Science.gov

Sample records for aegir ridge prior

  1. Prior Tectonic Brecciation Favors Carbonation of Abyssal Serpentinites : a Petrographic and Stable Isotope Study of Southwest Indian Ridge Dredged Samples.

    NASA Astrophysics Data System (ADS)

    Cannat, M.; Payré, V.; Martinez, I.

    2014-12-01

    Partial carbonation of the uppermost oceanic lithosphere represents a significant natural reservoir for long term carbon storage. About 25% of the oceanic basement formed at slow spreading ridges is made of tectonically exhumed and variably serpentinized abyssal peridotites in which carbonates veins have been documented. Previous studies indicate formation of these veins at temperatures between ~180°C and <10°C, at the seafloor or in shallow levels of the exhumation faults, and from fluids ranging from pure seawater to seawater-hydrothermal fluids mixtures. In this presentation we show that partial carbonation of serpentinites dredged at and near the easternmost Southwest Indian Ridge (SWIR) similarly occurred in two settings: dolomite formed at temperatures ~50°C presumably in shallow fluid-rich domains of the exhumation fault(s), while aragonite formed at yet lower temperatures within a few meters of the seafloor. We also present a detailed petrographic study of carbonation textures showing that while carbonate veining is prevalent in the seafloor-type carbonation, it is superseeded by serpentine dissolution and replacement in our samples of the fault zone-type carbonation. In these samples, dolomite preferably replaces the matrix of a tectonic breccia, that comprises angular clasts of serpentinite. TEM observations and diffraction patterns identify this matrix as microcrystalline to amorphous serpentine and document the contacts between this material and the dolomite. A comparison with textures reported for carbonated serpentine breccia from the Alps, and the Galicia margin suggests that prior tectonic brecciation enhances the potential for pervasive carbonation of serpentinites in the oceanic lithosphere at both mid-ocean ridges and the ocean-continent transition of divergent continental margins.

  2. Seismic reflection imaging of the Juan de Fuca plate from ridge to trench: New constraints on the distribution of faulting and evolution of the crust prior to subduction

    NASA Astrophysics Data System (ADS)

    Han, Shuoshuo; Carbotte, Suzanne M.; Canales, Juan Pablo; Nedimović, Mladen R.; Carton, Hélène; Gibson, James C.; Horning, Greg W.

    2016-03-01

    We present prestack time-migrated multichannel seismic images along two cross-plate transects from the Juan de Fuca (JdF) Ridge to the Cascadia deformation front (DF) offshore Oregon and Washington from which we characterize crustal structure, distribution and extent of faults across the plate interior as the crust ages and near the DF in response to subduction bending. Within the plate interior, we observe numerous small offset faults in the sediment section beginning 50-70 km from the ridge axis with sparse fault plane reflections confined to the upper crust. Plate bending due to sediment loading and subduction initiates at ~120-150 km and ~65-80 km seaward of the DF, respectively, and is accompanied by increase in sediment fault offsets and enhancement of deeper fault plane reflectivity. Most bend faulting deformation occurs within 40 km from the DF; on the Oregon transect, bright fault plane reflections that extend through the crust and 6-7 km into the mantle are observed. If attributed to serpentinization, ~0.12-0.92 wt % water within the uppermost 6 km of the mantle is estimated. On the Washington transect, bending faults are confined to the sediment section and upper-middle crust. The regional difference in subduction bend-faulting and potential hydration of the JdF plate is inconsistent with the spatial distribution of intermediate-depth intraslab seismicity at Cascadia. A series of distinctive, ridgeward dipping (20°-40°) lower crustal reflections are imaged in ~6-8 Ma crust along both transects and are interpreted as ductile shear zones formed within the ridge's accretionary zone in response to temporal variations in mantle upwelling, possibly associated with previously recognized plate reorganizations at 8.5 Ma and 5.9 Ma.

  3. Hydrology Prior to Wetland and Prairie Restoration in and around the Glacial Ridge National Wildlife Refuge, Northwestern Minnesota, 2002-5

    USGS Publications Warehouse

    Cowdery, Timothy K.; Lorenz, David L.; Arntson, Allan D.

    2008-01-01

    The Nature Conservancy (TNC) owned and managed 24,795 acres of mixed wetland, native prairie, farmland and woods east of Crookston, in northwestern Minnesota. The original wetlands and prairies that once occupied this land are being restored by TNC in cooperation with many partners and are becoming part of the Glacial Ridge National Wildlife Refuge. Results of this study indicate that these restorations are likely to have a substantial effect on the local hydrology. Water occurs within the study area on the land surface, in surficial aquifers, and in buried aquifers of various depths, the tops of which are 50 to several hundred feet below the land surface. Surficial aquifers are generally thin (about 20 feet), narrow (several hundred feet), and long (tens of miles). Estimates of the horizontal hydraulic conductivity of surficial aquifers were 2.7?300 feet per day. Buried aquifers underlie much of the study area, but interact with surficial aquifers only in isolated areas. In these areas, water flows directly from buried to surficial aquifers and forms a single aquifer as much as 78 feet thick. The surface?water channel network is modified by several manmade ditches that were installed to remove excess water seasonally and to drain wetlands. The channels of the network lie primarily parallel to the beach ridges but cut through them in places. Back?beach basin wetlands delay and reduce direct runoff to ditches. Recharge to the surficial aquifers (10.97?25.08 inches per year during 2003?5) is from vertical infiltration of rainfall and snowmelt (areal recharge); from surface waters (particularly ephemeral wetlands); and from upward leakage of water from buried aquifers through till confining units (estimated at about 1 inch per year). Areal recharge is highly variable in space and time. Water leaves (discharges from) the surficial aquifers as flow to surface waters (closed basins and ditches), evapotranspiration, and withdrawals from wells. Unmeasured losses (primarily

  4. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion.

    PubMed

    Roehrig, John T; Butrapet, Siritorn; Liss, Nathan M; Bennett, Susan L; Luy, Betty E; Childers, Thomas; Boroughs, Karen L; Stovall, Janae L; Calvert, Amanda E; Blair, Carol D; Huang, Claire Y-H

    2013-07-05

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion.

  5. Mutation of the dengue virus type 2 envelope protein heparan sulfate binding sites or the domain III lateral ridge blocks replication in Vero cells prior to membrane fusion

    SciTech Connect

    Roehrig, John T.; Butrapet, Siritorn; Liss, Nathan M.; Bennett, Susan L.; Luy, Betty E.; Childers, Thomas; Boroughs, Karen L.; Stovall, Janae L.; Calvert, Amanda E.; Blair, Carol D.; Huang, Claire Y.-H.

    2013-07-05

    Using an infectious cDNA clone we engineered seven mutations in the putative heparan sulfate- and receptor-binding motifs of the envelope protein of dengue virus serotype 2, strain 16681. Four mutant viruses, KK122/123EE, E202K, G304K, and KKK305/307/310EEE, were recovered following transfection of C6/36 cells. A fifth mutant, KK291/295EE, was recovered from C6/36 cells with a compensatory E295V mutation. All mutants grew in and mediated fusion of virus-infected C6/36 cells, but three of the mutants, KK122/123EE, E202K, G304K, did not grow in Vero cells without further modification. Two Vero cell lethal mutants, KK291/295EV and KKK307/307/310EEE, failed to replicate in DC-SIGN-transformed Raji cells and did not react with monoclonal antibodies known to block DENV attachment to Vero cells. Additionally, both mutants were unable to initiate negative-strand vRNA synthesis in Vero cells by 72 h post-infection, suggesting that the replication block occurred prior to virus-mediated membrane fusion. - Highlights: • Heparan sulfate- and receptor-binding motifs of DENV2 envelope protein were mutated. • Four mutant viruses were isolated—all could fuse C6/36 cells. • Two of these mutants were lethal in Vero cells without further modification. • Lethal mutations were KK291/295EV and KKK305/307/310EEE. • Cell attachment was implicated as the replication block for both mutants.

  6. Geophysical survey of the Eggvin Bank and Logi Ridge - Greenland Sea

    NASA Astrophysics Data System (ADS)

    Breivik, A. J.; Mjelde, R.; Rai, A. K.; Frassetto, A.

    2012-12-01

    The northern Greenland Sea has a number of features associated with excess volcanism. These include the Jan Mayen island, the Jan Mayen Plateau north of, and the Eggvin Bank west of Jan Mayen, and the Vesteris Seamount far to the north. In the summer of 2011, we colleced an Ocean Bottom Seismometer (OBS) profile across the Eggvin Bank, returning four good data sets. We also collected single-channel reflection seismic (SCS) data along the OBS line. The profile crosses the transform part of the West Jan Mayen Fracture Zone (WJMFZ), which connects seafloor spreading between the Kolbeinsey and Mohn ridges. Between the WJMFZ and the Vesteris Seamount there is a narrow ridge 170-180 km long, ending in a few seamounts in the east. It disturbs the magnetic seafloor anomalies, and has no conjugate on the Norwegian margin. It thus appears to be younger than the Eocene seafloor it lies on. Trend and position points to Traill Ø in East Greenland, which had magmatism at ~36 Ma. We name it the Logi Ridge after Norse mythology, where Logi is the master of fire, brother of Aegir, master of the sea. We have collected five SCS profiles across this ridge in order to study the surrounding sedimentation pattern. We also collected gravity and magnetic data along all profiles. Initial results show two flat-topped seamounts on the Eggvin Bank, and a flat-topped Logi Ridge, indicating that these have been at sealevel. The sedimentary strata show recent vertical movement north of the WJMFZ near the Jan Mayen Plateau, and compression around the Logi Ridge. Sailing line of R/V Håkon Mosby of Bergen. Survey lines are in bold, and OBS positions are marked by circles.

  7. Homogeneous geochemical signal of Jan Mayen intraplate volcanism and its radial dispersion along adjacent ultra-slow spreading ridges.

    NASA Astrophysics Data System (ADS)

    Hamelin, C.; Pedersen, R. B.

    2014-12-01

    The volcanically active Jan Mayen Island is found on the northern tip of the Jan Mayen microcontinent, a continental fragment rifted from the Greenland coast 25 My ago following the ridge jump from Aegir to Kolbeinsey Ridge. The recurrent debate about the origin of Jan Mayen is partly due to the complex geological setting of the island. It is located directly south of the Jan Mayen Fracture Zone (JMFZ) and between the ultraslow Mohns and Kolbeinsey spreading ridges. Over the years, this intraplate volcanic suite has been diversely interpreted as an isolated hotspot, as Icelandic plume material dispersed in the northern Atlantic, as the result of melting of a sub-continental lithospheric mantle, or as a result from the coincidence of a continental fragment in the prolongation of a spreading center. However, recent U-series data (Elkins et al., 2011; 2014; in prep.) as well as geophysical high-resolution S-velocity model (Rickers et al., 2013) both indicate a high-temperature anomaly in this area, supporting the hotspot hypothesis. We present new major, trace elements, Sr, Nd, Pb and Hf isotope data for samples collected near Jan Mayen and along Kolbeinsey and Mohns Ridges, together with a new bathymetry map. One of the most striking results from Jan Mayen area is the relative homogeneity in the geochemical signature around the island compared to other hotspots. These limited geochemical variations are surprising considering that these lavas are erupted on top of a fragment of continental crust in a ridge-hotspot-fracture zone context. Along Kolbeinsey and Mohns Ridges, we observed a radial dispersion and mixing of Jan Mayen signature within the local depleted upper mantle. The difference in the geochemical gradients on both sides of the JMFZ could be linked to the difference in ridge morphology between Kolbeinsey (orthogonal, symmetric spreading, shallow and high magma supply) and Mohns Ridges (oblique, asymmetric spreading, deeper and weaker magma supply).

  8. Metopic ridge

    MedlinePlus

    ... plates allow for growth of the skull. The places where these plates connect are called sutures or suture lines. They do not fully close until the 2nd or 3rd year of life. A metopic ridge occurs when ...

  9. Ridge 2000 Data Management System

    NASA Astrophysics Data System (ADS)

    Goodwillie, A. M.; Carbotte, S. M.; Arko, R. A.; Haxby, W. F.; Ryan, W. B.; Chayes, D. N.; Lehnert, K. A.; Shank, T. M.

    2005-12-01

    Hosted at Lamont by the marine geoscience Data Management group, mgDMS, the NSF-funded Ridge 2000 electronic database, http://www.marine-geo.org/ridge2000/, is a key component of the Ridge 2000 multi-disciplinary program. The database covers each of the three Ridge 2000 Integrated Study Sites: Endeavour Segment, Lau Basin, and 8-11N Segment. It promotes the sharing of information to the broader community, facilitates integration of the suite of information collected at each study site, and enables comparisons between sites. The Ridge 2000 data system provides easy web access to a relational database that is built around a catalogue of cruise metadata. Any web browser can be used to perform a versatile text-based search which returns basic cruise and submersible dive information, sample and data inventories, navigation, and other relevant metadata such as shipboard personnel and links to NSF program awards. In addition, non-proprietary data files, images, and derived products which are hosted locally or in national repositories, as well as science and technical reports, can be freely downloaded. On the Ridge 2000 database page, our Data Link allows users to search the database using a broad range of parameters including data type, cruise ID, chief scientist, geographical location. The first Ridge 2000 field programs sailed in 2004 and, in addition to numerous data sets collected prior to the Ridge 2000 program, the database currently contains information on fifteen Ridge 2000-funded cruises and almost sixty Alvin dives. Track lines can be viewed using a recently- implemented Web Map Service button labelled Map View. The Ridge 2000 database is fully integrated with databases hosted by the mgDMS group for MARGINS and the Antarctic multibeam and seismic reflection data initiatives. Links are provided to partner databases including PetDB, SIOExplorer, and the ODP Janus system. Improved inter-operability with existing and new partner repositories continues to be

  10. Ridge suction drives plume-ridge interactions

    NASA Astrophysics Data System (ADS)

    Niu, Y.; Hékinian, R.

    2003-04-01

    Deep-sourced mantle plumes, if existing, are genetically independent of plate tectonics. When the ascending plumes approach lithospheric plates, interactions between the two occur. Such interactions are most prominent near ocean ridges where the lithosphere is thin and the effect of plumes is best revealed. While ocean ridges are mostly passive features in terms of plate tectonics, they play an active role in the context of plume-ridge interactions. This active role is a ridge suction force that drives asthenospheric mantle flow towards ridges because of material needs to form the ocean crust at ridges and lithospheric mantle in the vicinity of ridges. This ridge suction force increases with increasing plate separation rate because of increased material demand per unit time. As the seismic low-velocity zone atop the asthenosphere has the lowest viscosity that increases rapidly with depth, the ridge-ward asthenospheric flow is largely horizontal beneath the lithosphere. Recognizing that plume materials have two components with easily-melted dikes/veins enriched in volatiles and incompatible elements dispersed in the more refractory and depleted peridotitic matrix, geochemistry of some seafloor volcanics well illustrates that plume-ridge interactions are consequences of ridge-suction-driven flow of plume materials, which melt by decompression because of lithospheric thinning towards ridges. There are excellent examples: 1. The decreasing La/Sm and increasing MgO and CaO/Al_2O_3 in Easter Seamount lavas from Salas-y-Gomez Islands to the Easter Microplate East rift zone result from progressive decompression melting of ridge-ward flowing plume materials. 2. The similar geochemical observations in lavas along the Foundation hotline towards the Pacific-Antarctic Ridge result from the same process. 3. The increasing ridge suction force with increasing spreading rate explains why the Iceland plume has asymmetric effects on its neighboring ridges: both topographic and

  11. Ridge Regression: A Panacea?

    ERIC Educational Resources Information Center

    Walton, Joseph M.; And Others

    1978-01-01

    Ridge regression is an approach to the problem of large standard errors of regression estimates of intercorrelated regressors. The effect of ridge regression on the estimated squared multiple correlation coefficient is discussed and illustrated. (JKS)

  12. Grafts for Ridge Preservation

    PubMed Central

    Jamjoom, Amal; Cohen, Robert E.

    2015-01-01

    Alveolar ridge bone resorption is a biologic phenomenon that occurs following tooth extraction and cannot be prevented. This paper reviews the vertical and horizontal ridge dimensional changes that are associated with tooth extraction. It also provides an overview of the advantages of ridge preservation as well as grafting materials. A Medline search among English language papers was performed in March 2015 using alveolar ridge preservation, ridge augmentation, and various graft types as search terms. Additional papers were considered following the preliminary review of the initial search that were relevant to alveolar ridge preservation. The literature suggests that ridge preservation methods and augmentation techniques are available to minimize and restore available bone. Numerous grafting materials, such as autografts, allografts, xenografts, and alloplasts, currently are used for ridge preservation. Other materials, such as growth factors, also can be used to enhance biologic outcome. PMID:26262646

  13. Calculating a Stepwise Ridge Regression.

    ERIC Educational Resources Information Center

    Morris, John D.

    1986-01-01

    Although methods for using ordinary least squares regression computer programs to calculate a ridge regression are available, the calculation of a stepwise ridge regression requires a special purpose algorithm and computer program. The correct stepwise ridge regression procedure is given, and a parallel FORTRAN computer program is described.…

  14. Louisiana slope salt-ridge continuity confirmed

    SciTech Connect

    Lowrie, A.; Hoffman, K.S.; Sullivan, N.

    1989-03-01

    The Louisiana offshore is a world-class hydrocarbon province. Abundant reservoirs develop as the result of interaction between salt tectonics and sedimentation. Thus, it is essential to know both regional and local characteristics of the extent and timing of salt tectonics as an aid in hydrocarbon exploration. Exploration mythology mandates that salt domes and ridges are virtually random across the slope area. In sharp contrast, the authors describe a definite pattern to the salt ridges of slightly concave (to the north) arcs, with the southernmost arc located along the Sigsbee Escarpment and the northernmost along the shelf break. Furthermore, salt domes may not be truly randomly located but rather part of ancestral or existent salt ridges. Confirming data are provided by dip bathymatric and seismic profiles. The bathymetric profiles are at 5-mi (8-km) spacings from 1987 published charts of the Gulf of Mexico. Dip seismic lines reveal that bathymetric highs are associated with underlying salt. Buried salt accumulations are surficially expressed by actual ridges and domes, a leveling of sea floor, or a local decrease in the rate of regional slope descent. Salt is the Neogene-age basement of the Louisiana slope. The existence of an overall salt-ridge pattern implies that there is a single dynamic geologic system controlling the evolution of this slope. As salt tectonic rates and timing are deciphered for specific sites along dip, intervening rates may be interpolated to unmapped zones. Confirming an overall salt tectonic pattern is mandatory prior to quantifying regional and specific rates for the whole slope.

  15. Ridge regression processing

    NASA Technical Reports Server (NTRS)

    Kuhl, Mark R.

    1990-01-01

    Current navigation requirements depend on a geometric dilution of precision (GDOP) criterion. As long as the GDOP stays below a specific value, navigation requirements are met. The GDOP will exceed the specified value when the measurement geometry becomes too collinear. A new signal processing technique, called Ridge Regression Processing, can reduce the effects of nearly collinear measurement geometry; thereby reducing the inflation of the measurement errors. It is shown that the Ridge signal processor gives a consistently better mean squared error (MSE) in position than the Ordinary Least Mean Squares (OLS) estimator. The applicability of this technique is currently being investigated to improve the following areas: receiver autonomous integrity monitoring (RAIM), coverage requirements, availability requirements, and precision approaches.

  16. Prior Knowledge Assessment Guide

    DTIC Science & Technology

    2014-12-01

    Research Product 2015-01 Prior Knowledge Assessment Guide Gary M. Stallings Northrop Grumman Corporation Jean L...Prior Knowledge Assessment Guide 5a. CONTRACT OR GRANT NUMBER W5J9CQ-11-D-0001 5b. PROGRAM ELEMENT NUMBER 633007 6. AUTHOR(S...instructors had a good understanding of what prior knowledge was relevant for their courses. The purpose of the guide documented in this report is

  17. Constrained noninformative priors

    SciTech Connect

    Atwood, C.L.

    1994-10-01

    The Jeffreys noninformative prior distribution for a single unknown parameter is the distribution corresponding to a uniform distribution in the transformed model where the unknown parameter is approximately a location parameter. To obtain a prior distribution with a specified mean but with diffusion reflecting great uncertainty, a natural generalization of the noninformative prior is the distribution corresponding to the constrained maximum entropy distribution in the transformed model. Examples are given.

  18. Jurassic zircons from the Southwest Indian Ridge.

    PubMed

    Cheng, Hao; Zhou, Huaiyang; Yang, Qunhui; Zhang, Lingmin; Ji, Fuwu; Dick, Henry

    2016-05-17

    The existence of ancient rocks in present mid-ocean ridges have long been observed but received less attention. Here we report the discovery of zircons with both reasonably young ages of about 5 Ma and abnormally old ages of approximate 180 Ma from two evolved gabbroic rocks that were dredged from the Southwest Indian Ridge (SWIR) in the Gallieni fracture zone. U-Pb and Lu-Hf isotope analyses of zircons were made using ion probe and conventional laser abrasion directly in petrographic thin sections. Young zircons and their host oxide gabbro have positive Hf isotope compositions (εHf = +15.7-+12.4), suggesting a highly depleted mantle beneath the SWIR. The spread εHf values (from-2.3 to-4.5) of abnormally old zircons, together with the unradiogenic Nd-Hf isotope of the host quartz diorite, appears to suggest an ancient juvenile magmatism along the rifting margin of the southern Gondwana prior to the opening of the Indian Ocean. A convincing explanation for the origin of the unusually old zircons is yet to surface, however, an update of the theory of plate tectonics would be expected with continuing discovery of ancient rocks in the mid-oceanic ridges and abyssal ocean basins.

  19. Jurassic zircons from the Southwest Indian Ridge

    NASA Astrophysics Data System (ADS)

    Cheng, Hao; Zhou, Huaiyang; Yang, Qunhui; Zhang, Lingmin; Ji, Fuwu; Dick, Henry

    2016-05-01

    The existence of ancient rocks in present mid-ocean ridges have long been observed but received less attention. Here we report the discovery of zircons with both reasonably young ages of about 5 Ma and abnormally old ages of approximate 180 Ma from two evolved gabbroic rocks that were dredged from the Southwest Indian Ridge (SWIR) in the Gallieni fracture zone. U–Pb and Lu–Hf isotope analyses of zircons were made using ion probe and conventional laser abrasion directly in petrographic thin sections. Young zircons and their host oxide gabbro have positive Hf isotope compositions (εHf = +15.7–+12.4), suggesting a highly depleted mantle beneath the SWIR. The spread εHf values (from‑2.3 to‑4.5) of abnormally old zircons, together with the unradiogenic Nd-Hf isotope of the host quartz diorite, appears to suggest an ancient juvenile magmatism along the rifting margin of the southern Gondwana prior to the opening of the Indian Ocean. A convincing explanation for the origin of the unusually old zircons is yet to surface, however, an update of the theory of plate tectonics would be expected with continuing discovery of ancient rocks in the mid-oceanic ridges and abyssal ocean basins.

  20. Jurassic zircons from the Southwest Indian Ridge

    PubMed Central

    Cheng, Hao; Zhou, Huaiyang; Yang, Qunhui; Zhang, Lingmin; Ji, Fuwu; Dick, Henry

    2016-01-01

    The existence of ancient rocks in present mid-ocean ridges have long been observed but received less attention. Here we report the discovery of zircons with both reasonably young ages of about 5 Ma and abnormally old ages of approximate 180 Ma from two evolved gabbroic rocks that were dredged from the Southwest Indian Ridge (SWIR) in the Gallieni fracture zone. U–Pb and Lu–Hf isotope analyses of zircons were made using ion probe and conventional laser abrasion directly in petrographic thin sections. Young zircons and their host oxide gabbro have positive Hf isotope compositions (εHf = +15.7–+12.4), suggesting a highly depleted mantle beneath the SWIR. The spread εHf values (from−2.3 to−4.5) of abnormally old zircons, together with the unradiogenic Nd-Hf isotope of the host quartz diorite, appears to suggest an ancient juvenile magmatism along the rifting margin of the southern Gondwana prior to the opening of the Indian Ocean. A convincing explanation for the origin of the unusually old zircons is yet to surface, however, an update of the theory of plate tectonics would be expected with continuing discovery of ancient rocks in the mid-oceanic ridges and abyssal ocean basins. PMID:27185575

  1. Interest and Prior Knowledge.

    ERIC Educational Resources Information Center

    Tobias, Sigmund

    This paper selectively reviews research on the relationship between topic interest and prior knowledge, and discusses the optimal association between these variables. The paper points out that interest has a facilitating impact on learning, and at least part of this effect must be ascribed to prior knowledge. While the interest-knowledge…

  2. Radioisotope production and management at Oak Ridge National Laboratory

    SciTech Connect

    Collins, E.D.; Aaron, W.S.; Alexander, C.W.; Bigelow, J.E.; Parks, J.T.; Tracy, J.G.; Wham, R.M.

    1994-09-01

    The production of radioisotopes has been one of the basic activities at Oak Ridge since the end of World War II. The importance of this work was best described by Alvin Weinberg, former Laboratory Director, when he wrote ``... If God has a golden book and writes down what it is that Oak Ridge National Laboratory did that had the biggest influence on science, I would guess that was the production and distribution of isotopes.`` Radioisotopes production continues to be an important aspect of Oak Ridge programs today and of those planned for the future. Past activities, current projects, and future plans and potentials will be described briefly in this paper. Also, some of the major issues facing the continued production of radioisotopes will be described. The scope of the program has always been primarily that of process development, followed by special batch-type productions, where no other supply exists. The technology developed has been available for adoption by US commercial corporations, and in cases where this has occurred, Oak Ridge has withdrawn as a supplier of the particular isotopes involved. One method of production that will not be described is that of target bombardment with an accelerator. This method was used at Oak Ridge prior to 1978 in the 86-inch Cyclotron. However, this method has not been used at Oak Ridge since then for radioisotope production, except as a research tool.

  3. Environmental baseline survey report for West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge and parcel 21D in the vicinity of the East Technology Park, Oak Ridge, Tennessee

    SciTech Connect

    King, David A.

    2012-11-29

    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy?s (DOE?s) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only no-further-investigation (NFI) reports. Groundwater sampling was also conducted to support a Parcel 21d decision. Based on available data West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, and West Pine Ridge are not impacted by site operations and are not subject to actions per the Federal Facility Agreement (FFA). This determination is supported by visual inspections, records searches and interviews, groundwater conceptual modeling, approved NFI reports, analytical data, and risk analysis results. Parcel 21d data, however, demonstrate impacts from site

  4. The structure of the Lomonosov Ridge, Arctic Ocean (Invited)

    NASA Astrophysics Data System (ADS)

    Jackson, H. R.; Marcussen, C.; Funck, T.; Jakobsson, M.; Hell, B.

    2010-12-01

    During the last several years new bathymetric, seismic reflection and refraction profiles have been collected on the Lomonosov Ridge, a feature whose bathymetric expression is 1700 km long and 50-200 km across. Compiling of data from various organizations provides a more complete data base for describing and interpreting the geological history of this unique ridge that crossed the Arctic Ocean from the continental margin of North America (north of Ellesmere Island and Greenland) to the continental margin of Russia creating the Eurasia and Amerasia basins. The Lomonosov Ridge has been described as a double-sided continental margin. Although the conjugate margin on the Eurasia Basin is accepted to be the margin of the Barents and Kara seas, that on the Amerasia Basin side is more difficult to locate. Near the junction of the Ridge with the North American continental margin, new bathymetric data more accurately describe the transition and the variation in slopes on either side of the ridge. On the Eurasia Basin rifted margin, conjugate to the margin of the Barents Sea, many small elongate highs are seen that are not observed on the Amerasia side. The wide plateau on the Lomonosov Ridge near the North American margin has been crossed by short reflection profiles and longer deep refraction profiles. The crustal structure and magnetic signature suggest that the plateau has been altered by igneous intrusion. Between the Pole and the North American margin, based on the magnetic character and supported by a few seismic profiles the continental ridge seems to have been modified by volcanism. This is consistent with the distribution of the High Arctic large igneous province (HALIP) from Franz Josef Land, Svalbard and Greenland (on the conjugate margin prior to rifting) and in the Canadian Arctic Archipelago. The HALIP has a number of radiating dykes that are useful is for the reconstruction of the region prior to sea floor spreading. From the Pole to the Siberian margin of

  5. Ridge Orientations of the Ridge-Forming Unit, Sinus Meridiani, Mars-A Fluvial Explanation

    NASA Technical Reports Server (NTRS)

    Wilkinson, M. Justin; Herridge, A.

