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1

Late Quaternary tectonics and seismotectonics along the Red River fault zone, North Vietnam  

NASA Astrophysics Data System (ADS)

A study of active tectonic development in Vietnam is of great importance. Right lateral strike-slip offsets along the Red River fault during the Pliocene-present are determined by analyzing tributaries, Quaternary alluvial fans, river valley from Landsat, SPOT images, detailed topographical maps and field observation. Along the SW fault of the Red River, right lateral offsets of stream channels range between 150 and 700 m (mean offsets of 300 m). Drainage offsets (170-450 m) are found on the eastern branch. Assuming the major phase of incision is visible in this area which is close to the Red River delta due to the onset of Riss glaciation. Using the average length of offset channels and a minimum rate of 100-150 mm/yr for river propagation, we estimate the horizontal slip rates of 2.9 ± 1.7 mm/yr for Song Chay fault, 2.3 ± 1.5 mm/yr for Red River left side fault and 2.1 ± 1.5 mm/yr for Red River left side fault. Several active faults associated with it are observed in Son La area. The Phong Tho-Nam Pia fault is clearly seen in the geomorphology which separates Tu Le and Song Da rift zones. In normal fault segments striking NW-SE, SW dipping is observed clearly from SPOT images. In the field, triangular facets indicate typical dip slip displacement. Based on different data, vertical slip rate of Phong Tho-Nam Pia fault is estimated to be 0.2-0.4 mm/y for Pliocene-present, 0.5-3 mm/y for Quaternary-present and 0.6-1.7 for the present time. Based on various methods, maximum credible earthquakes for different fault segments in Vietnam were estimated.

Phan Trong Trinh; Ngo Van Liem; Nguyen Van Huong; Hoang Quang Vinh; Bui Van Thom; Bui Thi Thao; Mai Thanh Tan; Nguyen Hoang

2012-09-01

2

DEM Simulated Results And Seismic Interpretation of the Red River Fault Displacements in Vietnam  

NASA Astrophysics Data System (ADS)

The Song Hong basin is the largest Tertiary sedimentary basin in Viet Nam. Its onset is approximately 32 Ma ago since the left-lateral displacement of the Red River Fault commenced. Many researches on structures, formation and tectonic evolution of the Song Hong basin have been carried out for a long time but there are still remained some problems that needed to put into continuous discussion such as: magnitude of the displacements, magnitude of movement along the faults, the time of tectonic inversion and right lateral displacement. Especially the mechanism of the Song Hong basin formation is still in controversy with many different hypotheses due to the activation of the Red River fault. In this paper PFC2D based on the Distinct Element Method (DEM) was used to simulate the development of the Red River fault system that controlled the development of the Song Hong basin from the onshore to the elongated portion offshore area. The numerical results show the different parts of the stress field such as compress field, non-stress field, pull-apart field of the dynamic mechanism along the Red River fault in the onshore area. This propagation to the offshore area is partitioned into two main branch faults that are corresponding to the Song Chay and Song Lo fault systems and said to restrain the east and west flanks of the Song Hong basin. The simulation of the Red River motion also showed well the left lateral displacement since its onset. Though it is the first time the DEM method was applied to study the deformation and geodynamic evolution of the Song Hong basin, the results showed reliably applied into the structural configuration evaluation of the Song Hong basin.

Bui, H. T.; Yamada, Y.; Matsuoka, T.

2005-12-01

3

Red River and associated faults, Yunnan Province, China: Quaternary geology, slip rates, and seismic hazard  

Microsoft Academic Search

The 9OO-km-long right-slip Red River fault of southernmost China and northern Vietnam is a profound structural discontinuity that is me­ chanically associated with the collision of the Indian and Eurasian plates. Although history records no large earthquakes resulting from slippage along at least the principal segment of the fault in China, youthful landforms and disruptions of young sedimentary rocks indicate

C. R. ALLEN; A. R. GILLESPIE; HAN YUAN; K. E. SIEH; ZHANG BUCHUN; ZHU CHENGNAN

1984-01-01

4

Late Cenozoic tectonics of the Red River Fault Zone, Vietnam, in the light of geomorphic studies  

Microsoft Academic Search

The main episode of Pliocene-Quaternary tectonic activity in the Red River Fault Zone in Vietnam was related to dextral strike-slip motions while uplift of the SW and NE sides of the fault zone was limited. In the Vietnamese segment of this zone, traces of pre-Pliocene mature relief were preserved to a much smaller extent compared to those in Yunnan Province,

Witold Zuchiewicz; Nguyen Quoc Cuong; Jerzy Zasadni; Nguyen Trong Yem

5

Late Cenozoic tectonics of the Red River Fault Zone, Vietnam, in the light of geomorphic studies  

NASA Astrophysics Data System (ADS)

The main episode of Pliocene–Quaternary tectonic activity in the Red River Fault Zone in Vietnam was related to dextral strike-slip motions while uplift of the SW and NE sides of the fault zone was limited. In the Vietnamese segment of this zone, traces of pre-Pliocene mature relief were preserved to a much smaller extent compared to those in Yunnan Province, China. The main factors controlling headward erosion of tributary streams were lithologic contrasts within the solid bedrock. Tectonic-geomorphic studies indicate that the amount of Quaternary dextral offset of the Red River Fault Zone in Vietnam, calculated from offset and deflection of tributary valleys of the Red River, ranges between some 400 m and 5.3 km, averaging 1.1–2 km. The corresponding rates of slip are 0.43–1.1 mm/yr for individual displaced segments and 5.5–7.8 mm/yr for the inferred cumulative displacement. Fluvial terraces in the medial segment were mainly shaped in the Late Pleistocene and Holocene, except the highest one (40–50 m) which was probably formed in Mid-Pleistocene time. Taking into account the amount of dextral displacement of terrace steps and related alluvial fans, the most realistic estimation of Mid-Pleistocene through Holocene slip rate is 0.9–3.9 mm/yr. The axis of maximum horizontal compression associated with dextral slip of the fault zone was aligned NNW–SSE to N–S, and the fault motion in the Quaternary resulted mainly from aseismic creep.

Zuchiewicz, Witold; Cu’ò’ng, Nguy?n Qu?c; Zasadni, Jerzy; Yêm, Nguy?n Tr?ng

2013-09-01

6

Formation mechanism of the Qiongdongnan basin northwest of the South China Sea-dating the sinistral slip of the Red River Fault Zone  

NASA Astrophysics Data System (ADS)

Locating on the northwestern margin of the South China Sea, the Qiongdongnan basin is a NE-trending rift zone in general. Bounding with the NW-trending Yinggehai basin and the Red River- East Vietnam Fault Zone to the west, the evolution of the Qiongdongnan basin bears large amounts of information about the slip of the Red River Fault zone. Combined the geological analysis with analogue modeling experiments, we suggest that the evolution of the Qiongdongnan is controlled not only by the southeastward to south southeastward extension, but also by the sinistral slip of the Red River Fault zone. The central depression of the Qiongdongnan basin is controlled mainly by the southeastward to south southeastward extension, while the southern depression developed under the combined stress filed of southeastward extension and the dextral slip along the NNW-trending Red River fault zone. The northern depression was formed by the combined effect of the sinistral slip along the Red River Fault Zone and the southeastward extension. According to the age of the shear fault starting to develop in the southwest of the Qiongdongnan basin, as well as the age for the northwestern part to develop, the sinistral slip of the Red River Fault zone began around early oligocene, later than the rifting of the Qiongdongnan basin. The sinistral slip rate of the Red River Fault zone during early Oligocene may be smaller than the displacement rate of the Qiongdongnan basin, but become reversed thereafter, which in turn caused tectonic inversion and folding along the western segment of the Qiongdongnan basin, and NW- to NNW-trending Rediel faults from late Oligocene to middle Miocene. Through the deformation history of the Qiongdongnan basin, we defined the sinistral slip stage Indochina along the Red River Fault zone from about 36Ma to 16Ma, and further a rapid slip occurring after 30Ma.

Sun, Z.; Jiang, J.; Xie, W.

2010-12-01

7

Extensional step-over between the Zhongdian and Red River faults: kinematics of the Daju normal fault constrained by cosmogenic dating of the Yangtze terraces (Yulong Shan, Yunnan)  

NASA Astrophysics Data System (ADS)

Extension in western Yunnan, southeastern Tibet, is limited by two dextral strike-slip faults, the Zhongdian and Red River faults, to the north and south, respectively, and is characterized by N-S directed normal faults and basins. In the northwestern corner of this large extensional step-over, the Yangtze River crosses the Daju normal fault at the foot of the Yulong Shan. Due to uplift of the Yulong Shan, the Yangtze carved the huge Huxiao Jia (Tiger Leap) Gorges (˜3500 m deep) and abandoned sets of fluvial terraces across the fault zone and in the Daju basin to the north. Cosmogenic dating of blocks sampled on top of the terraces provide ages ranging from 8 to 30 ka. In the hanging wall basin to the north, the terraces may have been abandoned after the breach of a natural dam formed in the river (moraine or landslide) during the last glacial period. The average incision rate of the river in the basin is about 5.9 mm/yr, the vertical slip-rate on the Daju fault is 4.9±1.3 mm/yr, thus implying an incision rate of the river inside the gorge reaching about 11 mm/year. These rates may explain the exceptional size and steepness of the gorge. These results show that active faulting plays a major role in shaping the present relief of this region and that recent strain changes involve movement along the largest strike-slip faults of the region, in accordance with models implying large-scale block extrusion.

van der Woerd, J.; Perrineau, A.; Gaudemer, Y.; Leloup, P.-H.; Liu-Zeng, J.; Barrier, L.; Thuizat, R.

2012-04-01

8

Displacement along the Red River Fault constrained by extension estimates and plate reconstructions  

NASA Astrophysics Data System (ADS)

Significant E-W extension and/or compression must have been generated by displacements along the Red River Fault (RRF) since its curvature does not match a small circle centered at the Euler pole for the Indochina-south China plate pair. The amount of extension perpendicular to the RRF offshore Vietnam depends on the magnitude of left-lateral displacement along the RRF. In general, the larger the left-lateral displacement along the fault, the smaller the amount of E-W extension. All purely strike-slip models of the opening of the South China Sea that assume large displacements (>250 km) along the RRF encounter major problems because they imply little extension, or even considerable shortening, offshore east Vietnam. This is inconsistent with the presence of large elongated basins offshore Vietnam. Using a plate tectonic model, we compare continental extension values implied by different magnitudes of displacement along the RRF with crustal stretching estimates derived from 2-D profiles modeled from gravity data. We utilize 2-D gravity forward models to restore the extended continental margin crust to its original position prior to extension. We find that substantial amounts of extension for offshore Vietnam can only be modeled assuming moderate displacements along the RRF compatible with the presence of a southward subducting proto-South China Sea. The total amount of ENE-WSW extension offshore northern Vietnam constrained by our 2-D gravity profiles and gravity inversion increases southward from 36 to 89 km along the Yinggehai Basin. These values of ENE-WSW extension are consistent with 250 km of left-lateral displacement along the RRF.

Mazur, S.; Green, C.; Stewart, M. G.; Whittaker, J. M.; Williams, S.; Bouatmani, R.

2012-10-01

9

Lithofacies and depositional environments of Miocene deposits from tectonically-controlled basins (Red River Fault Zone, northern Vietnam)  

Microsoft Academic Search

The Lao Cai, Yen Bai and Bao Yen Basins connected with the Red River Fault Zone (RRFZ) are filled with over 1000m thick Neogene (Miocene) clastic deposits of different type and origin. Coarse-grained alluvial deposits predominate along the south-western margin of the Lao Cai and Yen Bai Basins, while different types of conglomerates and sandstones, even siltstones occur in their

Anna Wysocka; Anna ?wierczewska

2010-01-01

10

Potassic magma genesis and the Ailao Shan-Red River fault  

NASA Astrophysics Data System (ADS)

Two types of K-rich magma of Eocene to Early Oligocene (ca. 40-30) and Plio-Pleistocene (ca. 5-0.1 Ma) age were emplaced prior to and following left-lateral slip on the Ailao Shan-Red River (ASRR) fault, a regional shear zone extending between southwest China and the Tonkin Gulf (South China Sea) that accommodated 'escape' of the Indochina block. The first type is exposed in the Dali-Lijiang and adjacent regions of western Yunnan and Sichuan and comprises ultramafic potassic to ultrapotassic 'absarokites' and their shoshonite, banakite, and SiO2-rich derivatives which were emplaced immediately prior to activation of the ASRR fault. They are characterized by high Mg.-nos, and low contents of fusible oxides (FeO*, CaO, Al2O3), for equivalent MgO content, and pronounced primitive mantle-normalized high-field strength element (HFSE) depletions. In contrast, 'post-escape' K-rich magmas were erupted in the Puer, Maguan-Pingbian regions of south and southeast Yunnan. Apart from their relative enrichments in potassium they show typical HFSE-rich intra-plate compositional affinity. Geological and geomorphic evidence, and thermochronologic age dating of metamorphisc events, suggest that left-lateral shearing occurred between ca. 30 and 17 Ma; thereby accommodating the southeastward 'escape' of Indochina and (possibly) two episodes of spreading in the South China Sea. The southwestern part of Dali-Lijiang magmatic products was detached and offset by ca. 600 km and are now located in Phan Xi Pang in northern Viet Nam. The same is true for the Permo-Triassic Emeishan flood basalts, whose western exposures were likewise displaced by the same amount and are now represented by the Song Da complex, also in northern Viet Nam. Here, we report geochemical, isotopic, and 40Ar/39Ar age data for samples from both the 'pre-escape' Dali-Lijiang magmas and the 'post-escape' K-rich Puer, Maguan-Pingbian basalts and basanites, with a view to comparing and contrasting their interpolated source compositions, estimated conditions of upper mantle melt segregation and, by inference, their mantle dynamic and contamination histories insofar as these were conditioned by the India-Asia collision. Our interpretations yielded two complementary conclusions. The first contends that the pre-escape magmas result from adiabatic melting of crust-contaminated asthenosphere comprising a 'mélange' of continental lithospheric mantle (CLM) (hydrated by sab-derived hysdrous fluids released at 0.2-0.5 GPa) and lower crust, delaminated from the overriding plate during mantle wedge corner flow and further enriched by metasomatic melts of subducted continental crust. We postulate that incipient H2O-saturated melting of the 'mélange' occurs at depths of between ca. 100 and 200 km after being 'dragged' down by relict oceanic slab fragments, in response to the dehydration of supra-subduction amphibole- and phlogopite. The ensuing viscosity 'crisis' and buoyancy relative to ambient 'fertile' convecting mantle of such asthenospheric 'pockets', and the collision-related change from lithospheric compression to extension, almost certainly predisposes such a refractory yet crust-contaminated 'pockets' to rapid adiabatic melting. The second conclusion concerns the post-escape K-rich basalts and basanites and is based on the contention that decompression melting of thermally anomalous K-rich asthenospheric occurred in response to regional post-escape transtension, concomitant with the cessation Indochina escape and contiguous seafloor spreading. However, although these magmas share the HFSE-rich fertile source character of other, widely dispersed, post-escape Cenozoic basalts they more specifically resemble relatively rare examples of intra-plate, K-rich activity observed in northeast China, central Spain, and elsewhere in Asia and Europe, arguably (indirectly) reflecting mantle perturbations caused by major continental collisions.

Flower, Martin F. J.; Hoàng, Nguy?n; Lo, Chinh-hua; Chí, Cung Thu'?'ng; Cu'ò'ng, Nguy?n Qu?c; Liu, Fu-tian; Deng, Jin-fu; Mo, Xuan-xue

2013-09-01

11

Shallow faults mapped with seismic reflections: Lost River Fault, Idaho  

Microsoft Academic Search

A high-resolution seismic-reflection survey, conducted at the intersection of Arentson Gulch road and the western splay of the Lost River fault scarp in central Idaho, defines a bedrock surface about 80 m deep which is segmented by several faults forming graben structures. Six meters of total fault displacement can be interpreted on the bedrock reflector while only 1 to 2

Mubarik Ali; Richard D. Miller; Don W. Steeples

1991-01-01

12

The Ailao Shan-Red River shear zone (Yunnan, China), Tertiary transform boundary of Indochina  

Microsoft Academic Search

The Red River Fault zone (RRF) is the major geological discontinuity that separates South China from Indochina. Today it corresponds to a great right-lateral fault, following for over 900 km the edges of four narrow (A detailed study of the Ailao and Diancang Shan shows that the gneiss cores of the ranges are composed of strongly foliated and lineated mylonitic

Philippe Hervé Leloup; Robin Lacassin; Paul Tapponnier; Urs Schärer; Dalai Zhong; Xiaohan Liu; Liangshang Zhang; Shaocheng Ji; Phan Trong Trinh

1995-01-01

13

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

SciTech Connect

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

Cumbest, R.J.

2000-11-14

14

Wetland storage to reduce flood damages in the Red River  

Treesearch

Title: Wetland storage to reduce flood damages in the Red River ... sub- watersheds of the Red River Valley (the Maple River Watershed in North Dakota, and the Wild ... Keywords: land stewardship, watershed management, ecosystem -based ...

15

Red River Valley. Selected Readings. Grade Five.  

ERIC Educational Resources Information Center

Sixteen readings dating from 1854 through 1969, many of which are primary materials excerpted from dated Minnesota newspapers, are intended for fifth grade students. Five themes describe past and present conditions in the Red River Valley: 1) show the importance of fur trade and describe the wooden carts in the train that carried the trade; 2)…

Minnesota Univ., Minneapolis. Project Social Studies Curriculum Center.

16

Saline Soils in the Red River Valley  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Red River Valley of the North stretches over 315 miles from northeastern South Dakota through northwestern Minnesota and eastern North Dakota into southern Manitoba. Nearly all this area is in dryland farms and is highly productive. Salinity has been recognized as a major factor affecting crop p...

17

Life Under a Spanish Red River  

NSDL National Science Digital Library

This magazine article introduces the Rio Tinto - a polluted, acidic river in Spain - and its significance in the Mars Analog Research and Technology Experiment (MARTE). As part of NASA's search for Mars analogs, the blood-red river is an expedition target to drill for core samples and test satellite links in preparation for remote robots that might survey the red planet. The article explains that extremophiles inhabiting the Rio Tinto might be used as model systems to test for both subsurface life on Mars and sulfur-based life on Europa. It includes images of sulfide minerals and microbes found in the river, links to supplementary resources, and an MP3 audio-to-text option.

2003-04-10

18

Rates of active faulting during late Quaternary fluvial terrace formation at Saxton River, Awatere fault, New Zealand  

Microsoft Academic Search

A fl ight of faulted fl uvial terraces at Saxton River on the Awatere fault, northeast South Island, New Zealand, preserves the incremen- tal slip history and detailed paleoearthquake chronology of this major strike-slip fault. Here, six fl uvial terraces have been progres- sively displaced across the inland Molesworth section of the fault, with horizontal displace- ments ranging from ~6

Dougal P. M. Mason; Timothy A. Little; Russ J. Van Dissen

2006-01-01

19

Numerical modelling of river rearrangement along strike-slip faults  

NASA Astrophysics Data System (ADS)

Most studies of climate-tectonic interactions have focused on steady state orogens that evolve through orogen-normal convergence. Yet, most orogens have a major component of strike skip (wrenching). Although river captures occur in various kinds of geomorphic settings, they are frequently produced in such orogens by strike-slip faulting. The impacts of river captures are not well quantified because compelling diagnostic features and good quality proximal records are rarely found. We have modified the CASCADE numerical surface-process model to incorporate horizontal motion across a strike-slip fault and to study the evolution of drainage organization. Two river geometries are used to study the effect of horizontal movement on drainage systems. (1) The first simulates the deformation of an isolated crosswise stream. The continued horizontal displacement of streams leads to stream deflection and formation of a deep valley along the fault. The elongation of the river is not limited by the presence of other streams, and the lengthening process lowers river gradients and likely diminishes the river’s erosional efficiency. The ratio between uplift and strike-slip rates controls the response of drainage systems. We define two extreme cases (i) with a low ratio, the river presents a flat profile along the fault and a knick-point at a gorge outlet where the river leaves the fault; further work is in progress to test the influence of different parameters on the position of the knick-point; (ii) with a high ratio, catchment uplift compensates the horizontal elongation of the river. The river keeps the same profile. The system remains in steady-state. (2) The second geometry simulates two parallel crosswise rivers. In this case, lenghtening ends when drains are brought into contact by strike-slip faults. The physical barrier between them is tectonically removed. Our models show an expected transient increase in local relief and therefore basin incision. Through elongation and capture, deformation in a wrench zone produces a constantly evolving pattern of stream reaches with various incision rates. Drainage basins located upstream from the wrench zone experience a series of sudden captures and longer intervening periods of lengthening and slowing erosion. This results in oscillations in incision rate and internal drainage adjustments. Erosion and landscape, in these wrenched systems, thus operate in permanent disequilibrium.

Brocard, G. Y.; Simon-Labric, T.; van der Beek, P.; Teyssier, C.

2009-12-01

20

Water resources of Red River Parish, Louisiana  

USGS Publications Warehouse

Red River Parish is on the eastern flank of the Sabine uplift in northwestern Louisiana. The 'area is underlain by lignitic clay and sand of Paleocene and Eocene age which dip to the east at the rate of about 30 feet per mile. The Red River is entrenched in these rocks in the western part of the parish. Alternating valley filling and erosion during the Quaternary period have resulted in the present lowland with flanking terraces. In the flood-plain area moderate to large quantities of very hard, iron-bearing water, suitable for irrigation, are available to wells in the alluvial sand and gravel of Quaternary age. The aquifer ranges in thickness from 20 to slightly more than 100 feet. It is recharged by downward seepage of rainfall through overlying clay and silt, by inflow from older sands adjacent to and beneath the entrenched valley, and by infiltration from the streams where the water table is below stream level during flood stages or as a result of pumping. Water levels are highest in the middle of the valley. Ground water moves mainly toward the Red River on the east and Bayou Pierre on the west, but small amounts move down the valley. Computations based on water-level and aquifer-test data indicate that the Quaternary alluvium contains more than 330 billion gallons of ground water in storage and that the maximum discharge of ground water to the streams is slightly more than 30 mgd (million gallons per day). At times of high river stage, surface water flows into the aquifer at a rate that depends in part upon the height and duration of the river stage. Moderate supplies of soft, iron-bearing water may be obtained from dissected Pleistocene terrace deposits that flank the flood plains of the Red River and Black Lake Bayou. However, the quantity of water that can be pumped from these deposits varies widely from place to place because of differences in the areal extent and saturated thickness of the segments of the deposits; this extent and thickness are governed in turn by the amount of erosion the deposits have undergone. Beds of fine-grained lignitic sands of Tertiary age contain water of generally good quality to depths of 150 to 450 feet. The thinness and low permeability of the sands restrict their development to low-yield wells. Water from these sands in the western part of the parish, where they lie beneath the alluvial valley, is more mineralized than that from the younger Tertiary sands exposed in the east-central area. Streamflow records have been collected on the principal streams in Red River Parish since 1939. Additional spot low-flow data were obtained on several small streams originating within the parish for a study made in connection with the preparation of this report. Quality-of-water data for streams in the parish were collected on an occasional spot-sampling basis prior to and during this investigation. The largest source of surface water in the parish is the Red River, which drains approximately 63,400 square miles upstream from the parish. The Red River has an average flow of about 13,100 cfs (cubic feet per second), or about 8,500 mgd. Many of the streams that drain the upland area are not dependable sources of supply because their flows are not well sustained during dry seasons. The average annual precipitation over the parish is about 52 inches, of which about 17 inches becomes runoff; this runoff is equivalent to a continuous flow of about 1.25 cfs per square mile. Seasonal and annual runoff varies, but no significant trends have been noticed. The principal surface-water problems in the parish pertain to flood control, drainage, irrigation, and navigation. Flood problems have been alleviated considerably by the operation of Denison Dam (Lake Texoma), the completion of levees on the Red River, channel improvements on Bayou Pierre, and the completion of Wallace Lake reservoir on Cypress Bayou. There are wet lands along the Red River that would be very productive if properly drained

Newcome, Roy; Page, Leland Vernon.

1963-01-01

21

33 CFR 207.380 - Red Lake River, Minn.; logging regulations for portion of river above Thief River Falls.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Red Lake River, Minn.; logging regulations for...NAVIGATION REGULATIONS § 207.380 Red Lake River, Minn.; logging regulations for...a) Parties wishing to run logs on Red Lake River must provide storage booms...

2013-07-01

22

River Captures and Erosional Disequilibrium Along Strike-slip Faults  

NASA Astrophysics Data System (ADS)

River captures are internal instabilities of erosion systems and are inherently promoted by strike-slip faulting. A capture event can generate a wave of incision that propagates from the capture site upstream and/or downstream, resulting in an increased bulk erosion rate around the capture site. Thus, under steady boundary conditions, drainage diversions trigger pulses of erosion, sediment production, rock exhumation and isostatic rebound. Therefore, a significant part of the erosion in oblique tectonics can be achieved in a state of significant departure from short-term dynamic equilibrium. The frequency, intensity, and duration of these events set the timescale over which their integrated effects can be regarded as the expression of a long-term dynamic equilibrium. We are investigating the effects of a large river capture on the oblique collision between the North American and Caribbean plates in Guatemala. Several thousands of kilometers of strike-slip displacement have been accommodated along this boundary during the Tertiary. The deformation is now concentrated mostly along the E-W Motagua strike-slip fault. Oblique tectonics is discernable within a 50 km wide topographic belt, north of this fault (Sierra de las Minas - Sierra de Chuacus range). On the northern flank of this range, deformation includes 130 km offset across the Polochic strike-slip fault, documented by both geological structures and drainage patterns. Numerous elbows and dry valleys show the progressive transformation of the initial transverse (S-N) drainage crossing the fault into a transverse-parallel (E-W) system that developed during increasing displacement along the fault. The drainage reorganization operates by river lengthening, captures, and avulsions. One of the latest capture sites is surrounded by a large (110x30 km) zone of deeply (1500 m) dissected landscape that coincides with the captured catchment. This zone sharply contrasts with the surrounding areas where large fragments of a very subdued topography are preserved on the highlands. The capture has been interpreted as the diversion of the former headwaters of a westward flowing river located south of the fault (Rio Selegua) into a northward flowing river located north of the fault (Rio Chixoy), based on drainage pattern and preserved conglomerates. The capture event, the dissection of the landscape, and the uplift of the summit paleosurface are closely related, and likely Miocene in age. Newly discovered conglomerates confirm that the captured basin was drained by the Selegua River before being drained into the Chixoy River. Other newly discovered paleovalleys and conglomerates further document the expansion of the dissected captured watershed at the expense of surrounding catchments. Since the capture event, both the captured stream paleovalley and the subdued topography have been displaced by large normal faults, many of them striking parallel to the Polochic strike-slip fault. Recent faulted sediments on the Polochic Fault trace also display a significant vertical component of slip. The inception of this tectonic activity after the abandonment of the paleovalleys suggests that the faults may have accommodated the isostatic uplift that followed unloading of the captured drainage basin by erosion.

Brocard, G. Y.; Fayon, A. K.; Perg, L. A.; Paola, C.; Teyssier, C.; Whitney, D. L.; Mota, M.; Moran-Ical, S.

2005-12-01

23

Numerical modelling of river reorganization along strike-slip faults  

NASA Astrophysics Data System (ADS)

Most studies of climate-tectonic interactions have focused on steady state orogens that evolve through orogen-normal convergence. Yet, most orogens have a major component of strike skip (wrenching). Although river captures occur in various kinds of geomorphic settings, they are frequently produced in such orogens by strike-slip faulting. The impacts of river captures are not well quantified because compelling diagnostic features and good quality proximal records are rarely found. CASCADE numerical simulation code (Braun and Sanbridge, 1997) has been modified to model horizontal motion across a strike-slip fault and to witness the evolution of river drainage organization. Two river geometries are used to study the effect of horizontal movement on river drainage system. (1) The first one simulates the deformation of an "isolated crosswise stream". The continued horizontal displacement of streams leads to stream deflection and formation of a deep valley along the fault. The elongation of the river is not limited by the presence of other streams, and the lengthening process lowers river gradients and likely diminishes the river's erosional efficiency. (2) The second geometry simulates two parallel crosswise rivers. In this case, lenghtening ends when drains are brought into contact by strike-slip faults. The physical barrier between them is tectonically removed. Further work is in progress to test the influence of capture on the basin incision. First results seem to show an expected transient increase in local relief and therefore basin incision. Through elongation and capture, deformation in a wrench zone produces a constantly evolving pattern of stream reaches with various incision rates. Drainage basins located upstream from the wrench zone experience a series of sudden captures and longer intervening periods of lengthening and slowing erosion. This results in oscillations in incision rate and internal drainage adjustments. Erosion and landscape, in these wrenched systems, thus operate in permanent disequilibrium. Braun, J. and Sambridge, M., 1997, Modelling landscape evolution on geologic time scales: a new method based on irregular spatial discretization, Basin Research, v.9, pp.27-52.

Simon-Labric, T.; van der Beek, P.; Teyssier, C.; Brocard, G.

2009-04-01

24

Seismo-tectonics of the Red Sea region in Eritrea: the case of the "transform faults"  

NASA Astrophysics Data System (ADS)

Eritrea is located in the vicinity of the three well recognized seismically active Cenozoic tectonic features in the Horn of Africa, namely, the Red Sea, the East African rift system, and the Gulf of Aden. Within Eritrea, the major seismic source zones identified include: (1) the western margin of the Afar rift, (2) the escarpment, (3) the Massawa channel, (4) the axial trough of the southern Red Sea, (5) the NNW-SSE lineament that connects northern Afar to the axial trough of the Red Sea, and (6) two E-W lineaments that extend onshore from the Red Sea into the Eritrean escarpment. In previous studies the above lineaments have been considered to represent transform faults. However, the absence of well-developed oceanic ridge in the Eritrean segment of the Red Sea and the very low angle (<45) between the orientations of the NNW-SSE lineament and the incipient spreading axis of the Red Sea defy present-day transform fault examples. Fault plane solutions and field observations corresponding to this lineament suggest an E-dipping oblique fault with movement of the hanging wall to the south-east. Similarly, the E-W lineaments, despite being perpendicular to the spreading axis of the Red Sea are characterized by fault plane solutions indicative of normal faults. Fault orientation data (fault plane-striation pair) from these faults also confirm this conclusion and suggest a dip-slip normal fault with hanging wall movement to the south. The lineaments are therefore sites of active normal fault deformation, but not transform faults.

Woldehaimanot, B.; Haileab, B.

2005-12-01

25

Seismic Reflection Project Near the Southern Terminations of the Lost River and Lemhi Faults, Eastern Snake River Plan, Idaho.  

National Technical Information Service (NTIS)

Thirteen seismic reflection lines were processed and interpreted to determine the southern terminations of the Lost River and Lemhi faults along the northwest boundary of the eastern Snake River Plain (ESRP). The southernmost terminations of the Arco and ...

G. S. Carpenter J. L. Casper R. P. Smith S. M. Jackson

2006-01-01

26

93. (Credit CBF) Red River syphon running along the southern ...  

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

93. (Credit CBF) Red River syphon running along the southern shore of Douglas island, adjacent to Cross Bayou, March 1913. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

27

Program Review. Missouri-Souris-Red River Basin Comprehensive Project.  

National Technical Information Service (NTIS)

The study plan represents background material required for a program review of the Missouri-Souris-Red River Basins Project. It contains information relative to budget, personnel, administrative and operational procedures likely to be encountered during t...

1966-01-01

28

Fault patterns in Benin River and Makaraba Fields: A regional play type for the Niger Delta  

SciTech Connect

Using 830 km{sup 2} of excellent 3-D seismic data, we determined the fault patterns that are responsible for hydrocarbon entrapment in the Benin River and Makaraba fields, onshore northwestern Niger Delta. Both fields are trapped downthrown to the major listric GbokoMaka growth fault system, which trends E18{degrees}S for over 40 km, and has at least 2000 m of displacement to the southwest. Several major splay faults break off the main trend in a southeasterly direction, creating a series of fault-bounded structural compartments. Each of these compartments opens to the southeast and has a structural attic at the junction of the splay fault with the main fault trend. These compartments create large-scale traps for hydrocarbons migrating from east to west up the gentle regional dip within the Miocene Ughelli depobelt. The Benin River field is trapped in the major compartment between the GbokoMaka fault and the Benin River splay fault. The large Makaraba field is similarly trapped between the GbokoMaka and MakaWest faults. Such traps require an upthrown fault seal at the master fault and a downthrown fault seal at the splay fault. In the Makamba field, the trap potential is enhanced by rollover into the GbokoMaka fault. The same structural style is also evident along several other major fault trends to the north and the south, and probably represents an important play type in the onshore western Niger delta.

Adeyekun, A.B.; Faparusi, B.D.; Nunns, A.G. [Chevron Nigeria Ltd., Lagos (Nigeria)] [and others

1995-08-01

29

Fault Tree Analysis of System Anomaly Leading to Red Oil Explosion in Plutonium Evaporator  

Microsoft Academic Search

Results of scenario identification, preparation of reliability data, fault tree construction and its analysis, are rendered for a system anomaly considered liable to lead to a red oil explosion in a Pu evaporator of a typical model of reprocessing facility.Japan Atomic Energy Research Institute has introduced the model plant data, the basic failure frequency data together with the fault tree

Yasushi NOMURA; Rolf LEICHT; Philip ASHTON

1994-01-01

30

Evaluating the evolution of the Red River system based on in situ U-Pb dating and Hf isotope analysis of zircons  

NASA Astrophysics Data System (ADS)

The Red River originates from SW China and SE Tibet and has a total length >1000 km. In this study, we present new U-Pb dating and Hf isotopic analysis of zircon grains, from both modern and paleoriver sands in order to constrain the provenance of the modern river and to decipher drainage evolution through time. Our data show that the Yangtze and Songpan Garze blocks are the most important sources for sediment, although this material is mostly reworked via younger sedimentary rocks in the upper reaches of the Red River. Sands in the Da River and to a lesser extent the Lo River have zircon ages indicating that they are minor contributors to the net flow, consistent with rock uplift, which is strongest in the upper reaches of the Red River, rather than precipitation being the primary control on erosion. Sediments eroded from the metamorphic rocks along the Red River Fault Zone appear to have made a greater contribution during the Miocene. Zircon ages suggest that the Red River flowed north of the Day Nui Con Voi in the Middle-Late Miocene. The Red River appears to have had a largely stable provenance since at least the Late Miocene. Upper Miocene sedimentary rocks NE of the Red River indicate the presence of a separate, large river in the Late Miocene. Hf isotope data indicate that the Irrawaddy River was never part of the Red River system. Although we do not exclude the Salween, Mekong, and Yangtze rivers from having been part of the Red River, any connection must have been pre-Middle Miocene.

van Hoang, Long; Wu, Fu-Yuan; Clift, Peter D.; Wysocka, Anna; Swierczewska, Anna

2009-11-01

31

Deep-fault connection characterization from combined field and geochemical methodology; examples from Green River and Haiti fault systems  

NASA Astrophysics Data System (ADS)

Fault transfer properties are depending on different parameters, such as fault plane geometry, regional to local offset guiding the morphology through time, but are also very sensitive on other factors which may vary through time and space. Detailed along-strike observations and analyses of the Green River Fault system (Utah) outline the strong impact of several parameters; pre-existing structures or basement heterogeneities, lateral variation of the host-rock mechanical properties, the change of paleostress field through time which creates complex fault intersections. This last parameter, is often associated either with along-and-across fluid drainage (fault leaking) or with abnormal sealing deformation and uplifts corresponding to the locked fault segments. Along the Green River anticline, which is dissected by Salt wash and Little Grand wash major faults, several leaking segments are distributed. They have been analysed for geochemical characterization. In fact, carbon dioxide rich waters expelled from natural or artificial (well-driven geyser) springs, are located preferentially at structural intersection points. Changes in fault transfer properties has been proved as discontinuous from detailed datings (U/Th datings: see Frery et al AGU 2011 this meeting) on the top-fault travertines precipitation. The correlation with fault mineralisation at depth is still under investigation. In this area, not considered as very seismic one compared to the adjacent Basin and Ranges area, fault activity relates both on slow processes indicating a long seismic recurrence time, and on local reservoir short-time de-pressurisation processes. The same methods of investigation will be used on the very active Haitian fault system. The new constraints applied on the Enriquillo-Plantain-garden Fault (EPGF) responsible for the initial deep tectonic stress release (12 January 2010), have not been expressed by a clear surface fault rupture (surface locked segment), but by a northward widening of the impacted zones indicating a strong partitioning of the deformation. The resulting stress re-location is well expressed by (1) the dispersion of the aftershocks, essentially North of the strike-slip fault, (2) a progressive local uplift on the hanging wall, and (3) by along-fault fluid flow variation (leaking segments) either along the EPGF recently active segments but also around the Cul-de-Sac plain. As a first approach, we focus our attention on fault-related fluid leakage distribution, located at intersection points between strike-slip and compressive faults. Using this combined approach, mixing structural and geochemical analytical work, we will hopefully be able (i) to identify the transient and permanent fault activity, and (ii) to characterize the time recurrence (if any) and (iii) the location of the seismic activity during the Quaternary in this two natural analogues.

Nadine, E. Z.; Frery, E.; Leroy, S.; Mercier De Lepinay, B. F.; Momplaisir, R.

2011-12-01

32

Williston basin Red River Formation: exploration success, development failure  

Microsoft Academic Search

Hydrocarbon reserves in Red River limestones are typically found in porosity zones created by paragenetic dolomitization and diagenetic calcite solution and microfacturing. The porosity developed on the tops and flanks of low-relief carbonate highs in a shallow marine environment. Since basement structure and topography controlled the location and limits and porosity development, an attempt was made to reconstruct Ordovician topography

Johnson

1983-01-01

33

Red Oil Explosions at the Savannah River Plant.  

National Technical Information Service (NTIS)

Two red-oil explosions occurred at the Savannah River Plant. The first of these was in an evaporator at the semiworks prior to plant operation. The second occurred 22 years later in an A-Line facility calciner (called a denitrator). (ERA citation 09:01826...

W. S. Durant

1984-01-01

34

95. (Credit CBF) Red River syphon line cross Cross Bayou, ...  

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

95. (Credit CBF) Red River syphon line cross Cross Bayou, March 1913. The new low service pump pit and the receiving well for the syphon are in the background. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

35

94. (Credit CBF) Red River syphon line crossing Cross Bayou, ...  

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

94. (Credit CBF) Red River syphon line crossing Cross Bayou, March 1913. The new low service pump pit and the receiving well for the syphon are in the background. - McNeil Street Pumping Station, McNeil Street & Cross Bayou, Shreveport, Caddo Parish, LA

36

78 FR 62359 - Red River Hydro LLC; Notice of Availability of Final Environmental Assessment  

Federal Register 2010, 2011, 2012, 2013

...Number 203 (Monday, October 21, 2013)] [Notices...Project No. 13160-004] Red River Hydro LLC; Notice...Projects has reviewed Red River Hydro LLC's application...would be located on the Red River in Rapides Parish...ferc.gov. Dated: October 11, 2013....

2013-10-21

37

Faults  

NSDL National Science Digital Library

This site explains the three types of faults that result from plate movement. Animated diagrams are used to demonstrate strike-slip faults, normal faults, and reverse faults. There are also four photographs that show the results of actual earthquakes.

38

Seismic Reflection Project Near the Southern Terminations of the Lost River and Lemhi Faults, Eastern Snake River Plain, Idaho  

SciTech Connect

Thirteen seismic reflection lines were processed and interpreted to determine the southern terminations of the Lost River and Lemhi faults along the northwest boundary of the eastern Snake River Plain (ESRP). The southernmost terminations of the Arco and Howe segments were determined to support characterization of the Lost River and Lemhi fault sources, respectively, for the INL probabilistic seismic hazard analysis. Keywords:Keywords are required forExternal Release Review*Keywords  Keywords *Contacts (Type and Name are required for each row) Type ofContactContact Name  POC Editor RecordFour commercial seismic reflection lines (Arco lines 81-1 and 81-2; Howe lines 81-3 and 82-2) were obtained from the Montana Power Company. The seismic data were collected in the early 1980’s using a Vibroseis source with station and shot point locations that resulted in 12-fold data. Arco lines 81?1 and 81?2 and Howe lines 81?3 and 82?2 are located within the basins adjacent to the Arco and Howe segments, respectively. Seven seismic lines (Arco lines A1, A2, A3, and A4 and Howe lines H1, H2, and H3) were acquired by EG&G Idaho, Inc. Geosciences for this study using multiple impacts with an accelerated weight drop source. Station and shot point locations yielded 12-fold data. The seismic reflection lines are oriented perpendicular to and at locations along the projected extensions of the Arco and Howe fault segments within the ESRP. Two seismic lines (Arco line S2 and Howe line S4) were obtained from Sierra Geophysics. In 1984, they acquired seismic reflection data using an accelerated weight drop source with station and shot point locations that yielded 6-fold data. The two seismic reflection lines are oriented perpendicular to and at locations along the projected extensions of the Arco and Howe fault segments within the ESRP. In 1992 for this study, Geotrace Technologies Inc. processed all of the seismic reflection data using industry standard processing techniques. The southern termination of the Howe segment of the Lemhi fault was placed between Howe lines H1 and H2, 2.2 km south of the fault’s southernmost surface expression. In the adjacent basin, south-dipping normal faults at the northern end of Howe line 81-3 and two southwest-dipping normal faults at the northeastern end of Howe line 82-2 that can be correlated with Howe segment. South of the surface expression, two southwest-dipping normal faults on Howe line H1 can be correlated with the Howe segment. Further into the ESRP, Howe lines H2, H3, and S4 show continuous flat lying reflectors and indicate no fault offset. The southern termination of the Arco segment of the Lost River fault was placed between Arco lines S2 and A3, a distance of 4.6 km south of the fault’s southernmost surface expression. Within the basin, west-dipping normal faults interpreted on Arco lines 81-1 and 81-2 can be correlated with the Arco segment. Further south within the Arco volcanic rift zone (VRZ), three seismic lines (Arco lines A2, S2, and A3) permit two interpretations. The west- and south-dipping normal faults on Arco lines A2 and S2 could be associated with slip along the Arco segment. These normal faults have an opposite dip to an east-dipping fault on Arco line A3. The observed small-offsets (< 85 m) along the oppositely dipping normal faults can be interpreted as a graben structure that resulted from dike intrusion within the Arco VRZ. Arco line A4 further south within the Arco VRZ shows flat lyin

S. M. Jackson; G. S. Carpenter; R. P. Smith; J. L. Casper

2006-10-01

39

A study of faulting patterns in the Pearl River Mouth Basin through analogue modeling  

NASA Astrophysics Data System (ADS)

The Pearl River Mouth Basin is one of the most favorable areas for gas exploration on the northern slope of the South China Sea. Differences of fault patterns between shelf and slope are obvious. In order to investigate the tectonic evolution, five series of analogue modeling experiments were compared. The aim of this study is to investigate how crustal thickness influences fault structures, and compare this to the observed present-day fault structures in the Pearl River Mouth Basin. The initial lithospheric rheological structure can be derived from the best fit between the modeled and observed faults. The results indicate. (1) Different initial crustal rheological structures can produce different rift structures in the Pearl River Mouth Basin. (2) We also model that the Baiyun Sag in the southern Pearl River Mouth Basin may have had a thinned crust before rifting compared to the rest of the basin. (3) The thickness ratio of brittle to ductile crust in southern Pearl River Mouth Basin is less than normal crust, suggesting an initially hot and weak lithosphere. (4) Slightly south of the divergent boundary magma may have taken part in the rifting process during the active rift stage.

Zhang, Yun Fan; Sun, Zhen

2013-08-01

40

Overview of the Proposed Mississippi Headwaters - Red River Hydrologic Observatory  

NASA Astrophysics Data System (ADS)

A consortium of universities, led by The Ohio State University and the University of North Dakota, in collaboration with The Nature Conservancy - Minnesota and the Dakotas Chapter, are proposing to develop the Mississippi Headwaters - Red River (MHRR) Hydrologic Observatory (HO). The region encompassed by the observatory includes the Red River watershed, the Upper Crow Wing River, the headwaters of the Mississippi River above Leech Lake, the closed Devils Lake basin and the central portion of the Prairie Pothole Region (PPR). The MHRR HO covers about 101,000 km2 and straddles the continental divide. The large size will permit the study of unique science problems and will provide a large contiguous region suitable for coupled large-scale climatic/hydrologic/ecological investigations. Although not part of this proposal, we are also organizing a consortium of primarily Canadian universities interested in carrying out complementary studies on the large Assiniboine basin in Manitoba and Saskatchewan with funding from Canadian sources. The combined study areas will facilitate climate/hydrologic/ecological studies on a broad scale, together with much more focused local scale studies. The research plan focuses on (i) climate variability and future climate change, (ii) wetland dynamics, restoration, and policy considerations associated with global climate change, (iii) carbon, nutrient, and contaminant cycling in complex systems, (iv) assessment and modeling of large, coupled climate/water systems, and (v) new and emerging technologies for near real-time monitoring and assessment. The science themes focus explicitly on exploring the interfaces among traditional science disciplines (hydrology, ecology, climatology) and implicitly on the atmosphere/land surface/subsurface interfaces that are part of the hydrologic cycle. The location of the MHRR HO was purposely selected as one of the most promising areas to pursue these science and technology themes. The region is distinguished by broad climate variability, which has been manifested by extreme swings from drought to deluge. Lake and river systems are considered to be extremely vulnerable to effects related to global climate change. This HO is a place where wetlands and small lakes still remain as an important component of hydrologic/ecological settings and have important implications for carbon sequestration, greenhouse gas production, and recycling of water between terrestrial and atmospheric systems.

Schwartz, F. W.; Gerla, P. J.; Kucera, P. A.

2004-12-01

41

The Red Sea - New insights from recent geophysical studies and the connection to the Dead Sea fault  

NASA Astrophysics Data System (ADS)

The Red Sea is part of a long system of rifts, which formed as a result of African-Arabian continental breakup during the Oligocene-Miocene. Two phases of volcanism are generally accepted, the first occurring 31 mya and the second ˜25 mya. Sometime between 20 and 14 Ma motion along the Dead Sea fault developed and new plate geometry arose to reflect the collision of Arabia with Eurasia. As a result, extension along the northern Red Sea switched from rift-normal (N60°E) to highly oblique and parallel to the newly formed fault. Sea-floor spreading commenced in the southern Red Sea at about 5 Ma leading to a change in the way extension is accommodated along its length. In general the Red Sea is divided into three segments with distinct morphologies and geophysical characteristics: southern (between 15°N and 20°N) - active seafloor spreading, central transition zone (20-23.3°N) with discontinuous axial trough and isolated cells of seafloor spreading, northern dominated by an axial depression is currently in the late stages of continental rifting. Magnetic and gravity data support the differences between the southern and northern sections, while new tomographic studies indicate that the central section behaves as a separate entity that does not act as a transfer zone that gradually transmits processes from south to north. Rifting in the southern Red Sea is under the influence of the Afar plume, while in the north, new evidence points to a strong connection with the Dead Sea fault (fault-parallel and perpendicular features indicating motion parallel to the fault). Motion along the fault may be the stronger force acting on the northern Red Sea and hence, it will behave differently than the southern section. The northern section may act as an area, which transfers motion from seafloor spreading (central-southern Red Sea) to strike-slip (Dead Sea fault).

Lazar, Michael; Ben-Avraham, Zvi; Garfunkel, Zvi

2012-06-01

42

Basement Surface Faulting and Topography for Savannah River Site and Vicinity  

SciTech Connect

This report integrates the data from more than 60 basement borings and over 100 miles of seismic reflection profiling acquired on the Savannah River Site to map the topography of the basement (unweathered rock) surface and faulting recorded on this surface.

Cumbest, R.J.

