of the system. The development of new hydrogeologic approaches that incorporate information from this integrated database are contrasted with more standard approaches toward understanding flow in fractured reservoirs. Ground-water flow in both the unsaturated zone and the saturated zone are considered. The application of various models of flow is addressed, examples include porous-media equivalent and discontinuum fracture-network models. Data and interpretations from the Yucca Mountain area are presented to establish a context for information exchange. The symposium includes discussions relevant to technical considerations for characterizing the Yucca Mountain area hydrogeology. On the basis of these discussions, CASY has compiled this document in order to formally summarize the proceedings and communicate recommendations for future directions of research and investigation

Crestal unconformities on an exposed Jurassic tilted fault block, Wollaston Forland, East Greenland as an analogue for buried hydrocarbon traps

DEFF Research Database (Denmark)

Surlyk, Finn; Korstgård, J.

2013-01-01

The stratigraphy of successions exposed in footwall crests of tilted fault blocks is commonly highly complex. Crestal stratigraphy and structure are particularly difficult to unravel in the subsurface due to poor seismic resolution across fault zones, footwall collapse, and coalescing syn- and post......-rift unconformities. Crestal ridges are important elements in basin evolution, as they form drainage divides and sediment sources for aprons along footwall scarps and hangingwall deltas. A Middle Jurassic – lowermost Cretaceous footwall crest is exceptionally well exposed in the mountain Stratumbjerg in Wollaston...... Forland, East Greenland. Rifting and block tilting was initiated in the (?)Bajocian, intensified in the Oxfordian–Kimmeridgian, culminated in latest Jurassic, Volgian, time and faded out in the earliest Cretaceous. The main border faults of the westward tilted blocks trend roughly N–S. The first early syn...

The Mountains of Io: Global and Geological Perspectives from Voyager and Galileo

Science.gov (United States)

Schenk, Paul; Hargitai, Henrik; Wilson, Ronda; McEwen, Alfred; Thomas, Peter; Bredekamp, Joe (Technical Monitor)

2001-01-01

the lower crust induced by global subsidence might be reduced, encouraging volcanism and discouraging mountain building. In regions of mantle downwelling, these compressive stresses in the lower crust might be increased, discouraging volcanism and encouraging mountain building. Alternatively, the global pattern may be related to possible (but undocumented) nonsynchronous rotation of lo, which would produce two regions each of compression and extension in the crust. Evidence of layering and of mass wasting, including landslides, block sliding, debris aprons and downslope creep, on Ionian mountains suggests that the crust of Io is essentially a layered stack of partially consolidated volcanic lavas and plume deposits, becoming more consolidated with depth. The lower crust especially may also be ductily deformed, punctuated by volcanic intrusions and faulting at paterae, and broken into blocks, some of which have been uplifted to form mountains.

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

Science.gov (United States)

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

2014-11-01

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.

Fault tree handbook

International Nuclear Information System (INIS)

Haasl, D.F.; Roberts, N.H.; Vesely, W.E.; Goldberg, F.F.

1981-01-01

This handbook describes a methodology for reliability analysis of complex systems such as those which comprise the engineered safety features of nuclear power generating stations. After an initial overview of the available system analysis approaches, the handbook focuses on a description of the deductive method known as fault tree analysis. The following aspects of fault tree analysis are covered: basic concepts for fault tree analysis; basic elements of a fault tree; fault tree construction; probability, statistics, and Boolean algebra for the fault tree analyst; qualitative and quantitative fault tree evaluation techniques; and computer codes for fault tree evaluation. Also discussed are several example problems illustrating the basic concepts of fault tree construction and evaluation

Fault isolability conditions for linear systems with additive faults

DEFF Research Database (Denmark)

Niemann, Hans Henrik; Stoustrup, Jakob

2006-01-01

In this paper, we shall show that an unlimited number of additive single faults can be isolated under mild conditions if a general isolation scheme is applied. Multiple faults are also covered. The approach is algebraic and is based on a set representation of faults, where all faults within a set...

Integrating GIS-based geologic mapping, LiDAR-based lineament analysis and site specific rock slope data to delineate a zone of existing and potential rock slope instability located along the grandfather mountain window-Linville Falls shear zone contact, Southern Appalachian Mountains, Watauga County, North Carolina

Science.gov (United States)

Gillon, K.A.; Wooten, R.M.; Latham, R.L.; Witt, A.W.; Douglas, T.J.; Bauer, J.B.; Fuemmeler, S.J.

2009-01-01

Landslide hazard maps of Watauga County identify >2200 landslides, model debris flow susceptibility, and evaluate a 14km x 0.5km zone of existing and potential rock slope instability (ZEPRSI) near the Town of Boone. The ZEPRSI encompasses west-northwest trending (WNWT) topographic ridges where 14 active/past-active rock/weathered rock slides occur mainly in rocks of the Grandfather Mountain Window (GMW). The north side of this ridgeline is the GMW / Linville Falls Fault (LFF) contact. Sheared rocks of the Linville Falls Shear Zone (LFSZ) occur along the ridge and locally in the valley north of the contact. The valley is underlain principally by layered granitic gneiss comprising the Linville Falls/Beech Mountain/Stone Mountain Thrust Sheet. The integration of ArcGIS??? - format digital geologic and lineament mapping on a 6m LiDAR (Light Detecting and Ranging) digital elevation model (DEM) base, and kinematic analyses of site specific rock slope data (e.g., presence and degree of ductile and brittle deformation fabrics, rock type, rock weathering state) indicate: WNWT lineaments are expressions of a regionally extensive zone of fractures and faults; and ZEPRSI rock slope failures concentrate along excavated, north-facing LFF/LFSZ slopes where brittle fabrics overprint older metamorphic foliations, and other fractures create side and back release surfaces. Copyright 2009 ARMA, American Rock Mechanics Association.

Fault diagnosis and fault-tolerant control based on adaptive control approach

CERN Document Server

Shen, Qikun; Shi, Peng

2017-01-01

This book provides recent theoretical developments in and practical applications of fault diagnosis and fault tolerant control for complex dynamical systems, including uncertain systems, linear and nonlinear systems. Combining adaptive control technique with other control methodologies, it investigates the problems of fault diagnosis and fault tolerant control for uncertain dynamic systems with or without time delay. As such, the book provides readers a solid understanding of fault diagnosis and fault tolerant control based on adaptive control technology. Given its depth and breadth, it is well suited for undergraduate and graduate courses on linear system theory, nonlinear system theory, fault diagnosis and fault tolerant control techniques. Further, it can be used as a reference source for academic research on fault diagnosis and fault tolerant control, and for postgraduates in the field of control theory and engineering. .

Seismicity in the Vicinity of Yucca Mountain, Nevada, for the Period October 1, 2004 to September 30, 2006

International Nuclear Information System (INIS)

Smith, Ken

2007-01-01

This report describes earthquake activity within approximately 65 km of Yucca Mountain site during the October 1, 2004 to September 30, 2006 time period (FY05-06). The FY05-06 earthquake activity will be compared with the historical and more recent period of seismic activity in the Yucca Mountain region. The relationship between the distribution of seismicity and active faults, historical patterns of activity, and rates of earthquakes (number of events and their magnitudes) are important components in the assessment of the seismic hazard for the Yucca Mountain site. Since October 1992 the University of Nevada has compiled a catalog of earthquakes in the Yucca Mountain area. Seismicity reports have identified notable earthquake activity, provided interpretations of the seismotectonics of the region, and documented changes in the character of earthquake activity based on nearly 30 years of site-characterization monitoring. Data from stations in the seismic network in the vicinity of Yucca Mountain is collected and managed at the Nevada Seismological Laboratory (NSL) at the University of Nevada Reno (UNR). Earthquake events are systematically identified and cataloged under Implementing Procedures developed in compliance with the Nevada System of Higher Education (NSHE) Quality Assurance Program. The earthquake catalog for FY05-06 in the Yucca Mountain region submitted to the Yucca Mountain Technical Data Management System (TDMS) forms the basis of this report

A summary of the active fault investigation in the extension sea area of Kikugawa fault and the Nishiyama fault , N-S direction fault in south west Japan

Science.gov (United States)

Abe, S.