    2013-01-01

    Imagery and MOLA data were used in an analysis of the ridge-forming rock unit (RFU) exposed in Sinus Meridiani (SM). This unit shows parallels at different scales with fluvial sedimentary bodies. We propose the terrestrial megafan as the prime analog for the RFU, and likely for other members of the layered units. Megafans are partial cones of fluvial sediment, with radii up to hundreds of km. Although recent reviews of hypotheses for the RFU units exclude fluvial hypotheses [1], inverted ridges in the deserts of Oman have been suggested as putative analogs for some ridges [2], apparently without appreciating The wider context in which these ridges have formed is a series of megafans [3], a relatively unappreciated geomorphic feature. It has been argued that these units conform to the megafan model at the regional, subregional and local scales [4]. At the regional scale suites of terrestrial megafans are known to cover large areas at the foot of uplands on all continents - a close parallel with the setting of the Meridiani sediments at the foot of the southern uplands of Mars, with its incised fluvial systems leading down the regional NW slope [2, 3] towards the sedimentary units. At the subregional scale the layering and internal discontinuities of the Meridiani rocks are consistent, inter alia, with stacked fluvial units [4]. Although poorly recognized as such, the prime geomorphic environment in which stream channel networks cover large areas, without intervening hillslopes, is the megafan [see e.g. 4]. Single megafans can reach 200,000 km2 [5]. Megafans thus supply an analog for areas where channel-like ridges (as a palimpsest of a prior landscape) cover the intercrater plains of Meridiani [6]. At the local, or river-reach scale, the numerous sinuous features of the RFU are suggestive of fluvial channels. Cross-cutting relationships, a common feature of channels on terrestrial megafans, are ubiquitous. Desert megafans show cemented paleo-channels as inverted

  6. Polygonal Ridge Networks on Mars

    NASA Astrophysics Data System (ADS)

    Kerber, Laura; Dickson, James; Grosfils, Eric; Head, James W.

    2016-10-01

    Polygonal ridge networks, also known as boxwork or reticulate ridges, are found in numerous locations and geological contexts across Mars. While networks formed from mineralized fractures hint at hot, possibly life-sustaining circulating ground waters, networks formed by impact-driven clasting diking, magmatic dikes, gas escape, or lava flows do not have the same astrobiological implications. Distinguishing the morphologies and geological context of the ridge networks sheds light on their potential as astrobiological and mineral resource sites of interest. The most widespread type of ridge morphology is characteristic of the Nili Fossae and Nilosyrtis region and consists of thin, criss-crossing ridges with a variety of heights, widths, and intersection angles. They are found in ancient Noachian terrains at a variety of altitudes and geographic locations and may be a mixture of clastic dikes, brecciated dikes, and mineral veins. They occur in the same general areas as valley networks and ancient lake basins, but they are not more numerous where these features are concentrated, and can appear in places where they morphologies are absent. Similarly, some of the ridge networks are associated with hydrated mineral detections, but some occur in locations without detections. Smaller, light-toned ridges of variable widths have been found in Gale Crater and other rover sites and are interpreted to be smaller version of the Nili-like ridges, in this case formed by the mineralization of fractures. This type of ridge is likely to be found in many other places on Mars as more high-resolution data becomes available. Hellas Basin is host to a third type of ridge morphology consisting of large, thick, light-toned ridges forming regular polygons at several superimposed scales. While still enigmatic, these are most likely to be the result of sediment-filled fractures. The Eastern Medusae Fossae Formation contains large swaths of a fourth, previously undocumented, ridge network type

  7. Making priors a priority

    NASA Astrophysics Data System (ADS)

    Segall, Matthew; Chadwick, Andrew

    2010-12-01

    When we build a predictive model of a drug property we rigorously assess its predictive accuracy, but we are rarely able to address the most important question, "How useful will the model be in making a decision in a practical context?" To answer this requires an understanding of the prior probability distribution ("the prior") and hence prevalence of negative outcomes due to the property being assessed. In this perspective, we illustrate the importance of the prior to assess the utility of a model in different contexts: to select or eliminate compounds, to prioritise compounds for further investigation using more expensive screens, or to combine models for different properties to select compounds with a balance of properties. In all three contexts, a better understanding of the prior probabilities of adverse events due to key factors will improve our ability to make good decisions in drug discovery, finding higher quality molecules more efficiently.

  8. Constructing priors in synesthesia.

    PubMed

    van Leeuwen, Tessa M

    2014-01-01

    A new theoretical framework (PPSMC) applicable to synesthesia has been proposed, in which the discrepancy between the perceptual reality of (some) synesthetic concurrents and their subjective non-veridicality is being explained. The PPSMC framework stresses the relevance of the phenomenology of synesthesia for synesthesia research-and beyond. When describing the emergence and persistence of synesthetic concurrents under PPSMC, it is proposed that precise, high-confidence priors are crucial in synesthesia. I discuss the construction of priors in synesthesia.

  9. Lava rise ridges of the Toomba basalt flow, north Queensland, Australia

    NASA Astrophysics Data System (ADS)

    Whitehead, P. W.; Stephenson, P. J.

    1998-11-01

    Unusually long lava rises occur in the distal portion of the Toomba basalt flow, up to 120 km from the source. In the Lolworth creek region, three parallel lava rise ridges occur over a 6 km section. Two of these ridges are continuous for the entire 6 km. The ridges average 7 m in height and range from 35 m to 300 m in width. Lava inflation clefts are numerous, and lava rise pits also occur. Down flow, a single lava rise ridge, averaging 18 m high and up to 500 m wide, extends for a further 10 km. This ridge has a generally level surface with abrupt edges sloping between 45° and 90°. Accurate surveys across the ridges show that in some cases there has been some stretching of the surface, presumably prior to the formation of the prominent clefts. The ridges were formed from an initially thin flow that was inflated by a continuous layer of lava that underlay almost the entire width of each ridge, rather than by a system of lava tubes of more limited dimensions. Inflated material represents over 90% of the volume of the distal parts of the flow. Estimates of the time required to inflate the lava rise ridges range from 60 days to a year.

  10. The Mid-Ocean Ridge.

    ERIC Educational Resources Information Center

    Macdonald, Kenneth C.; Fox, Paul J.

    1990-01-01

    Described are concepts involved with the formation and actions of the Mid-Ocean Ridge. Sea-floor spreading, the magma supply model, discontinuities, off-axis structures, overlaps and deviation, and aquatic life are discussed. (CW)

  11. Growth of a tectonic ridge

    SciTech Connect

    Fleming, R.W.; Messerich, J.A.; Johnson, A.M.

    1997-12-31

    The 28 June 1992 Landers, California, earthquake of M 7.6 created an impressive record of surface rupture and ground deformation. Fractures extend over a length of more than 80 km including zones of right-lateral shift, steps in the fault zones, fault intersections and vertical changes. Among the vertical changes was the growth of a tectonic ridge described here. In this paper the authors describe the Emerson fault zone and the Tortoise Hill ridge including the relations between the fault zone and the ridge. They present data on the horizontal deformation at several scales associated with activity within the ridge and belt of shear zones and show the differential vertical uplifts. And, they conclude with a discussion of potential models for the observed deformation.

  12. Repeat ridge jumps associated with plume-ridge interaction, melt transport, and ridge migration

    NASA Astrophysics Data System (ADS)

    Mittelstaedt, Eric; Ito, Garrett; van Hunen, Jeroen

    2011-01-01

    Repeated shifts, or jumps, of mid-ocean ridge segments toward nearby hot spots can produce large, long-term changes to the geometry and location of the tectonic plate boundaries. Ridge jumps associated with hot spot-ridge interaction are likely caused by several processes including shear on the base of the plate due to expanding plume material as well as reheating of lithosphere as magma passes through it to feed off-axis volcanism. To study how these processes influence ridge jumps, we use numerical models to simulate 2-D (in cross section) viscous flow of the mantle, viscoplastic deformation of the lithosphere, and melt migration upward from the asthenospheric melting zone, laterally along the base of the lithosphere, and vertically through the lithosphere. The locations and rates that magma penetrates and heats the lithosphere are controlled by the time-varying accumulation of melt beneath the plate and the depth-averaged lithospheric porosity. We examine the effect of four key parameters: magmatic heating rate of the lithosphere, plate spreading rate, age of the seafloor overlying the plume, and the plume-ridge migration rate. Results indicate that the minimum value of the magmatic heating rate needed to initiate a ridge jump increases with plate age and spreading rate. The time required to complete a ridge jump decreases with larger values of magmatic heating rate, younger plate age, and faster spreading rate. For cases with migrating ridges, models predict a range of behaviors including repeating ridge jumps, much like those exhibited on Earth. Repeating ridge jumps occur at moderate magmatic heating rates and are the result of changes in the hot spot magma flux in response to magma migration along the base of an evolving lithosphere. The tendency of slow spreading to promote ridge jumps could help explain the observed clustering of hot spots near the Mid-Atlantic Ridge. Model results also suggest that magmatic heating may significantly thin the lithosphere

  13. Sinuous Ridges in Peta Crater, Mars

    NASA Astrophysics Data System (ADS)

    Parker, T. J.

    2011-03-01

    Peta Crater (21°S,351°E) contains a system of sinuous ridges similar to, but smaller than, the well-known Dorsa Argyre and Dorsa Argentea ridges. Recent CTX and HiRISE images of the Peta crater ridges is enabling a detailed examination of this confined system of ridges.

  14. Length Scales of Magmatic Segments at Intermediate and Fast Spreading Ridges

    NASA Astrophysics Data System (ADS)

    Boulahanis, B.; Carbotte, S. M.; Klein, E. M.; Smith, D. K.; Cannat, M.

    2014-12-01

    A synthesis of observations from fast and magmatically-robust intermediate spreading ridges suggest that fine-scale tectonic segments, previously classified as 3rd order, correspond with principle magmatic segments along these ridges, each with their own magmatic plumbing system in the crust and shallow mantle. In this study, we use multi-beam sonar data available for fast and intermediate spreading ridges to determine the length distribution of these segments for comparison with the primary segmentation of the ridge axis found at slower spreading ridges. A study of intermediate, slow and ultraslow-spreading ridges using global satellite-derived bathymetry indicates a dominant segment length of 53 km [Briais and Rabinowicz, J. Geophys. Res. 2002]. However, satellite-derived bathymetry cannot be used to identify fine-scale tectonic segmentation of fast and magmatically-robust intermediate spreading ridges due to the subdued low-relief expression of ridge-axis discontinuities along these spreading rates. This study focuses on the well-mapped regions of the East Pacific Rise between 13.35°S and 18°N, and the Galapagos Spreading Center between 85° and 95.38° W. We reexamine tectonic segmentation of the ridge axis previously identified in the literature and modify the locations of ridge-axis discontinuities defining segment ends in regions where modern multi-beam bathymetric data coverage has improved relative to that available in early studies. Discontinuities of first, second, and third order are used to define tectonic segment lengths. Initial results show a mean segment length of 42 km (standard deviation of 27 km) and a median of 33 km, with 85 segments studied, similar to the segment length distributions observed at slower spreading ridges. To further evaluate the hypothesis of principle magmatic segments, we also examine the relationship between fine-scale tectonic segmentation and properties of the crustal magmatic system imaged in prior seismic studies of

  15. Crosscutting relations and relative ages of ridges and faults in the Tharsis region of Mars

    NASA Technical Reports Server (NTRS)

    Watters, T. R.; Maxwell, T. A.

    1983-01-01

    The results of a detailed photogeologic analysis and classification of ridge-fault cross-cutting relationships on ridged plains units of the Tharsis region is reported. The problems involved in using the morphology of ridge-fault intersections to determine relative timing of structural events are discussed. The implications of using intersection angles as well as morphology to determine possible age relationships for the tectonic history of the region are presented. It is concluded that the major ridge-forming events in the Tharsis region were roughly coincident with, and possibly prior to, the extensional events that produced the faulting of the Tempe and Mareotis regions, the Coprates and Memnonia regions, and the rifting of the Valles Marineris. The compressional events that formed most of the ridges are restricted in time both by their relationship to regional extensional events and by the age of the units on which they formed.

  16. ENVIRONMENTAL BASELINE SURVEY REPORT FOR WEST BLACK OAK RIDGE, EAST BLACK OAK RIDGE, MCKINNEY RIDGE, WEST PINE RIDGE, AND PARCEL 21D IN THE VICINITY OF THE EAST TENNESSEE TECHNOLOGY PARK, OAK RIDGE, TENNESSEE

    SciTech Connect

    David A. King

    2012-11-29

    This environmental baseline survey (EBS) report documents the baseline environmental conditions of five land parcels located near the U.S. Department of Energy’s (DOE’s) East Tennessee Technology Park (ETTP), including West Black Oak Ridge, East Black Oak Ridge, McKinney Ridge, West Pine Ridge, and Parcel 21d. The goal is to obtain all media no-further-investigation (NFI) determinations for the subject parcels considering existing soils. To augment the existing soils-only NFI determinations, samples of groundwater, surface water, soil, and sediment were collected to support all media NFI decisions. The only updates presented here are those that were made after the original issuance of the NFI documents. In the subject parcel where the soils NFI determination was not completed for approval (Parcel 21d), the full process has been performed to address the soils as well. Preparation of this report included the detailed search of federal government records, title documents, aerial photos that may reflect prior uses, and visual inspections of the property and adjacent properties. Interviews with current employees involved in, or familiar with, operations on the real property were also conducted to identify any areas on the property where hazardous substances and petroleum products, or their derivatives, and acutely hazardous wastes may have been released or disposed. In addition, a search was made of reasonably obtainable federal, state, and local government records of each adjacent facility where there has been a release of any hazardous substance or any petroleum product or their derivatives, including aviation fuel and motor oil, and which is likely to cause or contribute to a release of any hazardous substance or any petroleum product or its derivatives, including aviation fuel or motor oil, on the real property. A radiological survey and soil/sediment sampling was conducted to assess baseline conditions of Parcel 21d that were not addressed by the soils-only NFI

  17. Carpenter Ridge Tuff, CO

    NASA Astrophysics Data System (ADS)

    Bachmann, Olivier; Deering, Chad D.; Lipman, Peter W.; Plummer, Charles

    2014-06-01

    The ~1,000 km3 Carpenter Ridge Tuff (CRT), erupted at 27.55 Ma during the mid-tertiary ignimbrite flare-up in the western USA, is among the largest known strongly zoned ash-flow tuffs. It consists primarily of densely welded crystal-poor rhyolite with a pronounced, highly evolved chemical signature (high Rb/Sr, low Ba, Zr, Eu), but thickly ponded intracaldera CRT is capped by a more crystal-rich, less silicic facies. In the outflow ignimbrite, this upper zone is defined mainly by densely welded crystal-rich juvenile clasts of trachydacite composition, with higher Fe-Ti oxide temperatures, and is characterized by extremely high Ba (to 7,500 ppm), Zr, Sr, and positive Eu anomalies. Rare mafic clasts (51-53 wt% SiO2) with Ba contents to 4,000-5,000 ppm and positive Eu anomalies are also present. Much of the major and trace-element variations in the CRT juvenile clasts can be reproduced via in situ differentiation by interstitial melt extraction from a crystal-rich, upper-crustal mush zone, with the trachydacite, crystal-rich clasts representing the remobilized crystal cumulate left behind by the melt extraction process. Late recharge events, represented by the rare mafic clasts and high-Al amphiboles in some samples, mixed in with parts of the crystal cumulate and generated additional scatter in the whole-rock data. Recharge was important in thermally remobilizing the silicic crystal cumulate by partially melting the near-solidus phases, as supported by: (1) ubiquitous wormy/sieve textures and reverse zoning patterns in feldspars and biotites, (2) absence of quartz in this very silicic unit stored at depths of >4-5 km, and (3) heterogeneous melt compositions in the trachydacite fiamme and mafic clasts, particularly in Ba, indicating local enrichment of this element due mostly to sanidine and biotite melting. The injection of hot, juvenile magma into the upper-crustal cumulate also imparted the observed thermal gradient to the deposits and the mixing overprint that

  18. Comparison of Ridges on Triton and Europa

    NASA Technical Reports Server (NTRS)

    Prockter, L. M.; Pappalardo, R. .

    2003-01-01

    Triton and Europa each display a variety of ridges and associated troughs. The resemblance of double ridges on these two satellites has been previously noted [R. Kirk, pers. comm.], but as yet, the similarities and differences between these feature types have not been examined in any detail. Triton s ridges, and Europa s, exhibit an evolutionary sequence ranging from isolated troughs, through doublet ridges, to complex ridge swaths [1, 2]. Comparison of ridges on Europa to those on Triton may provide insight into their formation on both satellites, and thereby have implications for the satellites' histories.

  19. HIGHLAND RIDGE ROADLESS AREA, NEVADA.

    USGS Publications Warehouse

    Whitebread, Donald H.; Brown, S. Don

    1984-01-01

    The mineral-resource potential of the Highland Ridge Roadless Area, Nevada was evaluated on the basis of results from field investigations. One area along the west border of the Highland Ridge Roadless Area has substantiated mineral-resource potential for tungsten. Several other areas are classed as having probable mineral-resource potential, based mainly upon anomalously high values of tungsten, lead, silver, and zinc in concentrates of stream sediments. Most of the roadless area is underlain by rocks in the upper plate of the Snake Range decollement, and is considered to have little promise for the occurrence of mineral resources. No energy resource potential was identified in the area.

  20. Near-ridge seamount chains in the northeastern Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Clague, David A.; Reynolds, Jennifer R.; Davis, Alicé S.

    2000-07-01

    High-resolution bathymetry and side-scan data of the Vance, President Jackson, and Taney near-ridge seamount chains in the northeast Pacific were collected with a hull-mounted 30-kHz sonar. The central volcanoes in each chain consist of truncated cone-shaped volcanoes with steep sides and nearly flat tops. Several areas are characterized by frequent small eruptions that result in disorganized volcanic regions with numerous small cones and volcanic ridges but no organized truncated conical structure. Several volcanoes are crosscut by ridge-parallel faults, showing that they formed within 30-40 km of the ridge axis where ridge-parallel faulting is still active. Magmas that built the volcanoes were probably transported through the crust along active ridge-parallel faults. The volcanoes range in volume from 11 to 187 km3, and most have one or more multiple craters and calderas that modify their summits and flanks. The craters (<1 km diameter) and calderas (>1 km diameter) range from small pit craters to calderas as large as 6.5×8.5 km, although most are 2-4 km across. Crosscutting relationships commonly show a sequence of calderas stepping toward the ridge axis. The calderas overlie crustal magma chambers at least as large as those that underlie Kilauea and Mauna Loa Volcanoes in Hawaii, perhaps 4-5 km in diameter and ˜1-3 km below the surface. The nearly flat tops of many of the volcanoes have remnants of centrally located summit shields, suggesting that their flat tops did not form from eruptions along circumferential ring faults but instead form by filling and overflowing of earlier large calderas. The lavas retain their primitive character by residing in such chambers for only short time periods prior to eruption. Stored magmas are withdrawn, probably as dikes intruded into the adjacent ocean crust along active ridge-parallel faults, triggering caldera collapse, or solidified before the next batch of magma is intruded into the volcano, probably 1000-10,000 years

  1. THE EQUATION AT OAK RIDGE.

    ERIC Educational Resources Information Center

    MORRELL, KEN

    THE STEPS TAKEN TO DESEGREGATE THE OAK RIDGE, TENN., SCHOOLS ARE DESCRIBED IN THIS ARTICLE. ONE ELEMENTARY SCHOOL, SEGREGATED BECAUSE OF RESIDENTIAL PATTERNS, WAS CLOSED AND ITS STUDENTS REDISTRIBUTED AMONG OTHER SCHOOLS IN THE CITY. UNDER THE INITIATIVE OF THE SCHOOL BOARD, THIS PLAN WENT INTO EFFECT IN THE FALL OF 1967 AND IS SAID TO HAVE…

  2. Measurement and computation of movement of bromide ions and carbofuran in ridged humic-sandy soil.

    PubMed

    Leistra, Minze; Boesten, Jos J T I

    2010-07-01

    Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. Rainfall was supplemented by sprinkler irrigation. The distribution of the substances in the soil profile of the ridges and furrows was measured on three dates in the potato growing season. Separate ridge and furrow systems were simulated by using the pesticide emission assessment at regional and local scales (PEARL) model for pesticide behavior in soil-plant systems. The substances travelled deeper in the furrow soil than in the ridge soil, because of runoff from the ridges to the furrows. At 19 days after application, the peak of the bromide distribution was measured to be in the 0.1-0.2 m layer of the ridges, while it was in the 0.3-0.5 m layer of the furrows. After 65 days, the peak of the carbofuran distribution in the ridge soil was still in the 0.1 m top layer, while the pesticide was rather evenly distributed in the top 0.6 m of the furrow soil. The wide ranges in concentration measured with depth showed that preferential water flow and substance transport occurred in the sandy soil. Part of the bromide ion distribution was measured to move faster in soil than the computed wave. The runoff of water and pesticide from the ridges to the furrows, and the thinner root zone in the furrows, are expected to increase the risk of leaching to groundwater in ridged fields, in comparison with more level fields.

  3. Measurement and Computation of Movement of Bromide Ions and Carbofuran in Ridged Humic-Sandy Soil

    PubMed Central

    Boesten, Jos J. T. I.

    2009-01-01

    Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. Rainfall was supplemented by sprinkler irrigation. The distribution of the substances in the soil profile of the ridges and furrows was measured on three dates in the potato growing season. Separate ridge and furrow systems were simulated by using the pesticide emission assessment at regional and local scales (PEARL) model for pesticide behavior in soil–plant systems. The substances travelled deeper in the furrow soil than in the ridge soil, because of runoff from the ridges to the furrows. At 19 days after application, the peak of the bromide distribution was measured to be in the 0.1–0.2 m layer of the ridges, while it was in the 0.3–0.5 m layer of the furrows. After 65 days, the peak of the carbofuran distribution in the ridge soil was still in the 0.1 m top layer, while the pesticide was rather evenly distributed in the top 0.6 m of the furrow soil. The wide ranges in concentration measured with depth showed that preferential water flow and substance transport occurred in the sandy soil. Part of the bromide ion distribution was measured to move faster in soil than the computed wave. The runoff of water and pesticide from the ridges to the furrows, and the thinner root zone in the furrows, are expected to increase the risk of leaching to groundwater in ridged fields, in comparison with more level fields. PMID:20041324

  4. Status of Blue Ridge Reservoir

    SciTech Connect

    Not Available

    1990-09-01

    This is one in a series of reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Blue Ridge Reservoir summarizes reservoir and watershed characteristics, reservoir uses and use impairments, water quality and aquatic biological conditions, and activities of reservoir management agencies. This information was extracted from the most current reports and data available, as well as interview with water resource professionals in various federal, state, and local agencies. Blue Ridge Reservoir is a single-purpose hydropower generating project. When consistent with this primary objective, the reservoir is also operated to benefit secondary objectives including water quality, recreation, fish and aquatic habitat, development of shoreline, aesthetic quality, and other public and private uses that support overall regional economic growth and development. 8 refs., 1 fig.

  5. Structural processes at slow-spreading ridges.

    PubMed

    Mutter, J C; Karson, J A

    1992-07-31

    Slow-spreading (<35 millimeters per year) mid-ocean ridges are dominated by segmented, asymmetric, rifted depressions like continental rifts. Fast-spreading ridges display symmetric, elevated volcanic edifices that vary in shape and size along axis. Deep earthquakes, major normal faults, and exposures of lower crustal rocks are common only along slow-spreading ridges. These contrasting features suggest that mechanical deformation is far more important in crustal formation at slow-spreading ridges than at fast-spreading ridges. New seismic images suggest that the nature and scale of segmentation of slow-spreading ridges is integral to the deformational process and not to magmatic processes that may control segmentation on fast-spreading ridges.

  6. Oak Ridge National Laboratory Review

    SciTech Connect

    Krause, C.; Pearce, J.; Zucker, A.

    1992-01-01

    This report presents brief descriptions of the following programs at Oak Ridge National Laboratory: The effects of pollution and climate change on forests; automation to improve the safety and efficiency of rearming battle tanks; new technologies for DNA sequencing; ORNL probes the human genome; ORNL as a supercomputer research center; paving the way to superconcrete made with polystyrene; a new look at supercritical water used in waste treatment; and small mammals as environmental monitors.

  7. Ridge Preservation for Implant Therapy: a Review of the Literature

    PubMed Central

    Tomlin, Elizabeth M; Nelson, Shelby J; Rossmann, Jeffrey A

    2014-01-01

    Healing of the extraction socket after tooth removal involves retention of the blood clot followed by a sequence of events that lead to changes in the alveolar process in a three dimensional fashion. This normal healing event results in a minimal loss of vertical height (around 1 mm), but a substantial loss of width in the buccal-lingual plane (4-6 mm). During the first three months following extraction that loss has been shown to be significant and may result in both a hard tissue and soft tissue deformity affecting the ability to restore the site with acceptable esthetics. Procedures that reduce the resorptive process have been shown to be predictable and potentially capable of eliminating secondary surgery for site preparation when implant therapy is planned. The key element is prior planning by the dental therapist to act at the time of extraction to prevent the collapse of the ridge due to the loss of the alveolus. Several techniques have been employed as ridge preservation procedures involving the use of bone grafts, barrier membranes and biologics to provide a better restorative outcome. This review will explore the evidence behind each technique and their efficacy in accomplishing site preparation. The literature does not identify a single technique as superior to others; however, all accepted therapeutic procedures for ridge preservation have been shown to be more effective than blood clot alone in randomized controlled studies. PMID:24893595

  8. Mechanisms of Basalt-plains Ridge Formation

    NASA Technical Reports Server (NTRS)

    Watters, T. R.; Maxwell, T. A.

    1985-01-01

    The morphologic similarities between the Columbia Plateau ridges and ridges on the Moon, Mercury and Mars form a strong basis for the interpretation of basalt-plains ridges as compressional folds. The basalt-plains ridges appear to have formed on competent flood basalt units deformed at the surface with essentially no confining pressure. Estimates of compressive strain for planetary ridges range from a few tenths of a percent on the Moon to up to 0.4% on Mars, to as high as 35% for Columbia Plateau folds with associated thrust faults. Such values have strong implications for both deformational mechanisms as well as for the source of stress. Deformational mechanisms that will attempt to account for the morphology, fold geometry, possible associated thrust faulting and regular spacing of the basalt-plains ridges on the terrestrial planets are under investigation.

  9. Constitutive Parameter Measurement Using Double Ridge Waveguide

    DTIC Science & Technology

    2013-03-01

    CONSTITUTIVE PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE THESIS Nathan J. Lehman, Captain, USAF AFIT-ENG-13-M-30 DEPARTMENT OF THE AIR FORCE...copyright protection in the United States. AFIT-ENG-13-M-30 CONSTITUTIVE PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE THESIS Presented to the Faculty...PARAMETER MEASUREMENT USING DOUBLE RIDGE WAVEGUIDE Nathan J. Lehman, B.S.E.E. Captain, USAF Approved: Michael Havrilla, PhD (Chairman) Maj Milo Hyde, PhD

  10. The Importance of Prior Knowledge.

    ERIC Educational Resources Information Center

    Cleary, Linda Miller

    1989-01-01

    Recounts a college English teacher's experience of reading and rereading Noam Chomsky, building up a greater store of prior knowledge. Argues that Frank Smith provides a theory for the importance of prior knowledge and Chomsky's work provided a personal example with which to interpret and integrate that theory. (RS)

  11. Work plan for the High Ranking Facilities Deactivation Project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1996-03-01

    The High Ranking Facilities Deactivation Project (HRFDP), commissioned by the US Department of Energy Nuclear Materials and Facility Stabilization Program, is to place four primary high-risk surplus facilities with 28 associated ancillary facilities at Oak Ridge National Laboratory in a safe, stable, and environmentally sound condition as rapidly and economically as possible. The facilities will be deactivated and left in a condition suitable for an extended period of minimized surveillance and maintenance (S and M) prior to decontaminating and decommissioning (D and D). These four facilities include two reactor facilities containing spent fuel. One of these reactor facilities also contains 55 tons of sodium with approximately 34 tons containing activated sodium-22, 2.5 tons of lithium hydride, approximately 100 tons of potentially contaminated lead, and several other hazardous materials as well as bulk quantities of contaminated scrap metals. The other two facilities to be transferred include a facility with a bank of hot cells containing high levels of transferable contamination and also a facility containing significant quantities of uranyl nitrate and quantities of transferable contamination. This work plan documents the objectives, technical requirements, and detailed work plans--including preliminary schedules, milestones, and conceptual FY 1996 cost estimates--for the Oak Ridge National Laboratory (ORNL). This plan has been developed by the Environmental Restoration (ER) Program of Lockheed Martin Energy Systems (Energy Systems) for the US Department of Energy (DOE) Oak Ridge Operations Office (ORO).