1998-12-17

43

The significance of geological and zircon age data derived from the wall rocks of the Ailao Shan–Red River Shear Zone, NW Vietnam  

NASA Astrophysics Data System (ADS)

This paper offers new evidence on whether the Ailao Shan–Red River Shear Zone of NW Vietnam is part of a suture zone between two continental blocks (the IndoChina Block and the South China Block) or whether it is itself of intracontinental origin, developed within the South China margin. To help clarify the role that the Ailao Shan–Red River Shear Zone plays in South China tectonic reconstructions, we gathered new whole-rock geochemistry, structural field data, and zircon U–Pb (SHRIMP) ages from granites, rhyodacites, and migmatites that occur within geological units adjacent to both the SW and NE sides of the Red River Fault Zone, a segment of the larger shear zone. The new zircon ages show that both walls of the Red River Fault Zone contain metamorphic and intraplate A-type granitoid rocks of Late Permian–Early Triassic age (263–240 Ma) and are of Indosinian origin. In the SW wall, the Fan Si Pan complex is a Neoproterozoic basement of metagranites and metasediments that was intruded by Late Permian (˜260 Ma), peralkaline, A-type granites and by subalkaline, A-type, biotite granite of Eocene age (˜35 Ma), containing xenoliths of gneissified Permian granitoids. The two intrusive episodes were separated by regional tectonic deformations occurring within a transpressional regime of a NW/W-vergent thrusting with a left-lateral oblique component, that was associated with greenschist to amphibolite facies metamorphism, presumably also of Eocene age (˜50–35 Ma), and that may have been related to the left-lateral movement on the Ailao Shan–Red River Shear Zone. In the NE wall, the Lo Gam complex is a Neoproterozoic basement (˜767 Ma) that was repeatedly subjected to tectonothermal activity throughout the Palaeozoic (at ˜450–420 Ma, ˜350 Ma, ˜265 Ma), ending in the Early Triassic (˜248 Ma). There was no thermal overprint during the Cenozoic. In this wall, a significant part of the Permo-Triassic thermotectonism was ductile shearing that was concentrated along dextral, strike-slip NW-trending zones in the vicinity the Ailao Shan–Red River Shear Zone but that became a type of NE/N-ward extensional/contractional, regional movement further away of it. An early shearing on the Ailao Shan–Red River Shear Zone may date back to the Permo-Triassic and we consider that this probably originated in a continental fault zone initiated in the hinterland of the oblique Indosinian collisional zone.

?ela?niewicz, Andrzej; Hòa, Tr?n Tr?ng; Larionov, Alexander N.

2013-09-01

44

Streamflow losses along the Balcones Fault Zone, Nueces River basin, Texas  

USGS Publications Warehouse

An investigation was conducted to quantify and to determine distribution of streamflow losses and gains that occur during base flow conditions in the Balcones Fault Zone of the Neuces River basin. The streams studied include the West Nueces, Nueces , Dry Frio, Frio, and Sabinal Rivers, and Seco, Hondo, and Verde Creeks. Discharge measurements made during storm recession flows of these streams identified direct recharge to outcrops of the Edwards aquifer and related limestones that ranged from as high as 393 cubic feet per second for the Frio River to as low as 42 cubic feet per second for the Sabinal River. Recharge to outcrops of the Buda Limestone, Eagle Ford Shale, and Austin Group also eventually reaches the Edwards aquifer, and measurements identified losses to these formations ranging from as high as 174 cubic feet per second for the Frio River to near zero for Verde Creek. (USGS)

Land, L. F.; Boning, C. W.; Harmsen, Lynn; Reeves, R. D.

1983-01-01

45

Acoustical facies analysis at the Ba Lat delta front (Red River Delta, North Vietnam)  

NASA Astrophysics Data System (ADS)

A shallow penetrating, high-resolution acoustic study was performed in the Ba Lat delta, the major distributary of the Red River System in Northern Vietnam. An acoustic facies map was constructed and the various facies types were validated through analysis of bottom sediments, by a study of gravity cores collected at 22 stations. Analysis of the acoustic profiles and gravity cores revealed the presence of an asymmetrical, S to SW prograding prodelta lobe, in accordance with the prevailing longshore currents to the S. The southern part of this prodelta is detached from the protruding Ba Lat delta front. The prodelta is dominated by muddy sediments with minor thin (<5 cm) sandy and silty layers. The coarser-grained layers decrease in abundance away from the Ba Lat river mouth. Offshore, the modern delta deposits are characterized by an off-lapping contact over a semi-prolonged bottom reflector lacking any sub-bottom reflectors. This semi-prolonged bottom reflector is correlated with sandy deposits of presumably Early Holocene age. Bottom and coastal erosion is restricted to two areas N and SW of the Ba Lat. Erosion in the North is inferred to be due to reduced sediment supply as a result of shifting in 1971 of the main outlet to its present, more southern location. The erosional area along the Hai Hau coast SW of the Ba Lat also has experienced a reduction in sediment supply in the course of the 20th century, when the local Song Vop distributary channel became less active and was completely dammed in the 1970s. Most sediment supplied by the Ba Lat at present bypasses the Hai Hau erosional coastal zone, as the active part of the Ba Lat prodelta is detached from the coast SW of the Ba Lat. An active, NNE-SSW trending fault system with surface expression is located along the offshore edge of the prodelta, and is linked to deeper fault structures in this active neotectonic region. Subsurface reflectors are folded in the vicinity of the fault.

van den Bergh, G. D.; van Weering, Tj. C. E.; Boels, J. F.; Duc, D. M.; Nhuan, M. T.

2007-02-01

46

Red River Stream Improvement Final Design Nez Perce National Forest.  

SciTech Connect

This report details the final stream improvement design along the reach of Red River between the bridge below Dawson Creek, upstream for approximately 2 miles, Idaho County, Idaho. Geomorphic mapping, hydrologic profiles and cross-sections were presented along with existing fish habitat maps in the conceptual design report. This information is used to develop a stream improvement design intended to improve aquatic habitat and restore riparian health in the reach. The area was placer mined using large bucket dredges between 1938 and 1957. This activity removed most of the riparian vegetation in the stream corridor and obliterated the channel bed and banks. The reach was also cut-off from most valley margin tributaries. In the 50 years since large-scale dredging ceased, the channel has been re-established and parts of the riparian zone have grown in. However, the recruitment of large woody debris to the stream has been extremely low and overhead cover is poor. Pool habitat makes up more than 37% of the reach, and habitat diversity is much better than the project reach on Crooked River. There is little large woody debris in the stream to provide cover for spawning and juvenile rearing, because the majority of the woody debris does not span a significant part of the channel, but is mainly on the side slopes of the stream. Most of the riparian zone has very little soil or subsoil left after the mining and so now consists primarily of unconsolidated cobble tailings or heavily compacted gravel tailings. Knapweed and lodgepole pine are the most successful colonizers of these post mining landforms. Tributary fans which add complexity to many other streams in the region, have been isolated from the main reach due to placer mining and road building.

Watershed Consulting, LLC

2007-03-15

47

Tectonic evolution of the Priest River complex, northern Idaho and Washington: A reappraisal of the Newport fault with new insights on metamorphic core complex formation  

Microsoft Academic Search

New geologic mapping, 40Ar\\/39Ar thermochronometry, and geobarometry in the Middle Eocene Priest River metamorphic core complex provide the basis for unraveling the role of en echelon fault systems in core complex formation and for determining the scale of crustal fragments that form during continental extension. Four faults occur in the Priest River complex. The east verging Purcell Trench fault zone

P. Ted Doughty; Raymond A. Price

1999-01-01

48

Rheological control on the initial geometry of the Raft River detachment fault and shear zone, western United States  

Microsoft Academic Search

The strain, exhumation history, and field orientation of a well-exposed shear zone and detachment fault in the Raft River Mountains of northwestern Utah, a Cordilleran metamorphic core complex, have been studied to determine the kinematics of ductile shearing and initial orientations of the shear zone and detachment fault. Mapping and strain and kinematic analysis indicate that the top-to-the-east Raft River

Michael L. Wells

2001-01-01

49

Fan-delta and interdeltaic shoreline sediments of Middle Devonian Granite Wash and Keg River clastics, Red Earth field, north Alberta basin, Canada  

SciTech Connect

A detailed sedimentological investigation of over 4000 ft of core and 500 well logs of the Middle Devonian granite wash and Keg River clastics in the Red Earth field, North Alberta basin, Canada, has led to the recognition of a granite wash subaerial fan-delta system that is laterally continuous with a Keg River subaqueous delta component along an eastern shoreline of the ancestral Peace River arch. The subaerial fan delta includes alluvial fan facies, sheet wash and mud flows, and playa lakes. The subaqueous delta component includes lower shoreface, upper shoreface, beach-foreshore, eolian sand dunes, lagoon, washover sands, tidal channels and flats, and supratidal carbonates and anhydrites. Within this system, six mappable units are defined. A conceptual depositional model for the sequence depicts four main events. (1) Erosion of Peach River arch uplifted fault blocks, which produced coarse-grained fan-delta sediments in an adjacent fault-bounded margin. Subsequent fluvial reworking resulted in the deposition of thick, lenticular, wedge-shaped alluvial fans of granite wash. (2) Progradation of alluvial fans seaward into the Keg River Sea. (3) Transgression by Middle Devonian seas from the east, which reworked alluvial fans and led to deposition of discontinuous linear sand bodies represented by the Keg River regressive shoreline sediments. (4) Restriction of the sea by the Presqu'ile barrier reef to the north, which deposited evaporites of the Muskeg Formation over the whole sequence. Modern analog to this fan-delta system is the coastal fans of the Gulf of Aqaba, Red Sea. Red Earth field contains over 27 million bbl of recoverable oil, related to a combination structural-stratigraphic trap.

Sabry, H.

1989-03-01

50

Deep seated landslides along the Meilungshan fault in Laonung River Waterdhed, southern Taiwan  

NASA Astrophysics Data System (ADS)

Landslides in Taiwan represent one of most relevant natural hazards for the society. In particular, the large scaled deep-seated landslides deserve attention, because they can be reactivated during intense events and can evolve into destructive failures. For example, one deep seated landslide, the Hsiaolin landslide, with an area of about 250 ha, buried the entire village of Hsiaolin in Kaohsiung County causing 397 causalities, the disappearance of 53 others, and buried over 100 houses during the Typhoon Morakot in 2009. The Laonung River watershed which covered 1367 km2 is selected as our study area. The study area is mainly compose of Miocene slate and sedimentary rocks that are separated by a major fault, the Meilungshan fault. The Meilungshan fault is part of the boundary fault separating the Central Range and Western Foothill in southern Taiwan. The fault is a west verging, high angle NNE trending thrust. Some outcrops show the fault zone is over one hundred and fifty meters thick, and it is mainly composed of gouge and fault breccias of slate. Within the study area, 361 sites with an area greater than 10 ha and with sliding topographic features of deep seated landslide such as crown main escarpment, down slope scarp, up slope scarps, and lateral cracks are recognized from LiDAR derived 1 m resolution DEM. Among these, 16 sites are selected for field investigation and all of them are confirmed as deep seated landslides. This implies the reliability of interpretation results from LiDAR derived DEM even in heavy forest region such as Taiwan. In order to know the influence of the Meilungshan fault in the development of deep seated landslides, landslide density are calculated. The landslide density is 7.7% when whole watershed is considered. However, the landslide density significantly increases to 19.3% when only an area 223km2 that contains the Meilungshan fault with a 2km buffer zone is in the calculation. This result indicates that deformation zone associated with major fault is crucial in the development of deep seated landslides in the study area.

Ho, Dia-Jie; Lin, Ching-Weei; Tseng, Chih-Ming

2013-04-01

51

The changing flow regime and sediment load of the Red River, Viet Nam  

NASA Astrophysics Data System (ADS)

South-East Asian Rivers contribute very significantly to the global sediment load to the ocean, hence to global biogeochemical cycles, and are subject to rapid changes owing to recent population and economic growth. The Red River system (Viet Nam and China) offers a good example of these changes. Previous estimates (before the year 1980) of the suspended matter loading of the Red River ranged from 100 to 170 × 106 t yr-1, i.e. from 640 to 1060 t km-2 yr-1. The strong dependence of suspended solid transport on hydrology results in a large year-to-year variability. Based on the available hydrological data from the period 1997 2004, and on a one-year survey of daily suspended matter of the three main tributaries of the Red River system in 2003, a simplified modeling approach, distinguishing between surface runoff and base flow, is established to estimate the mean suspended loading of the Red River under present conditions. The obtained value is 40 × 106 t yr-1, corresponding to a specific load of 280 t km-2 yr-1. It reflects a 70% decrease of the total suspended load since the impoundment of the Hoa Binh and Thac Ba reservoirs in the 1980s. Following the planned construction of two additional reservoirs, the model predicts a further reduction by 20% of the suspended load of the Red River, which might be compensated by an expected increase in suspended loading due to enhanced rainfall induced by climate change. Using measurements of the total phosphorus content of the suspended material in the different Red River tributaries, the present phosphorus delivery by the Red River can be estimated as 36 × 106 kgP yr-1.

Le, Thi Phuong Quynh; Garnier, Josette; Gilles, Billen; Sylvain, Théry; van Minh, Chau

2007-02-01

52

Establishment of a viable population of red-cockaded woodpeckers at the Savannah River Site  

Microsoft Academic Search

In 1985 the Southeastern Forest Experiment Station in cooperation with the Department of Energy (DOE), the Savannah River Forest Station (SRFS) and the Savannah River Ecology Laboratory (SREL) initiated a research\\/management program to restore a viable population of red-cockaded woodpeckers (RCW) to the Savannah River Site (SRS). The program has progresses in two phases. The first phase (1985-1987) focused on

1989-01-01

53

High resolution seismic survey, Pen Branch Fault, Savannah River Site, South Carolina  

SciTech Connect

An investigation of the Pen Branch Fault at the Savannah River Site by a series of short, high resolution seismic reflection lines was conducted. The purpose was to acquire, process, and interpret 19.9 miles of data, optimized for the upper 300 ft of geologic strata, in sufficient density such that processing performed in the conventional stepwise approach, followed by detailed interpretation, would define small scale spatial variability and structural features in the vicinity of the fault leading to definition of the location of the fault, the shallowest extent of the fault, and the quantification of the sense and magnitude of motion. The depth of optimization for the last two lines was modified to the 300 ft of geologic strata immediately above basement. Three older seismic surveys, other geophysical data, and associated borehole and geologic data were reviewed. The equipment and the acquisition, processing, and interpretation procedures are discussed in the report. The report includes a detailed line by line description and discussion of the interpretation. Figures include reference maps, contour displays of the stacking and interval velocities, diagrammatic references sketches of the interpreted layering and sedimentary features, index sketches, and specific color prints made on the workstation during the course of the interpretation. A volume of manuals on seismic devices and related equipment is included.

Berkman, E. (Emerald Exploration Consultants, Inc., Austin, TX (United States))

1991-04-01

54

High resolution seismic survey, Pen Branch Fault, Savannah River Site, South Carolina. Final report  

SciTech Connect

An investigation of the Pen Branch Fault at the Savannah River Site by a series of short, high resolution seismic reflection lines was conducted. The purpose was to acquire, process, and interpret 19.9 miles of data, optimized for the upper 300 ft of geologic strata, in sufficient density such that processing performed in the conventional stepwise approach, followed by detailed interpretation, would define small scale spatial variability and structural features in the vicinity of the fault leading to definition of the location of the fault, the shallowest extent of the fault, and the quantification of the sense and magnitude of motion. The depth of optimization for the last two lines was modified to the 300 ft of geologic strata immediately above basement. Three older seismic surveys, other geophysical data, and associated borehole and geologic data were reviewed. The equipment and the acquisition, processing, and interpretation procedures are discussed in the report. The report includes a detailed line by line description and discussion of the interpretation. Figures include reference maps, contour displays of the stacking and interval velocities, diagrammatic references sketches of the interpreted layering and sedimentary features, index sketches, and specific color prints made on the workstation during the course of the interpretation. A volume of manuals on seismic devices and related equipment is included.

Berkman, E. [Emerald Exploration Consultants, Inc., Austin, TX (United States)

1991-04-01

55

Habitat preferences of foraging red-cockaded woodpeckers at the Savannah River Site, South Carolina.  

SciTech Connect

Franzreb, Kathleen, E. 2004. Habitat preferences of foraging red-cockaded woodpeckers at the Savannah River Site, South Carolina. In: Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 9. Habitat Management and Habitat Relationships. Pp 553-561. Abstract: I constructed a foraging study to examine habitat use of red-cockaded woodpeckers at the Savannah River Site, South Carolina. Because much of the land had been harvested in the late 1940s and early 1950s prior to being sold to the Department of Energy, the available habitat largely consisted of younger trees (e.g., less than 40 years old). From 1992 to 1995, I examined the foraging behavior and reproductive success of 7 groups of red-cockaded woodpeckers.

Franzreb, Kathleen, E.

2004-12-31

56

Red shiner invasion and hybridization with blacktail shiner in the upper Coosa River, USA  

Microsoft Academic Search

Human disturbance increases the invasibility of lotic ecosystems and the likelihood of hybridization between invasive and\\u000a native species. We investigated whether disturbance contributed to the invasion of red shiner (Cyprinella lutrensis) and their hybridization with native blacktail shiner (C. venusta stigmatura) in the Upper Coosa River System (UCRS). Historical records indicated that red shiners and hybrids rapidly dispersed in the\\u000a UCRS

David M. Walters; Mike J. Blum; Brenda Rashleigh; Byron J. Freeman; Brady A. Porter; Noel M. Burkhead

2008-01-01

57

The role of phytochemistry in dietary choices of Tana River red colobus monkeys (Procolobus badius rufomitratus)  

Microsoft Academic Search

We conducted a phytochemical survey of tree species growing within the riverine forests of the Tana River National Primate\\u000a Reserve in Kenya to understand better the feeding ecology of an endangered resident primate, the Tana River red colobus monkey (Procolobus badius rufomitratus).Young leaves, which make up a large percentage of this monkey's diet, are significantly higher in nitrogen and lower

Christopher B. Mowry; Barbara S. Decker; Donald J. Shure

1996-01-01

58

Evolution of the K?z?l?rmak river and its interaction with the North Anatolian Fault, Turkey  

NASA Astrophysics Data System (ADS)

The North Anatolian Fault (NAF) is a 1500km long dextral strike-slip fault, which accommodates the extrusion of the Anatolian Plate away from the Arabia/Eurasia collision zone at a rate of 20-25mm/yr. The fault strongly affects the whole drainage network and, especially, the K?z?l?rmak River. The K?z?l?rmak River is the longest river in Turkey (1350km); it formed during the Pliocene and rose in eastern Anatolia. The river drains a part of the Anatolian Plateau, crosses the North Anatolian Fault and the Pontides mountains before reaching the Black Sea. Whereas wide terraces are preserved along the K?z?l?rmak River in the Anatolian Plateau, where a recent study (Dogan 2009) determines an incision rate of 0.08 mm/yr according to 40Ar/39Ar datations on basalts, no clear terraces can be mapped further North where the river incises through the Pontides Mountains. Our study focuses on the central part of the fault affected by the 280 km long 1943 Tosya earthquake rupture. In this area the NAF makes a wide convex arc about 100km south to the Black Sea coast, and offset by 30 km the K?z?l?rmak River. Indeed, south of the NAF the K?z?l?rmak River flows to North/East. Then it is deviated along the NAF in the Karg? pull-apart and flows to the East parallel to the fault for 30km before bending again to the North/East in the Kamil pull-apart. Around the two bends of the River three alluvial terraces can be mapped. The lowest one (10m high above the present river level) is preserved in the Karg? pull-apart. The two other ones (60 and 100m above the K?z?l?rmak River) are situated further east in the Kamil pull-apart. The highest terrace is offset by at least 300m offset along the NAF. The ages of sampled terraces are constrained using 10Be and 36Cl cosmogenic dating methods. The in situ cosmogenic 36Cl exposure ages calculated apply from 22ka for the lowest terrace, to 100 ka for the highest terrace in the erosion preserved area. The highest terrace shows a contribution of younger ages (the same time interval of 50ka of the intermediate terrace) certainly coming from the catchement just above. The proximity of ages may be due to the short time-interval between the both highest terraces incision by the K?z?l?rmak river. 10Be measurements on sand coming from river beds will provide past to actual erosion rates along the K?z?l?rmak River as well as present erosion rate from small rivers flowing to the river. The goals of this study are to constrain, 1/ the origin of the terraces (climatic or tectonic), 2/ the slip rate of the NAF integrated over more than 20 000 years, 3/ the evolution of the K?z?l?rmak River incision rate, 4/ the influence of the vertical motion in the NAF convex arc region on the present incision rate of small rivers flowing toward the K?z?l?rmak.

Drab, L.; Hubert Ferrari, A.; Benedetti, L.; van der Woerd, J.

2010-12-01

59

A climatology of airborne dust for the Red River Valley of North Dakota  

Microsoft Academic Search

The Red River Valley of North Dakota has been identified as one of the highest potential dust production regions in the United States. This paper provides a climatological summary of the airborne dust environment in the region using historical meteorological data for Fargo, North Dakota. Data for the period 1948–1994 were extracted for all 3-hourly weather observations which recorded an

Nancy A Godon; Paul E Todhunter

1998-01-01

60

Graffiti on the great plains: A social reaction to the Red River Valley flood of 1997  

Microsoft Academic Search

Superficially, graffiti and disasters seem unrelated. Nevertheless, following the Red River Valley flood of 1997, a private form of graffiti emerged in public spaces in the twin cities of Grand Forks, North Dakota and East Grand Forks, Minnesota. Five thematic categories of graffiti emerged through the analysis of photographed images. The emergence and content of the graffiti appear to be

Clifford O. Hagen

1999-01-01

61

Fish Discoveries by the Lewis and Clark and Red River Expeditions  

Microsoft Academic Search

The Lewis and Clark Expedition of 1804–1806 and the Red River Expedition of 1806 were two early explorations of the land acquired by the United States in the Louisiana Purchase in western North America. They were the first such western excursions to include natural history investigations as part of the trip objectives—a reflection of Thomas Jefferson's strong scientific curiosity. Whereas

John R. Moring

1996-01-01

62

Community-based Disaster Management During the 1997 Red River Flood in Canada  

Microsoft Academic Search

This paper examines the relationship between community preparedness and response to natural disaster and their level and pattern of community development. This is done by investigating preparation and response to the 1997 Red River Flood by three rural communities in Manitoba, Canada. The communities were selected because of their different ethnic mix and associated level and pattern of community development.

Jerry Buckland; Matiur Rahman

1999-01-01

63

Red River Valley Tornadoes of April 10, 1979, A Report to the Administrator.  

National Technical Information Service (NTIS)

The three main storms in the Red River Valley outbreak were giant tornadoes. Each lasted for an hour or more and left a continuous track of ground damage 35 miles or longer. In addition, the damage path of all three was wider than normal. A NOAA disaster ...

1980-01-01

64

Metal accumulation in eggs of the red-eared slider ( Trachemys scripta elegans) in the Lower Illinois River  

Microsoft Academic Search

The Illinois River is a highly utilized navigable waterway in the US Midwest, and has historically been contaminated with metal toxicants from various industrial and municipal pollution sources. Little information on metal contamination is available in the Lower Illinois River, and in particular, in the habitat of the red-eared slider (Trachemys scripta elegans) at the southern end of the river

Anna E. Tryfonas; John K. Tucker; Paul E. Brunkow; Kevin A. Johnson; Hussein S. Hussein; Zhi-Qing Lin

2006-01-01

65

Larval Fish as Indicators of Reproductive Success in Unchannelized and Channelized Tributaries of the Red River Basin, Minnesota  

Microsoft Academic Search

During 1998 and 1999, larval fish phenology, abundance, and diversity were characterized at 13 reaches in the Buffalo River and Sand Hill River, tributaries of the Red River of the North. Channelized reaches were less stable than unchannelized reaches, showing more overall variation and greater daily fluctuation in temperature and dissolved oxygen (DO), and a higher level of intermittent flow.

Maija L. Meneks; Bruce Vondracek; Jay Hatch

2003-01-01

66

Establishment of a viable population of red-cockaded woodpeckers at the Savannah River Site. Annual report, FY 1990  

Microsoft Academic Search

In 1985 the Southeastern Forest Experiment Station (SEFES) in cooperation with the Department of Energy, the Savannah River Forest Station (SRFS) and the Savannah River Ecology Laboratory (SREL) initiated a research\\/management program to restore a viable population of red-cockaded woodpeckers (RCW) to the Savannah River Site (SRS). We managed to stabilize the population in the first couple of years through

1990-01-01

67

Repeated Historic Surface Ruptures of the Denali Fault at Delta River, Alaska During Large Earthquakes in 1912 and 2002  

NASA Astrophysics Data System (ADS)

The Denali fault ruptured through stands of mature spruce trees on the Delta River valley floor during an Ms 7.2-7.4 earthquake on July 6, 1912 and again during the Mw 7.9 earthquake of November 3, 2002. In both events, most trees on the surface rupture along 2 km of the fault trace were damaged by splitting and tilting. Displacements in both events were dextral with a subordinate dip-slip component (south side down). Tree ring counts from older damaged trees on the fault trace closely date the age of the penultimate event at 1912. The only earthquake that fits the requirements for timing, location, and size to have caused the pre-2002 tree damage is an Ms 7.2-7.4 event on July 6, 1912, the epicenter of which had been located 40 km southwest of the Delta River fault crossing by Boyd and Lerner-Lam (1988). Intensity data for the widely felt 1912 earthquake are compatible with unilateral westward rupture on the Denali Fault. Empirical data for the estimated magnitude range of the 1912 earthquake suggest a surface rupture length of 60-84 km, average horizontal displacement of 140-210 cm, and maximum horizontal displacement of 240-390 cm (Wells and Coppersmith, 1994). The 2002 surface rupture was marked by large dextral surface slip (to 800+ cm) and variable dip slip along 240 km of the Denali Fault and 65 km of the Totschunda fault in the central Alaska Range. The Delta River valley, 90 km east of the 2002 epicenter, lies within a transition zone about 10 km wide in which dextral slip diminishes from 600 cm or more east of the valley to less than 450 cm west of the valley. Geodetic data for the 2002 rupture along the TAPS oil pipeline in the Delta River valley indicate a total of 580 cm dextral slip and 130 cm dip slip distributed over a zone 1,000 m wide. Surface trace of the fault is poorly developed on the valley floor because of distributive deformation in the thick underlying unconsolidated deposits; offsets on individual fissures are less than 130 cm dextral and 60 cm vertical. Paleoseismologic data from test pits at the west bank of the Delta River indicate two earlier surface faulting events on the Denali Fault probably comparable in size to the 2002 earthquake. Preliminary 14C dates of these paleo-events suggest a recurrence interval of about 350-400 years and an average long term slip rate of about 15 mm/yr. Rupture during the smaller 1912 earthquake contributes to reduce the size of any 2002 slip deficit that may exist along the Denali fault in the Delta River valley and probably also in the low-slip segment extending 70 km west of the valley to the end of the 2002 Denali fault surface trace.

Plafker, G.; Carver, G.; Metz, M.; Cluff, L.

2004-12-01

68

Red shiner invasion and hybridization with blacktail shiner in the upper Coosa River, USA  

USGS Publications Warehouse

Human disturbance increases the invasibility of lotic ecosystems and the likelihood of hybridization between invasive and native species. We investigated whether disturbance contributed to the invasion of red shiner (Cyprinella lutrensis) and their hybridization with native blacktail shiner (C. venusta stigmatura) in the Upper Coosa River System (UCRS). Historical records indicated that red shiners and hybrids rapidly dispersed in the UCRS via large, mainstem rivers since the mid to late 1990s. We measured the occurrence and abundance of parental species and hybrids near tributary-mainstem confluences and characterized populations at these incipient contact zones by examining variation across morphological traits and molecular markers. Red shiners represented only 1.2% of total catch in tributaries yet introgression was widespread with hybrids accounting for 34% of total catch. Occurrence of red shiners and hybrids was highly correlated with occurrence of blacktail shiners, indicating that streams with native populations are preferentially colonized early in the invasion and that hybridization is a key process in the establishment of red shiners and their genome in new habitats. Tributary invasion was driven by post-F1 hybrids with proportionately greater genomic contributions from blacktail shiner. Occurrence of red shiners and hybrids and the relative abundance of hybrids significantly increased with measures of human disturbance including turbidity, catchment agricultural land use, and low dissolved oxygen concentration. Red shiners are a significant threat to Southeast Cyprinella diversity, given that 41% of these species hybridize with red shiner, that five southeastern drainages are invaded, and that these drainages are increasingly disturbed by urbanization. ?? 2007 Springer Science+Business Media B.V.

Walters, D. M.; Blum, M. J.; Rashleigh, B.; Freeman, B. J.; Porter, B. A.; Burkhead, N. M.

2008-01-01

69

South Fork Clearwater River Habitat Enhancement, Crooked and Red Rivers : Annual Report, 1989  

Microsoft Academic Search

In 1983, the Nez Perce National Forest and the Bonneville Power Administration entered into an interagency agreement to enhance and improve habitat for two anadromous fish species, spring chinook salmon (Oncorhynchus tshawyscha) and summer steelhead trout (Onchorhyncus mykiss), in the South Fork Clearwater River tributaries. The South Fork Clearwater River was dammed in 1927 for hydroelectric development. Anadromous fish runs

Baer; William H

1990-01-01

70

Rheological control on the initial geometry of the Raft River detachment fault and shear zone, western United States  

NASA Astrophysics Data System (ADS)

The strain, exhumation history, and field orientation of a well-exposed shear zone and detachment fault in the Raft River Mountains of northwestern Utah, a Cordilleran metamorphic core complex, have been studied to determine the kinematics of ductile shearing and initial orientations of the shear zone and detachment fault. Mapping and strain and kinematic analysis indicate that the top-to-the-east Raft River shear zone initially developed parallel to an unconformity separating Archean rocks from overlying Proterozoic quartzite and schist for at least 24 km in the shear direction. Experimental rock deformation data from lithologies similar to the Archean and Proterozoic rocks suggest the unconformity represented a significant rheological boundary at the deformation temperatures; the base of the shear zone was localized along the boundary between relatively weak quartzite above and stronger monzogranite below. An extensive thermochronological database is used to reconstruct the position of the basement unconformity in temperature-lateral distance coordinates. The initial average dip of the shear zone and basement unconformity is estimated between 7° and 30°, assuming subhorizontal isotherms and geothermal gradients of 20°-40°C/km. The east dip of the unconformity at the onset of Miocene extension is interpreted to have resulted from late Eocene unroofing and flexure beneath a top-to-the-WNW extensional shear zone in the western Raft River, Grouse Creek, and Albion Mountains. The observations from the Raft River shear zone suggest that the orientation of some midcrustal shear zones may not reflect the predicted orientation for ductile faults according to ductile failure criteria but, rather, the orientation of rheological boundaries along which deformation is localized. Furthermore, detachment faults that are superimposed on mylonite during progressive displacement and footwall unroofing may use an inherited mechanical anisotropy from the mylonite, and their orientations may not reflect the predicted orientation of shear fractures in isotropic rock. The common parallelism between detachment faults and mylonitic foliation may indicate a mechanical and kinematic preference for localization of throughgoing brittle faults parallel to preexisting mylonitic foliation. Because of this preference, studies restricted to detachment faults which lack footwall mylonite or restricted to structural levels between the breakaway and mylonitic front have more bearing on the question of the initial dip of normal-sense shear fractures (faults) within the seismogenic crust.

Wells, Michael L.

2001-08-01

71

Effects of Late Cretaceous and Cenozoic faulting on the geology and hydrology of the coastal plain near the Savannah River, Georgia and South Carolina  

USGS Publications Warehouse

Geologic and hydrologic investigations by the U.S. Geological Survey have defined stratigraphic and hydraulic anomalies suggestive of faulting within Coastal Plain sediments between the Ogeechee River in east-central Georgia and the Edisto River in west-central South Carolina. Examination of borehole cuttings, cores, and geophysical logs from test wells indicate that Triassic rocks and Upper Cretaceous and lower Tertiary Coastal Plain sediments near the Barnwell-Allendale County line near Millett, South Carolina, are offset by a northeast-trending fault downthrown to the northwest. The location of this suspected Coastal Plain fault generally coincides with the location of an inferred fault in basement rocks as interpreted from aeromagnetic surveys. Apparent vertical offsets range from about 700 feet at the base of Upper Cretaceous sediments to about 20 feet in strata of Late Eocene age. As a result, the Upper Cretaceous Middendorf Formation which directly overlies crystalline and Triassic rocks updip (northwest) of this fault, is absent immediately downdip of the fault. The thickness of Tipper Cretaceous sediments is also sharply reduced from about 700 feet to about 180 feet across the fault. Sediments of the basal Coastal Plain aquifer are largely truncated by uplifted Triassic rocks at the fault near Millett, South Carolina. Lateral ground-water flow near the Savannah River Is consequently disrupted updip of the fault and ground water is transferred vertically into overlying sediments and possibly into the Savannah River. At several locations, abrupt changes in potentiometric head occur across this fault. Computed transmissivity of the basal Coastal Plain aquifer is also radically reduced downdip of the fault, sharply reversing a downdip trend of rapidly increasing aquifer transmissivity. Other anomalous potentiometric data along a northeast-trending line between Statesboro, Georgia, and Fairfax, South Carolina, suggest the possibility of similar faulting in correlative geologic units. The location of the suspected fault near Statesboro, Georgia, generally coincides with the eastward extension of the Gulf Trough, a regional potentiometric anomaly in central Georgia.

Faye, R. E.; Prowell, D. C.

1982-01-01

72

Brittle extension of the continental crust along a rooted system of low-angle normal faults: Colorado River extensional corridor  

NASA Astrophysics Data System (ADS)

A transect across the 100 km wide Colorado River extensional corridor of mid-Tertiary age shows that the upper 10 to 15 km of crystalline crust extended along an imbricate system of brittle low-angle normal faults. The faults cut gently down a section in the NE-direction of tectonic transport from a headwall breakaway in the Old Woman Mountains, California. Successively higher allochthons above a basal detachment fault are futher displaced from the headwall, some as much as tens of kilometers. Allochthonous blocks are tilted toward the headwall as evidenced by the dip of the cappoing Tertiary strata and originally horizontal Proterozoic diabase sheets. On the down-dip side of the corridor in Arizona, the faults root under the unbroken Hualapai Mountains and the Colorado Plateau. Slip on faults at all exposed levels of the crust was unidirectional. Brittle thinning above these faults affected the entire upper crust, and wholly removed it locally along the central corridor or core complex region. Isostatic uplift exposed metamorphic core complexes in the domed footwall. These data support a model that the crust in California moved out from under Arizona along an asymmetric, rooted normal-slip shear system. Ductile deformation must have accompanied mid-Tertiary crustal extension at deeper structural levels in Arizona.

John, B. E.; Howard, K. A.

73

Bathymetry of the Hong and Luoc River Junction, Red River Delta, Vietnam, 2010  

USGS Publications Warehouse

The U.S. Geological Survey, in collaboration with the Water Resources University in Hanoi, Vietnam, conducted a bathymetric survey of the junction of the Hong and Luoc Rivers. The survey was done to characterize the channel morphology of this delta distributary network and provide input for hydrodynamic and sediment transport models. The survey was carried out in December 2010 using a boat-mounted multibeam echo sounder integrated with a global positioning system. A bathymetric map of the Hong and Luoc River junction was produced which was referenced to the datum of the Trieu Duong tide gage on the Luoc River.

Kinzel, Paul J.; Nelson, Jonathan M.; Toan, Duong Duc; Thanh, Mung Dinh; Shimizu, Yasuyuki

2012-01-01

74

Surface rupture on the Denali Fault interpreted from tree damage during the 1912 Delta river Mw 7.2-7.4 earthquake: Implications for the 2002 Denali Fault earthquake slip distribution  

USGS Publications Warehouse

During the 3 November 2002 Denali fault earthquake, surface rupture propagated through a small, old-growth forest in the Delta River valley and damaged many trees growing on the fault. Damage was principally the result of fault offset of tree roots and tilting of trees. Some trees were split by surface faults that intersected the base of their trunks or large taproots. A few trees appear to have been damaged by strong shaking. Many of the older trees damaged in 2002 were deformed and scarred. Some of these scarred trees exhibit past damage indicative of surface faulting and have abrupt changes in their annual ring patterns that coincide with the past damage. Annual ring counts from several of these older scarred trees indicate the damage was caused by surface rupture on the Denali fault in 1912. The only earthquake of sufficient magnitude that fits the requirements for timing and general location as recorded by the damaged trees is a widely felt Ms 7.2-7.4 earthquake on 6 July 1912 informally referred to as the 1912 Delta River earthquake. Seismologic data and intensity distribution for the 1912 Delta River earthquake indicate that its epicenter was within 60-90 km of the Delta River and that rupture probably propagated toward the west. Inferred fault length, displacement, and rupture direction suggest the 1912 rupture was probably largely coincident with the western, lower slip section of the 2002 rupture.

Carver, G.; Plafker, G.; Metz, M.; Cluff, L.; Slemmons, B.; Johnson, E.; Roddick, J.; Sorensen, S.

2004-01-01

75

Evolving east Asian river systems reconstructed by trace element and Pb and Nd isotope variations in modern and ancient Red River-Song Hong sediments  

Microsoft Academic Search

Rivers in east Asia have been recognized as having unusual geometries, suggestive of drainage reorganization linked to Tibetan Plateau surface uplift. In this study we applied a series of major and trace element proxies, together with bulk Nd and single K-feldspar grain Pb isotope ion probe isotope analyses, to understand the sediment budget of the modern Red River. We also

Peter D. Clift; Hoang Van Long; Richard Hinton; Robert M. Ellam; Robyn Hannigan; Mai Thanh Tan; Jerzy Blusztajn; Nguyen Anh Duc

2008-01-01

76

Modeling Regional Variation in Riverine Fish Biodiversity in the Arkansas–White–Red River Basin  

Microsoft Academic Search

The patterns of biodiversity in freshwater systems are shaped by biogeography, environmental gradients, and human-induced factors. In this study, we developed empirical models to explain fish species richness in subbasins of the Arkansas–White–Red River basin as a function of discharge, elevation, climate, land cover, water quality, dams, and longitudinal position. We used information-theoretic criteria to compare generalized linear mixed models

Peter E. Schweizer; Henriette I. Jager

2011-01-01

77

INTELLIGENT COMPUTING SYSTEM FOR RESERVOIR ANALYSIS AND RISK ASSESSMENT OF THE RED RIVER FORMATION  

SciTech Connect

Integrated software has been written that comprises the tool kit for the Intelligent Computing System (ICS). The software tools in ICS have been developed for characterization of reservoir properties and evaluation of hydrocarbon potential using a combination of inter-disciplinary data sources such as geophysical, geologic and engineering variables. The ICS tools provide a means for logical and consistent reservoir characterization and oil reserve estimates. The tools can be broadly characterized as (1) clustering tools, (2) neural solvers, (3) multiple-linear regression, (4) entrapment-potential calculator and (5) file utility tools. ICS tools are extremely flexible in their approach and use, and applicable to most geologic settings. The tools are primarily designed to correlate relationships between seismic information and engineering and geologic data obtained from wells, and to convert or translate seismic information into engineering and geologic terms or units. It is also possible to apply ICS in a simple framework that may include reservoir characterization using only engineering, seismic, or geologic data in the analysis. ICS tools were developed and tested using geophysical, geologic and engineering data obtained from an exploitation and development project involving the Red River Formation in Bowman County, North Dakota and Harding County, South Dakota. Data obtained from 3D seismic surveys, and 2D seismic lines encompassing nine prospective field areas were used in the analysis. The geologic setting of the Red River Formation in Bowman and Harding counties is that of a shallow-shelf, carbonate system. Present-day depth of the Red River formation is approximately 8000 to 10,000 ft below ground surface. This report summarizes production results from well demonstration activity, results of reservoir characterization of the Red River Formation at demonstration sites, descriptions of ICS tools and strategies for their application.

Mark A. Sippel; William C. Carrigan; Kenneth D. Luff; Lyn Canter

2003-11-12

78

Life History Characteristics of Red Shiner, Cyprinella lutrensis, in the Lower Platte River, Nebraska, USA  

Microsoft Academic Search

We investigated the life history characteristics of red shiner (Cyprinella lutrensis) from the lower Platte River spring of 2000 to fall of 2003. Most individuals (45.5%) were males, and the overall ratio of males to females was 1:1.74. The largest and heaviest fish were 59.0 mm fork length (FL) and 2.80 g (age 3) for females and 64.6 mm FL

Ayhan Yildirim; Edward J. Peters

2006-01-01

79

A Subsynoptic-Scale Kinetic Energy Study of the Red River Valley Tornado Outbreak (Ave-Sesame 1).  

National Technical Information Service (NTIS)

The subsynoptis-scale kinetic energy balance during the Red River Valley tornado outbreak is presented in order to diagnose storm environment interactions. Area-time averaged energetics indicate that horizontal flux convergence provides the major energy s...

G. J. Jedlovec H. E. Fuelberg

1981-01-01

80

Long-term monitoring (1960–2008) of the river-sediment transport in the Red River Watershed (Vietnam): Temporal variability and dam-reservoir impact  

Microsoft Academic Search

The Red River (China\\/Vietnam, A=155,000km²) is a typical humid tropics river originating from the mountainous area of Yunnan Province in China. Based on information on daily discharge (Q) and suspended particulate matter (SPM) concentration between 1960–2008 for the SonTay gauging station (outlet of the River and entry to the Delta) provided by the National Institute IMHE-MONRE, the mean annual SPM

Thi Ha Dang; Alexandra Coynel; Didier Orange; Gérard Blanc; Henri Etcheber; Lan Anh Le

2010-01-01

81

Problem Soils of the Paddy Fields in the Eastern Coastal Plain of the Red River Delta, Vietnam  

Microsoft Academic Search

Although the Red River Delta is one of the grain cradles in the rice-producing areas of Vietnam, this area contains salt-affected area. In this study, we aim to clarify the distribu- tion and characteristics of problem soils which have led to the land use condition as follows. The salt-affected land in the eastern region of the Red River Delta can

Shigeko HARUYAMA; Hung Thai DINH; Van Tiem LE

82

Establishment of a viable population of red-cockaded woodpeckers at the Savannah River Site  

SciTech Connect

In 1985 the Southeastern Forest Experiment Station in cooperation with the Department of Energy (DOE), the Savannah River Forest Station (SRFS) and the Savannah River Ecology Laboratory (SREL) initiated a research/management program to restore a viable population of red-cockaded woodpeckers (RCW) to the Savannah River Site (SRS). The program has progresses in two phases. The first phase (1985-1987) focused on stabilizing the declining RCW population at SRS. The second phase (1988-present) has focused on facilitating population expansion. In 1989 we have focused our efforts on development of techniques for excavating new RCW cavities, identification of old-growth stands with the potential of providing new nesting habitat to support population expansion, continued flying squirrel control, continued translocations of RCW's as needed, and monitoring clan composition and reproduction.

Allen, D.H.

1989-01-01

83

Evaluating the evolution of the Red River system based on in situ UPb dating and Hf isotope analysis of zircons  

Microsoft Academic Search

The Red River originates from SW China and SE Tibet and has a total length >1000 km. In this study, we present new U-Pb dating and Hf isotopic analysis of zircon grains, from both modern and paleoriver sands in order to constrain the provenance of the modern river and to decipher drainage evolution through time. Our data show that the

Long van Hoang; Fu-Yuan Wu; Peter D. Clift; Anna Wysocka; Anna Swierczewska

2009-01-01

84

Tectonic evolution of the Priest River complex, northern Idaho and Washington: A reappraisal of the Newport fault with new insights on metamorphic core complex formation  

NASA Astrophysics Data System (ADS)

New geologic mapping, 40Ar/39Ar thermochronometry, and geobarometry in the Middle Eocene Priest River metamorphic core complex provide the basis for unraveling the role of en echelon fault systems in core complex formation and for determining the scale of crustal fragments that form during continental extension. Four faults occur in the Priest River complex. The east verging Purcell Trench fault zone on the eastern side consists of two distinct en echelon fault segments separated by an unfaulted homocline. The U-shaped Newport fault system on the northwestern side is a conjugate normal fault set. The west verging eastern Newport fault terminates within the Silver Point Wrencoe pluton, which was intruded syntectonically into the fault zone. The east verging western Newport fault merges with the east verging Spokane dome mylonite zone in the underlying infrastructure. New geobarometric data show that this midcrustal shear zone, which evidently forms part of the regional basal décollement of the Cordilleran fold and thrust belt, also records significant Eocene extensional shearing. Rocks that formed beneath the mylonite zone at a depth of 30-35 km are juxtaposed against rocks that formed at a depth of 10 km above the zone. Eocene 40Ar/39Ar chrontours in the southern part of the infrastructure record progressive exhumation and quenching that becomes younger eastward. In the northern fragment of the infrastructure, alternating domains of progressive westward exhumation/quenching and progressive eastward exhumation/quenching occur beneath the eastern Newport fault and the northern Purcell Trench fault, respectively. These relationships form the basis for a new model of the evolution of the Priest River complex. The southern part of the infrastructure was exhumed by a major east verging detachment system comprising the western Newport fault and the reactivated eastern part of the Spokane dome mylonite zone, into which the western Newport fault merges. This master detachment fault, which roots in the southern Purcell Trench on the east side of the core complex, plunges beneath the northern part of the infrastructure (the Selkirk Crest block). Below the detachment, the infrastructure appears to be intact; above the detachment, the crust extended along a set of relaying conjugate detachment faults. These faults are the eastern Newport fault and the north and south Purcell Trench faults. Kinematic analysis shows that the Selkirk Crest block is a crustal-scale extensional horse that was stranded as continued extension moved the underlying metamorphic infrastructure out from beneath it and toward the west along the master detachment. This study shows that large tracts of midcrustal rocks can be translated and stranded as allochthonous fragments during continental crustal extension.

Doughty, P. Ted; Price, Raymond A.

1999-06-01

85

Evolving east Asian river systems reconstructed by trace element and Pb and Nd isotope variations in modern and ancient Red River-Song Hong sediments  

NASA Astrophysics Data System (ADS)

Rivers in east Asia have been recognized as having unusual geometries, suggestive of drainage reorganization linked to Tibetan Plateau surface uplift. In this study we applied a series of major and trace element proxies, together with bulk Nd and single K-feldspar grain Pb isotope ion probe isotope analyses, to understand the sediment budget of the modern Red River. We also investigate how this may have evolved during the Cenozoic. We show that while most of the modern sediment is generated by physical erosion in the upper reaches in Yunnan there is significant additional flux from the Song Lo, draining Cathaysia and the SW Yangtze Block. Nd isotope data suggest that 40% of the modern delta sediment comes from the Song Lo. Carbonates in the Song Lo basin make this a major control on the Red River Sr budget. Erosion is not a simple function of monsoon precipitation. Active rock uplift is also required to drive strong erosion. Single grain Pb data show a connection in the Eocene between the middle Yangtze and the Red River, and probably with rivers draining the Songpan Garze terrane. However, the isotope data do not support a former connection with the upper Yangtze, Mekong, or Salween rivers. Drainage capture appears to have occurred throughout the Cenozoic, consistent with surface uplift propagating gradually to the southeast. The middle Yangtze was lost from the Red River prior to 24 Ma, while the connection to the Songpan Garze was cut prior to 12 Ma. The Song Lo joined the Red River after 9 Ma. Bulk sample Pb analyses have limited provenance use compared to single grain data, and detailed provenance is only possible with a matrix of different proxies.

Clift, Peter D.; Long, Hoang Van; Hinton, Richard; Ellam, Robert M.; Hannigan, Robyn; Tan, Mai Thanh; Blusztajn, Jerzy; Duc, Nguyen Anh

2008-04-01

86

Nutrient (N, P) budgets for the Red River basin (Vietnam and China)  

NASA Astrophysics Data System (ADS)

In order to examine the degree of human-induced alteration of the nitrogen and phosphorus cycles at the scale of a tropical watershed of regional dimension, the budgets of these two elements were estimated in the four main sub-basins (Da, Lo, Thao, and Delta) of the Red River system (156 448 km2, Vietnam and China). The four sub-basins differ widely in population density (from 101 inhabitants km-2 in the upstream basins to more than 1000 inhabitants km-2 in the delta), land use, and agricultural practices. In terms of agricultural production, on the one hand, and consumption of food and feed on the other, the upstream sub-basins are autotrophic systems, exporting agricultural goods, while the delta is a heterotrophic system, depending on agricultural goods imports. The budget of the agricultural soils reveals great losses of nitrogen, mostly attributable to denitrification in rice paddy fields and of phosphorus, mostly caused by erosion. The budget of the drainage network shows high retention/elimination of nitrogen (from 62 to 77% in the upstream basins and 59% in the delta), and of phosphorus, with retention rates as high as 80% in the Da and Lo sub-basins which have large reservoirs in their downstream course (Hoa Binh on the Da and Thac Ba on the Lo). The total specific delivery estimated at the outlet of the whole Red River System is 855 kg km-2 yr-1 total N and 325 kg km-2 yr-1 total P. Nitrogen rather than phosphorus seems to be the potential limiting factor of algal growth in the plume of the Red River in Tonkin Bay.