2010-12-01

In this study, we carried out two sets of active fault investigation by the request from Ministry of Education, Culture, Sports, Science and Technology in the sea area of the extension of Kikugawa fault and the Nishiyama fault. We want to clarify the five following matters about both active faults based on those results. (1)Fault continuity of the land and the sea. (2) The length of the active fault. (3) The division of the segment. (4) Activity characteristics. In this investigation, we carried out a digital single channel seismic reflection survey in the whole area of both active faults. In addition, a high-resolution multichannel seismic reflection survey was carried out to recognize the detailed structure of a shallow stratum. Furthermore, the sampling with the vibrocoring to get information of the sedimentation age was carried out. The reflection profile of both active faults was extremely clear. The characteristics of the lateral fault such as flower structure, the dispersion of the active fault were recognized. In addition, from analysis of the age of the stratum, it was recognized that the thickness of the sediment was extremely thin in Holocene epoch on the continental shelf in this sea area. It was confirmed that the Kikugawa fault extended to the offing than the existing results of research by a result of this investigation. In addition, the width of the active fault seems to become wide toward the offing while dispersing. At present, we think that we can divide Kikugawa fault into some segments based on the distribution form of the segment. About the Nishiyama fault, reflection profiles to show the existence of the active fault was acquired in the sea between Ooshima and Kyushu. From this result and topographical existing results of research in Ooshima, it is thought that Nishiyama fault and the Ooshima offing active fault are a series of structure. As for Ooshima offing active fault, the upheaval side changes, and a direction changes too. Therefore, we

Fault finder

Science.gov (United States)

Bunch, Richard H.

1986-01-01

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.

Miocene Tectonics at the Pannonian - Carpathian Transition: The Bogdan Voda - Dragos Voda fault system, northern Romania

Science.gov (United States)

Tischler, M.; Gröger, H.; Marin, M.; Schmid, S. M.; Fügenschuh, B.

2003-04-01

Tertiary tectonics in the Pannonian-Carpathian transition zone was dominated by opposed rotations of Alcapa and Tisza-Dacia, separated by the Mid-Hungarian lineament (MHL). While in the Pannonian basin the MHL is well known from geophysical and borehole data, its northeastern continuation remains a matter of discussion. Our field based study, located in the Maramures mountains of northern Romania, provides new kinematic data from the Bogdan Voda fault, a first order candidate for the prolongation of the MHL to the northeast. In the Burdigalian, the Pienides (unmetamorphic flysch nappes) were emplaced onto the autochthonous Paleogene flysch units. Kinematic data consistently indicate top to the SE-directed thrusting of the Pienides and selected imbrications in the autochthonous units. Between Langhian and Tortonian these thrust contacts were offset by the E-W trending Bogdan Voda fault and its eastern continuation, the Dragos-Voda fault. These two faults share a common polyphase history, at least since the Burdigalian. Kinematic data derived from mesoscale faults indicate sinistral strike-slip displacement, in good agreement with kinematics inferred from map view. The NE-SW trending Greben fault, another fault of regional importance, was coevally active as a normal fault. From stratigraphic arguments major activity of this fault system is constrained to the time interval between 16.4-10 Ma. While deformation is strongly concentrated in the sedimentary units, the easterly located basement units are affected by abundant minor faults of similar kinematics covering a wide area. These SW-NE trending strike slip faults feature a normal component and resemble an imbricate fan geometry. Since Burdigalian thrusting is consistently SE-directed on either side of the Bogdan-Dragos Voda fault, major post-Burdigalian differential rotations can be excluded for the northern and southern block respectively. Hydrothermal veins within Pannonian volcanic units are aligned along the

The Sorong Fault Zone, Indonesia: Mapping a Fault Zone Offshore

Science.gov (United States)

Melia, S.; Hall, R.

2017-12-01

The Sorong Fault Zone is a left-lateral strike-slip fault zone in eastern Indonesia, extending westwards from the Bird's Head peninsula of West Papua towards Sulawesi. It is the result of interactions between the Pacific, Caroline, Philippine Sea, and Australian Plates and much of it is offshore. Previous research on the fault zone has been limited by the low resolution of available data offshore, leading to debates over the extent, location, and timing of movements, and the tectonic evolution of eastern Indonesia. Different studies have shown it north of the Sula Islands, truncated south of Halmahera, continuing to Sulawesi, or splaying into a horsetail fan of smaller faults. Recently acquired high resolution multibeam bathymetry of the seafloor (with a resolution of 15-25 meters), and 2D seismic lines, provide the opportunity to trace the fault offshore. The position of different strands can be identified. On land, SRTM topography shows that in the northern Bird's Head the fault zone is characterised by closely spaced E-W trending faults. NW of the Bird's Head offshore there is a fold and thrust belt which terminates some strands. To the west of the Bird's Head offshore the fault zone diverges into multiple strands trending ENE-WSW. Regions of Riedel shearing are evident west of the Bird's Head, indicating sinistral strike-slip motion. Further west, the ENE-WSW trending faults turn to an E-W trend and there are at least three fault zones situated immediately south of Halmahera, north of the Sula Islands, and between the islands of Sanana and Mangole where the fault system terminates in horsetail strands. South of the Sula islands some former normal faults at the continent-ocean boundary with the North Banda Sea are being reactivated as strike-slip faults. The fault zone does not currently reach Sulawesi. The new fault map differs from previous interpretations concerning the location, age and significance of different parts of the Sorong Fault Zone. Kinematic

Three-Dimensional Analysis of dike/fault interaction at Mono Basin (California) using the Finite Element Method

Science.gov (United States)

La Marra, D.; Battaglia, M.

2013-12-01

Mono Basin is a north-trending graben that extends from the northern edge of Long Valley caldera towards the Bodie Hills and is bounded by the Cowtrack Mountains on the east and the Sierra Nevada on the west. The Mono-Inyo Craters volcanic chain forms a north-trending zone of volcanic vents extending from the west moat of the Long Valley caldera to Mono Lake. The Hartley Springs fault transects the southern Mono Craters-Inyo Domes area between the western part of the Long Valley caldera and June Lake. Stratigraphic data suggest that a series of strong earthquakes occurred during the North Mono-Inyo eruption sequence of ~1350 A.D. The spatial and temporal proximity between Hartley Springs Fault motion and the North Mono-Inyo eruption sequence suggests a possible relation between seismic events and eruptions. We investigate the interactions between slip along the Hartley Springs fault and dike intrusion beneath the Mono-Inyo craters using a three-dimensional finite element model of the Mono Basin. We employ a realistic representation of the Basin that includes topography, vertical and lateral heterogeneities of the crust, contact relations between fault planes, and a physical model of the pressure required to propagate the dike. We estimate (a) the distribution of Coulomb stress changes to study the influence of dike intrusion on Hartley Springs fault, and (b) the local stress and volumetric dilatation changes to understand how fault slip may influence the propagation of a dike towards the surface.

Topography, stresses, and stability at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Swolfs, H.S.; Savage, W.Z.

1985-01-01

Plane-strain solutions are used to analyze the influence of topography on the state of stress at Yucca Mountain, Nye County, Nevada. The results are in good agreement with the measured stress components obtained in drill holes by the hydraulic-fracturing technique, particularly those measured directly beneath the crest of the ridge, and indicate that these stresses are gravitationally induced. A separate analysis takes advantage of the fact that a well-developed set of vertical faults and fractures, subparallel to the ridge trend, imparts a vertical transverse isotropy to the rock and that, as a consequence of gravitational loading, unequal horizontal stresses are induced in directions perpendicular and parallel to the anisotropy

Wind turbine fault detection and fault tolerant control

DEFF Research Database (Denmark)

Odgaard, Peter Fogh; Johnson, Kathryn

2013-01-01

In this updated edition of a previous wind turbine fault detection and fault tolerant control challenge, we present a more sophisticated wind turbine model and updated fault scenarios to enhance the realism of the challenge and therefore the value of the solutions. This paper describes...

On the many saddle points description of quantum black holes

Energy Technology Data Exchange (ETDEWEB)

Germani, Cristiano, E-mail: cristiano.germani@physik.uni-muenchen.de

2014-06-02

Considering two dimensional gravity coupled to a CFT, we show that a semiclassical black hole can be described in terms of two Liouville theories matched at the horizon. The black hole exterior corresponds to a space-like while the interior to a time-like Liouville theory. This matching automatically implies that a semiclassical black hole has an infinite entropy. The path integral description of the time-like Liouville theory (the Black Hole interior) is studied and it is found that the correlation functions of the coupled CFT-gravity system are dominated by two (complex) saddle points, even in the semiclassical limit. We argue that this system can be interpreted as two interacting Bose–Einstein condensates constructed out of two degenerate quantum states. In AdS/CFT context, the same system is mapped into two interacting strings intersecting inside a three-dimensional BTZ black hole.