  12. Geo-Morphological Analyses of the Gakkel Ridge and the Southwest Indian Ridge

    NASA Astrophysics Data System (ADS)

    Dorschel, B.; Schlindwein, V. S. N.; Eagles, G.

    2014-12-01

    The Gakkel Ridge in the Arctic Ocean and the Southwest Indian Ridge in the Southwest Indian Ocean between Africa and Antarctica are ultraslow-spreading (<20 mm yr-1) mid ocean ridges. This type of mid ocean ridge has distinct geo-morphologies that are influenced by the slow rate of plate divergence and by mantle potential temperature, which control the processes (peridotite diapirism and intersticial melt migration) by which material rises to fill the space vacated by plate divergence. These ridges are characterised by non-orthogonal spreading. Transform faults, typical of faster spreading mid ocean ridges, are far less common at ultraslow spreading mid ocean ridges. Thus in return, detailed geo-statistical analyses of the geo-morphology of ultraslow-spreading mid ocean ridges can provide valuable information towards a better understanding of these slowest of spreading ridges. We have generated high resolution bathymetric grids for the Gakkel and Southwest Indian ridges based on high resolution multibeam echosounder data from various expeditions with RV Polarstern. On the basis of these grids, geo-statistical analyses allow for an assessment of the geo-morphological elements of the ridges on various scales. The results of these analyses show that, approximately 200 km long medium-scale sections of the ridges can be characterised by the lengths and orientations of the short-scale (hundreds of meters to tens of kilometres) ridges and troughs. The geomorphologies of short-scale ridges and troughs situated at the junctions between medium scale sections often exhibit a mixture of the geomorphological elements seen in the neighbouring sections. These geo-morphological patterns provide insights into the overall spreading-geometry along the Gakkel Ridge and the Southwest Indian Ridge.

  13. Executive Order 12941 Implementation at the Oak Ridge National Laboratory

    SciTech Connect

    Hunt, R.J.; Kroon, R.J.; Shaffer, K.E.

    1998-08-01

    Congress enacted the Earthquake Hazards Reduction Act of 1977 (Public Law 95-124, as amended) to reduce risks to life and property from future earthquakes in the US. To implement the provisions of the Act, the Interagency Committee on Seismic Safety in Construction (ICSSC) was chartered. Approximately thirty Federal agencies, including the Department of Energy (DOE), participate in the ICSSC. The ICSSC is chaired by the National Institute of Standards (NIST) which also provides the technical secretariat. EO 12941, Seismic Safety of Existing Federally Owned or Leased Buildings, were prepared and issued by the ICSSC to reduce the vulnerability to buildings owned or leased by agencies or departments for Federal use. This report documents the implementation of EO 12941 at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. ORNL is managed and operated by Lockheed Martin Energy Research, Inc. (LMER) for the DOE-Oak Ridge Operations Office (DOE-ORO). The ORNL building inventory includes buildings that are physically located at ORNL, East Tennessee Technology Park (ETTP), and the Oak Ridge Y-12 Plant. This report addresses buildings physically located at the ORNL plant site. ORNL buildings located at ETTP and Y-12 plant sites will be included in the EO 12941 implementation reports for those sites. The scope of this effort included revising the building inventory for ORNL that was prepared prior to the development of the DOE management plan, evaluating owned buildings not exempt from the requirements of EO 12941, estimating the costs associated with the rehabilitation of vulnerable non-exempt buildings, and preparing this report in the TR-17 prescribed format (CNPE 1996). These activities were performed in accordance with the DOE management plan and as applicable, Phase I - Screening Guidelines To Determine The Structures Exempt From Executive Order 12941 (CNPE 1995).

  14. Oak Ridge Reservation annual site environmental report for 2008

    SciTech Connect

    none,

    2009-09-01

    The Oak Ridge Reservation (ORR) consists of three major government-owned, contractor-operated facilities: the Y-12 National Security Complex, Oak Ridge National Laboratory, and East Tennessee Technology Park. The ORR was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced materials for the first atomic bombs. The reservation’s role has evolved over the years, and it continues to adapt to meet the changing defense, energy, and research needs of the United States. Both the work carried out for the war effort and subsequent research, development, and production activities have involved, and continue to involve, the use of radiological and hazardous materials. The Oak Ridge Reservation Annual Site Environmental Report and supporting data are available at http://www.ornl.gov/sci/env_rpt or from the project director. This document is prepared annually to summarize environmental activities, primarily environmental monitoring activities, on the Oak Ridge Reservation (ORR) and within the ORR surroundings. The document fulfills the requirement of Department of Energy (DOE) Order 231.1A, Environment, Safety and Health Reporting, for an annual summary of environmental data to characterize environmental performance. The environmental monitoring criteria are described in DOE Order 450.1A, Environmental Protection Program. The results summarized in this report are based on data collected prior to and through 2008. This report is not intended to provide the results of all sampling on the ORR. Additional data collected for other site and regulatory purposes, such as environmental restoration/remedial investigation reports, waste management characterization sampling data, and environmental permit compliance data, are presented in other documents that have been prepared in accordance with applicable DOE guidance and/or laws and are referenced herein as appropriate. Corrections to the report for the previous year are found in Appendix

  15. Final deactivation project report on the Integrated Process Demonstration Facility, Building 7602 Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1997-09-01

    The purpose of this report is to document the condition of the Integrated Process Demonstration Facility (Building 7602) at Oak Ridge National Laboratory (ORNL) after completion of deactivation activities by the High Ranking Facilities Deactivation Project (HRFDP). This report identifies the activities conducted to place the facility in a safe and environmentally sound condition prior to transfer to the U.S. Department of Energy (DOE) Environmental Restoration EM-40 Program. This report provides a history and description of the facility prior to commencing deactivation activities and documents the condition of the building after completion of all deactivation activities. Turnover items, such as the Post-Deactivation Surveillance and Maintenance (S&M) Plan, remaining hazardous and radioactive materials inventory, radiological controls, Safeguards and Security, and supporting documentation provided in the Office of Nuclear Material and Facility Stabilization Program (EM-60) Turnover package are discussed.

  16. Emergency preparedness at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Skipper, M.N.

    1990-03-01

    Emergency preparedness for industry was commonly believed to be an essential responsibility on the part of management. Therefore, this study was conducted to research and accumulate information and data on emergency preparedness at Oak Ridge National Laboratory (ORNL). The objective of this study was to conduct a thorough evaluation of emergency preparedness knowledge among employees to determine if they were properly informed or if they needed more training. Also, this study was conducted to provide insight to management as to what their responsibility was concerning this training. To assess employee emergency preparedness knowledge, a questionnaire was developed and administered to 100 employees at ORNL. The data was analyzed using frequencies and percentages of response and was displayed through the use of graphs within the report. 22 refs., 22 figs.

  17. Depth and Morphology of Wrinkle Ridge Detachments at Solis Planum, Mars

    NASA Astrophysics Data System (ADS)

    Colton, S. L.; Ferrill, D. A.; Smart, K. J.

    2005-12-01

    Wrinkle ridges -- long, linear to sinuous anticlines separated by relatively broad, flat synclinal valleys -- are a fundamental component of Martian geomorphology. The anticlinal crests show variable morphologies, but are often characterized by weak to strong asymmetry with variable vergence directions between adjacent ridges and along strike for any given ridge. Although wrinkle ridges are typically interpreted as contractional features, there is ongoing debate about their underlying structure and whether thrust faults penetrate to tens of kilometers of depth ("thick-skinned shortening") or sole into a detachment in the upper few kilometers of the Martian crust ("thin-skinned shortening"). Previous workers have estimated depth to the detachment horizon using a variety of methods including gravity inversion, geometry of crater-ridge intersections, mechanical modeling, and geometric modeling. Here we use a well-established terrestrial technique to calculate depth to the detachment horizon for wrinkle ridges in the Solis Planum region of Mars. We interpolate topographic profiles perpendicular to the regional trend of wrinkle ridges from Mars Orbiter Laser Altimeter (MOLA) Mission Experiment Gridded Data Record (MEGDR) altimetry data, set vertical reference lines on both sides of the ridge that define the limits of our measurement range, estimate the topographic surface prior to wrinkle ridge formation, and calculate the area uplifted above the original topographic surface. Dividing this excess area by the amount of shortening (the topographic profile length minus the length prior to deformation), provides depth to detachment. We calibrate the results with profiles from the less spatially-extensive but greater along-track density MOLA Precision Experiment Data Record (PEDR). Additional topographic and structural interpretation and analysis of wrinkle ridge morphology are conducted with Mars Orbiter Camera (MOC), Thermal Emission Imaging System (THEMIS), and High

  18. Student Health Services at Orchard Ridge.

    ERIC Educational Resources Information Center

    Nichols, Don D.

    This paper provides a synoptic review of student health services at the community college level while giving a more detailed description of the nature of health services at Orchard Ridge, a campus of Oakland Community College. The present College Health Service program provides for a part-time (24 hrs./wk.) nurse at Orchard Ridge. A variety of…

  19. Ridges and tidal stress on Io

    USGS Publications Warehouse

    Bart, G.D.; Turtle, E.P.; Jaeger, W.L.; Keszthelyi, L.P.; Greenberg, R.

    2004-01-01

    Sets of ridges of uncertain origin are seen in twenty-nine high-resolution Galileo images, which sample seven locales on Io. These ridges are on the order of a few kilometers in length with a spacing of about a kilometer. Within each locale, the ridges have a consistent orientation, but the orientations vary from place to place. We investigate whether these ridges could be a result of tidal flexing of Io by comparing their orientations with the peak tidal stress orientations at the same locations. We find that ridges grouped near the equator are aligned either north-south or east-west, as are the predicted principal stress orientations there. It is not clear why particular groups run north-south and others east-west. The one set of ridges observed far from the equator (52?? S) has an oblique azimuth, as do the tidal stresses at those latitudes. Therefore, all observed ridges have similar orientations to the tidal stress in their region. This correlation is consistent with the hypothesis that tidal flexing of Io plays an important role in ridge formation. ?? 2004 Elsevier Inc. All rights reserved.

  20. Tectonics and magmatism of ultraslow spreading ridges

    NASA Astrophysics Data System (ADS)

    Dubinin, E. P.; Kokhan, A. V.; Sushchevskaya, N. M.

    2013-05-01

    The tectonics, structure-forming processes, and magmatism in rift zones of ultraslow spreading ridges are exemplified in the Reykjanes, Kolbeinsey, Mohns, Knipovich, Gakkel, and Southwest Indian ridges. The thermal state of the mantle, the thickness of the brittle lithospheric layer, and spreading obliquety are the most important factors that control the structural pattern of rift zones. For the Reykjanes and Kolbeinsey ridges, the following are crucial factors: variations in the crust thickness; relationships between the thicknesses of its brittle and ductile layers; width of the rift zone; increase in intensity of magma supply approaching the Iceland thermal anomaly; and spreading obliquety. For the Knipovich Ridge, these are its localization in the transitional zone between the Gakkel and Mohns ridges under conditions of shear and tensile stresses and multiple rearrangements of spreading; nonorthogonal spreading; and structural and compositional barrier of thick continental lithosphere at the Barents Sea shelf and Spitsbergen. The Mohns Ridge is characterized by oblique spreading under conditions of a thick cold lithosphere and narrow stable rift zone. The Gakkel and the Southwest Indian ridges are distinguished by the lowest spreading rate under the settings of the along-strike variations in heating of the mantle and of a variable spreading geometry. The intensity of endogenic structure-forming varies along the strike of the ridges. In addition to the prevalence of tectonic factors in the formation of the topography, magmatism and metamorphism locally play an important role.

  1. Cedar Ridge Camp: Using the Local Environment

    ERIC Educational Resources Information Center

    Burke, Grayson

    2007-01-01

    In 2007 Cedar Ridge Camp opened for its first season as a traditional co-ed summer camp and year-round outdoor education and recreation centre. The mission would centre on creating a program that would encourage personal development and growth through a shared outdoor experience. Cedar Ridge's main goals were to promote the formation of close…

  2. Recruiting for Prior Service Market

    DTIC Science & Technology

    2008-06-01

    perceptions, expectations and issues for re-enlistment • Develop potential marketing and advertising tactics and strategies targeted to the defined...01 JUN 2008 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Recruiting for Prior Service Market 5a. CONTRACT NUMBER 5b. GRANT...Command First Handshake to First Unit of Assignment An Army of One Proud to Be e e to Serve Recruiting for Prior Service Market MAJ Eric Givens / MAJ Brian

  3. Transverse dune trailing ridges and vegetation succession

    NASA Astrophysics Data System (ADS)

    Hesp, Patrick A.; ‘Marisa' Martinez, M. L.

    2008-07-01

    We describe the evolution of, and vegetation succession on, a previously undescribed landform: transverse dune trailing ridges at El Farallón transgressive dunefield in the state of Veracruz, Mexico. Three-dimensional clinometer/compass and tape topographic surveys were conducted in conjunction with 1 m 2 contiguous percent cover and presence/absence vegetation survey transects at eight locations across two adjacent trailing ridges. At the study site, and elsewhere, the transverse dune trailing ridges are formed by vegetation colonization of the lateral margins of active transverse, barchanoidal transverse, and aklé or network dunes. For simplicity, all trailing ridges formed from these dune types are referred to as transverse dune trailing ridges. Because there are several transverse dunes in the dunefield, multiple trailing ridges can be formed at one time. Two adjacent trailing ridges were examined. The shortest length ridge was 70 m long, and evolving from a 2.5 m-high transverse dune, while the longer ridge was 140 m long, and evolving from an 8 m-high dune. Trailing ridge length is a proxy measure of ridge age, since the longer the ridge, the greater the length of time since initial formation. With increasing age or distance upwind, species diversity increased, as well as species horizontal extent and percent cover. In turn, the degree of bare sand decreased. Overall, the data indicate a successional trend in the vegetation presence and cover with increasing age upwind. Those species most tolerant to burial ( Croton and Palafoxia) begin the process of trailing ridge formation. Ipomoea and Canavalia are less tolerant to burial and also are typically the next colonizing species. Trachypogon does not tolerate sand burial or deposition very well and only appears after significant stabilization has taken place. The ridges display a moderately defined successional sequence in plant colonization and percentage cover with time (and upwind distance). They are

  4. Hydroforming Applications at Oak Ridge

    SciTech Connect

    bird, e.l.; ludtka, g.m.

    1999-03-10

    Hydroforming technology is a robust forming process that produces components with high precision and complexity. The goal of this paper is to present a brief description of the sheet hydroforming process with respect to the authors' experience and capabilities. Following the authors' discussion of the sheet-metal forming application, the tubular hydroforming process is described in the context of one of our technology development programs with an automotive industrial partner. After that is a summary of the tubular hydroforming advisor (expert system) development activity, which was a significant part of this overall program based on previous experience in developing a design and manufacturing support hydroforming advisor for the Oak Ridge Y-12 Plant's weapons-component manufacturing needs. Therefore, this paper is divided into three sections: (1) Hydroforming of Stainless Steel Parts, (2) Tubular Hydroforming, and (3) Components of a Tubular Hydroforming Advisor.

  5. 1. GENERAL VIEW OF ENTRANCE TO BLUE RIDGE TUNNEL (LEFT) ...

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

    1. GENERAL VIEW OF ENTRANCE TO BLUE RIDGE TUNNEL (LEFT) FROM SOUTHEAST. ORIGINAL BLUE RIDGE R.R. (CROZET) TUNNEL IS VISIBLE AT RIGHT. - Chesapeake & Ohio Railroad, Blue Ridge Tunnel, Highway 250 at Rockfish Gap, Afton, Nelson County, VA

  6. Plume-ridge interaction: Shaping the geometry of mid-ocean ridges

    NASA Astrophysics Data System (ADS)

    Mittelstaedt, Eric L.

    Manifestations of plume-ridge interaction are found across the ocean basins. Currently there are interactions between at least 21 hot spots and nearby ridges along 15--20% of the global mid-ocean ridge network. These interactions produce a number of anomalies including the presence of elevated topography, negative gravity anomalies, and anomalous crustal production. One form of anomalous crustal production is the formation of volcanic lineaments between hotspots and nearby mid-ocean ridges. In addition, observations indicate that mantle plumes tend to "capture" nearby mid-ocean ridges through asymmetric spreading, increased ridge propagation, and discrete shifts of the ridge axis, or ridge jumps. The initiation of ridge jumps and the formation of off-axis volcanic lineaments likely involve similar processes and may be closely related. In the following work, I use theoretical and numerical models to quantify the processes that control the formation of volcanic lineaments (Chapter 2), the initiation of mid-ocean ridge jumps associated with lithospheric heating due to magma passing through the plate (Chapter 3), and the initiation of jumps due to an upwelling mantle plume and magmatic heating governed by melt migration (Chapter 4). Results indicate that lineaments and ridge jumps associated with plume-ridge interaction are most likely to occur on young lithosphere. The shape of lineaments on the seafloor is predicted to be controlled by the pattern of lithospheric stresses associated with a laterally spreading, near-ridge mantle plume. Ridge jumps are likely to occur due to magmatic heating alone only in lithosphere ˜1Myr old, because the heating rate required to jump increases with spreading rate and plate age. The added effect of an upwelling plume introduces competing effects that both promote and inhibit ridge jumps. For models where magmatic heating is controlled by melt migration, repeat ridge jumps are predicted to occur as the plume and ridge separate, but

  7. The "pressures" of being a ridge

    NASA Astrophysics Data System (ADS)

    Fleeman, K.; Scott, J. L.; Barton, M.

    2015-12-01

    As part of a larger project aimed at understanding the magma plumbing systems and magmatic processes responsible for crust formation at divergent plate margins, we have begun a study of the Galapagos Spreading Center (GSC), an intermediate spreading ridge off the west coast of South America and connected to the East Pacific Rise. This ridge is of interest because it passes close to the Galapagos Islands, allowing the effects of a mantle plume on sub-ridge processes and magma plumbing systems to be examined. In addition, the effects of ridge-ridge intersection, ridge propagation, and ridge offsets by transform faults on magma evolution can be examined. Published compositional data for glasses collected along the ridge were used to calculate pressures of partial crystallization and to examine variations in magma chemistry along the ridge. To aid interpretation of the results, the ridge was divided into 12 segments based on sample distribution and the occurrence of ridge offsets. Calculated pressures for most segments range from 100 and 300 MPa, and indicate depths of partial crystallization of ~3-9 km. This suggests that accretion occurs mostly near the base of the crust. However, the range of pressures for some segments is relatively large with maximum calculated values of 500-750 MPa. For example, near the major transform fault at ~85OW, the calculated maximum pressure is 741 MPa and the average pressure is ~ 300 MPa. We consider it unlikely that the calculated high pressures represent the true pressure of partial crystallization, and suggest that the compositions of some magmas result from processes other than simple crystallization. Correlations between Pressure and MgO, between Na2O and MgO, P2O5 and K2O, and between Na8 and longitude suggest that the processes operating beneath this ridge are complex. Near the transform fault for example, MgO vs Pressure shows a negative correlation with an R2 value of 0.546. Such trends are inconsistent with magma evolution

  8. SRTM Anaglyph: Wheeler Ridge, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Wheeler Ridge and vicinity, California, is a site of major tectonic activity, both historically and over recent geologic time. The epicenter of the 7.5 magnitude Kern County earthquake occurred here on July 21,1952, and numerous geologic and topographic features indicate rapid geologic processes. The ridge itself (upper-right center) is a geologic fold that is growing out of the southern San Joaquin Valley. A prominent 'wind gap,' now used for passage of the California aquaduct (with the aid of a pumping station), is evidence that the ridge grew faster than tranversing streams could erode down. Nearby abrupt and/or landslid mountain fronts similarly indicate a vigorous tectonic setting here, just north of the San Andreas fault. The Interstate 5 freeway can be seen crossing agricultural fields on the right and entering the very rugged and steep Grapevine Canyon toward the bottom.

    This anaglyph was generated by first draping a Landsat satellite image over a preliminary topographic map from the Shuttle Radar Topography Mission (SRTM), then generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30 meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive.

    The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect

  9. The structure of mid-ocean ridges

    NASA Technical Reports Server (NTRS)

    Solomon, Sean C.; Toomey, Douglas R.

    1992-01-01

    Recent research results on the structure of midocean ridges are reviewed. The new view of ridge-axis crustal structure obtained from high-resolution seismology is reviewed, emphasizing the variation of that structure with spreading rate and along-axis at a given spreading rate. Recent results on upper mantle structure beneath ridges are examined, including variations with seafloor age, indications from anisotropy for directions of mantle flow, and long-wavelength along-axis variations in structure and their implications for lateral heterogeneity in mantle temperature and composition.

  10. Controls on melting at spreading ridges from correlated abyssal peridotite - mid-ocean ridge basalt compositions

    NASA Astrophysics Data System (ADS)

    Regelous, Marcel; Weinzierl, Christoph G.; Haase, Karsten M.

    2016-09-01

    Variations in the volume and major element composition of basalt erupted along the global mid-ocean ridge system have been attributed to differences in mantle potential temperature, mantle composition, or plate spreading rate and lithosphere thickness. Abyssal peridotites, the residues of mantle melting beneath mid-ocean ridges, provide additional information on the melting process, which could be used to test these hypotheses. We compiled a global database of abyssal peridotite compositions averaged over the same ridge segments defined by Gale et al. (2013). In addition, we calculated the distance of each ridge segment to the nearest hotspots. We show that Cr# in spinel in abyssal peridotites is negatively correlated with Na90 in basalts from the same ridge segments on a global scale. Ridge segments that erupt basalts apparently produced by larger degrees of mantle melting are thus underlain by peridotites from which large amounts of melt have been extracted. We find that near-ridge hotspots have a more widespread influence on mid-ocean ridge basalt (MORB) composition and ridge depth than previously thought. However, when these hotspot-influenced ridge segments are excluded, the remaining segments show clear relationships between MORB composition, peridotite composition, and ridge depth with spreading rate. Very slow-spreading ridges (<20 mm/yr) are deeper, erupt basalts with higher Na90, Al90, K90/Ti90, and lower Fe90, Ca90/Al90, and expose peridotites with lower Cr# than intermediate and fast-spreading ridges. We show that away from hotspots, the spreading-rate dependence of the maximum degree of mantle melting inferred from Cr# in peridotites (FM) and the bulk degree of melting inferred from Na90 in basalts (FB) from the same ridge segments is unlikely to be due to variations in mantle composition. Nor can the effects of dynamic mantle upwelling or incomplete melt extraction at low spreading rates satisfactorily explain the observed compositions of abyssal

  11. The shallow structure of the Martian lithosphere in the vicinity of the ridged plains

    SciTech Connect

    Zuber, M.T. ); Aist, L.L. )

    1990-08-30

    Wrinkle ridges in the smooth plains of the Coprates and Lunae Planum regions of Mars form linear or concentric patterns with a regular spacing of 25-50 km. The authors test the hypothesis that the periodic development of deformation was a consequence of unstable horizontal compression, that occurred prior to probable ridge-related faulting, of a strength-stratified lithosphere which consists of a mechanically strong surface plains unit that successively overlies a weak megaregolith and a strong lithospheric basement. Results show that a range of models with both rigid and deformable megaregolith-basement interface conditions yield solutions which can explain the ridge spacing within the constraint provided by the estimated thickness of the smooth plains materials. In models that incorporate viscous and plastic rheologies, uniform and exponentially varying vertical strength distributions, and the presence or absence of interfacial slip at the base of the surface plains unit, the ridge spacing is primarily controlled by the power law exponent of the lithosphere, the megaregolith/plains unit thickness ratio, and the plains unit/megaregolith strength contrast. Deformable basement models with a viscous rheology (1 {le} n {approx}{le} 3) can explain the ridge spacing if the megaregolith was thicker than and approximately 1-3 orders of magnitude weaker than the plains unit. Similar models with a perfectly plastic (n {yields} {infinity}) rheology require plains unit thicknesses greater than 5 km, which exceeds most observational estimates. Ridge spacing in the combined viscous and plastic models can be consistent with either a dry, water-rich, or ice-rich megaregolith at the time of ridge formation.

  12. Segmentation of mid-ocean ridges attributed to oblique mantle divergence

    NASA Astrophysics Data System (ADS)

    Vanderbeek, Brandon P.; Toomey, Douglas R.; Hooft, Emilie E. E.; Wilcock, William S. D.

    2016-08-01

    The origin of mid-ocean ridge segmentation--the systematic along-axis variation in tectonic and magmatic processes--remains controversial. It is commonly assumed that mantle flow is a passive response to plate divergence and that between transform faults magma supply controls segmentation. Using seismic tomography, we constrain the geometry of mantle flow and the distribution of mantle melt beneath the intermediate-spreading Endeavour segment of the Juan de Fuca Ridge. Our results, in combination with prior studies, establish a systematic skew between the mantle-divergence and plate-spreading directions. In all three cases studied, mantle divergence is advanced with respect to recent changes in the plate-spreading direction and the extent to which the flow field is advanced increases with decreasing spreading rate. Furthermore, seismic images show that large-offset, non-transform discontinuities are regions of enhanced mantle melt retention. We propose that oblique mantle flow beneath mid-ocean ridges is a driving force for the reorientation of spreading segments and the formation of ridge-axis discontinuities. The resulting tectonic discontinuities decrease the efficiency of upward melt transport, thus defining segment-scale variations in magmatic processes. We predict that across spreading rates mid-ocean ridge segmentation is controlled by evolving patterns in asthenospheric flow and the dynamics of lithospheric rifting.

  13. Magma plumbing system and seismicity of an active mid-ocean ridge volcano.

    PubMed

    Schmid, Florian; Schlindwein, Vera; Koulakov, Ivan; Plötz, Aline; Scholz, John-Robert

    2017-02-20

    At mid-ocean ridges volcanism generally decreases with spreading rate but surprisingly massive volcanic centres occur at the slowest spreading ridges. These volcanoes can host unexpectedly strong earthquakes and vigorous, explosive submarine eruptions. Our understanding of the geodynamic processes forming these volcanic centres is still incomplete due to a lack of geophysical data and the difficulty to capture their rare phases of magmatic activity. We present a local earthquake tomographic image of the magma plumbing system beneath the Segment 8 volcano at the ultraslow-spreading Southwest Indian Ridge. The tomography shows a confined domain of partial melt under the volcano. We infer that from there melt is horizontally transported to a neighbouring ridge segment at 35 km distance where microearthquake swarms and intrusion tremor occur that suggest ongoing magmatic activity. Teleseismic earthquakes around the Segment 8 volcano, prior to our study, indicate that the current magmatic spreading episode may already have lasted over a decade and hence its temporal extent greatly exceeds the frequent short-lived spreading episodes at faster opening mid-ocean ridges.

  14. Magma plumbing system and seismicity of an active mid-ocean ridge volcano

    NASA Astrophysics Data System (ADS)

    Schmid, Florian; Schlindwein, Vera; Koulakov, Ivan; Plötz, Aline; Scholz, John-Robert

    2017-02-01

    At mid-ocean ridges volcanism generally decreases with spreading rate but surprisingly massive volcanic centres occur at the slowest spreading ridges. These volcanoes can host unexpectedly strong earthquakes and vigorous, explosive submarine eruptions. Our understanding of the geodynamic processes forming these volcanic centres is still incomplete due to a lack of geophysical data and the difficulty to capture their rare phases of magmatic activity. We present a local earthquake tomographic image of the magma plumbing system beneath the Segment 8 volcano at the ultraslow-spreading Southwest Indian Ridge. The tomography shows a confined domain of partial melt under the volcano. We infer that from there melt is horizontally transported to a neighbouring ridge segment at 35 km distance where microearthquake swarms and intrusion tremor occur that suggest ongoing magmatic activity. Teleseismic earthquakes around the Segment 8 volcano, prior to our study, indicate that the current magmatic spreading episode may already have lasted over a decade and hence its temporal extent greatly exceeds the frequent short-lived spreading episodes at faster opening mid-ocean ridges.