Quynh, Le Thi Phuong; Billen, Gilles; Garnier, Josette; ThéRy, Sylvain; FéZard, CéDric; Minh, Chau Van

2005-06-01

87

Age and origin of magmatism along the Cenozoic Red River shear belt, China  

Microsoft Academic Search

To decipher the geodynamic significance of Cenozoic magmatism along the Red River shear belt, geochemical analyses, U-Pb\\u000a and Rb-Sr dating, and Pb-Sr-Nd isotope tracing were undertaken. Zircon, monazite, titanite, and a Ti-U-oxide from foliated\\u000a granitoid intrusions in the shear belt gneisses yield U-Pb emplacement ages of 33.1??0.2 (2?), 31.9??0.3, 25.8??0.2 and\\u000a 24.7??0.2?Ma, and an age of 35.0??0.3?Ma was obtained for

Lian-Sheng Zhang; Urs Schärer

1999-01-01

88

INTELLIGENT COMPUTING SYSTEM FOR RESERVOIR ANALYSIS AND RISK ASSESSMENT OF THE RED RIVER FORMATION  

SciTech Connect

Integrated software has been written that comprises the tool kit for the Intelligent Computing System (ICS). Luff Exploration Company is applying these tools for analysis of carbonate reservoirs in the southern Williston Basin. The integrated software programs are designed to be used by small team consisting of an engineer, geologist and geophysicist. The software tools are flexible and robust, allowing application in many environments for hydrocarbon reservoirs. Keystone elements of the software tools include clustering and neural-network techniques. The tools are used to transform seismic attribute data to reservoir characteristics such as storage (phi-h), probable oil-water contacts, structural depths and structural growth history. When these reservoir characteristics are combined with neural network or fuzzy logic solvers, they can provide a more complete description of the reservoir. This leads to better estimates of hydrocarbons in place, areal limits and potential for infill or step-out drilling. These tools were developed and tested using seismic, geologic and well data from the Red River Play in Bowman County, North Dakota and Harding County, South Dakota. The geologic setting for the Red River Formation is shallow-shelf carbonate at a depth from 8000 to 10,000 ft.

Kenneth D. Luff

2002-09-30

89

INTELLIGENT COMPUTING SYSTEM FOR RESERVOIR ANALYSIS AND RISK ASSESSMENT OF THE RED RIVER FORMATION  

SciTech Connect

Integrated software has been written that comprises the tool kit for the Intelligent Computing System (ICS). Luff Exploration Company is applying these tools for analysis of carbonate reservoirs in the southern Williston Basin. The integrated software programs are designed to be used by small team consisting of an engineer, geologist and geophysicist. The software tools are flexible and robust, allowing application in many environments for hydrocarbon reservoirs. Keystone elements of the software tools include clustering and neural-network techniques. The tools are used to transform seismic attribute data to reservoir characteristics such as storage (phi-h), probable oil-water contacts, structural depths and structural growth history. When these reservoir characteristics are combined with neural network or fuzzy logic solvers, they can provide a more complete description of the reservoir. This leads to better estimates of hydrocarbons in place, areal limits and potential for infill or step-out drilling. These tools were developed and tested using seismic, geologic and well data from the Red River Play in Bowman County, North Dakota and Harding County, South Dakota. The geologic setting for the Red River Formation is shallow-shelf carbonate at a depth from 8000 to 10,000 ft.

Kenneth D. Luff

2002-06-30

90

Analysis of Land Surface Paramters and Flood Data in the Red River of the North Basin  

NASA Astrophysics Data System (ADS)

The movement and distribution of water in the hydrologic cycle is affected by the level and type of land surface parameters. Thus accurate representation of the physical and biological features of the landscape within a watershed is required. A strong link exists between climate variability and the resulting changes in such land surface parameters as energy fluxes, land-cover and surface microclimates. Imagery from Landsat and other satellites provide land-cover and surface microclimate information with high temporal and spatial accuracy. This paper utilizes the land surface temperature (LST) derived from the thermal band of Landsat images and Normalized Difference Vegetation Index (NDVI) derived from its red and near-infrared bands to further improve land-cover and surface microclimate mapping. Remotely-sensed spatially distributed surface latent and sensible heat fluxes were also estimated. The study was conducted on the Red River of the North basin, North Dakota/Minnesota. Over the period of 1974-2002, seven images from Landsat Multispectral Scanner, Thematic Mapper and Enhanced Thematic Mapper plus sensors were used. Landsat images were processed using an unsupervised classification. Corrected LST and NDVI, which indicate a strong relationship with the land-cover data, were identified using scattergrams. Surface microclimate parameters (fractional vegetation cover, FVC and fractional impervious surface, FIS area) were estimated and their spatial and temporal distributions determined. Surface energy fluxes (latent and sensible heat) were assessed over space and time. The results indicate that vegetation cover (FVC >0.5) increased from 7% in 1974 to 48% in 1998 due to cropland farming in the Red River Valley and an increase in impervious areas (FIS >0.5) (by 79% from 1974 to 2001) attributed to the growing cities in the valley for the period of study. The study also indicated an increase in sensible and latent heat fluxes from 1998 to 2002 for areas classified as developed and cropland, respectively. Hydrograph analysis of the flow at Grand Forks gauging station also indicated runoff response of the basin has increased between 1993 and 2002 with all years having percent runoff greater than 10% compared to only 42% of the years between 1974 and 1993. Keywords: Fractional vegetation cover; Landsat; Land-cover; Energy flux; Surface microclimate; Red River

Melesse, A. M.

2003-12-01

91

Mobilization of arsenic and iron from Red River floodplain sediments, Vietnam  

NASA Astrophysics Data System (ADS)

Sediments from the Red River and from an adjacent floodplain aquifer were investigated with respect to the speciation of Fe and As in the solid phase, to trace the diagenetic changes in the river sediment upon burial into young aquifers, and the related mechanisms of arsenic release to the groundwater. Goethite with subordinate amounts of hematite were, using Mössbauer spectroscopy, identified as the iron oxide minerals present in both types of sediment. The release kinetics of Fe, As, Mn and PO 4 from the sediment were investigated in leaching experiments with HCl and 10 mM ascorbic acid, both at pH 3. From the river sediments, most of the Fe and As was mobilized by reductive dissolution with ascorbic acid while HCl released very little Fe and As. This suggests As to be associated with an Fe-oxide phase. For oxidized aquifer sediment most Fe was mobilized by ascorbic acid but here not much As was released. However, the reduced aquifer sediments contained a large pool of Fe(II) and As that is readily leached by HCl, probably derived from an unidentified authigenic Fe(II)-containing mineral which incorporates As as well. Extraction with ascorbic acid indicates that the river sediments contain both As(V) and As(III), while the reduced aquifer sediment almost exclusively releases As(III). The difference in the amount of Fe(II) leached from river and oxidized aquifer sediments by ascorbic acid and HCl, was attributed to reductive dissolution of Fe(III). The reactivity of this pool of Fe(III) was quantified by a rate law and compared to that of synthetic iron oxides. In the river mud, Fe(III) had a reactivity close to that of ferrihydrite, while the river sand and oxidized aquifer sediment exhibited a reactivity ranging from lepidocrocite or poorly crystalline goethite to hematite. Mineralogy by itself appears to be a poor predictor of the iron oxide reactivity in natural samples using the reactivity of synthetic Fe-oxides as a reference. Sediments were incubated, both unamended and with acetate added, and monitored for up to 2 months. The river mud showed the fastest release of both Fe and As, while the effect of acetate addition was minor. This suggests that the presence of reactive organic carbon is not rate limiting. In the case of the river and aquifer sediments, the release of Fe and As was always stimulated by acetate addition and here reactive organic carbon was clearly the rate limiting factor. The reduced aquifer sediment apparently can sustain slower but prolonged microbially-driven release of As. The highly reactive pools of Fe(III) and As in the river mud could be due to reoxidation of As and Fe contained in the reducing groundwater from the floodplain aquifers that are discharging into the river. Deposition of the suspended mud on the floodplain during high river stages is proposed to be a major flux of As onto the floodplain and into the underlying aquifers.

Postma, Dieke; Jessen, Søren; Hue, Nguyen Thi Minh; Duc, Mai Thanh; Koch, Christian Bender; Viet, Pham Hung; Nhan, Pham Quy; Larsen, Flemming

2010-06-01

92

The red-cockaded woodpecker on the Savannah River Site: Aspects of reproductive success.  

SciTech Connect

Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 5. Status and Trends of Populations. Pp 224-229. Abstract: The red-cockaded woodpecker (Picoides borealis) population on the Savannah River Site has been closely monitored and studied over the last 17 years. In 1985, the USDA Forest Service Southern Research Station was given responsibility to study and manage this population in an effort to prevent its extirpation. In December 1985, there were only 4 individuals on the site: 1 pair and 2 solitary males. The population had increased to a total of 175 individuals in 42 active clusters in 2002. Although this represents a very successful recovery effort, there has been substantial annual variation in nesting survival from banding to fledging. Data were analyzed to more completely understand the factors affecting reproduction. No significant effects of age of the breeding male and female, years paired, number of helpers, habitat quality, number of nestings, and time of nest initiation were found when comparing reproductive success in 117 nesting attempts from 1999 to 2002. However, the number of neighboring groups had a direct effect on mortality rates, possibly demonstrating the importance of cluster spacing.

Johnston, Peter A.; Imm, Donald, W.; Jarvis, William L.

2004-12-31

93

Modeling River Incision Across Active Normal Faults Using the Channel-Hillslope Integrated Landscape Development Model (CHILD): the case of the Central Apennines (Italy)  

NASA Astrophysics Data System (ADS)

River systems constitute some of the most efficient agents that shape terrestrial landscapes. Fluvial incision rates govern landscape evolution but, due to the variety of processed involved and the difficulty of quantifying them in the field, there is no "universal theory" describing the way rivers incise into bedrock. The last decades have seen the birth of numerous fluvial incision laws associated with models that assign different roles to hydrodynamic variables and to sediments. In order to discriminate between models and constrain their parameters, the transient response of natural river systems to a disturbance (tectonic or climatic) can be used. Indeed, the different models predict different kinds of transient response whereas most models predict a similar power law relationship between slope and drainage area at equilibrium. To this end, a coupled field - modeling study is in progress. The field area consists of the Central Apennines that are subject to active faulting associated with a regional extensional regime. Fault initiation occurred 3 My ago, associated with throw rates of 0.3 +/- 0.2 mm/yr. Due to fault interaction and linkage, the throw rate on the faults located near the center of the fault system increased dramatically 0.7 My ago (up to 2 mm/yr), whereas slip rates on distal faults either decayed or remained approximately constant. The present study uses the landscape evolution model, CHILD, to examine the behavior of rivers draining across these active faults. Distal and central faults are considered in order to track the effects of the fault acceleration on the development of the fluvial network. River characteristics have been measured in the field (e.g. channel width, slope, sediment grain size) and extracted from a 20m DEM (e.g. channel profile, drainage area). We use CHILD to test the ability of alternative incision laws to reproduce observed topography under known tectonic forcing. For each of the fluvial incision models, a Monte-Carlo simulation has been performed, allowing the exploration of a wide range of values for the different parameters relative to tectonic, climate, sediment characteristics, and channel geometry. Observed profiles are consistent with a dominantly wave-like, as opposed to diffusive, transient response to accelerated fault motion. The ability of the different models to reproduce more or less accurately the catchment characteristics, in particular the specific profiles exhibited by the rivers, are discussed in light of our first results.

Attal, M.; Tucker, G.; Whittaker, A.; Cowie, P.; Roberts, G.

2005-12-01

94

77 FR 43591 - Tri-State Financial Co., LLC, (d/b/a North Country Ethanol), Red River Energy, LLC; Notice of Filing  

Federal Register 2010, 2011, 2012, 2013

...Co., LLC, (d/b/a North Country Ethanol), Red River Energy, LLC; Notice of...Financial Co., LLC, d/ b/a North Country Ethanol (Tri-State), and Red River Energy...North Dakota, to the Tri- State's ethanol facility near Rosholt, in Roberts...

2012-07-25

95

Temporal and spatial distribution of red tide outbreaks in the Yangtze River Estuary and adjacent waters, China.  

PubMed

Between 1972 and 2009, evidence of red tide outbreaks in the Yangtze River Estuary and adjacent waters was collected. A geographic information system (GIS) was used to analyze the temporal and spatial distribution of these red tides, and it was subsequently used to map the distribution of these events. The results show that the following findings. (1) There were three red tide-prone areas: outside the Yangtze River Estuary and the eastern coast of Sheshan, the Huaniaoshan-Shengshan-Gouqi waters, and the Zhoushan areas and eastern coast of Zhujiajian. In these areas, red tides occurred 174 total times, 25 of which were larger than 1000 km(2) in areal extent. After 2000, the frequency of red tide outbreaks increased significantly. (2) During the months of May and June, the red tide occurrence in these areas was 51% and 20%, respectively. (3) Outbreaks of the dominant red tide plankton species Prorocentrum dong-haiense, Skeletonema costatum, Prorocentrum dantatum, and Noctiluca scientillan occurred 38, 35, 15, and 10 times, respectively, during the study interval. PMID:23628547

Liu, Lusan; Zhou, Juan; Zheng, Binghui; Cai, Wenqian; Lin, Kuixuan; Tang, Jingliang

2013-04-28

96

Geochemistry of the Red River and Chang Jiang - Constraints on the Weathering Flux Associated with the Indo-Tibetan collision  

NASA Astrophysics Data System (ADS)

Red River and the headwaters of the Chang Jiang in western China and Vietnam are in the tectonically active part of the Himalayan-Tibetan orogeny. Riverine fluxes associated with weathering along these rivers contribute to the total weathering yield associated with the main collision. The riverine flux carried by Himalayan rivers is considered to be a significant fraction of continental weathering budgets globally. Interpreting the geochemistry of rivers in terms of lithology, weathering rates, tectonics and global climate implications pose a challenge and we therefore use a suite of geochemical tools, including but not limited to, major ion and trace element concentrations and analyses of various isotope systems namely Sr, Os, Li, U among others. Over 150 samples were obtained from pristine locations along these rivers during the summer and winter seasons spanning a period of 3 years. Major element chemistry along with some trace element analyses (Sr, Rb, Ba, Cs, U and Th) is comparable to that of the large rivers draining the Himalayan mountain belt. For example, Sr concentrations range from 0.2 to 7.0 uM for Red River and 0.07 to 13 uM for the Chang Jiang. Sr isotope analyses provide additional constraints on the source of the weathering flux (silicate v/s carbonate), which in turn provides constraints on interpretations of the global marine Sr isotope record, atmospheric CO2 drawdown and changing global climate.

Ellis, A.; Huh, Y.

2003-12-01

97

Simulated effects of the proposed Garrison Diversion Unit on streamflow and dissolved solids in the Sheyenne River and the Red River of the North, North Dakota and Minnesota  

USGS Publications Warehouse

Future development of the Garrison Diversion Unit in North Dakota could deliver 100 cubic feet per second of water for the cities of Fargo, Grand Forks, and surrounding communities. Missouri River water from the Garrison Diversion Unit Sheyenne River water supply would be delivered to the upper reaches of the Sheyenne River, which would convey the water to the Red River of the North. Potential effects of releasing Missouri River water to the Sheyenne River on the quantity and quality of streamflow in the Sheyenne River and in the Red River of the North are evaluated for two proposed operating plans--year-round operation (12 months each year) and nonwinter operation (April through October each year). The Project Canals, Reservoirs, and River Systems (PROCRRS) and Canals, Rivers, and Reservoirs Salinity Accounting Procedures (CRRSAP) monthly accounting models are used to predict streamflow and dissolved-solids changes that could result from the proposed release of treated Missouri River water into the Sheyenne River and the Red River of the North. For year-round operation of the Garrison Diversion Unit Sheyenne River water supply for the period 1931-84, the maximum quantity of water that must be delivered to the upper reaches of the Sheyenne River so that 100 cubic feet per second of Missouri River water can be delivered to Fargo, N.Dak., and Grand Forks, N.Dak., was estimated to be about 151 cubic feet per second for August 1976. For nonwinter operation the maximum quantity of water was estimated to be about 210 cubic feet per second. Model simulations were used to assess the effects that operation of the Garrison Diversion Unit Sheyenne River water supply could have on streamflow and water quality of the Sheyenne River and the Red River of the North. Effects were assessed by comparing simulated streamflows that include Missouri River water to baseline conditions, which represent hydrologic conditions before addition of Missouri River water. Simulated mean monthly dissolved-solids concentrations for Sheyenne River nodes for year-round and nonwinter operation of the Garrison Diversion Unit Sheyenne River water supply generally were less than those for baseline conditions.Simulated mean monthly dissolved-solids concentrations for Red River of the North nodes for year-round and nonwinter operation generally were greater than those for baseline conditions. Streamflow for 1933-42 was about 25 percent of the mean annual streamflow for 1931-84. Simulated monthly mean dissolved-solids concentrations for year-round and nonwinter operation for node 125, Sheyenne River near Cooperstown, N.Dak., for the low-flow conditions of 1933-42 were less than those for baseline conditions. Annual variability of simulated dissolved-solids concentrations for year-round operation was less than annual variability for nonwinter operation and for baseline conditions. Simulated monthly mean dissolved-solids concentrations for year-round and nonwinter operation for node 250, Sheyenne River near Kindred, N.Dak., for the low-flow conditions of 1933-42 ranged from 500 to 600 milligrams per liter.Simulated monthly mean dissolved-solids concentrations for baseline conditions ranged from 300 milligrams per liter to greater than 1,000 milligrams per liter. Simulated monthly mean dissolved-solids concentrations for nonwinter operation were less than those for year-round operation. For node 700, Red River of the North at Grand Forks, N.Dak., the magnitude of simulated monthly mean dissolved-solids concentrations for year-round and nonwinter operation for the low-flow conditions of 1933-42 were about the same as those for baseline conditions. Streamflow for 1973-82 was about 30 percent greater than the mean annual streamflow for 1931-84. For the high-flow conditions of 1973-82, simulated monthly mean dissolved-solids concentrations for node 125 for year-round operation ranged from about 325 to 650 milligrams per liter, and simulated monthly mean dissolved-solids c

Guenthner, R. Scott

1993-01-01

98

Surface-Water Quality Assessment of the North Fork Red River Basin Upstream From Lake Altus, Oklahoma, 2002.  

National Technical Information Service (NTIS)

Elevated salinity in the North Fork Red River is a major concern of the Bureau of Reclamation W. C. Austin Project at Lake Altus. Understanding the relation between surface-water runoff, ground-water discharge. and surface- water quality is important for ...

S. J. Smith M. L. Schneider J. R. Masoner R. L. Blazs

2003-01-01

99

The Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) phase 2(c) Red-Arkansas River basin experiment  

Microsoft Academic Search

The energy components of sixteen Soil-Vegetation Atmospheric Transfer (SVAT) schemes were analyzed and intercompared using 10 years of surface meteorological and radiative forcing data from the Red-Arkansas River basin in the Southern Great Plains of the United States. Comparisons of simulated surface energy fluxes among models showed that the net radiation and surface temperature generally had the best agreement among

X. Liang; Eric F. Wood; Dennis P. Lettenmaier; Dag Lohmann; Aaron Boone; Sam Chang; Fei Chen; Yongjiu Dai; Carl Desborough; Robert E. Dickinson; Qingyun Duan; Michael Ek; Yeugeniy M. Gusev; Florence Habets; Parviz Irannejad; Randy Koster; Kenneth E. Mitchell; Olga N. Nasonova; Joel Noilhan; John Schaake; Adam Schlosser; Yaping Shao; Andrey B. Shmakin; Diana Verseghy; Kirsten Warrach; Peter Wetzel; Yongkang Xue; Zong-Liang Yang; Qing-cun Zeng

1998-01-01

100

Environmental and Resource Degradation Associated with Small-Scale Enterprise Clusters in the Red River Delta of Northern Vietnam  

Microsoft Academic Search

The paper reports on an empirical study of the environmental and resource degradation observed in small-scale handicraft clusters in the Red River Delta of northern Vietnam. Most entrepreneurs in these clusters face important challenges, including depletion of natural resources, linked to acute shortages of capital and land. Such issues are identified as the main cause of overcrowding, poor working conditions

DIMITRIOS KONSTADAKOPULOS

2008-01-01

101

Normal Fault Visualization  

NSDL National Science Digital Library

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

Myers, Jimm

102

Millennial slip rate of the Longitudinal Valley fault from river terraces: Implications for convergence across the active suture of eastern Taiwan  

Microsoft Academic Search

The Longitudinal Valley fault is a key element in the active tectonics of Taiwan. It is the principal structure accommodating convergence across one of the two active sutures of the Taiwan orogeny. To understand more precisely its role in the suturing process, we analyzed fluvial terraces along the Hsiukuluan River, which cuts across the Coastal Range in eastern Taiwan in

J. Bruce H. Shyu; Kerry Sieh; Jean-Philippe Avouac; Wen-Shan Chen; Yue-Gau Chen

2006-01-01

103

New constraints on the structure, thermochronology, and timing of the Ailao Shan-Red River shear zone, SE Asia  

NASA Astrophysics Data System (ADS)

New structural, petrographic, and 40Ar/39Ar data constrain the kinematics of the ASRR (Ailao Shan-Red River shear zone). In the XueLong Shan (XLS), geochronological data reveal Triassic, Early Tertiary, and Oligo-Miocene thermal events. The latter event (33-26 Ma) corresponds to cooling during left-lateral shear. In the FanSiPan (FSP) range, thrusting of the SaPa nappe, linked to left-lateral deformation, and cooling of the FSP granite occurred at ?35 Ma. Rapid cooling resumed at 25-29 Ma as a result of uplift within the transtensive ASRR. In the DayNuiConVoi (DNCV), foliation trends NW-SE, but is deflected near large-scale shear planes. Stretching lineation is nearly horizontal. On steep foliations, shear criteria indicate left-lateral shear sense. Zones with flatter foliations show compatible shear senses. Petrographic data indicate decompression from ?6.5 kbar during left-lateral shear (temperatures >700°C). 40Ar/39Ar data imply rapid cooling from above 350°C to below 150°C between 25 and 22 Ma without diachronism along strike. Along the whole ASRR cooling histories show two main episodes: (1) rapid cooling from peak metamorphism during left-lateral shear; (2) rapid cooling from greenschist conditions during right-lateral reactivation of the ASRR. In the NW part of the ASRR (XLS, Diancang Shan), we link rapid cooling 1 to local denudations in a transpressive environment. In the SW part (Ailao Shan and DNCV), cooling 1 resulted from regional denudation by zipper-like tectonics in a transtensive regime. The induced cooling diachronism observed in the Ailao Shan suggests left-lateral rates of 4 to 5 cm/yr from 27 Ma until ?17 Ma. DNCV rocks always stayed in a transtensive regime and do not show cooling diachronism. The similarities of deformation kinematics along the ASRR and in the South China Sea confirms the causal link between continental strike-slip faulting and marginal basin opening.

Leloup, P. H.; Arnaud, N.; Lacassin, R.; Kienast, J. R.; Harrison, T. M.; Trong, T. T. Phan; Replumaz, A.; Tapponnier, P.

2001-04-01

104

Establishment of a Viable Population of Red-Cockaded Woodpeckers at the Savannah River Site  

SciTech Connect

Report on program's objective to restore viable population of Red-cockaded woodpecker at SRS. Several management strategies were used to promote population expansion of Red-cockaded woodpecker and reduction of interspecific competition with Red-Cockaded woodpecker.

Johnston, P.A.

2002-01-14

105

Active normal faults and river damming: the importance of tectonics and climate in shaping the landscape of the southern Tibetan plateau  

NASA Astrophysics Data System (ADS)

Understanding the interaction between tectonics, climate and erosion is key to unravel the geodynamic evolution of rapidly evolving landscapes. Normal faulting along the Ama Drime and fluvial incision of the Arun river are used to better describe the recent evolution of the south-central Tibetan plateau. The Arun catchment can be separated in two parts, an upper catchment characterized by the presence of abandoned shorelines testifying of the presence of a paleolake, and a lower basin with deep gorges characterized by strong fluvial incision. This geometry implies ancient damming of the Arun river in the vicinity of the Kharta normal fault. Two shorelines, the highest at 4400 m asl and a major one at 4260 m a.s.l. have been dated at about 200-250 ka and at 80-120 ka using both OSL and 10Be cosmogenic dating methods of surface and subsurface samples. In the south Kharta basin, river terraces ˜100 m above the present riverbed are offset between 10 and 15 m by one branch of the normal fault. 10Be cosmogenic nuclide exposure ages of these terraces range between 9 and 11 ka, consistent with aggradation after the Last Glacial Maximum (LGM ˜20 ka), followed by rapid incision of the Arun. A few kilometres south of Kharta, the normal fault offsets by about 30 m abandoned lateral moraines with ages ranging from 20 to 70 ka. These measurements constrain the rates of vertical displacement along the normal faults to range between 0.7 and 1.4 mm/yr since 10-15 ka. The 20-70 ka rate is less well constrained but is of the same order. To the north, the range of ages (30 to 166 ka) of a terrace offset by 150 m suggests a formation during MIS-5e, and thus a vertical slip-rate of about 1±0.5 mm/yr. 70 kilometres farther north-east, moraines are offset by 20-40 m across the Mabja west-dipping normal fault in the nothward prologation of the Kharta fault. If the moraines are correlated with the LGM advance the Mabja fault vertical slip-rate is similar to that of the Kharta fault. All these data indicate vertical rates on the order of 0.6 to 1.7 mm/yr on the North-Ssouth active faults in the Ama Drime area. The peculiar course of the Arun river meandering within gorges into the footwall of the Kharta fault downstream of the paleolake remnants indicates interaction between river damming and active normal faulting. The high lake stands may be correlated to the penultimate and last interglacial stages corresponding to enhance moisture across the Himalayas. It further suggest dam buildup during cold and dry glacial stages favoring diminished fluvial erosion and enhanced morainic debris accumulation in the gorge during continuous tectonic uplift. The end of the last lake high-stand (100-120ka) is in agreement with the highest and oldest evidence of fluvial terraces downstream of the gorge. These results show the importance of fluvial and tectonic interaction in connecting closed basins to drained valleys and thus in shaping large parts of the Tibetan plateau.

Kali, E.; van der Woerd, J.; Liu-Zeng, J.; LeBéon, M.; Leloup, P.-H.; Mahéo, G.; Tapponnier, P.; Thuizat, R.

2012-04-01

106

Impact of the Red River Catastrophic Flood on Women Giving Birth in North Dakota, 1994–2000  

Microsoft Academic Search

To document changes in birth rates, birth outcomes, and pregnancy risk factors among women giving birth after the 1997 Red\\u000a River flood in North Dakota. We analyzed detailed county-level birth files pre-disaster (1994–1996) and post-disaster (1997–2000)\\u000a in North Dakota. Crude birth rates and adjusted fertility rates were calculated. The demographic and pregnancy risk factors\\u000a were described among women delivering singleton

Van T. Tong; Marianne E. Zotti; Jason Hsia

2011-01-01

107

Comparison of the survival, growth and yield of red swamp crayfish and white river crayfish in monoculture and polyculture systems  

Microsoft Academic Search

Red swamp crayfish (Procambarus clarkii) and white river crayfish (P. acutus acutus) production for monoculture and polyculture systems were compared. The experiment consisted of three treatments with six\\u000a replicates each. The stocking rates were 43 crayfish\\/m2 in 0.18-m2 tanks fitted with a stand of green rice. Each tank contained six crayfish, either six individuals of the same species or\\u000a three individuals of each

Yavuz Mazlum; Arnold G. Eversole

2008-01-01

108

The Ailao Shan\\/Red River metamorphic belt: Tertiary left-lateral shear between Indochina and South China  

Microsoft Academic Search

The relative importance of thickening and strike-slip extrusion in continental collision is debated. Ductile shear in the Ailao Shan\\/Diancang Shan metamorphic belt, along the Red River in Yunnan, China, yields outstanding evidence of the latter process. For > 500 km, mylonites in this narrow northwest-southeast belt show horizontal lineations on steep, northwest-striking foliation planes, and left-lateral kinematic indicators. U-Pb radiometric

P. Tapponnier; R. Lacassin; P. H. Leloup; U. Schärer; Zhong Dalai; Wu Haiwei; Liu Xiaohan; Ji Shaocheng; Zhang Lianshang; Zhong Jiayou

1990-01-01

109

Red mangrove ( Rhizophora mangle L.) litter fall response to selective pruning (Indian River Lagoon, Florida, U.S.A.)  

Microsoft Academic Search

This 33 month study quantified red mangrove (Rhizophora mangle L.) litter fall response to a selective pruning event using fringing forests located along the Indian River Lagoon, Florida, U.S.A. Selective pruning consisted of the removal of as many as 50% of the lateral branches originating between 2.1m (7ft) and 4.5m (15ft) above the forest floor while maintaining at least 50%

Randall W. Parkinson; Monica Perez-Bedmar; Jenna A. Santangelo

1999-01-01

110

Influence of Organic Agriculture on the Net Greenhouse Effect in the Red River Valley, Minnesota  

NASA Astrophysics Data System (ADS)

Fluxes for the suite of biologically-produced greenhouse gases (CH4, N2O and CO2) are strongly influenced by agriculture, yet the influence of organic agriculture on all three gases, which comprise the net greenhouse effect (GHE), is not clear in the context of large-scale agricultural production. Greenhouse gas mitigation potential will depend upon the net balance for all three gases [GHE balance (CO2 equiv.)= CO2 flux+ 23CH4flux + 296N2Oflux]. On-farm, field-scale experiments were performed to test the hypothesis that the net GHE at the soil-atmosphere interface is reduced under organic wheat production, compared with conventional, and that effects vary inter-seasonally. Trace gas fluxes were measured at the soil-atmosphere interface for organic and conventional wheat farms in the Red River Valley, Minnesota, one of the most productive agricultural regions in the US. We utilized 40-60 ha field pairs planted with hard red spring wheat (Triticum aestivum L.). Treatment pairs were located 6km apart and consisted of fields continuously cropped for wheat/soybean/sugar beet production for over 20 yr. Ten random, permanent points were generated for each 8.1 ha sub-plot nested inside each field. Each field pair was similar with respect to crop, climate, cultivation history, tillage, rotation, soil texture, pH, macronutrients, bulk density, and water holding capacity. Differences between treatments for the last five years were soil amendments (compost or urea) and herbicide/fungicide application versus mechanical weed control. We collected gas fluxes at each of the 41 points from April (wheat emergence) until the end of July (maturity) to determine the hourly and seasonally integrated net GHE for each management practice, given similar soil/plant/climatic conditions. Moreover, we analyzed inter-seasonal variability to determine the relationship between wheat phenology and flux under field conditions for soil temperature and moisture (water-filled pore space). The net GHE for organic fields was less spatially and temporally variable than conventional, with average daily flux between 0.48 and 1.44 g CO2 equiv. m-2 d-1. Average daily flux in conventional fields ranged between 0.48 and 3.12 g CO2 equiv. m-2 d-1, with highest values in April and May. While soil moisture in organic fields was significantly greater than conventional, it did not interact with treatment to affect trace gas flux. Instead, the effect of organic on N2O, CO2 and the net GHE was strongly influenced by crop stage, an agronomically meaningful proxy integrating time and plant growth conditions. Most CH4 flux observations were 0. Integrated fluxes for each of the 40 sites over the growing season was averaged by field pair and treatment. Although the magnitude of the treatment effect for average seasonal integrated flux varied between field pairs for CO2 and N2O fluxes, the overall influence of treatment on the net GHE was similar. Overall, soils under organically produced wheat emitted 200 kg CO2 equiv. ha-1 per season less than conventionally produced wheat. We observed 1) the net GHE for similar field sites in the Red River Valley was reduced under organic versus conventional agriculture, 2) N2O flux in organic fields was significantly lower than conventional fields for both field pair sites, and 3) the effect of treatment on CO2 flux was site specific.

Phillips, R. L.

2004-12-01

111

Design and costs for a system to reduce chloride levels in the Red River by shallow-well collection and deep-well disposal  

Microsoft Academic Search

The Red River drains 242000?km2 with 90% of this area being downstream of discharges from naturally occurring brine seeps and springs. The upstream area\\u000a has been designated as a major chloride emission area in Texas and Oklahoma. Ten major brine source emission areas along the\\u000a tributaries to the Red River were identified by U.S. Public Health Service and U.S. Army

T. S. Green; B. A. Memon; A. F. Patton; M. W. Pitts

1999-01-01

112

Fan-delta and interdeltaic shoreline sediments of Middle Devonian Granite Wash and Keg River clastics, Red Earth field, north Alberta basin, Canada  

Microsoft Academic Search

A detailed sedimentological investigation of over 4000 ft of core and 500 well logs of the Middle Devonian granite wash and Keg River clastics in the Red Earth field, North Alberta basin, Canada, has led to the recognition of a granite wash subaerial fan-delta system that is laterally continuous with a Keg River subaqueous delta component along an eastern shoreline

Hassan Sabry

1989-01-01

113

Dating of major normal fault systems using thermochronology: An example from the Raft River detachment, Basin and Range, western United States  

USGS Publications Warehouse

Application of thermochronological techniques to major normal fault systems can resolve the timing of initiation and duration of extension, rates of motion on detachment faults, timing of ductile mylonite formation and passage of rocks through the crystal-plastic to brittle transition, and multiple events of extensional unroofing. Here we determine the above for the top-to-the-east Raft River detachment fault and shear zone by study of spatial gradients in 40Ar/39Ar and fission track cooling ages of footwall rocks and cooling histories and by comparison of cooling histories with deformation temperatures. Mica 40Ar/39Ar cooling ages indicate that extension-related cooling began at ???25-20 Ma, and apatite fission track ages show that motion on the Raft River detachment proceeded until ???7.4 Ma. Collective cooling curves show acceleration of cooling rates during extension, from 5-10??C/m.y. to rates in excess of 70-100??C/m.y. The apparent slip rate along the Raft River detachment, recorded in spatial gradients of apatite fission track ages, is 7 mm/yr between 13.5 and 7.4 Ma and is interpreted to record the rate of migration of a rolling hinge. Microstructural study of footwall mylonite indicates that deformation conditions were no higher than middle greenschist facies and that deformation occurred during cooling to cataclastic conditions. These data show that the shear zone and detachment fault represent a continuum produced by progressive exhumation and shearing during Miocene extension and preclude the possibility of a Mesozoic age for the ductile shear zone. Moderately rapid cooling in middle Eocene time likely records exhumation resulting from an older, oppositely rooted, extensional shear zone along the west side of the Grouse Creek, Raft River, and Albion Mountains. Copyright 2000 by the American Geophysical Union.

Wells, M. L.; Snee, L. W.; Blythe, A. E.

2000-01-01

114

Constituent loads and flow-weighted average concentrations for major subbasins of the upper Red River of the North Basin, 1997-99  

USGS Publications Warehouse

Data were collected at 11 water-quality sampling sites in the upper Red River of the North (Red River) Basin from May 1997 through September 1999 to describe the water-quality characteristics of the upper Red River and to estimate constituent loads and flow-weighted average concentrations for major tributaries of the Red River upstream from the bridge crossing the Red River at Perley, Minn. Samples collected from the sites were analyzed for 5-day biochemical oxygen demand, bacteria, dissolved solids, nutrients, and suspended sediment. Concentration data indicated the median concentrations for most constituents and sampling sites during the study period were less than existing North Dakota and Minnesota standards or guidelines. However, more than 25 percent of the samples for the Red River at Perley, Minn., site had fecal coliform concentrations that were greater than 200 colonies per 100 milliliters, indicating an abundance of pathogens in the upper Red River Basin. Although total nitrite plus nitrate concentrations generally increased in a downstream direction, the median concentrations for all sites were less than the North Dakota suggested guideline of 1.0 milligram per liter. Total and dissolved phosphorus concentrations also generally increased in a downstream direction, but, for those constituents, the median concentrations for most sampling sites exceeded the North Dakota suggested guideline of 0.1 milligram per liter. For dissolved solids, nutrients, and suspended sediments, a relation between constituent concentration and streamflow was determined using the data collected during the study period. The relation was determined by a multiple regression model in which concentration was the dependent variable and streamflow was the primary explanatory variable. The regression model was used to compute unbiased estimates of annual loads for each constituent and for each of eight primary water-quality sampling sites and to compute the degree of uncertainty associated with each estimated annual load. The estimated annual loads for the eight primary sites then were used to estimate annual loads for five intervening reaches in the study area. Results were used as a screening tool to identify which subbasins contributed a disproportionate amount of pollutants to the Red River. To compare the relative water quality of the different subbasins, an estimated flow-weighted average (FWA) concentration was computed from the estimated average annual load and the average annual streamflow for each subbasin. The 5-day biochemical oxygen demands in the upper Red River Basin were fairly small, and medians ranged from 1 to 3 milligrams per liter. The largest estimated FWA concentration for dissolved solids (about 630 milligrams per liter) was for the Bois de Sioux River near Doran, Minn., site. The Otter Tail River above Breckenridge, Minn., site had the smallest estimated FWA concentration (about 240 milligrams per liter). The estimated FWA concentrations for dissolved solids for the main-stem sites ranged from about 300 to 500 milligrams per liter and generally increased in a downstream direction. The estimated FWA concentrations for total nitrite plus nitrate for the main-stem sites increased from about 0.2 milligram per liter for the Red River below Wahpeton, N. Dak., site to about 0.9 milligram per liter for the Red River at Perley, Minn., site. Much of the increase probably resulted from flows from the tributary sites and intervening reaches, excluding the Otter Tail River above Breckenridge, Minn., site. However, uncertainty in the estimated concentrations prevented any reliable conclusions regarding which sites or reaches contributed most to the increase. The estimated FWA concentrations for total ammonia for the main-stem sites increased from about 0.05 milligram per liter for the Red River above Fargo, N. Dak., site to about 0.15 milligram per liter for the Red River near Harwood, N. Dak., site. T

Sether, Bradley A.; Berkas, Wayne R.; Vecchia, Aldo V.

2004-01-01

115

Change in Sahelian Rivers hydrograph: The case of recent red floods of the Niger River in the Niamey region  

NASA Astrophysics Data System (ADS)

Changes in the hydrological regime of Sahelian Rivers are considered based upon the example of the Middle Niger River and its exceptional flood in 2010 near the city of Niamey. It is shown that rainfall in 2010 was only average with respect to the long term record, with neither the monthly rainfall distribution in terms of the amount of rainfall nor the distribution of rainy events changing significantly in the last few decades. Particularly, no increase in the number of extreme rainfall events is observed. In spite of this, the Niger River's right bank tributaries have shown a sharp increase in runoff since the 1970s, which is still ongoing, and has resulted in a modification of the Niger River's regime from a single hydrograph to a two flood hydrograph, the local flood, occurring during the rainy season being the more pronounced one. This modification is likely due to an increase of bare soils and crusted soil areas as a consequence of human pressure, resulting mostly from the spatial extension of crop areas and the shortening of fallow periods. Changes in connectivity of the river networks on both banks of the Niger such as endorheism bursting events also caused an increase in the contributing basin area. Policy makers should be alerted to the effects of intensive cropping, land clearing and overgrazing in some areas, on the hydrological regimes of Sahelian Rivers.

Descroix, Luc; Genthon, Pierre; Amogu, Okechukwu; Rajot, Jean-Louis; Sighomnou, Daniel; Vauclin, Michel

2012-12-01

116

PREP (Fault Tree Pre-processor): A computer program to facilitate use of the SETS computer program for the Savannah River Reactor PRA  

SciTech Connect

As part of the contract to provide technical support to the PRA for the Savannah River Reactors, Science Applications International Corporation (SAIC) has developed a computer program to facilitate the use of the SETS computer program in the solution of Fault Trees and Event Trees for the PRA. The PREP (Fault Tree Pre-processor) program is used to simplify user input for the SETS fault tree evaluation program. This includes a simple fault tree input format, linking of data and flag settings, error detection to assure that the SETS job will not abort due to incorrect input, and linking of many fault trees into many event tree sequences. The program is designed to run on a VAX computer operating with VMS. The created SETS input file can be transmitted to CRAY computer (currently at LANL) to run SETS. With simple modification, PREP can be adapted to run directly on a CRAY. It is anticipated that use of the PREP program by the Risk Analysis Group will identify the need for additional improvements. These improvements will be implemented as they are identified. In partial fulfillment of contract scope of work requirements, SAIC has submitted a manual for use of PREP and the program listing for PREP. These are included as attachments A and B respectively. Attachment B is included in selected copies only.

Baker, W.H.

1988-05-17

117

Slip-rate Estimation of Active Fault by Luminescence Dating on Deformed River Terraces at Tsaotun, Central Taiwan  

NASA Astrophysics Data System (ADS)

This study carried out luminescence ages of the deformed terraces located at Tsaotun in central Taiwan. These terraces are considered as a result of crustal deformation caused by recent activity of the Chelungpu fault, 1999 surface rupture. Since this active fault runs through urban area, it is urgently needed to figure out its neotectonic behavior, including slip-rate and recurrence interval. Based on new ages, we also discuss the terrace correlation and its related structures. The study terraces are all strath terraces with only a few meters of veneered fluvial deposits on top. Due to the strong stream-power, nearly all the outcrops are dominated by fluvial cobbles, which is worst condition to preserve the syndepositional carbonaceous materials. Alternatively, optical stimulated luminescence (OSL) dating uses sandy quartz as the material and even has longer dating upper limit (up to several hundreds of years). Fortunately, sandy layer are found intercalated within the fluvial cobbles in studying terraces. We adopted the Single-Aliquot Regenerative (SAR) dose protocol on large aliquots of 90-150? m quartz, which were cleaned using HCL, H2O2 and HF in the usual way. In case of incomplete bleaching during quick deposition, the OSL/TL ratio was adopted to approach the true De. Dosimetry is derived by ICP-MS and XRF analyses. For ascertainment of the initial bleaching of fluvial sediment, the modern samples collected in river bed of Wuhsi were also measured. Based on the results of modern samples, we believe that the residuals are inevitable in younger sediments, especially along the upper stream. On the contrary, the samples older than 10 kyr are little influenced due to the larger age error than the younger ones. The OSL age of the terrace samples in the hanging wall is dated ca. 13 kyr, which has been corrected for poorly-bleaching problem. Comparing to the ages collected down hole in the footwalls, we found out vertical displacements of ca. 67 and 37 m, has been cumulated by the slips of main and back thrust. Thus, the long-term slip rates of the main and back thrust are 3.8-6.5 m/kyr and 2.0-3.8 m/kyr, respectively. If we consider that the 1999 Chi-Chi earthquake is a characteristic event, a recurrence interval of 300-600 years is derived.

Chen, Y.; Chen, W.; Lee, C.

2003-12-01

118

Lateral Drilling and Completion Technologies for Shallow-Shelf Carbonates of the Red River and Ratcliffe Formations, Williston Basin  

SciTech Connect

Luff Exploration Company (LEC) focused on involvement in technologies being developed utilizing horizontal drilling concepts to enhance oil- well productivity starting in 1992. Initial efforts were directed toward high-pressure lateral jetting techniques to be applied in existing vertical wells. After involvement in several failed field attempts with jetting technologies, emphasis shifted to application of emerging technologies for drilling short-radius laterals in existing wellbores and medium-radius technologies in new wells. These lateral drilling technologies were applied in the Mississippi Ratcliffe and Ordovician Red River formations at depths of 2590 to 2890 m (8500 to 9500 ft) in Richland Co., MT; Bowman Co., ND; and Harding Co., SD.

David Gibbons; Larry A. Carrell; Richard D. George

1997-07-31

119

Trace metal and metalloid levels in surface water of Marcal River before and after the Ajka red mud spill, Hungary.  

PubMed

The aim of this study was to compare and assess the dissolved concentrations of trace elements (As, Zn, Hg, Cd, Cr, Ni, Pb and Cu) in surface water of Marcal River before and after the red mud spill that occurred in Ajka, western Hungary, in October 2010. The caustic sludge flooded the surrounding settlements and polluted the nearby Torna Creek, which flows through the Marcal and Raba rivers into the Danube. A total of 92 surface water samples were collected from the Marcal River in the period of 2007-2012 and analysed for dissolved trace metal(loid)s by atomic absorption spectroscopy method. After the spill, the water management authority initially focused on acid dosing of surface waters to lower pH and was effective in lowering both pH and metal(loid) concentrations. Among the dissolved trace metal(loid)s, arsenic and nickel levels were moderately higher in the Marcal River 2 years since the spill compared to that observed in the pre-disaster period. The concentrations of dissolved trace metal(loid)s did not exceed the European water quality standards and the US Environmental Protection Agency aquatic life criteria values (excluding one sample for cadmium). PMID:23975713

Nagy, Andrea Szabó; Szabó, János; Vass, István

2013-08-23

120

Faults of Southern California  

NSDL National Science Digital Library

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

121

Density-Dependent Overwinter Survival and Growth of Red Shiners from a Southwestern River  

Microsoft Academic Search

The red shiner Cyprinella lutrensis is the most widespread and abundant minnow (Cyprinidae family) in central and southwestern North America, occurring at very high local densities in streams from northern Mexico to Nebraska and Iowa. The streams in which red shiners occur are typically harsh, unpredictable environments with temperature extremes and episodes of low oxygen, floods, and drought. In outdoor

William J. Matthews; Keith B. Gido; Edie Marsh-Matthews

2001-01-01

122

Oscillating brittle and viscous behavior through the earthquake cycle in the Red River Shear Zone: Monitoring flips between reaction and textural softening and hardening  

NASA Astrophysics Data System (ADS)

Microstructures associated with cataclasites and mylonites in the Red River shear zone in the Diancang Shan block, Yunnan Province, China show evidence for both reaction hardening and softening at lower greenschist facies metamorphic conditions. The earliest fault-rocks derived from Triassic porphyritic orthogneiss protoliths are cataclasites. Brittle fractures and crushed grains are cemented by newly precipitated quartz. These cataclasites are subsequently overprinted by mylonitic fabrics. Truncations and embayments of relic feldspars and biotites show that these protolith minerals have been dissolved and incompletely replaced by muscovite, chlorite, and quartz. Both K-feldspar and plagioclase porphyroclasts are truncated by muscovite alone, suggesting locally metasomatic reactions of the form: 3K-feldspar + 2H+ = muscovite + 6SiO2(aq) + 2K+. Such reactions produce muscovite folia and fish, and quartz bands and ribbons. Muscovite and quartz are much weaker than the reactant feldspars and these reactions result in reaction softening. Moreover, the muscovite tends to align in contiguous bands that constitute textural softening. These mineral and textural modifications occurred at constant temperature and drove the transition from brittle to viscous deformation and the shift in deformation mechanism from cataclasis to dissolution-precipitation and reaction creep. These mylonitic rocks so produced are cut by K-feldspar veins that interrupt the mylonitic fabric. The veins add K-feldspar to the assemblage and these structures constitute both reaction and textural hardening. Finally these veins are boudinaged by continued viscous deformation in the mylonitic matrix, thus defining a late ductile strain event. Together these overprinting textures and microstructures demonstrate several oscillations between brittle and viscous deformation, all at lower greenschist facies conditions where only frictional behavior is predicted by experiments. The overlap of the depths of greenschist facies conditions with the base of the crustal seismic zone suggests that the implied oscillations in strain rate may have been related to the earthquake cycle.

Wintsch, Robert P.; Yeh, Meng-Wan

2013-03-01

123

Oscillating brittle and viscous behavior through the earthquake cycle in the Red River Shear Zone: Monitoring flips between reaction and textural softening and hardening  

NASA Astrophysics Data System (ADS)

Microstructures associated with cataclasites and mylonites in the Red River shear zone in the Diancang Shan block, Yunnan Province, China show evidence for both reaction hardening and softening at lower greenschist facies metamorphic conditions. The earliest fault-rocks derived from Triassic porphyritic orthogneiss protoliths are cataclasites. Brittle fractures and crushed grains are cemented by newly precipitated quartz. These cataclasites are subsequently overprinted by mylonitic fabrics. Truncations and embayments of relic feldspars and biotites show that these protolith minerals have been dissolved and incompletely replaced by muscovite, chlorite, and quartz. Both K-feldspar and plagioclase porphyroclasts are truncated by muscovite alone, suggesting locally metasomatic reactions of the form: 3K-feldspar + 2H+ = muscovite + 6SiO2(aq) + 2K+. Such reactions produce muscovite folia and fish, and quartz bands and ribbons. Muscovite and quartz are much weaker than the reactant feldspars and these reactions result in reaction softening. Moreover, the muscovite tends to align in contiguous bands that constitute textural softening. These mineral and textural modifications occurred at constant temperature and drove the transition from brittle to viscous deformation and the shift in deformation mechanism from cataclasis to dissolution–precipitation and reaction creep. These mylonitic rocks so produced are cut by K-feldspar veins that interrupt the mylonitic fabric. The veins add K-feldspar to the assemblage and these structures constitute both reaction and textural hardening. Finally these veins are boudinaged by continued viscous deformation in the mylonitic matrix, thus defining a late ductile strain event. Together these overprinting textures and microstructures demonstrate several oscillations between brittle and viscous deformation, all at lower greenschist facies conditions where only frictional behavior is predicted by experiments. The overlap of the depths of greenschist facies conditions with the base of the crustal seismic zone suggests that the implied oscillations in strain rate may have been related to the earthquake cycle.