Late Cenozoic transpressional mountain building directly north of the Altyn Tagh Fault in the Sanweishan and Nanjieshan, North Tibetan Foreland, China

Science.gov (United States)

Cunningham, Dickson; Zhang, Jin; Li, Yanfeng

2016-09-01

For many tectonicists, the structural development of the northern Tibetan Plateau stops at the Altyn Tagh Fault (ATF). This study challenges that assumption. Structural field observations and remote sensing analysis indicate that the Sanweishan and Nanjieshan basement cored ridges of the Archean Dunhuang Block, which interrupt the north Tibetan foreland directly north of the ATF, are bound and cut by an array of strike-slip, thrust and oblique-slip faults that have been active in the Quaternary and remain potentially active. The Sanweishan is a SE-tilted block that is bound on its NW margin by a steep south-dipping thrust fault that has also accommodated sinistral strike-slip displacements. The Nanjieshan consists of parallel, but offset basement ridges that record NNW and SSE thrust displacements and sinistral strike-slip. Regional folds characterize the extreme eastern Nanjieshan and appear to have formed above blind thrust faults which break the surface further west. Previously published magnetotelluric data suggest that the major faults of the Sanweishan and Nanjieshan ultimately root to the south within conductive zones that are inferred to merge into the ATF. Therefore, although the southern margin of the Dunhuang Block focuses significant deformation along the ATF, the adjacent cratonic basement to the north is also affected. Collectively, the ATF and structurally linked Sanweishan and Nanjieshan fault array represent a regional asymmetric half-flower structure that is dominated by non-strain partitioned sinistral transpression. The NW-trending Dengdengshan thrust fault system near Yumen City appears to define the northeastern limit of the Sanweishan-Nanjieshan block, which may be regionally viewed as the most northern, but early-stage expression of Tibetan Plateau growth into a slowly deforming, mechanically stiff Archean craton.

New Geologic Data on the Seismic Risks of the Most Dangerous Fault on Shore in Central Japan, the Itoigawa-Shizuoka Tectonic Line Active Fault System

Science.gov (United States)

Okumura, K.; Kondo, H.; Toda, S.; Takada, K.; Kinoshita, H.

2006-12-01

Ten years have past since the first official assessment of the long-term seismic risks of the Itoigawa-Shizuoka tectonic line active fault system (ISTL) in 1996. The disaster caused by the1995 Kobe (Hyogo-ken-Nanbu) earthquake urged the Japanese government to initiated a national project to assess the long-term seismic risks of on-shore active faults using geologic information. ISTL was the first target of the 98 significant faults and the probability of a M7 to M8 event turned out to be the highest among them. After the 10 years of continued efforts to understand the ISTL, now it is getting ready to revise the assessment. Fault mapping and segmentation: The most active segment of the Gofukuji fault (~1 cm/yr left-lateral strike slip, R=500~800 yrs.) had been maped only for less than 10 km. Adjacent segments were much less active. This large slip on such a short segment was contradictory. However, detailed topographic study including Lidar survey revealed the length of the Gofukuji fault to be 25 km or more. High slip rate with frequent earthquakes may be restricted to the Gofukuji fault while the 1996 assessment modeled frequent >100 km rupture scenario. The geometry of the fault is controversial especially on the left-lateral strike-slip section of the ISTL. There are two models of high-angle Middel ISTL and low-angle Middle ISTL with slip partitioning. However, all geomorphic and shallow geologic data supports high-angle almost pure strike slip on the faults in the Middle ISTL. CRIEPI's 3- dimensional trenching in several sites as well as the previous results clearly demonstrated repeated pure strike-slip offset during past a few events. In Middle ISTL, there is no evidence of recent activity of pre-existing low-angle thrust faults that are inferred to be active from shallow seismic survey. Separation of high (~3000 m) mountain ranges and low (lack of reliable time constraints on past earthquakes. In order to solve this problem, we have carried out intensive

Tritium, carbon-14, and iodine-129 as indicators for localized vertical recharge along an anticline in the Columbia River Basalts using a decay-corrected mixing model

Energy Technology Data Exchange (ETDEWEB)

Hall, S.H.; Johnson, V.G.; Early, T.O.

1987-11-01

Tritium, /sup 14/C, and /sup 129/I in groundwater samples are used to demonstrate vertical recharge and measure flow velocity in the fractured and faulted Umtanum Ridge-Gable Mountain acticline, within the Columbia River Basalts, at a sampling site about 6 mi northeast of the proposed high-level nuclear waste repository at the Hanford Site, Washington State. Mixing model calculations yield an apparent downward migration rate of 15 to 19 ft/yr through a sequence of aquifers in the Wanapum Basalt that range in depth from 698 to 1373 ft. Estimates of the vertical flow rate in the overlying Saddle Mountains Basalt are somewhat higher. Hydrographs from neighboring wells, hydrostatic heads, pump test data, and the chemical composition of groundwater samples from the sampling well are consistent with interaquifer communication. Some hydrologic evidence from aquifers in this region suggests that, in the past, flow may have been upward. This possible reversal of flow may be associated with water table mounding in the unconfined aquifer, caused by waste disposal activities at the Hanford Site since World War II. 17 refs., 12 figs., 3 tabs.

Fault-weighted quantification method of fault detection coverage through fault mode and effect analysis in digital I&C systems

Energy Technology Data Exchange (ETDEWEB)

Cho, Jaehyun; Lee, Seung Jun, E-mail: sjlee420@unist.ac.kr; Jung, Wondea

2017-05-15

Highlights: • We developed the fault-weighted quantification method of fault detection coverage. • The method has been applied to specific digital reactor protection system. • The unavailability of the module had 20-times difference with the traditional method. • Several experimental tests will be effectively prioritized using this method. - Abstract: The one of the most outstanding features of a digital I&C system is the use of a fault-tolerant technique. With an awareness regarding the importance of thequantification of fault detection coverage of fault-tolerant techniques, several researches related to the fault injection method were developed and employed to quantify a fault detection coverage. In the fault injection method, each injected fault has a different importance because the frequency of realization of every injected fault is different. However, there have been no previous studies addressing the importance and weighting factor of each injected fault. In this work, a new method for allocating the weighting to each injected fault using the failure mode and effect analysis data was proposed. For application, the fault-weighted quantification method has also been applied to specific digital reactor protection system to quantify the fault detection coverage. One of the major findings in an application was that we may estimate the unavailability of the specific module in digital I&C systems about 20-times smaller than real value when we use a traditional method. The other finding was that we can also classify the importance of the experimental case. Therefore, this method is expected to not only suggest an accurate quantification procedure of fault-detection coverage by weighting the injected faults, but to also contribute to an effective fault injection experiment by sorting the importance of the failure categories.

Fault diagnosis

Science.gov (United States)

Abbott, Kathy

1990-01-01

The objective of the research in this area of fault management is to develop and implement a decision aiding concept for diagnosing faults, especially faults which are difficult for pilots to identify, and to develop methods for presenting the diagnosis information to the flight crew in a timely and comprehensible manner. The requirements for the diagnosis concept were identified by interviewing pilots, analyzing actual incident and accident cases, and examining psychology literature on how humans perform diagnosis. The diagnosis decision aiding concept developed based on those requirements takes abnormal sensor readings as input, as identified by a fault monitor. Based on these abnormal sensor readings, the diagnosis concept identifies the cause or source of the fault and all components affected by the fault. This concept was implemented for diagnosis of aircraft propulsion and hydraulic subsystems in a computer program called Draphys (Diagnostic Reasoning About Physical Systems). Draphys is unique in two important ways. First, it uses models of both functional and physical relationships in the subsystems. Using both models enables the diagnostic reasoning to identify the fault propagation as the faulted system continues to operate, and to diagnose physical damage. Draphys also reasons about behavior of the faulted system over time, to eliminate possibilities as more information becomes available, and to update the system status as more components are affected by the fault. The crew interface research is examining display issues associated with presenting diagnosis information to the flight crew. One study examined issues for presenting system status information. One lesson learned from that study was that pilots found fault situations to be more complex if they involved multiple subsystems. Another was pilots could identify the faulted systems more quickly if the system status was presented in pictorial or text format. Another study is currently under way to

Slip rate of the Calico fault: Implications for geologic versus geodetic rate discrepancy in the Eastern California Shear Zone

Science.gov (United States)

Oskin, Michael; Perg, Lesley; Blumentritt, Dylan; Mukhopadhyay, Sujoy; Iriondo, Alexander

2007-03-01

Long-term (105 years) fault slip rates test the scale of discrepancy between infrequent paleoseismicity and relatively rapid geodetic rates of dextral shear in the Eastern California Shear Zone (ECSZ). The Calico fault is one of a family of dextral faults that traverse the Mojave Desert portion of the ECSZ. Its slip rate is determined from matching and dating incised Pleistocene alluvial fan deposits and surfaces displaced by fault slip. A high-resolution topographic base acquired via airborne laser swath mapping aids in identification and mapping of deformed geomorphic features. The oldest geomorphically preserved alluvial fan, unit B, is displaced 900 ± 200 m from its source at Sheep Springs Wash in the northern Rodman Mountains. This fan deposit contains the first preserved occurrence of basalt clasts derived from the Pipkin lava field and overlies Quaternary conglomerate deposits lacking these clasts. The 40Ar/39Ar dating of two flows from this field yields consistent ages of 770 ± 40 ka and 735 ± 9 ka. An age of 650 ± 100 ka is assigned to this fan deposit based on these ages and on the oldest cosmogenic 3He exposure date of 653 ± 20 ka on a basalt boulder from the surface of unit B. This assigned age and offset together yield a mid-Pleistocene to present average slip rate of 1.4 ± 0.4 mm/yr. A younger fan surface, unit K, records 100 ± 10 m of dextral displacement and preserves original depositional morphology of its surface. Granitic boulders and pavement samples from this surface yield an average age of 56.4 ± 7.7 ka after taking into account minimal cosmogenic inheritance of granitic clasts. The displaced and dated K fans yield a slip rate of 1.8 ± 0.3 mm/yr. Distributed deformation of the region surrounding the fault trace, if active, could increase the overall displacement rate to 2.1 ± 0.5 mm/yr. Acceleration of slip rate from an average of 1.4 mm/yr prior to ˜50 ka to 1.8 mm/yr since ˜50 ka is possible, though a single time-averaged slip

Cenozoic mountain building on the northeastern Tibetan Plateau

Science.gov (United States)

Lease, Richard O.