  15. Magma plumbing system and seismicity of an active mid-ocean ridge volcano

    PubMed Central

    Schmid, Florian; Schlindwein, Vera; Koulakov, Ivan; Plötz, Aline; Scholz, John-Robert

    2017-01-01

    At mid-ocean ridges volcanism generally decreases with spreading rate but surprisingly massive volcanic centres occur at the slowest spreading ridges. These volcanoes can host unexpectedly strong earthquakes and vigorous, explosive submarine eruptions. Our understanding of the geodynamic processes forming these volcanic centres is still incomplete due to a lack of geophysical data and the difficulty to capture their rare phases of magmatic activity. We present a local earthquake tomographic image of the magma plumbing system beneath the Segment 8 volcano at the ultraslow-spreading Southwest Indian Ridge. The tomography shows a confined domain of partial melt under the volcano. We infer that from there melt is horizontally transported to a neighbouring ridge segment at 35 km distance where microearthquake swarms and intrusion tremor occur that suggest ongoing magmatic activity. Teleseismic earthquakes around the Segment 8 volcano, prior to our study, indicate that the current magmatic spreading episode may already have lasted over a decade and hence its temporal extent greatly exceeds the frequent short-lived spreading episodes at faster opening mid-ocean ridges. PMID:28218270

  16. Underlying fracture zone nature of Astrid Ridge off Antarctica's Queen Maud Land

    NASA Astrophysics Data System (ADS)

    Bergh, Hugh W.

    1987-01-01

    New geophysical data are used to refine the extent and setting of Astrid Ridge, a volcanic edifice lying off the Princess Astrid Coast section (5°E to 20°E) of Queen Maud Land in Antarctica. New findings presented here include a well-defined fracture zone, occurring as a narrow basement ridge which extends northeast from Astrid Ridge, and an adjacent set of Mesozoic magnetic anomalies M0 to M9, which are offset by 120 km from an identical, previously described set. These two sets of anomalies are combined with the conjugate Mozambique Basin anomalies to define an Africa-Antarctica rotation pole at 10°S, 29°W for anomaly M2 time. The northern edge of Astrid Ridge and the sharp southern margin of the Mozambique Ridge on the African plate are probably related to the same cessation of excess volcanic activity near the end of the Cretaceous normal polarity interval. Both features had their eastern and western limits confined by a contiguous pair of fracture zones. A possible major swing in fracture zone trend prior to anomaly M9 is also suggested.

  17. West Chestnut Ridge hydrologic studies

    SciTech Connect

    Elmore, J.L.; Huff, D.D.; Jones, J.R.

    1985-08-01

    Preliminary site characterization work for the proposed West Chestnut Ridge Central Waste Disposal Facility included collection and analysis of data on stream flows, watershed areas, precipitation, water levels at piezometer sites, and physiochemical properties of surface water. Seven temporary water-flow-gaging installations were established and used to characterize runoff patterns in the study area. Chip-floating and regression techniques were used to estimate stream flows after some of the temporary structures were destroyed during high flows. Stream flow fluctuations were quantified using coefficients of variation and percent change in total flow between adjacent sampling dates. The difference between precipitation and observed flows (net loss) was calculated for all stations. Two headwater stations (4 and 6) exhibited lower flows per watershed area and channel length, and higher levels of fluctuation in flow than the other stations. These two stations were also similar in watershed area and flow magnitude. Two other headwater stations (5 and 7) with comparable flows had total drainage areas that were similar in size and smaller than those of the other stations. Stations 5 and 7 exhibited high flows per drainage area and section length, especially in the dry period of the year when flows were higher than at all other stations. Fluctuations in flows were lowest at these two stations. Data indicate that these two sections are fed by sources of dependable groundwater. 7 refs., 4 figs., 8 tabs.

  18. Low Sun from 'Low Ridge'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    A spectacular field of Martian sand ripples separates NASA's Mars Exploration Rover Spirit from the slopes of 'Husband Hill.' It has been 200 Martian days, or sols, since the rover started a descent from the top of the peak to the rover's current position on 'Low Ridge.' Looking back to the north on sol 813 (April 17, 2006), Spirit acquired this blue-filter (436-nanometer) view with the right panoramic camera (Pancam) while the Sun was low in the sky late in the afternoon. Because of the low-angle lighting (sunlight is coming from the left), images like this provide superb views of subtle textures in the topography both near and far. Husband Hill, where the rover was perched late last summer, rises prominently just left of center in this view. A 150-meter wide (500 foot) field of curving sand ripples named 'El Dorado' lies at the base of Husband Hill.

    By collecting photos like this at different times of day, when lighting comes from different directions, scientists can distinguish surface properties such as color and reflectivity from topography and roughness. By separating these components they can map more details of the geologic terrain, providing new clues about the geologic history of Gusev Crater.

  19. Prior Distributions on Symmetric Groups

    ERIC Educational Resources Information Center

    Gupta, Jayanti; Damien, Paul

    2005-01-01

    Fully and partially ranked data arise in a variety of contexts. From a Bayesian perspective, attention has focused on distance-based models; in particular, the Mallows model and extensions thereof. In this paper, a class of prior distributions, the "Binary Tree," is developed on the symmetric group. The attractive features of the class are: it…

  20. Physical priors in virtual colonoscopy

    NASA Astrophysics Data System (ADS)

    Rivaz, Hassan; Shinagawa, Yoshihisa; Liang, Jianming

    2009-02-01

    Electronic colon cleansing (ECC) aims to remove the contrast agent from the CT abdominal images so that a virtual model of the colon can be constructed. Virtual colonoscopy requires either liquid or solid preparation of the colon before CT imaging. This paper has two parts to address ECC in both preparation methods. In the first part, meniscus removal in the liquid preparation is studied. The meniscus is the curve seen at the top of a liquid in response to its container. Left on the colon wall, the meniscus can decrease the sensitivity and specificity of virtual colonoscopy. We state the differential equation that governs the profile of the meniscus and propose an algorithm for calculating the boundary of the contrast agent. We compute the surface tension of the liquid-colon wall contact using in-vivo CT data. Our results show that the surface tension can be estimated with an acceptable degree of uncertainty. Such an estimate, along with the meniscus profile differential equation will be used as an a priori knowledge to aid meniscus segmentation. In the second part, we study ECC in solid preparation of colon. Since the colon is pressurized with air before acquisition of the CT images, a prior on the shape of the colon wall can be obtained. We present such prior and investigate it using patient data. We show the shape prior is held in certain parts of the colon and propose a method that uses this prior to ease pseudoenhancement correction.

  1. Carlsberg Ridge and Mid-Atlantic Ridge: Comparison of slow spreading centre analogues

    NASA Astrophysics Data System (ADS)

    Murton, Bramley J.; Rona, Peter A.

    2015-11-01

    Eighty per cent of all mid-ocean spreading centres are slow. Using a mixture of global bathymetry data and ship-board multibeam echosounder data, we explore the morphology of global mid-ocean ridges and compare two slow spreading analogues: the Carlsberg Ridge in the north-west Indian Ocean between 57°E and 60°E, and the Kane to Atlantis super-segment of the Mid-Atlantic Ridge between 21°N and 31°N. At a global scale, mid-ocean spreading centres show an inverse correlation between segment length and spreading rate with segmentation frequency. Within this context, both the Mid-Atlantic Ridge super-segment and Carlsberg Ridge are similar: spreading at 22 and 26 mm/yr full rates respectively, being devoid of major transform faults, and being segmented by dextral, non-transform, second-order discontinuities. For these and other slow spreading ridges, we show that segmentation frequency varies inversely with flank height and ridge axis depth. Segments on both the Mid-Atlantic Ridge super-segment and Carlsberg Ridge range in aspect ratio (ridge flank height/axis width), depth and symmetry. Segments with high aspect ratios and deeper axial floors often have asymmetric rift flanks and are associated with indicators of lower degrees of melt flux. Segments with low aspect ratios have shallower axial floors, symmetric rift flanks, and evidence of robust melt supply. The relationship between segmentation, spreading rate, ridge depth and morphology, at both a global and local scale, is evidence that rates of melting of the underlying mantle and melt delivery to the crust play a significant role in determining the structure and morphology of slow spreading mid-ocean ridges.

  2. 27 CFR 9.182 - Ribbon Ridge.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., Oregon, 1956, revised 1993. (c) Boundary. The Ribbon Ridge viticultural area is located in northern... Quadrangle map at the intersection of a light-duty road known locally as Albertson Road and Dopp Road...

  3. 27 CFR 9.182 - Ribbon Ridge.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., Oregon, 1956, revised 1993. (c) Boundary. The Ribbon Ridge viticultural area is located in northern... Quadrangle map at the intersection of a light-duty road known locally as Albertson Road and Dopp Road...

  4. 27 CFR 9.182 - Ribbon Ridge.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., Oregon, 1956, revised 1993. (c) Boundary. The Ribbon Ridge viticultural area is located in northern... Quadrangle map at the intersection of a light-duty road known locally as Albertson Road and Dopp Road...

  5. 27 CFR 9.182 - Ribbon Ridge.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., Oregon, 1956, revised 1993. (c) Boundary. The Ribbon Ridge viticultural area is located in northern... Quadrangle map at the intersection of a light-duty road known locally as Albertson Road and Dopp Road...

  6. 27 CFR 9.182 - Ribbon Ridge.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., Oregon, 1956, revised 1993. (c) Boundary. The Ribbon Ridge viticultural area is located in northern... Quadrangle map at the intersection of a light-duty road known locally as Albertson Road and Dopp Road...

  7. Oak Ridge Reservation annual site environmental report for 1996

    SciTech Connect

    1997-10-01

    The US Department of Energy currently oversees activities on the Oak Ridge Reservation (ORR), a government-owned, contractor-operated facility. Three sites compose the reservation: the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory, and East Tennessee Technology Park (formerly the K-25 Site). The ORR was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced the materials for the first atomic bombs. The reservation`s role has evolved over the years, and it continues to adapt to meet the changing defense, energy, and research needs of the US. Both the work carried out for the war effort and subsequent research, development, and production activities have produced (and continue to produce) radiological and hazardous wastes. This document contains a summary of environmental monitoring activities on the ORR and its surroundings. Environmental monitoring on the ORR consists of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring involves the collection and analysis of samples or measurements of liquid and gaseous effluents prior to release into the environment; these measurements allow the quantification and official reporting of contaminants, assessment of radiation exposures to the public, and demonstration of compliance with applicable standards and permit requirements. Environmental surveillance consists of the collection and analysis of environmental samples from the site and its environs; this provides direct measurement of contaminants in air, water, groundwater, soil, foods, biota, and other media subsequent to effluent release into the environment. Environmental surveillance data verify ORR`s compliance status and, combined with data from effluent monitoring, allow the determination of chemical and radiation dose/exposure assessment of ORR operations and effects, if any, on the local environment.

  8. A coral-rubble ridge as evidence for hurricane overwash, Anegada (British Virgin Islands)

    NASA Astrophysics Data System (ADS)

    Spiske, M.; Halley, R. B.

    2014-01-01

    A coral-rubble ridge fringes part of the north shore of Anegada, a low-lying island in the northern Caribbean. Both historical reports and the geological record underline its vulnerability to tsunami and hurricanes. In this study we document the sedimentary characteristics of a coral-rubble ridge, which extends discontinuously along 1.5-1.8 km of chiefly north-facing shores at Soldier Wash. The ridge is less distinctive and appears only in patches along the west-facing shoreline at Windless Bight, where the wave regime is calmer. It is located ca. 8 m from the fair-weather shore, has a maximum width of 15 m and a maximum thickness of 0.8 m. The lower seaward-facing slope of the ridge is relatively flat, probably due to successive reworking, whereas the upper seaward slope is steep and partly displays avalanching faces. The landward flank is gently sloping and terminates abruptly. The ridge is mainly composed of well-rounded, encrusted and bored coral rubble (average diameter of 16 cm) that has been reworked in the shallow marine environment prior to transport. Only a few pieces of angular beach rock and karstified Pleistocene limestone are incorporated. The components build a clast-supported framework. No sand is present in the interstices. Imbrication of flat clasts indicates a deposition during landward bed load transport. The ridge morphology, composition and related hydrodynamic conditions during its emplacement are typical for coral-rubble ridges deposited by hurricane-induced storm surges. In comparison, nearby evidence for tsunami inundation is very different because the tsunami-transported coral boulders on Anegada are much bigger (2 m) than the biggest components in the ridge, they are deposited much farther inland (up to 1.5 km), and the corals seem to have been freshly broken out of the reef by the tsunami. The age of the ridge is difficult to estimate. The dark grey surface of the ridge is caused by bioweathering by endolithic organisms that takes tens

  9. Dark and Bright Ridges on Europa

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This high-resolution image of Jupiter's moon Europa, taken by NASA's Galileo spacecraft camera, shows dark, relatively smooth region at the lower right hand corner of the image which may be a place where warm ice has welled up from below. The region is approximately 30 square kilometers in area. An isolated bright hill stands within it. The image also shows two prominent ridges which have different characteristics; youngest ridge runs from left to top right and is about 5 kilometers in width (about 3.1 miles). The ridge has two bright, raised rims and a central valley. The rims of the ridge are rough in texture. The inner and outer walls show bright and dark debris streaming downslope, some of it forming broad fans. This ridge overlies and therefore must be younger than a second ridge running from top to bottom on the left side of the image. This dark 2 km wide ridge is relatively flat, and has smaller-scale ridges and troughs along its length.

    North is to the top of the picture, and the sun illuminates the surface from the upper left. This image, centered at approximately 14 degrees south latitude and 194 degrees west longitude, covers an area approximately 15 kilometers by 20 kilometers (9 miles by 12 miles). The resolution is 26 meters (85 feet) per picture element. This image was taken on December 16, 1997 at a range of 1300 kilometers (800 miles) by Galileo's solid state imaging system.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  10. Internal Tide Generation by Tall Ocean Ridges

    DTIC Science & Technology

    2009-09-01

    April 26th, 1996, of the area enclosed by the solid line in the map of the South China Sea (right). The dashed line indicates the location of the Luzon...115 15 4-9 Bathymetry of (a) the ridge at French Frigate Shoals (FFS) and (b) the Keana Ridge (KR) in the Kauai Channel. The...The thick lines in panel (b) indicate the raw bathymetry data (solid) and a smoothed version of the profile (dashed), and the inset presents the local

  11. Soil Management Plan for the Oak Ridge Y-12 National Security Complex Oak Ridge, Tennessee

    SciTech Connect

    2005-03-02

    This Soil Management Plan applies to all activities conducted under the auspices of the National Nuclear Security Administration (NNSA) Oak Ridge Y-12 National Security Complex (Y-12) that involve soil disturbance and potential management of waste soil. The plan was prepared under the direction of the Y-12 Environmental Compliance Department of the Environment, Safety, and Health Division. Soil disturbances related to maintenance activities, utility and building construction projects, or demolition projects fall within the purview of the plan. This Soil Management Plan represents an integrated, visually oriented, planning and information resource tool for decision making involving excavation or disturbance of soil at Y-12. This Soil Management Plan addresses three primary elements. (1) Regulatory and programmatic requirements for management of soil based on the location of a soil disturbance project and/or the regulatory classification of any contaminants that may be present (Chap. 2). Five general regulatory or programmatic classifications of soil are recognized to be potentially present at Y-12; soil may fall under one or more these classifications: (a) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) pursuant to the Oak Ridge Reservation (ORR) Federal Facilities Agreement; (b) Resource Conservation and Recovery Act (RCRA); (c) RCRA 3004(u) solid waste managements units pursuant to the RCRA Hazardous and Solid Waste Amendments Act of 1984 permit for the ORR; (d) Toxic Substances and Control Act-regulated soil containing polychlorinated biphenyls; and (e) Radiologically contaminated soil regulated under the Atomic Energy Act review process. (2) Information for project planners on current and future planned remedial actions (RAs), as prescribed by CERCLA decision documents (including the scope of the actions and remedial goals), land use controls implemented to support or maintain RAs, RCRA post-closure regulatory requirements for

  12. Assessing the clarity of friction ridge impressions.

    PubMed

    Hicklin, R Austin; Buscaglia, JoAnn; Roberts, Maria Antonia

    2013-03-10

    The ability of friction ridge examiners to correctly discern and make use of the ridges and associated features in finger or palm impressions is limited by clarity. The clarity of an impression relates to the examiner's confidence that the presence, absence, and attributes of features can be correctly discerned. Despite the importance of clarity in the examination process, there have not previously been standard methods for assessing clarity in friction ridge impressions. We introduce a process for annotation, analysis, and interchange of friction ridge clarity information that can be applied to latent or exemplar impressions. This paper: (1) describes a method for evaluating the clarity of friction ridge impressions by using color-coded annotations that can be used by examiners or automated systems; (2) discusses algorithms for overall clarity metrics based on manual or automated clarity annotation; and (3) defines a method of quantifying the correspondence of clarity when comparing a pair of friction ridge images, based on clarity annotation and resulting metrics. Different uses of this approach include examiner interchange of data, quality assurance, metrics, and as an aid in automated fingerprint matching.

  13. Hydrothermal activity on the Gorda Ridge

    NASA Astrophysics Data System (ADS)

    Rona, Peter A.

    Near-bottom plumes of materials indicative of discharge of metal-rich hot springs were discovered at sites on the Gorda Ridge by a research team of government and university scientists on a cruise of the National Oceanic and Atmospheric Administration (NOAA) ship Surveyor during May 1985 as part of the NOAA Vents Program. The Gorda Ridge, off northern California and Oregon, is the only seafloor spreading center within the proclaimed 200-mile U.S. Exclusive Economic Zone (370 km wide) of the conterminous United States and is one of the last oceanic ridges to be explored for metal-rich hot springs. One reason for this neglect is that the Gorda Ridge is slow spreading, with half-rates ranging from 1.1 cm/yr in the southern portion to 2.2 cm/yr in the northern portion. Slow spreading centers have not been fully evaluated with regard to hydrothermal activity by many members of the research community, who have concentrated their attention on the faster spreading East Pacific Rise to the south and the Juan de Fuca Ridge to the north of the Gorda Ridge.

  14. Oak Ridge Reservation environmental report for 1989

    SciTech Connect

    Jacobs, V.A.; Wilson, A.R.

    1990-10-01

    This two-volume report, the Oak Ridge Reservation Environmental Report for 1989, is the nineteenth in an annual series that began in 1971. It reports the results of a comprehensive, year-round program to monitor the impact of operations at the three major US Department of Energy (DOE) production and research installations in Oak Ridge on the immediate areas' and surrounding region's groundwater and surface waters, soil, air quality, vegetation and wildlife, and through these multiple and varied pathways, the resident human population. Information is presented for the environmental monitoring Quality Assurance (QA) Program, audits and reviews, waste management activities, land special environmental studies. Data are included for the Oak Ridge Y-12 Plant, Oak Ridge National Laboratory (ORNL), and Oak Ridge Gaseous Diffusion Plant (ORGDP). Volume 1 presents narratives, summaries, and conclusions based on environmental monitoring at the three DOE installations and in the surrounding environs during calendar year (CY) 1989. Volume 1 is intended to be a stand-alone'' report about the Oak Ridge Reservation (ORR) for the reader who does not want an in-depth review of 1989 data. Volume 2 presents the detailed data from which these conclusions have been drawn and should be used in conjunction with Volume 1.

  15. Rare-earth occurrences in the Pea Ridge tailings

    SciTech Connect

    Vierrether, C.W.; Cornell, W.I.

    1993-01-01

    Tailings from the Pea Ridge iron mine contain significant amounts of apatite, which has rare-earth element values associated with it. In association with the recovery of rare-earth minerals as a secondary resource, the US Bureau of Mines conducted an investigation on the recoverability of the rare-earth minerals from the tailings. The mill tailings were subjected to a phosphate flotation to separate the apatite from other constituents. More than 70-pct recovery of the rare-earth values was achieved. Based on mineralogical characterization and prior analysis of rare-earth-bearing breccia pipe material at Pea Ridge, it is proposed that processing this phosphate concentrate on a vanner table would yield up to a 95-pct recovery of the rare earths in the concentrate, with the apatite reporting to the tailings. Intensive ore microscopy studies of the original tailings to the flotation products led to the identification of monazite, xenotime, and rare-earth-enriched apatite as the major rare-earth-bearing minerals in the tailings.

  16. 77 FR 68818 - Notice of Inventory Completion: U.S. Department of Energy Oak Ridge Office, Oak Ridge, TN

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-16

    ... National Park Service Notice of Inventory Completion: U.S. Department of Energy Oak Ridge Office, Oak Ridge... Oak Ridge Office has completed an inventory of human remains and associated funerary object, in... associated funerary object may contact the U.S. Department of Energy Oak Ridge Office. Repatriation of...

  17. 78 FR 2431 - Notice of Inventory Completion: U.S. Department of Energy Oak Ridge Office, Oak Ridge, TN...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-11

    ... National Park Service Notice of Inventory Completion: U.S. Department of Energy Oak Ridge Office, Oak Ridge.... Department of Energy Oak Ridge Office has corrected an inventory of human remains and associated funerary... of Energy Oak Ridge Office. Repatriation of the human remains and associated funerary object to...

  18. Postremediation monitoring program baseline assessment report, Lower East Fork Poplar Creek, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    Greeley, M.S. Jr.; Ashwood, T.L.; Kszos, L.A.; Peterson, M.J.; Rash, C.D.; Southworth, G.R.; Phipps, T.L.

    1998-04-01

    Lower East Fork Poplar Creek (LEFPC) and its floodplain are contaminated with mercury (Hg) from ongoing and historical releases from the US Department of Energy (DOE) Oak Ridge Y-12 Plant. A remedial investigation and feasibility study of LEFPC resulted in the signing of a Record of Decision (ROD) in August 1995. In response to the ROD, soil contaminated with mercury above 400 mg/kg was removed from two sites in LEFPC and the floodplain during a recently completed remedial action (RA). The Postremediation Monitoring Program (PMP) outlined in the LEFPC Monitoring Plan was envisioned to occur in two phases: (1) a baseline assessment prior to remediation and (2) postremediation monitoring. The current report summarizes the results of the baseline assessment of soil, water, biota, and groundwater usage in LEFPC and its floodplain conducted in 1995 and 1996 by personnel of the Oak Ridge National Laboratory Biological Monitoring and Abatement Program (BMAP). This report also includes some 1997 data from contaminated sites that did not undergo remediation during the RA (i.e., sites where mercury is greater than 200 mg/kg but less than 400 mg/kg). The baseline assessment described in this document is distinct and separate from both the remedial investigation/feasibility study the confirmatory sampling conducted by SAIC during the RA. The purpose of the current assessment was to provide preremediation baseline data for the LEFPC PMP outlined in the LEFPC Monitoring Plan, using common approaches and techniques, as specified in that plan.

  19. Spreading Dynamics of an Intermediate Ridge: Endeavour Segment of the Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Scott, S. R.; Ramos, F. C.; Gill, J. B.

    2011-12-01

    U/Th disequilibria analyses of 36 on- and off-axis MORB samples from the Endeavour segment of the Juan de Fuca Ridge, an intermediate spreading ridge off the Pacific Northwest coast of the USA, reflect recent spreading and time-integrated geochemical variability. Previous major and trace element and isotopic data from Endeavour samples exhibit a wide range of geochemical characteristics for samples within close spatial proximity, including EMORB, TMORB and NMORB. Morphology of Endeavour constrains lavas erupted on-axis to flow within the current axial valley, preventing axial lavas from flowing off-axis. This relationship can be used to date any MORB found outside of the axial valley, assuming all types lie on a single zero-age line from the most depleted to most enriched lavas. U-Th data indicate that all EMORB and the majority of TMORB are zero-age (<10 ka) within error and lie on a single zero-age line. EMORB with equivalent (within error) young ages on both sides of the axial valley and that span across the entire eastern flank of the ridge erupted prior to the formation of the current axial valley and within a short time interval (<10 ky). If the axial valley formed within the last 10 ky, the minimum full spreading rate falls around 8 cm/yr. If the majority of EMORB are <8 ka, the axial valley may have formed at a full spreading rate of 10 cm/yr or greater. These U-Th age constraints on EMORB yield a spreading rate faster than the time-integrated spreading rate (5 cm/yr). An EMORB sample located furthest east of the axis is at least 70 ky younger than expected based on the time-integrated spreading rate (5 cm/yr). One on-axis TMORB is not within error of the E-T zero-age line, and may be as old as 17 ka. U-Th ages of TMORB from the western flank fall between 25 and ~100 ka, older than all EMORB. NMORB generally have higher Th isotope ratios than E- or TMORB for a given U/Th ratio and lie on a second zero-age line. One NMORB, on the far western flank, is ~40 ky

  20. Formation and stability of ridge-ridge-ridge triple junctions in rheologically realistic lithosphere model

    NASA Astrophysics Data System (ADS)

    Gerya, Taras; Burov, Evgueni

    2015-04-01

    -branch junction formation and evolution by using high-resolution 3D numerical mechanical experiments that take into account realistic thermo-rheological structure and rheology of the lithosphere. We find that two major types of quadruple and triple junctions are formed under bi-directional or multidirectional far-field stress field: (i) plate rifting junctions are formed by the initial plate fragmentation and can be subsequently re-arranged into (ii) oceanic spreading junctions controlled by the new oceanic crust accretion. In particular, we document initial formation and destabilization of quadruple R-R-R-R junctions as initial plate rifting structures under bi-directional extension. In most cases, quadruple plate rifting junctions rapidly (typically within 1-2 Myr) evolve towards formation of two diverging triple oceanic spreading junctions connected by a linear spreading center lengthening with time. This configuration remains stable over long time scales. However, under certain conditions, quadruple junctions may also remain relatively stable. Asymmetric stretching results in various configurations, for example formation of "T-junctions" with trans-extensional components and combination of fast and slow spreading ridges. Combined with plume impingement, this scenario evolves in realistic patterns closely resembling observed plate dynamics. In particular, opening of the Red Sea and of the Afar rift system find a logical explanation within a single model. Numerical experiments also suggest that several existing oceanic spreading junctions form as the result of plate motions rearrangements after which only one of two plates spreading along the ridge become subjected to bi-directional spreading.

  1. Remedial Investigation Work Plan for Chestnut Ridge Operable Unit 1 (Chestnut Ridge Security Pits) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1994-03-01

    This document outlines the activities necessary to conduct a Remedial Investigation (RI) of the Chestnut Ridge Security Pits (CRSP) at the Oak Ridge Y-12 Plant. The CRSP, also designated Chestnut Ridge Operable Unit (OU) 1, is one of four OUs along Chestnut Ridge on the Oak Ridge Reservation (ORR). The purpose of the RI is to collect data to (1) evaluate the nature and extent of known and suspected contaminants, (2) support an Ecological Risk Assessment (ERA) and a Human Health Risk Assessment (HHRA), (3) support the feasibility study in the development and analysis of remedial alternatives, and (4) ultimately, develop a Record of Decision (ROD) for the site. This chapter summarizes the regulatory background of environmental investigation on the ORR and the approach currently being followed and provides an overview of the RI to be conducted at the CRSP. Subsequent chapters provide details on site history, sampling activities, procedures and methods, quality assurance (QA), health and safety, and waste management related to the RI.

  2. Cell migration on ridges and cliffs

    NASA Astrophysics Data System (ADS)

    Driscoll, Meghan; McCann, Colin; Kopace, Rael; Watts, John; Homan, Tess; Losert, Wolfgang

    2009-03-01

    The amoeba Dictyostelium discoideum is a model system for the study of cellular migration, an important physiological process that occurs in embryonic development, wound healing, and cancer metastasis. We study the motion of D. discoideum on surfaces with various topographies, particularly those that affect the direction of cellular migration. Topographical features, such as ridges and cliffs, were fabricated using multiphoton absorption polymerization. As the cells encountered these topographical features, we tracked their overall motions and shapes, as well as the locations and intensities of certain intracellular signals. We found that when cells undergoing chemokinesis, random migration in response to a chemical signal, encounter a ridge, they tend to move along that ridge, even if the ridge is shorter than the cell. When cells undergoing chemotaxis, directed migration in response to a chemical signal, are directed off of a cliff, they do not fall off the cliff. Instead, they search for new attachment points, eventually change direction, and continue moving along the edge of the cliff. Both ridges and cliffs affect more than just the motion of a cell; they also affect its shape.

  3. Vertical Alveolar Ridge Augmentation by Distraction Osteogenesis

    PubMed Central

    Kumar, N. Nanda; Ravindran, C.