Wintsch, Robert P.; Yeh, Meng-Wan

2013-03-01

124

Red Shiner Invasion of the Upper Coosa River System: Dynamics and Ecological Consequences.  

National Technical Information Service (NTIS)

The red shiner (Cyprinella lutrensis) has been widely introduced across 11 states outside its native range, presumably through bait-bucket and aquarium releases. Its native range includes Great Plain and Central Lowland tributaries of the Mississippi Rive...

D. M. Walters M. J. Blum

2007-01-01

125

Red shiner invasion and hybridization with blacktail shiner in the upper Coosa River, USA  

EPA Science Inventory

Human disturbance increases the invasibility of lotic ecosystems and the likelihood of hybridization between invasive and native species. We investigated whether disturbance has contributed to the invasion of red shiner (Cyprinella lutrensis) and their hybridization with native b...

126

Establishment of a viable population of red-cockaded woodpeckers at the Savannah River Site. Annual report, FY 1990  

SciTech Connect

In 1985 the Southeastern Forest Experiment Station (SEFES) in cooperation with the Department of Energy, the Savannah River Forest Station (SRFS) and the Savannah River Ecology Laboratory (SREL) initiated a research/management program to restore a viable population of red-cockaded woodpeckers (RCW) to the Savannah River Site (SRS). We managed to stabilize the population in the first couple of years through an intensive flying squirrel removal project as well as augmentation of female RCW`s to the SRS population. We are now in the expansion phase of the project. In 1990 we have focused our efforts on: (1) developing a cavity excavation method and excavating cavities in suitable habitat; (2) flying squirrel control; (3) translocation of RCW`s; (4) monitoring clan composition and reproduction; (5) identification of old-growth stands with the potential of providing new nesting habitat to support population expansion; and (6) surveying lands near SRS where RCW`s were thought to exist. This report summarizes activities for FY 1990 and plans for FY 1991.

Allen, D.H.

1990-12-31

127

Establishment of a viable population of red-cockaded woodpeckers at the Savannah River Site. Annual report, FY1992  

SciTech Connect

The Southeastern Forest Experiment Station (SEFES) began research on the red-cockaded woodpecker (RCW) on the Savannah River Site (SRS) in 1985 with the objective of restoring a viable population. This Project is conducted in cooperation with the Department of Energy, the Savannah River Forest Station (SRFS) and the Savannah River Ecology Laboratory. The program has consisted of two phases. The stabilization phase (1985--1987) focused on preventing the immediate extirpation of the RCW population. During this phase the number of breeding pairs of RCWs increased from one to three, and the total population increased from five to 14 birds. We are currently in the expansion phase (1987--present). To facilitate the population expansion of the RCW at SRS, SEFES and SRFS have implemented numerous research and management activities. These include: control of mid-story vegetation to improve habitat suitability, installation of artificial cavities for RCWS, translocations of RCWs within the SRS and from other populations, maintenance of cavities by installing metal restrictors to discourage cavity competition, and generic research to ascertain the degree of relatedness between individuals and populations.

Laves, K.S. [Forest Service, Aiken, SC (United States). Southeastern Forest Experiment Station

1992-09-11

128

Signatures of high-magnitude 19th-century floods in Quercus macrocarpa tree rings along the Red River, Manitoba, Canada  

NASA Astrophysics Data System (ADS)

Quercus macrocarpa (Michx.) growing along the Red River, Manitoba, Canada, contain an anatomical signature related to high-magnitude 19th-century floods. Tree-ring samples were collected from 194 Q. macrocarpa over a 100 km transect along the Red River valley. The combined tree-ring record extends from A.D. 1463 to A.D. 1999; sample depth between 1463 and 1650 is limited and made up exclusively of subfossil logs derived from alluvial deposits. Thirteen trees from four sites contain annual rings with reduced earlywood-vessel transverse areas that reflect flooding during the tree's growing season. Flood rings in 1826 are present in 24% of Q. macrocarpa samples and are coincident with the largest flood observed in the Red River valley. Flood rings in 1852 are exhibited in 5.9% of samples and correspond with the second largest Red River flood. These results confirm that Quercus species adapt to prolonged inundation by reducing the transverse area of their earlywood vessels and suggest that anatomical signatures in riverbank trees may be used to identify and delineate high-magnitude paleofloods for low-gradient rivers.

St. George, Scott; Nielsen, Erik

2000-10-01

129

Deformational and sedimentary responses to Late Miocene (13-8.5 Ma) left-lateral oblique movement along the northern foreland of the Red River-Ailao Shan shear zone, Yunnan, China  

NASA Astrophysics Data System (ADS)

The arcuate Ailao Shan-Red River shear zone, one of the largest Cenozoic strike-slip faults within the Tibetan plateau, experienced the left-lateral and right-lateral strike-slip motions, occurred in late Oligocene to Miocene time (24-17 Ma) and late Cenozoic time (2-4 Ma), respectively (Allen et al., 1984; Tapponnier et al., 1986; Harrison et al., 1996, Schoenbolhm, et al., 2004). The question underlying this study is what happened in the interval between these two events. Our reconstruction of the range-front deformation and sedimentation of the Ailao Shan shear zone (ASSZ) demonstrates that the eastern range-front of the southeastern segment with a strike of 290°-110° used to be dominated by low-angle normal faulting, which resulted in contemporaneously coarse-grained sedimentation associated with NE-SW shortening by gravitational gliding that occurred within a narrow half-graben along the foreland of the southeastern segment of the shear zone. These coarse-grained sediments, namely Ailao Shan conglomerate, are late Oligocene to Miocene in age, dated by fossils. They are in unconformable depositional contact on pre-Cenozoic rocks of the Yangtze block to the north, with the unconformity cropping out along the north side of the Red River valley, and consistently dip to the southwest against the mylonitic gneiss along the ASSZ with dipping angle decreasing upward from 60° to sub-horizontal, characteristic of growth strata. The Ailao Shan conglomerate in the Mosha area is dated as 11.8-8.5 Ma by paleomagstratigraphy, which is approximately coeval with a rapid cooling event of the ASSZ, occurred from 13 to 10 Ma (FT dating, Bergman et al., 1997). All these evidence suggest that the ASSZ was highly active during middle to late Miocene (13-8.5 Ma). We interpret that the low angle normal faulting to have been controlled by the change in geometric pattern of the ASSZ. The ASSZ lies within a wide zone of the north-south right-lateral shear, generated by the relative movement between the Indian subcontinent and the South China block, within which the crustal fragments are undergoing clockwise rotation (Wang and Burchfiel, 1997). Thus, the northwestern segment of the ASSZ with a strike of 320°-140° must have experienced clockwise bending. As the bending proceeded with time, the oblique extension was generated in a direction oblique to the southeastern segment of the shear zone, by which the low-angle normal faulting occurred along the range front of the southeastern segment. In summary, the ASSZ may have had two stages of development. The first stage occurred between 24-17 Ma, dominated by left-lateral displacement with a minor component of the normal displacement, which juxtaposed the mylonite with various rocks of the Yangtze block along a high-angle normal fault bounding the shear zone on the east. The second stage occurred between 13-8.5 Ma, dominated by the low-angel normal faulting along the range-front of the southeastern segment of the shear zone, associated with the contemporary coarse-grained sedimentation.

Wang, E.; Yin, J.; Su, Z.

2010-12-01

130

Discussion of tectonic models for Cenozoic strike-slip fault-affected continental margins of mainland SE Asia  

NASA Astrophysics Data System (ADS)

Understanding the roles of Cenozoic strike-slip faults in SE Asia observed in outcrop onshore, with their offshore continuation has produced a variety of structural models (particularly pull-apart vs. oblique extension, escape tectonics vs. slab-pull-driven extension) to explain their relationships to sedimentary basins. Key problems with interpreting the offshore significance of major strike-slip faults are: (1) reconciling conflicting palaeomagnetic data, (2) discriminating extensional, and oblique-extensional fault geometries from strike-slip geometries on 2D seismic reflection data, and (3) estimating strike-slip displacements from seismic reflection data.Focus on basic strike-slip fault geometries such as restraining vs. releasing bends, and strongly splaying geometries approach the gulfs of Thailand and Tonkin, suggest major strike-slip faults probably do not extend far offshore Splays covering areas 10,000's km2 in extent are characteristic of the southern portions of the Sagaing, Mae Ping, Three Pagodas and Ailao Shan-Red River faults, and are indicative of major faults dying out. The areas of the fault tips associated with faults of potentially 100 km+ displacement, scale appropriately with global examples of strike-slip faults on log-log displacement vs. tip area plots. The fault geometries in the Song Hong-Yinggehai Basin are inappropriate for a sinistral pull-apart geometry, and instead the southern fault strands of the Ailao Shan-Red River fault are interpreted to die out within the NW part of the Song Hong-Yinggehai Basin. Hence the fault zone does not transfer displacement onto the South China Seas spreading centre. The strike-slip faults are replaced by more extensional, oblique-extensional fault systems offshore to the south. The Sagaing Fault is also superimposed on an older Paleogene-Early Miocene oblique-extensional rift system. The Sagaing Fault geometry is complex, and one branch of the offshore fault zone transfers displacement onto the Pliocene-Recent Andaman spreading centre, and links with the West Andaman and related faults to form a very large pull-apart basin.

Morley, C. K.

2013-10-01

131

Aquatic insects as environmental monitors of trace metal contamination: Red River, New Mexico  

Microsoft Academic Search

Discontinuous sampling of water for toxic chemicals is unreliable in lotic ecosystems or in systems subjected to sporadic discharges. Such sampling either fails to detect the contaminants or seriously underestimates their concentrations. This study explored the use of resident aquatic insects as biomonitors of trace metal contamination in a river subjected to episodic spills of Mo mill tailings. Aquatic insects

T. R. Lynch; C. J. Popp; G. Z. Jacobi

1988-01-01

132

Water quality, sediment, and soil characteristics near Fargo-Moorhead urban areas as affected by major flooding of the Red River of the North  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objectives of this study were to assess if urban environments affect floodwater quality, and to determine the quantity and quality of overbank sediment deposited in an urban environment after floodwaters recede. Water samples during major flooding of the Red River of the North (RR) were taken on...

133

ECOLOGICAL COMMUNITY SURVEYS WITHIN THE RED RIVER-DEVILS LAKE BASIN-GRIGGS AND NELSON COUNTIES. EPA-REGIONAL GEOGRAPHIC INITIATIVE  

EPA Science Inventory

Utilize funding from the Regional Geographic Initiative Program to conduct a survey of ecological communities within the Red River-Devils Lake Basins. The study will be targeting Griggs and Nelson Counties to identify significant natural communities and to collect and interpret n...

134

The use of the red swamp crayfish ( Procambarus clarkii, Girard) as indicator of the bioavailability of heavy metals in environmental monitoring in the River Guadiamar (SW, Spain)  

Microsoft Academic Search

A translocation experiment of red swamp crayfish (Procambarus clarkii) to different sites located in the River Guadiamar was performed in order to assess the ability of this species as bioindicator of heavy metal and metalloid contamination. Crayfish were placed in cages and exposed to polluted environment during either 6 or 12days in the three sites with different concentration of contaminants.

Paloma Alcorlo; Marina Otero; María Crehuet; Angel Baltanás; Carlos Montes

2006-01-01

135

Continuous Water-Quality Monitoring and Regression Analysis to Estimate Constituent Concentrations and Loads in the Red River of the North, Fargo, North Dakota, 2003-05.  

National Technical Information Service (NTIS)

This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the Bureau of Reclamation, U.S. Department of the Interior, to estimate water-quality constituent concentrations in the Red River of the North at Fargo, No...

K. R. Ryberg

2006-01-01

136

Water-Use Data for the Red River of the North Basin, North Dakota, Minnesota, and South Dakota, 1979-2001.  

National Technical Information Service (NTIS)

The Red River of the North, located in the north-central plains of the United States, plays an important role in population growth and economic development of the region. Because of recent and projected growth in population, industry, and agriculture in t...

A. Lieb A. D. Arntson A. L. Dahl K. M. Macek-Rowland K. R. Ryberg

2004-01-01

137

Water-use data for the Red River of the North Basin, North Dakota, Minnesota, and South Dakota, 1979-2001  

USGS Publications Warehouse

The Red River of the North, located in the north-central plains of the United States, plays an important role in population growth and economic development of the region. Because of recent and projected growth in population, industry, and agriculture in the Red River of the North Basin, alternatives to additional water resources will be needed to supplement future water needs. Past and current water-use data are needed to help select the most viable water-resource alternatives. Withdrawal and return flow data were collected from various sources throughout the Red River of the North Basin from 1979 through 2001. The withdrawal data were aggregated by subbasin, monthly totals, and water-use categories. The return flow data were aggregated by subbasin and monthly totals. The Red River of the North Basin was divided into subbasins based on locations of U.S. Geological Survey streamflow-gaging stations and by specifically-identified reaches. Results of the water-use compilation are provided in this report.

Macek-Rowland, Kathleen M.; Arntson, Allan D.; Ryberg, Karen R.; Dahl, Ann L.; Lieb, Amy

2004-01-01

138

Concordant variation in thermal tolerance and allozymes of the red shiner, Notropis lutrensis , inhabiting tailwater sections of the Brazos River, Texas  

Microsoft Academic Search

Critical thermal maxima (CTM) and genetic variation were compared for red shiners, Notropis lutrensis, from regulated and unregulated sites on the Brazos River in northcentral Texas. Tailwater fish acclimated to 25°C had significantly lower CTM's than those from a site upstream from the dam and unregulated downstream sites. Significantly different intrasite variances were observed, with two- and four-fold larger CTM

Timothy L. King; Earl G. Zimmerman; Thomas L. Beitinger

1985-01-01

139

Numerical Taxonomy of Red-pigmented Bacteria Isolated from a Lowland River, with the Description of a New Taxon, Rugamonas rubra gen. nov., sp. nov  

Microsoft Academic Search

Twenty red-pigmented bacterial strains, isolated from river water, and 15 named reference cultures were analysed using numerical taxonomic procedures. A simplified dendrogram, based on the simple matching coefficient and unweighted average linkage clustering algorithm, showed that the environmental isolates were recovered in two phenetic groups, defined at or above the 89% similarity level. Nine strains were contained in phenon 1,

D. A. AUSTIN; M. O. MOSS

1986-01-01

140

Fault Motion  

NSDL National Science Digital Library

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

141

Segmentation and the coseismic behavior of Basin and Range normal faults: examples from east-central Idaho and southwestern Montana, U.S.A.  

USGS Publications Warehouse

The range-front normal faults of the Lost River and Lemhi Ranges, and the Beaverhead and Tendoy Mountains in east-central Idaho and southwestern Montana have well-preserved fault scarps on Quaternary deposits along much of their lengths. Fault-scarp morphology, the age of deposits displaced by the faults, and the morphology of the range fronts provide a basis for dividing the faults into segments that are typically 20-25 km long. The Lost River, Lemhi and Beaverhead fault zones are 141-151 km long, and each has six segments. The 60-km-long Red Rock fault (the range-front fault of the Tendoy Mountains) has two central segments that have been active in late Quaternary time; these two segments span the central 27 km of the fault. We recognize four characteristics that help to identify segment boundaries: (1) major en e??chelon offsets or pronounced gaps in the continuity of fault scarps; (2) distinct, persistent, along-strike changes in fault-scarp morphology that indicate different ages of faulting; (3) major salients in the range front; and (4) transverse bedrock ridges where the cumulative throw is low compared to other places along the fault zone. Only features whose size is measured on the scale of kilometers are regarded as significant enough to represent a segment boundary that could inhibit or halt a propagating rupture. The ability to identify segments of faults that are likely to behave as independent structural entities will improve seismic-hazard assessment. However, one should not assume that the barriers at segment boundaries will completely stop all propagating ruptures. The topographic expression of mountain ranges is evidence that, at times during their history, all barriers fail. Some barriers apparently create 'leaky' segment boundaries that impede propagating ruptures but do not completely prevent faulting on adjacent segments. ?? 1991.

Crone, A. J.; Haller, K. M.

1991-01-01

142

An experimental study of the impact of location on the effectiveness of recruitment clusters for red-cockaded woodpeckers at the Savannah River Site.  

SciTech Connect

This report summarizes results of research on red-cockaded woodpeckers (Picoides borealis) conducted by personnel from Virginia Polytechnic Institute and State University (Virginia Tech) and the Duke Marine Laboratory at the Savannah River Site (SRS), South Carolina, from September 29, 2000 through September 28, 2002. This period represents the first two years of a five-year Cooperative Agreement between Virginia Tech and the USDA Forest Service, Savannah River. This report serves as an Interim Project Report with respect to the Cooperative Agreement (No. OO-CA-ll 083600-010), and a Final Project Report for the initial award to Virginia Tech (FRS No.428911).

Walters, J., R.; Taylor, T., B.; Daniels, S., J.

2003-05-29

143

First local seismic tomography for Red River shear zone, northern Vietnam: Stepwise inversion employing crustal P and Pn waves  

NASA Astrophysics Data System (ADS)

The 900-km-long Red River shear zone (RRSZ) lends a compelling support to the continental extrusion model for the tectonic evolution of southeastern Asia, but has been challenged by many of views, as some new records mainly from northern Vietnam, suspecting the dimensions of RRSZ neither in depth nor in displacement are as large as we expected before. However, compared to the northwestern half of the RRSZ in Yunnan province better studied by many fields, the southeastern half in northern Vietnam is relatively poorly constrained by seismic study, due to insufficient stations and data in the past. This study, using a newly deployed portable broadband seismic network, obtained the first local seismic tomography with a stepwise inversion using P and Pn phases. Surface geology, major structures, and rock properties are well correlated and identified in our model, suggesting the RRSZ is a lithospheric structure at least penetrating to the uppermost mantle with mantle thermal anomalies. In general, the crust of northern Vietnam appears to be weak and sits on a relatively hot uppermost mantle, showing a long and complex thermo tectonic history. A mid-lower crustal segmentation of RRSZ is also proposed to compromise the discrepancies recently observed between Yunnan province and northern Vietnam.

Huang, Hsin-Hua; Xu, Zhen J.; Wu, Yih-Min; Song, Xiaodong; Huang, Bor-Shouh; Nguyen, Le Minh

2013-01-01

144

Eeap-lighting survey study at the Red River Army Depot Texarkana, Texas. Final report, 17 October 1994-14 April 1995  

Microsoft Academic Search

This energy conservation study was performed by Huitt-Zollars Inc, for the U.S. Army Engineer District (USAED), Fort Worth, under contract number DACAC63-94-D-00l5. The study was conducted at Red River Army Depot (RRAD) in Texarkana, Texas, between October 17, 1994 and April 14, 1995. The site survey and data collection were performed by C.A. Pieper, P.E. and Tom Luckett, Lighting Designer.

C. A. Pieper; T. Luckett

1995-01-01

145

FINAL REPORT FOR FULBRIGHT COLLEGE OF ARTS AND SCIENCES RESEARCH INNOVATION GRANT: FLOOD DYNAMICS ON THE RED RIVER OF THE NORTH, USA-CANADA  

Microsoft Academic Search

During this trip, Boss and Gosnold deployed the Knudsen Engineering, Ltd. KEL 320 B\\/P Dual Frequency Echo Sounding System from an experimental hovercraft and R\\/V Ozark Traveler in an attempt to determine the utility of this system for sub-bottom imaging of oxbow lakes and wetland areas marginal to the Red River of the North. Results of these experiments were favorable,

Stephen K. Boss

146

Water Well Record Studies of Geologic History in Indiana Including Examples of Geomorphology of Buried River Valleys, Geomorphic Expression of Earthquake Faults, and Deep Groundwater Flow Paths.  

NASA Astrophysics Data System (ADS)

The Indiana Department of Natural Resources water well record data base is used to produce maps exploring aspects of the geologic history of the state with a emphasis on East Central Indiana. This study includes the geomorphology of buried preglacial valleys, the geomorphic expression of possible fairly recent fault lines in East Central Indiana, and suggestion for the deep groundwater circulation paths. An excellent region to study geology and groundwater configuration the Midwest is East Central Indiana as there is are almost equal numbers of glacial and bedrock wells ranging over 300 feet depth. There is over 600 feet of relief on the bedrock surface with deep glacial drift in two distinctly different buried valleys, and two distinctly different till plains. The focus of this work uses over 33000 UTM located water well records from a 17250 km2, 13 county area. Over several years we have studied details of bedrock topography, bedrock and glacial geology and groundwater productivity, horizontal and vertical flow using static water level information, buried preglacial cavern systems, and applications to groundwater modeling. In the southern more maturely developed Anderson River valley there are larger numbers of deep glacial wells in many tributaries while in the north deep wells are restricted to just the deep course of the Teays River valley with less glacial productivity in the shorter less mature tributaries. To the north there many indications of a paleokarst history with sinkhole entrances on the plateaus above the Teays and outlet into the Teays tributaries. Details of the buried bedrock surface show a linear N28E trend parallel to several bedrock faults and also to recent stream valleys. Other studies by the author have shown the dominant Paleozoic bedrock fracture directions in this area to be N78E and N12W. Therefore the N28E trend is distinctly different and can be related to trends seen in active earthquake areas in northwest Ohio and southwest Indiana. The possibility of late Cenozoic seismicity related to other activity in the Midwest will be summarized. Maps comparing static water levels in shallow versus deep wells show areas of vertical downward or upward gradient which indicate three dimensional flow directions. The major deep groundwater recharge from the till plains moves to areas of upward gradient in the Wabash and Whitewater River valleys rather than other vallies on the till plains. The interpreted paths allow for discussion of ground water travel times.

Samuelson, A. C.

2007-12-01

147

Mortality associated with melarsomine dihydrochloride administration in two North American river otters (Lontra canadensis) and a red panda (Ailurus fulgens fulgens).  

PubMed

Two adult North American river otters (Lontra canadensis) and an adult red panda (Ailurus fulgens fulgens) at three separate institutions died within 22 hr after receiving single 2.5- to 2.7-mg/kg doses of melarsomine dihydrochloride administered in the epaxial musculature as a treatment for filarid nematodes. One otter had a suspected Dirofilaria immitis infection, the other had a confirmed D. lutrae infection, and the red panda had a confirmed Dirofilaria sp. infection, presumably with D. immitis. Postmortem examinations revealed similar gross lesions, although they were less severe in the red panda. The trachea and primary bronchi contained abundant foamy fluid, the lungs were mottled with areas of consolidation, and the pulmonary parenchyma exuded abundant fluid at the cut section. Histologic evaluation revealed acute pulmonary edema, which resulted in respiratory failure and death. There may have been direct pulmonary cellular toxicity of melarsomine dihydrochloride or a severe systemic anaphylactic reaction to antigens released after parasite death. An idiosyncratic drug reaction or a low therapeutic index of melarsomine probably caused the death of the three individuals. Melarsomine dihydrochloride use should be avoided in North American river otters and red pandas. PMID:12462491

Neiffer, Donald L; Klein, Edwin C; Calle, Paul P; Linn, Michael; Terrell, Scott P; Walker, Rodney L; Todd, Donna; Vice, Carol C; Marks, Steven K

2002-09-01

148

Faulted Barn  

USGS Multimedia Gallery

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

2009-01-22

149

Wave Disturbances Associated with the Red River Valley Severe Weather Outbreak of 10-11 April, 1979  

NASA Astrophysics Data System (ADS)

The purpose of this thesis is to provide an analysis of mesoscale gravity wave events during the severe weather outbreak in the Red River Valley on 10-11 April 1979. This is accomplished through an analysis of the temporal and spatial structure of the pressure surface field. The availability of three-hourly special rawinsonde data of AVE-SESAME I has made possible to relate the wavelike characteristics of the surface pressure field to the variability of the tropospheric temperature, humidity and wind fields. Three different wave events (A, B and C) were identified via spectral analysis and cross-correlation techniques. They all have similar periods, of about 3 hours, but very different phase velocities. Event A is generated in southwestern Texas, Event B is generated in central Oklahoma and Event C in southcentral Kansas; all three events are generated and propagate in the exit region of a jet streak. It is suggested that Event A is most likely related to the development of a strong divergence around 300 mb and to the ensuing mass adjustment process. Event B and C develop in a region of strong ageostrophic motion as well, but low values of the Richardson Number (Ri) suggest vertical wind shear as a likely contributor to the generation of these disturbances. Furthermore, it is suggested that low value of Ri at the critical level provide a good guiding environment for Event B and C which are detected over distances of about 400 and 600 km, respectively. Convective systems are closely linked to the waves, although not in a consistent manner: cells intensify or develop at the passage of a wave trough in event A, of a wave ridge in Event C and of a wave trough or ridge in Event B, depending on the geographic location of the cells. For all three events maximum rainfall is associated with a wave ridge with a time lag of approximately 1 hr.

Ferretti, Rossella

150

Reservoir performance in Ordovician Red River Formation, Horse Creek and South Horse Creek fields, Bowman County, North Dakota  

SciTech Connect

The contiguous Horse Creek and South Horse Creek fields produce oil from the Ordovician Red River Formation's 'D' zone (equal to the 'C' Burrowed Member). These fields produce from dolomite reservoirs at depths of about 9000 ft (3000 m) in the southern Williston basin on the northeastern flank of the southern end of the Cedar Creek anticline. Gentle ({lt}1{degree}) northeast regional dip allows oil entrapment in both areas of updip porosity pinch-out and small ({lt}2 km diameter), low-relief ({lt}30 m) structural closures. Reservoir rocks in both types of traps are burrowed dolomitized carbonate mudstones and wackestones deposited in open to restricted shelf environments. The best reservoir rocks occur where up to 25% porosity is present between completely dolomitized burrow fills. Reservoir-quality porosity is mainly intercrystalline and vuggy in finely crystalline dolomites, but even in the most porous intervals, permeability only locally exceeds 30 md. Amounts of porosity in wells producing from the 'D' zone can be used to estimate a well's ultimate oil recovery when integrated with data on structural position, thickness of porous dolomite, and the nature of the fluid saturation (best indicated by bulk volume water values). Production in the structurally trapped 'D' zone oil pools in each field, where initial water saturation was 22%, will average about 625 thousand bbl of oil/well with initially negligible water, but with increasing watercut through time. The stratigraphically trapped oil pools in the fields, where initial water saturations ranged from 32 to 66%, will average 237 thousand bbl of oil/well with higher initial watercuts, but little increase in watercut through time.

Longman, M.W. (Consulting Geologist, Lakewood, CO (United States)); Fertal, T.G. (Samuel Gary, Jr. and Associates, Inc., Denver, CO (United States)); Stell, J.R. (Snyder Oil Corp., Denver, CO (United States))

1992-04-01

151

Rivers of Red.  

ERIC Educational Resources Information Center

Describes several solutions implemented by school districts to control special-education costs. For example, expect and budget for predictable needs, provide literacy support, use more than one reading approach, consider the consequences of curriculum changes, actively teach basic study skills and organizational strategies, link resource authority…

Byrnes, MaryAnn

2003-01-01

152

Fish-Borne Zoonotic Trematodes in Cultured and Wild-Caught Freshwater Fish from the Red River Delta, Vietnam  

PubMed Central

Abstract Nam Dinh province in Red River Delta, Vietnam, is an endemic area for the human liver fluke Clonorchis sinensis, but little is known about its occurrence in the fish intermediate host in this region. A cross-sectional study was carried out to identify fish-borne zoonotic trematodes (FZT) species diversity and to estimate the prevalence and infection densities of FZT in three major types of fish: cultured species and self-recruiting species from family ponds and wild-caught species from irrigation canals in Nam Dinh province. A total of 714 wild-caught fish from canals and 829 fish from family ponds were examined for FZT infection. Only a single fish from a pond was infected with Cl. sinensis. The intestinal fluke Haplorchis pumilio was very common and found in more than 50% of fish irrespective of origin. Four other intestinal FZT species were found at low prevalence (<4.0%) except Procerovum varium, which was found in 14.4% of wild-caught fish. There was no significant difference (p?>?0.05) in FZT prevalence in cultured fish (64.3%) compared with wild-caught fish (68.9%), nor between cultured fish species (65.1%) and self-recruiting species obtained from ponds (58.1%). The prevalence of FZT in silver carp (Hypophthalmichthys molitrix) (82.7%), grass carp (Ctenopharyngodon idellus) (76.9%), and mrigal (Cirrhinus mrigala) (63.8%) was significantly higher than that in rohu (Labeo rohita) (49.1%) (p?

Ersb?ll, Annette Kjaer; Bui, Te Quang; Nguyen, Hang Thi; Murrell, Darwin; Dalsgaard, Anders

2010-01-01

153

Fish-borne zoonotic trematodes in cultured and wild-caught freshwater fish from the Red River Delta, Vietnam.  

PubMed

Nam Dinh province in Red River Delta, Vietnam, is an endemic area for the human liver fluke Clonorchis sinensis, but little is known about its occurrence in the fish intermediate host in this region. A cross-sectional study was carried out to identify fish-borne zoonotic trematodes (FZT) species diversity and to estimate the prevalence and infection densities of FZT in three major types of fish: cultured species and self-recruiting species from family ponds and wild-caught species from irrigation canals in Nam Dinh province. A total of 714 wild-caught fish from canals and 829 fish from family ponds were examined for FZT infection. Only a single fish from a pond was infected with Cl. sinensis. The intestinal fluke Haplorchis pumilio was very common and found in more than 50% of fish irrespective of origin. Four other intestinal FZT species were found at low prevalence (<4.0%) except Procerovum varium, which was found in 14.4% of wild-caught fish. There was no significant difference (p?>?0.05) in FZT prevalence in cultured fish (64.3%) compared with wild-caught fish (68.9%), nor between cultured fish species (65.1%) and self-recruiting species obtained from ponds (58.1%). The prevalence of FZT in silver carp (Hypophthalmichthys molitrix) (82.7%), grass carp (Ctenopharyngodon idellus) (76.9%), and mrigal (Cirrhinus mrigala) (63.8%) was significantly higher than that in rohu (Labeo rohita) (49.1%) (p?

Phan, Van Thi; Ersbøll, Annette Kjaer; Bui, Te Quang; Nguyen, Hang Thi; Murrell, Darwin; Dalsgaard, Anders

2010-04-06

154

Extraction faults  

NASA Astrophysics Data System (ADS)

We propose the term “extraction fault” for a planar structure that forms at the trailing edge of a discrete block when it is forced or extracted out of the surrounding material. This process results in the merging of two block-bounding faults with opposite senses of displacement. An extraction fault differs fundamentally from other faults in that its two sides have approached each other substantially in the direction perpendicular to the fault. The fault-parallel displacement may be either zero (pure extraction faults) or not (mixed extraction faults). Pure small-scale extraction faults can result from boudinage. A large-scale example may be the S-reflector of the Galicia passive continental margin which is related to rifting and continental breakup. When the strong portion of the lithosphere, i.e. the upper mantle and the lower crust, underwent necking, thermally weak mantle from below and upper crust from above collapsed into the opening gap in the rift centre and an extraction fault formed at the trailing edge of the strong lithosphere. Extraction faults are also potentially important in the exhumation of high-pressure metamorphic rocks in collisional orogens. We propose that the Combin fault on top of the eclogite-facies Zermatt-Saas ophiolites in the Penninic Alps, earlier interpreted either as a normal fault or as a thrust, is in fact an extraction fault.

Froitzheim, Nikolaus; Pleuger, Jan; Nagel, Thorsten J.

2006-08-01

155

Rivers  

NSDL National Science Digital Library

This site features pages to more than twenty NASA radar images of the world's major river systems. The image pages contain a brief description of the respective processes and setting, and are available for download. The images were created with the Spaceborne Imaging Radar-C and X-Band Synthetic Aperture Radar (SIR-C/X-SAR) as part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves allowing detailed observations at any time, regardless of weather or sunlight conditions. The multi-frequency data will be used by the international scientific community to better understand the global environment and how it is changing.

Pavlovsky, Rich

156

Millennial Slip Rate of the Longitudinal Valley Fault From River Terraces: Implications for Convergence Across the Active Suture of Eastern Taiwan  

Microsoft Academic Search

Interpreting a geomorphic analysis of fluvial terraces in the hanging-wall block of a major active fault in Taiwan by means of a structural model, we have created a model for the creation of a lithospheric suture that may have broader application. The Longitudinal Valley fault is a key element in the active tectonics of Taiwan. It is the principal structure

J. H. Shyu; K. Sieh; J. Avouac; W. Chen; Y. Chen

2005-01-01

157

Slip rates on the Chelungpu and Chushiang thrust faults inferred from a deformed strath terrace along the Dungpuna river, west central Taiwan  

Microsoft Academic Search

The Chelungpu fault produced the September 1999 Mw = 7.6 Chi-Chi earthquake, central Taiwan. The shortening rate accommodated by this structure, integrated over several seismic cycles, and its contribution to crustal shortening across the Taiwanese range have remained unresolved. To address the issues, we focus our study on the Chelungpu and Chushiang thrust faults within the southernmost portion of the

Martine Simoes; Jean Philippe Avouac; Yue-Gau Chen

2007-01-01

158

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

Microsoft Academic Search

The Cathedral Rapids fault extends ~40 km between the Tok and Robertson River valleys and is the easternmost fault in a series of active south-dipping imbricate thrust faults which bound the northern flank of the Alaska Range. Collectively, these faults accommodate a component of convergence transferred north of the Denali fault and related to the westward (counterclockwise) rotation of the

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

2010-01-01

159

Geometry and scaling relations of a population of very small rift-related normal faults  

Microsoft Academic Search

Exceptionally well exposed normal faults within the Solite Quarry of the Dan River rift basin range in length from a few millimetres to a few metres and are possibly the smallest visible faults studied to date. Displacement is greatest at or near the center of isolated faults and decreases toward the fault tips. Relay structures form between closely overlapping faults.

Roy W. Schlische; Scott S. Young; Rolf V. Ackermann; Anupma Gupta

1996-01-01

160

A Geologist's Perspective on the Red River of the North: History, Geography, and Planning\\/Management Issues  

Microsoft Academic Search

In 1974, Arndt and Moran published a geologic report providing baseline information to guide planning in the region of Fargo, North Dakota, and adjacent Moorhead, Minnesota. To most inhabitants of this region, this report today remains obscure. But to regional geologists, Arndt and Moran's report represents a pioneering perspective on knowledgeable, geologic-centered planning within an urban setting in the Red

Donald P. Schwert

161

Species composition, diversity, biomass, and chlorophyll of periphyton in greasy creek, red rock creek, and the Arkansas River, Oklahoma  

Microsoft Academic Search

Seventy-nine taxa of periphyton were collected on Plexiglas plates at seven stations in the three streams between March, 1975, and February, 1976. More taxa and lower densities were generally observed at the upstream stations in the creeks than at the downstream stations resulting in greater species diversity values at the upstream stations. Species diversity was generally lower in the river

Jerry Wilhm; James Cooper; Harold Namminga

1978-01-01

162

Comparative Environmental Toxicology Assessment of White and Red Phosphorous Munitions, Eagle River Flats Firing Range, Ft. Richardson, Alaska.  

National Technical Information Service (NTIS)

Eagle River Flats Firing Range is used as an impact area by troops training at Ft. Richardson, AK. Firing of white phosphorous munitions was suspended in February 1990 because of mortality to migratory waterfowl. The Commander of Ft. Richardson is seeking...

M. S. Johnson W. S. Eck

2009-01-01

163

Genetic diversity among red swamp crayfish (Procambarus clarkii) populations in the middle and lower reaches of the Yangtze River based on AFLP markers.  

PubMed

The red swamp crayfish has become one of the most important freshwater aquaculture species in China. At present, although it is widely distributed in the middle and lower reaches of the Yangze River basin, little is known about its population genetics and geographic distribution in China. We estimated the genetic diversity among 6 crayfish populations from 4 lakes (Hongze Lake, Poyang Lake, Dongting Lake, and Yue Lake) using AFLPs. A total of 129 loci were generated with 5 EcoRI-MseI primer combinations and scored as binary data in 139 individuals. These data were analyzed by cluster methods with the NTSYSpc software package. The 6 populations were separated into 3 major clusters by principal coordinate analysis and cluster analysis. Among the 6 populations, the highest gene diversity was found within the Nanjing population. Analysis of molecular variance demonstrated that most variation occurred within populations (91.20%). The estimated average GST value across all loci was 0.4186, suggesting (very) low gene flow among the different localities. We conclude that there is high genetic differentiation among crayfish in the middle and lower reaches of the Yangze River. This information will help in the selection of high-quality individuals for artificial reproduction. PMID:23546963

Zhu, B F; Huang, Y; Dai, Y G; Bi, C W; Hu, C Y

2013-03-13

164

Tectonics and Landforms: Types of Faults  

NSDL National Science Digital Library

This resource offers animations depicting the defining motions of five different types of faults. Also included is a data visualization showing the geographic patterns of faults and earthquakes, and a documentary video which discusses a series of great earthquakes that occurred between 1811 - 1812 and includes an animation of how the Mississippi River Valley was created.

Ritter, Michael

165

Myrionecta Rubra Population Genetic Diversity and Its Cryptophyte Chloroplast Specificity in Recurrent Red Tides in the Columbia River Estuary  

SciTech Connect

For at least a decade, annually recurring blooms of the photosynthetic ciliate, Myrionecta rubra have been observed in the Columbia River estuary in late summer. In an effort to understand the dynamics of these blooms, we investigated the genetic variability of M. rubra and its cryptophyte plastids within three large estuarine blooms formed in consecutive years (2007-2009), and conducted a broader spatial survey along the coasts of Oregon/Washington. Analysis of the ‘18S-28S’ sequences specific for Mesodiniidae uncovered at least 7 variants of M. rubra within the Columbia River coastal margin in spring and summer, but only one of these M. rubra variants was implicated in estuary bloom formation. Using a multigene approach, we show that the bloom-forming variant of M. rubra appears to harbor the same cryptophyte chloroplast in recurring blooms. Analyses of chloroplast 16S rRNA, cryptophyte RuBisCO and Photosystem II D2 genes together suggest that the plastid is derived from Teleaulax amphioxeia. Free-living cells of this species and of other cryptophytes were practically absent from the bloom patches in the estuary main channels based on 18S rDNA sequence analyses. The respectively low and high proportions of T. amphioxeia nuclei and chloroplasts signals found in the M. rubra bloom of the Columbia River estuary in successive years supports the notion of a transient association between T. amphioxeia and the bloom-forming M. rubra variant, with loss of cryptophyte nuclei. The genetic variability of M. rubra uncovered here is relevant to the controversy in the literature regarding the cryptophyte /M. rubra association.

Herfort, Lydie; Peterson, Tawnya D.; McCue, Lee Ann; Crump, Byron C.; Prahl, Fredrick G.; Baptista, Antonio M.; Campbell, Victoria; Warnick, Rachel; Selby, Mikaela; Roegner, G. Curtis; Zuber, Peter A.

2011-01-04

166

Surface complexation modeling of groundwater arsenic mobility: Results of a forced gradient experiment in a Red River flood plain aquifer, Vietnam  

NASA Astrophysics Data System (ADS)

Three surface complexation models (SCMs) developed for, respectively, ferrihydrite, goethite and sorption data for a Pleistocene oxidized aquifer sediment from Bangladesh were used to explore the effect of multicomponent adsorption processes on As mobility in a reduced Holocene floodplain aquifer along the Red River, Vietnam. The SCMs for ferrihydrite and goethite yielded very different results. The ferrihydrite SCM favors As(III) over As(V) and has carbonate and silica species as the main competitors for surface sites. In contrast, the goethite SCM has a greater affinity for As(V) over As(III) while PO43- and Fe(II) form the predominant surface species. The SCM for Pleistocene aquifer sediment resembles most the goethite SCM but shows more Si sorption. Compiled As(III) adsorption data for Holocene sediment was also well described by the SCM determined for Pleistocene aquifer sediment, suggesting a comparable As(III) affinity of Holocene and Pleistocene aquifer sediments. A forced gradient field experiment was conducted in a bank aquifer adjacent to a tributary channel to the Red River, and the passage in the aquifer of mixed groundwater containing up to 74% channel water was observed. The concentrations of As (<0.013 ?M) and major ions in the channel water are low compared to those in the pristine groundwater in the adjacent bank aquifer, which had an As concentration of ˜3 ?M. Calculations for conservative mixing of channel and groundwater could explain the observed variation in concentration for most elements. However, the mixed waters did contain an excess of As(III), PO43- and Si which is attributed to desorption from the aquifer sediment. The three SCMs were tested on their ability to model the desorption of As(III), PO43- and Si. Qualitatively, the ferrihydrite SCM correctly predicts desorption for As(III) but for Si and PO43- it predicts an increased adsorption instead of desorption. The goethite SCM correctly predicts desorption of both As(III) and PO43- but failed in the prediction of Si desorption. These results indicate that the prediction of As mobility, by using SCMs for synthetic Fe-oxides, will be strongly dependent on the model chosen. The SCM based on the Pleistocene aquifer sediment predicts the desorption of As(III), PO43- and Si quite superiorly, as compared to the SCMs for ferrihydrite and goethite, even though Si desorption is still somewhat under-predicted. The observation that a SCM calibrated on a different sediment can predict our field results so well suggests that sediment based SCMs may be a feasible way to model multi-component adsorption in aquifers.

Jessen, Søren; Postma, Dieke; Larsen, Flemming; Nhan, Pham Quy; Hoa, Le Quynh; Trang, Pham Thi Kim; Long, Tran Vu; Viet, Pham Hung; Jakobsen, Rasmus

2012-12-01

167

The use of the red swamp crayfish (Procambarus clarkii, Girard) as indicator of the bioavailability of heavy metals in environmental monitoring in the River Guadiamar (SW, Spain).  

PubMed

A translocation experiment of red swamp crayfish (Procambarus clarkii) to different sites located in the River Guadiamar was performed in order to assess the ability of this species as bioindicator of heavy metal and metalloid contamination. Crayfish were placed in cages and exposed to polluted environment during either 6 or 12days in the three sites with different concentration of contaminants. Their tissues (exoskeleton+gills, hepatopancreas and abdominal muscle) were dissected and analysed by ICP-MS to assess for concentration of Cd, Cu, Zn, Pb and As. Both exposure times result in significant bioaccumulation of some metals in crayfish tissues as compared to their concentration in the environment. According to overall metal concentration, crayfish tissues rank as follows: hepatopancreas/viscera>exoskeleton/gills>abdominal muscle. Essential metals for crayfish metabolism (Cu and Zn) are always found in high concentrations independently of their quantities in the environment because of the ability of crayfish to manipulate their levels for their own metabolic profit. Metals not involved in crayfish metabolism (Cd, Pb, As) tend to increase with increasing concentration in the surrounding environment and with longer exposure times. Thus crayfish could be used as bioindicator of these pollutants because their dose- and time-dependent accumulation may be reflective of the levels of non-essential metals present in contaminated wetlands. Future guidelines in plans for monitoring contamination on polluted Mediterranean rivers and wetlands should take into account the implementation of the incubation of crayfish during 6days and their subsequent analyses of metal contents, as a routine. PMID:16546239

Alcorlo, Paloma; Otero, Marina; Crehuet, María; Baltanás, Angel; Montes, Carlos

2006-03-06

168

Fault mechanics  

SciTech Connect

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

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

1991-01-01

169

Evaluation of drainage-area ratio method used to estimate streamflow for the Red River of the North Basin, North Dakota and Minnesota  

USGS Publications Warehouse

The drainage-area ratio method commonly is used to estimate streamflow for sites where no streamflow data were collected. To evaluate the validity of the drainage-area ratio method and to determine if an improved method could be developed to estimate streamflow, a multiple-regression technique was used to determine if drainage area, main channel slope, and precipitation were significant variables for estimating streamflow in the Red River of the North Basin. A separate regression analysis was performed for streamflow for each of three seasons-- winter, spring, and summer. Drainage area and summer precipitation were the most significant variables. However, the regression equations generally overestimated streamflows for North Dakota stations and underestimated streamflows for Minnesota stations. To correct the bias in the residuals for the two groups of stations, indicator variables were included to allow both the intercept and the coefficient for the logarithm of drainage area to depend on the group. Drainage area was the only significant variable in the revised regression equations. The exponents for the drainage-area ratio were 0.85 for the winter season, 0.91 for the spring season, and 1.02 for the summer season.

Emerson, Douglas G.; Vecchia, Aldo V.; Dahl, Ann L.

2005-01-01

170

A new species of Rhipicephalus (Acari: Ixodidae), a parasite of red river hogs and domestic pigs in the Democratic Republic of Congo.  

PubMed

A new tick species belonging to the genus Rhipicephalus Koch, 1844 (Acari: Ixodidae), namely, Rhipicephalus congolensis n. sp., is described. Males and females of this species are similar to those of Rhipicephalus complanatus Neumann, 1911 and Rhipicephalus planus Neumann, 1907, but it can be distinguished from them by a pattern of dense medium-sized punctations on the conscutum and scutum. Males of R. congolensis may be distinguished by the following characters: posterior half of the marginal groove deep with a sharp outer edge; anterior portion of the groove shallow with rounded edges; posteromedian groove distinct, long, and deep; adanal plates broadly sickle-shaped; bluntly pointed posteromedian spur on coxa I; and posterolateral spur on coxa I slightly longer or subequal to posteromedian spur. Females of R. congolensis may be distinguished by the following characters: outer edge of cervical grooves smooth and not clearly defined either by slope or punctations; genital aperture broad, bowl-shaped, and tripartite in appearance, with central flap flanked on either side by an oval depression; and posteromedian spur on coxa I tapering to its apex. R. congolensis is known only from the Democratic Republic of Congo, where the adults were collected from red river hogs, Potamochoerus porcus (L.), and domestic pigs, Sus scrofa (L.), within the dense equatorial forest in the districts of Equateur and Tshuapa, in the province of Equateur. PMID:23802441

Apanaskevich, Dmitry A; Horak, Ivan G; Mulumba-Mfumu, Leopold K

2013-05-01

171

Technical and economic feasibility of salt-gradient solar ponds at the Truscott Brine Lake of the Red River Chloride Control Project. A report to the House-Senate Committee on Appropriations of the Ninety-Seventh Congress  

SciTech Connect

The Truscott Brine Lake is being constructed to impound highly brackish water from a number of sources which would normally flow into the Wichita River, a tributary of the Red River in Knox County, Texas. A 35.4-km (22-mile) pipeline is being constructed to carry the brines from their primary source to the Truscott Brine Lake site. The reservoir is designed to contain 100 years of brine emissions from three chloride emission areas in the Wichita River Basin. The solar ponds and power generating facilities would be located in the Bluff Creek Arm of Truscott Brine Lake. The Truscott Brine Lake study includes: survey of suitability of Truscott Lake site, review of solar pond technology, preconceptual design of solar salt pond power plant, and economic evaluation.

Not Available

1982-09-01

172

Late Quaternary fault activity in the Western Carpathians: evidence from the Vikartovce Fault (Slovakia)  

NASA Astrophysics Data System (ADS)

The Cenozoic structure of the Western Carpathians is strongly controlled by faults. The E-W striking Vikartovce fault is one of the most distinctive dislocations in the region, evident by its geological structure and terrain morphology. This feature has been assumed to be a Quaternary reactivated fault according to many attributes such as its perfect linearity, faceted slopes, the distribution of travertines along the fault, and also its apparent prominent influence on the drainage network. The neotectonic character of the fault is documented herein by morphotectonic studies, longitudinal and transverse valley profile analyses, terrace system analysis, and mountain front sinuosity. Late Pleistocene activity of the Vikartovce fault is now proven by luminescence dating of fault-cut and uplifted alluvial sediments, presently located on the crest of the tilted block. These sediments must slightly pre-date the age of river redirection. Considering the results of both luminescence dating and palynological analyses, the change of river course probably occurred during the final phase of the Riss Glaciation (135 ± 14 ka). The normal displacement along the fault during the Late Quaternary has been estimated to about 105-135 m, resulting in an average slip rate of at least 0.8-1.0 mm · yr-1. The present results identify the Vikartovce fault as one of the youngest active faults in the Central Western Carpathians.