2014-01-01

Northeastern Tibetan Plateau growth illuminates the kinematics, geodynamics, and climatic consequences of large-scale orogenesis, yet only recently have data become available to outline the spatiotemporal pattern and rates of this growth. I review the tectonic history of range growth across the plateau margin north of the Kunlun fault (35°–40°N) and east of the Qaidam basin (98°–107°E), synthesizing records from fault-bounded mountain ranges and adjacent sedimentary basins. Deformation began in Eocene time shortly after India-Asia collision, but the northeastern orogen boundary has largely remained stationary since this time. Widespread middle Miocene–Holocene range growth is portrayed by accelerated deformation, uplift, erosion, and deposition across northeastern Tibet. The extent of deformation, however, only expanded ~150 km outward to the north and east and ~150 km laterally to the west. A middle Miocene reorganization of deformation characterized by shortening at various orientations heralds the onset of the modern kinematic regime where shortening is coupled to strike slip. This regime is responsible for the majority of Cenozoic crustal shortening and thickening and the development of the northeastern Tibetan Plateau.

Evaluation for characteristics of around the Nojima fault; Butsuri tansa ni yoru `Nojima jishin danso` shuhen no jiban bussei ni kansuru ichihyoka

Energy Technology Data Exchange (ETDEWEB)

Shimizu, K; Tsuji, T [Newjec Inc., Osaka (Japan); Tsuji, M [OYO Corp., Tokyo (Japan)

1996-05-01

Various surveys were conducted for the area around the Nojima fault, including ground surface, two-dimensional electrical and boring surveys and elastic wave tomography, in order to grasp properties of the ground around the `Nojima earthquake fault.` The resistivity image method as one of the two-dimensional electrical methods was used to grasp fault shapes over a wide range of the 1.6km long section extending between Esaki and Hirabayashi. The courses of traverse were set in the direction almost perpendicular to the fault. Boreholes were excavated and elastic wave tomography was conducted between the boreholes on the 9th and 17th courses of traverse, to confirm ground/mountain conditions and to compare the results with observed elastic wave velocities. Very low resistivities are observed at places where granite is distributed, suggesting that the fault-induced changes are not limited to the area around the fault. The zone in which elastic wave velocity decreases is narrow, 10m at the longest, at a velocity of 2.4km/s or lower, which is a low velocity for that propagating in granite. 5 refs., 4 figs.

Novel spin transition between S = 5/2 and S = 3/2 in highly saddled iron(III) porphyrin complexes at extremely low temperatures.

Science.gov (United States)

Ohgo, Yoshiki; Chiba, Yuya; Hashizume, Daisuke; Uekusa, Hidehiro; Ozeki, Tomoji; Nakamura, Mikio

2006-05-14

A novel spin transition between S = 5/2 and S = 3/2 has been observed for the first time in five-coordinate, highly saddled iron(III) porphyrinates by EPR and SQUID measurements at extremely low temperatures.

Coulomb stress transfer and tectonic loading preceding the 2002 Denali fault earthquake

Science.gov (United States)

Bufe, Charles G.

2006-01-01

fault uniformly away from thrust failure by about 100 kPa. The initiation of the Denali fault earthquake was advanced by transfer of 30–50 kPa of positive Coulomb stress to the Susitna Glacier fault (Anderson and Ji, 2003) by the nearby M 6.7 Nenana Mountain foreshock of 23 October 2002. The regional tectonic loading model used here suggests that the Semidi (Alaska Peninsula) segment of the megathrust that ruptured in 1938 (M 8.2) may be reloaded and approaching failure.

Fault zone hydrogeology

Science.gov (United States)

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

2013-12-01

Deformation along faults in the shallow crust (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.

Classical generalized transition-state theory. Application to a collinear reaction with two saddle points

International Nuclear Information System (INIS)

Garrett, B.C.; Truhlar, D.G.; Grev, R.S.

1981-01-01

Accurate classical dynamical fixed-energy reaction probabilities and fixed-temperature rate constants are calculated for the collinear reaction H + FH on a low-barrier model potential energy surface. The calculations cover energies from 0.1 to 100 kcal/mol above threshold and temperatures of 100 to 10,000 K. The accurate results are used to test five approximate theories: conventional transition-state theory (TST), canonical variational theory (CVT), improved canonical variational theory (ICVT), microcanonical variational theory (μVT), and the unified statistical model (US). The first four of these theories involve a single dividing surface in phase space, and the US theory involves three dividing surfaces. The tests are particularly interesting because the potential energy surface has two identical saddle points. At temperatures from 100 to 2000 K, the μVt is the most accurate theory, with errors in the range 11 to 14%; for temperatures from 2000 to 10,000 K, the US theory is the most successful, with errors in the range 3 to 14%. Over the whole range, a factor of 100 in temperature, both theories have errors of 35% or less. Even TST has errors of 47% or less over the whole factor-of-100 temperature range. Although the US model should become exact at threshold for this system, it already underestimates the reaction probability by a factor of 0.64 at 0.1 kcal/mol above threshold. TST and μVT agree with each other within 12% up to an energy 13 kcal/mol above the saddle point energy. 3 figures, 2 tables

Imaging of Subsurface Faults using Refraction Migration with Fault Flooding

KAUST Repository

Metwally, Ahmed Mohsen Hassan

2017-05-31

We propose a novel method for imaging shallow faults by migration of transmitted refraction arrivals. The assumption is that there is a significant velocity contrast across the fault boundary that is underlain by a refracting interface. This procedure, denoted as refraction migration with fault flooding, largely overcomes the difficulty in imaging shallow faults with seismic surveys. Numerical results successfully validate this method on three synthetic examples and two field-data sets. The first field-data set is next to the Gulf of Aqaba and the second example is from a seismic profile recorded in Arizona. The faults detected by refraction migration in the Gulf of Aqaba data were in agreement with those indicated in a P-velocity tomogram. However, a new fault is detected at the end of the migration image that is not clearly seen in the traveltime tomogram. This result is similar to that for the Arizona data where the refraction image showed faults consistent with those seen in the P-velocity tomogram, except it also detected an antithetic fault at the end of the line. This fault cannot be clearly seen in the traveltime tomogram due to the limited ray coverage.

Imaging of Subsurface Faults using Refraction Migration with Fault Flooding

KAUST Repository

Metwally, Ahmed Mohsen Hassan; Hanafy, Sherif; Guo, Bowen; Kosmicki, Maximillian Sunflower

2017-01-01

We propose a novel method for imaging shallow faults by migration of transmitted refraction arrivals. The assumption is that there is a significant velocity contrast across the fault boundary that is underlain by a refracting interface. This procedure, denoted as refraction migration with fault flooding, largely overcomes the difficulty in imaging shallow faults with seismic surveys. Numerical results successfully validate this method on three synthetic examples and two field-data sets. The first field-data set is next to the Gulf of Aqaba and the second example is from a seismic profile recorded in Arizona. The faults detected by refraction migration in the Gulf of Aqaba data were in agreement with those indicated in a P-velocity tomogram. However, a new fault is detected at the end of the migration image that is not clearly seen in the traveltime tomogram. This result is similar to that for the Arizona data where the refraction image showed faults consistent with those seen in the P-velocity tomogram, except it also detected an antithetic fault at the end of the line. This fault cannot be clearly seen in the traveltime tomogram due to the limited ray coverage.

Architecture of thrust faults with alongstrike variations in fault-plane dip: anatomy of the Lusatian Fault, Bohemian Massif

Czech Academy of Sciences Publication Activity Database

Coubal, Miroslav; Adamovič, Jiří; Málek, Jiří; Prouza, V.