    2015-01-01

    Introduction Compromised alveolar ridge in vertical and horizontal dimension is a common finding in patients visiting practitioners for dental prosthesis. Various treatment modalities are available for correction of deficient ridges among which alveolar distraction osteogenesis is one. Aim To study the efficacy of alveolar distraction osteogenesis in augmentation of alveolar ridges deficient in vertical dimension. Materials and Methods Ten patients aged 16 to 46 years with deficient alveolar ridge underwent ridge augmentation in 11 alveolar segments using the distraction osteogenesis method. For each patient a custom made distraction device was fabricated. The device was indigenously manufactured with SS-316 (ISO 3506). Results The vertical bone gain reached more than 10mm without the use of bone transplantation. Certain complications like incorrect vector of distraction, paresthesia, pain and loss of transport segment were encountered during the course of the study. Conclusion Alveolar vertical distraction osteogenesis is a reliable and predictable technique for both hard and soft tissue genesis. Implant placement is feasible with primary stability in neogenerated bone at the level of the distracted areas. PMID:26816991

  4. Arctic Ocean: hydrothermal activity on Gakkel Ridge.

    PubMed

    Jean-Baptiste, Philippe; Fourré, Elise

    2004-03-04

    In the hydrothermal circulation at mid-ocean ridges, sea water penetrates the fractured crust, becomes heated by its proximity to the hot magma, and returns to the sea floor as hot fluids enriched in various chemical elements. In contradiction to earlier results that predict diminishing hydrothermal activity with decreasing spreading rate, a survey of the ultra-slowly spreading Gakkel Ridge (Arctic Ocean) by Edmonds et al. and Michael et al. suggests that, instead of being rare, the hydrothermal activity is abundant--exceeding by at least a factor of two to three what would be expected by extrapolation from observation on faster spreading ridges. Here we use helium-3 (3He), a hydrothermal tracer, to show that this abundance of venting sites does not translate, as would be expected, into an anomalous hydrothermal 3He output from the ridge. Because of the wide implications of the submarine hydrothermal processes for mantle heat and mass fluxes to the ocean, these conflicting results call for clarification of the link between hydrothermal activity and crustal production at mid-ocean ridges.

  5. Cancer mortality near Oak Ridge, Tennessee.

    PubMed

    Mangano, J J

    1994-01-01

    Oak Ridge, Tennessee, is the site of one of the two oldest nuclear facilities in the United States. Although precise records have not been maintained, low levels of radioactive products have been released into the environment since the facility began operation in World War II. Changes in age-adjusted cancer mortality rates for whites between the periods 1950-1952 and 1987-1989 were analyzed to assess whether these radioactive releases have had any adverse effects on the population living near Oak Ridge. Results indicate that the increases in the local area (under 100 miles from Oak Ridge) exceeded regional increases and far exceeded national increases. Within the region, increases were greatest in rural areas, in Anderson County (where Oak Ridge is located), in mountainous counties, and in the region downwind of Oak Ridge. Each of these findings suggest that low levels of radiation, ingested gradually by local residents, were a factor in the increases in local cancer death rates. Results indicate that more studies of this type are called for and that cessation of all future radioactive emissions from nuclear facilities should be considered.

  6. Global Characterization of the Ocean Ridge System

    NASA Astrophysics Data System (ADS)

    Gale, A.; Langmuir, C. H.; Dalton, C. A.

    2010-12-01

    The mid-ocean ridge system is a window into the upper mantle, producing over 80% of Earth’s volcanism. Fundamental, first-order questions remain debated and require a reliable global perspective. Such questions include the relative roles of mantle temperature, mantle heterogeneity and spreading rate on mid-ocean ridge basalt (MORB) compositions, and the importance of spreading rate to melting and fractionation processes. To address these issues and provide a common reference for geochemists and geophysicists, we have assembled a comprehensive petrological presentation of global MORB. The data are compiled from PetDB as well as unpublished data. Transforming the raw data into a useful catalog poses several challenges. First, to link each sample with a particular ridge segment requires defining the individual segments of the ridge system. Using the highest resolution bathymetry available, we identified 771 global ridge segments with a total length of 60,864km. For each segment we also generated a digital along-strike depth profile, enabling precise characterization of both mean depth and depth range. Second, as noted in earlier work, different laboratories calibrate their analyses to different standards, which can lead to significant, systematic offsets among analyses. It is therefore important to apply correction factors to the data to make them consistent with one another. Erroneous data and mislocated samples were identified and either eliminated or manually corrected, leading to a total dataset of 11,366 glass and 874 whole-rock analyses that have had interlab correction values carefully applied. These results show that the mean depth of the global ridge system is 2981m, calculated by averaging the segment mean depths, weighted by segment length. Of the 771 ridge segments, 476 have at least one basalt sample within 10km of the ridge axis but only 181 segments have samples from three or more unique locations. Using these data, a far more reliable composition can

  7. ORLANDO -- Oak Ridge Large Neutrino Detector

    SciTech Connect

    Bugg, W.; Cohn, H.; Efremenko, Yu.; Gabriel, T.; Kamyshkov, Yu.; Plasil, F.; Fazely, A.; Svoboda, R.

    1997-12-01

    The authors discuss a proposal for construction of an Oak Ridge LArge Neutrino DetectOr (ORLANDO) to search for neutrino oscillations at the Spallation Neutron Source (SNS). A 4 MW SNS is proposed to be built at the Oak Ridge National Laboratory with the first stage to be operative around 2006. It will have two target stations, which makes it possible with a single detector to perform a neutrino oscillation search at two different distances. Initial plans for the placement of the detector and the discovery potential of such a detector are discussed.

  8. Marginal ridge fracture resistance, microleakage and pulpal response to glass ionomer/glass cermet partial tunnel restorations.

    PubMed

    Prabhu, N T; Munshi, A K; Shetty, T R

    1997-01-01

    Sixty sound premolars which were to be extracted for orthodontic treatment purposes were restored either with glass ionomer cement or glass cermet cements after partial tunnel preparation, and prior to the extraction after a time interval of 30 and 60 days respectively. The teeth were then subjected to marginal ridge fracture resistance, microleakage study using dye penetration and histological evaluation of the pulpal response to these materials. Both the materials exhibited increase in marginal ridge fracture resistance at 60 days, with minimal degree of microleakage and were biologically compatible with the dental pulp.

  9. Fluid venting and seepage at accretionary ridges: the Four Way Closure Ridge offshore SW Taiwan

    NASA Astrophysics Data System (ADS)

    Klaucke, Ingo; Berndt, Christian; Crutchley, Gareth; Chi, Wu-Cheng; Lin, Saulwood; Muff, Sina

    2016-06-01

    Within the accretionary prism offshore SW Taiwan, widespread gas hydrate accumulations are postulated to occur based on the presence of a bottom simulating reflection. Methane seepage, however, is also widespread at accretionary ridges offshore SW Taiwan and may indicate a significant loss of methane bypassing the gas hydrate system. Four Way Closure Ridge, located in 1,500 m water depth, is an anticlinal ridge that would constitute an ideal trap for methane and consequently represents a site with good potential for gas hydrate accumulations. The analysis of high-resolution bathymetry, deep-towed sidescan sonar imagery, high-resolution seismic profiling and towed video observations of the seafloor shows that Four Way Closure Ridge is and has been a site of intensive methane seepage. Continuous seepage is mainly evidenced by large accumulations of authigenic carbonate precipitates, which appear to be controlled by the creation of fluid pathways through faulting. Consequently, Four Way Closure Ridge is not a closed system in terms of fluid migration and seepage. A conceptual model of the evolution of gas hydrates and seepage at accretionary ridges suggests that seepage is common and may be a standard feature during the geological development of ridges in accretionary prisms. The observation of seafloor seepage alone is therefore not a reliable indicator of exploitable gas hydrate accumulations at depth.

  10. The influence of ridge migration on the magmatic segmentation of mid-ocean ridges.

    PubMed

    Carbotte, S M; Small, C; Donnelly, K

    2004-06-17

    The Earth's mid-ocean ridges display systematic changes in depth and shape, which subdivide the ridges into discrete spreading segments bounded by transform faults and smaller non-transform offsets of the axis. These morphological changes have been attributed to spatial variations in the supply of magma from the mantle, although the origin of the variations is poorly understood. Here we show that magmatic segmentation of ridges with fast and intermediate spreading rates is directly related to the migration velocity of the spreading axis over the mantle. For over 9,500 km of mid-ocean ridge examined, leading ridge segments in the 'hotspot' reference frame coincide with the shallow magmatically robust segments across 86 per cent of all transform faults and 73 per cent of all second-order discontinuities. We attribute this relationship to asymmetric mantle upwelling and melt production due to ridge migration, with focusing of melt towards ridge segments across discontinuities. The model is consistent with variations in crustal structure across discontinuities of the East Pacific Rise, and may explain variations in depth of melting and the distribution of enriched lavas.

  11. Wrinkle Ridges and Young Fresh Crater

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 10 May 2002) The Science Wrinkle ridges are a very common landform on Mars, Mercury, Venus, and the Moon. These ridges are linear to arcuate asymmetric topographic highs commonly found on smooth plains. The origin of wrinkle ridges is not certain and two leading hypotheses have been put forth by scientists over the past 40 years. The volcanic model calls for the extrusion of high viscosity lavas along linear conduits. This thick lava accumulated over these conduits and formed the ridges. The other model is tectonic and advocates that the ridges are formed by compressional faulting and folding. Today's THEMIS image is of the ridged plains of Lunae Planum located between Kasei Valles and Valles Marineris in the northern hemisphere of the planet. Wrinkle ridges are found mostly along the eastern side of the image. The broadest wrinkle ridges in this image are up to 2 km wide. A 3 km diameter young fresh crater is located near the bottom of the image. The crater's ejecta blanket is also clearly seen surrounding the sharp well-defined crater rim. These features are indicative of a very young crater that has not been subjected to erosional processes. The Story The great thing about the solar system is that planets are both alike and different. They're all foreign enough to be mysterious and intriguing, and yet familiar enough to be seen as planetary 'cousins.' By comparing them, we can learn a lot about how planets form and then evolve geologically over time. Crinkled over smooth plains, the long, wavy raised landforms seen here are called 'wrinkle ridges,' and they've been found on Mars, Mercury, Venus, and the Moon - that is, on rocky bodies that are a part of our inner solar system. We know from this observation that planets (and large-enough moons) follow similar processes. What we don't know for sure is HOW these processes work. Scientists have been trying to understand how wrinkle ridges form for 40 years, and they still haven't reached a conclusion. That

  12. Engineering development of waste retrieval end effectors for the Oak Ridge gunite waste tanks

    SciTech Connect

    Mullen, O.D.

    1997-05-01

    The Gunite and Associated Tanks Treatability Study at Oak Ridge National Laboratory selected the waterjet scarifying end effector, the jet pump conveyance system, and the Modified Light Duty Utility Arm and Houdini Remotely Operated Vehicle deployment and manipulator systems for evaluation. The waterjet-based retrieval end effector had been developed through several generations of test articles targeted at deployment in Hanford underground storage tanks with a large robotic arm. The basic technology had demonstrated effectiveness at retrieval of simulants bounding the foreseen range of waste properties and indicated compatibility with the planned deployment systems. The Retrieval Process Development and Enhancements team was tasked with developing a version of the retrieval end effector tailored to the Oak Ridge tanks, waste and deployment platforms. The finished prototype was delivered to PNNL and subjected to a brief round of characterization and performance testing at the Hydraulic Testbed prior to shipment to Oak Ridge. It has undergone extensive operational testing in the Oak Ridge National Laboratory Tanks Technology Cold Test Facility and performed well, as expected. A second unit has been delivered outfitted with the high pressure manifold.

  13. Evaluation of horizontal ridge augmentation using beta tricalcium phosphate and demineralized bone matrix: A comparative study

    PubMed Central

    Shalash, Mahmoud A.; Rahman, Hatem A.; Azim, Amr A.; Neemat, Amani H.; Hawary, Hesham E.

    2013-01-01

    Objectives: To evaluate the effectiveness of beta tricalcium phosphate (β-TCP) alone compared to β-TCP and Demineralized Bone Matrix (DBM) in regenerating localized horizontal maxillary alveolar ridge deficiencies prior to implant placement. Study Design: The study included 20 patients with horizontal maxillary ridge deficiencies limited to one or more neighbouring teeth and initial ridge width of ≤ 5mmm. Patients were divided equally into two equal groups. Ridge augmentation was performed using Guided Bone Regeneration (GBR) principals. In group I GBR was performed using β-TCP only, while in group II both β-TCP and DBM were used. Following a 6 months healing period, bone cores from both groups were retrieved and implants were inserted. Specimens were examined histologically to calculate percentage of mineralized bone. Apical and crestal changes in ridge dimensions were calculated by digital subtraction using Cone Beam Computed Tomography (CBCT) immediately after graft placement and six months later. Results: There was a statistically significant difference between the mean area percentage of mineralized bone between both groups where it was 40.1 % (range: 27.76-% 66.29 %) for group I and 68.96 % (range: 60.07 % - 87.33 %) for group II. Radiograpically, the mean ridge width in group I increased crestally to 4.66 mm (range:3.5-5mm) and apically to 6.12 mm (range: 4.1-6.7 mm). In group II the mean ridge width increased crestally to 5.2 mm (range 4.9-5.4mm) and apically to 6.9 mm (range 6.0-7.8 mm). Group II showed more bone gain with a mean of 1.37 mm crestally and 2.44 mm apically. This difference however was not statistically significant Conclusion: Within the limitations of this study the combination of DBM and β-TCP can be used effectively in cases exhibiting minimal alveolar ridge defects. Key words:Guided bone regeneration, equine bone, alloplast, bone graft. PMID:24455091

  14. Oak Ridge Reservation Waste Management Plan

    SciTech Connect

    Turner, J.W.

    1995-02-01

    This report presents the waste management plan for the Oak Ridge Reservation facilities. The primary purpose is to convey what facilities are being used to manage wastes, what forces are acting to change current waste management systems, and what plans are in store for the coming fiscal year.

  15. Oak Ridge reservation land-use plan

    SciTech Connect

    Bibb, W. R.; Hardin, T. H.; Hawkins, C. C.; Johnson, W. A.; Peitzsch, F. C.; Scott, T. H.; Theisen, M. R.; Tuck, S. C.

    1980-03-01

    This study establishes a basis for long-range land-use planning to accommodate both present and projected DOE program requirements in Oak Ridge. In addition to technological requirements, this land-use plan incorporates in-depth ecological concepts that recognize multiple uses of land as a viable option. Neither environmental research nor technological operations need to be mutually exclusive in all instances. Unique biological areas, as well as rare and endangered species, need to be protected, and human and environmental health and safety must be maintained. The plan is based on the concept that the primary use of DOE land resources must be to implement the overall DOE mission in Oak Ridge. This document, along with the base map and overlay maps, provides a reasonably detailed description of the DOE Oak Ridge land resources and of the current and potential uses of the land. A description of the land characteristics, including geomorphology, agricultural productivity and soils, water courses, vegetation, and terrestrial and aquatic animal habitats, is presented to serve as a resource document. Essentially all DOE land in the Oak Ridge area is being fully used for ongoing DOE programs or has been set aside as protected areas.

  16. Remedial Investigation Work Plan for Chestnut Ridge Operable Unit 1 (Chestnut Ridge Security Pits) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1993-09-01

    This Remedial Investigation (RI) Work Plan specifically addresses Chestnut Ridge Operable Unit 1, (OU1) which consists of the Chestnut Ridge Security Pits (CRSP). The CRSP are located {approximately}800 ft southeast of the central portion of the Y-12 Plant atop Chestnut Ridge, which is bounded to the northwest by Bear Creek Valley and to the southeast by Bethel Valley. Operated from 1973 to 1988, the CRSP consisted of a series of trenches used for the disposal of classified hazardous and nonhazardous waste materials. Disposal of hazardous waste materials was discontinued in December 1984, while nonhazardous waste disposal ended on November 8, 1988. An RI is being conducted at this site in response to CERCLA regulations. The overall objectives of the RI are to collect data necessary to evaluate the nature and extent of contaminants of concern (COC), support an ecological risk assessment (ERA) and a human health risk assessment (HHRA), support the evaluation of remedial alternatives, and ultimately develop a Record of Decision for the site. The purpose of this Work Plan is to outline RI activities necessary to define the nature and extent of suspected contaminants at Chestnut Ridge OU1. Potential migration pathways also will be investigated. Data collected during the RI will be used to evaluate the overall risk posed to human health and the environment by OU1.

  17. 25 MV tandem accelerator at Oak Ridge

    SciTech Connect

    Jones, C.M.

    1980-01-01

    A new heavy-ion accelerator facility is under construction at the Oak Ridge National Laboratory. A brief description of the scope and status of this project is presented with emphasis on the first operational experience with the 25 MV tandem accelerator.

  18. Ridge Regression: A Regression Procedure for Analyzing correlated Independent Variables

    ERIC Educational Resources Information Center

    Rakow, Ernest A.

    1978-01-01

    Ridge regression is a technique used to ameliorate the problem of highly correlated independent variables in multiple regression analysis. This paper explains the fundamentals of ridge regression and illustrates its use. (JKS)

  19. Wrinkle Ridges in Aeolis Dorsa, Mars: Preliminary Mapping

    NASA Astrophysics Data System (ADS)

    Borden, R. M.; Burr, D. M.

    2016-06-01

    Previous work has interpreted wrinkle ridges as compressional landforms caused by movement along blind thrust faults. Our preliminary mapping in the Aeolis Dorsa, Mars has identified widely distributed wrinkle ridges, suggesting episodic contraction.

  20. 15. Yankee Horse Ridge. View of the trail crossing the ...

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

    15. Yankee Horse Ridge. View of the trail crossing the Yankee Horse Railroad bed. Facing south. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  1. 16. Yankee Horse Ridge. View of the Yankee Horse Railroad ...

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

    16. Yankee Horse Ridge. View of the Yankee Horse Railroad trestle looking north. Looking north. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  2. Multibeam and CHIRP sonar imaging of sand ridge morphology and basal stratigraphy on the inner shelf offshore Panama City, Florida

    NASA Astrophysics Data System (ADS)

    Goff, J. A.; de Moustier, C.; Kraft, B.

    2011-12-01

    Reconnaissance surveys were conducted with a multibeam swath bathymetry sonar and a CHIRP subbottom profiler, and vibracores were collected on the inner shelf offshore Panama City, Florida in April, 2011, to provide seabed characterization for an upcoming ONR acoustic reverberation experiment. The seafloor in this region is part of the MAFLA sand sheet: Holocene shelf marine sands extending from Mississippi to the Florida panhandle, 0-5 m thick and dominated by oblique sand ridge morphology. Coring typically samples a thin shelly layer, associated with the shoreface ravinement, at the base of the sand sheet, followed by finer-grained and organic-rich estuarine sediments. Prior CHIRP data collected off Fort Walton Beach, NW of Panama City, revealed an intermittent reflector beneath the sand ridges that can be correlated to the base of the sand sheet identified in cores. The Panama City CHIRP data also display an intermittent reflector at the base of the sand ridges, often outcropping in the swales between the ridges. Estuarine layering can also be identified, contained within erosional channels beneath the sand ridges. Three spatially correlated morphologic/stratigraphic transitions occur across the survey area. To the NW, the shoreface is narrow and steep, sand ridges are larger, and the base of the sand ridges is coincident with the top of the channel-fill deposits and can therefore be identified as the base of the sand sheet. To the SE, the shoreface is broad and gradual, sand ridges are smaller, and the reflector at the base of the sand ridges is distinct from the top of the channel fill. A core through the reflector at the base of the sand ridges, in a location where it is distinct from the top of the channel fill, sampled a ~0.5 m-thick shell layer coincident with the reflector, with well-sorted sand above and poorly-sorted sand with woody fragments beneath. The reflector at the base of the sand ridges therefore appears to be the transgressive ravinement

  3. A detailed study of the Cobb Offset of the Juan de Fuca Ridge: Evolution of a propagating rift

    NASA Astrophysics Data System (ADS)

    Johnson, H. Paul; Karsten, Jill L.; Delaney, John R.; Davis, Earl E.; Currie, Ralph G.; Chase, Richard L.

    1983-03-01

    The Cobb Offset on the northern portion of the Juan de Fuca Ridge has been identified as the tip of a northward propagating rift [Hey and Wilson, 1982]. Map compilations of magnetic and seismic data from four new cruises define the present locus of spreading and volcanism on the two ridge segments abutting the Offset and permit detailed modeling of the recent evolution within this transform zone. The axis of recent spreading on the southern ridge segment bends from the normal ridge trend (N20°E) to a N-S trend, north of 47°15'N. The spreading axis on the northern ridge segment generally defines a N20°E trend, except at the southern terminus, where the spreading center is offset slightly to the east. The two spreading centers overlap by about 33 km in the Offset vicinity, and there is evidence of recent volcanism on both segments. Present ridge axis morphology exhibits a transitional sequence from a symmetrical, axial high along the more `normal' portions of each ridge segment to a grabenlike depression as the tip is approached. The magnetic anomaly patterns observed in the Cobb Offset vicinity are not consistent with the patterns predicted by models of continuous, northward propagation. The magnetic anomaly patterns of the Brunhes Epoch require an event of rapid northward propagation about 0.7 m.y. B.P., followed by a more gradual southward propagation in the middle Brunhes Epoch; most recently, the spreading center on the southern ridge has extended northward to its present configuration. Prior to the Brunhes Epoch, modeling of the magnetic anomaly patterns does not indicate a unique solution; however, net propagation has been northward. We present alternative models for the period beginning 1.7 m.y. B.P. In the first model, the Cobb Offset has evolved by a series of northward and southward events of propagation, with net advance to the north. In the second model, stable asymmetric spreading from overlapping ridge segments has evolved into a transform fault

  4. Seismic hazard evaluation for Department of Energy Oak Ridge Reservations, Oak Ridge, Tennessee

    SciTech Connect

    McGuire, R.K.; Toro, G.F.; Hunt, R.J.

    1992-09-30

    This study presents the results of an investigation of seismic hazard at the Department of Energy Oak Ridge Reservations (K-25 Site, Oak Ridge National Laboratories, and Oak Ridge Y-12 Plant), located in Oak Ridge, Tennessee. Oak Ridge is located in eastern Tennessee, in an area of moderate to high historical seismicity. Results from two separate seismic hazard analyses are presented. The EPRI/SOG analysis uses the input data and methodology developed by the Electric Power Research Institute, under the sponsorship of several electric utilities, for the evaluation of seismic hazard in the central and eastern United States. The LLNL analysis uses the input data and methodology developed by the Lawrence Livermore National Laboratory for the Nuclear Regulatory Commission. Both the EPRI/SOG and LLNL studies characterize earth-science uncertainty on the causes and characteristics of earthquakes in the central and eastern United States. This is accomplished by considering multiple hypotheses on the locations and parameters of seismic source zones and by considering multiple attenuation functions for the prediction of ground shaking given earthquake size and location. These hypotheses were generated by multiple expert teams and experts. Furthermore, each team and expert was asked to generate multiple hypotheses in order to characterize his own internal uncertainty. The seismic-hazard calculations are performed for all hypotheses. Combining the results from each hypothesis with the weight associated to that hypothesis, one obtains an overall representation of the seismic hazard at the Oak Ridge site and its uncertainty.

  5. Image-Specific Prior Adaptation for Denoising.

    PubMed

    Lu, Xin; Lin, Zhe; Jin, Hailin; Yang, Jianchao; Wang, James Z

    2015-12-01

    Image priors are essential to many image restoration applications, including denoising, deblurring, and inpainting. Existing methods use either priors from the given image (internal) or priors from a separate collection of images (external). We find through statistical analysis that unifying the internal and external patch priors may yield a better patch prior. We propose a novel prior learning algorithm that combines the strength of both internal and external priors. In particular, we first learn a generic Gaussian mixture model from a collection of training images and then adapt the model to the given image by simultaneously adding additional components and refining the component parameters. We apply this image-specific prior to image denoising. The experimental results show that our approach yields better or competitive denoising results in terms of both the peak signal-to-noise ratio and structural similarity.

  6. Opportunities for Cost Effective Disposal of Radioactively Contaminated Solid Waste on the Oak Ridge Reservation, Oak Ridge, TN - 13045

    SciTech Connect

    DeMonia, Brian; Dunning, Don; Hampshire John

    2013-07-01

    Department of Energy (DOE) requirements for the release of non-real property, including solid waste, containing low levels of residual radioactive materials are specified in DOE Order 458.1 and associated guidance. Authorized limits have been approved under the requirements of DOE Order 5400.5, predecessor to DOE Order 458.1, to permit disposal of solid waste containing low levels of residual radioactive materials at solid waste landfills located within the DOE Oak Ridge Reservation (ORR). Specifically, volumetric concentration limits for disposal of solid waste at Industrial Landfill V and at Construction/Demolition Landfill VII were established in 2003 and 2007, respectively, based on the requirements in effect at that time, which included: an evaluation to ensure that radiation doses to the public would not exceed 25 mrem/year and would be as low as reasonably achievable (ALARA), with a goal of a few mrem/year or less (in fact, these authorized limits actually were derived to meet a dose constraint of 1 mrem/year); an evaluation of compliance with groundwater protection requirements; and reasonable assurance that the proposed disposal is not likely to result in a future requirement for remediation of the landfill. Prior to approval as DOE authorized limits, these volumetric concentration limits were coordinated with the Tennessee Department of Environment and Conservation (TDEC) and documented in a Memorandum of Understanding (MOU) between the TDEC Division of Radiological Health and the TDEC Division of Solid Waste Management. These limits apply to the disposal of soil and debris waste generated from construction, maintenance, environmental restoration, and decontamination and decommissioning (D and D) activities on the DOE Oak Ridge Reservation. The approved site-specific authorized limits were incorporated in the URS/CH2M Oak Ridge LLC (UCOR) waste profile system that authorizes disposal of special wastes at either of the RCRA Subtitle D landfills. However, a

  7. Seismic stratigraphy and deformational styles of the offshore Cyrenaica (Libya) and bordering Mediterranean Ridge

    NASA Astrophysics Data System (ADS)

    Yem, Lionel Mbida; Camera, Laurent; Mascle, Jean; Ribodetti, Alessandra

    2011-04-01

    Off northwest Libya the Cyrenaica foreland basin domain and its Pan-African continental crust, which constitute the African promontory, are overthrusted by the Mediterranean Ridge Complex. The thrust belt contact and its seismic stratigraphy have been analysed using pre-stack depth-migrated multichannel seismic (MCS) lines recorded during the MEDISIS survey (2002). The geometry and sedimentary distribution analysis through the wedge-top depocentres allow reconstruction of schematic cross-sections of the tectono-sedimentary wedge that includes two major thrust sequences separated by an apparently poorly deformed transition zone. Based on time-space variation of several piggyback basins, we propose that these thrust sequences relate to distinct phases of shortening. (1) A first event, which probably occurred just prior to the Messinian crisis in latest Miocene (Tortonian times?) and (2) A second event, that has finally led to the present-day overthrusting of the Mediterranean Ridge over the Libyan continental slope.

  8. An archaeological reconnaissance and evaluation of the Oak Ridge National Laboratory, Oak Ridge Reservation, Anderson and Roane Counties, Tennessee

    SciTech Connect

    DuVall, G.D.

    1994-01-01

    At the request of Martin Marietta Energy Systems, Inc., Oak Ridge, Tennessee, an archaeological reconnaissance and evaluation of the Oak Ridge National Laboratory (ORNL) developed areas was conducted between June I and September 2, 1993. The project was conducted by Glyn D. DuVall, Principal Investigator. ORNL project representative, Peter Souza, accompanied the principal investigator during all project evaluations. The reconnaissance to assess adverse impacts to cultural resources located within the boundaries of federally licensed, permitted, funded or assisted projects was conducted in compliance with the National Historic Preservation Act of 1966 (Public Law 89-665; 16 USC 470; 80 Stat. 915), National Environmental Policy Act of 1969 (Public Law 91-190; 91 Stat. 852; 42 USC 4321-4347) and Executive Order 11593 (May 13, 1971). Based upon the reconnaissance, a search of the site files at the Tennessee Division of Archaeology and a search of the National Register of Historic Places, the proposed construction on the site will have no impact on any property included in or eligible for inclusion in the National Register of Historic Places pursuant to 36 CFR 60.4. This judgement is based on the amount of prior disturbance associated with ORNL during the past 50 years. Construction in the vicinity of the New Bethel Baptist Church and Cemetery should allow sufficient buffer to avoid direct and visual impact to the property. The determination of sufficient buffer area, either distance or vegetative, should be coordinated with the Tennessee Historical Commission, Office of the State Historic Preservation Officer.