Vojtko, Rastislav; Marko, František; Preusser, Frank; Madarás, Ján; Ková?ová, Marianna

2011-12-01

173

Automated distribution fault locating system  

SciTech Connect

An automated fault locating system (FLS) was designed and implemented for the Colorado River Agency (CRA) 12.5/7.2-kV distribution system. This FLS was integrated into the supervisory control and data acquisition (SCADA) system which was installed at a hydropower plant. This FLS offers several benefits to the CRA distribution system. These benefits include reduced outage time, help in locating momentary faults, enhanced safety to the line crews, provide notification of an outage without receiving calls from the consumer, and decreased overtime.

Hager, G.E. [Electrical Systems Consultants Inc., Fort Collins, CO (United States); Medicine Bear, R.N. [City of Aztec, NM (United States); Baum, A.S. [Scipar Inc., Buffalo, NY (United States)

1996-05-01

174

The Starr fault system of southeastern Ohio  

SciTech Connect

The Starr fault system is a series of east-west-trending faults located in southeastern Ohio. This fault system was discovered by mapping the anomalous sedimentary sequence of the [open quotes]Big Lime[close quotes]. The Big Lime is a driller's term for the stratigraphic section that includes the Lower Devonian Onondaga through Middle Silurian Lockport formations. The use of trend-surface analysis identified the probable fault orientation, which was then verified by seismic. The system is a series of high-angle faults, originating in the Precambrian, that occur along a narrow corridor traversing several townships. Analysis of the sedimentary section preserved by faulting indicates fault movement after the deposition of the Bass Island Formation, which was followed by a regional unconformity that removed the Bass Islands and a part of the upper Salina Formation. The Onondaga subsequently was deposited, masking fault movement evidence in the shallower formations. Some minor movement occurred later, as evidenced by the expansion in the Devonian shale sequence. The geometry of the fault system and other data suggest a pattern similar to the Albio-Scipio field of southern Michigan. A group of wells were drilled to test the Ordovician Trenton and Black River formations to determine the existence of secondary dolomite, which could be a potential reservoir. Secondary dolomite was encountered, but no commercial hydrocarbons were found in either the Trenton or Black River. Other formations produced hydrocarbons and water from fractured zones that were not known for this behavior. Other probable fault systems in southern Ohio, identified by using the same mapping techniques, may provide deeper targets for future drilling.

Brannock, M.C. (Qauker State Corp., Belpre, OH (United States))

1993-08-01

175

CMOS Bridging Fault Detection  

Microsoft Academic Search

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

Thomas M. Storey; Wojciech Maly

1990-01-01

176

Release and establishment of fire ant parasitic flies, Pseudacteon curvatus and Pseudacteon tricuspis (Diptera: Phoridae) in Denton and Red River counties in 2008  

Microsoft Academic Search

Biological control, combined with conventional chemical methods, are now being used to manage the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae) in the United States. Classical biological control has the potential to effectively control pest populations and in some cases it is more effective than conventional chemical methods. There are many natural enemies of the red imported fire

Kimberly Schofield; Lynn Golden

177

Extirpation of Red Shiner in Direct Tributaries of Lake Texoma (Oklahoma-Texas): A Cautionary Case History from a Fragmented River-Reservoir System  

Microsoft Academic Search

The effects of reservoirs on composition of fish assemblages are well documented in and downstream of reservoirs but are less well known upstream, especially in small tributaries. Here we report that a historically very abundant native minnow species (red shiner Cyprinella lutrensis) has been extirpated from several direct tributaries of Lake Texoma, a large impoundment of the Red and Washita

William J. Matthews; Edie Marsh-Matthews

2007-01-01

178

Geometry of miocene extensional deformation, lower Colorado River Region, Southeastern California and Southwestern Arizona: Evidence for the presence of a regional low-angle normal fault  

NASA Astrophysics Data System (ADS)

The geometry of Miocene extensional deformation, which changes along a 120 km-long, northeast-trending transect from the southestern Chocolate Mountains, southeastern California, to the Trigo and southern Dome Rock Mountains, southwestern Arizona is discussed. Based upon regional differences in the structural response to extension and estimated extensional strain, the transet can be divided into three northwesterly-trending structural domains. From southwest to northeast, these domains are: (1) southestern Chocolate-southernmost Trigo Mountains; (2) central to northern Trigo Mountains; and (3) Trigo Peaks-southern Dome Rock Mountains. All structures formed during the deformation are brittle in style; fault rocks are composed of gouge, cohesive gouge, and local microbreccia. In each structural domain, exposed lithologic units are composed of Mesozoic crystalline rocks unconformably overlain by Oligocene to Early Miocene volcanic and minor interbedded sedimentary rocks. Breccia, conglomerate, and sandstone deposited synchronously with regional extension locally overlie the volcanic rocks. Extensional deformation largely postdated the main phase of volcanic activity, but rare rhyolitic tuff and flows interbedded with the syndeformational clastic rocks suggest that deformation began during the waning stages of valcanism. K-Ar isotopic ages indicate that deformation occurred in Miocene time, between about 22 and m.y. ago.

Tosdal, R. M.; Sherrod, D. R.

179

Alteration of fault development on the accumulated oil geochemical features  

Microsoft Academic Search

The geochemical characteristics of crude oils and reservoir bed extracts in a well drilled in Pearl River Mouth Basin, South China Sea, were investigated in detail. The trap in which a well was drilled was cut by a sub-east-west direction normal fault. According to the seismic section study, the fault has been activated three times, which altered the oil geochemical

Fu Jiamo; Pei Cunmin; Sheng Guoying; Chen Sizhong

1994-01-01

180

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

Microsoft Academic Search

During the devastating earthquake of 13 May 1995, in the Kozani-Grevena area (Western Macedonia, Greece), many surface ruptures formed in the epicentral area. Most of these fractures were due to faulting, but some were secondary ground ruptures and landslides.Geological field work in the area has shown that the Aliakmon river neotectonic fault consists of several (three or more) fault strands:

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

1998-01-01

181

Slip localization on the southern Alpine Fault, New Zealand  

NASA Astrophysics Data System (ADS)

of a detailed field study of the southern onshore portion of New Zealand's Alpine Fault reveal that for 75 km along-strike, dextral-normal slip on this long-lived structure is highly localized in phyllosilicate-rich fault core gouges and along their contact with more competent rocks. At three localities (Martyr River, McKenzie Creek, and Hokuri Creek), we document complete cross sections through the fault. New 40Ar/39Ar dates on mylonites, combined with microstructural and mechanical data on phyllosilicate-rich fault core gouges show that modern slip is localized onto a single, steeply dipping 1 to 12 m-thick fault core composed of impermeable (k = 10-20 to 10-22 m2), frictionally weak (?s = 0.12-0.37), velocity-strengthening, illite-chlorite, and saponite-chlorite-lizardite fault gouges. Fault core materials are (1) comparable to those of other major weak-cored faults (e.g., San Andreas Fault) and (2) most compatible with fault creep, despite paleoseismic evidence of quasiperiodic large magnitude earthquakes (Mw > 7) on this portion of the Alpine Fault. We conclude that frictional properties of gouges at the surface do not characterize the overall seismogenic behavior of the southern Alpine Fault.

Barth, N. C.; Boulton, C.; Carpenter, B. M.; Batt, G. E.; Toy, V. G.

2013-06-01

182

Fault slip distribution and fault roughness  

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

183

Transition Fault Simulation  

Microsoft Academic Search

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

John Waicukauski; Eric Lindbloom; Barry Rosen; Vijay Iyengar

1987-01-01

184

A dynamic fault tree  

Microsoft Academic Search

The fault tree analysis is a widely used method for evaluation of systems reliability and nuclear power plants safety. This paper presents a new method, which represents extension of the classic fault tree with the time requirements. The dynamic fault tree offers a range of risk informed applications. The results show that application of dynamic fault tree may reduce the

Marko ?epin; Borut Mavko

2002-01-01

185

Fault zone fabric and fault weakness.  

PubMed

Geological and geophysical evidence suggests that some crustal faults are weak compared to laboratory measurements of frictional strength. Explanations for fault weakness include the presence of weak minerals, high fluid pressures within the fault core and dynamic processes such as normal stress reduction, acoustic fluidization or extreme weakening at high slip velocity. Dynamic weakening mechanisms can explain some observations; however, creep and aseismic slip are thought to occur on weak faults, and quasi-static weakening mechanisms are required to initiate frictional slip on mis-oriented faults, at high angles to the tectonic stress field. Moreover, the maintenance of high fluid pressures requires specialized conditions and weak mineral phases are not present in sufficient abundance to satisfy weak fault models, so weak faults remain largely unexplained. Here we provide laboratory evidence for a brittle, frictional weakening mechanism based on common fault zone fabrics. We report on the frictional strength of intact fault rocks sheared in their in situ geometry. Samples with well-developed foliation are extremely weak compared to their powdered equivalents. Micro- and nano-structural studies show that frictional sliding occurs along very fine-grained foliations composed of phyllosilicates (talc and smectite). When the same rocks are powdered, frictional strength is high, consistent with cataclastic processes. Our data show that fault weakness can occur in cases where weak mineral phases constitute only a small percentage of the total fault rock and that low friction results from slip on a network of weak phyllosilicate-rich surfaces that define the rock fabric. The widespread documentation of foliated fault rocks along mature faults in different tectonic settings and from many different protoliths suggests that this mechanism could be a viable explanation for fault weakening in the brittle crust. PMID:20016599

Collettini, Cristiano; Niemeijer, André; Viti, Cecilia; Marone, Chris

2009-12-17

186

Fault analysis based on fault reporting in JSP software development  

Microsoft Academic Search

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

Yukio MOHRI; T. Kikuno

1991-01-01

187

Behavioral Fault Simulation in VHDL  

Microsoft Academic Search

This paper presents two tools which facilitate the fault simulation of behavioral models described using VHDL. The first tool is the Behavioral Fault Mapper (BFM). The BFM algorithm accepts a fault-free VHDL model and a fault list of N faults from which it produces N faulty models. The process of mapping the faults in the fault list onto copies of

P. C. Ward; James R. Armstrong

1990-01-01

188

Mountain front migration and drainage captures related to fault segment linkage and growth: The Polopos transpressive fault zone (southeastern Betics, SE Spain)  

NASA Astrophysics Data System (ADS)

The Polopos E-W- to ESE-WNW-oriented dextral-reverse fault zone is formed by the North Alhamilla reverse fault and the North and South Gafarillos dextral faults. It is a conjugate fault system of the sinistral NNE-SSW Palomares fault zone, active from the late most Tortonian (?7 Ma) up to the late Pleistocene (?70 ky) in the southeastern Betics. The helicoidal geometry of the fault zone permits to shift SE-directed movement along the South Cabrera reverse fault to NW-directed shortening along the North Alhamilla reverse fault via vertical Gafarillos fault segments, in between. Since the Messinian, fault activity migrated southwards forming the South Gafarillos fault and displacing the active fault-related mountain-front from the north to the south of Sierra de Polopos; whilst recent activity of the North Alhamilla reverse fault migrated westwards. The Polopos fault zone determined the differential uplift between the Sierra Alhamilla and the Tabernas-Sorbas basin promoting the middle Pleistocene capture that occurred in the southern margin of the Sorbas basin. Continued tectonic uplift of the Sierra Alhamilla-Polopos and Cabrera anticlinoria and local subsidence associated to the Palomares fault zone in the Vera basin promoted the headward erosion of the Aguas river drainage that captured the Sorbas basin during the late Pleistocene.

Giaconia, Flavio; Booth-Rea, Guillermo; Martínez-Martínez, José Miguel; Azañón, José Miguel; Pérez-Romero, Joaquín; Villegas, Irene

2013-01-01

189

33 CFR 125.06 - Western rivers.  

Code of Federal Regulations, 2013 CFR

...western rivers as used in the regulations in this subchapter shall include only the Red River of the North, the Mississippi River and its tributaries above the Huey P. Long Bridge, and that part of the Atchafalaya River above its junction...

2013-07-01

190

Fault tree handbook  

SciTech Connect

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.

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

1981-01-01

191

Effects of Various Levee Alignments and Grades on 1973 and Project Design Flowlines in the Red-Ouachita-Black River Basin.  

National Technical Information Service (NTIS)

This study was conducted on the Vicksburg-to-Baton Rouge reach of the Mississippi Basin Model, a fixed-bed model of the Mississippi River and its tributaries built to a horizontal scale of 1 to 2,000 and a vertical scale of 1 to 100. The tests were conduc...

J. E. Foster J. V. Allen J. E. Glover

1984-01-01

192

Active faulting near Taupo  

NASA Astrophysics Data System (ADS)

The only confirmed fault displacement in New Zealand since that accompanying the 1968 Inangahua Earthquake was observed on June 23 and 24, 1983, 4 km west of Taupo in the Taupo Volcanic Zone, central North Island (Figure 1). Normal displacement occurred on the late Quaternary Kaiapo fault, previously active in 1922, when almost 1 m of normal fault displacement was observed [Grange, 1932], The Kaiapo Fault is one of a number of north-east trending normal faults that constitute the active Taupo Fault Belt [Grindley, 1961], Current extension rates up to 7 mm per year have been calculated from geodetic observations [Sissons, 1979] across the northern part of the Taupo Volcanic Zone.

Hull, Alan G.; Grindley, George W.

193

Field and Laboratory Data From an Earthquake History Study of Scarps of the Lake Creek-Boundary Creek Fault Between the Elwha River and Siebert Creek, Clallam County, Washington  

USGS Publications Warehouse

Fault scarps recently discovered on Airborne Laser Swath Mapping (ALSM; also known as LiDAR) imagery show Holocene movement on the Lake Creek-Boundary Creek fault on the north flank of the Olympic Mountains of northwestern Washington State. Such recent movement suggests the fault is a potential source of large earthquakes. As part of the effort to assess seismic hazard in the Puget Sound region, we map scarps on ALSM imagery and show primary field and laboratory data from backhoe trenches across scarps that are being used to develop a latest Pleistocene and Holocene history of large earthquakes on the fault. Although some scarp segments 0.5-2 km long along the fault are remarkably straight and distinct on shaded ASLM imagery, most scarps displace the ground surface <1 m, and, therefore, are difficult to locate in dense brush and forest. We are confident of a surface-faulting or folding origin and a latest Pleistocene to Holocene age only for scarps between Lake Aldwell and the easternmost fork of Siebert Creek, a distance of 22 km. Stratigraphy in five trenches at four sites help determine the history of surface-deforming earthquakes since glacier recession and alluvial deposition 11-17 ka. Although the trend and plunge of indicators of fault slip were measured only in the weathered basalt exposed in one trench, upward-splaying fault patterns and inconsistent displacement of successive beds along faults in three of the five trenches suggest significant lateral as well as vertical slip during the surface-faulting or folding earthquakes that produced the scarps. Radiocarbon ages on fragments of wood charcoal from two wedges of scarp-derived colluvium in a graben-fault trench suggest two surface-faulting earthquakes between 2,000 and 700 years ago. The three youngest of nine radiocarbon ages on charcoal fragments from probable scarp-derived colluvum in a fold-scarp trench 1.2 km to the west suggest a possible earlier surface-faulting earthquake less than 5,000 years ago.

Nelson, Alan R.; Personius, Stephen F.; Buck, Jason; Bradley, Lee-Ann; Wells, Ray E.; Schermer, Elizabeth R.

2007-01-01

194

Red Bull  

Microsoft Academic Search

The Red Bull case describes the history of the Red Bull brand and how the company stimulated and harnessed word-of-mouth to build a new product category (functional energy drinks) and brand franchise. The case concludes by asking the reader to consider how Red Bull should react to competitive challenges in the U.S. The Red Bull case was written to enable

Paul Farris; Richard Johnson

195

Style of the surface deformation by the 1999 Chichi earthquake at the central segment of Chelungpu fault, Taiwan, with special reference to the presence of the main and subsidiary faults and their progressive deformation in the Tsauton area  

NASA Astrophysics Data System (ADS)

We describe the style of surface deformation in the 1999 Chichi earthquake in the central segment of the Chelungpu Fault. The study covers the Kung-fu village, north of Han River, to the south of Tsauton area. A characteristic style of the surface deformation is a convex scarp in profile and sinuous plan view, due to the low angle thrust fault. Two subparallel faults, including the west facing Tsauton West fault, and the east facing Tsauton East fault, limit the western and eastern margin of the Tsauton terraced area. The Tsauton West fault is the continuation of the main Chelungpu fault and the Tsauton East fault is located about 2 km apart. Both faults record larger amounts of vertical displacement on the older terraces. The 1999 surface rupture occurred exactly on a pre-existing fault scarp of the Tsauton West and East faults. Thus, repeated activities of these two faults during the Holocene, possibly since the late Quaternary, are confirmed. The amount of vertical offset of the Tsauton East fault is smaller, and about 40 50% of that of the Tsauton West fault for the pre-existing fault. This indicates that the Tsauton East fault is a subsidiary fault and moved together with the main fault, but accommodated less amount.

Ota, Y.; Watanabe, M.; Suzuki, Y.; Yanagida, M.; Miyawaki, A.; Sawa, H.

2007-11-01

196

Impact of Urban Pollution from the Hanoi Area on Benthic Diatom Communities Collected from the Red, Nhue and Tolich Rivers (Vietnam)  

Microsoft Academic Search

The effects of urban pollution from Hanoi city on the benthic diatom communities of the Nhue–Tolich river system were studied\\u000a during the 2003 dry season. Benthic diatoms were allowed to grow on glass slides suspended in the water flow for 4 weeks.\\u000a To reveal the relationship between water quality and diatom communities, Canonical correspondence analysis (CCA) was used\\u000a on data concerning

Thi Thuy Duong; Michel Coste; Agnès Feurtet-Mazel; Dinh Kim Dang; Caroline Gold; Young Seuk Park; Alain Boudou

2006-01-01

197

Complex Faulting within the New Madrid Seismic Zone  

NASA Astrophysics Data System (ADS)

Relative relocations derived using double-difference tomography techniques reveal a complex sequence of faulting within the New Madrid Seismic Zone (NMSZ) and upper Mississippi Embayment. The majority of NMSZ seismicity recorded over the last 30 years occurs along four limbs: 1) a NE-SW trending dextral strike-slip fault, termed the Axial fault, coincident with the central valley of the Cambrian Reelfoot Rift system; 2) the SE-NW trending Reelfoot thrust fault; 3) a E-W trending left lateral strike-slip fault extending off of the northern terminus of the Reelfoot fault, here termed New Madrid west; and 4) a NE-SW dextral strike-slip fault also extending off of the northern terminus of the Reelfoot fault, here termed New Madrid north. Each of these segments is thought to have ruptured during the 1811-1812 large earthquake sequence. A fifth segment, the Bootheel lineament, is marked by 1811-1812 related liquefaction features but appears largely aseismic, though we suggest there are at least five events in the catalog associated with this feature. Geological and geophysical evidence across the embayment suggests that the region is crossed by additional faults at shallow depths (<1-2 km), while seismicity is generally confined to the 3-20 km depth range. Here we present relative relocations derived using catalog and waveform cross-correlation differential times of the 1989-1992 local PANDA network and the 1995-2010 Cooperative New Madrid Seismic Network. We show that the four known seismic lineations exhibit internal complexity. For example, New Madrid north is composed of two parallel faults rather then a single fault, and seismicity associated with the Axial lineation exhibits temporal changes along strike and becomes spatially more diffuse south of the Axial fault/Bootheel lineament intersection. Seismicity along the southern Reelfoot fault does not define a dipping plane consistent with thrust faulting, unlike the northern Reelfoot fault, and is associated with anomalously low P wave velocities. Swarm activity along the southern portion of the Reelfoot fault and near the northern portion of the Reelfoot fault terminus may be related to fault intersections within this complicated transpressional system. Recent reflection data of the upper 1 km imaged along the Mississippi River indicate that both the north termini of the Reelfoot and Axial faults are characterized by splay faulting, while at depth microseismicity is planar. Absolute and relative error will be assessed by computing locations within two 3D P and S wave velocity models of the study area, using finite difference and pseudo-bending ray tracing approaches, and jack-knife approaches to test dependence on network geometry.

Deshon, H. R.; Powell, C. A.; Magnani, M.; Bisrat, S. T.

2010-12-01

198

Bookshelf faulting in Nicaragua  

Microsoft Academic Search

Oblique subduction at a high rate of convergence along much of the Middle America Trench results in northwest-directed trench-parallel block motion. Accommodation of this motion along northwest-striking dextral strike-slip faults has been postulated; however, in Nicaragua such faults are not well developed. We suggest instead that this motion is accommodated by bookshelf faulting that includes northeast-striking left-lateral faults. We present

Peter C. La Femina; T. H. Dixon; W. Strauch

2002-01-01

199

Mechanics of discontinuous faults  

Microsoft Academic Search

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

P. Segall; D. D. Pollard

1980-01-01

200

Active Faulting in Idaho  

NSDL National Science Digital Library

This lesson introduces students to faulting from the Quaternary Period and the Holocene Epoch in the State of Idaho. They will examine a map showing the distribution of these faults and answer questions concerning groundwater circulation and earthquake potential, and determine which geologic province has the most neotectonically active faults (15,000 years or younger).

201

The presence, characteristics and earthquake implications of the St. Lawrence fault zone within and near Lake Ontario (Canada–USA)  

Microsoft Academic Search

Questions persist concerning the earthquake potential of the populous and industrial Lake Ontario (Canada–USA) area. Pertinent to those questions is whether the major fault zone that extends along the St. Lawrence River valley, herein named the St. Lawrence fault zone, continues upstream along the St. Lawrence River valley at least as far as Lake Ontario or terminates near Cornwall (Ontario,

J. L Wallach

2002-01-01

202

Active Faulting Along the Ulakhan Fault, Seimchan-Buyunda Basin, Northeast Russia  

NASA Astrophysics Data System (ADS)

The Seimchan-Buyunda basin is a topographically flat, 30 x 100 km region that is located along the eastern margin of the Ulakhan fault in northeast Russia. The Ulakhan fault roughly parallels the accretionary boundary between the Kolyma-Omolon superterrane and Siberian craton and delineates the modern plate boundary between the Okhotsk block and the North American plate proper. The subsidence history of the Seimchan basin and scale of seismic activity of the Ulakhan fault remain widely speculative due largely to a lack of detail study in this region. However, preliminary evidence suggests that active subsidence in the basin is being driven by modern offsets along the proto-Ulakhan fault. Our recent field investigations along the Ulakhan fault near the southern edge of the Seimchan basin reveal sag features, pressure ridges, troughs, and a scarp sections that delineates the trace of the fault over ~10 km, across an alluvial fan. These features can be traced within the basin on satellite images to the northwest and southeast of our survey and show left-lateral strike-slip motion associated with the fault. Previous studies support recent offset of up to 24 km as evidenced by river offsets observed northwest of the basin in the Chersky Range. Recent uplift adjacent to the Ulakhan fault and subsequent subsidence within the Seimchan basin may have been recorded by the down cutting of the Kolyma and Indigirka Rivers that have left a series of preserved meander terrace plateaus along the southern and northern margins of the basin. If one accounts for the present location of abandoned incised meanders on the north side of the basin, a 24 km offset is also apparent. A tectonic reconstruction of the area for a time prior to this offset using presumed fault motions shows that the Ulakhan fault system may be responsible for the development of the Seimchan-Buyunda basin as a large pull-apart structure. Seismicity along the Ulakhan fault has been poorly documented due to a lack of local seismic stations. However, preliminary field deployment with short-period instruments indicates a considerably higher level of seismicity than previously expected. Given the location of the Ulakhan fault along the suture boundary, new evidence for left- lateral offset, and recent seismicity, the Ulakhan clearly represented a major locus of displacement in the Pliocene that continues to take up considerable strain at the edge of the North American plate.

Mackey, K. G.; Hampton, B. A.; Fujita, K.; Kurtkin, S.; Gounbina, L. V.

2007-12-01

203

Structural mapping of northern Red Sea area, Egypt, using high resolution geophysical data  

NASA Astrophysics Data System (ADS)

Bouguer and high-resolution aeromagnetic maps were compiled for northern Red Sea region including Gulf of Suez and Gulf of Aqaba. This study provides a tectonic framework of the Precambrian faulted basement rocks and their orientation exposed or buried beneath the generally sedimentary rocks of the study area. The data analysis techniques applied included, normalized derivatives, 3D Euler deconvolutions and feature extraction calibrated using well logs data. Results of these techniques show that the study area has been affected by some major sets of structural systems, mainly trending in NNW, NW and NE directions along Red Sea, Gulf of Suez and Gulf of Aqaba. Moreover, some E-W and N-S structural trends were observed in Sinai and in western side of the River Nile (Eastern Desert). Also, many principal basement zones, structural and seismic active tectonic trends previously recognized were confirmed in this study. Furthermore, interpretations of both 3D magnetic modeling and 3D analytical signal techniques confirm the depths to the magnetic sources resulted by the 3D Euler technique. Whereas the basement could be observed on the ground (nearly 50 m over the ground) and become deeper than 5 km in some parts along the northern Red Sea region, indicating that, the Red Sea rift is subjected to strong tectonic activations. The aeromagnetic and Bouguer anomalies derived from the tilt derivative and horizontal derivative maps (TDR and H-TDR) were good identifiers the accommodation zones segmenting the Red Sea Rift. Finally, a complete set of processed geophysical maps for the northern Red Sea is presented in a hope that they can be useful for tracing the structural relationship of the entire region. The results are in agreement with the regional geophysical interpretation and the bathymetric expressions. Key words Red Sea Rift, Gulf of Suez, Bouguer and aeromagnetic anomalies, 3D Euler deconvolutions, analytical signals and normalized derivatives

Saleh, Salah; Saleh, Ahmed; Mekkawi, M.

2009-04-01

204

Using functional fault simulation and the difference fault model to estimate implementation fault coverage  

Microsoft Academic Search

An approach to estimate the fault coverage of the implementation of a VLSI design obtained by fault simulation at the function level is presented. The proposed methodology begins by defining a fault model for the functional level, the difference fault model (DFM), which reflects all of the faults in the implementation level. Functional fault detection is recorded by performing a

Gabriel M. Silberman; Ilan Y. Spillinger

1990-01-01

205

Fault model development for fault tolerant VLSI design  

NASA Astrophysics Data System (ADS)

Fault models provide systematic and precise representations of physical defects in microcircuits in a form suitable for simulation and test generation. The current difficulty in testing VLSI circuits can be attributed to the tremendous increase in design complexity and the inappropriateness of traditional stuck-at fault models. This report develops fault models for three different types of common defects that are not accurately represented by the stuck-at fault model. The faults examined in this report are: bridging faults, transistor stuck-open faults, and transient faults caused by alpha particle radiation. A generalized fault model could not be developed for the three fault types. However, microcircuit behavior and fault detection strategies are described for the bridging, transistor stuck-open, and transient (alpha particle strike) faults. The results of this study can be applied to the simulation and analysis of faults in fault tolerant VLSI circuits.

Hartmann, C. R.; Lala, P. K.; Ali, A. M.; Visweswaran, G. S.; Ganguly, S.

1988-05-01

206

Diagnosing CMOS bridging faults with stuck-at fault dictionaries  

Microsoft Academic Search

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

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

1990-01-01

207

Rough faults, distributed weakening, and off-fault deformation  

Microsoft Academic Search

We report systematic spatial variations in fault rocks along nonplanar strike-slip faults cross-cutting the Lake Edison Granodiorite, Sierra Nevada, California (Sierran wavy fault) and Lobbia outcrops of the Adamello Batholith in the Italian Alps (Lobbia wavy fault). In the case of the Sierran fault, pseudotachylyte formed at contractional fault bends, where it is found as thin (1–2 mm) fault-parallel veins.

W. Ashley Griffith; Stefan Nielsen; Giulio Di Toro; Steven A. F. Smith

2010-01-01

208

Isolability of faults in sensor fault diagnosis  

NASA Astrophysics Data System (ADS)

A major concern with fault detection and isolation (FDI) methods is their robustness with respect to noise and modeling uncertainties. With this in mind, several approaches have been proposed to minimize the vulnerability of FDI methods to these uncertainties. But, apart from the algorithm used, there is a theoretical limit on the minimum effect of noise on detectability and isolability. This limit has been quantified in this paper for the problem of sensor fault diagnosis based on direct redundancies. In this study, first a geometric approach to sensor fault detection is proposed. The sensor fault is isolated based on the direction of residuals found from a residual generator. This residual generator can be constructed from an input-output or a Principal Component Analysis (PCA) based model. The simplicity of this technique, compared to the existing methods of sensor fault diagnosis, allows for more rational formulation of the isolability concepts in linear systems. Using this residual generator and the assumption of Gaussian noise, the effect of noise on isolability is studied, and the minimum magnitude of isolable fault in each sensor is found based on the distribution of noise in the measurement system. Finally, some numerical examples are presented to clarify this approach.

Sharifi, Reza; Langari, Reza

2011-10-01

209

Fuzzy fault diagnostic system based on fault tree analysis  

Microsoft Academic Search

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

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

1995-01-01

210

On the Emulation of Software Faults by Software Fault Injection  

Microsoft Academic Search

This paper presents an experimental study on the emulation of software faults by fault injection. In a first experiment, a set of real software faults has been compared with faults injected by a SWIFI tool (Xception) to evaluate the accuracy of the injected faults. Results revealed the limitations of Xception (and other SWIFI tools) in the emulation of different classes

Henrique Madeira; Diamantino Costa; Marco Vieira

2000-01-01

211

An early fault diagnosis agreement under hybrid fault model  

Microsoft Academic Search

Reliability is an important research topic in distributed systems. To achieve suitable reliability, the fault tolerance of distributed systems must be studied. One of the most important issues surrounding fault tolerance is the Byzantine Agreement (BA) problem. The goal of BA is to achieve a common agreement among fault-free processors even where faults persist. Likewise, fault diagnosis agreement (FDA) the

Mao-lun Chiang; Shu-ching Wang; Lin-yu Tseng

2009-01-01

212

Red clover  

MedlinePLUS

... There isn’t enough information to rate the safety of red clover when applied to the skin. Special precautions & warnings: Pregnancy and breast-feeding: Red clover is LIKELY SAFE when taken by mouth in amounts commonly found in food. But it is ...

213

Red Water  

Microsoft Academic Search

IN connection with the letters on ``red water'' in NATURE of April 4 and 11, it may be of interest to state that a rusty-red coloration of brine and salt in evaporating pools of sea water is common on this coast.

Cyril Crossland

1912-01-01

214

Predicting Faults from Cached History  

Microsoft Academic Search

We analyze the version history of 7 software sys- tems to predict the most fault prone entities and files. The basic assumption is that faults do not occur in isolation, but rather in bursts of several related faults. Therefore, we cache locations that are likely to have faults: starting from the location of a known (fixed) fault, we cache the

Sunghun Kim; Thomas Zimmermann; E. James Whitehead Jr.; Andreas Zeller

2007-01-01

215

DELAY FAULT MODELS AND METRICS  

Microsoft Academic Search

The delay fault testing has become an important part of the overall test development process. But delay fault testing is not so mature as stuck-at fault testing. The paper surveys various delay fault models, their advantages and limitations. The current trends in test pattern generation for delay faults are analyzed, too. The test pattern gene- ration is directly related to

Vacius Jusas

216

Fail-Stutter Fault Tolerance  

Microsoft Academic Search

Traditional fault models present system designers with two ex- tremes: the Byzantine fault model, which is general and there- fore difficult to apply, and the fail-stop fault model, which is easier to employ but does not accurately capture modern device behav- ior. To address this gap, we introduce the concept of fail-stutter fault tolerance, a realistic and yet tractable fault

Remzi H. Arpaci-dusseau; Andrea C. Arpaci-dusseau

2001-01-01

217

It's Not Your Fault  

NSDL National Science Digital Library

In this lesson students will learn about tectonic plate movement. They will discover that we can measure the relative motions of the Pacific Plate and the North American Plate along the San Andreas Fault. Students will be able to compare and contrast movements on either side of the San Andreas Fault, calculate the amount of movement of a tectonic plate over a period of time, and describe the processes involved in the occurrence of earthquakes along the fault.

218

Fault tolerant EHA architectures  

NASA Astrophysics Data System (ADS)

An evaluation is conducted of fault-tolerant electrohydrostatic actuator (EHA) architectures applicable to prospective military aircraft, defining fault tolerances in terms of mission-success probability and safety reliability. The functional-level failure modes of an EHA and its interfacing equipment are used to analyze levels of fault coverage and redundancy required by MIL-F-9490 and MIL-STD 882B. A summary is presented of estimates of fault tolerance, performance, and weight of candidate EHA architectures, to allow selection of an architecture suited for a specific application.

Sadeghi, Tom; Lyons, Arthur

1992-03-01

219

Red Sky with Red Mesa  

ScienceCinema

With those fossil fuel reserves dwindling, the scientific race is on to convert the sunlight harvested by plants into new fuels that will augment and eventually replace petroleum. It's a critical challenge. But there is a powerful tool tackling it: Sandia National Laboratories' Red Sky Supercomputer with a special cluster called Red Mesa dedicated specifically to the National Renewable Energy Laboratory (NREL).

220

Red Capes, Red Herrings, and Red Flags.  

ERIC Educational Resources Information Center

The argument that the personality structures obtained from retrospective ratings reflect semantic similarity structures has been as provocative as a red cape in the bull ring. High congruence between those two kinds of structures seems well established. What is less clear is how and why those structures differ from that for immediate judgments of…

Fiske, Donald W.

221

How do we identify big rivers? And how big is big?  

NASA Astrophysics Data System (ADS)

“Big rivers” are the trunk rivers that carry the water and sediment load from major orogens, or that drain large areas of a continent. Identifying such rivers in the ancient record is a challenge. Some guidance may be provided by tectonic setting and sedimentological evidence, including the scale of architectural elements, and clues from provenance studies, but such data are not infallible guides to river magnitude. The scale of depositional elements is the most obvious clue to channel size, but evidence is typically sparse and inadequate, and may be misleading. For example, thick fining-upward successions may be tectonic cyclothems. Two examples of the analysis of large ancient river systems are discussed here in order to highlight problems of methodology and interpretation. The Hawkesbury Sandstone (Triassic) of the Sydney Basin, Australia, is commonly cited as the deposit of a large river, on the basis of abundant very large-scale crossbedding. An examination of very large outcrops of this unit, including a coastal cliff section 6 km long near Sydney, showed that even with 100% exposure there are ambiguities in the determination of channel scale. It was concluded in this case that the channel dimensions of the Hawkesbury rivers were about half the size of the modern Brahmaputra River. The tectonic setting of a major ancient fluvial system is commonly not a useful clue to river scale. The Hawkesbury Sandstone is a system draining transversely from a cratonic source into a foreland basin, whereas most large rivers in foreland basins flow axially and are derived mainly from the orogenic uplifts (e.g., the large tidally influenced rivers of the Athabasca Oil Sands, Alberta). Epeirogenic tilting of a continent by the dynamic topography process may generate drainages in unexpected directions. For example, analyses of detrital zircons in Upper Paleozoic Mesozoic nonmarine successions in the SW United States suggests significant derivation from the Appalachian orogen. Many large rivers in SE Asia flow along structural trends generated during the Himalayan orogeny (e.g., Brahmaputra/Jamuna, Irrawaddy, Mekong, Red), but evidence for large channel systems is not always present where it might be expected. For example, in the Gulf of Thailand, up to 8 km of Cenozoic nonmarine sediments have been recorded in fault-bounded basins, but seismic time-slice images of the Pliocene Holocene section indicate rivers of modest dimensions. The existing major trunk river, the Chao Phraya, which empties into the gulf at Bangkok, may be but a remnant of the Mekong, which was tectonically diverted to its present course at some point during the late Cenozoic.

Miall, Andrew D.

2006-04-01

222

Fault Tree Analysis of a Research Reactor. Computer Tools That Work.  

National Technical Information Service (NTIS)

Fault Tree Analysis Techniques have been used to assess the safety system of the ZED-2 Research Reactor at the Chalk River Nuclear Laboratories. This turned out to be a strong test of the techniques involved. The resulting fault tree was large and because...

J. A. Hall D. F. O'Dacre R. J. Chenier G. M. Arbique

1986-01-01

223

Active faulting and paleoseismology along the Bree fault, lower Rhine graben, Belgium  

NASA Astrophysics Data System (ADS)

Paleoseismic analysis of the 10-km-long Bree fault scarp in the lower Rhine graben yields numerous lines of evidence of earthquake activity in the Holocene and late Pleistocene. This active normal fault, a part of the Feldbiss fault system, dips 70°NE and is expressed at the surface by a prominent NW-SE trending 7 to 20 m high scarp, formed since the deposition of the Maas River main terrace <700 kyr. B.P. Trenches and geophysical prospecting show that the fault, which is known to have ˜100 m of vertical offset since the late Pliocene, breaks late Pleistocene and Holocene deposits. Ground-penetrating radar, seismic refraction, and electric tomography suggest that at shallow depth the amount of displacement is larger than the youngest vertical offset visible in the trenches and corresponds to cumulative fault displacements. The analysis of 36 leveling profiles across the scarp indicates that its height can be classified into three groups, likely corresponding to different events. A morphologic dating gives approximate ages of 2±1.5 kyr B.P., 14±5 kyr B.P., and 41±6 kyr B.P. for the past three surface-faulting earthquakes. Analysis of faulted stratigraphy and earthquake-induced deformation structures exposed in trenches suggests the occurrence of three large earthquakes during the past 45×l03 years and yields 0.07 mm/yr of relative vertical deformation rate. The most recent seismic event occurred between A.D. 610 and 890. The first identification of an active fault with surface ruptures in the lower Rhine graben area emphasizes that large earthquake sources exist within intraplate Europe and that at least some of these events are preserved in the geologic record.

Meghraoui, Mustapha; Camelbeeck, Thierry; Vanneste, Kris; Brondeel, Marijke; Jongmans, Denis

2000-06-01

224

Fault tree handbook  

Microsoft Academic Search

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

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

1981-01-01

225

Fault rocks lab  

NSDL National Science Digital Library

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

Singleton, John

226

Folds and Faults  

NSDL National Science Digital Library

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

227

Quantifying Anderson's fault types  

Microsoft Academic Search

Anderson [1905] explained three basic types of faulting (normal, strike-slip, and reverse) in terms of the shape of the causative stress tensor and its orientation relative to the Earth's surface. Quantitative parameters can be defined which contain information about both shape and orientation [Célérier, 1995], thereby offering a way to distinguish fault-type domains on plots of regional stress fields and

Robert W. Simpson

1997-01-01

228

Denali Fault: Gillette Pass  

USGS Multimedia Gallery

View northward of mountain near Gillette Pass showing sackung features. Here the mountaintop moved downward like a keystone, producing an uphill-facing scarp. The main Denali fault trace is on the far side of the mountain and a small splay fault is out of view below the photo....

2008-12-15

229

Denali Fault: Susitna Glacier  

USGS Multimedia Gallery

Helicopters and satellite phones were integral to the geologic field response. Here, Peter Haeussler is calling a seismologist to pass along the discovery of the Susitna Glacier thrust fault. View is to the north up the Susitna Glacier. The Denali fault trace lies in the background where the two lan...

2008-12-15

230

Testing for Design Faults  

Microsoft Academic Search

Existing theories of testing focus on verification. Their strategy is to cover a specification or a program text to a certain degree in order to raise the confidence in the correctness of a system under test. We take a dierent approach in the sense that we present a theory of fault-based testing. Fault-based testing uses test data designed to demonstrate

Bernhard K. Aichernig; Jifeng He

2005-01-01

231

Seismic expression of Buffalo deep fault, Buffalo, Wyoming  

SciTech Connect

A concealed, west-dipping, high-angle reverse fault, one of a pair first reported by N.H. Foster, P.E. Goodwin, and R.E. Fisher in 1969, has been interpreted from seismic profiles in the area south and west of Buffalo, Wyoming. The fault, named the Buffalo deep fault (BDF) by D.L. Blackstone, Jr., in 1981, trends generally north-northwest and dips westward along the deepest part of the Powder River basin near the western margin. The projected surface trace lies as much as 14 mi east of the nearest outcrop of Precambrian rocks on the eastern flank of the Bighorn Mountains. Offset on the BDF decreases upward through the Paleozoic section into younger rocks that have been folded into the synclinal bend of an east-facing monocline. The monocline, the BDF, and another reverse fault appear clearly on a high-quality seismic profile that trends east-west about 8 mi southwest of Buffalo, Wyoming. This profile is one of many that have been surveyed across the mountain front. Maximum throw across the BDF is about 4500 ft from the base of the Phanerozoic section. This throw, plus the steepened dips on the upthrown western block, account for only part of the large uplift on the Bighorn Mountains. The remainder of the uplift probably is the consequence of movement on younger thrust faults, strike-slip faults, and normal faults, many of which are exposed. The BDF, monocline, thrust faults, and strike-slip faults were formed by horizontal compression, a dominantly eastward component of movement for the Bighorn Mountain block with respect to the Powder River basin.

Hinrichs, E.N.; Grow, J.A.; Miller, J.J.; Lee, M.W.

1986-08-01

232

Solar system fault detection  

DOEpatents

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

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

1984-05-14

233

Rough faults, distributed weakening, and off-fault deformation  

NASA Astrophysics Data System (ADS)

We report systematic spatial variations in fault rocks along nonplanar strike-slip faults cross-cutting the Lake Edison Granodiorite, Sierra Nevada, California (Sierran wavy fault) and Lobbia outcrops of the Adamello Batholith in the Italian Alps (Lobbia wavy fault). In the case of the Sierran fault, pseudotachylyte formed at contractional fault bends, where it is found as thin (1-2 mm) fault-parallel veins. Epidote and chlorite developed in the same seismic context as the pseudotachylyte and are especially abundant in extensional fault bends. We argue that the presence of fluids, as illustrated by this example, does not necessarily preclude the development of frictional melt. In the case of the Lobbia fault, pseudotachylyte thickness varies along the length of the fault, but the pseudotachylyte veins thicken and pool in extensional bends. We conduct a quantitative analysis of fault roughness, microcrack distribution, stress, and friction along the Lobbia fault. Numerical modeling results show that opening in extensional bends and localized thermal weakening in contractional bends counteract resistance encountered by fault waviness, resulting in an overall weaker fault than suggested by the corresponding static friction coefficient. The models also predict static stress redistribution around bends in the faults which is consistent with distribution of microcracks, indicating significant elastic and inelastic strain energy is dissipated into the wall rocks due to nonplanar fault geometry. Together these observations suggest that damage and energy dissipation occurs along the entire nonplanar fault during slip, rather than being confined to the region close to the dynamically propagating crack tip.

Griffith, W. Ashley; Nielsen, Stefan; di Toro, Giulio; Smith, Steven A. F.

2010-08-01

234

Surface roughness evolution on experimentally simulated faults  

NASA Astrophysics Data System (ADS)

To investigate the physical processes operating in active fault zones, we conduct analogue laboratory experiments where we track the morphological and mechanical evolution of an interface during slip. Our laboratory friction experiments consist of a halite (NaCl) slider held under constant normal load that is dragged across a coarse sandpaper substrate. This set-up is a surrogate for a fault surface, where brittle and plastic deformation mechanisms operate simultaneously during sliding. Surface morphology evolution, frictional resistance and infra-red emission are recorded with cumulative slip. After experiments, we characterize the roughness developed on slid surfaces, to nanometer resolution, using white light interferometry. We directly observe the formation of deformation features, such as slip parallel linear striations, as well as deformation products or gouge. The striations are often associated with marginal ridges of positive relief suggesting sideways transport of gouge products in the plane of the slip surface in a snow-plough-like fashion. Deeper striations are commonly bounded by triangular brittle fractures that fragment the salt surface and efficiently generate a breccia or gouge. Experiments with an abundance of gouge at the sliding interface have reduced shear resistance compared to bare surfaces and we show that friction is reduced with cumulative slip as gouge accumulates from initially bare surfaces. The relative importance of these deformation mechanisms may influence gouge production rate, fault surface roughness evolution, as well as mechanical behavior. Finally, our experimental results are linked to Nature by comparing the experimental surfaces to an actual fault surface, whose striated morphology has been characterized to centimeter resolution using a laser scanner. It is observed that both the stress field and the energy dissipation are heterogeneous at all scales during the maturation of the interface with cumulative slip. Importantly, we show that the formation of striations on fault planes by mechanical abrasion involves transport of gouge products in the fault plane not only along the slip direction, but also perpendicular to it.

Renard, François; Mair, Karen; Gundersen, Olav

2012-12-01

235

Extensional faulting in southern Klamath Mountains, California  

NASA Astrophysics Data System (ADS)

Large northeast striking normal faults in the southern Klamath Mountains may indicate that substantial crustal extension occurred during Tertiary time. Some of these faults form grabens in the Jurassic and older bedrock of the province. The grabens contain continental Oligocene or Miocene deposits (Weaverville Formation), and in two of them the Oligocene or Miocene is underlain by Lower Cretaceous marine formations (Great Valley sequence). At the La Grange gold placer mine the Oligocene or Miocene strata dip northwest into the gently southeast dipping mylonitic footwall surface of the La Grange fault. The large normal displacement required by the relations at the La Grange mine is also suggested by omission of several kilometers of structural thickness of bedrock units across the northeast continuation of the La Grange fault, as well as by significant changes in bedrock across some northeast striking faults elsewhere in the Central Metamorphic and Eastern Klamath belts. The Trinity ultramafic sheet crops out in the Eastern Klamath terrane as part of a broad northeast trending arch that may be structurally analogous to the domed lower plate of metamorphic core complexes found in eastern parts of the Cordillera. The northeast continuation of the La Grange fault bounds the southeastern side of the Trinity arch in the Eastern Klamath terrane and locally cuts out substantial lower parts of adjacent Paleozoic strata of the Redding section. Faults bounding the northwestern side of the Trinity arch generally trend northeast and juxtapose stacked thrust sheets of lower Paleozoic strata of the Yreka terrane against the Trinity ultramafic sheet. Geometric relations suggest that the Tertiary extension of the southern Klamath Mountains was in NW-SE directions and that the Redding section and the southern part of the Central Metamorphic terrane may be a large Tertiary allochthon detached from the Trinity ultramafic sheet. Paleomagnetic data indicate a lack of rotation about a vertical axis during the extension. We propose that the Trinity ultramafic sheet is structurally analogous to a metamorphic core complex; if so, it is the first core complex to be described that involves ultramafic rocks. We infer that Mesozoic terrane accretion produced a large gravitational instability in the crust that spread laterally during Tertiary extension.

Schweickert, Richard A.; Irwin, William P.

1989-02-01

236

How clays weaken faults.  

NASA Astrophysics Data System (ADS)

The weakness of upper crustal faults has been variably attributed to (i) low values of normal stress, (ii) elevated pore-fluid pressure, and (iii) low frictional strength. Direct observations on natural faults rocks provide new evidence for the role of frictional properties on fault strength, as illustrated by our recent work on samples from the San Andreas Fault Observatory at Depth (SAFOD) drillhole at Parkfield, California. Mudrock samples from fault zones at ~3066 m and ~3296 m measured depth show variably spaced and interconnected networks of displacement surfaces that consist of host rock particles that are abundantly coated by polished films with occasional striations. Transmission electron microscopy and X-ray diffraction study of the surfaces reveal the occurrence of neocrystallized thin-film clay coatings containing illite-smectite (I-S) and chlorite-smectite (C-S) phases. X-ray texture goniometry shows that the crystallographic fabric of these faults rocks is characteristically low, in spite of an abundance of clay phases. 40Ar/39Ar dating of the illitic mix-layered coatings demonstrate recent crystallization and reveal the initiation of an "older" fault strand (~8 Ma) at 3066 m measured depth, and a "younger" fault strand (~4 Ma) at 3296 m measured depth. Today, the younger strand is the site of active creep behavior, reflecting continued activation of these clay-weakened zones. We propose that the majority of slow fault creep is controlled by the high density of thin (< 100nm thick) nano-coatings on fracture surfaces, which become sufficiently smectite-rich and interconnected at low angles to allow slip with minimal breakage of stronger matrix clasts. Displacements are accommodated by localized frictional slip along coated particle surfaces and hydrated smectitic phases, in combination with intracrystalline deformation of the clay lattice, associated with extensive mineral dissolution, mass transfer and continued growth of expandable layers. The localized concentration of smectite in both I-S and C-S minerals, which probably extends to greater depths (<10 km) is responsible for fault weakening, with cataclasis and fluid infiltration creating nucleation sites for neomineralization on displacement surfaces during continued faulting. The role of newly grown, ultrathin, hydrous clay coatings on displacement surfaces in the San Andreas Fault contrasts with previously proposed scenarios of reworked talc/serpentine phases as an explanation for weak faults and creep behavior at these depths.

van der Pluijm, Ben A.; Schleicher, Anja M.; Warr, Laurence N.