2014-01-01

Roč. 59, č. 3 (2014), s. 183-208 ISSN 1802-6222 Institutional support: RVO:67985831 ; RVO:67985891 Keywords : fault architecture * fault plane geometry * drag structures * thrust fault * sandstone * Lusatian Fault Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.405, year: 2014

State of Nevada comments on the US Department of Energy site characterization plan, Yucca Mountain site, Nevada

International Nuclear Information System (INIS)

1989-09-01

The following document comprises a critical evaluation of the DOE's Site Characterization Plan (SCP). The comments address a number of issues related to the scientific methods involved in the proposed procedures of site characterization, the suitability and integration of the methods, and the validity of the approach taken by the DOE in the context of the NRC regulations. The SCP contains many improvements of the Draft Environmental Assessment (DEA) and the Environmental Assessment (EA), and fewer improvements of the SCP Consultation Draft. An obvious attempt has been made to address topics that were regarded in these previous reviews as deficiencies in the study program. For example, the activity and seismogenic potential of the Quaternary faults at Yucca Mountain are treated much more realistically than orignally proposed by the DOE, even though published data has not increased significantly since the DEA and EA were released. Water is now recognized as a resource, and faults and fault breccias are recognized as potential hosts for epithermal mineralization. There has, in addition, been considerable effort to incorporate a number of alternative conceptual models (involving both cross sections of Yucca Mountain and regional tectonic models) into the realm of tectonic hypotheses. There is a little doubt that the SCP proposes an exhaustive and wide-ranging scope of investigations for the purpose of site characterization, and that many of these investigations have been included by the DOE in response to critical reviews by external groups (such as the NRC and various State of Nevada agencies)

Rate of deformation in the Pasco Basin during the Miocene as determined by distribution of Columbia River basalt flows

International Nuclear Information System (INIS)

Reidel, S.P.; Ledgerwood, R.K.; Myers, C.W.; Jones, M.G.; Landon, R.D.

1980-03-01

Detailed mapping of over 8000 square kilometers and logs from 20 core holes were used to determine the distribution and thickness of basalt flows and interbeds in the Pasco Basin. The data indicate the high-MgO Grande Ronde Basalt and Wanapum Basalt thicken from the northeast to the southwest. Deformation began in late Frenchman Springs time in the Saddle Mountains along a northwest-southeast trend and in Roza time along an east-west trend. By late Wanapum time, basalt flows were more restricted on the east side. Saddle Mountains Basalt flows spread out in the basin from narrow channels to the east. The Umatilla Member entered from the southeast and is confined to the south-central basin, while the Wilbur Creek, Asotin, Esquatzel, Pomona, and Elephant Mountain Members entered from the east and northeast. The distribution of these members is controlled by flow volume, boundaries of other flows, and developing ridges. The Wilbur Creek, Asotin, and Esquatzel flows exited from the basin in a channel along the northern margin of the Umatilla flow, while the Pomona and Elephant Mountain flows exited between Umtanum Ridge and Wallula Gap. The thickness of sedimentary interbeds and basalt flows indicated subsidence and/or uplift began in post-Grande Ronde time (14.5 million years before present) and continued through Saddle Mountains time (10.5 million years before present). Maximum subsidence occurred 40 kilometers (24 miles) north of Richland, Washington with an approximate rate of 25 meters (81 feet) per million years during the eruption of the basalt. Maximum uplift along the developing ridges was 70 meters (230 feet) per million years

Fault-tolerant cooperative output regulation for multi-vehicle systems with sensor faults

Science.gov (United States)

Qin, Liguo; He, Xiao; Zhou, D. H.

2017-10-01

This paper presents a unified framework of fault diagnosis and fault-tolerant cooperative output regulation (FTCOR) for a linear discrete-time multi-vehicle system with sensor faults. The FTCOR control law is designed through three steps. A cooperative output regulation (COR) controller is designed based on the internal mode principle when there are no sensor faults. A sufficient condition on the existence of the COR controller is given based on the discrete-time algebraic Riccati equation (DARE). Then, a decentralised fault diagnosis scheme is designed to cope with sensor faults occurring in followers. A residual generator is developed to detect sensor faults of each follower, and a bank of fault-matching estimators are proposed to isolate and estimate sensor faults of each follower. Unlike the current distributed fault diagnosis for multi-vehicle systems, the presented decentralised fault diagnosis scheme in each vehicle reduces the communication and computation load by only using the information of the vehicle. By combing the sensor fault estimation and the COR control law, an FTCOR controller is proposed. Finally, the simulation results demonstrate the effectiveness of the FTCOR controller.

Robust Mpc for Actuator–Fault Tolerance Using Set–Based Passive Fault Detection and Active Fault Isolation

Directory of Open Access Journals (Sweden)

Xu Feng

2017-03-01

Full Text Available In this paper, a fault-tolerant control (FTC scheme is proposed for actuator faults, which is built upon tube-based model predictive control (MPC as well as set-based fault detection and isolation (FDI. In the class of MPC techniques, tubebased MPC can effectively deal with system constraints and uncertainties with relatively low computational complexity compared with other robust MPC techniques such as min-max MPC. Set-based FDI, generally considering the worst case of uncertainties, can robustly detect and isolate actuator faults. In the proposed FTC scheme, fault detection (FD is passive by using invariant sets, while fault isolation (FI is active by means of MPC and tubes. The active FI method proposed in this paper is implemented by making use of the constraint-handling ability of MPC to manipulate the bounds of inputs.

Determining on-fault magnitude distributions for a connected, multi-fault system

Science.gov (United States)

Geist, E. L.; Parsons, T.

2017-12-01

A new method is developed to determine on-fault magnitude distributions within a complex and connected multi-fault system. A binary integer programming (BIP) method is used to distribute earthquakes from a 10 kyr synthetic regional catalog, with a minimum magnitude threshold of 6.0 and Gutenberg-Richter (G-R) parameters (a- and b-values) estimated from historical data. Each earthquake in the synthetic catalog can occur on any fault and at any location. In the multi-fault system, earthquake ruptures are allowed to branch or jump from one fault to another. The objective is to minimize the slip-rate misfit relative to target slip rates for each of the faults in the system. Maximum and minimum slip-rate estimates around the target slip rate are used as explicit constraints. An implicit constraint is that an earthquake can only be located on a fault (or series of connected faults) if it is long enough to contain that earthquake. The method is demonstrated in the San Francisco Bay area, using UCERF3 faults and slip-rates. We also invoke the same assumptions regarding background seismicity, coupling, and fault connectivity as in UCERF3. Using the preferred regional G-R a-value, which may be suppressed by the 1906 earthquake, the BIP problem is deemed infeasible when faults are not connected. Using connected faults, however, a solution is found in which there is a surprising diversity of magnitude distributions among faults. In particular, the optimal magnitude distribution for earthquakes that participate along the Peninsula section of the San Andreas fault indicates a deficit of magnitudes in the M6.0- 7.0 range. For the Rodgers Creek-Hayward fault combination, there is a deficit in the M6.0- 6.6 range. Rather than solving this as an optimization problem, we can set the objective function to zero and solve this as a constraint problem. Among the solutions to the constraint problem is one that admits many more earthquakes in the deficit magnitude ranges for both faults

Compound nucleus decay: Comparison between saddle point and scission point barriers

Energy Technology Data Exchange (ETDEWEB)

Santos, T. J.; Carlson, B. V. [Depto. de Física, Instituto Tecnológico de Aeronáutica, São José dos Campos, SP (Brazil)

2014-11-11

One of the principal characteristics of nuclear multifragmentation is the emission of complex fragments of intermediate mass. An extension of the statistical multifragmentation model has been developed, in which the process can be interpreted as the near simultaneous limit of a series of sequential binary decays. In this extension, intermediate mass fragment emissions are described by expressions almost identical to those of light particle emission. At lower temperatures, similar expressions have been shown to furnish a good description of very light intermediate mass fragment emission but not of the emission of heavier fragments, which seems to be determined by the transition density at the saddle-point rather than at the scission point. Here, we wish to compare these different formulations of intermediate fragmment emission and analyze the extent to which they remain distinguishable at high excitation energy.

[The Waste Package Project. Final report, July 1, 1995--February 27, 1996]: Volume 3, Stress study in faulted tunnel models by combined photoelastic measurements and finite element analysis

International Nuclear Information System (INIS)

Ladkany, S.G.; Huang, Yuping.

1996-01-01

The aim of this part of the Nuclear Waste Package Project research at UNLV is to investigate the stresses in a model of a faulted mountain and the effect of the fault on the stability of drifts in a proposed High Level Nuclear Waste Repository. An investigation was performed to develop a proper technique for analyzing the stresses in and around three adjacent scaled tunnel models, along with the stress concentration factors resulting from the existence of a fault that penetrates two of the three tunnels, at an inclined angel of 44 degrees to the horizontal plane. The results and experience gained from this investigation will be used in a future project in which a full-size repository drift and a penetrating fault will be modeled and analyzed

Impacts of seismic activity on long-term repository performance at Yucca Mountain

International Nuclear Information System (INIS)

Gauthier, J.H.; Wilson, M.L.; Borns, D.J.; Arnold, B.W.