  9. Mechanics of Alleghenian emplacement of thrust sheets along the Blue Ridge-Valley and Ridge boundary in the Southern Appalachians

    SciTech Connect

    Bartholomew, M.J.

    1985-01-01

    The structural interaction between emplacement of the crystalline Blue Ridge thrust sheet (BRTS) and associated Alleghenian deformation in the Valley and Ridge can be, in part, deduced from the deformational style and sequence found in the structurally underlying Pulaski thrust sheet (PTS). Within the PTS both crosscutting and superimposed structural relationships indicate that Alleghenian deformation proceeded through 5 distinct stages involving the PTS. Structures formed during: stage A- as the BRTS ascended a footwall ramp over the PTS and the major lower level decollement zone (LLDZ) in Cambrian strata formed at the base of the PTS; stage B- as the coupled BRTS-PTS ascended a footwall ramp across Cambrian through middle Ordovician strata; stage C- as the PTS crossed the upper Ordovician through Devonian portion of that ramp; stage D- as the BRTS-PTS crossed upper Devonian and Mississippian rocks and reached the upper level decollement zone in Mississippian strata; stage E- post BRTS-PTS emplacement. Stage A was characterized by development of both an imbricate fan in the Rome Formation beneath the BRTS and a thick LLDZ containing abundant tectonic breccia near the Rome/Elbrook contact. The upper bounding surface (UBS) of this LLDZ is folded by broad folds and cut by faults formed during later stages as footwall tectonic slices were incorporated into the base of the PTS. Thus, regional fold and fault trends and relationships with the UBS suggest that most of the complex deformation and tectonic breccia found within the LLDZ formed prior to the PTS ascending the footwall ramp.

  10. Prior Learning Assessment Workgroup: 2014 Progress Report

    ERIC Educational Resources Information Center

    West, Jim

    2015-01-01

    Legislation passed in 2011 required the Washington Student Achievement Council (WSAC) to convene a Prior Learning Assessment Workgroup. The workgroup was tasked with coordinating and implementing seven goals, described in statute, to promote the award of college credit for prior learning. Awarding college credit for prior learning increases access…

  11. Divergent Ridge Features on the Juan de Fuca and Gorda Ridges

    NASA Astrophysics Data System (ADS)

    Eaton, M. E.; Sautter, L.; Steele, M.

    2014-12-01

    Multibeam data collected using a Kongsberg EM122 sonar system on the NOAA ship R/V Marcus G. Langseth led by chief scientist Douglas Toomey (University of Oregon) in 2009 and with a Simrad EM302 sonar system on two NOAA ship Okeanos Explorer cruises led by chief scientists James Gardner (University of New Hampshire) and Catalina Martinez (University of Rhode Island) in 2009 show the morphology of the Juan de Fuca and Gorda Ridges, as well as the Blanco and Mendocino Fracture Zones. These ridges and fracture zones comprise the divergent plate boundary of the eastern edge of the Pacific Plate and the western edges of the Juan de Fuca and Gorda Plates. Both plates are being subducted beneath the western edge of the North American Plate. CARIS HIPS 8.1 software was used to process the multibeam data and create bathymetric images. The ridge axes, located off the coast of Washington and Oregon (USA) adjacent to the Cascadia Basin, indicate obvious signs of spreading, due to the series of faults and rocky ridges aligned parallel to the plate boundaries. Fault and ridge orientations are used to compare the direction of seafloor spreading, and indicate that both the Juan de Fuca Plate and Gorda Plate are spreading in a southeastern direction. Younger ridges from the Gorda Ridge system mapped in the study run parallel to the boundary, however older ridges do not show the same orientation, indicating a change in spreading direction. The presence of hydrothermal vents along the Juan de Fuca Ridge is also evidence of the active boundary, as the vent chimneys are composed of minerals and metals precipitated from the hot water heated by magma from beneath the spreading seafloor. In this study, the data are used to compare and contrast earthquake seismicity and ridge morphologies at a depth range of approximately 762 to 2134 meters. The diverging Pacific, Juan de Fuca, and Gorda Plates along with the San Andreas Fault have potential to increase seismic and volcanic activity around

  12. Growth of a tectonic ridge during the Landers earthquake

    USGS Publications Warehouse

    Fleming, R.W.; Johnson, A.M.

    1997-01-01

    The formation of tectonic ridges by localized vertical uplift along strike-slip faults has long been suspected, but the actual growth of a tectonic ridge during an earthquake has never been documented. During the 1992 Landers, California, earthquake sequence, an awl-shaped, dome-like topographic ridge along the Emerson fault zone increased its height at least 1 m concurrently with 3 m of right-lateral shift across the fault zone containing the ridge. Five deformation vectors within the ridge reveal dilatant behavior in addition to the uplift and shift on boundary faults.

  13. Growth of a tectonic ridge during the Landers earthquake

    SciTech Connect

    Fleming, R.W.; Johnson, A.M.

    1997-04-01

    The formation of tectonic ridges by localized vertical uplift along strike-slip faults has long been suspected, but the actual growth of a tectonic ridge during an earthquake has never been documented. During the 1992 Landers, California, earthquake sequence, an awl-shaped, dome-like topographic ridge along the Emerson fault zone increased its height at least 1 m concurrently with 3 m of right-lateral shift across the fault zone containing the ridge. Five deformation vectors within the ridge reveal dilatant behavior in addition to the uplift and shift on boundary faults. 10 refs., 5 figs.

  14. Minimally Informative Prior Distributions for PSA

    SciTech Connect

    Dana L. Kelly; Robert W. Youngblood; Kurt G. Vedros

    2010-06-01

    A salient feature of Bayesian inference is its ability to incorporate information from a variety of sources into the inference model, via the prior distribution (hereafter simply “the prior”). However, over-reliance on old information can lead to priors that dominate new data. Some analysts seek to avoid this by trying to work with a minimally informative prior distribution. Another reason for choosing a minimally informative prior is to avoid the often-voiced criticism of subjectivity in the choice of prior. Minimally informative priors fall into two broad classes: 1) so-called noninformative priors, which attempt to be completely objective, in that the posterior distribution is determined as completely as possible by the observed data, the most well known example in this class being the Jeffreys prior, and 2) priors that are diffuse over the region where the likelihood function is nonnegligible, but that incorporate some information about the parameters being estimated, such as a mean value. In this paper, we compare four approaches in the second class, with respect to their practical implications for Bayesian inference in Probabilistic Safety Assessment (PSA). The most commonly used such prior, the so-called constrained noninformative prior, is a special case of the maximum entropy prior. This is formulated as a conjugate distribution for the most commonly encountered aleatory models in PSA, and is correspondingly mathematically convenient; however, it has a relatively light tail and this can cause the posterior mean to be overly influenced by the prior in updates with sparse data. A more informative prior that is capable, in principle, of dealing more effectively with sparse data is a mixture of conjugate priors. A particular diffuse nonconjugate prior, the logistic-normal, is shown to behave similarly for some purposes. Finally, we review the so-called robust prior. Rather than relying on the mathematical abstraction of entropy, as does the constrained

  15. Raised Ridges in the Sheepbed Member as Evidence for Early Subaqueous Diagenesis at Yellowknife Bay, Gale Crater, Mars

    NASA Astrophysics Data System (ADS)

    Siebach, K. L.; Grotzinger, J. P.; Kah, L. C.; Stack, K.; Leveille, R. J.; Sumner, D. Y.; Edgar, L. A.; Team, M.

    2013-12-01

    Spatially restricted clusters of erosion-resistant, ridged fracture fills have been found throughout the fine-grained clay-rich Sheepbed member of the Yellowknife Bay Formation where the Mars Science Laboratory rover recently drilled. These 'raised ridge' features are characterized by 1-6 mm thick fractures filled with 2-4 subparallel resistant ridges. The ridges have been mapped throughout the Sheepbed member on Mastcam mosaics from sols 137 to 194 and are shown to be constrained to relatively dense, spatially localized clusters within the unit. The ridges have highly variable attitudes, ranging in dip from vertical to sub-horizontal, and striking in all directions, indicating that the original fractures formed in a mechanically isotropic setting. The fractures are generally short (<50 cm), have spindle-shaped terminations, and do not form regular polygons. The individual ridges are approximately a millimeter across and separated by at least a millimeter of less-resistant material. Based on the geometry of these features and lateral fabric variability within the unit, these are interpreted as early diagenetic synaeresis cracks, likely formed by gas expansion prior to final lithification of the Sheepbed member. Based on the isopachous nature of both the resistant and less-resistant fracture fills, the fracture-filling also occurred subaqueously, in the phreatic zone, and was likely a very early diagenetic process. This is supported by the observation that later diagenetic features, including light-toned sulfate-rich veins, cross-cut raised ridges. Investigation into the characteristics and distribution of these features, and comparison with synaeresis cracks on Earth, provide insight into the formation of the Sheepbed member and early aqueous and diagenetic processes in Gale Crater.

  16. The power prior: theory and applications.

    PubMed

    Ibrahim, Joseph G; Chen, Ming-Hui; Gwon, Yeongjin; Chen, Fang

    2015-12-10

    The power prior has been widely used in many applications covering a large number of disciplines. The power prior is intended to be an informative prior constructed from historical data. It has been used in clinical trials, genetics, health care, psychology, environmental health, engineering, economics, and business. It has also been applied for a wide variety of models and settings, both in the experimental design and analysis contexts. In this review article, we give an A-to-Z exposition of the power prior and its applications to date. We review its theoretical properties, variations in its formulation, statistical contexts for which it has been used, applications, and its advantages over other informative priors. We review models for which it has been used, including generalized linear models, survival models, and random effects models. Statistical areas where the power prior has been used include model selection, experimental design, hierarchical modeling, and conjugate priors. Frequentist properties of power priors in posterior inference are established, and a simulation study is conducted to further examine the empirical performance of the posterior estimates with power priors. Real data analyses are given illustrating the power prior as well as the use of the power prior in the Bayesian design of clinical trials.

  17. Ridge systems of Mars. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Gifford, A. W.

    1981-01-01

    Mare-type ridges on the Planet Mars were mapped and described based on Viking images. The ridges mapped range from 5 to 400 km long and 1 to 8 km wide. Most ridges on Mars are on plains and plateau units; 4,321 ridges with a total length of 153,835 km were mapped on these unit types. Ridges which resemble lunar mare ridges were also mapped in craters, basins, and several volcanic calderas on Mars. Mapping of ridges on a global scale reveals that they are preferentially developed in older, thinner plains units probably of flood basalt origin. Measuring the trends of ridges in plains units on Mars shows that there is a planetwide predominance of north, northwest and northeast trends. It is proposed that ridges are compressional tectonic features which have formed in response to changes in the planet's rotational equilibrium figure early in its history. In addition, the Tharsis uplift has created a regional stress system which accounts for the trends of ridges in areas near by. Ridges in craters and basins are similarly caused by shortening across the basin in response to regional stresses.

  18. An ultraslow-spreading class of ocean ridge.

    PubMed

    Dick, Henry J B; Lin, Jian; Schouten, Hans

    2003-11-27

    New investigations of the Southwest Indian and Arctic ridges reveal an ultraslow-spreading class of ocean ridge that is characterized by intermittent volcanism and a lack of transform faults. We find that the mantle beneath such ridges is emplaced continuously to the seafloor over large regions. The differences between ultraslow- and slow-spreading ridges are as great as those between slow- and fast-spreading ridges. The ultraslow-spreading ridges usually form at full spreading rates less than about 12 mm yr(-1), though their characteristics are commonly found at rates up to approximately 20 mm yr(-1). The ultraslow-spreading ridges consist of linked magmatic and amagmatic accretionary ridge segments. The amagmatic segments are a previously unrecognized class of accretionary plate boundary structure and can assume any orientation, with angles relative to the spreading direction ranging from orthogonal to acute. These amagmatic segments sometimes coexist with magmatic ridge segments for millions of years to form stable plate boundaries, or may displace or be displaced by transforms and magmatic ridge segments as spreading rate, mantle thermal structure and ridge geometry change.

  19. Does the lateral intercondylar ridge disappear in ACL deficient patients?

    PubMed

    van Eck, Carola F; Morse, Kenneth R; Lesniak, Bryson P; Kropf, Eric J; Tranovich, Michael J; van Dijk, C Niek; Fu, Freddie H

    2010-09-01

    The aim of this study was to determine whether there is a difference in the presence of the lateral intercondylar ridge and the lateral bifurcate ridge between patients with sub-acute and chronic ACL injuries. We hypothesized that the ridges would be present less often with chronic ACL deficiency. Twenty-five patients with a chronic ACL injury were matched for age and gender to 25 patients with a sub-acute ACL injury. The lateral intercondylar ridge and lateral bifurcate ridge were scored as either present, absent, or indeterminate due to insufficient visualization by three blinded observers. The kappa for the three observers was .61 for the lateral intercondylar ridge and .58 for the lateral bifurcate ridge. The lateral intercondylar ridge was present in 88% of the sub-acute patients and 88% of the chronic patients. The lateral bifurcate ridge was present in 48% of the sub-acute and 48% of the chronic patients. This matched-pairs case-control study was unable to show a difference in the presence of the femoral bony ridges between patients with acute and chronic ACL injuries. The authors would suggest looking for the ridges as a landmark of the native ACL insertion site during ACL reconstruction in both acute and chronic ACL injuries.

  20. Active convection beneath ridges: a new spin

    NASA Astrophysics Data System (ADS)

    Katz, R. F.

    2009-12-01

    The role of buoyancy-driven, "active" upwelling beneath mid-ocean ridges has been long debated [1,2,3], with the naysayers holding sway in recent years. Recent work on tomographic imaging of the sub-ridge mantle has revealed patterns in velocity variation that seem inconsistent with what we expect of passive upwelling and melting [4]. The irregular distribution, asymmetry, and off-axis locations of slow regions in tomographic results are suggestive of time-dependent convective flow. Using 2D numerical simulations of internally consistent mantle and magmatic flow plus melting/freezing [5,6], I investigate the parametric subspace in which active convection is expected to occur. For low mantle viscosities, interesting symmetry-breaking behavior is predicted. References: [1] Rabinowicz, et al., EPSL, 1984; [2] Buck & Su, GRL, 1989; [3] Scott & Stevenson, JGR, 1989; [4] Toomey et al., Nature, 2007; [5] McKenzie, J.Pet., 1984; [6] Katz, J.Pet., 2008;

  1. An Investigation of Dielectric Loaded Ridged Waveguide.

    DTIC Science & Technology

    1986-03-31

    propagation in any waveguide may be characterized by its field distribution. For homogeneous waveguides, modes are usually classified as TE (transverse...modes other than TE,,,.0 are characterized as LSE or LSM. Introduction of the ridge will cause distortion of the fields from true LSE or LSM nature...specify each of the LSE and LSM modes with any given mode characterized as the LSEm, mode or the LSM ,, mode. The first index m refers to the

  2. ORNL (Oak Ridge National Laboratory) 89

    SciTech Connect

    Anderson, T.D.; Appleton, B.R.; Jefferson, J.W.; Merriman, J.R.; Mynatt, F.R.; Richmond, C.R.; Rosenthal, M.W.

    1989-01-01

    This is the inaugural issues of an annual publication about the Oak Ridge National Laboratory. Here you will find a brief overview of ORNL, a sampling of our recent research achievements, and a glimpse of the directions we want to take over the next 15 years. A major purpose of ornl 89 is to provide the staff with a sketch of the character and dynamics of the Laboratory.

  3. Leadership Computing at Oak Ridge National Laboratory

    SciTech Connect

    Kuehn, Jeffery A; Studham, Scott; White III, James B; Fahey, Mark R; Carter, Steven M; Nichols, Jeffrey A

    2005-05-01

    Oak Ridge National Laboratory is running the world's largest Cray X1, the world's largest unclassified Cray XT3, and a Cray XD1. In this report we provide an overview of the applications requiring leadership computing and the performance characteristics of the various platforms at ORNL. We then discuss ways in which we are working with Cray to establish a roadmap that will provide 100's of teraflops of sustained performance while integrating a balance of vector and scalar processors.

  4. Segmentation of mid-ocean ridges

    USGS Publications Warehouse

    Schouten, Hans; Klitgord, Kim D.; Whitehead, J.A.

    1985-01-01

    Studies of mid-ocean ridges in the Pacific and Atlantic oceans show that the volcanism that forms the oceanic crust along the spreading-plate boundaries is concentrated at regular intervals related to spreading rate. This observation and a new calculation for a Rayleigh-Taylor type of gravitational instability of a partially molten mantle region growing under spreading centres yield reasonable estimates of upper mantle viscosities. ?? 1985 Nature Publishing Group.

  5. Oak Ridge 25-MV tandem accelerator

    SciTech Connect

    Ziegler, N.F.; Richardson, E.G.; Mann, J.E.; Juras, R.C.; Jones, C.M.; Biggerstaff, J.A.; Benjamin, J.A.

    1981-01-01

    A new heavy-ion accelerator facility is nearing completion at the Oak Ridge National Laboratory. This paper presents a brief description of the scope and status of this project and a discussion of some aspects of the first operational experience with the 25 MV tandem accelerator which is being provided by the National Electrostatics Corporation (NEC) as a major component of the first phase of the facility.

  6. Tidal Triggering and Statistical Patterns of Microseismicity at Axial Volcano on the Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Bohnenstiehl, D. R.; Dziak, R. P.; Caplan-Auerbach, J.; Haxel, J. H.; Mann, M. E.; Pennington, C.; Weis, J.; Womack, N.; Levy, S.

    2015-12-01

    Tidal stress changes are known to modulate the timing of microearthquakes within many mid-ocean ridge volcanic systems. At Axial Volcano, located on the Juan de Fuca Ridge, earthquakes occur preferentially when volumetric extension peaks near times of low ocean tide. Autonomous ocean-bottom hydrophone (OBH, 2007-2011) and cabled ocean bottom seismometer (OBS, Nov. 2014-) data are used to quantify the strength of tidal triggering in time periods before the April 2011 and April 2015 eruptions at Axial Volcano. The mean percent excess at times of low ocean-tide is ~14% (16% std) in the four years prior to the 2011 eruption and ~18% (17% std) in the five months prior to the 2015 eruption. The sensitivity of earthquakes to tidal stress does not evolve systematically prior to either eruption; however, this pattern is disturbed by much larger stress changes associated with the onset of dike intrusion. Following dike injection and eruption, seismicity rates drop sharply. As seismicity rates continue to rise in the months following the 2015 eruption, real-time data available from the cabled OBS network will be used quantify temporal patterns in microearthquake activity as dike induced stresses are relaxed and the magma chamber inflates.

  7. The Northern Kolbeinsey Ridge, North Atlantic: Excess volcanism and ridge relocations close to Jan Mayen

    NASA Astrophysics Data System (ADS)

    Yeo, I. A.; Augustin, N.; Devey, C. W.; Deutschmann, M.; Elkins, L. J.; Laurila, T.; Meisenhelder, K.; Rivers, E.; Rothenbeck, M.; van der Zwan, F. M.

    2012-12-01

    The slow-spreading (1.8 cm/yr full rate) Northern Kolbeinsey Ridge (NKR) segment of the Mid-Atlantic Ridge, which lies immediately south of the major Jan Mayen Transform Fault, is characterised by anomalously thick crust and unusually shallow water depths. A lack of precise surveying meant that the tectonics and volcanology of the ridge were previously unknown. We present the preliminary findings from 20 days of sampling and mapping of the NKR between 70°30 N and 71°45 N in July 2012. Over 3,130 km2 of the ridge axis were imaged with ship-based multibeam at 35 m or better resolution, while a further 290 km2 were imaged with high-resolution (~ 1 m) sidescan sonar and multibeam surveys using the AUV "ABYSS". This unique dataset, alongside dredge and volcanic rock corer sampling, allows us to define the location of current volcanic crustal accretion for the first time and reveals a complex pattern of volcanism and tectonics along the ridge. At its northern, deeper end we image a single, 025° trending, 4 -5 km wide axial valley, divided into zones dominated alternately by flatter seafloor and closely spaced flat-topped seamounts. As the seafloor shallows southward, the number of flat-topped seamounts decreases and the axial volcanism becomes dominated by sheet- and hummocky flows. At its shallowest point, the axis is flanked on its eastern side by a large, 5 km diameter central volcano (forming Eggvin Bank, min. water depth 20m). The volcano displays a summit caldera containing fresh basalts (the freshest sampled on the entire ridge) as well as relatively fresh flows on its southern flank. South of Eggvin volcano the ridge is cut by an oblique (68° trending), normal fault bounded valley, which extends 7 km southwest from the current active ridge to the north. This oblique valley connects with two further 025° trending parallel valleys to the south: one in line with the axis to the north and a second 7 km to the west. Both valleys appear to have been recently

  8. Polar gravel beach-ridge systems: Sedimentary architecture, genesis, and implications for climate reconstructions (South Shetland Islands/Western Antarctic Peninsula)

    NASA Astrophysics Data System (ADS)

    Lindhorst, Sebastian; Schutter, Ilona

    2014-09-01

    The sedimentary architecture of polar gravel-beach ridges is presented and it is shown that ridge internal geometries reflect past wave-climate conditions. Ground-penetrating radar (GPR) data obtained along the coasts of Potter Peninsula (King George Island) show that beach ridges unconformably overlie the prograding strand plain. Development of individual ridges is seen to result from multiple storms in periods of increased storm-wave impact on the coast. Strand-plain progradation, by contrast, is the result of swash sedimentation at the beach-face under persistent calm conditions. The sedimentary architecture of beach ridges in sheltered parts of the coast is characterized by seaward-dipping prograding beds, being the result of swash deposition under stormy conditions, or aggrading beds formed by wave overtopping. By contrast, ridges exposed to high-energy waves are composed of seaward- as well as landward-dipping strata, bundled by numerous erosional unconformities. These erosional unconformities are the result of sediment starvation or partial reworking of ridge material during exceptional strong storms. The number of individual ridges which are preserved from a given time interval varies along the coast depending on the morphodynamic setting: sheltered coasts are characterized by numerous small ridges, whereas fewer but larger ridges develop on exposed beaches. The frequency of ridge building ranges from decades in the low-energy settings up to 1600 years under high-energy conditions. Beach ridges in the study area cluster at 9.5, 7.5, 5.5, and below 3.5 m above the present-day storm beach. Based on radiocarbon data, this is interpreted to reflect distinct periods of increased storminess and/or shortened annual sea-ice coverage in the area of the South Shetland Islands for the times around 4.3, c. 3.1, 1.9 ka cal BP, and after 0.65 ka cal BP. Ages further indicate that even ridges at higher elevations can be subject to later reactivation and reworking. A

  9. Universal Priors for Sparse Modeling(PREPRINT)

    DTIC Science & Technology

    2009-08-01

    UNIVERSAL PRIORS FOR SPARSE MODELING By Ignacio Ramı́rez Federico Lecumberry and Guillermo Sapiro IMA Preprint Series # 2276 ( August 2009...8-98) Prescribed by ANSI Std Z39-18 Universal Priors for Sparse Modeling (Invited Paper) Ignacio Ramı́rez#1, Federico Lecumberry ∗2, Guillermo Sapiro...I. Ramirez, F. Lecumberry , and G. Sapiro. Sparse modeling with univer- sal priors and learned incoherent dictionaries. Submitted to NIPS, 2009. [22

  10. Zeolites in the Pine Ridge Indian Reservation, South Dakota

    USGS Publications Warehouse

    Raymond, William H.; Bush, Alfred L.; Gude, Arthur J.

    1982-01-01

    Zeolites of possible commercial value occur in the Brule Formation of Oligocene age and the Sharps Formation (Harksen, 1961) of Miocene age which crop out in a wide area in the northern part of the Pine Ridge Indian Reservation. The thickness of the zeolite-bearing Interval and the extent of areas within the Interval which contain significant amounts of zeolites are far greater than was expected prior to this investigation. The shape of the zeolite-bearing Interval is tabular and the dimensions of Its exposure are roughly 10 ml x 200 mi x 150 ft (16 km x 160 km x 45 m) thick. Within the study area, there are tracts in which the zeolite resource potential is significant (see pl. 2). This report is intended to inform the Oglala Sioux Tribe of some of the most promising zeolite occurrences. Initial steps can then be taken by the Tribe toward possible development of the resources, should they wish to do so. The data contained herein identify areas of high zeolite potential, but are not adequate to establish economic value for the deposits. If development is recommended by the tribal government, we suggest that the tribal government contact companies involved in research and production of natural zeolites and provide them with the data in this report.

  11. The Cocos and Carnegie Ridges: A Record of Long-term Galapagos Plume-Ridge Interaction

    NASA Astrophysics Data System (ADS)

    Harpp, K. S.; Wanless, V.; Hoernle, K.

    2001-12-01

    The present-day Galapagos Archipelago exhibits an astonishingly wide variety of geochemical compositions, from enriched, hotspot-like signatures in the west and south to MORB-like lavas in the central and northern regions. The distinctive spatial zonation has been attributed to a heterogeneous plume and its extensive interaction with the asthenosphere. One of the controversial questions about the Galapagos system is whether the geochemical zonation in the present-day archipelago is a long-term phenomenon due to inherent plume heterogeneity or only the recent result of short-lived mantle contamination. The aseismic Cocos and Carnegie Ridges record the last 20 Ma of plume activity as the Cocos and Nazca plates, respectively, have moved over the hotspot. During the 1999 PAGANINI expedition, we collected over 80 dredge samples from the ridges to explore the temporal variations of the Galapagos plume. Preliminary results suggested that lavas dredged off the west coast of Central America preserve the geochemical zonation observed in the Galapagos Archipelago today. Trace element determinations from dredge sites along the Cocos and Carnegie Ridges indicate, however, that the situation is (not surprisingly) more complex. Instead, the geochemical variations observed along the ridges may be controlled predominantly by the relative positions of the Galapagos plume and the Galapagos Spreading Center (GSC). The GSC has been migrating to the NE relative to the hotspot. For the oldest portions of the Cocos Ridge, the plume was located beneath the Nazca plate and did not interact with the GSC. Lavas produced during this time therefore represent pristine plume, with compositions more enriched than those of the present-day Galapagos; these are observed NE of Cocos Island. As the ridge migrates closer to the hotspot, plume-mid-ocean ridge interaction intensifies, resulting in the dilution of hotspot lavas by entrained, depleted asthenosphere. Consistently, younger lavas along the

  12. Transition Plan for the K-1203 Sewage Treatment Plant, East Tennessee Technology Park, Oak Ridge, Tennessee

    SciTech Connect

    Hoffmeister J.

    2008-10-05

    The K-1203 Sewage Treatment Plant (STP) was previously used to treat and process all sanitary sewage waste from the East Tennessee Technology Park (ETTP). The plant was shut down on May 29, 2008 as a result of the transition of sewage treatment for ETTP to the City of Oak Ridge. The City of Oak Ridge expanded the Rarity Ridge Sewage Treatment Plant (RRSTP) to include capacity to treat the waste from the ETTP and the Community Reuse Organization of East Tennessee (CROET) constructed a new ETTP lift station and force main to RRSTP. In preparation for the shutdown of K-1203, the US Department of Energy (DOE) in conjunction with Operation Management International (OMI) developed a shut down plan to outline actions that need to occur prior to the transition of the facility to Bechtel Jacob Company, LLC (BJC) for decontamination and demolition (D and D). This plan outlines the actions, roles, and responsibilities for BJC in order to support the transition of the K-1203 STP from OMI to the BJC Surveillance and Maintenance (S and M) and D and D programs. The D and D of the K-1203 Facilities is planned under the Comprehensive Environmental Response, Compensation, and Liability Act Remaining Facilities D and D Action Memorandum in the Balance of Site-Utilities D and D Subproject in fiscal year (FY) 2014.

  13. A common origin for ridge-and-trough terrain on icy satellites by sluggish lid convection

    NASA Astrophysics Data System (ADS)

    Barr, Amy C.; Hammond, Noah P.

    2015-12-01

    Ridge-and-trough terrain is a common landform on outer Solar System icy satellites. Examples include Ganymede's grooved terrain, Europa's gray bands, Miranda's coronae, and several terrains on Enceladus. The conditions associated with the formation of each of these terrains are similar: heat flows of order tens to a hundred milliwatts per meter squared, and deformation rates of order 10-16-10-12 s-1. Our prior work shows that the conditions associated with the formation of these terrains on Ganymede and the south pole of Enceladus are consistent with vigorous solid-state ice convection in a shell with a weak surface. We show that sluggish lid convection, an intermediate regime between the isoviscous and stagnant lid regimes, can create the heat flow and deformation rates appropriate for ridge and trough formation on a number of satellites, regardless of the ice shell thickness. For convection to deform their surfaces, the ice shells must have yield stresses similar in magnitude to the daily tidal stresses. Tidal and convective stresses deform the surface, and the spatial pattern of tidal cracking controls the locations of ridge-and-trough terrain.