2010-05-01

237

System fault diagnostics using fault tree analysis  

Microsoft Academic Search

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

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

2008-01-01

238

Fault Scarp Offsets and Fault Population Analysis on Dione  

Microsoft Academic Search

Cassini images of Dione show several fault zones cutting through the moon's icy surface. We have measured the displacement and length of 271 faults, and estimated the strain occurring in 6 different fault zones. These measurements allow us to quantify the total amount of surface strain on Dione as well as constrain what processes might have caused these faults to

S. Tarlow; G. C. Collins

2010-01-01

239

A CMOS fault extractor for inductive fault analysis  

Microsoft Academic Search

The inductive fault analysis (IFA) method is presented and a description is given of the CMOS fault extraction program FXT. The IFA philosophy is to consider the causes of faults (manufacturing defects) and then simulate these causes to find the faults that are likely to occur in a circuit. FXT automates IFA for a CMOS technology by generating a list

F. Joel Ferguson; John Paul Shen

1988-01-01

240

Lake Clark fault, assessment of tectonic activity based on reconnaissance mapping of glacial deposits, northwestern Cook Inlet Alaska  

NASA Astrophysics Data System (ADS)

The Lake Clark fault extends ~247 km from the vicinity of Lake Clark in the Alaska-Aleutian Range batholith northeastward to the Castle Mountain fault along the northern margin of Cook Inlet. Documented Tertiary deformation along the fault includes dextral offsets (5-26 km) and north-side-up reverse displacements (500-1,000 m). The fault is along strike with the Holocene-active Castle Mountain fault and adjacent to the active northern Cook Inlet fold belt. As part of the STATEMAP program, the State of Alaska has begun a 2-year geologic mapping project in the vicinity of the Lake Clark fault, including assessment of Quaternary fault activity and its role in accommodating deformation in the Aleutian forearc. Here we present preliminary Quaternary mapping and tectonic geomorphic observations aimed at assessing the fault activity. Between the Beluga and Chakachatna rivers, large lateral moraines of the late Wisconsinan Naptowne glaciation cross the fault and are not displaced. In the vicinity of Lone Ridge, the fault is expressed as a ~25-m southeast-facing scarp in bedrock associated with springs and vertically offset Stage 4 or 6 moraines. In the Chuitna River drainage basin beyond the Naptowne ice limit, the fault extends across a fairly flat plateau with drumlins and ice-stagnation deposits related to Stage 4 or 6 glaciation. There the fault is expressed by subtle vegetation and tonal lineaments on air photos; however, scarps and lateral offsets were not observed. Stream profiles perpendicular to the fault along the Chuitna River and Chuitna Creek have convex profiles that could be related to tectonic folding. Our observations indicate that this part of the Lake Clark fault may be Quaternary active, but has been relatively quiescent in the late Pleistocene. Thus, blind thrust faults associated with the northern Cook Inlet fold belt may accommodate the majority of the tectonic deformation in this part of the Aleutian forearc. This information is applicable to earthquake hazard assessments for the Cook Inlet region.

Reger, R. D.; Koehler, R. D.

2009-12-01

241

Seismic site characterization for the Deep-Fault-Drilling-Project Alpine Fault  

NASA Astrophysics Data System (ADS)

The Alpine Fault in New Zealand (South Island) is one of the largest active plate-bounding continental fault zones on earth with earthquakes of magnitude 7.9 occuring every 200-400 years. Due to the surface exposure and the shallow depth of mechanical and chemical transitions it is a globally significant natural laboratory. Within the ICDP Deep-Fault-Drilling-Project Alpine Fault (DFDP-AF; https://wiki.gns.cri.nz/DFDP) a drill hole shall give insight into the geological structure of the fault zone and its evolution to understand the related deformation and earthquake processes. With the help of advanced seismic imaging techniques the shallow structure of the Alpine Fault is imaged to find the most suitable drill site location. A new seismic reflection profile has been acquired in 2011 by the WhataDUSIE project team consisting of partners from the University of Otago (New Zealand), TU Bergakademie Freiberg (Germany) and the University of Alberta (Canada). The reflection profile, located in the Whataroa river valley, has a total length of about 5 km. Up to 643 geophones with spacings between 4-8 m recorded the approximately 100 shot points along the profile line. Single shot gathers as well as preliminary imaging results will be presented. The high-quality data show various indicators of the Alpine Fault such as strong reflections and distorted first-arrival wavefields which are clearly visible already in single shot gathers. With the help of high resolution seismic images we can study the shallow structures of the subsurface thus gaining information about the location and dip of reflectors. Further detailed processing and intensive interpretative work will enable a seismic site characterization providing important information for the selection of the borehole location. Additionally the high resolution seismic images themselves allow a better understanding of the tectonic and geodynamic settings.

Glomb, Vera; Buske, Stefan; Kovacs, Adrienn; Gorman, Andrew

2013-04-01

242

A Dynamic Fault Classification Scheme  

Microsoft Academic Search

In this paper, we introduce a novel and simple fault rate classification scheme in hardware. It is based on the well-known threshold scheme, counting ticks between faults. The innovation is to introduce variable thre- shold values for the classification of fault rates and a fixed threshold for permanent faults. In combination with field data obtained from 9728 processors of a

Bernhard Fechner

243

Fault-slip analyses of brittle structures in the Corruvagge valley along the Pärvie fault in North Sweden  

NASA Astrophysics Data System (ADS)

More than a dozen large faults have been subjected to glacially-induced faulting in northern Scandinavia. These faults are usually SE dipping, SW-NE oriented thrusts, and they could be of Precambrian age with a long deformation history including repeated periods of reactivations. Based on their size, it has been proposed that these faults have hosted unusually large intraplate earthquakes. These faults are the targets for a scientific drilling project under development for the International Continental Scientific Drilling Program (ICDP), the "Drilling into Active Faults in Northern Europe" (Kukkonen et al. 2010). A major issue to be address before submitting the full IDCP proposal regards the question: Did the fault scarps host one large mega-earthquake or has it hosted several smaller events. To address this question, a field study was conducted in the summer of 2011, at three locations along the Pärvie fault in northern Sweden. The Pärvie fault scarp is ~160 km in length and 10-15 m in height, and it is the longest known postglacial fault in the world. It is suggested that the Pärvie fault hosted a mega-earthquake (M?8.2; Arvidsson, 1996) at the end or just after the last ice age, and seismic monitoring reveal that it remains seismically active today (e.g. Lindblom, 2011), with several hundreds of microearthquakes a year (M?3). Brittle structures were first collected in two locations by Riad (1990). Additional data have now been collected at three new locations. The Corruvagge valley is the most impressive site from the recent campaign, where data were collected along a profile that followed a dried-up river valley that cuts the Pärvie fault at approximately a perpendicular angle. This site offers a unique opportunity for a detailed investigation of brittle deformation from the hanging wall to the foot wall. About 1000 kinematic indicators were collected, in at least three different fracture filling minerals. We are currently in the process of evaluating structural fault-slip analyses of brittle structures; (2) chemical identification of minerals; and (3) assess the age of one sample. The anticipated results from the fault-slip analysis is the relative age between structures and together with the paleostress analysis and the absolute dating it will strengthen the chronological order of the different stress fields that has affected the fault through time.

Bäckström, A.; Rantakokko, N.; Ask, M. V. S.

2012-04-01

244

Faults and Folds Animation  

NSDL National Science Digital Library

This animation explores the forces and processes that deform rocks by creating folds, faults, and mountain ranges. You will learn how landmasses move, see the resulting deformation, and learn how this deformation relates to plate tectonics.

2002-01-01

245

Stacking faults in magnesium  

SciTech Connect

The energetics of various low-energy intrinsic, extrinsic, and twinlike stacking fault configurations in hexagonal-close-packed magnesium are determined from first-principles calculations. To zeroth-order, the ordering of the energies can be understood in terms of the number of fcc-like planes in the sequence of close-packed planes. However, such a simple model fails to quantitatively reproduce the calculated energies of the faults. We propose a model based on a local bond orientation scheme which reproduces the calculated results and is able to accurately predict the energies of arbitrary stacking sequences. This model has only two independent parameters, the energy of the intrinsic I{sub 1} stacking fault and the energy difference between hcp and fcc Mg. Both energy and entropy considerations suggest that isolated I{sub 1} stacking faults should predominate. {copyright} {ital 1997} {ital The American Physical Society}

Chetty, N. [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)]|[Department of Physics, University of Natal, Private Bag X01, Scottsville 3209 (South Africa); Weinert, M. [Department of Physics, Brookhaven National Laboratory, Upton, New York 11973-5000 (United States)

1997-11-01

246

Drivers at Fault  

Microsoft Academic Search

Using log-linear modeling techniques, the probability of fault among collision-involved drivers in Hawaii is related to three categorical variables: age, sex, and vehicle type. Very young and very old drivers face up to three times the risk of being at fault compared to middle-aged drivers. Substantial gender effects also occur at both ends of the age distribution. Pickup truck drivers

Karl Kim; Lei Li; James Richardson; Lawrence Nitz

1998-01-01

247

Large-scale splay faults on a strike-slip fault system: The Yakima Folds, Washington State  

NASA Astrophysics Data System (ADS)

The Yakima Folds (YF) comprise anticlines above reverse faults cutting flows of the Miocene Columbia River Basalt Group of central Washington State. The YF are bisected by the ~1100-km-long Olympic-Wallowa Lineament (OWL), which is an alignment of topographic features including known faults. There is considerable debate about the origin and earthquake potential of both the YF and OWL, which lie near six major dams and a large nuclear waste storage site. Here I show that the trends of the faults forming the YF relative to the OWL match remarkably well the trends of the principal stress directions at the end of a vertical strike-slip fault. This comparison and the termination of some YF against the OWL are consistent with the YF initially forming as splay faults caused by an along-strike decrease in the amount of strike-slip on the OWL. The hypothesis is that the YF faults initially developed as splay faults in the early to mid Miocene under NNW-oriented principal compressive stress, but the anticlines subsequently grew with thrust motion after the principal compressive stress direction rotated to N-S or NNE after the mid-Miocene. A seismic profile across one of the YF anticlines shows folding at about 7 km depth, indicating deformation of sub-basalt strata. The seismic profile and the hypothesized relationship between the YF and the OWL suggest that the structures are connected in the middle or lower crust, and that the faults forming the YF are large-scale splay faults associated with a major strike-slip fault system.

Pratt, Thomas L.

2012-11-01

248

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

Microsoft Academic Search

Lowside (footwall) closures sealed by reverse-slip faults and convergent strike-slip faults offer opportunities for significant field extension and new field prospects in basins deformed by contraction. The faults have reverse separation in cross section and transverse closure (in the direction of reservoir dip) is often provided by dip of beds away from the fault at structural upturns. The upturns are

T. P. Harding; A. C. Tuminas

1988-01-01

249

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

NASA Astrophysics Data System (ADS)

High-resolution seismic (shear-wave) reflection profiles were collected over a segment of the Hovey Lake fault, a known Paleozoic fault within a system of faults in the southernmost Wabash River valley of the central United States. Although the system of faults, called the Wabash Valley fault system, lie in an area of recognized prehistoric and contemporary seismicity, their seismogenic potential remain poorly defined, however. Consequently, the objectives of this study were to assess the Hovey Lake fault, one of the more prominent fault strands in the system, for neotectonic reactivation, and if present, collect sediment samples for dateable material from the disrupted horizons to provide an age constraint for the movement. The resultant stacked profiles show high-angle deformation extending above the Paleozoic bedrock, and into Upper Quaternary sediment. Time displacement calculations from the data show approximately 10.5 m of offset on the top-of-bedrock horizon, and 2 m of inverted displacement along the earliest-arriving Quaternary soil reflector at a depth of 5 m. Preliminary correlative coring found organic material in a disrupted soil horizon located 7.7 m below ground surface. Subsequent carbon-14 testing of the deeper horizon allows us to place a maximum age constraint at this site of approximately 37,000 YBP.

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

2004-12-01

250

Northern Arm Fault and the location of the Appalachian ocean suture in Newfoundland  

SciTech Connect

The Northern Arm Fault is a major crustal fracture which separates the Exploits and Botwood tectonostratigraphic zones of central Newfoundland. Several authors have correlated it with the Reach Fault to the north, and the Noels Paul Line and Cape Ray Fault to the south. Because this fault system was suggested to separate vastly different faunal provinces it has often been regarded as the suture zone marking the place where the Appalachian (alias Iapetus) Ocean finally closed during the Acadian Orogeny. The Northern Arm Fault was structurally analyzed at Northern Arm, Bay of Exploits, using: (1) fracture surface orientations; (2) slickenline stria; (3) fault gouge foliations and; (4) extensional vein orientations. Orientations and characteristics of these structures were found to be compatible with right-lateral motion along the Northern Arm Fault. A regional geologic synthesis suggests that this dextral fault system does not mark the location of the Appalachian Ocean suture but, rather, represents a major wrench fault possibly developed, within a zone of oblique convergence, prior to the Acadian Orogeny. The distribution of sedimentary and volcanic rocks (Botwood Group) in a basin to the east of the Northern Arm Fault suggests that they were deposited in a pull-apart basin during late-Silurian movement along this fault system; however, some motion occurred again during the Devonian. The Appalachian Ocean suture must therefore lie further to the east, possibly along the Gander River - Carmanville melange belt.

Kusky, T.M.; Poissant, S.A.

1985-01-01

251

Rough Faults, Distributed Weakening, and Off-Fault Deformation  

NASA Astrophysics Data System (ADS)

We report systematic spatial variations of fault rocks along non-planar strike-slip faults cross-cutting the Lake Edison Granodiorite, Sierra Nevada, California (Sierran Wavy Fault) and the Lobbia outcrops of the Adamello Batholith in the Italian Alps (Lobbia Wavy Fault). In the case of the Sierran fault, pseudotachylyte formed at contractional fault bends, where it is found as thin (1-2 mm) fault-parallel veins. Epidote and chlorite developed in the same seismic context as the pseudotachylyte and are especially abundant in extensional fault bends. We argue that the presence of fluids, as illustrated by this example, does not necessarily preclude the development of frictional melt. In the case of the Lobbia fault, pseudotachylyte is present in variable thickness along the length of the fault, but the pseudotachylyte veins thicken and pool in extensional bends. The Lobbia fault surface is self-affine, and we conduct a quantitative analysis of microcrack distribution, stress, and friction along the fault. Numerical modeling results show that opening in extensional bends and localized thermal weakening in contractional bends counteract resistance encountered by fault waviness, resulting in an overall weaker fault than suggested by the corresponding static friction coefficient. Models also predict stress redistribution around bends in the faults which mirror microcrack distributions, indicating significant elastic and anelastic strain energy is dissipated into the wall rocks due to non-planar fault geometry. Together these observations suggest that, along non-planar faults, damage and energy dissipation occurs along the entire fault during slip, rather than being confined to the region close to the crack tip as predicted by classical fracture mechanics.

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

2009-12-01

252

Fault Detection and Classification  

NASA Astrophysics Data System (ADS)

Plasma processes are used widely in the manufacture of semiconductor devices. Recent trends in this industry have focussed on methods for automated process control. For limiting processes such as plasma etch, an emerging focus is on real time Fault Detection and Classification (FDC). Simply put, the aim is to provide a system that not only detects faults but also identifies the root cause. For example, semiconductor production fabs regularly encounter faults that result in unscheduled tool downtime and reduced yield. Among these are real-time process and tool faults, post maintenance recovery problems and tool mis-matching at start-up and process transfer. The objective of any FDC scheme should be to reduce this product loss and tool downtime by identifying the core problem as rapidly as possible, and replace the usual "trial-and-error" approach to fault identification. There are a couple of key requirements in any control system. Firstly, an estimation of the process state, and secondly, a scheme for providing real-time control. This paper focuses on methods for addressing both problems on plasma etch tools. A non-intrusive high-resolution RF sensor is used to provide in situ process-state and tool-state data. Examples will be presented on how such a sensor can give a repeatable fingerprint of any plasma process. The challenge then becomes the manipulation of this data into usable information. The process control scheme presented is knowledge-based, in that it is trained and does not rely on statistical methods with underlying assumptions of Gaussian data spread. A fingerprint of known fault states is the knowledge set and real-time control is provided by comparison of the sensor fingerprint to the fault fingerprints.

Scanlan, John

2004-09-01

253

Thermochronological investigation of fault zones  

NASA Astrophysics Data System (ADS)

The timing of faulting episodes can be constrained by radiometric dating of fault-zone rocks. Fault-zone material suitable for dating is produced by tectonic processes, such as (1) fragmentation of host rocks, followed by grain-size reduction and recrystallization to form mica and clay minerals, (2) secondary heating/melting of host rocks by frictional fault motions, and (3) mineral vein formation as a result of fluid advection associated with the fault motions. The thermal regime of fault zones consists primarily of the following three factors: (a) regional geothermal structure across the fault zone and background thermal history of studied province bounded by fault systems, (b) frictional heating of wall rocks by fault motions, and (c) heating of host rocks by hot fluid advection in and around the fault zone. Thermochronological methods widely applied in fault zones are K-Ar (40Ar/39Ar), fission-track, and U-Th methods, for which methodological principles as well as analytical procedures are briefly described. The thermal sensitivities of individual thermochronological systems are then reviewed, which critically control the response of each method against the thermal processes. Based on the knowledge above, representative examples as well as key issues are highlighted to date fault gouges, pseudotachylytes, mylonites and carbonate veins, placing new constraints upon geological, geomorphological and seismological frames. Finally, the Nojima Fault is presented as an example for multiple applications of thermochronological methods in a complex fault zone.

Tagami, Takahiro

2012-05-01

254

INVASION DYNAMICS OF RED SHINERS (CYPRINELLA LUTRENSIS) IN SOUTHEASTERN STREAMS  

EPA Science Inventory

Red shiners have invaded a range of North American ecosystems, including several southeastern U.S. river drainages. A principle consequence of these invasions is extirpation of native congeners, either through competition or hydridization. We are conducting research to identify...

255

3-D mapping of segmented active faults in the Vienna Basin from integrated geophysical, geomorphological and geological data: building up an active fault database  

NASA Astrophysics Data System (ADS)

The Vienna Basin basin formed as a Miocene pull-apart basin along a sinistral transform system between the Eastern Alps and the Carpathians. Moderate seismicity in the southern Vienna Basin as well as thick Quaternary deposits in the center of the basin prove that part of the faults within the Miocene basin are active today. However, nearly no systematical data exist on the positions, segmentation, and geometry of active faults, which yield important input parameters for seismic hazard evaluations. Spatial mapping of active faults and kinematical analyses are based on 3-D reflection seismic data by OMV Austria, geomorphological features such as tilted Quaternary river terraces and fault scarps, the geometry of Quaternary basins, and published geodetic data. Interpretation of combined data sets are summarized in a map and an active fault catalog of for future seismic hazard evaluations. The map reveals two regions with different types of Quaternary and active faults. (A) The southern part of the Vienna Basin reveals a seismically active NE-striking sinistral strike-slip fault with a large negative flower structure. Recent activity of the flower structure is documented by the accumulation of up to 150 m thick Quaternary gravels. The Quaternary basin is limited by faults, depicted by 3-D seismics and near surface geophysics (Gegenleitner et al, 2003, this volume). At the surface, a prominent morphological scarp parallels the fault traces mapped from the 3-D seismic. (B) The western and central part of the Vienna Basin is characterized by major listric E-dipping normal faults branching off from the strike-slip fault system, which is localized in the seismically active area at the eastern border of the Basin. Deformation is partitioned on several normal faults via a common detachment horizon. These faults kinematically link up with the strike-slip fault system. At the surface normal faulting is documented by tilted Quaternary terraces of the Danube caused by the hangingwall collapse above listric faults. Major branch points are marked by changes in the geomorphological expression and Quaternary basin architecture, indicating a segmentation of the main fault along strike. We propose that at least one major mapped branch point coincide with a seismogenic segment-boundary at depth. This interpretation is supported by hypocenters clustering near the two adjacent fault segments mapped in the 3-D seismic survey. However, not all major branch points are presently defined well enough to allow an assessment of fault segment surfaces for the calculation of earthquake magnitudes.

Hinsch, R.; Decker, K.

2003-04-01

256

Geologically recent near-surface faulting in the Valley and Ridge Province: New exposures of extensional faults in alluvial deposits, Giles County, SW Virginia  

SciTech Connect

New excavations along the north side of the New River Valley between Pembroke and Pearisburg in Giles County, Virginia, have revealed two extensional faults cutting a series of alluvial terrace deposits composed of stratified, but unconsolidated, conglomerates, gravels and silts. Although the age of neither the faults nor the sediments is currently known, the unconsolidated nature of the alluvial deposits suggests that both are, geologically, relatively recent (tertiary or Quaternary). Both faults dip away from the New River valley and are marked by 15--20 cm wide zones of clay-rich gouge. Within these gouge zones, the basal planes of individual clay grains are oriented parallel to the planar gouge zones margins and define a macroscopic foliation. This foliation truncates stratification in both the adjacent hangingwall and footwall of each fault and is oriented at a high angle to stratification. No dragging over of stratification into the fault zones is observed. Foliation development is inferred to have involved recrystallization of clay minerals, probably in association with fluid flow along the fault zones. The authors currently interpret these features as indicating that the faults formed in response to tectonic rather than surficial processes. Seismic monitoring studies over the last twenty years in this part of the Valley and Ridge Province have indicated that earthquake foci are located within crystalline basement beneath the thrust zone detachment surface at depths greater than 5 km. No seismic or geological evidence for near-surface faulting appears to have previously been recorded in this area. Therefore, these faults are of considerable importance to both the assessment of seismic hazard and to the understanding of fault development in this area as they indicate the, at least local occurrence, of geologically recent near-surface faulting.

Bollinger, G.A.; Law, R.D.; Pope, M.C.; Wirgart, R.H.; Whitmarsh, R.S. (Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Geological Sciences)

1992-01-01

257

Solar system fault detection  

SciTech Connect

This patent describes an apparatus for detecting predetermined faults in a variety of active, different solar systems. Each of the different solar systems uses a heat transfer fluid and has a tank for receiving fluid or a heat exchanger to transfer heat from the heat transfer fluid to a tank, and at least one collector and one pipe through which fluid flows. The different solar systems each has different predetermined operating conditions associated with a given type of fault, comprising: a. sensing means for sensing the presence of different predetermined operating conditions associated with each of the solar systems. Each of the sensing means includes a switch that changes in state in response to a change in a predetermined operating condition in at least one of the fluid, tank or heat exchanger, collector, and pipe; b. means in communication with each of the sensing means for determining whether one or more predetermined faults have occurred in one of the solar systems, the means for determining including combining means. The combining means includes logic gates at least one of which is actuated by logic gate actuating voltages via the associated states of at least two of the switches to produce an output signal indicative of whether a predetermined fault is present in the one solar system; and c. indicating means responsive to the output signal for indicating the presence and identity of the one predetermined fault in the one solar system.

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

1986-12-02

258

Evidence of coseismic ruptures along the Roum fault (Lebanon): a possible source for the AD 1837 earthquake  

Microsoft Academic Search

The Roum fault is the westernmost branch within the Lebanese restraining bend of the Dead Sea Transform Fault. This strike-slip fault extends for about 35km from north of the Hula basin to the Awali river, and shows left-lateral strike-slip displacements (manifested as offset streams) and vertical movements. Recent seismic records indicate its seismogenic potential as the source of the double

Tony Nemer; Mustapha Meghraoui

2006-01-01

259

Timing of left-lateral shearing along the Ailao Shan-Red River shear zone: constraints from zircon U-Pb ages from granitic rocks in the shear zone along the Ailao Shan Range, Western Yunnan, China  

NASA Astrophysics Data System (ADS)

As the boundary between the Indochina and the South China blocks, the Ailao Shan-Red River (ASRR) shear zone underwent a sinistral strike-slip shearing which is characterized by ductile deformation structures along the Ailao Shan range. The timing issue of left-lateral shearing along the ASRR shear zone is of first-order importance in constraining the nature and regional significance of the shear zone. It has been, therefore, focused on by many previous studies, but debates still exist on the age of initiation and termination of shearing along the shear zone. In this paper, we dated 5 samples of granitic plutons (dykes) along the Ailao Shan shear zone. Zircon U-Pb ages of four sheared or partly sheared granitic rocks give ages of 30.9 ± 0.7, 36.6 ± 0.1, 25.9 ± 1.0 and 27.2 ± 0.2 Ma, respectively. An undeformed granitic dyke intruding mylonitic foliation gives crystallization age of 21.8 ± 1 Ma. The Th/U ratios of zircon grains from these rocks fall into two populations (0.17-1.01 and 0.07-0.08), reflecting magmatic and metamorphic origins of the zircons. Detailed structural and microstructural analysis reveals that the granitic intrusions are ascribed to pre-, syn- and post-shearing magmatisms. The zircon U-Pb ages of these granites provide constraints on timing of the initiation (later than 31 Ma from pre-shearing granitic plutons, but earlier than 27 Ma from syn-shearing granitic dykes) and termination (ca. 21 Ma from the post-shearing granitic dykes) of strong ductile left-lateral shearing, which is consistent with previous results on the Diancang Shan and Day Nui Con Voi massifs in the literature. We also conclude that the left-lateral shearing along the ASRR shear zone is the result of southeastward extrusion of the Indochina block during the Indian-Eurasian plate collision. Furthermore, the left-lateral shearing was accompanied by the ridge jump, postdating the opening, of the South China Sea.

Tang, Yuan; Liu, Junlai; Tran, My-Dung; Song, Zhijie; Wu, Wenbin; Zhang, Zhaochong; Zhao, Zhidan; Chen, Wen

2012-11-01

260

Timing of left-lateral shearing along the Ailao Shan-Red River shear zone: constraints from zircon U-Pb ages from granitic rocks in the shear zone along the Ailao Shan Range, Western Yunnan, China  

NASA Astrophysics Data System (ADS)

As the boundary between the Indochina and the South China blocks, the Ailao Shan-Red River (ASRR) shear zone underwent a sinistral strike-slip shearing which is characterized by ductile deformation structures along the Ailao Shan range. The timing issue of left-lateral shearing along the ASRR shear zone is of first-order importance in constraining the nature and regional significance of the shear zone. It has been, therefore, focused on by many previous studies, but debates still exist on the age of initiation and termination of shearing along the shear zone. In this paper, we dated 5 samples of granitic plutons (dykes) along the Ailao Shan shear zone. Zircon U-Pb ages of four sheared or partly sheared granitic rocks give ages of 30.9 ± 0.7, 36.6 ± 0.1, 25.9 ± 1.0 and 27.2 ± 0.2 Ma, respectively. An undeformed granitic dyke intruding mylonitic foliation gives crystallization age of 21.8 ± 1 Ma. The Th/U ratios of zircon grains from these rocks fall into two populations (0.17-1.01 and 0.07-0.08), reflecting magmatic and metamorphic origins of the zircons. Detailed structural and microstructural analysis reveals that the granitic intrusions are ascribed to pre-, syn- and post-shearing magmatisms. The zircon U-Pb ages of these granites provide constraints on timing of the initiation (later than 31 Ma from pre-shearing granitic plutons, but earlier than 27 Ma from syn-shearing granitic dykes) and termination (ca. 21 Ma from the post-shearing granitic dykes) of strong ductile left-lateral shearing, which is consistent with previous results on the Diancang Shan and Day Nui Con Voi massifs in the literature. We also conclude that the left-lateral shearing along the ASRR shear zone is the result of southeastward extrusion of the Indochina block during the Indian-Eurasian plate collision. Furthermore, the left-lateral shearing was accompanied by the ridge jump, postdating the opening, of the South China Sea.

Tang, Yuan; Liu, Junlai; Tran, My-Dung; Song, Zhijie; Wu, Wenbin; Zhang, Zhaochong; Zhao, Zhidan; Chen, Wen

2013-04-01

261

Spectral source parameters for three earthquakes in the southern Red Sea  

Microsoft Academic Search

We obtained spectral source parameters for one event on the axial trough and two events on a presumed transform fault, all in the southern part of the Red Sea. Seismic moments obtained range from 0.3 × 1025 to 15 × 1025 dyn cm. The normal fault mechanism event on the axial trough shows a low stress drop of 7 bars

Fekadu Kebede; Torild van Eck

1990-01-01

262

A Numerical Investigation of Drainage Network Evolution During Fault Interaction and Linkage  

NASA Astrophysics Data System (ADS)

We have coupled together a numerical fault growth model and a surface process model (CASCADE; Braun and Sambridge, Basin Research, 9, 27-52, 1997) to study the way in which drainage basin geometry and river long profiles respond to the progressive formation and linkage of an underlying fault network. The numerical fault growth model simulates nucleation, propagation and displacement accumulation on a population of steeply dipping extensional faults. Elastic interaction between faults is included, resulting in significant displacement rate variations in space (along neighbouring fault segments) and through time. The most significant temporal variations in slip rate are those associated with fault linkage events in which the linking fault segments experience increased rates of slip while adjacent faults in foot-wall and hanging-wall areas become inactive. The size, elevation and lateral continuity of topographic uplifts (footwall highs) and depocentres (hanging-wall lows) vary through time as the faults grow and link. The faults appear as sub-vertical scarps that can grow in height and length through time. Fluvial erosion, diffusive hill-slope processes, landsliding, lake formation and sediment deposition are all included in the surface process model. Orographic effects are not considered. The tectonic model outputs maps of elevation change. These maps are input sequentially into the surface process model to drive tectonic elevation changes while erosion and deposition are ongoing. The spatial and temporal scales of the coupled model have been chosen to correspond with an area of active extensional faulting in Lazio-Abruzzo, Italy. Normal fault development in this area during the last 3 Myrs has resulted in interaction and incipient linkage between several fault segments that vary in length from 20 to 40 km, within a ~150 km long fault array. For this area we have river long profiles derived from a high-resolution DEM, and field measurements of river channels crossing faults that have experienced a temporal variation in throw rate. These data will be compared directly with outputs from the coupled numerical model.

Cowie, P. A.; Naylor, M.; Whittaker, A.

2003-12-01

263

The main features of morphostructure of the transregional Amur-Songhua-Huanghe fault zone in east Asia  

Microsoft Academic Search

The cooperative Russian-Chinese morphostructural investigations have been carried out during the last several years along\\u000a the transregional fault zone—Amur-Songhua-Huanghe Lineament, which is stretching from the lower Huanghe (Yellow) River across\\u000a the Bohai Sea to Liaohe-Songhua and further along the lower Amur River to North Sakhalin (more than 3000 km). It is the wide\\u000a fault zone (some hundred km) that has

A. P. Kulakov; E. A. Miasnikov; S. M. Tashchi; Shanwen Qiu; Huachang Zhao; Qusheng Li

1997-01-01

264

Effect of Los Lobos thrust fault on tertiary recovery in west San Ardo oil field, Salinas Basin, California  

Microsoft Academic Search

Field observations and correlation of wireline logs from wells in the west San Ardo oil field reveal the geometry and character of the Los Lobos thrust fault. The Los Lobos thrust is a northwest-trending, southwest-dipping fault of Pliocene to Pleistocene age, located in the southwest Salinas basin. The surface trace separates the Salinas River on the east from the Aurignac

J. E. Laing

1988-01-01

265

Quaternary faulting history along the Deep Springs fault, California  

Microsoft Academic Search

New geologic mapping, structural stud- ies, geochronology, and diffusion erosion modeling along the Deep Springs fault, Cal- ifornia, shed light on its Quaternary fault- ing history. The Deep Springs fault, a 26- km-long, predominantly north-northeast- striking, west-northwestdipping normal fault bounding the eastern side of Deep Springs Valley, cuts Jurassic batholithic rocks nonconformably overlain by middle Miocene to Pleistocene stream gravels,

Jeffrey Lee; Charles M. Rubin; Andrew Calvert

2001-01-01

266

Structural analysis of compressional and extensional deformation within the Wood River and Milligen Formations, south-central, Idaho  

SciTech Connect

The Pennsylvanian to Permian Wood River Formation consists of calcareous and siliciclastic rocks that were deposited unconformably on argillaceous rocks of the Devonian Milligen Formation. The original depositional contact between the two formations is preserved locally; however, the contact was also mapped as a thrust, a normal fault, a reactivated thrust with a normal sense of movement, and as a sheared unconformity with an indeterminate sense of movement. Early reverse movement with northeast tectonic transport along the Milligen-Wood River contact is documented by mesoscopic and microscopic field evidence, including Riedel shears, drag folds, angular relations of cleavage in the fault plane, and oriented thin sections. Faults that separate middle Wood River in the upper plate from upper Wood River in the lower plate are also associated with this early phase of thrusting. Tertiary extensional deformation resulted in high-angle and low-angle normal faulting with some reactivation of Mesozoic thrusts. High-angle fault have normal, dip-slip or normal, obliquie-slip movements. Low-angle normal faults with north-west to southwest tectonic transport cut the Milligen and Wood River Formations, as well as units within the Tertiary Challis Volcanics. The movement sense on the normal faults in documented by drag folds, the angular relation of extension joints relative to the fault plane, shear steps, and oriented thin sections. Faults that separate younger sequences of the Wood River in the upper plate from older sequences in the lower plate are also associated with this phase of normal faulting.

Ratchford, M.E.; Reid, R.R. (Univ. of Idaho, Moscow, ID (United States). Dept. of Geology and Geological Engineering)

1993-04-01

267

Stresses and Faulting  

NSDL National Science Digital Library

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

Reinen, Linda

268

Tectonic geomorphology and paleoseismology of strike-slip faults in Jamaica: Implications for distribution of strain and seismic hazard along the southern edge of the Gonave microplate  

NASA Astrophysics Data System (ADS)

The east-west, left lateral strike-slip fault system forming the southern edge of the Gonave microplate crosses the110-km-long and 70-km-wide island of Jamaica. GPS measurements in the northeastern Caribbean are supportive of the microplate interpretation and indicate that ~ half of the Caribbean-North America left-lateral plate motion (8-14 mm/yr) is carried by the Plantain Garden (PGFZ) and associated faults in Jamaica. We performed Neotectonic mapping of the Plantain Garden fault along the southern rangefront of the Blue Mountains and conducted a paleoseismic study of the fault at Morant River. Between Holland Bay and Morant River, the fault is characterized by a steep, faceted, linear mountain front, prominent linear valleys and depressions, shutter ridges, and springs. At the eastern end of the island, the PGFZ is characterized by a left-stepping fault geometry that includes a major, active hot spring. The river cut exposure at Morant River exposes a 1.5-m-wide, sub-vertical fault zone juxtaposing sheared alluvium and faulted Cretaceous basement rocks. This section is overlain by an, unfaulted 3-m-thick fluvial terrace inset into a late Pleistocene terrace that is culturally modified. Upward fault terminations indicate the occurrence of three paleoearthquakes that occurred prior to deposition of the flat lying inset terrace around 341-628 cal yr BP. At this time, our radiocarbon results suggest that we can rule out the PGFZ as the source of the 1907 Kingston earthquake 102 years ago, as well as, the 1692 event that destroyed Port Royal 317 years ago and produced a major landslide at Yallahs. Pending OSL ages will constrain the age of the penultimate and most recent ruptures. Gently to steeply dipping rocks as young as Pliocene exposed in roadcuts within the low coastal hills south of and parallel to the Plantain Garden fault may indicate active folding and blind thrust faulting. These structures are poorly characterized and may accommodate an unknown amount of oblique strain. Reconnaissance mapping was also performed along the South Coast fault in south-central Jamaica north of Portland Ridge, and along the Crawle River-Rio Minho fault near Frankfield in the Central Inlier. The absence of fault scarps or other tectonic geomorphic features across fluvial terraces of the Milk and Minho Rivers indicate that the South Coast fault has not been active in Holocene time. Left laterally offset streams, linear valleys, and saddles support active faulting along the east-west Crawle River-Rio Minho fault that is roughly collinear with the western extension of the Plantain Garden fault.

Koehler, R. D.; Mann, P.; Brown, L. A.

2009-12-01

269

Dynamic Processes of Fault Creep along the Chihshang Fault, Taiwan  

Microsoft Academic Search

Active fault creep along the Chihshang fault in Taiwan has been observed for the past 20 years (Lee et al., 2004). The Chihshang Creepmeter experiment was set up across this most active segment along the Longitudinal Valley fault system, the present-day plate suture between the Eurasian and the Philippine Sea plates in eastern Taiwan. The daily creep data revealed an

Y. Zeng; Z. Shen; J. Lee

2005-01-01

270

Faulting Plumbing: Spring Response to Creep on the Hayward Fault  

NASA Astrophysics Data System (ADS)

Two prominent sets of thermal springs lie along the western edge of the left step over region between the Calaveras and Hayward faults: the Alum Rock springs, San Jose, CA, and the Warm Springs, Fremont, CA. Co- and postseismic flow increases at both spring locations have been well documented (King et al., 1994 and Waring, 1915). Until recently, however, spring response to creep events was unknown. In January 2003, we documented a 20% decrease in discharge at the Warm Springs due to a 0.31mm right lateral creep event on the southern Hayward fault. The Warm Springs emanate from the Warm Springs fault that lies at the base of Mission Peak and merges with the Mission fault. The observed decrease in discharge is directly proportional to fluid pressure drop within the fault and therefore we suggest that creep on the Hayward fault resulted in a rapid stress change within a neighboring secondary fault. We present an analytical model that explains the observed discharge change and provides an estimate for the depth of fault zone permeability changes. Our results indicate that ongoing monitoring, geochemical sampling, and modeling of thermal springs within active faults zones offers the potential to directly observe fluid-fault interactions and better constrain the interactions of major fault zones with neighboring secondary faults.

Manga, M.; Rowland, J. C.

2003-12-01

271

Fault model development for fault tolerant VLSI design  

Microsoft Academic Search

Fault models provide systematic and precise representations of physical defects in microcircuits in a form suitable for simulation and test generation. The current difficulty in testing VLSI circuits can be attributed to the tremendous increase in design complexity and the inappropriateness of traditional stuck-at fault models. This report develops fault models for three different types of common defects that are

C. R. Hartmann; P. K. Lala; A. M. Ali; G. S. Visweswaran; S. Ganguly

1988-01-01

272

Fault-Scarp Degradation  

NSDL National Science Digital Library

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

Pinter, Nicholas

2010-09-27

273

Wrench faulting in selected areas of Permian Basin  

SciTech Connect

Landsat and NASA High Altitude Special Mission Aircraft imagery have made it possible to define at least six separate lineament trends between the Amarillo-Wichita uplift (N62/sup 0/W) and the Texas lineament (N54/sup 0/W) that are 200 to 330 mi (320 to 530 km) long and oriented N54/sup 0/W to N62/sup 0/W. These long lineaments are thought to be P shears and are left-lateral wrench faults by definition. This left-lateral wrench fault system has been demonstrated at the Carta Valley fault zone. The Permian surface between Brown-Bassett and JM field of Terrell, Crockett, and Val Verde Counties along the Pecos River has a fracture system that is compatible with wrench faulting. In Garza and Borden Counties, the elements of left-lateral wrench faulting can be demonstrated from high altitude aircraft imagery and demonstrated on the surface and in the subsurface with seismic support. Surface lineaments are observed on Landsat imagery throughout the Permian basin and lead to the belief that the very long N54/sup 0/ to 62/sup 0/W lineaments are P shears. The set oriented N86/sup 0/ +/- E are the Riedel shears and the N36/sup 0/E are conjugate Riedel shears. These for high angle en echelon faults at the surface in Borden and Garza Counties, and with the surface alignments being documented on CDP seismic lines in the subsurface.

Bolden, G.P.

1984-01-01

274

Analyzing Fault/Fracture Patterns  

NSDL National Science Digital Library

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

Jamie

275

THE LITTLE WASHITA RIVER EXPERIMENTAL WATERSHED  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Little Washita River Experimental Watershed (LWREW) located in the Red River Basin of the Southern Great Plains near Chickasha, OK is one of USDA Agricultural Research Service's largest and best-instrumented watersheds. The LWREW drains an area of 610 square kilometers and is characterized by v...

276

Interaction between normal fault slip and erosion on relief evolution: Insights from experimental modelling  

NASA Astrophysics Data System (ADS)

The growth of relief in active tectonic areas is mainly controlled by the interactions between tectonics and surface processes (erosion and sedimentation). The study of long-lived morphologic markers formed by these interactions can help in quantifying the competing effects of tectonics, erosion and sedimentation. In regions experiencing active extension, river-long profiles and faceted spurs (triangular facets) can help in understanding the development of mountainous topography along normal fault scarps. In this study, we developed analogue experiments that simulate the morphologic evolution of a mountain range bounded by a normal fault. This paper focuses on the effect of the fault slip rate on the morphologic evolution of the footwall by performing three analogue experiments with different fault slip rates under a constant rainfall rate. A morphometric analysis of the modelled catchments allows comparing with a natural case (Tunka half-graben, Siberia). After a certain amount of fault slip, the modelled footwall topographies of our models reaches a dynamic equilibrium (i.e., erosion balances tectonic uplift relative to the base level) close to the fault, whereas the topography farther from the fault is still being dissected due to regressive erosion. We show that the rates of vertical erosion in the area where dynamic equilibrium is reached and the rate of regressive erosion are linearly correlated with the fault throw rate. Facet morphology seems to depend on the fault slip rate except for the fastest experiment where faceted spurs are degraded due to mass wasting. A stream-power law is computed for the area wherein rivers reach a topographic equilibrium. We show that the erosional capacity of the system depends on the fault slip rate. Finally, our results demonstrate the possibility of preserving convex river-long profiles on the long-term under steady external (tectonic uplift and rainfall) conditions.

Strak, V.; Dominguez, S.; Petit, C.; Meyer, B.; Loget, N.

2011-12-01

277

Fault reconstruction from sensor and actuator failures  

Microsoft Academic Search

Many fault detection filters have been developed to detect and identify sensor and actuator faults by using analytical redundancy. In this paper, an approach for reconstructing sensor and actuator faults from the residual generated by the fault detection filter is proposed. The transfer matrix from the faults to the residual is derived in terms of the eigenvalues of the fault

Robert H. Chen; Jason L. Speyer

2001-01-01

278

Anastomosing grabens, low-angle faults, and Tertiary thrust( ) faults, western Markagunt Plateau, southwestern Utah  

SciTech Connect

A structurally complex terrane composed of grabens and horsts, low-angle faults, Tertiary thrust( ) faults, gravity-slide blocks, and debris deposits has been mapped along the western Markagunt Plateau, east of Parowan and Summit, southwestern Utah. This terrane, structurally situated within the transition between the Basin and Range and Colorado Plateau provinces, contains Tertiary volcanic and sedimentary and Cretaceous sedimentary rocks. The structures are mostly Miocene to Oligocene but some are Pleistocene. The oldest structure is the Red Hills low-angle shear zone, interpreted as a shallow structure that decoupled an upper plate composed of a Miocene-Oligocene volcanic ash-flow tuff and volcaniclastic succession from a lower plate of Tertiary sedimentary rocks. The period of deformation on the shear zone is bracketed from field relationships between 22.5 and 20 Ma. The graben-horst system trends northeast and formed after about 20 Ma (and probably much later) based on displacement of dated dikes and a laccolith. The central part of the system contains many grabens that merge toward its southerly end to become a single graben. Within these grabens, (1) older structures are preserved, (2) debris eroded from horst walls forms lobe-shaped deposits, (3) Pleistocene basaltic cinder cones have localized along graben-bounding faults, and (4) rock units are locally folded suggesting some component of lateral translation along graben-bounding faults. Megabreccia deposits and landslide debris are common. Megabreccia deposits are interpreted as gravity-slide blocks of Miocene-Oligocene( ) age resulting from formation of the Red Hills shear zone, although some may be related to volcanism, and still others to later deformation. The debris deposits are landslides of Pleistocene-Pliocene( ) age possibly caused by continued uplift of the Markagunt Plateau.

Maldonado, F.; Sable, E.G. (Geological Survey, Denver, CO (United States))

1993-04-01

279

Fault Detection in Routing Protocols  

Microsoft Academic Search

Routing protocol faults cause problems ranging from an inability to communicate to excessive routing overhead. This paper proposes a system for detecting a wide range of routing protocol faults. Our system deploys virtual routers called RouteMonitors to monitor a routing protocol. We de- ployed RouteMonitors in the MBone's DVMRP infrastruc- ture and uncovered a number of faults. We were also

Daniel Massey; Bill Fenner

1999-01-01

280

Optimum Fault Current Limiter Placement  

Microsoft Academic Search

Due to the difficulty in power network reinforcement and the interconnection of more distributed generations, fault current level has become a serious problem in transmission and distribution system operations. The utilization of fault current limiters (FCLs) in power system provides an effective way to suppress fault currents and result in considerable saving in the investment of high capacity circuit breakers.

Jen-Hao Teng; Chan-Nan Lu

2007-01-01

281

Tolerating transient faults in MARS  

Microsoft Academic Search

The concepts of transient fault handling in the MARS architecture are discussed. After an overview of the MARS architecture, the mechanisms for the detection of transient faults are discussed in detail. In addition to extensive checks in the hardware and in the operating system, time-redundant execution of application tasks is proposed for the detection of transient faults. The time difference

H. Kopetz; H. Kantz; G. Grunsteidl; P. Puschner; J. Reisinger

1990-01-01

282

Adaptive fault tolerance  

NASA Astrophysics Data System (ADS)

The objective of the Adaptive Fault Tolerance program is to provide large complex distributed military systems with greater degrees of survivability, and graceful degradation than is currently available. Most research on these systems to date has focused on the management of static threat and environmental conditions. However, many military Battle Management/Command, Control, Communication, and Intelligence systems exist not in a static but in a highly dynamic environment. The dynamics occur along several dimensions such as alternate modes of operation, changing threat type or threat rate, loss of system resources such as communication links or processing assets, and changing network topology and asset configuration. Using static fault tolerance approaches in these systems is inappropriate because system requirements may change as a result of changes along one or more dimensions in the dynamic operating environment. Furthermore, designing a system for worst-case situations in every dimension of conceivable threat is cost prohibitive. An adaptive approach to fault management enables the system to dynamically tailor its fault tolerance/survivability mechanisms to best deal with a changing environment and to apply limited system assets appropriately.

Armstrong, Len T.

1994-05-01

283

Row fault detection system  

SciTech Connect

An apparatus, program product and method check for nodal faults in a row of nodes by causing each node in the row to concurrently communicate with its adjacent neighbor nodes in the row. The communications are analyzed to determine a presence of a faulty node or connection.

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

2012-02-07

284

Formal Fault Tree Semantics  

Microsoft Academic Search

In train control systems, more and more (electro-)mechanical devices are substituted by software based devices. To sustain the high level safety standards for these embedded systems, we propose the integration of fault tree analysis and formal methods. This combines two important safety analysis methods from the involved domains of engineering and software development. Our approach proposes to build a formal

Gerhard Schellhorn; Andreas Thums; Wolfgang Reif Lehrstuhl

2002-01-01

285

Fault-Related Sanctuaries  

Microsoft Academic Search

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

L. Piccardi

2001-01-01

286

River Sinuosity Classification - Case study in the Pannonian Basin  

NASA Astrophysics Data System (ADS)

A new evaluation method is proposed to classify the multiple window-size based sinuosity spectrum, in order to minimize the possible human interpretation error. If the river is long enough for the analysis, the classification could be similarly useful as the sinuosity spectrum is, but sometimes it is more straightforward. Furthermore, for the classification, we did not need the main parameters of the river, e.g. the bankfull discharge. The river sinuosity values were studied in the Pannonian Basin in order to reveal neotectonic influence on their abrupt changes. The map sheets of the Second Military Survey of the Habsburg Empire were used to digitize the natural, pre-regulation meandering river thalwegs. 28 rivers were studied, and the connection between the known fault lines and the river sinuosity changes was detected in 36 points, along 26 structural lines. An unsupervised ISOCLASS classification was carried out on these data, and the sinuosity values were divided into 5 classes. Because of the sinuosity calculation method, 25 kilometer-long river sections are missing at the two endpoints of the channel. So sometimes the displayed section of the river does not cross to the faults represented on the neotectonic map. In the other cases, where the faults are crossing the rivers, the results are corresponding with the results of the sinuosity spectrum: the river-points on the two sides of the faults belong to different classes. The connection between these fault lines and the change of river sinuosity classes was detected in 23 points, along 16 structural lines The research is made in the frame of project OTKA-NK83400 (SourceSink Hungary). The European Union and the European Social Fund also have provided financial support to the project under the grant agreement no. TÁMOP 4.2.1./B-09/1/KMR-2010-0003.