1995-01-01

Several effects of seismic activity on the release of radionuclides from a potential repository at Yucca Mountain are quantified. Future seismic events are predicted using data from the seismic hazard analysis conducted for the Exploratory Studies Facility (ESF). Phenomenological models are developed, including rockfall (thermal-mechanical and seismic) in unbackfilled emplacement drifts, container damage caused by fault displacement within the repository, and flow-path chance caused by changes in strain. Using the composite-porosity flow model (relatively large-scale, regular percolation), seismic events show little effect on total-system releases; using the weeps flow model (episodic pulses of flow in locally saturated fractures), container damage and flow-path changes cause over an order of magnitude increase in releases. In separate calculations using, more realistic representations of faulting, water-table rise caused by seismically induced changes in strain are seen to be higher than previously estimated by others, but not sufficient to reach a potential repository

Controlling Unknown Saddle Type Steady States of Dynamical Systems with Latency in the Feedback Loop

DEFF Research Database (Denmark)

Tamasevicius, Arunas; Bumeliene, Skaidra; Tamaseviciute, Elena

2009-01-01

We suggest an adaptive control technique for stabilizing saddle type unstable steady states of dynamical systems. The controller is composed of an unstable and a stable high-pass filters operating in parallel. The mathematical model is considered analytically and numerically. The conjoint...... controller is sufficiently robust to time latencies in the feedback loop. In addition, it is not sensitive to the damping parameters of the system and is relatively fast. Experiments have been performed using a simplified version of the electronic Young-Silva circuit imitating behavior of the Duffing...

Eruptive history of Mammoth Mountain and its mafic periphery, California

Science.gov (United States)

Hildreth, Wes; Fierstein, Judy

2016-07-13

This report and accompanying geologic map portray the eruptive history of Mammoth Mountain and a surrounding array of contemporaneous volcanic units that erupted in its near periphery. The moderately alkaline Mammoth eruptive suite, basaltic to rhyodacitic, represents a discrete new magmatic system, less than 250,000 years old, that followed decline of the subalkaline rhyolitic system active beneath adjacent Long Valley Caldera since 2.2 Ma (Hildreth, 2004). The scattered vent array of the Mammoth system, 10 by 20 km wide, is unrelated to the rangefront fault zone, and its broad nonlinear footprint ignores both Long Valley Caldera and the younger Mono-Inyo rangefront vent alignment.

Fault-Tolerant Approach for Modular Multilevel Converters under Submodule Faults

DEFF Research Database (Denmark)

Deng, Fujin; Tian, Yanjun; Zhu, Rongwu

2016-01-01

The modular multilevel converter (MMC) is attractive for medium- or high-power applications because of the advantages of its high modularity, availability, and high power quality. The fault-tolerant operation is one of the important issues for the MMC. This paper proposed a fault-tolerant approach...... for the MMC under submodule (SM) faults. The characteristic of the MMC with arms containing different number of healthy SMs under faults is analyzed. Based on the characteristic, the proposed approach can effectively keep the MMC operation as normal under SM faults. It can effectively improve the MMC...

Pore Effect on the Occurrence and Formation of Gas Hydrate in Permafrost of Qilian Mountain, Qinghai-Tibet Plateau, China

Science.gov (United States)

Gao, H.; Lu, H.; Lu, Z.

2014-12-01

Gas hydrates were found in the permafrost of Qilian Mountain, Qinghai- Tibet Plateau, China in 2008. It has been found that gas hydrates occur in Jurassic sedimentary rocks, and the hydrated gases are mainly thermogenic. Different from the gas hydrates existing in loose sands in Mallik, Mackenzie Delta, Canada and North Slope, Alaska, USA, the gas hydrates in Qilian Mountain occurred in hard rocks. For understanding the occurrence and formation mechanism of gas hydrate in hard rcok, extensive experimental investigations have been conducted to study the pore features and hydrate formation in the rocks recovered from the hydrate layers in Qilian Mountain. The structures of sedimentary rock were observed by high-resolution X-ray CT, and pore size distribution of a rock specimen was measured with the mercury-injection method. Methane hydrate was synthesized in water-saturated rocks, and the saturations of hydrate in sedimentary rocks of various types were estimated from the amount of gas released from certain volume of rock. X-ray CT observation revealed that fractures were developed in the rocks associated with faults, while those away from faults were generally with massive structure. The mercury-injection analysis of pore features found that the porosities of the hydrate-existing rocks were generally less than 3%, and the pore sizes were generally smaller than 100 nm. The synthesizing experiments found that the saturation of methane hydrate were generally lower than 6% of pore space in rocks, but up to 16% when fractures developed. The low hydrate saturation in Qilian sedimentary rocks has been found mainly due to the small pore size of rock. The low hydrate saturation in the rocks might be the reason for the failure of regional seismic and logging detections of gas hydrates in Qilian Mountain.

Preliminary study of lead isotopes in the carbonate-silica veins of Trench 14, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Zartman, R.E.; Kwak, L.M.

1993-01-01

The sub-vertical carbonate-silica veins filling the Bow Ridge Fault, where exposed in Trench 14 on the east side of Yucca Mountain, carry a lead isotopic signature that can be explained in terms of local sources. Two isotopically distinguishable--silicate and carbonate--fractions of lead are recognized within the vein system as well as in overlying surficial calcrete deposits. The acid-insoluble silicate fraction is contributed largely from the decomposing Miocene volcanic tuff, which forms the wall rock of the fault zone and is a ubiquitous component of the overlying soil. Lead contained in the silicate fraction approaches in isotopic composition that of the Miocene volcanic rocks of Yucca Mountain, but diverges from it in some samples by being more enriched in uranogenic isotopes. The carbonate fraction of lead in both vein and calcrete samples resides dominantly in the HCl- and CH 3 COOH-soluble calcite. HCl evidently also attacks and removes lead from silicate phases, but the milder CH 3 COOH dissolution procedure oftentimes identifies a significantly more radiogenic lead in the calcite. Wind-blown particulate matter brought to the area from Paleozoic and Late Proterozoic limestones in surrounding mountains may be the ultimate source of the calcite. Isotopically more uniform samples suggest that locally the basaltic ash and other volcanic rock have contributed most of the lead to both fractions of the vein system. An important finding of this study is that the data does not require the more exotic mechanisms or origins that have been proposed for the veins. Instead, the remarkably similar lead isotopic properties of the veins to those of the soil calcretes support their interpretation as a surficial, pedogenic phenomenon

Saddle-fin cell transistors with oxide etch rate control by using tilted ion implantation (TIS-fin) for sub-50-nm DRAMs

International Nuclear Information System (INIS)

Yoo, Min Soo; Choi, Kang Sik; Sun, Woo Kyung

2010-01-01

As DRAM cell pitch size decreases, the need for a high performance transistor is increasing. Though saddle-fin (S-fin) transistors have superior characteristics, S-fin transistors are well known to be more sensitive to process variation. To make uniform S-fin transistors, for the first time, we developed a new fin formation method using tilted ion implantation along the wordline direction after a recess gate etch. Due to the increased etch rate of the oxide film by ion implantation damage, fins are made at the bottom channel of the recess gate after wet etching. The resulting tilt implanted saddle-fin (TIS-fin) transistor has remarkably improved characteristics, such as ∼8% subthreshold swing (SS) and a 40% drain induced barrier lowering (DIBL) decrease. Especially, the TIS-fin with a neutral dopant has a reduced threshold voltage (Vth) variation within a wafer (<100 mV), which is comparable with that of a mass-produced sphere-shaped recessed channel array transistor (SRCAT).

Magnetic paleointensities in fault pseudotachylytes and implications for earthquake lightnings

Science.gov (United States)

Leibovitz, Natalie Ruth

Fault pseudotachylytes commonly form by frictional melting due to seismic slip. These fine-grained clastic rocks result from melt quenching and may show a high concentration of fine ferromagnetic grains. These grains are potentially excellent recorders of the rock natural remanent magnetization (NRM). The magnetization processes of fault pseudotachylytes are complex and may include the following: i) near coseismic thermal remanent magnetization (TRM) acquired upon cooling of the melt; ii) coseismic lightning induced remanent magnetization (LIRM) caused by earthquake lightnings (EQL); iii) post seismic chemical remanent magnetization (CRM) related to both devitrification and alteration. Deciphering these magnetization components is crucial to the interpretation of paleointensities to see if coseismic phenomena such as EQL's were recorded within these rocks. Hence the paleomagnetic record of fault pseudotachylytes provides an independent set of new constraints on coseismic events. Fault pseudotachylytes from the Santa Rosa Mountains, California host a magnetic assemblage dominated by stoichiometric magnetite, formed from the breakdown of ferromagnesian silicates and melt oxidation at high temperature. Magnetite grain size in these pseudotachylytes compares to that of magnetite formed in friction experiments. Paleomagnetic data on these 59 Ma-old fault rocks reveal not only anomalous magnetization directions, inconsistent with the coseismic geomagnetic field, but also anomalously high magnetization intensities. Here we discuss results of rock magnetism and paleointensity experiments designed to quantify the intensity of coseismic magnetizing fields. The REM' paleointensity method, previously tested on meteorites, is particularly well suited to investigate NRMs resulting from non-conventional and multiple magnetization processes. Overall findings indicate an isothermal remanent magnetization (IRM) in some, but not all, specimens taken from four different Santa Rosa