  14. Assessing impacts to birds from the Buffalo Ridge, Minnesota windplant development

    SciTech Connect

    Strickland, M.D.; Johnson, G.D.; Erickson, W.P.

    1997-12-31

    Northern States Power (NSP) plans development of a 425 MW windpowered electrical generation facility within the Buffalo Ridge Wind Resource Area (WRA) in southwestern Minnesota. In 1996, Western EcoSystems Technology (WEST, Inc.) was contracted by NSP to develop an avian monitoring protocol for the Buffalo Ridge windplant. This protocol was developed and peer-reviewed by numerous individuals representing the wind energy industry, U.S. Fish and Wildlife Service, Minnesota Department of Natural Resources, and conservation groups prior to finalization. The WRA currently consists of three phases of development. Phase I, constructed by Kenetech in 1994, consists of 73 Model 33 M-VS turbines and related facilities, including distribution lines, meteorological towers, communication systems, transformers, substations, roads, and operations and maintenance facilities in the approximate center of the WRA, and generates 25 MW of electricity. Phase II, consisting of 143 turbines and related facilities sufficient to generate 100 MW of electricity, will be constructed by Zond Systems, Inc. beginning in the spring of 1997. Phase II will be located in the northwestern portion of the WRA. Phase III facilities capable of generating an additional 100 MW are planned for the southeast portion of the WRA. Plans call for the eventual production of 425 MW of electricity within the WRA. Studies were conducted in these three areas and a permanent reference area not scheduled for windpower development located along Buffalo Ridge northwest of the WRA in Brooking County South Dakota.

  15. Dynamical instability produces transform faults at mid-ocean ridges.

    PubMed

    Gerya, Taras

    2010-08-27

    Transform faults at mid-ocean ridges--one of the most striking, yet enigmatic features of terrestrial plate tectonics--are considered to be the inherited product of preexisting fault structures. Ridge offsets along these faults therefore should remain constant with time. Here, numerical models suggest that transform faults are actively developing and result from dynamical instability of constructive plate boundaries, irrespective of previous structure. Boundary instability from asymmetric plate growth can spontaneously start in alternate directions along successive ridge sections; the resultant curved ridges become transform faults within a few million years. Fracture-related rheological weakening stabilizes ridge-parallel detachment faults. Offsets along the transform faults change continuously with time by asymmetric plate growth and discontinuously by ridge jumps.

  16. An abrupt change in ridge axis gravity with spreading rate

    NASA Technical Reports Server (NTRS)

    Small, Christopher; Sandwell, David T.

    1989-01-01

    A total of 44 Geosat profiles over ridges with spreading rates ranging from 14 to 155 mm/yr were analyzed. In agreement with previous studies, it is found that slow spreading ridges usually have high amplitude gravity troughs, while fast spreading ridges are characterized by low-amplitude ridge axis highs. Unexpectedly, it is found that the transition from axial trough to axial high occurs abruptly at a spreading rate of 60-70 mm/yr. Ridge axis gravity signatures are highly variable for rates less than 65 mm/yr and very uniform at higher rates. The transition of the gravity signature appears to get more abrupt than the transition of the topographic signature, suggesting an abrupt change in the style of isostatic compensation with spreading rate. Published models of ridge axis dynamics do not explain this sharp transition.

  17. Ridge network detection in crumpled paper via graph density maximization.

    PubMed

    Hsu, Chiou-Ting; Huang, Marvin

    2012-10-01

    Crumpled sheets of paper tend to exhibit a specific and complex structure, which is described by physicists as ridge networks. Existing literature shows that the automation of ridge network detection in crumpled paper is very challenging because of its complex structure and measuring distortion. In this paper, we propose to model the ridge network as a weighted graph and formulate the ridge network detection as an optimization problem in terms of the graph density. First, we detect a set of graph nodes and then determine the edge weight between each pair of nodes to construct a complete graph. Next, we define a graph density criterion and formulate the detection problem to determine a subgraph with maximal graph density. Further, we also propose to refine the graph density by including a pairwise connectivity into the criterion to improve the connectivity of the detected ridge network. Our experimental results show that, with the density criterion, our proposed method effectively automates the ridge network detection.

  18. Data Management for the Ridge 2000 Program

    NASA Astrophysics Data System (ADS)

    Chayes, D. N.; Robert, A. A.; Carbotte, S. M.; Ryan, W. B.; Lenhert, K. A.; Shank, T. M.

    2004-12-01

    Since the start of this effort (September 1, 2003) we have developed a data base schema, selected and installed a relational data base management system (PostgreSQL), designed, developed and, deployed a draft set of metadata forms, ingested data from ten Ridge2000 cruises as of September 2004 and deployed a web accessible Ridge2000 data portal: http://www.marine-geo.org/ridge2000/ . At the portal, one can get content using with pre-constructed queries for survey targets and deployed instruments at each of the R2K Integrated Study Sites. Alternatively, our data link allows spatial, temporal and keyword searches to identify and download data. The current metadata forms have been used for 6 cruises and we have received constructive feedback (in addition to the actual metadata) from all three R2K integrated study sites. We are working on incorporating this feedback into an updated set of forms which we expect to release early in 2005. Other recent include substantial improvements to GeoMapApp, links to other data repositories, a major update of our web site, integration with data from Arctic, Antarctic, Margins data sets and the pre-constructed queries on the R2K portal page. Our plans for 2005 include: A second major revision of the metadata forms in early '05, improvements in the metadata ingestion process, enhanced authentication using LDAP, continued active participation in the broader data community developing interoperability as well as implementing direct interoperability with a number of complementary databases including the underway geophysical and multibeam databases at National Geophysical Data Center, the National Deep Submergence facility at Woods Hole, the Geological Data Center of the Scripps Institute of Oceanography, and the databases of the ODP (JANUS at TAMU, and Borehole Geophysics at LDEO)

  19. Field Use of NMIS at Oak Ridge

    SciTech Connect

    Chiang, L.G.; Conger, M.; Hughes, S.S.; Mattingly, J.K.; McEvers, J.A.; Mihalczo, J.T.; Mullens, J.A.; Perez, R.B.; Turner, C.R.; Uckan, T.; Valentine, T.E.

    1999-08-26

    The Nuclear Materials Identification System (NMIS), developed by the Oak Ridge National Laboratory and Oak Ridge Y-12 Plant (Y-12), has been successfully used at Y-12 for nuclear material control and accountability (NMC&A). It is particularly useful in the high gamma-ray background of storage arrays and for shielded HEU. With three systems in use at Y-12, NMIS has enhanced the NMC&A capability for verification and for confirmation of materials in storage and for HEU receipts by providing capability not available or practical by other NDA methods for safeguards. It has recently cost-effectively quantified the HEU mass and enrichment of hundreds of HEU metal items to within a total spread of {+-} 5% (3 sigma) with and mean deviations for all HEU verified of + 0.2% for mass and {minus}0.2% for enrichment. Three cart portable systems are easily moved around with minimal impact on facility operations since no permanent dedicated floor space is required. The positive impact of NMIS at the Oak Ridge Y-12 Plant is improved and more cost effective NMC&A as well as the resolution of NMC&A findings. Its operation at the Y-12 Plant is essential for compliance with the NMC&A requirements of the US Department of Energy. NMIS portability has allowed one system to be moved temporarily to the former K-25 Gaseous Diffusion Plant for characterization of a large deposit of hydrated uranyl fluoride. The impact of this NMIS application was enhanced and verified nuclear criticality safety that led to the safe removal of a large deposit originally estimated by gamma-ray spectrometry and neutron counting to contain 1300 kg of 3.3 wt% {sup 235}U material. NMIS has also been operational at Los Alamos National Laboratory and Pantex.

  20. Neutron Instruments Added at Oak Ridge

    SciTech Connect

    Ekkebus, Allen E

    2011-01-01

    The neutron scattering facilities at Oak Ridge National Laboratory continue their development as new instruments are commissioned and join the user program at the Spallation Neutron Source and High Flux Isotope Reactor. More than 640 proposals were received for beam time during the January-May 2011 period on SNS and HFIR instruments with about half either being accepted or identified as alternates. The proposal call for the period June-December 2011, announced at http://neutrons.ornl.gov, will close February 23, 2011.

  1. Oak Ridge Leadership Computing Facility Position Paper

    SciTech Connect

    Oral, H Sarp; Hill, Jason J; Thach, Kevin G; Podhorszki, Norbert; Klasky, Scott A; Rogers, James H; Shipman, Galen M

    2011-01-01

    This paper discusses the business, administration, reliability, and usability aspects of storage systems at the Oak Ridge Leadership Computing Facility (OLCF). The OLCF has developed key competencies in architecting and administration of large-scale Lustre deployments as well as HPSS archival systems. Additionally as these systems are architected, deployed, and expanded over time reliability and availability factors are a primary driver. This paper focuses on the implementation of the Spider parallel Lustre file system as well as the implementation of the HPSS archive at the OLCF.

  2. 28 CFR 2.58 - Prior orders.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Prior orders. 2.58 Section 2.58 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS, YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.58 Prior orders. Any order...

  3. 28 CFR 2.58 - Prior orders.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Prior orders. 2.58 Section 2.58 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS, YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.58 Prior orders. Any order...

  4. 28 CFR 2.58 - Prior orders.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Prior orders. 2.58 Section 2.58 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS, YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.58 Prior orders. Any order...

  5. 28 CFR 2.58 - Prior orders.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Prior orders. 2.58 Section 2.58 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS, YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.58 Prior orders. Any order...

  6. Prior Computer Experience and Technology Acceptance

    ERIC Educational Resources Information Center

    Varma, Sonali

    2010-01-01

    Prior computer experience with information technology has been identified as a key variable (Lee, Kozar, & Larsen, 2003) that can influence an individual's future use of newer computer technology. The lack of a theory driven approach to measuring prior experience has however led to conceptually different factors being used interchangeably in…

  7. 7 CFR 550.27 - Prior approvals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Program Management § 550.27 Prior approvals. (a) The budget is the financial expression of the project or... requiring prior written approval). (3) The absence for more than three months, or a 25 percent reduction in... in writing with supporting reasons. (5) The transfer of amounts budgeted for indirect costs to...

  8. 19 CFR 162.74 - Prior disclosure.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) INSPECTION, SEARCH, AND SEIZURE Special Procedures for Certain Violations § 162.74 Prior... in denial of the oral prior disclosure. (b) Disclosure of the circumstances of a violation. The term... violations involving merchandise accompanying persons entering the United States or commercial...

  9. 19 CFR 162.74 - Prior disclosure.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (CONTINUED) INSPECTION, SEARCH, AND SEIZURE Special Procedures for Certain Violations § 162.74 Prior... in denial of the oral prior disclosure. (b) Disclosure of the circumstances of a violation. The term... violations involving merchandise accompanying persons entering the United States or commercial...

  10. 19 CFR 162.74 - Prior disclosure.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) INSPECTION, SEARCH, AND SEIZURE Special Procedures for Certain Violations § 162.74 Prior... in denial of the oral prior disclosure. (b) Disclosure of the circumstances of a violation. The term... violations involving merchandise accompanying persons entering the United States or commercial...

  11. 19 CFR 162.74 - Prior disclosure.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... (CONTINUED) INSPECTION, SEARCH, AND SEIZURE Special Procedures for Certain Violations § 162.74 Prior... in denial of the oral prior disclosure. (b) Disclosure of the circumstances of a violation. The term... violations involving merchandise accompanying persons entering the United States or commercial...

  12. Relationship between Prior Knowledge and Reading Comprehension

    ERIC Educational Resources Information Center

    Abdelaal, Noureldin Mohamed; Sase, Amal Saleh

    2014-01-01

    This study investigates the relationship between prior knowledge and reading comprehension in second language among postgraduate students in UPM. Participants in the study were 20 students who have the same level in English as a second language from several faculties. On the basis of a prior-knowledge questionnaire and test, students were…

  13. 28 CFR 2.58 - Prior orders.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Prior orders. 2.58 Section 2.58 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS, YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.58 Prior orders. Any order...

  14. Improving Open Access through Prior Learning Assessment

    ERIC Educational Resources Information Center

    Yin, Shuangxu; Kawachi, Paul

    2013-01-01

    This paper explores and presents new data on how to improve open access in distance education through using prior learning assessments. Broadly there are three types of prior learning assessment (PLAR): Type-1 for prospective students to be allowed to register for a course; Type-2 for current students to avoid duplicating work-load to gain…

  15. Comprehensive integrated planning: A process for the Oak Ridge Reservation, Oak Ridge, Tennessee

    SciTech Connect

    1998-05-01

    The Oak Ridge Comprehensive Integrated Plan is intended to assist the US Department of Energy (DOE) and contractor personnel in implementing a comprehensive integrated planning process consistent with DOE Order 430.1, Life Cycle Asset Management and Oak Ridge Operations Order 430. DOE contractors are charged with developing and producing the Comprehensive Integrated Plan, which serves as a summary document, providing information from other planning efforts regarding vision statements, missions, contextual conditions, resources and facilities, decision processes, and stakeholder involvement. The Comprehensive Integrated Plan is a planning reference that identifies primary issues regarding major changes in land and facility use and serves all programs and functions on-site as well as the Oak Ridge Operations Office and DOE Headquarters. The Oak Ridge Reservation is a valuable national resource and is managed on the basis of the principles of ecosystem management and sustainable development and how mission, economic, ecological, social, and cultural factors are used to guide land- and facility-use decisions. The long-term goals of the comprehensive integrated planning process, in priority order, are to support DOE critical missions and to stimulate the economy while maintaining a quality environment.

  16. Historical Gorda Ridge t-phase swarms: relationships to ridge structure and the tectonic and volcanic state of the ridge during 1964 1966

    NASA Astrophysics Data System (ADS)

    Walker, Daniel A.; Hammond, Stephen R.

    1998-12-01

    The U.S. Navy's Sound Surveillance System (SOSUS) hydrophone arrays are extemely efficient receptors of a high-frequency earthquake energy phase known as the t(ertiary)-wave, or t-phase (Fox et al., 1994). After a nearly 30-year hiatus in such studies, SOSUS arrays are again being utilized to detect t-phases and to locate seismic and volcanic events occurring along the Gorda seafloor spreading center (Fox et al., 1995; Fox and Dziak, 1998). Earlier, Northrop et al. (1968) also used other military arrays to infer tectonic structure along the Gorda Ridge. From October 1964 through December 1966, over 600 low-magnitude earthquakes occurred along the Gorda Ridge. Nearly all of these events had magnitudes below the detection thresholds of land-based seismic networks. Northrop et al. (1968) interpreted the geographic distribution of these events as evidence for a nascent fracture zone near the midpoint of the ridge. In the present study, the spatial distributions of these older data and, for the first time, their temporal distributions as well, were examined with respect to detailed bathymetry of the ridge that was acquired in the early 1980s. This analysis, of 570 on-axis and 74 off-axis events, led to the following observations: (1) nearly all of the Gorda Ridge t-phase events occurred in discreet swarms centered about the ridge axis, (2) most of the events within each of 8 (of 9) observed swarms occurred mainly along single ridge segments, and, (3) reconfirming the earlier Northrop et al. (1968) conclusion, most of the events originated in the region of a major change in the strike of the ridge axis. During the 27-month interval that the ridge was observed, relatively few t-phase events took place along the northernmost segment of the Gorda Ridge where the 1996 eruption occurred. However, a unique sequence of small events which visually resemble the events associated with a Juan de Fuca Ridge eruption in 1993 (Fox et al., 1995) and a Gorda Ridge eruption in 1996 (Fox

  17. New beach ridge type: severely limited fetch, very shallow water

    SciTech Connect

    Tanner, W.F.; Demirpolat, S.

    1988-09-01

    The southern end of Laguna Madre (Texas) north of the Rio Grande mouth is marked by very shallow water, wide tidal flats, lunettes, islands made of beach ridges, and lesser features. The number and variety of islands in the lagoon is remarkable. The lunettes (clay dunes) are made primarily of quartz sand and coarse silt. They are common 5-10 m high, irregular in shape, and steep sided. They were deposited from wind transport and did not migrate. Those that are islands in the lagoon predate present position of sea level. Islands made of beach ridges were built from the lagoon side. Photoanalysis, field work, and granulometry all show that this sand was not moved into these ridges by Gulf of Mexico waves. Trenches in 12 beach ridges showed horizontal bedding but neither low-angle nor steep cross-bedding (quite unlike swash-built beach ridges). The ridges were built by wind-tide lag effects, not from the swash. Therefore, these beach ridges are a new type, in addition to swash-built, eolian, and storm-surge ridges. Growth of the ridges appears to be completed.

  18. Ridges and scarps in the equatorial belt of Mars

    USGS Publications Warehouse

    Lucchitta, B.K.; Klockenbrink, J.L.

    1981-01-01

    The morphology and distribution of ridges and scarps on Mars in the ?? 30?? latitude belt were investigated. Two distinct types of ridges were recognized. The first is long and linear, resembling mare ridges on the Moon; it occurs mostly in plains areas. The other is composed of short, anastomosing segments and occurs mostly in ancient cratered terrain and intervening plateaus. Where ridges are eroded, landscape configurations suggest that they are located along regional structures. The age of ridges is uncertain, but some are as young as the latest documented volcanic activity on Mars. The origins of ridges are probably diverse-they may result from wrinkling due to compression or from buckling due to settling over subsurface structures. The similar morphologic expressions of ridge types of various origins may be related to a similar deformation mechanism caused by two main factors: (1) most ridges are developed in thick layers of competent material and (2) ridges formed under stresses near a free surface. ?? 1981 D. Reidel Publishing Co.

  19. An analysis of ridge axis gravity roughness and spreading rate

    NASA Technical Reports Server (NTRS)

    Small, Christopher; Sandwell, David T.

    1992-01-01

    Fast and slow spreading ridges have radically different morphologic and gravimetric characteristics. In this study, altimeter measurements from the Geosat Exact Repeat Mission are used to investigate spreading rate dependence of the ridge axis gravity field. Gravity roughness provides an estimate of the amplitude of the gravity anomaly and is robust to small errors in the location of the ridge axis. Gravity roughness as a weighted root mean square of the vertical deflection at 438 ridge crossings on the mid-ocean ridge system is computed. Ridge axis gravity anomalies show a decrease in amplitude with increasing spreading rate up to an intermediate rate of about 60-80 mm/yr and almost no change at higher rates; overall the roughness decreases by a factor of 10 between the lowest and highest rates. In addition to the amplitude decrease, the range of roughness values observed at a given spreading rate shows a similar order of magnitude decrease with transition between 60 and 80 mm/yr. The transition of ridge axis gravity is most apparent at three relatively unexplored locations on the Southeast Indian Ridge and the Pacific-Antarctic Rise; on these intermediate rate ridges the transition occurs abruptly across transform faults.

  20. Mantle plume capture, anchoring and outflow during ridge interaction

    NASA Astrophysics Data System (ADS)

    Gibson, S. A.; Richards, M. A.; Geist, D.

    2015-12-01

    Geochemical and geophysical studies have shown that >40% of the world's mantle plumes are currently interacting with the global ridge system and such interactions may continue for up to 180 Myr[1]. At sites of plume-ridge interaction up to 1400 km of the spreading centre is influenced by dispersed plume material but there are few constraints on how and where the ridge-ward transfer of deep-sourced material occurs, and also how it is sustained over long time intervals. Galápagos is an archetypal example of an off-axis plume and sheds important light on these mechanisms. The Galápagos plume stem is located ~200 km south of the spreading axis and its head influences 1000 km of the ridge. Nevertheless, the site of enriched basalts, greatest crustal thickness and elevated topography on the ridge, together with active volcanism in the archipelago, correlate with a narrow zone (~150 km) of low-velocity, high-temperature mantle that connects the plume stem and ridge at depths of ~100 km[2]. The enriched ridge basalts contain a greater amount of partially-dehydrated, recycled oceanic crust than basalts elsewhere on the spreading axis, or indeed basalts erupted in the region between the plume stem and ridge. The presence of these relatively volatile-rich ridge basalts requires flow of plume material below the peridotite solidus (i.e.>80 km). We propose a 2-stage model for the development and sustainment of a confined zone of deep ridge-ward plume flow. This involves initial on-axis capture and establishment of a sub-ridge channel of plume flow. Subsequent anchoring of the plume stem to a contact point on the ridge during axis migration results in confined ridge-ward flow of plume material via a deep network of melt channels embedded in the normal spreading and advection of the plume head[2]. Importantly, sub-ridge flow is maintained. The physical parameters and styles of mantle flow we have defined for Galápagos are less-well known at other sites of plume-ridge

  1. Multiple expressions of plume-ridge interaction at the Galapagos: Volcanic lineaments and ridge jumps

    NASA Astrophysics Data System (ADS)

    Mittelstaedt, E. L.; Soule, S. A.; Harpp, K. S.; Fornari, D. J.

    2011-12-01

    Despite significant evidence for communication between an upwelling mantle plume beneath the Galápagos Archipelago (GA) and the nearby Galápagos Spreading Center (GSC), little is known about the dynamics of the interaction between the ridge and the hotspot. We use new bathymetry, sidescan sonar, magnetic, subbottom seismic, and gravity data from the FLAMINGO cruise (MV1007) to address the mechanism of plume-ridge interaction in the Northern Galápagos Volcanic Province (NGVP), a region centered on the 90° 50'W Galápagos transform fault (GTF). West of the GTF, the Nazca Plate is dominated by numerous seamounts aligned in 3 volcanic lineaments. Volumetrically, the lineaments are composed of ~1500 km3 of erupted lavas. Faulting patterns and seamount elongations suggest that the locations and orientations of the lineaments may be partly controlled by the lithospheric stress field. In contrast, east of the GTF on the Cocos Plate, there is little evidence of constructional volcanism (~69 km3). However, we observe several linear, nearly ridge-parallel, faulted features separating sediment-filled basins, and two large bathymetric highs with up to 1km of relief. Differences in seafloor west and east of the GTF are also observed in the Residual Mantle Bouguer Anomaly (RMBA). On the Nazca Plate, RMBA lows closely contour the volcanic lineaments with minima at the centers of the largest volcanoes along the Wolf-Darwin Lineament. On the Cocos Plate, the RMBA at a given distance from the ridge axis is generally more negative than at similar locations on the Nazca Plate. In addition, two RMBA lows are observed coincident with the observed bathymetric highs, both of which are slightly elongate in a direction sub-parallel to the Eastern GSC, possibly reflecting a period of increased magma flux along a former ridge axis. Magnetic anomalies reveal a complicated history of plate evolution including a series of ridge jumps since ~3 Ma that result in creation of the GTF. We invert

  2. Multiple melting stages and refertilization as indicators for ridge to subduction formation: The New Caledonia ophiolite

    NASA Astrophysics Data System (ADS)

    Ulrich, Marc; Picard, Christian; Guillot, Stéphane; Chauvel, Catherine; Cluzel, Dominique; Meffre, Sébastien

    2010-03-01

    The origin of the New Caledonia ophiolite (South West Pacific), one of the largest in the world, is controversial. This nappe of ultramafic rocks (300 km long, 50 km wide and 2 km thick) is thrust upon a smaller nappe (Poya terrane) composed of basalts from mid-ocean ridges (MORB), back arc basins (BABB) and ocean islands (OIB). This nappe was tectonically accreted from the subducting plate prior and during the obduction of the ultramafic nappe. The bulk of the ophiolite is composed of highly depleted harzburgites (± dunites) with characteristic U-shaped bulk-rock rare-earth element (REE) patterns that are attributed to their formation in a forearc environment. In contrast, the origin of spoon-shaped REE patterns of lherzolites in the northernmost klippes was unclear. Our new major element and REE data on whole rocks, spinel and clinopyroxene establish the abyssal affinity of these lherzolites. Significant LREE enrichment in the lherzolites is best explained by partial melting in a spreading ridge, followed by near in-situ refertilization from deeper mantle melts. Using equilibrium melting equations, we show that melts extracted from these lherzolites are compositionally similar to the MORB of the Poya terrane. This is used to infer that the ultramafic nappe and the mafic Poya terrane represent oceanic lithosphere of a single marginal basin that formed during the late Cretaceous. In contrast, our spinel data highlights the strong forearc affinities of the most depleted harzburgites whose compositions are best modeled by hydrous melting of a source that had previously experienced depletion in a spreading ridge. The New Caledonian boninites probably formed during this second stage of partial melting. The two melting events in the New Caledonia ophiolite record the rapid transition from oceanic accretion to convergence in the South Loyalty Basin during the Late Paleocene, with initiation of a new subduction zone at or near the ridge axis.

  3. Topographic amplification across a taiwanese ridge

    NASA Astrophysics Data System (ADS)

    Rault, Claire; Meunier, Patrick; Burtin, Arnaud; Marc, Odin; Weian Chao, Vvn; Wu, Yih-Min; Hovius, Niels

    2016-04-01

    A line of 6 broadband seismometers have been deployed across a ridge in the Hualien County (Eastern Taiwan) in order to study topographic amplification. Since March 2015, the network has been continuously recording waves incoming from the Taiwanese regional seismicity. The hill is well approximated by a triangular topography of 3600m in length by 900m in height. We present a preliminary analysis performed over a dozen of earthquakes selected from the Seismic Taiwanese catalog (CWBSN). We show that most of the Uphill records exhibit a systematic amplification of seismic waves (peak to peak of particle velocity) in the relevant frequency band [0.5-2Hz]. By contrast, energy within the larger frequency band [6-20Hz] reflects local site effects induced by the soil layer. We report amplification ratios ranging from ranging from 1.2 to 3 and from 1.8 to 4 for P and S waves respectively. We show that amplification processes at the top strongly depend on the parameter α defined as the angle between the azimuth of incoming wave and the azimuth of the ridge divide.

  4. The Oak Ridge Isochronous Cyclotron Refurbishment Project

    SciTech Connect

    Mendez, II, Anthony J; Ball, James B; Dowling, Darryl T; Mosko, Sigmund W; Tatum, B Alan

    2011-01-01

    The Oak Ridge Isochronous Cyclotron (ORIC) has been in operation for nearly fifty years at the Oak Ridge National Laboratory (ORNL). Presently, it serves as the driver accelerator for the ORNL Holifield Radioactive Ion Beam Facility (HRIBF), where radioactive ion beams are produced using the Isotope Separation Online (ISOL) technique for post-acceleration by the 25URC tandem electrostatic accelerator. Operability and reliability of ORIC are critical issues for the success of HRIBF and have presented increasingly difficult operational challenges for the facility in recent years. In February 2010, a trim coil failure rendered ORIC inoperable for several months. This presented HRIBF with the opportunity to undertake various repairs and maintenance upgrades aimed at restoring the full functionality of ORIC and improving the reliability to a level better than what had been typical over the previous decade. In this paper, we present details of these efforts, including the replacement of the entire trim coil set and measurements of their radial field profile. Comparison of measurements and operating tune parameters with setup code predictions will also be presented.

  5. [Comparative study of N, P output and eutrophication risk in runoff water in cross ridge and longitudinal ridge].

    PubMed

    Yu, Xing-Xiu; Ma, Qian; Liu, Qian-Jin; Lü, Guo-An

    2011-02-01

    Field in-situ rainfall simulation tests with two rainfall intensities (40 mm x h(-1) and 70 mm x h(-1)), which were conducted at typical sloping cropland in Yimeng mountainous area, were designed to analyze the output characteristics of dissolved inorganic nitrogen, Inorganic-N (NO3(-)-N, NH4(+) -N) and dissolved phosphorus (DP) in runoff water, as well as to compare the eutrophication risk in this water by calculating three ratios of Inorganic-N/DP, NO3(-) -N/DP, and NH4(+)-N/DP, respectively, in cross ridge and longitudinal ridge tillage methods. Results showed that, under the same rainfall intensity, the DP level in runoff water was higher in cross ridge than longitudinal ridge, while the change of different Inorganic-N level between the two tillage methods were not consistent. Cross ridge could effectively reduce runoff and the output rate of Inorganic-N and DP when compared to the longitudinal ridge tillage, which would be more outstanding with the increases of rainfall intensities. The losses of Inorganic-N and DP in runoff water were 43% and 5% less, respectively, in cross ridge than longitudinal ridge at the 40 mm x h(-1) rainfall intensity, and were 68% and 55%, respectively, at 70 mm x h(-1). The higher Inorganic-N/DP and NO3(-) -N/DP ratios suggest that runoff water from either cross ridge or longitudinal ridge tillage have a certain eutrophication risk, which present an increasing trend during the precipitation-runoff process. Compared with longitudinal ridge, cross ridge can not only hinder the increasing trend of eutrophication risk, but also can significantly lower it, and thus effectively reduce the effect of sloping cropland runoff on the eutrophication processes of receiving waters.