Petrovszki, J.; Székely, B.; Timár, G.

2012-04-01

287

Fault-Related Sanctuaries  

NASA Astrophysics Data System (ADS)

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

Piccardi, L.

2001-12-01

288

Fault Scarp Offsets and Fault Population Analysis on Dione  

NASA Astrophysics Data System (ADS)

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

Tarlow, S.; Collins, G. C.

2010-12-01

289

Geology Fieldnotes: Yukon - Charley Rivers National Preserve, Alaska  

NSDL National Science Digital Library

This National Park Service (NPS) site provides information on the Yukon - Charley Rivers National Preserve in Alaska, including geology, visitor information, photographs, and links to further resources. The Yukon is a large river flowing along a fault through Alaska, and the Charley is a major tributary flowing into it. Some gold rush history is discussed, as well as wildlife and vegetation.

290

Deep Structure and Earthquake Generating Properties in the Yamasaki Fault Zone Estimated from Dense Seismic Observation  

NASA Astrophysics Data System (ADS)

We have been estimating crustal heterogeneous structure and earthquake generating properties in and around the Yamasaki fault zone, which is a left-lateral strike-slip active fault with a total length of about 80 km in southwest Japan. We deployed dense seismic observation network, composed of 32 stations with average spacing of 5-10 km around the Yamasaki fault zone. We estimate detailed fault structure such as fault dip and shape, segmentation, and possible location of asperities and rupture initiation point, as well as generating properties of earthquakes in the fault zone, through analyses of accurate hypocenter distribution, focal mechanism, 3-D velocity tomography, coda wave inversion, and other waveform analyses. We also deployed a linear seismic array across the fault, composed of 20 stations with about 20 m spacing, in order to delineate the fault-zone structure in more detail using the seismic waves trapped inside the low velocity zone. We also estimate detailed resistivity structure at shallow depth of the fault zone by AMT (audio-frequency magnetotelluric) and MT surveys. In the scattering analysis of coda waves, we used 2,391 wave traces from 121 earthquakes that occurred in 2002, 2003, 2008 and 2009, recorded at 60 stations, including dense temporary and routine stations. We estimated 3-D distribution of relative scattering coefficients along the Yamasaki fault zone. Microseismicity is high and scattering coefficient is relatively larger in the upper crust along the entire fault zone. The distribution of strong scatterers suggests that the Ohara and Hijima faults, which are the segments in the northwestern part of the Yamasaki fault zone, have almost vertical fault plane from surface to a depth of about 15 km. We used seismic network data operated by Universities, NIED, AIST, and JMA. This study has been carried out as a part of the project "Study on evaluation of earthquake source faults based on surveys of inland active faults" by Japan Nuclear Energy Safety Organization (JNES). Fig.1 (a) Horizontal distribution of relative scattering coefficients, averaged for a depth range from 0 to 15 km. Open and solid symbols represent stronger and weaker scattering than the average, respectively. (b) Distribution of relative scattering coefficients, inside the rectangular area shown in (a), projected on a vertical cross section along the Yamasaki fault zone. Red crosses show distribution of microearthquakes in 2002, 2003, 2008 and 2009 (JMA data). The Yamasaki fault zone is composed of Ohara (OF), Hijima (HF), Yasutomi (YF), Kuresakatoge (KF), Biwako (BF), and Miki faults (MF), whose approximate location is shown at the top.

Nishigami, K.; Shibutani, T.; Katao, H.; Yamaguchi, S.; Mamada, Y.

2010-12-01

291

Reconstructing Fault History from Fault Rocks and Travertine Deposits, Rock Canyon Fault, Utah  

NASA Astrophysics Data System (ADS)

Central Utah lies along the eastern border of the Basin and Range Province. Within this region the Rock and Dry Canyon's graben structure is a block dropped down by oblique faults with an anomalous east-west orientation relative to other Basin and Range structures. Travertine is a rock composed of calcium carbonate that is commonly associated with faults, particularly active faults. The geometry and the macro/microstructures of travertine can provide a record of the evolution of the fault through time. The objectives of this study are to document the evidence of fault history contained in travertine formed along the Rock Canyon fault in order to test the hypothesis that this is a young, potentially active structure contributing to Basin and Range Province deformation. Polished rock slabs prepared from travertine samples collected along the mapped Rock Canyon fault show a wide range of textures, including columnar, radial/fibrous, banded, bedded, botryoidal, and brecciated travertine (broken, cemented fault rock) along with fibrous, brecciated, and blocky crystalline calcite. Angular clasts of layered travertine, deposited along the fault at an earlier stage, are contained within breccias documenting a subsequent slip event (or events). Therefore, initial observations on fault rock textures indicate that there were multiple slip episodes on the Rock Canyon fault. More detailed microscopic observations on thin sections prepared from the same samples will constrain the number and type of fracturing, fault slip, and vein precipitation events that occurred.

Main, J.; Wilson, T. J.

2011-12-01

292

Red Files  

NSDL National Science Digital Library

Red Files, a four-part documentary series from PBS, utilizes previously unavailable archival sources and interviews to present a fascinating look at the Soviet Union and its Cold War rivalry with the US. This attractive companion site offers a number of resources related to each of the four episodes: Secret Victories of the KGB, Soviet Sports Wars, Secret Soviet Moon Mission, and Soviet Propaganda. For each installment, users will find a story synopsis, the Producer's script, theme music, updates on related events, human interest stories, complete interview transcripts, video clips, a reference section, access to related sections of Russian Archives Online, maps, a timeline, lesson plans, and more. Additional offerings include a collection of links mentioned in the series and an internal search engine. This site joins an already strong tradition at PBS of creating sites that are actual companions to the program, offering new and expanded content for interested users.

293

Raft River geoscience case study  

SciTech Connect

The Raft River Geothermal Site has been evaluated over the past eight years by the United States Geological Survey and the Idaho National Engineering Laboratory as a moderate-temperature geothermal resource. The geoscience data gathered in the drilling and testing of seven geothermal wells suggest that the Raft River thermal reservoir is: (a) produced from fractures found at the contact metamorphic zone, apparently the base of detached normal faulting from the Bridge and Horse Well Fault zones of the Jim Sage Mountains; (b) anisotropic, with the major axis of hydraulic conductivity coincident to the Bridge Fault Zone; (c) hydraulically connected to the shallow thermal fluid of the Crook and BLM wells based upon both geochemistry and pressure response; (d) controlled by a mixture of diluted meteoric water recharging from the northwest and a saline sodium chloride water entering from the southwest. Although the hydrogeologic environment of the Raft River geothermal area is very complex and unique, it is typical of many Basin and Range systems.

Dolenc, M.R.; Hull, L.C.; Mizell, S.A.; Russell, B.F.; Skiba, P.A.; Strawn, J.A.; Tullis, J.A.

1981-11-01

294

Geomorphic and stratigraphic evidence for dynamic river channel development in the Dehra Dun region, northern India  

Microsoft Academic Search

The Ganga and Yamuna rivers drain the Garhwal Himalaya of northern India and cut cross several active faults as they pass into the Gangetic Plain and the northern Indian foreland. Unlike rivers in the central or eastern Himalayas, which debouch directly into the foreland and have built large depositional fan complexes, the Ganga and Yamuna rivers have been funnelled into

A. L. Densmore; R. Sinha; J. B. Barnes; J. Pickering; S. K. Tandon

2009-01-01

295

Holocene faulting on the Mission fault, northwest Montana  

SciTech Connect

South of Flathead Lake, fault scarps on late Quaternary surfaces are nearly continuous for 45 km along the western flank of the Mission Range. On late Pleistocene alpine lateral moraines, scarp heights reach a maximum of 17 m. Scarp heights on post glacial Lake Missoula surfaces range from 2.6--7.2 m and maximum scarp angles range from 10[degree]--24[degree]. The stratigraphy exposed in seven trenches across the fault demonstrates that the post glacial Lake Missoula scarps resulted from at least two surface-faulting events. Larger scarp heights on late Pleistocene moraines suggests a possible third event. This yields an estimated recurrence of 4--8 kyr. Analyses of scarp profiles show that the age of the most surface faulting is middle Holocene, consistent with stratigraphic evidence found in the trenches. Rupture length and displacement imply earthquake magnitudes of 7 to 7.5. Previous studies have not identified geologic evidence of late Quaternary surface faulting in the Rocky Mountain Trench or on faults north of the Lewis and Clark line despite abundant historic seismicity in the Flathead Lake area. In addition to the Mission fault, reconnaissance studies have located late Quaternary fault scarps along portions of faults bordering Jocko and Thompson Valleys. These are the first documented late Pleistocene/Holocene faults north of the Lewis and Clark line in Montana and should greatly revise estimates of earthquake hazards in this region.

Ostenaa, D.A.; Klinger, R.E.; Levish, D.R. (Bureau of Reclamation, Denver, CO (United States))

1993-04-01

296

Logs of Paleoseismic Excavations Across the Central Range Fault, Trinidad  

USGS Publications Warehouse

This publication makes available maps and trench logs associated with studies of the Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. Our studies were conducted in 2001 and 2002. We mapped geomorphic features indicative of active faulting along the right-lateral, Central Range Fault, part of the South American-Caribbean plate boundary in Trinidad. We excavated trenches at two sites, the Samlalsingh and Tabaquite sites. At the Samlalsingh site, sediments deposited after the most recent fault movement bury the fault, and the exact location of the fault was unknown until we exposed it in our excavations. At this site, we excavated a total of eleven trenches, six of which exposed the fault. The trenches exposed fluvial sediments deposited over a strath terrace developed on Miocene bedrock units. We cleaned the walls of the excavations, gridded the walls with either 1 m X 1 m or 1 m X 0.5 m nail and string grid, and logged the walls in detail at a scale of 1:20. Additionally, we described the different sedimentary units in the field, incorporating these descriptions into our trench logs. We mapped the locations of the trenches using a tape and compass. Our field logs were scanned, and unit contacts were traced in Adobe Illustrator. The final drafted logs of all the trenches are presented here, along with photographs showing important relations among faults and Holocene sedimentary deposits. Logs of south walls were reversed in Illustrator, so that all logs are drafted with the view direction to the north. We collected samples of various materials exposed in the trench walls, including charcoal samples for radiocarbon dating from both faulted and unfaulted deposits. The locations of all samples collected are shown on the logs. The ages of seventeen of the charcoal samples submitted for radiocarbon analysis at the University of Arizona Accelerator Mass Spectrometry Laboratory in Tucson, Ariz., are given in Table 1. Samples found in Table 1 are shown in red on the trench logs. All radiocarbon ages are calibrated and given with 2 standard deviation age ranges. Our studies suggest that the Central Range Fault is a Holocene fault capable of producing damaging earthquakes in Trinidad

Crosby, Christopher J.; Prentice, Carol S.; Weber, John; Ragona, Daniel

2009-01-01

297

Structural influence on hydrocarbon entrapment in the northwestern Red Sea, Egypt  

Microsoft Academic Search

The northwestern part of the Egyptian Red Sea has attracted the attention of many geologists because it lies at the triple junction of the main rifts between the Red Sea, the Gulf of Aqaba, and Gulf of Suez. The geometry of the fault system in this area of the basin clearly indicates an extensional setting. The area has a southwestward

M. G. Salah; A. S. Alsharhan

1996-01-01

298

Seismic Expression of Fault Related Folding in Southeastern Turkey  

Microsoft Academic Search

Weldon Beauchamp, and David McDonald,TransAtlantic Petroleum Corp. 5910 N. Central Expressway, Suite 1755, Dallas, TX 75206 weldon@tapcor.com, 214-395-7125 The Zagros fold belt extends northwest from Iran and Iraq into southeastern Turkey. Large scale fault related folds control the topography of this region and the path of the Tigris river. Large surface anticlines in the Zagros Mountains provide traps for giant

W. Beauchamp; D. McDonald

2009-01-01

299

75 FR 39839 - Regulated Navigation Area; Hudson River and Port of NY/NJ  

Federal Register 2010, 2011, 2012, 2013

...contractors, and with Hudson River and Sandy Hook Pilots. Discussion of Rule This...by Weeks Marine, Hudson River and Sandy Hook Pilots as requiring additional safety...northwest corner of Pier 41, Red Hook Brooklyn, all waters of the...

2010-07-13

300

Nature of the Red Sea crust: A controversy revisited  

Microsoft Academic Search

Whether the Red Sea floor is underlain mostly by oceanic or extended continental crustal material is a controversial topic. To test between the two hypotheses, we used a digital color mosaic of 23 Landsat thematic mapper (TM) scenes with field, geochemical, and geochronological data to identify and correlate crosscutting geologic features on the African and Arabian sides. Faults, shear zones,

M. Sultan; R. Becker; R. E. Arvidson; P. Shore; R. J. Stern; Z. El Alfy; E. A. Guinness

1992-01-01

301

Tectonics and paleogeography along the Amazon river  

Microsoft Academic Search

The main structural and geomorphological features along the Amazon River are closely associated with Mesozoic and Cenozoic tectonic events.The Mesozoic tectonic setting is characterised by the Amazonas and Marajó Basins, two distinct extensional segments. The Amazonas Basin is formed by NNE–SSW normal faults, which control the emplacement of dolerite dykes and deposition of the sedimentary pile. In the more intense

João Batista Sena Costa; Ruth Léa Bemerguy; Yociteru Hasui; Maur??cio da Silva Borges

2001-01-01

302

Earthquakes and Fault Lines  

NSDL National Science Digital Library

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

Bennington, Miss

2010-04-26

303

Folds, Faults, and Mountains  

NSDL National Science Digital Library

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

Smoothstone; Company, Houghton M.

304

Geotechnical reconnaissance of the 2002 Denali fault, Alaska, earthquake  

USGS Publications Warehouse

The 2002 M7.9 Denali fault earthquake resulted in 340 km of ruptures along three separate faults, causing widespread liquefaction in the fluvial deposits of the alpine valleys of the Alaska Range and eastern lowlands of the Tanana River. Areas affected by liquefaction are largely confined to Holocene alluvial deposits, man-made embankments, and backfills. Liquefaction damage, sparse surrounding the fault rupture in the western region, was abundant and severe on the eastern rivers: the Robertson, Slana, Tok, Chisana, Nabesna and Tanana Rivers. Synthetic seismograms from a kinematic source model suggest that the eastern region of the rupture zone had elevated strong-motion levels due to rupture directivity, supporting observations of elevated geotechnical damage. We use augered soil samples and shear-wave velocity profiles made with a portable apparatus for the spectral analysis of surface waves (SASW) to characterize soil properties and stiffness at liquefaction sites and three trans-Alaska pipeline pump station accelerometer locations. ?? 2004, Earthquake Engineering Research Institute.

Kayen, R.; Thompson, E.; Minasian, D.; Moss, R. E. S.; Collins, B. D.; Sitar, N.; Dreger, D.; Carver, G.

2004-01-01

305

Quaternary tectonics in the central Interandean Valley, Ecuador: Fault-propagation folds, transfer faults and the Cotopaxi Volcano  

Microsoft Academic Search

We studied the Quaternary tectonics of the central Interandean Valley (IV, Ecuador), around the active Cotopaxi volcano, by field geological–structural survey, analysis of seismicity, precise levelling of river terraces and numerical modelling. North of the volcano, there are main Quaternary west-dipping reverse faults located along the western side of the valley. At the Cotopaxi foothills, we found NNE-SSW-striking, vertical, right-lateral

Emilia Fiorini; Alessandro Tibaldi

306

Paleoseismological analysis of an intraplate extensional structure: the Concud fault (Iberian Chain, eastern Spain)  

Microsoft Academic Search

The Concud fault is a 13.5 km long, NW–SE striking normal fault at the eastern Iberian Chain. Its recent (Late Pleistocene)\\u000a slip history is characterized from mapping and trench analysis and discussed in the context of the accretion\\/incision history\\u000a of the Alfambra River. The fault has been active since Late Pliocene times, with slip rates ranging from 0.07 to 0.33 mm\\/year\\u000a that

P. Lafuente; L. E. Arlegui; C. L. Liesa; J. L. Simón

307

Reverse faulting Events of the Ohchigata Fault Zone, Central Japan  

NASA Astrophysics Data System (ADS)

The Ohchi plain is one of the NE-SW trending tectonic depressions located at the base of the Noto Peninsula protruding into the Japan Sea. Tectonic setting of this area has been changed from the tensional stress field related to the opening of the Japan Sea during Miocene into the compressional stress field after Pliocene. Geologists in 1930's discussed that geological structure of the both margins of this plain are controlled by normal faults or folds. In 1970's, geomorphologists referred that those are reverse faults and active during late Quaternary period based on the study on the terrace deformations. Our seismic reflection profiling surveys in 2001 and 2002 clearly imaged thrust faults dipping approximately 30 degrees to the mountain side beneath both of the margins of this plain. In 2003, we excavated a trench on the fault along the southwestern plain margin. The result shows that this fault has repeatedly been reactivated during late Pleistocene and the last faulting occurred around 3,000 years ago. Active faults along the margins of this plain are called the Ohchigata Fault Zone. Based on the topographic study using the aero-photographs, several tectonic landforms are identified on the alluvial terraces traversed by the Sekidosan fault along the southern margin of this plain. This fault strikes N45E and has produced a scarp about 2 m high at Mijiro site. In order to obtain the information on faulting history, we excavated a trench across the fault scarp at this site. On the trench walls, a reverse fault dipping 10 to 45 degrees to the southeast was exposed. On the upthrown side of the fault, thin terrace deposits in Holocene overlie late Pleistocene beds intercalating 2 layers of widespread volcanic ash, that may correspond to AT (29 ka) and Aso-4 (85-90 ka), respectively. The Pleistocene beds are extensively deformed and partly overturned near the fault. On the downthrown side, a layer of sand and gravel dated at around 3,000 yrs BP by 14C dating method (AMS) is vertically displaced about 2.2 m by this fault.

Azuma, T.; Shimokawa, K.; Mizuno, K.; Sugiyama, Y.; Sugito, N.; Tsutsumi, H.

2003-12-01

308

New geomorphic evidence probably provided by recent activities of the Gyaring Co Fault, Central Tibet  

NASA Astrophysics Data System (ADS)

The Gyaring Co Fault is one of the most active en echelon minor faults of the Karakoram-Jiali Fault zone (KJFZ) in the Tibetan Plateau. These minor en echelon faults have been affirmed as active right-lateral strike-slip faults, striking N120°-130°E. The Gyaring Co Fault is one of above-mentioned faults. According to previous study, the slip rate of it is about 10-20 mm/yr. A M7 event occurred in 1934 along the southern Gyaring Co Fault, while little has been known for the northern segment. Based on recent analysis by high resolution satellite images, we found various offset river channels to suggest the northern segment is still active as its southern counterpart. The evidence includes a number of 10- 12m offset or bending small creeks on the Quaternary terraces, which are perhaps produced by the last large earthquake event along the northern segment. Also found are ten meters to kilometer scale displacements, which are generally identified by larger river and must be cumulative offsets. For the purpose of deriving slip rates along this segment, dating methods of OSL, 10Be, and Radiocarbon are applied in this study. By the new findings along the Gyaring Co Fault, it can be further affirmed that the above-mentioned en echelon minor faults may play as southern boundary zone that marks. a fast eastward moving block in the Central Tibet. The recently published GPS velocities, showing a relatively large WNW-ESE extension rate of ~22 ± 3 mm/yr within the Tibetan plateau, also supports our finding. However, the northern boundary zone of this block still need further work to unravel.

Chung, L.; Chen, Y.; Yu, K.; Cao, Z.; Yin, G.

2010-12-01

309

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

NASA Astrophysics Data System (ADS)

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

Revil, A.; Cathles, L. M.

2002-09-01

310

Numerical modeling of the development of southeastern Red Sea continental margin  

Microsoft Academic Search

The Red Sea continental margin (RSCM) corresponds to a wide hinge zone between Red Sea and Arabian plate. This margin has\\u000a been studied through geological and geophysical observations primarily in regard to the evolution of Red Sea rift. This margin\\u000a is characterized by occurrence of thin sediments, significant onshore uplift, tectonic subsidence of the offshore sedimentary\\u000a basin, active faulting and

Sunil Kumar Dwivedi; Daigoro Hayashi

2009-01-01

311

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

SciTech Connect

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

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

1988-06-01

312

Simulation of internal faults in synchronous generators  

Microsoft Academic Search

An internal fault in the armature winding of a synchronous generator occurs due to the breakdown of the winding insulation. In this paper, a method for simulating internal faults in synchronous generators, using direct phase quantities, is described. Simulation results showing the fault currents, during a single phase to ground fault and a two phase to ground fault, are presented

A. I. Megahed; O. P. Malik

1999-01-01

313

Hiberarchy clustering fault diagnosis of hydraulic pump  

Microsoft Academic Search

Fault diagnosis is one of the key technologies of prognostic and health management system (PHM) of aircraft hydraulic system. Aiming at the strong coupling of various fault features of hydraulic pump when multiple faults occur simultaneously, a hiberarchy clustering fault diagnosis strategy was proposed, in which three level fault reasoning machine was adopted for five kinds of failures for hydraulic

Jun Du; Shaoping Wang

2010-01-01

314

Protecting distribution feeders for simultaneous faults  

Microsoft Academic Search

Overhead distribution systems may experience faults involving more than one feeder. During simultaneous faults, the transformer low-voltage-side overcurrent relay measures a current greater than the current measured by faulted feeder relays. Therefore, the transformer relay may trip faster than faulted feeder relays. Transformer relay misoperation affects service availability in circuits not involved with the fault. In this paper, we describe

J. Betanzos Manuel; H. E. Lemus Zavala; E. Alcazar Ramirez; D. Sanchez Escobedo; H. J. Altuve

2010-01-01

315

A Semantic Model of Program Faults  

Microsoft Academic Search

Program faults are artifacts that are widely studied, but there are many aspects of faults that we still do not understand. In addition to the simple fact that one important goal during testing is to cause failures and thereby detect faults, a full understanding of the characteristics of faults is crucial to several research areas in testing. These include fault-based

A. Jefferson Offutt; Jane Huffman Hayes

1996-01-01

316

Earthquake Faulting at Ancient Cnidus, SW Turkey  

Microsoft Academic Search

The ruins of Cnidus, an important ancient city in southwestern Asia Minor, lie directly on an earthquake fault — the Cnidus Fault. Offset and deformed archaeological remains along the trace of the fault testify to its recent activation. The ancient city's famous Round Temple of Aphrodite is vertically offset by 0.35 m across the fault. The fault also forms the

ERHAN ALTUNEL; IAIN S. STEWART; AYKUT BARKA; LUIGI PICCARDI

2003-01-01

317

Mechanical controls on fault geometry  

Microsoft Academic Search

Faults inevitably become non-planar because of how they grow and how they are affected during slip by mechanical heterogeneities inherent in the earth. Some faults acquire a non-planar geometry because of non-uniform tectonic deformation or because they grow by the linkage of originally discontinuous structures. However, even faults that are originally planar are unlikely to remain so. Elastic analyses show

Stephen J Martel

1999-01-01

318

Integrated fault tree development environment  

Microsoft Academic Search

Probabilistic Risk Assessment (PRA) techniques are utilized in the nuclear industry to perform safety analyses of complex defense-in-depth systems. A major effort in PRA development is fault tree construction. The Integrated Fault Tree Environment (IFTREE) is an interactive, graphics-based tool for fault tree design. IFTREE provides integrated building, editing, and analysis features on a personal workstation. The design philosophy of

1986-01-01

319

Compositional Temporal Fault Tree Analysis  

Microsoft Academic Search

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

Martin Walker; Leonardo Bottaci; Yiannis Papadopoulos

2007-01-01

320

Fault trees and sequence dependencies  

Microsoft Academic Search

One of the frequency cited shortcomings of fault-tree models, their inability to model so-called sequence dependencies, is discussed. Several sources of such sequence dependencies are discussed, and new fault-tree gates to capture this behavior are defined. These complex behaviors can be included in present fault-tree models because they utilize a Markov solution. The utility of the new gates is demonstrated

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

1990-01-01

321

Post-Miocene Faulting and Folding in the Southwestern Transverse Ranges, Santa Monica Bay, California  

NASA Astrophysics Data System (ADS)

We investigate patterns and timing of post-Miocene deformation, including folding and uplift of the Santa Monica Mountains, by mapping high-and low-angle faults and submerged geomorphic features in northeast Santa Monica Bay, California. Our multidisciplinary approach utilizes deep industry seismic reflection data, shallow high-resolution data, and USGS multibeam and NOAA point bathymetric data. We mapped a blind, north-dipping low-angle fault that extends approximately 50 km along strike in central and eastern Santa Monica Bay. This fault is interpreted to be a reactivated Miocene detachment fault that extends south of and beneath the active Santa Monica and Dume faults. The east-west trending central portion of the fault lies beneath the 10x15 km WNW-trending Shelf Projection anticlinorium offshore Manhattan Beach. Late Miocene and Pliocene strata are fully involved in the folding. Any continuing folding would absorb a blind thrust component of slip on the underlying low-angle fault. Continued activity is suggested by M5.0 thrust earthquakes in 1979 and 1989 that are spatially associated with the blind fault. Folding across the E-W-trending Santa Monica Mountains anticlinorium would also absorb thrust slip on the downdip projection of the blind low-angle fault and/or the moderately N-dipping Santa Monica-Dume fault. We mapped high-angle strands of the NW-SE San Pedro Basin and the E-W Malibu Coast faults. These faults cut to or near the seafloor, and the San Pedro Basin fault is associated with doubly-plunging seafloor folds. At present, it is unclear if these high-angle faults are deforming late Quaternary sediments. However, we are currently working on extending stratigraphic correlations from onshore and offshore industry wells through an elongate basin between the Shelf Projection anticlinorium and the Santa Monica fault. As another means to investigate active deformation in our study area, we are using GMT and the 3D visualization software GOCAD to create high resolution grids of bathymetry and slope gradient. Gridded surfaces can be displayed as shaded-relief in order to better visualize features such as submerged shorelines, fault scarps, and gullies. The same techniques will be applied onshore to the Santa Monica Mountains digital elevation model to visualize uplifted wave cut platforms, tilted river terraces, and variable stream gradients. We will use these submarine and surface geomorphic indicators to evaluate activity of the Shelf Projection and Santa Monica Mountains anticlinoria and of seafloor faults.

Broderick, K. G.; Sorlien, C. C.; Kamerling, M. J.; Seeber, L.; Luyendyk, B. P.

2002-12-01

322

Evidence for Active Strike-slip Faults in the Longmen Shan, Eastern Margin of Tibet  

NASA Astrophysics Data System (ADS)

Geomorphic evidence for Quaternary and Holocene-aged strike-slip faults was observed during reconnaissance field work in the Longmen Shan region, the boundary between the eastern Tibetan plateau and the Sichuan basin in west-central China. Active faults within the mountainous region include the N to NNE-trending Min Jiang and Huya faults and the ENE-trending Maowen-Wenchuan, Beichuan and Pengguan faults. The latter are exposed for hundreds of kilometers within the Longman Shan proper. Less well-known but probably equally significant is the NNE-trending Dayi fault, which lies at and partly defines the edge of the Chengdu basin, the western subbasin of the Sichuan Basin. The Huya Valley fault marks the eastern boundary of the N-S trending Min Shan, and is generally mapped as a west-dipping thrust. Observations and inspection of aerial photographs over a distance of ~30 km reveals a prominent N to NNW trending fault that offsets a channel sinistrally by ~100m. The Beichuan fault, near Beichuan, comprises three distinct ENE-trending en echelon segments. Channel and ridge offsets show clear evidence for sinistral displacement. The fault is well expressed across the youngest terrace ~4m above the modern river and likely of Holocene age. A minor thrust component is visible along part of the fault, but the overall expression is predominantly strike-slip. The Pengguan fault is observed immediately north of An Xian where it crosses a Holocene floodplain and is expressed as a ~2m high north-up scarp trending ENE. A sag pond has developed in response to a right-bend, indicating dextral displacement. We observed the same fault (its connection evident on satellite imagery) ~170 km farther southwest, near Shuanghe. The fault is marked here by prominent 15m-high pressure and shutter ridges, offset channels, and linear scarps across both low (Holocene?) and high fluvial terraces. Displacement is unquivocally dextral and predominantly strike-slip. The Dayi fault, ~5 km north of Dayi, is expressed by at least three dextral channel offsets and associated shutter ridges. Exposures of the Pliocene-Quaternary Dayi conglomerate show easterly verging folds and minor fault zones that may reflect active deformation. The geomorphic expression of these faults suggests to us that they young, or slip rates increase, toward the Sichuan Basin. These observations are consistent with those from our earlier reconnaissance field work and taken together show that deformation of the Longmen Shan is currently dominated by crustal-scale conjugate strike-slip faults.

Li, Y.; Ellis, M. A.; Densmore, A. L.; Zhou, R.

2001-12-01

323

Fault interaction near Hollister, California  

NASA Astrophysics Data System (ADS)

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

Mavko, Gerald M.

1982-09-01

324

Fault interaction near Hollister, California  

SciTech Connect

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

Mavko, G.M.

1982-09-10

325

The late early Miocene Sabine River  

SciTech Connect

Work on a new late early Miocene vertebrate fossil site, in a paleochannel deposit of the upper Carnahan Bayou Member of the lower Fleming Formation, has revealed unexpected data on the course and nature of the Sabine River of that time. Screen washing for smaller vertebrate remains at the site, just west of the Sabine River in Newton County, central eastern Texas, has resulted in the recovery of early Permian, Early Cretaceous, Late Cretaceous (Maestrichtian), Paleocene/Eocene, late Eocene, and Oligocene/Miocene fossils, in addition to the main early Miocene fauna. The reworked fossils, as well as distinctive mineral grains, show that the late early Miocene Sabine River was connected to the Texas/Oklahoma/Arkansas boundary section of the Red River, as well as to rivers draining the southern Ouachita Mountains. These rivers must have joined the Texas/Louisiana boundary section of the Sabine River somewhere in northwest Louisiana at that time. This suggests that the Louisiana section of the present Red River pirated the Texas/Oklahoma/Arkansas boundary section of the river some time after the early Miocene. The preservation of recognizable fossils transported hundreds of miles in a large river itself requires explanation. It is speculated here that the late early Miocene Sabine River incorporated a large amount of the then recently deposited volcanic ash from the Trans-Pecos Volcanic Field. Montmorillonite clay from the altered volcanic ash would have made the river very turbid, which could have allowed coarse sand-sized particles to be carried in the suspended load of the river, rather than in its bed load (where they would have been destroyed by the rolling chert gravel). Additional evidence for such long-distance fossil transport in the late early Miocene rivers of the western Gulf Coastal Plain comes from the abundant Cretaceous fossils of the upper Oakville Formation of southeast Texas and the Siphonina davisi zone of the southeast Texas subsurface.

Manning, E. (Louisiana State Univ., Baton Rouge (USA))

1990-09-01

326

Assessment of the fault segmentation and strain accumulation in the northern Longitudinal Valley fault of eastern Taiwan by PS-InSAR with ALOS images  

NASA Astrophysics Data System (ADS)

Taiwan is located at the boundary between the Eurasian Plate and the Philippine Sea Plate. The Longitudinal Valley at the eastern Taiwan is considered to be the collision boundary. There are several faults in the valley and the most famous one is the Longitudinal Valley Fault (LVF) which accommodates about one third of convergence rate between these two plates. LVF is also a seismically active fault zone which ruptured four segments of LVF in 1951 Hualien-Taitung earthquake sequences. Therefore, we want to know the spatial distribution of interseismic strain accumulation along the Longitudinal Valley to access the seismic hazard in different fault segments. To address this problem, we apply a Persistent Scatterer SAR interferometry approach (StaMPS) using L-band ALOS data in eastern Taiwan. The result shows a considerable improvement of measurement's density compared to previous studies using C-band ERS data. The high density of measurement allows us to map the faults trace accurately and get a continuous view of active deformation. The reference area we choose is located in the township of Juisui. All plots in this study are referenced to the mean value for this area. From Hualian river mouth to Nanfu, there is no clear velocity offset along the radar line of sight (LOS) across the Linding fault. It may indicate a shallow or completely locked fault. However, the PSI result shows a local LOS velocity decrease between the latitude of 23'44'' to 23'51'' on both sides of the fault and on Coastal Range. Above the latitude of 23'44'', the LOS velocity is distributed from 10 to -5 mm/yr. The velocity drops to 5 ~ -10 mm/yr southward and then increases to the similar value above 23'44''N. From Nanfu to Chunri, there are two active faults, namely, the Juisui and Chimei faults. The Juisui fault is part of the LVF, and the Chimei fault is located in Coastal Range. From the PSI result, the offset of LOS velocity across the Juisui fault is not clear, too, but we detect a velocity offset (about 10 mm/yr) 2 km east of the fault trace from Central Geological Survey. The LOS velocity in Coastal Range in this area is distributed from 10 to 20 mm/yr toward the satellite which differs from the velocity along the LV and may be related to the activity of the Chimei fault. South of Chunri, the PS result shows a similar pattern to the previous paper which processes ALOS data as well.

Liao, Yu-Tzu; Hu, Jyr-Ching; Champenois, Johann; Pathier, Erwan

2013-04-01

327

Normal fault corrugation: implications for growth and seismicity of active normal faults  

Microsoft Academic Search

Large normal faults are corrugated. Corrugations appear to form from overlapping or en échelon fault arrays by two breakthrough mechanisms: lateral propagation of curved fault-tips and linkage by connecting faults. Both mechanisms include localized fault-parallel extension and eventual abandonment of relay ramps. These breakthrough mechanisms produce distinctive hanging wall and footwall geometries indicative of fault system evolution. From such geometries,

David A Ferrill; John A Stamatakos; Darrell Sims

1999-01-01

328

Parsifal: A Generic and Configurable Fault Emulation Environment with Non-Classical Fault Models  

Microsoft Academic Search

Fault emulation has become an important tool for test evaluation. However, until now fault models other than the stuck-at fault model have rarely been used in emulation. In this paper, we propose non-classical fault models for emulation and a generic fault emulation environment capable of supporting these and other fault models and different emulation modes in a common support framework.

Jan Torben Weinkopf; Klaus Harbich; Erich Barke

2006-01-01

329

Dynamics of earthquake faults  

SciTech Connect

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

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

1994-04-01

330

Fault Branching and Rupture Directivity  

NASA Astrophysics Data System (ADS)

Can the rupture directivity of past earthquakes be inferred from fault geometry? Nakata et al. [J. Geogr., 1998] propose to relate the observed surface branching of fault systems with directivity. Their work assumes that all branches are through acute angles in the direction of rupture propagation. However, in some observed cases rupture paths seem to branch through highly obtuse angles, as if to propagate ``backwards". Field examples of that are as follows: (1) Landers 1992. When crossing from the Johnson Valley to the Homestead Valley (HV) fault via the Kickapoo (Kp) fault, the rupture from Kp progressed not just forward onto the northern stretch of the HV fault, but also backwards, i.e., SSE along the HV [Sowers et al., 1994, Spotila and Sieh, 1995, Zachariasen and Sieh, 1995, Rockwell et al., 2000]. Measurements of surface slip along that backward branch, a prominent feature of 4 km length, show right-lateral slip, decreasing towards the SSE. (2) At a similar crossing from the HV to the Emerson (Em) fault, the rupture progressed backwards along different SSE splays of the Em fault [Zachariasen and Sieh, 1995]. (3). In crossing from the Em to Camp Rock (CR) fault, again, rupture went SSE on the CR fault. (4). Hector Mine 1999. The rupture originated on a buried fault without surface trace [Li et al., 2002; Hauksson et al., 2002] and progressed bilaterally south and north. In the south it met the Lavic Lake (LL) fault and progressed south on it, but also progressed backward, i.e. NNW, along the northern stretch of the LL fault. The angle between the buried fault and the northern LL fault is around -160o, and that NNW stretch extends around 15 km. The field examples with highly obtuse branch angles suggest that there may be no simple correlation between fault geometry and rupture directivity. We propose that an important distinction is whether those obtuse branches actually involved a rupture path which directly turned through the obtuse angle (while continuing also on the main fault), or rather involved arrest by a barrier on the original fault and jumping [Harris and Day, JGR, 1993] to a neighboring fault on which rupture propagated bilaterally to form what appears as a backward-branched structure. Our studies [Poliakov et al., JGR in press, 2002; Kame et al, EOS, 2002] of stress fields around a dynamically moving mode II crack tip show a clear tendency to branch from the straight path at high rupture speeds, but the stress fields never allow the rupture path to directly turn through highly obtuse angles, and hence that mechanism is unlikely. In contrast, study of fault maps in the vicinity of the Kp to HV fault transition [Sowers et al., 1994], discussed as case (1) above, strongly suggest that the large-angle branching occurred as a jump, which we propose as the likely general mechanism. Implications for the Nakata et al. [1998] aim of inferring rupture directivity from branch geometry is that this will be possible only when rather detailed characterization (by surface geology, seismic relocation, trapped waves) of fault connectivity can be carried out in the vicinity of the branching junction, to ascertain whether direct turning of the rupture path through an angle, or jumping and then propagating bilaterally, were involved in prior events. They have opposite implications for how we would associate past directivity with a (nominally) branched fault geometry.

Dmowska, R.; Rice, J. R.; Kame, N.

2002-12-01

331

Making Byzantine Fault Tolerant Systems Tolerate Byzantine Faults  

Microsoft Academic Search

This paper argues for a new approach to building Byzan- tine fault tolerant replication systems. We observe that although recently developed BFT state machine replica- tion protocols are quite fast, they don't tolerate Byzantine faults very well: a single faulty client or server is capa- ble of rendering PBFT, Q\\/U, HQ, and Zyzzyva virtually unusable. In this paper, we (1)

Allen Clement; Edmund L. Wong; Lorenzo Alvisi; Michael Dahlin; Mirco Marchetti

2009-01-01

332

A Probabilistic Fault Detection Approach: Application to Bearing Fault Detection  

Microsoft Academic Search

This paper introduces a method to detect a fault associated with critical components\\/subsystems of an engineered system. It is required, in this case, to detect the fault condition as early as possible, with specified degree of confidence and a prescribed false alarm rate. Innovative features of the enabling technologies include a Bayesian estimation algorithm called par- ticle filtering, which employs

Bin Zhang; Chris Sconyers; Carl Byington; Romano Patrick; Marcos E. Orchard; George Vachtsevanos

2011-01-01

333

Late Quaternary alluviation and offset along the eastern Big Pine fault, southern California  

NASA Astrophysics Data System (ADS)

Determining late Quaternary offset rates on specific faults within active mountain belts is not only a key component of seismic hazard analysis, but sheds light on regional tectonic development over geologic timescales. Here we report an estimate of dip slip rate on the eastern Big Pine oblique-reverse fault in the upper Cuyama Valley within the western Transverse Ranges of southern California, and its relation to local landscape development. Optically stimulated luminescence (OSL) dating of sandy beds within coarse-grained alluvial deposits indicates that deposition of alluvium shed from the Pine Mountain massif occurred near the southern margin of the Cuyama structural basin at the elevation of the Cuyama River between 25 and 14 ka. This alluvial deposit has been offset ˜ 10 m vertically by the eastern Big Pine fault, providing a latest Quaternary dip slip rate estimate of ˜ 0.9 m/ky based on a 50° fault dip. Incision of the adjacent Cuyama River has exposed a section of older Cuyama River sediments beneath the Pine Mountain alluvium that accumulated between 45 and 30 ka on the down-thrown footwall block of the eastern Big Pine fault. Corroborative evidence for Holocene reverse-slip on the eastern Big Pine fault is ˜ 1 m of incised bedrock that is characteristically exposed beneath 2 3.5 ka fill terraces in tributaries south of the fault. The eastern Big Pine fault in the Cuyama Valley area has no confirmed record of historic rupture; however, based on our results, we suggest the likelihood of multiple reverse-slip rupture events since 14 ka.

Delong, Stephen B.; Minor, Scott A.; Arnold, Lee J.

2007-10-01

334

What lies below the Columbia River Basalt?  

NASA Astrophysics Data System (ADS)

More than 200,000 sq km of the Pacific Northwest are covered by the Miocene Columbia River Basalt Group (CRB). The lavas were erupted onto a complex structural setting dominated by cratonic rocks, and accreted terranes at a convergent plate margin. Few boreholes penetrate the basalt so the sub-basalt structure must be deduced from geophysical data, the surrounding area and structures within the basalt. In Oregon (OR) and Idaho (ID) the eastern edge of the basalt follows the boundary between the craton and accreted terranes but the suture zone becomes lost beneath the basalt in eastern WA. In northern OR and Washington (WA), a thick basalt sequence in the western part of the province overlies an early Tertiary basin with kms of sediment fill which, in turn, overlies accreted terranes. In eastern WA and western ID, a much thinner basalt sequence overlies cratonic and accreted terrane rocks without thick intervening Tertiary sediments. This basin began in the Eocene and continued into the present; the sediment now controls the location of the Yakima fold belt (YFB). Prior to basalt eruptions, a rugged mountainous terrane existed in eastern WA and ID that probably extended to the west. NW faults and folds (e.g. the Orofino fault zone ID, and Chiwaukum graben and White River-Naches River fault zone, Cascade Range) dominate the prebasalt rocks and must extend under the basalt. Remanents of this NW trend are present in YFB (e.g. Rattlesnake-Wallula fault zone) but these are less prominent than the large basalt anticlinal folds that are decoupled from the basement. CRB dikes have a NW to N trend and are thought to reflect a basement structural weakness. In the basalt province many folds and faults follow this dike trend. Major NE trending faults in the basalts do not have major counterparts beyond the basalt. One fault, the Hite Fault, must form a significant sub-basalt boundary. Dikes to the east of the Hite fault trend N-N20W whereas dikes to the west trend N40-50W, suggesting a major fault separating two fundamental basement structural zones. Overall, basement structures have had a significant influence on the tectonic development of the flood-basalt province and may help explain why 75 percent of the basalt occurs in the northern part of the province.

Reidel, S.; Kauffman, J.; Garwood, D.; Bush, J.

2006-12-01

335

Late Quaternary slip rate on the Oak Ridge fault, Transverse Ranges, California: Implications for seismic risk  

NASA Astrophysics Data System (ADS)

The slip rate on the Oak Ridge fault at South Mountain in the densely populated lower Santa Clara Valley, California, is estimated as 5.9-12.5 mm/yr since the end of Saugus deposition at 0.4-0.2 Ma. A displacement of 3 m per event, assumed on the basis of surface rupture on the 1952 Kern County, 1971 San Fernando, and 1978 Tabas-e-Golshan earthquakes, gives an average recurrence interval of 250-500 years, with the major uncertainty being the age of the top of the Saugus. Displacement of 2375-2490 m of the top of the Saugus at South Mountain includes piercing-point displacement and distributed displacement from drag folds near the fault; both are the near-surface expression of faulting at potential main shock depths beneath well control. Slip rates for the nearby San Cayetano and Red Mountain faults are less well constrained because post-Miocene strata are largely absent in their hanging-wall blocks, but available evidence suggests that their slip rates are in the same range as that for the Oak Ridge fault. The lower Santa Clara Valley has not had a large, damaging earthquake in 200 years of record keeping, although the December 21, 1812, tsunami-producing earthquake could have occurred on the offshore continuation of the Oak Ridge or Red Mountain fault. A trench on the Harmon alluvial fan near the Ventura County Government Center revealed evidence of cracks filled with sediments from below, suggesting liquefaction during a Holocene earthquake. Earthquake repeat times measured in hundreds of years have been reported by others for the 1971 San Fernando fault and a small fault near the Red Mountain fault, and comparable repeat times are suggested for a normal fault within the hanging-wall block of the Oak Ridge fault. These are consistent with the average recurrence interval calculated for the Oak Ridge fault, suggesting that a destructive earthquake may strike the lower Santa Clara Valley in the near future.

Yeats, Robert S.

1988-10-01

336

Reinterpretation of faulting in southeast Missouri  

Microsoft Academic Search

New observations are presented on the character of Late Proterozoic-Early Cambrian, rift-related faulting in southeast Missouri. The principal fault set, which influences southeast Missouri structures, is composed of northwest-striking transfer faults. Initial Late Cambrian reactivations extended the faults northwest across the mid-continent and formed several major lineaments. Transpressive wrench-fault reactivations of these faults during Late Pennsylvanian-Early Permian time uplifted the

C. W. Clendenin; C. A. Niewendorp; G. R. Lowell

1989-01-01

337

Fault Models for Quantum Mechanical Switching Networks  

Microsoft Academic Search

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

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

2010-01-01

338

Fault Tolerant Remote Procedure Call  

Microsoft Academic Search

A scheme is presented that makes a remote procedure call (RPC) mechanism fault-tolerant to hardware failures. Fault tolerance is provided by replicating the procedure at a group of nodes, called a cluster. The copies in a cluster are linearly ordered. A call to a procedure is sent to the first copy in the cluster and is propagated internally to all

Kiam S. Yap; Pankaj Jalote; Satish K. Tripathi

1988-01-01

339

Game Theoretic Fault Detection Filter.  

National Technical Information Service (NTIS)

The fault detection process is modeled as a disturbance attenuation problem. The solution to this problem is found via differential game theory, leading to an H(sub infinity) filter which bounds the transmission of all exogenous signals save the fault to ...

W. H. Chung J. L. Speyer

1995-01-01

340

A Novel Fault Current Limiter  

Microsoft Academic Search

Although many attempts have been made to construct an economically feasible Fault Current Limiter (FCL), no FCL has yet been widely accepted by the power industry. This thesis presents a novel fault current limiter for power system applications that is both economically feasible and practical. The work includes two parts. The first part proposes the new topology and analyzes the

Andrew Leo Otete

2004-01-01

341

Uncertainties in Fault Tree Analysis  

Microsoft Academic Search

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

Yue-Lung Cheng

342

DC superconducting fault current limiter  

Microsoft Academic Search

There is a lack of satisfying solutions for fault currents using conventional technologies, especially in DC networks, where a superconducting fault current limiter could play a very important part. DC networks bring a lot of advantages when compared to traditional AC ones, in particular within the context of the liberalization of the electric market. Under normal operation in a DC

P. Tixador; C. Villard; Y. Cointe

2006-01-01

343

DAFT: decoupled acyclic fault tolerance  

Microsoft Academic Search

Higher transistor counts, lower voltage levels, and reduced noise margin increase the susceptibility of multicore processors to transient faults. Redundant hardware modules can detect such errors, but software transient fault detection techniques are more appealing for their low cost and flexibility. Recent software proposals double register pressure or memory usage, or are too slow in the absence of hardware extensions,

Yun Zhang; Jae W. Lee; Nick P. Johnson; David I. August

2010-01-01

344

Fault trees and imperfect coverage  

Microsoft Academic Search

A new algorithm is presented for solving the fault tree. The algorithm includes the dynamic behavior of the fault\\/error handling model but obviates the need for the Markov chain solution. As the state space is expanded in a breadth-first search (the same is done in the conversion to a Markov chain), the state's contribution to each future state is calculated

Joanne Bechta Dugan

1989-01-01

345

Surface Creep on California Faults  

NSDL National Science Digital Library

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

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

346

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

347

Paleoseismological Trenching Across The Eliki and Aigion Faults (gulf of Corinth, Greece)  

NASA Astrophysics Data System (ADS)

Paleoseismological trenching in the Aigion area started in 1998 along the portion of the East Eliki fault that ruptured during the 1861 earthquake Thanks to the EC funded CORSEIS project more trenching was performed both across the Elike fault and new was started along the Aigion fault. Both faults present a very clear geomorphology, typical of normal faults and some internal complexity with fault sections arranged in a right en-echelon pattern. The East Eliki fault was trenched between the village of Diakophto and the Kerinites river and a total of seven trenches have been opened by different groups at four sites. Here we present the results obtained at two of these sites where we found evidence for at least two events during the past 2000 years, pre- dating the 1861 earthquake. More dating is underway to better constrain the ages of individual surface faulting events. Coseismic slip can only be estimated as a minimum because the fault footwall exposed in the trenches is always in bedrock thus, no direct measurement of the total net displacement can be performed. A minimum of ca. 0.5 m is estimated at all sites based on displacements on secondary faults and thickness of colluvial wedges. The Aigion fault was studied at two sites. The first site is located west of the town of Aigion close to the national road. Here a huge cut (now destroyed) across the hanging wall of the Aigion fault exposed a 5 m-thick sequence of colluvium in tectonic contact with Pleistocene fan-delta deposits (the local bedrock). Secondary faults displace the colluvial sequence possibly up to a layer as young as 1600 A.D. Severe human modification of the upper part of the section does not allow a clear definition of the most recent important event of surface faulting. The second site is just east of the village of Agios Kostantinos, at a location where some cracks and a few centimeter displacement occurred during the 1995, M6.2 earthquake. At this site a trench and a 6 m deep core exposed fluvial overbank deposits displaced against pond deposits up to 5 m thick. Evidence for two surface faulting events substantially larger than the 1995 one was found. Dating is underway to constrain both the age of the events and the rate or slip on this part of the Aigion fault.