Rectifier Fault Diagnosis and Fault Tolerance of a Doubly Fed Brushless Starter Generator

Directory of Open Access Journals (Sweden)

Liwei Shi

2015-01-01

Full Text Available This paper presents a rectifier fault diagnosis method with wavelet packet analysis to improve the fault tolerant four-phase doubly fed brushless starter generator (DFBLSG system reliability. The system components and fault tolerant principle of the high reliable DFBLSG are given. And the common fault of the rectifier is analyzed. The process of wavelet packet transforms fault detection/identification algorithm is introduced in detail. The fault tolerant performance and output voltage experiments were done to gather the energy characteristics with a voltage sensor. The signal is analyzed with 5-layer wavelet packets, and the energy eigenvalue of each frequency band is obtained. Meanwhile, the energy-eigenvalue tolerance was introduced to improve the diagnostic accuracy. With the wavelet packet fault diagnosis, the fault tolerant four-phase DFBLSG can detect the usual open-circuit fault and operate in the fault tolerant mode if there is a fault. The results indicate that the fault analysis techniques in this paper are accurate and effective.

Potentiometric-surface map, 1993, Yucca Mountain and vicinity, Nevada

International Nuclear Information System (INIS)

Tucci, P.; Burkhardt, D.J.

1995-01-01

The revised potentiometric surface map here, using mainly 1993 average water levels, updates earlier maps of this area. Water levels are contoured with 20-m intervals, with additional 0.5-m contours in the small-gradient area SE of Yucca Mountain. Water levels range from 728 m above sea level SE of Yucca to 1,034 m above sea level north of Yucca. Potentiometric levels in the deeper parts of the volcanic rock aquifer range from 730 to 785 m above sea level. The potentiometric surface can be divided into 3 regions: A small gradient area E and SE of Yucca, a moderate-gradient area on the west side of Yucca, and a large-gradient area to the N-NE of Yucca. Water levels from wells at Yucca were examined for yearly trends (1986-93) using linear least-squares regression. Of the 22 wells, three had significant positive trends. The trend in well UE-25 WT-3 may be influenced by monitoring equipment problems. Tends in USW WT-7 and USW WTS-10 are similar; both are located near a fault west of Yucca; however another well near that fault exhibited no significant trend

Fault displacement along the Naruto-South fault, the Median Tectonic Line active fault system in the eastern part of Shikoku, southwestern Japan

OpenAIRE

高田, 圭太; 中田, 高; 後藤, 秀昭; 岡田, 篤正; 原口, 強; 松木, 宏彰

1998-01-01

The Naruto-South fault is situated of about 1000m south of the Naruto fault, the Median Tectonic Line active fault system in the eastern part of Shikoku. We investigated fault topography and subsurface geology of this fault by interpretation of large scale aerial photographs, collecting borehole data and Geo-Slicer survey. The results obtained are as follows; 1) The Naruto-South fault runs on the Yoshino River deltaic plain at least 2.5 km long with fault scarplet. the Naruto-South fault is o...

Kinematics of active deformation across the Western Kunlun mountain range (Xinjiang, China), and potential seismic hazards within the southern Tarim Basin

DEFF Research Database (Denmark)

Guilbaud, Christelle; Simoes, Martine; Barrier, Laurie

2017-01-01

remains seismic. To quantify the rate of active deformation and the potential for major earthquakes in this region, we combine a structural and quantitative morphological analysis of the Yecheng-Pishan fold, along the topographic mountain front in the epicentral area. Using a seismic profile, we derive......The Western Kunlun mountain range is a slowly converging intra-continental orogen where deformation rates are too low to be properly quantified from geodetic techniques. This region has recorded little seismicity, but the recent July 2015 (Mw 6.4) Pishan earthquake shows that this mountain range...... a structural cross-section in which we identify the fault that broke during the Pishan earthquake, an 8-12 km deep blind ramp beneath the Yecheng-Pishan fold. Combining satellite images and DEMs, we achieve a detailed morphological analysis of the Yecheng-Pishan fold, where we find nine levels of incised...

Robust Fault Diagnosis Design for Linear Multiagent Systems with Incipient Faults

Directory of Open Access Journals (Sweden)

Jingping Xia

2015-01-01

Full Text Available The design of a robust fault estimation observer is studied for linear multiagent systems subject to incipient faults. By considering the fact that incipient faults are in low-frequency domain, the fault estimation of such faults is proposed for discrete-time multiagent systems based on finite-frequency technique. Moreover, using the decomposition design, an equivalent conclusion is given. Simulation results of a numerical example are presented to demonstrate the effectiveness of the proposed techniques.

Alpine Fault, New Zealand, SRTM Shaded Relief and Colored Height

Science.gov (United States)

2005-01-01

The Alpine fault runs parallel to, and just inland of, much of the west coast of New Zealand's South Island. This view was created from the near-global digital elevation model produced by the Shuttle Radar Topography Mission (SRTM) and is almost 500 kilometers (just over 300 miles) wide. Northwest is toward the top. The fault is extremely distinct in the topographic pattern, nearly slicing this scene in half lengthwise. In a regional context, the Alpine fault is part of a system of faults that connects a west dipping subduction zone to the northeast with an east dipping subduction zone to the southwest, both of which occur along the juncture of the Indo-Australian and Pacific tectonic plates. Thus, the fault itself constitutes the major surface manifestation of the plate boundary here. Offsets of streams and ridges evident in the field, and in this view of SRTM data, indicate right-lateral fault motion. But convergence also occurs across the fault, and this causes the continued uplift of the Southern Alps, New Zealand's largest mountain range, along the southeast side of the fault. Two visualization methods were combined to produce this image: shading and color coding of topographic height. The shade image was derived by computing topographic slope in the northwest-southeast (image top to bottom) direction, so that northwest slopes appear bright and southeast slopes appear dark. Color coding is directly related to topographic height, with green at the lower elevations, rising through yellow and tan, to white at the highest elevations. Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on Feb. 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 3-D measurements of the Earth's surface. To collect the 3-D data

Are turtleback fault surfaces common structural elements of highly extended terranes?

Science.gov (United States)

Çemen, Ibrahim; Tekeli, Okan; Seyitoğlu, Gűrol; Isik, Veysel

2005-12-01

The Death Valley region of the U.S.A. contains three topographic surfaces resembling the carapace of a turtle. These three surfaces are well exposed along the Black Mountain front and are named the Badwater, Copper Canyon, and Mormon Point Turtlebacks. It is widely accepted that the turtlebacks are also detachment surfaces that separate brittlely deformed Cenozoic volcanic and sedimentary rocks of the hanging wall from the strongly mylonitic, ductilely deformed pre-Cenozoic rocks of the footwall. We have found a turtleback-like detachment surface along the southern margin of the Alasehir (Gediz) Graben in western Anatolia, Turkey. This surface qualifies as a turtleback fault surface because it (a) is overall convex-upward and (b) separates brittlely deformed hanging wall Cenozoic sedimentary rocks from the ductilely to brittlely deformed, strongly mylonitic pre-Cenozoic footwall rocks. The surface, named here Horzum Turtleback, contains striations that overprint mylonitic stretching lineations indicating top to the NE sense of shear. This suggests that the northeasterly directed Cenozoic extension in the region resulted in a ductile deformation at depth and as the crust isostatically adjusted to the removal of the rocks in the hanging wall of the detachment fault, the ductilely deformed mylonitic rocks of the footwall were brought to shallower depths where they were brittlely deformed. The turtleback surfaces have been considered unique to the Death Valley region, although detachment surfaces, rollover folds, and other extensional structures have been well observed in other extended terranes of the world. The presence of a turtleback fault surface in western Anatolia, Turkey, suggests that the turtleback faults may be common structural features of highly extended terranes.