Pantosti, D.; de Martini, P. M.; Koukouvelas, I.; Stamatopoulos, L.; Pavlides, S.; Palyvos, N.; Pucci, S.

348

Symmetry properties, pulverized rocks and damage architecture in fault zones as signatures of earthquake ruptures  

NASA Astrophysics Data System (ADS)

Structural symmetry properties were mapped across faults of the San Andreas Fault (SAF) and North Anatolian Fault (NAF) systems, at various scales and several sites on each fault. Fractures on a fault-core scale, subsidiary faults and fault rocks on a fault-zone scale and pulverized rocks on a damage-zone scale show systematically asymmetry. On the SAF, San Jacinto and Punchbowl faults the northeast side is more damaged. On the NAF 1943 and 1944 rupture sections the south and north sides, respectively, are more damaged. Asymmetric erosion patterns along the NAF including locations of river valleys with respect to the fault and contrast in drainage density and other morphometric parameters across the fault, are consistent with the geologically mapped structural asymmetry. These asymmetric patterns are compatible with preferred rupture directions northwestward on faults of the SAF system, and eastward and westward on the 1943-1944 rupture sections of the NAF, respectively (as occurred in these two earthquakes). Tomographic studies show that the northeast side of the SAF and the San Jacinto fault have faster seismic velocities at depth. Significant damage content in sedimentary rocks of the Juniper Hills formation near the SAF in the central Mojave section indicates that dynamic generation of damage can occur close to the Earth surface, in agreement with other indications for minimal exhumation of damaged fault zone rocks. An asymmetric shallow damage structure correlated with the velocity structure at depth is a predicted outcome for rupture along a bimaterial interface (Ben-Zion and Shi, 2005). Microfractures in the Juniper Hills rocks near the fault, orientated preferably normal to its strike, are compatible with the transient stress field associated with seismic slip events on frictional rough surfaces (Chester and Chester, 2000). The damage fabric is anisotropic, rich with compressional features, and therefore not compatible with an absolute tension. Structural analysis of orientation and slip data of 115 slip surfaces in the hanging-wall of the Sierra Madre fault near JPL shows that their geometry and kinematics are compatible with Mohr-Coulomb failure associated with the stress field of propagating mode II ruptures with slip weakening (Rice et al. 2005).

Dor, Ory

349

Differential Fault Analysis of Rabbit  

NASA Astrophysics Data System (ADS)

Rabbit is a high speed scalable stream cipher with 128-bit key and a 64-bit initialization vector. It has passed all three stages of the ECRYPT stream cipher project and is a member of eSTREAM software portfolio. In this paper, we present a practical fault analysis attack on Rabbit. The fault model in which we analyze the cipher is the one in which the attacker is assumed to be able to fault a random bit of the internal state of the cipher but cannot control the exact location of injected faults. Our attack requires around 128 - 256 faults, precomputed table of size 241.6 bytes and recovers the complete internal state of Rabbit in about 238 steps.

Kircanski, Aleksandar; Youssef, Amr M.

350

Constraints on the mechanism of the Altyn Tagh fault from paleomagnetism  

Microsoft Academic Search

First, paleomagnetic data were obtained from Tertiary red beds at two localities separated by several hundred kilometers within the Qaidam Basin. When compared with equivalent-age expected directions for Eurasia, the mean paleomagnetic directions indicate no Neogene vertical-axis rotation of the Qaidam Basin or the Altyn Tagh fault. The Qaidam Basin may act as an indentor translating without rotation toward the

Guillaume Dupont-Nivet

2002-01-01

351

Raptor Survey of the Lower Salmon and Snake Rivers.  

National Technical Information Service (NTIS)

Twelve raptor species were recorded during surveys conducted along the Lower Salmon and Snake River canyons, April 2 - April 14, 1993. Golden eagles were the most commonly observed species, followed by red-tailed hawks and American kestrels. Prairie falco...

C. Bradford F. Cassirer

1994-01-01

352

M. Gordon “Reds” Wolman (1924-2010)  

NASA Astrophysics Data System (ADS)

M. Gordon Wolman, known to all as “Reds,” died at his home in Baltimore, Md., on 24 February 2010. He was 85. His career was defined by fundamental contributions to scientists' understanding of rivers, pioneering work in developing interdisciplinary environmental education, and an extraordinary commitment to the application of research to water management and policy. His warmth, affection, and delight inspired generations of students, colleagues, and friends.

Wilcock, Peter

2010-08-01

353

The Pietra Grande thrust (Brenta Dolomites, Italy): looking for co-seismic indicators along a main fault in carbonate sequences  

NASA Astrophysics Data System (ADS)

At present, pseudotachylytes (i.e. solidified frictional melts) are the only unambiguous geological record of seismic faulting. Even if pseudotachylytes are frequently observed along faults within crystalline rocks they are discovered along carbonate faults in very few cases only, suggesting that other chemico-physical processes than melting could occur (e.g. thermal decomposition). In order to investigate possible co-seismic indicators we study the Pietra Grande thrust, a carbonate fault in the Brenta Dolomites (Trentino, NE Italy), to analyse field structure, microtextures and composition of rocks from the principal slip plane, the fault core and the damage zone. The Pietra Grande thrust is developed within limestones and dolomitic limestones of Late Triassic-Early Jurassic age (Calcari di Zu and Monte Zugna Formations). The thrust, interpreted as a north-vergent décollement deeply connected with the major Cima Tosa thrust, is a sub-horizontal fault plane gently dipping to the North that mainly separates the massive Monte Zugna Fm. limestones (upper side) from the stratified Calcari di Zu Fm. limestones with intercalated marls (lower side). On the western face of the Pietra Grande klippe the thrust is continuously well-exposed for about 1 km. The main fault plane shows reddish infillings, which form veins with thicknesses between few millimetres to several decimetres. These red veins lie parallel to the thrust plane or in same cases inject lateral fractures and minor high-angle faults departing from the main fault plane. Veins have carbonate composition and show textures characterized by fine-grained reddish matrix with embedded carbonate clasts of different size (from few millimetres to centimetres). In some portions carbonate boulders (dimension of some decimetres) are embedded in the red matrix, while clast content generally significantly decreases at the vein borders (chilled margins). Red veins are typically associated with cohesive cataclasites and/or breccias of the fault zone. Host and fault rocks are locally folded, with fold axes having a rough E-W direction compatible with simultaneous thrust activation, suggesting deformation under brittle-ductile conditions. A late brittle deformation is testified by near-vertical fractures and strike-slip faults (WNW-directed) intersecting the whole thrust system. Field structure, microtextures, chemical and mineralogical compositions of host rocks, cataclasites and breccias are analysed. In particular, red veins are carefully compared with the very similar Grigne carbonate pseudotachylytes (Viganò et al. 2011, Terra Nova, vol. 23, pp.187-194), in order to evaluate if they could represent a certain geological record of seismic faulting of the Pietra Grande thrust.

Viganò, Alfio; Tumiati, Simone; Martin, Silvana; Rigo, Manuel

2013-04-01

354

Mesozoic-Cenozoic evolution of the intraplate Euphrates fault system, Syria: implications for regional tectonics  

Microsoft Academic Search

A lack of dramatic surface geological structures along the Euphrates River in Syria belie a complex tectonic history revealed by newly released seismic reflection and well data. We document the intraplate Euphrates fault system, characterize the variation in structural style along its 350 km length in Syria, and infer its Mesozoic-Cenozoic tectonic and deformational history. We then relate the defor-

ROBERT K. LITAK; MUAWIA BARAZANGI; WELDON BEAUCHAMP; DOGAN SEBER; GRAHAM BREW; TARIF SAWAF; WASIF AL-YOUSSEF

1997-01-01

355

Characterization of fractures in limestones - northern segment of Edwards aquifer and Balcones fault zone, central Texas  

SciTech Connect

Fracture distributions, orientations, and densities in Comanche Peak, Edwards, and Georgetown limestones (Edwards aquifer strata) were determined in conjunction with geologic mapping near the San Gabriel River from Lake Georgetown to Weir, Texas, to increase the understanding of the geology of the Balcones fault zone and to provide data useful in identification of potential recharge areas and assessment of local ground-water flow.

Collins, E.W.

1987-09-01

356

Arc fault detection system  

DOEpatents

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

Jha, K.N.

1999-05-18

357

Evaluate Status of Pacific Lamprey in the Clearwater River and Salmon River Drainages, Idaho, 2009 Technical Report.  

SciTech Connect

Pacific lamprey Lampetra tridentata have received little attention in fishery science until recently, even though abundance has declined significantly along with other anadromous fish species in Idaho. Pacific lamprey in Idaho have to navigate over eight lower Snake River and Columbia River hydroelectric facilities for migration downstream as juveniles to the Pacific Ocean and again as adults migrating upstream to their freshwater spawning grounds in Idaho. The number of adult Pacific lamprey annually entering the Snake River basin at Ice Harbor Dam has declined from an average of over 18,000 during 1962-1969 to fewer than 600 during 1998-2006. Based on potential accessible streams and adult escapement over Lower Granite Dam on the lower Snake River, we estimate that no more than 200 Pacific lamprey adult spawners annually utilize the Clearwater River drainage in Idaho for spawning. We utilized electrofishing in 2000-2006 to capture, enumerate, and obtain biological information regarding rearing Pacific lamprey ammocoetes and macropthalmia to determine the distribution and status of the species in the Clearwater River drainage, Idaho. Present distribution in the Clearwater River drainage is limited to the lower sections of the Lochsa and Selway rivers, the Middle Fork Clearwater River, the mainstem Clearwater River, the South Fork Clearwater River, and the lower 7.5 km of the Red River. In 2006, younger age classes were absent from the Red River.

Cochnauer, Tim; Claire, Christopher [Idaho Department of Fish and Game

2009-05-07

358

BALD ROCK AND MIDDLE FORK FEATHER RIVER ROADLESS AREAS, CALIFORNIA.  

USGS Publications Warehouse

The results of a mineral-resource assessment of the Bald Rock and Middle Fork Feather River Roadless Areas in California indicate several areas within the Middle Fork Feather River Roadless Area that have probable mineral-resource potential. A probable potential for placer gold exists at various localities, both in areas covered by Tertiary volcanic rocks and in small streams that drain into the Middle Fork of the Feather River. A probable potential for small deposits of chromite exists in tracts underlain by ultramafic rocks in the Melones fault zone. A probable potential for lead-silver deposits is recognized at the east end of the Middle Fork Feather River Roadless Area.

Sorensen, Martin, L.; Buehler, Alan, R.

1984-01-01

359

Structure and seismic hazard of the Ventura Avenue anticline and Ventura fault, California  

NASA Astrophysics Data System (ADS)

The Ventura Avenue anticline, in the western Transverse Ranges, is one of the fastest uplifting structures in southern California, rising at a rate of ~5 mm/yr (Rockwell et al., 1988). However, there is disagreement about whether this structure poses a seismic hazard, due to uncertainty about the nature of the Ventura fault, which lies along the southern margin of the fold. Two models have been proposed: either the Ventura fault extends to seismogenic depths beneath the anticline (e.g., Sarna-Wojcicki et al., 1976), or it is a shallow, bending-moment fault that does not pose a significant seismic hazard (e.g., Yeats, 1982a,b; Huftile and Yeats, 1995). Seismic data across the tip of the Ventura fault suggest that it deforms late Pleistocene and younger strata, implying that the fault system is active. Given that the fault trace extends directly through the city of Ventura, distinguishing between these two interpretations has considerable importance in regional seismic hazard assessments. We use well data, industry seismic reflection profiles, and two seismic profiles acquired by our group in August 2010, to construct a more complete 3D model of the system. Based on dipmeter logs and stratigraphic cutoffs imaged in seismic reflection profiles, we show that the north-dipping Ventura fault extends to seismogenic depth beneath the anticline. Fault offset increases with depth, implying that the Ventura fault has propagated upwards over time. Thus, we interpret the Ventura Avenue anticline to be a fault-propagation fold underlain by an active thrust ramp. A decrease in the uplift rate of the anticline at 30 ka, as measured from uplifted terraces (Rockwell et al., 1988), is consistent with a breakthrough of the Ventura fault at that time, although the fault is still blind as it is buried by a sedimentary cover. In order to assess the hazard of the fault, we examine its regional extent. The Ventura fold trend continues offshore and coincides with a set of oil fields. A 3D seismic dataset across the Dos Cuadras field, which lies along the trend, shows that it is a fault-propagation fold, structurally similar to the Ventura Avenue anticline. Dos Cuadras is also underlain by a north-dipping thrust fault, known as the Pitas Point thrust. Based on our and others' mapping, the Ventura and Pitas Point faults form an en echelon system that extends at least 40 km offshore. Other regional faults, including the San Cayetano, Lion, and Red Mountain faults, link with the Ventura/Pitas Point system at depth; we suggest that at 15 km depth, these faults may all link into a single, continuous fault surface. One of the greatest hazards in fold-and-thrust belts is the risk of large, multi-segment ruptures. Linkage of the Ventura/Pitas Point fault could generate a M7.3 earthquake, while rupture in association with other regional faults could produce even larger events. We provide 3D models of these faults and estimate the magnitudes of potential multi-segment earthquakes. Finally, we show that GPS data are consistent with a very high shortening rate (> 6 mm/yr) across the anticline, reinforcing the hazardous nature of the system.

Hubbard, J.; Shaw, J. H.; Dolan, J. F.; Pratt, T. L.; McAuliffe, L. J.

2011-12-01

360

Evaluate Status of Pacific Lamprey in the Clearwater River Drainage, Idaho, Annual Report 2002.  

SciTech Connect

In 2002 Idaho Department of Fish and Game continued investigation into the status of Pacific lamprey populations in Idaho's Clearwater River drainage. Trapping, electrofishing, and spawning ground redd surveys were used to determine Pacific lamprey distribution, life history strategies, and habitat requirements in the South Fork Clearwater River, Lochsa River, Selway River, and Middle Fork Clearwater River subbasins. Five-hundred forty-one ammocoetes were captured electroshocking 70 sites in the South Fork Clearwater River, Lochsa River, Selway River, Middle Fork Clearwater River, Clearwater River, and their tributaries in 2002. Habitat utilization surveys in Red River support previous work indicating Pacific lamprey ammocoete densities are greater in lateral scour pool habitats compared to riffles and rapids. Presence-absence survey findings in 2002 augmented 2000 and 2001 indicating Pacific lamprey macrothalmia and ammocoetes are not numerous or widely distributed. Pacific lamprey distribution was confined to the lower reaches of Red River below rkm 8.0, the South Fork Clearwater River, Lochsa River (Ginger Creek to mouth), Selway River (Race Creek to mouth), Middle Fork Clearwater River, and the Clearwater River (downstream to Potlatch River).

Cochnauer, Tim; Claire, Christopher

2003-10-01

361

The Dead Sea Rift, a key to the tectonic link between the NeoTethys closure of and opening of the Red Sea  

NASA Astrophysics Data System (ADS)

The closure of the central NeoTethys Ocean took place progressively as the subduction of the oceanic lithosphere off Africa-Arabia gradually changed into collision, advancing southeastwards along the Zagros front since the early Miocene. That subduction-collision is contemporaneous with the opening of the Red Sea, and structural modeling suggested that the oblique convergence along frontal Arabia formed extensional stresses in the Arabia-Africa plate which matured in time to become the tectonic plate boundaries of the Gulf of Aden and the Red Sea (Bellahsen et al., 2003). However such marine basins are not known to occur along subducting plates, and the contemporaneity of the Zagros collision and the Red Sea extension could have been tectonically unrelated. Fortuitously the key to the tectonic linkage between the opening of the Red Sea and the closure of the NeoTethys can be found in the Dead Sea Rift. The tectonics of the Dead Sea Rift has been debated for decades to be interpreted either as a transform fault or an extensional rift, both extending from the northern Red Sea. The transform fault interpretation requires the Dead Sea structure to be contemporaneous with the Red Sea, whereas if it is an extensional rift, its structural development should be subsequent to that of the the Suez Rift. It is well established that the Red Sea and its extension in the Suez Rift developed during the Miocene. However, the reconstruction of the Miocene river drainage of the Levant shows that large rivers flowed then from NW Arabia to the Mediterranean, predating the Dead Sea Rift. This sequence of events sets the structural evolution of the dead Sea Rift to the Plio-Quaternary. The Rift is thus contemporaneous with the termination of the tectonic activity of the Gulf of Suez, indicating a clockwise rotation of the regional stress field in the last 5 Ma. These observation suggest that the extensional stresses caused by the gradual change from subduction to collision along the converging tectonic front of Arabia and the Zagros formed extensional domain that affected the propagating Carlsberg Ridge. It is suggested that that extensional domain first caused the change in the direction of the propagation of Carlsberg ridge westwards, to form its NW trend and break open the Gulf of Aden. Clockwise rotation of the stress field diverted the rifting northwestwards to form the Red Sea and the Suez Rift. Another clockwise deflection in the Pliocene shifted the axis of the northern extension of the Red Sea to abandon the Suez Rift and form the Dead Sea Rift. That latter rifting event is thus a product of the conversion of subduction to collision along the southern section of the Zagros-Arabia tectonic convergence. Reference Bellahsen, N., Faccenna, C., Funiciello, F., Daniel J. M. and Jolivet, L., 2003. Why did Arabia separate from Africa? Insights from 3-D laboratory experiments. Earth Planet. Sci. Lett., 216, 365-381

Mart, Y.

2009-04-01

362

Present-day crustal motion along the Carboneras fault in the Betic Cordilleras, Spain  

NASA Astrophysics Data System (ADS)

In December 2008, in the framework of the EVENT project, we have installed a continuous GPS station in several km SW to the village of Rodalquilar, inside the Cabo de Gata-Nijar natural park, with the main objective of monitoring the activity of the Carboneras fault. After analyzing 15 month long time-series we have estimated that the fault in question, is continuing to be active and exhibits mainly left-lateral strike slip motion of 1.5±0.7 mm/yr with a minor compressive component of 1.0±0.7 mm/yr. These findings are in agreement with the estimates of slip rates from onshore-offshore paleoseismic studies. GPS Velocity vectors in mm/yr with 1? errors w.r.t. HUEB station. Red labels depict stations from CuaTeNeo GPS network (see Khazaradze et al. [2008] for more details. CF: Carboneras Fault; CAFZ: Corredor de las Alpujarras Fault Zone.

Khazaradze, G.; Asensio, E.; Moreno, X.; Masana, E.

2010-12-01

363

Inductive Fault Analysis of MOS Integrated Circuits  

Microsoft Academic Search

Inductive Fault Analysis (IFA) is a systematic Procedure to predict all the faults that are likely to occur in MOS integrated circuit or subcircuit The three major steps of the IFA procedure are: (1) generation of Physical defects using statistical data from the fabrication process; (2) extraction of circuit-level faults caused by these defects; and (3) classification of faults types

John Shen; W. Maly; F. J. Ferguson

1985-01-01

364

Sensitivity analysis of modular dynamic fault trees  

Microsoft Academic Search

Dynamic fault tree analysis, as currently supported by the Galileo software package, provides an effective means for assessing the reliability of embedded computer-based systems. Dynamic fault trees extend traditional fault trees by defining special gates to capture sequential and functional dependency characteristics. A modular approach to the solution of dynamic fault trees effectively applies Binary Decision Diagram (BOD) and Markov

Yong Ou; Joanne Bechta Dugan

2000-01-01

365

Creating Small Fault Dictionar-ies  

Microsoft Academic Search

Diagnostic fault simulation can generate enormous amounts of data. The techniques used to manage this data can have signi cant e ect on the outcome of the fault diagnosis procedure. We rst demonstrate that if information is removed from a fault dictionary, its ability to diagnose unmodeled faults may be severely curtailed even if dictionary quality metrics remain una ected;

B. Chess; T. Larrabee

1999-01-01

366

Arc Fault Management Using Solid State Switching  

Microsoft Academic Search

In arc fault circuit breakers, the choice of a fault detection sensitivity is generally made as a compromise between speed of detection and avoidance of nuisance trips. By using solid state switching with a variable arc fault detection threshold, the best of both worlds can be obtained. This paper describes baseline experiments on arc fault management through the use of

David Nemir; Adriana Martinez; Bill Diong

2004-01-01

367

Composite fault location for Distribution Management Systems  

Microsoft Academic Search

The problem of fault location is an integral part of Distribution Management System (DMS) solutions. This paper presents a method of locating fault in unsymmetrical networks, including both radial and meshed parts of the network. The real-time information regarding the topological condition of the network and the status updates of the Fault Indicators are used as input to the fault

I. Dzafic; P. Mohapatra; H. T. Neisius

2010-01-01

368

Fault Propagation Model for Ad Hoc Networks  

Microsoft Academic Search

Emerging technologies of autonomic networks im- pose demanding requirements on self-healing capabilities of networks. Fault management techniques based on the exploitation of fault propagation models (FPM) are a promising solution to conduct fault isolation and to infer the root cause of problems observed in the network. In this study, we investigate a fault prop- agation model developed for the needs

Agnieszka Betkowska Cavalcante; Monika Grajzer

2011-01-01

369

LSI product quality and fault coverage  

Microsoft Academic Search

At present, the relationship between fault coverage of LSI circuit tests and the tested product quality is not satisfactorily understood. Reported work on integrated circuits predicts, for an acceptable field reject rate, a fault coverage that is too high (99 percent or higher). This fault coverage is difficult to achieve for LSI circuits. This paper proposes a model of fault

Vishwani D. Agrawal; Sharad C. Seth; Prathima Agrawal

1981-01-01

370

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

Microsoft Academic Search

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

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

2004-01-01

371

Implications for mechanical properties of brittle faults from observations of the Punchbowl fault zone, California  

Microsoft Academic Search

Field observations of the Punchbowl fault zone, an inactive trace of the San Andreas, are integrated with results from experimental deformation of naturally deformed Punchbowl fault rocks for a qualitative description of the mechanical properties of the fault and additional information for conceptual models of crustal faulting. The Punchbowl fault zone consists of a single, continuous gouge layer bounded by

F. M. Chester; J. M. Logan

1986-01-01

372

Fault diagnosis of airborne equipment based on grey correlation fault tree identification method  

Microsoft Academic Search

In order to diagnosis the complex airborne equipment faults with small samples and feebleness condition, a grey correlation fault tree identification method is proposed by combining the grey system theory with fault tree analysis method. Firstly, on the basis of the fault tree qualitative and quantitative analysis by using binary decision diagram (BDD), the standard fault modes are constructed based

Wei Tian

2008-01-01

373

Fault detection and management system for fault tolerant switched reluctance motor drives  

Microsoft Academic Search

Fault-tolerance characteristics of the switched reluctance motor are discussed, and winding fault detectors are presented which recognize shorted motor windings. Logic circuitry in the inverter blocks the power switch gating signals of the affected phase at the receipt of a fault-detection signal from one of the fault detectors. The fault detectors were implemented on a laboratory drive system to demonstrate

C. M. Stephens

1989-01-01

374

Fault injection in mixed-signal environment using behavioral fault modeling in Verilog-A  

Microsoft Academic Search

Fault injection methods have been used for analyzing dependability characteristics of systems for years. In this paper we propose a practical mixed-signal fault injection flow that is fast as well as accurate. We described three classes of most common faults: i) Single event transients, ii) Electro-Magnetic interference and iii) Power disturbance faults. Fault models are implemented directly into circuit's devices

Seyed-Nematollah Ahmadian; Seyed-Ghassem Miremadi

2010-01-01

375

Holocene kinematics and slip rate of the Sayan fault (Southern Siberia, Russia)  

NASA Astrophysics Data System (ADS)

The Sayan fault is located at the boundary between the northernmost mountain belt of Central Asia (the Sayan-Baikal ranges) and the Siberian platform. This outstanding ~ 500 km crustal structure defines an obvious and sharp morphotectonics feature easily recognizable on satellite imagery. Inherited from the Palaeozoic orogenes, the Sayan fault has been working as a left-lateral transform fault during the opening of the Baikal Rift in the Cainozoic time. Despite a very low instrumental seismic activity and few historical earthquakes, Holocene morphotectonics features along the fault attests of its activity and its capacity of producing strong earthquakes. The Sayan fault represents therefore a strong hazard for the city of Irkoutsk, which is located 70 km northwards of its south-eastern tip, and where more than one million people are living. In order to quantify the present kinematics of the fault, to estimate its slip rate and the potential magnitude of earthquakes, we carried out a morphotectonics study within its south-eastern part, between the Baikal Lake and the Irkut River (the only part of the fault relatively accessible, while further west the fault stands in a mountainous area covered with dense forest without any easy access). A reconnaissance trip allowed us finding out a small catchment basin cut by the fault and showing a cumulative offset of several tens of meters. We surveyed the site with a total station to produce a Digital Elevation Model, and we collected samples of the offset surface and the trapped sediments for radiocarbon and OSL dating. In progress analyses should allow us to provide a first estimate of the left-lateral slip rate along the Sayan fault.

Ritz, J.-F.; Larroque, C.; Vassallo, R.; Arzhannikova, A.; Arzhannikov, S.; Jolivet, M.

2012-04-01

376

Mariculture of Red Seaweeds.  

National Technical Information Service (NTIS)

As new applications for using red seaweed have developed, the demand for red seaweed has increased, to the point where commercial harvesting techniques now need to be developed to lessen dependence on wild seaweed stocks. The history of red seaweed use as...

J. E. Hansen J. E. Packard W. T. Doyle

1981-01-01

377

Red Owl's Legacy  

Microsoft Academic Search

In the early 1960s, Joseph Hoffman, a high school graduate, baker and father of seven, sought to obtain a Red Owl grocery store franchise in Wisconsin. He entered into negotiations with Red Owl Stores, Inc. after the franchisor assured him that the $18,000 he had to invest in the franchise was sufficient. Over the course of the negotiations, Red Owl

Gregory M Duhl

2003-01-01

378

Fault Trace: Marin County, California  

NSDL National Science Digital Library

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

379

International Rivers  

NSDL National Science Digital Library

International Rivers is an organization that opposes the construction of destructive dams on rivers, and they also support communities affected by dams. Their aim is to "protect rivers and promote just and sustainable water and energy development." Visitors will find most of their questions about dams and hydroelectricity can be answered under the "Learn More" tab's FAQ section. Along with each answer, there is most often an article, slideshow, video or other resource to explore further. Some of the pieces examine why there is opposition to large dams, the expense of hydroelectricity, the lack of local jobs produced when a dam is being built in a developing country, and the number of people displaced by dams. Under the "Get Involved" tab, there is a section called "Tools for Educators" that include lessons for introductory learners, intermediate learners, advanced learners, and a "River Educator's Toolkit", which contains lessons on the four major rivers in Asia, Africa, and South America.

380

DAFT: Decoupled Acyclic Fault Tolerance  

Microsoft Academic Search

Higher transistor counts, lower voltage levels, and reduced noise margin increase the susceptibility of multicore processors\\u000a to transient faults. Redundant hardware modules can detect such faults, but software techniques are more appealing for their\\u000a low cost and flexibility. Recent software proposals have not achieved widespread acceptance because they either increase register\\u000a pressure, double memory usage, or are too slow in

Yun Zhang; Jae W. Lee; Nick P. Johnson; David I. August

381

Generic faults - The first word  

NASA Astrophysics Data System (ADS)

The achievement of highly reliable, full time critical control system designs, such as those of fly-by-wire and fly-by-light flight control systems, is through the institution of development methods which increase the likelihood of faults' detection and toleration by redundant system architectural practices and reconfiguration capabilities. Management methods must accordingly give attention to factors that can be computed to act as predictors of fault and error performance on the basis of physical data.

Cannon, D. G.

382

Types of Faults in California  

NSDL National Science Digital Library

This educational movie made using SCEC-VDO shows the differences between strike-slip faults and thrust faults in southern California.The Southern California Earthquake Center's Virtual Display of Objects SCEC-VDO is 3D visualization software that allows users to display study and make movies of earthquakes as they occur globally. SCEC-VDO was developed by interns of SCEC Undergraduate Studies in Earthquake Information Technology UseIT under the supervision of Sue Perry and Tom Jordan.

Jordan., Interns O.

383

The intermediate principal stress effect on faulting and fault orientation  

NASA Astrophysics Data System (ADS)

We conducted true triaxial compression tests on rectangular prismatic specimens (19×19×38 mm) of siltstone core extracted from a depth of 1252 m, some 140 m below the borehole intersection with the Chelungpu Fault, Taiwan. Experiments consisted of four series of tests in each of which ?3 was kept constant and ?2 was varied from test to test. The major principal stress (?1), aligned with the long vertical side of the specimen, was raised at constant strain rate until a through-going, steeply dipping fault was initiated. As in igneous and metamorphic rocks previously tested, ?1 required to bring about faulting rose as ?2 was set at increasing levels above ?3. This observation reflects the significant contribution of ?2 to the compressive strength, and raises doubt about the suitability of the Mohr-Coulomb criterion. Rather, a strength criterion in terms of the invariants octahedral shear stress (?oct) as a function of mean stress (?oct) provides a good fit to the experimental data. In all tests fault strike was aligned with ?2 direction. The angle (or dip) ? of the fault was also strongly affected by ?2. For constant ?3 the angle rose with ?2, again departing from the Mohr-Coulomb criterion, which predicts a fault angle independent of the intermediate principal stress. The experimental results, revealing the dependence of fault angle ? on ?2, were compared with predictions based on shear localization theory incorporating a yield surface and plastic potential that depend on the following three stress invariants (rather than two, as in Rudnicki and Rice, 1975): ?oct, ?oct, and the Lode angle ?L (=arctan{[2?2 - ?1 - ?3]-[?3 (?1 - ?3)]}). Dependences of the yield surface and plastic potential on mean stress were inferred from the fault angles observed in axisymmetric compression and deviatoric pure shear. Using these relationships to predict fault angle ? for deviatoric stress states other than axisymmetric compression and pure shear, yields good agreement with the experimental observations. The results predict that for constant mean stress, the fault angle ? decreases as the deviatoric stress state varies from axisymmetric extension to axisymmetric compression. For fixed deviatoric stress states, ? decreases monotonically with increasing mean stress.

Haimson, Bezalel; Rudnicki, John

2010-05-01

384

Passive fault current limiting device  

DOEpatents

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

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

1999-04-06

385

Tremor, the curious third wheel of fault motion (Invited)  

NASA Astrophysics Data System (ADS)

The known universe of tectonic fault behavior has gained a new neighborhood in the last few years. Before, faults were considered to either conform to the reasonably well-understood earthquake cycle or else slide steadily. In the earthquake cycle, a fault stays locked for the years while stress is accumulating, then cracks and slides, releasing about 0.1-10 MPa of the stress on the fault. The crack spreads across the fault at roughly the shear wave velocity, kilometers per second. Sliding across the crack occurs at rates on the order of a meter per second. Deeper than the locked portion, faults were assumed to move stealthily and steadily. Disrupting this orderly bipartite universe has been tremor - a prolonged, noise-like, 1-10 Hz rumbling that has been spotted below the locked portion of a variety of faults. In subduction zones, often tremor is coincident with slow and low-stress-drop slip that takes many orders of magnitude longer to complete than garden-variety earthquakes, with the rupture progression estimated in km per day rather than per second. The so-called episodic tremor and slip (ETS) is seen to strike at much more regular intervals than old-fashioned quakes. Speculation and disjoint observations abound. Probably the observations represent just the most easily observed portions of a process that moves with power at all frequencies. The spectrum of tremor radiation is less “red” than that of earthquakes for periods shorter than their duration. Near-lithostatic pore pressure may play an important role in lubricating ETS activity. ETS activity appears generally restricted to only some major faults. Strong passing surface waves from distant great earthquakes trigger pulsations of tremor. Strong nearby earthquakes can cause weeks of stronger than normal tremor. The ebb and flow of diurnal tides cause a rise and fall in tremor amplitude. Tremor can contain earthquake-like short bursts of energy, even dozens of discrete pops, all with the less red spectra that marks tremor. The tremor moments in the Cascadia population follow the frequency scaling laid down by this lecture's namesake, the Gutenberg-Richter distribution, just like normal earthquakes. More practically, tremor is loading dangerous faults, such as near Seattle and Los Angeles, at unsteady rates, perhaps allowing estimations of variable levels of danger. Tremor probably silhouettes where the fault is locked, with alarming implications in some places. We can hope that tremor evolves through the earthquake cycle of the locked zone above in a way revealing the approach of feared events. It is a rare phenomenon that attracts so much inquiry, yet remains so obscure. No doubt, by AGU time, our seismic flashlights will have illuminated a few more juicy tidbits, and with luck bring us closer to the secret of tremor, which still lingers in an unlit corner.

Vidale, J. E.

2009-12-01

386

Geophysical methods applied to fault characterization and earthquake potential assessment in the Lower Tagus Valley, Portugal  

NASA Astrophysics Data System (ADS)

The study region is located in the Lower Tagus Valley, central Portugal, and includes a large portion of the densely populated area of Lisbon. It is characterized by a moderate seismicity with a diffuse pattern, with historical earthquakes causing many casualties, serious damage and economic losses. Occurrence of earthquakes in the area indicates the presence of seismogenic structures at depth that are deficiently known due to a thick Cenozoic sedimentary cover. The hidden character of many of the faults in the Lower Tagus Valley requires the use of indirect methodologies for their study. This paper focuses on the application of high-resolution seismic reflection method for the detection of near-surface faulting on two major tectonic structures that are hidden under the recent alluvial cover of the Tagus Valley, and that have been recognized on deep oil-industry seismic reflection profiles and/or inferred from the surface geology. These are a WNW ESE-trending fault zone located within the Lower Tagus Cenozoic basin, across the Tagus River estuary (Porto Alto fault), and a NNE SSW-trending reverse fault zone that borders the Cenozoic Basin at the W (Vila Franca de Xira Lisbon fault). Vertical electrical soundings were also acquired over the seismic profiles and the refraction interpretation of the reflection data was carried out. According to the interpretation of the collected data, a complex fault pattern disrupts the near surface (first 400 m) at Porto Alto, affecting the Upper Neogene and (at least for one fault) the Quaternary, with a normal offset component. The consistency with the previous oil-industry profiles interpretation supports the location and geometry of this fault zone. Concerning the second structure, two major faults were detected north of Vila Franca de Xira, supporting the extension of the Vila Franca de Xira Lisbon fault zone northwards. One of these faults presents a reverse geometry apparently displacing Holocene alluvium. Vertical offsets of the Holocene sediments detected in the studied geophysical data of Porto Alto and Vila Franca de Xira Lisbon faults imply minimum slip rates of 0.15 0.30 mm/year, three times larger than previously inferred for active faults in the Lower Tagus Valley and maximum estimates of average return periods of 2000 5000 years for M 6.5 7 co-seismic ruptures.

Carvalho, João; Cabral, João; Gonçalves, Rui; Torres, Luís; Mendes-Victor, Luís

2006-06-01

387

Intraplate Deformation of the Anatolian Micro Plate on the Amasya Branch Fault in Central Anatolia, Turkey  

NASA Astrophysics Data System (ADS)

The discrepancy between geologic and geodetic slip rate along the North Anatolian fault has been more evident as solid incremental (Kondo et al. 2010) and cumulative (Kozaci et al. 2009, Okumura et al. 2010) slip rate data are accumulated. The strain transient effect (Kozaci et al. 2009) could be a plausible cause for the discrepancy. At the same time, the seismicity, crustal deformation, and active structures indicate significant amount of distributed tectonic strain far inside the Anatolian micro plate. The accumulation and release of the distributed strain may affect the seismic cycle of the plate boundary. However, there is almost no quantitative information on the earthquakes and faults in central Anatolia. Considering the magnitude of the discrepancy, it is important to understand the intra-plate tectonics and to prepare for the seismic hazard in less active intra-plate areas. For this purpose, the author carried out detailed survey of the Amasya fault. Amasya fault is the only major branch of the North Anatolian fault in Central Anatolia. While the main strand of the North Anatolian fault steps at the Niksar basin, the Amasya fault is the westward continuation of the North Anatolian fault along the Kerkit river valley in the east. The fault extends to southwest over 250 km into the Anatolian micro plate. In 1939 about 100 km long eastern portion of the Amasya fault ruptured together with the 200 km long main strand between Niksar and Erzincan. The location and slip distribution of the 1939 ruptures, as well as slip-rate and paleoseismicity on the Amasya fault have been studied very little. Preliminary fault mapping between 36° E and 37° E was done with Google-Earth satellite photos and 1939 rupture locations were confirmed on site by interviews to aged local people. Cumulative slip measurement and slip-rate estimation were conducted in east of Canbolat (37.6228° E) and east of Findicak (36.4572° E). At Canbolat, 11.4 m cumulative offset was measured on faulted hill slope. Assuming the periglacial origin of the slope formation, preliminary slip-rate estimate is more than 1 mm/yr. At Findicak, offset terrace-riser indicate 7 to 8 m cumulative offset. The riser predates 2000--3000 year old terrace surface, and a rough estimate of the slip-rate is less than a few mm/yr. Further investigation on paleoseismicity is strongly required on the Amasya fault and other active structures.

Okumura, K.

2010-12-01

388

System fault protection design for the Cassini spacecraft  

Microsoft Academic Search

Fault protection can include a wide range of topics, ranging from fault prevention to autonomous fault detection and recovery. This paper will address a portion of the autonomous fault detection and recovery implemented on board the Cassini spacecraft. Specifically, the topic is system level fault protection design, as opposed to subsystem fault protection design. The design of system fault protection

J. P. Slonski

1996-01-01

389

Geologic and geochemical study of the Picacho gold mine, California: gold in a low-angle normal fault environment  

NASA Astrophysics Data System (ADS)

The Picacho gold deposit, located in southeasternmost California, is a low-grade gold deposit in a nearly flat-lying denudational fault of regional extent and probable Oligocene age. The deposit is hosted by intensely fractured and faulted Mesozoic leucogranite and by chloritic augen gneiss and schist, and is overlain unconformably and in fault contact by unmineralized late Oligocene Quechan volcanic rocks. The deposit is structurally characterized by normal and normal-oblique faults of low to high dip at shallow depths in the mine, merging downward with a synchronous, low-dipping ore-stage extensional fault system (the Chocolate Mountains/Gatuna Fault) of probable Oligocene age in deeper portions of the deposit. The fault system was infiltrated during much of its active life by hot, dilute, highly exchanged meteoric water having temperatures of 170°-210° C, salinity <2 wt% NaCl equivalent and calculated ?18Ofluid between -2.6‰ and 5.2‰. This main-stage fluid precipitated quartz, pyrite, and specular hematite, accompanied by silicification and sericitization. Auriferous ore-stage pyrite was precipitated late in the fault evolution probably by mixing of reducing ore fluid with relatively oxidized main-stage fluid during regional Oligocene extension on the Chocolate Mountains/Gatuna Fault. The Picacho deposit is characterized by a gold-arsenic-antimony geochemical signature consistent with bisulfide complexing of gold in reducing fluid, in contrast with typical denudation fault-hosted base-metal-rich deposits associated with high-salinity fluids elsewhere in the southwestern United States. The deposit is overprinted by Miocene normal faults having a wide range of dips. These postore faults are associated with red earthy hematite precipitation, pyrite oxidation, and supergene enrichment of gold.

Losh, Steven; Purvance, Dan; Sherlock, Ross; Jowett, E. Craig

2005-03-01

390

Fault Analysis in Solar Photovoltaic Arrays  

NASA Astrophysics Data System (ADS)

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

Zhao, Ye

391

South Fork Clearwater River Habitat Enhancement, Nez Perce National Forest.  

SciTech Connect

In 1984, the Nez Perce National forest and the Bonneville Power Administration entered into a contractual agreement which provided for improvement of spring chinook salmon and summer steelhead trout habitat in south Fork Clearwater River tributaries. Project work was completed in seven main locations: Crooked River, Red River, Meadow Creek Haysfork Gloryhole, Cal-Idaho Gloryhole, Fisher Placer and Leggett Placer. This report describes restoration activities at each of these sites.

Siddall, Phoebe

1992-04-01

392

Modeling of externally-induced\\/common-cause faults in fault-tolerant systems  

Microsoft Academic Search

Modeling fault behaviors such as fault occurrences and active\\/benign durations is an essential step to the design and evaluation of fault-tolerant controller computers. We use a beta-binomial distribution to model fault occurrences both in the presence and in the absence of environmentally-induced (thus common-cause) faults. A multinomial distribution is used to model fault active durations. The proposed model is validated

Hagbae Kim; Kang G. Shin

1994-01-01

393

Numerical simulation of formation process of fault zone structures considering various mechanical fault properties  

NASA Astrophysics Data System (ADS)

Fault core samples retrieved by deep drilling allow us to directly obtain information of fault zone architectures and mechanical properties of fault rocks. It is qualitatively known that the form of fault zone structures are affected by the mechanical rock properties. Therefore understanding the formation process of fault zone structure will help to understand the mechanical property of fault zones, enhancing the better use of fault core samples. Well know process linking the material property and the structure is strength evolution due to successive straining: strain softening properties lead the formation of localized strain bands and, by contrast, strain hardening results in pervasive structures. However, there is another process contributing the formation of fault zone structures that is the failure of off-fault medium due to stress concentration at rupture tips. It is poorly understood how these processes affect under the actual condition natural faults obeying. By numerically modeling the off-fault failures associated with dynamic rupture propagation, we quantitatively investigate the role of the material properties for the resulting fault zone structures. In elastic full space, we assume a main fault with a large number of secondary faults spontaneously generated following a slip-weakening based fracture criterion. We simulate how secondary faults are generated and make a fault zone. We had found that the width of a fault zone created by this mechanism is a linearly increasing function of the main fault length until the main fault length exceeds a certain critical length Lm. With a set of parameter study, it is found that the fault zone width is a decreasing function of yield strength of medium surrounding the fault. The characteristic slip weakening distance Dc does not affect to the width significantly but it affects to the amount and distribution of slip on the secondary faults. These relations may help to estimate fault properties based on the analysis of internal fault zone structures.

Ando, R.

2010-12-01

394

Dynamic Processes of Fault Creep along the Chihshang Fault, Taiwan  

NASA Astrophysics Data System (ADS)

Active fault creep along the Chihshang fault in Taiwan has been observed for the past 20 years (Lee et al., 2004). The Chihshang Creepmeter experiment was set up across this most active segment along the Longitudinal Valley fault system, the present-day plate suture between the Eurasian and the Philippine Sea plates in eastern Taiwan. The daily creep data revealed an annual shortening rate ranging from 13 to 18 mm across the fault. The data exhibit a distinct seasonal variation, with the fault creeping steadily in the rainy season and remaining locked during the dry season of the year. Similar observations were also observed in other places of the world, for example, the Parkfield section of the San Andreas Fault. Based on the water level observation in a nearby monitoring well, we calculated the Coulomb failure stress changes induced by the underground water level change. Contributions to the Coulomb failure stress changes are from: (1) the pore water pressure change as a result of the change in ground water table (0.3 bars); (2) loading on the footwall induced by the difference in porosities between the footwall and hanging wall materials (0.1 bars). We found that the loading in the shallow surface layer due to recharge of its aquifer system in the wet-season has increased the Coulomb failure stress and results in periodic creeping activity along the Chihshang fault. For a rate and state dependent friction process, we found the parameter (A-B) is around 10e-3. We constrained the friction parameter (A-B) using observations of the postseismic creep triggered by the Coulomb stress changes of the M6.5 Chengkung, Taiwan earthquake that occurred on the same fault segment in 2003. We re-examined the Coulomb failure stress change for the seasonal induced creep process and found the value is between that with and without the maximum effect of pore water pressure, suggesting a partial hydraulic interconnection of the fault system to its surrounding structures.

Zeng, Y.; Shen, Z.; Lee, J.

2005-12-01

395

River Walk.  

ERIC Educational Resources Information Center

Describes a teaching approach that prompts students to help community, state, and federal agencies make decisions on the best uses of rivers and their surroundings. Includes tracking water quality and designing signs to educate the community. (YDS)

Schmaus, Marcyes D.

2001-01-01

396

River Blindness  

MedlinePLUS

... volunteers who are exposed to blackfly bites in endemic areas. The disease is most prevalent in remote ... 15 years. If you have been in an endemic area and think you might have contracted river ...

397

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

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

398

Connecting the Yakima fold and thrust belt to active faults in the Puget Lowland, Washington  

NASA Astrophysics Data System (ADS)

High-resolution aeromagnetic surveys of the Cascade Range and Yakima fold and thrust belt (YFTB), Washington, provide insights on tectonic connections between forearc and back-arc regions of the Cascadia convergent margin. Magnetic surveys were measured at a nominal altitude of 250 m above terrain and along flight lines spaced 400 m apart. Upper crustal rocks in this region have diverse magnetic properties, ranging from highly magnetic rocks of the Miocene Columbia River Basalt Group to weakly magnetic sedimentary rocks of various ages. These distinctive magnetic properties permit mapping of important faults and folds from exposures to covered areas. Magnetic lineaments correspond with mapped Quaternary faults and with scarps identified in lidar (light detection and ranging) topographic data and aerial photography. A two-dimensional model of the northwest striking Umtanum Ridge fault zone, based on magnetic and gravity data and constrained by geologic mapping and three deep wells, suggests that thrust faults extend through the Tertiary section and into underlying pre-Tertiary basement. Excavation of two trenches across a prominent scarp at the base of Umtanum Ridge uncovered evidence for bending moment faulting possibly caused by a blind thrust. Using aeromagnetic, gravity, and paleoseismic evidence, we postulate possible tectonic connections between the YFTB in eastern Washington and active faults of the Puget Lowland. We suggest that faults and folds of Umtanum Ridge extend northwestward through the Cascade Range and merge with the Southern Whidbey Island and Seattle faults near Snoqualmie Pass 35 km east of Seattle. Recent earthquakes (MW ? 5.3) suggest that this confluence of faults may be seismically active today.

Blakely, Richard J.; Sherrod, Brian L.; Weaver, Craig S.; Wells, Ray E.; Rohay, Alan C.; Barnett, Elizabeth A.; Knepprath, Nichole E.

2011-07-01

399

Fault-tolerant architecture: Evaluation methodology  

SciTech Connect

The design and reliability of four fault-tolerant architectures that may be used in nuclear power plant control systems were evaluated. Two architectures are variations of triple-modular-redundant (TMR) systems, and two are variations of dual redundant systems. The evaluation includes a review of methods of implementing fault-tolerant control, the importance of automatic recovery from failures, methods of self-testing diagnostics, block diagrams of typical fault-tolerant controllers, review of fault-tolerant controllers operating in nuclear power plants, and fault tree reliability analyses of fault-tolerant systems.

Battle, R.E; Kisner, R.A. (Oak Ridge National Lab., TN (United States))

1992-08-01

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PC-based fault finder  

SciTech Connect

Electric utilities are continually pressed to stay competitive while meeting the increasing demand of today's sophisticated customer. Advances in electron equipment and the improved array of electric driven devices are setting new standards for improved reliability and quality of service. Besides the specifications on voltage and frequency regulation and the permitted harmonic content, to name a few, the number and duration of service interruptions have a dramatic direct effect on the customer. Accurate fault locating reduces transmission line patrolling and is of particular significance in repairing long lines in rough terrain. Shortened outage times, reduced equipment degrading and stress on the system, fast restored service, and improved revenue are immediate outcomes of fast fault locating which insure minimum loss of system security. This article focuses on a PC-based (DOS) computer program that has unique features for identifying the type of fault and its location on overhead transmission/distribution lines. Balanced and unbalanced faults are identified and located accurately while accounting for changes in conductor sizes and network configuration. The presented concepts and methodologies have been spurred by Otter Tail Power's need for an accurate fault locating scheme to accommodate multiple feeders with mixed lone configurations. A case study based on a section of the Otter Tail network is presented to illustrate the features and capabilities of the developed software.

Bengiamin, N.N. (Univ. of North Dakota, Grand Forks, ND (United States)); Jensen, C.A. (Univ. of North Dakota, Grand Forks, ND (United States). Electrical Engineering Dept. Otter Tail Power Co., Fergus Falls, MN (United States). System Protection Group); McMahon, H. (Otter Tail Power, Fergus Falls, MN (United States))

1993-07-01