Seismic investigation of the Kunlun Fault: Analysis of the INDEPTH IV 2-D active-source seismic dataset

Science.gov (United States)

Seelig, William George

The Tibetan Plateau has experienced significant crustal thickening and deformation since the continental subduction and collision of the Asian and Indian plates in the Eocene. Deformation of the northern Tibetan Plateau is largely accommodated by strike-slip faulting. The Kunlun Fault is a 1000-km long strike-slip fault near the northern boundary of the Plateau that has experienced five magnitude 7.0 or greater earthquakes in the past 100 years and represents a major rheological boundary. Active-source, 2-D seismic reflection/refraction data, collected as part of project INDEPTH IV (International Deep Profiling of Tibet and the Himalaya, phase IV) in 2007, was used to examine the structure and the dip of the Kunlun fault. The INDEPTH IV data was acquired to better understand the tectonic evolution of the northeastern Tibetan Plateau, such as the far-field deformation associated with the continent-continent collision and the potential subduction of the Asian continent beneath northern Tibet. Seismic reflection common depth point (CDP) stacks were examined to look for reflectivity patterns that may be associated with faulting. A possible reflection from the buried North Kunlun Thrust (NKT) is identified at 18-21 km underneath the East Kunlun Mountains, with an estimated apparent dip of 15°S and thrusting to the north. Minimally-processed shot gathers were also inspected for reflections off near-vertical structures such as faults and information on first-order velocity structure. Shot offset and nearest receiver number to reflection was catalogued to increase confidence of picks. Reflections off the North Kunlun (NKF) and South Kunlun Faults (SKF) were identified and analyzed for apparent dip and subsurface geometry. Fault reflection analysis found that the North Kunlun Fault had an apparent dip of approximately 68ºS to an estimated depth of 5 km, while the South Kunlun Fault dipped at approximately 78ºN to an estimated 3.5 km depth. Constraints on apparent dip and

Stafford fault system: 120 million year fault movement history of northern Virginia

Science.gov (United States)

Powars, David S.; Catchings, Rufus D.; Horton, J. Wright; Schindler, J. Stephen; Pavich, Milan J.

2015-01-01

The Stafford fault system, located in the mid-Atlantic coastal plain of the eastern United States, provides the most complete record of fault movement during the past ~120 m.y. across the Virginia, Washington, District of Columbia (D.C.), and Maryland region, including displacement of Pleistocene terrace gravels. The Stafford fault system is close to and aligned with the Piedmont Spotsylvania and Long Branch fault zones. The dominant southwest-northeast trend of strong shaking from the 23 August 2011, moment magnitude Mw 5.8 Mineral, Virginia, earthquake is consistent with the connectivity of these faults, as seismic energy appears to have traveled along the documented and proposed extensions of the Stafford fault system into the Washington, D.C., area. Some other faults documented in the nearby coastal plain are clearly rooted in crystalline basement faults, especially along terrane boundaries. These coastal plain faults are commonly assumed to have undergone relatively uniform movement through time, with average slip rates from 0.3 to 1.5 m/m.y. However, there were higher rates during the Paleocene–early Eocene and the Pliocene (4.4–27.4 m/m.y), suggesting that slip occurred primarily during large earthquakes. Further investigation of the Stafford fault system is needed to understand potential earthquake hazards for the Virginia, Maryland, and Washington, D.C., area. The combined Stafford fault system and aligned Piedmont faults are ~180 km long, so if the combined fault system ruptured in a single event, it would result in a significantly larger magnitude earthquake than the Mineral earthquake. Many structures most strongly affected during the Mineral earthquake are along or near the Stafford fault system and its proposed northeastward extension.

Optimal fault signal estimation

NARCIS (Netherlands)

Stoorvogel, Antonie Arij; Niemann, H.H.; Saberi, A.; Sannuti, P.

2002-01-01

We consider here both fault identification and fault signal estimation. Regarding fault identification, we seek either exact or almost fault identification. On the other hand, regarding fault signal estimation, we seek either $H_2$ optimal, $H_2$ suboptimal or Hinfinity suboptimal estimation. By

Near-surface velocity modeling at Yucca Mountain using borehole and surface records from underground nuclear explosions

Energy Technology Data Exchange (ETDEWEB)

Durrani, B.A. [Texas Univ., El Paso, TX (United States). Dept. of Geological Sciences; Walck, M.C. [Sandia National Labs., Albuquerque, NM (United States)

1996-09-01

The Department of Energy is investigating Yucca Mountain, Nevada as a potential site for commercial radioactive waste disposal in a mined geologic repository. One critical aspect of site suitability is the tectonic stability of the repository site. The levels of risk from both actual fault displacements in the repository block and ground shaking from nearby earthquakes are being examined. In particular, it is necessary to determine the expected level of ground shaking at the repository depth for large seismic sources such as nearby large earthquakes or underground nuclear explosions (UNEs). Earthquakes are expected to cause the largest ground motions at the site, however, only underground nuclear explosion data have been obtained at the repository depth level (about 350m below the ground level) to date. In this study we investigate ground motion from Nevada Test Site underground nuclear explosions recorded at Yucca Mountain to establish a compressional velocity model for the uppermost 350m of the mountain. This model is useful for prediction of repository-level ground motions for potential large nearby earthquakes.

Near-surface velocity modeling at Yucca Mountain using borehole and surface records from underground nuclear explosions

International Nuclear Information System (INIS)

Durrani, B.A.

1996-09-01

The Department of Energy is investigating Yucca Mountain, Nevada as a potential site for commercial radioactive waste disposal in a mined geologic repository. One critical aspect of site suitability is the tectonic stability of the repository site. The levels of risk from both actual fault displacements in the repository block and ground shaking from nearby earthquakes are being examined. In particular, it is necessary to determine the expected level of ground shaking at the repository depth for large seismic sources such as nearby large earthquakes or underground nuclear explosions (UNEs). Earthquakes are expected to cause the largest ground motions at the site, however, only underground nuclear explosion data have been obtained at the repository depth level (about 350m below the ground level) to date. In this study we investigate ground motion from Nevada Test Site underground nuclear explosions recorded at Yucca Mountain to establish a compressional velocity model for the uppermost 350m of the mountain. This model is useful for prediction of repository-level ground motions for potential large nearby earthquakes

Airborne Thermal Infrared Multispectral Scanner (TIMS) images over disseminated gold deposits, Osgood Mountains, Humboldt County, Nevada

Science.gov (United States)

Krohn, M. Dennis

1986-01-01

The U.S. Geological Survey (USGS) acquired airborne Thermal Infrared Multispectral Scanner (TIMS) images over several disseminated gold deposits in northern Nevada in 1983. The aerial surveys were flown to determine whether TIMS data could depict jasperoids (siliceous replacement bodies) associated with the gold deposits. The TIMS data were collected over the Pinson and Getchell Mines in the Osgood Mountains, the Carlin, Maggie Creek, Bootstrap, and other mines in the Tuscarora Mountains, and the Jerritt Canyon Mine in the Independence Mountains. The TIMS data seem to be a useful supplement to conventional geochemical exploration for disseminated gold deposits in the western United States. Siliceous outcrops are readily separable in the TIMS image from other types of host rocks. Different forms of silicification are not readily separable, yet, due to limitations of spatial resolution and spectral dynamic range. Features associated with the disseminated gold deposits, such as the large intrusive bodies and fault structures, are also resolvable on TIMS data. Inclusion of high-resolution thermal inertia data would be a useful supplement to the TIMS data.

Diverse rupture modes for surface-deforming upper plate earthquakes in the southern Puget Lowland of Washington State

Science.gov (United States)

Nelson, Alan R.; Personius, Stephen F.; Sherrod, Brian L.; Kelsey, Harvey M.; Johnson, Samuel Y.; Bradley, Lee-Ann; Wells, Ray E.

2014-01-01

Earthquake prehistory of the southern Puget Lowland, in the north-south compressive regime of the migrating Cascadia forearc, reflects diverse earthquake rupture modes with variable recurrence. Stratigraphy and Bayesian analyses of previously reported and new 14C ages in trenches and cores along backthrust scarps in the Seattle fault zone restrict a large earthquake to 1040–910 cal yr B.P. (2σ), an interval that includes the time of the M 7–7.5 Restoration Point earthquake. A newly identified surface-rupturing earthquake along the Waterman Point backthrust dates to 940–380 cal yr B.P., bringing the number of earthquakes in the Seattle fault zone in the past 3500 yr to 4 or 5. Whether scarps record earthquakes of moderate (M 5.5–6.0) or large (M 6.5–7.0) magnitude, backthrusts of the Seattle fault zone may slip during moderate to large earthquakes every few hundred years for periods of 1000–2000 yr, and then not slip for periods of at least several thousands of years. Four new fault scarp trenches in the Tacoma fault zone show evidence of late Holocene folding and faulting about the time of a large earthquake or earthquakes inferred from widespread coseismic subsidence ca. 1000 cal yr B.P.; 12 ages from 8 sites in the Tacoma fault zone limit the earthquakes to 1050–980 cal yr B.P. Evidence is too sparse to determine whether a large earthquake was closely predated or postdated by other earthquakes in the Tacoma basin, but the scarp of the Tacoma fault was formed by multiple earthquakes. In the northeast-striking Saddle Mountain deformation zone, along the western limit of the Seattle and Tacoma fault zones, analysis of previous ages limits earthquakes to 1200–310 cal yr B.P. The prehistory clarifies earthquake clustering in the central Puget Lowland, but cannot resolve potential structural links among the three Holocene fault zones.