  6. US Department of Energy Oak Ridge Operations Environmental Management Public Involvement Plan for the Oak Ridge Reservation

    SciTech Connect

    1996-03-01

    This document was prepared in accordance with CERCLA requirements for writing community relations plans. It includes information on how the DOE Oak Ridge Operations Office prepares and executes Environmental Management Community relations activities. It is divided into three sections: the public involvement plan, public involvement in Oak Ridge, and public involvement in 1995. Four appendices are also included: environmental management in Oak Ridge; community and regional overview; key laws, agreements, and policy; and principal contacts.

  7. Comparison of buried sand ridges and regressive sand ridges on the outer shelf of the East China Sea

    NASA Astrophysics Data System (ADS)

    Wu, Ziyin; Jin, Xianglong; Zhou, Jieqiong; Zhao, Dineng; Shang, Jihong; Li, Shoujun; Cao, Zhenyi; Liang, Yuyang

    2016-07-01

    Based on multi-beam echo soundings and high-resolution single-channel seismic profiles, linear sand ridges in U14 and U2 on the East China Sea (ECS) shelf are identified and compared in detail. Linear sand ridges in U14 are buried sand ridges, which are 90 m below the seafloor. It is presumed that these buried sand ridges belong to the transgressive systems tract (TST) formed 320-200 ka ago and that their top interface is the maximal flooding surface (MFS). Linear sand ridges in U2 are regressive sand ridges. It is presumed that these buried sand ridges belong to the TST of the last glacial maximum (LGM) and that their top interface is the MFS of the LGM. Four sub-stage sand ridges of U2 are discerned from the high-resolution single-channel seismic profile and four strikes of regressive sand ridges are distinguished from the submarine topographic map based on the multi-beam echo soundings. These multi-stage and multi-strike linear sand ridges are the response of, and evidence for, the evolution of submarine topography with respect to sea-level fluctuations since the LGM. Although the difference in the age of formation between U14 and U2 is 200 ka and their sequences are 90 m apart, the general strikes of the sand ridges are similar. This indicates that the basic configuration of tidal waves on the ECS shelf has been stable for the last 200 ka. A basic evolutionary model of the strata of the ECS shelf is proposed, in which sea-level change is the controlling factor. During the sea-level change of about 100 ka, five to six strata are developed and the sand ridges develop in the TST. A similar story of the evolution of paleo-topography on the ECS shelf has been repeated during the last 300 ka.

  8. Determining informative priors for cognitive models.

    PubMed

    Lee, Michael D; Vanpaemel, Wolf

    2017-02-13

    The development of cognitive models involves the creative scientific formalization of assumptions, based on theory, observation, and other relevant information. In the Bayesian approach to implementing, testing, and using cognitive models, assumptions can influence both the likelihood function of the model, usually corresponding to assumptions about psychological processes, and the prior distribution over model parameters, usually corresponding to assumptions about the psychological variables that influence those processes. The specification of the prior is unique to the Bayesian context, but often raises concerns that lead to the use of vague or non-informative priors in cognitive modeling. Sometimes the concerns stem from philosophical objections, but more often practical difficulties with how priors should be determined are the stumbling block. We survey several sources of information that can help to specify priors for cognitive models, discuss some of the methods by which this information can be formalized in a prior distribution, and identify a number of benefits of including informative priors in cognitive modeling. Our discussion is based on three illustrative cognitive models, involving memory retention, categorization, and decision making.

  9. Informative prior distributions for ELISA analyses.

    PubMed

    Klauenberg, Katy; Walzel, Monika; Ebert, Bernd; Elster, Clemens

    2015-07-01

    Immunoassays are capable of measuring very small concentrations of substances in solutions and have an immense range of application. Enzyme-linked immunosorbent assay (ELISA) tests in particular can detect the presence of an infection, of drugs, or hormones (as in the home pregnancy test). Inference of an unknown concentration via ELISA usually involves a non-linear heteroscedastic regression and subsequent prediction, which can be carried out in a Bayesian framework. For such a Bayesian inference, we are developing informative prior distributions based on extensive historical ELISA tests as well as theoretical considerations. One consideration regards the quality of the immunoassay leading to two practical requirements for the applicability of the priors. Simulations show that the additional prior information can lead to inferences which are robust to reasonable perturbations of the model and changes in the design of the data. On real data, the applicability is demonstrated across different laboratories, for different analytes and laboratory equipment as well as for previous and current ELISAs with sigmoid regression function. Consistency checks on real data (similar to cross-validation) underpin the adequacy of the suggested priors. Altogether, the new priors may improve concentration estimation for ELISAs that fulfill certain design conditions, by extending the range of the analyses, decreasing the uncertainty, or giving more robust estimates. Future use of these priors is straightforward because explicit, closed-form expressions are provided. This work encourages development and application of informative, yet general, prior distributions for other types of immunoassays.

  10. Improved Digitization of Lunar Mare Ridges with LROC Derived Products

    NASA Astrophysics Data System (ADS)

    Crowell, J. M.; Robinson, M. S.; Watters, T. R.; Bowman-Cisneros, E.; Enns, A. C.; Lawrence, S.

    2011-12-01

    Lunar wrinkle ridges (mare ridges) are positive-relief structures formed from compressional stress in basin-filling flood basalt deposits [1]. Previous workers have measured wrinkle ridge orientations and lengths to investigate their spatial distribution and infer basin-localized stress fields [2,3]. Although these plots include the most prominent mare ridges and their general trends, they may not have fully captured all of the ridges, particularly the smaller-scale ridges. Using Lunar Reconnaissance Orbiter Wide Angle Camera (WAC) global mosaics and derived topography (100m pixel scale) [4], we systematically remapped wrinkle ridges in Mare Serenitatis. By comparing two WAC mosaics with different lighting geometry, and shaded relief maps made from a WAC digital elevation model (DEM) [5], we observed that some ridge segments and some smaller ridges are not visible in previous structure maps [2,3]. In the past, mapping efforts were limited by a fixed Sun direction [6,7]. For systematic mapping we created three shaded relief maps from the WAC DEM with solar azimuth angles of 0°, 45°, and 90°, and a fourth map was created by combining the three shaded reliefs into one, using a simple averaging scheme. Along with the original WAC mosaic and the WAC DEM, these four datasets were imported into ArcGIS, and the mare ridges of Imbrium, Serenitatis, and Tranquillitatis were digitized from each of the six maps. Since the mare ridges are often divided into many ridge segments [8], each major component was digitized separately, as opposed to the ridge as a whole. This strategy enhanced our ability to analyze the lengths, orientations, and abundances of these ridges. After the initial mapping was completed, the six products were viewed together to identify and resolve discrepancies in order to produce a final wrinkle ridge map. Comparing this new mare ridge map with past lunar tectonic maps, we found that many mare ridges were not recorded in the previous works. It was noted

  11. Crevasse-squeeze ridge corridors: Diagnostic features of late-stage palaeo-ice stream activity

    NASA Astrophysics Data System (ADS)

    Evans, David J. A.; Storrar, Robert D.; Rea, Brice R.

    2016-04-01

    A 200-km-long and 10-km-wide linear assemblage of till-filled geometrical ridges on the bed of the Maskwa palaeo-ice stream of the late Wisconsinan southwest Laurentide Ice Sheet are interpreted as crevasse-squeeze ridges (CSR) developed during internal flow unit reorganization, immediately prior to ice stream shutdown. Ridge orientations are predominantly orientated WNW-ESE, with a subordinate WSW-ENE alignment, both indicative of ice fracture development transverse to former ice stream flow, as indicated by NNE-SSW aligned MSGL. Subglacial till injection into basal and/or full depth, mode I and II crevasses occurred at the approximate centreline of the ice stream, in response to extension and fracturing. Landform preservation indicates that this took place during the final stages of ice streaming, immediately prior to ice stream shutdown. This linear zone of ice fracturing therefore likely represents the narrowing of the fast-flowing trunk, similar to the plug flow identified in some surging valley glaciers. Lateral drag between the final active flow unit and the slower moving ice on either side is likely recorded by the up-ice bending of the CSR limbs. The resulting CSR corridor, here related to an individual ice stream flow unit, constitutes a previously unreported style of crevasse infilling and contrasts with two existing CSR patterns: (1) wide arcuate zones of CSRs related to widespread fracturing within glacier surge lobes; and (2) narrow concentric arcs of CSRs and recessional push moraines related to submarginal till deformation at active temperate glacier lobes.

  12. Martian wrinkle ridge topography: Evidence for subsurface faults from MOLA

    NASA Astrophysics Data System (ADS)

    Golombek, M. P.; Anderson, F. S.; Zuber, M. T.

    2001-10-01

    Mars Orbiter Laser Altimeter (MOLA) topography shows distinct elevation offsets across wrinkle ridges that can be explained simply by subsurface thrust faults. MOLA has provided the first reliable topographic data of wrinkle ridges to test models for their origin; although previous work has shown that wrinkle ridges result from compressional folding and faulting of near-surface units, the role of thrust faulting and its depth penetration have been argued. Topographic profiles across wrinkle ridges in Solis Planum, Lunae Planum, Tempe Terra, Xanthe Terra, Arcadia, Terra Sirenum, Thaumasia Planum, Arabia Terra, Syrtis Major, and Hesperia Planum show characteristic features such as superposed hills, crenulations, and elevation offsets between the plains on either side of the ridge. The characteristic elevation offsets between plains surfaces on either side of the ridges shown by MOLA are easily explained by subsurface thrust faults that underlie the ridges and produce the offset. In Solis Dorsa, wrinkle ridges are 10-20 km wide (well resolved by the 300 m spaced MOLA elevations), have a total relief of 80-250 m, and have elevation offsets of 50-180 m (well above the uncertainty in the MOLA elevations). MOLA topography shows that the plains decrease in elevation toward the southeast and are deformed into folds or arches not visible in images that are parallel to and in between the ridges. The elevations of the plains on either side of the ridges in Solis and Lunae Plana are characteristically down to the southeast and east, respectively, suggesting that faults beneath the wrinkle ridges offset the plains. This offset indicates underlying thrust faults that dip to the northwest and west, respectively, and systematically lower the southeast side of the plains. The observation that the elevation offsets across the ridges are maintained to the next ridge implies that the thrust fault penetrates to depths of tens of kilometers and thus well into the mechanical lithosphere

  13. Carslberg Ridge and Mid-Atlantic Ridge: Slow-spreading Apparent Analogs

    NASA Astrophysics Data System (ADS)

    Rona, P. A.; Murton, B. J.; Bostrom, K.; Widenfalk, L.; Melson, W. G.; O'Hearn, T.; Cronan, D. S.; Jenkins, W. J.

    2005-12-01

    We compare morphology, tectonics, petrology, and hydrothermal activity of a known section of the Mid-Atlantic Ridge (MAR) between the Kane and Atlantis fracture zones (full multi-beam coverage 21N to 31N) to the lesser known Carlsberg Ridge (CR; limited multi-beam coverage plus satellite altimetry). The CR extends from the Owen Fracture Zone (10N) to the Vityaz Fracture Zone (5S) and spreads at half-rates (~1.2-1.8 cm/yr) similar to the MAR: 1) Morphology: Both ridges exhibit distinct segmentation (primarily sinistral) and axial valleys with high floor to crest relief (range 1122-1771 m). Average lengths of segments (CR: 70 km; MAR: 50 km) and crest-to crest width of the axial valley are greater on the CR (40 km) than MAR (23 km). Axial volcanic ridges form the neovolcanic zone on both ridges, typically 2.6 km wide and 213 m high on the CR. Average water depth near segment centers is greater on the MAR (3933 m) than the CR (3564 m). V-shaped patterns oblique to the spreading axis are present on both ridges. 2) Tectonics: Segments on each ridge are predominantly separated by short-offset (<30 km) non-transform discontinuities with longer transform faults generally spaced hundreds of kilometers apart. Bulls-eye Mantle Bouguer Lows (-30 to -50 mgal) are present at centers of spreading segments on both ridges. Metamorphic core complexes of lower crust and upper mantle are present on the MAR section (at fracture zones) and at least at one locality at 58.33E on the CR. 3) Petrology: MORB composition from our 20 stations along the CR fall into the MORB family, with no evidence of hotspot inputs (no excess K or Nb), or extreme fractionation, similar to the MAR section. REE and trace element patterns between 57E and 61E on the CR indicate increasing melt depletion to the northwest, while glasses exhibit a striking systematic increase in MgO (decrease in fractionation) to the northwest and attain among the most primitive composition of any ocean ridge adjacent to the Owen

  14. A Simulation of Pell Grant Awards and Costs Using Prior-Prior Year Financial Data

    ERIC Educational Resources Information Center

    Kelchen, Robert; Jones, Gigi

    2015-01-01

    We examine the likely implications of switching from a prior year (PY) financial aid system, the current practice in which students file the Free Application for Federal Student Aid (FAFSA) using income data from the previous tax year, to prior-prior year (PPY), in which data from two years before enrollment is used. While PPY allows students to…

  15. Alkalic Basalt in Ridge Axis of 53˚E Amagmatic Segment Center, Southwest Indian Ridge

    NASA Astrophysics Data System (ADS)

    Zhou, H.; Wang, J.; Liu, Y.; Ji, F.; Dick, H. J.

    2014-12-01

    Mid-ocean ridge basalt (MORB) is key tracer of composition and process in the mantle. It is interesting to notice that some alkalic basalts occur in amagmatic spreading center of ultraslow spreading ridges, for examples, 9-16˚E of the Southwest Indian ridge (Standish et al., 2008) and Lena Trough of Arctic Ocean (Snow et al., 2011). The latter is interpreted as the result of the pre-existence of continental transform fault or the especially cold thermal structure of ancient continental lithosphere. 53˚E segment, east of the Gallieni transform fault, was discovered as an amagmatic segment (Zhou and Dick, 2013). On both sides of the ridge axis, peridotites with a little gabbro are exposed in an area more than 3200 km2. Basalts exist in the southern portion of 53˚E segment, indicating the transformation from magmatic to amagmatic spreading about 9.4 million years ago. In April of 2014, Leg 4 of the RV Dayang Yihao cruise 30, basaltic glasses was dredged at one location (3500 m water depth) in the ridge axis of 53˚E segment center. It is shown by electric probe analysis that the samples have extremely high sodium content (4.0-4.49 wt% Na­2O ), relative higher potassium content (0.27-0.32 wt% K2O) and silica (50.67-51.87 wt% SiO2), and lower MgO content (5.9-6.4 wt% MgO). Mg-number is 0.55-0.59. It is distinctly different from the N-MORB (2.42-2.68 wt% Na2O, 0.03-0.06 wt% K2O, 48.6-49.6 wt% Si2O, 8.8-9.0 wt% MgO, Mg-numbers 0.63) distributed in the 560-km-long supersegment, west of the Gallieni transform fault, where the active Dragon Flag hydrothermal field was discovered at 49.6˚E in 2007. The reasons for the alkalic basalt in the ridge axis of 53˚E amagmatic segment center, either by low melting degree of garnet stability field, by melting from an ancient subcontinental lithospheric mantle, or by sodium-metasomatism or even other mantle processes or their combination in the deep mantle, are under further studies.

  16. Proportion estimation using prior cluster purities

    NASA Technical Reports Server (NTRS)

    Terrell, G. R. (Principal Investigator)

    1980-01-01

    The prior distribution of CLASSY component purities is studied, and this information incorporated into maximum likelihood crop proportion estimators. The method is tested on Transition Year spring small grain segments.

  17. Pristine MORB mantle from Gakkel Ridge

    NASA Astrophysics Data System (ADS)

    Snow, J. E.; Hellebrand, E.

    2010-12-01

    Fresh mantle rocks (Total ~300Kg) have been recovered from three dredge hauls on Gakkel Ridge. Most of the fresh material (~275 Kg) is from a single dredge haul (PS66-238) from PFS POLARSTERN ARK XX/2 in 2004 (not from the AMORE expedition). The samples from this group comprise extremely fresh protogranular lherzolites that have clearly defined 1-2 cm orange weathering rinds. The weathered material seems to be mostly discoloration along grain boundaries, as bulk weathering (e.g. Snow and Dick, 1995) cannot be detected in bulk analyses. The fresh cores are largely devoid of serpentine that can be identified in hand sample or SEM. The samples show a bimodal grain size distribution and abundant polygonization of olivine, but little stretching of pyroxene grains, suggesting that they have not been subject to intense deformation that has been seen in many mid-ocean ridge peridotites. Currently, 14 of the 208 discrete samples have been studied. The major element compositions of these samples range from relatively fertile spinel lherzolites to moderately depleted cpx-bearing harzburgites, both in their bulk chemistry and in the compositions of major minerals. The average Cr# (Dick and Bullen, 1984) of spinel ranges from 0.15 to 0.28, suggesting 5-12% melt extraction (Hellebrand et al. 2001). Trace elements measured by SIMS and LA-ICPMS reveal metasomatism and refertilization of the LREE. Os isotopes vary from 187Os/188Os of 0.128 to 0.114, revealing an ancient component that can be interpreted either as a fertile ambient mantle with a highly depleted ancient exotic block or as a single mantle domain variably depleted in an ancient melting event (Liu et al., 2008). Bulk Li isotopic data correspond to estimates of the MORB mantle, however mineral separates show significant isotopic heterogeneity that appears to be caused by diffusion caused by Li redistribution during uplift and cooling (Gao et al., accepted). The altered samples have radically different textures. These

  18. 75 FR 9406 - Crescent Ridge LLC; Notice of Filing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Crescent Ridge LLC; Notice of Filing February 23, 2010. Take notice that on February 16, 2010, Crescent Ridge LLC filed a supplement to its February 2, 2010 section 203...

  19. 60 Years of Great Science (Oak Ridge National Laboratory)

    DOE R&D Accomplishments Database

    2003-01-01

    This issue of Oak Ridge National Laboratory Review (vol. 36, issue 1) highlights Oak Ridge National Laboratory's contributions in more than 30 areas of research and related activities during the past 60 years and provides glimpses of current activities that are carrying on this heritage.

  20. 247. Axial Parkway alignment along ridge top. Note the open ...

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

    247. Axial Parkway alignment along ridge top. Note the open vistas to either side of the roadway. These are maintained through vegetation management. The wood guide rail is a primary safety feature. View is to the northeast. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  1. Physiographic constraints on the origin of lunar wrinkle ridges

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Franklin, B. J.

    1987-01-01

    Wrinkle ridges are linear asymmetric topographic highs with considerable morphologic complexity that are commonly found on the lunar maria and the smooth plains of Mars and Mercury. The origin of planetary wrinkle ridges has been a much argued and debated topic. Early ideas suggested that wrinkle ridges resulted from volcanic intrusion and extrusion of high viscosity lavas; these early ideas were countered with suggestions that wrinkle ridges formed from tectonic processes involving folding and faulting. Combined volcanic and tectonic mechanisms have also been suggested. The identification and analysis of a number of morphologically similar structures on the earth has helped in the recent interpretation of wrinkle ridges as thrust faults that deform surface rocks. Nevertheless, there remains the uncertainty of the dominant role of thrusting versus folding in the formation of planetary wrinkle ridges. Presented is a detailed physiographic analysis of lunar wrinkle ridges in an effort to help distinguish the dominant deformation mechanism. Results agree with the findings of the earth analog study and support the hypothesis that wrinkle ridges form from thrust faults that deform surface rocks.

  2. Oak Ridge Reservation Annual Site environmental report summary for 1994

    SciTech Connect

    1995-09-01

    This document presents a summary of the information collected for the Oak Ridge Reservation 1994 site environmental report. Topics discussed include: Oak Ridge Reservation mission; ecology; environmental laws; community participation; environmental restoration; waste management; radiation effects; chemical effects; risk to public; environmental monitoring; and radionuclide migration.

  3. 76 FR 35909 - Temporary Concession Contract for Blue Ridge Parkway

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-20

    ...-OYC] Temporary Concession Contract for Blue Ridge Parkway AGENCY: National Park Service, Interior. ACTION: Notice of proposed award of temporary concession contracts for Blue Ridge Parkway, NC/VA. SUMMARY... award temporary concession contracts for the conduct of certain visitor services within the Blue...

  4. 13. Whetstone Ridge. View of the restaurant and gift shop. ...

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

    13. Whetstone Ridge. View of the restaurant and gift shop. It's board-and-batten construction with a long integral shed porch across the front, a jerkinhead roof and stone chimney are a reflection of the Appalachian Culture the parkway endeavors to interpret. The view is toward the southwest. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  5. Fingerprint Ridge Count: A Polygenic Trait Useful in Classroom Instruction.

    ERIC Educational Resources Information Center

    Mendenhall, Gordon; And Others

    1989-01-01

    Describes the use of the polygenic trait of total fingerprint ridge count in the classroom as a laboratory investigation. Presents information on background of topic, fingerprint patterns which are classified into three major groups, ridge count, the inheritance model, and activities. Includes an example data sheet format for fingerprints. (RT)

  6. Dielectrophoresis device and method having insulating ridges for manipulating particles

    SciTech Connect

    Cummings, Eric B.; Fiechtner, Gregory J.

    2008-03-25

    Embodiments of the present invention provide methods and devices for manipulating particles using dielectrophoresis. Insulating ridges and valleys are used to generate a spatially non-uniform electrical field. Particles may be concentrated, separated, or captured during bulk fluid flow in a channel having insulating ridges and valleys.

  7. Structural Responses to the Chile Ridge Subduction, Southern South America

    NASA Astrophysics Data System (ADS)

    Rodriguez, E. E.; Russo, R. M.; Mocanu, V. I.; Gallego, A.; Murdie, R.; Comte, D.

    2015-12-01

    The Nazca-Antarctic plate boundary, the Chile spreading ridge, subducts beneath South America, forming the northward-migrating Chile Triple Junction (CTJ), now at ~46.5°S, where an actively spreading segment is currently in the Nazca trench. Ridge subduction is associated with diachronously developed variable structure and magmatism of overriding South America. To assess the effects of ridge subduction, we deployed a network of 39 broadband seismometers in southern Chile between 43 - 49°S and 71 - 76°W from Dec. 2004 - Feb. 2007, recording 102 earthquakes suitable for receiver function analyses, i.e., M > 5.9, of various backazimuths, and at epicentral distances of 30 - 90°. The network encompassed onland portions of the current triple junction and ridge subduction, areas to the south of the CTJ where ridge segments subducted during the last 6 m.y., and regions north of the CTJ not yet affected by ridge subduction, allowing the assessment of the effects of ridge subduction on crustal structure of overriding South America. We constructed 551 teleseismic receiver functions to estimate crustal thicknesses, H, and average compressional to shear wave velocity ratios, Vp/Vs = k, using the iterative time deconvolution method of Ligorria and Ammon (1999). H and k were calculated using the grid search method of Zhu and Kanamori (2000). Beneath stations closest to the trench, where the Nazca plate subducts, we found Moho depths between 28 and 55 km, thickening northward. At the locus of current ridge subduction, in the Taitao Pennisula, thinner crust ranges from 27 - 36 km. H is 36-38 km where the Antarctic plate subducts and the Chile ridge recently subducted. The direct effect of the subducting ridge on South America can be seen in H differences between forearc regions that have sustained ridge subduction versus those that have not. South American forearc crust above the subducted Nazca plate is as much as 28 km thicker than forearc crust recently affected by ridge

  8. Revisiting the Ridge-Push Force Using the Lithospheric Geoid

    NASA Astrophysics Data System (ADS)

    Richardson, R. M.; Coblentz, D. D.

    2014-12-01

    The geoid anomaly and driving force associated with the cooling oceanic lithosphere ("ridge push") are both proportional to dipole moment of the density-depth distribution, and allow a reevaluation of the ridge push force using the geoid. The challenge with this approach is to isolate the "lithospheric geoid" from the full geoid signal. Our approach is to use a band-pass spherical harmonic filter on the full geoid (e.g., EGM2008-WGS84, complete to spherical harmonic degree and order 2159) between orders 6 and 80. However, even this "lithospheric geoid" is noisy, and thus we average over 100 profiles evenly spaced along the global ridge system to obtain an average geoid step associated with the mid-ocean ridges. Because the positive ridge geoid signal is largest near the ridge (and to capture fast-spreading ridges), we evaluate symmetrical profiles extending ±45 m.y. about the ridge. We find an average ridge geoid anomaly of 4.5m, which is equivalent to a 10m anomaly for 100 m.y. old oceanic lithosphere. This geoid step corresponds to a ridge push force of ~2.4 x1012N/m for old oceanic lithosphere of 100 m.y., very similar to earlier estimates of ~2.5 x1012N/m based on simple half-space models. This simple half-space model also predicts constant geoid slopes of about 0.15 m/m.y. for cooling oceanic lithosphere. Our observed geoid slopes are consistent with this value for ages up to 40-50 m.y., but drop off to lower values at greater ages. We model this using a plate cooling model (with a thickness of the order of 125km) to fit the observation that the geoid anomaly and ridge driving force only increase slowly for ages greater than 40 m.y. (in contrast to the half-space model where the linear dependence on age holds for all ages). This reduction of the geoid slope results in a 20% decrease in the predicted ridge push force. This decrease is due to the combined effects of treating the oceanic lithosphere as a cooling plate (vs. a half-space), and the loss of geoidal

  9. Evidence for melt channelization in Galapagos plume-ridge interaction

    NASA Astrophysics Data System (ADS)

    Mittal, T.; Richards, M. A.

    2015-12-01

    Many present-day hot spots are located within ~ 1000 km of a mid-ocean ridge, either currently or in the geologic past, leading to frequent interaction between these two magmatic regimes. The consequent plume-ridge interactions provide a unique opportunity to test models for asthenosphere-lithosphere dynamics, with the plume acting as a tracer fluid in the problem, and excess magmatism reflecting otherwise unsampled sub-surface phenomena. Galapagos is an off-ridge hotspot with the mantle plume located ~150-250 km south of the plate boundary. Plume-ridge interaction in Galapagos is expressed by the formation of volcanic lineaments of islands and seamounts - e.g., the Wolf-Darwin lineament (WDL) - providing a direct probe of the plume-ridge interaction process, especially in regards to geochemical data. Although several models have been proposed to explain plume-ridge interaction in Galapagos, none adequately explain the observed characteristics, especially the WDL. In particular, predicted lithospheric fault orientations and melt density considerations appear at odds with observations, suggesting that lithospheric extension is not the primary process for formation of these islands. Other off-ridge hotspots interacting with nearby spreading ridges, such as Reunion and Louisville, also exhibit volcanic lineaments linking the plume and the ridge. Thus these lineament-type features are a common outcome of plume-ridge interaction that are indicative of the underlying physics. We propose that the lineaments are surface expressions of narrow sub-lithospheric melt channels focused towards the spreading ridge. These channels should form naturally due to the reactive infiltration instability in a two-phase flow of magma and solid mantle as demonstrated in two-phase flow simulations (e.g., Katz & Weatherley 2012). For Galapagos, we show that melt channels can persist thermodynamically over sufficient length-scales to link the plume and nearby ridge segments. We also show that

  10. The axial topographic high at intermediate and fast spreading ridges

    NASA Astrophysics Data System (ADS)

    Carbotte, Suzanne M.; MacDonald, Ken C.

    1994-12-01

    An axial topographic high is commonly observed at both fast spreading ridges and some segments of intermediate spreading ridges. At fast rates the axial high is primarily created by the buoyancy of hot rock and magma beneath the rise. As newly formed crust is transported off axis, little vestige of an axial high is observed on the ridge flanks. In contrast, at intermediate rates, a significant component of the positive topography may be a volcanic construction, preserved on the ridge flanks as abyssal hills, which are slit axial volcanoes. We suggest this difference in the nature of the axial high reflects a lithosphere strong enough to support construction of a volcanic crestal ridge at intermediate spreading rates, but only rarely at fast rates. Relict overlap ridges, found within the discordant zones left by overlapping spreading centers, is one class of ridge-flank topography which appears to have a significant volcanic constructional component even at fast spreading ridges. Unlike topography away from these discontinuities, the relief and shape of overlapping spreading centers is preserved as relict ridge tips are rafted onto the ridge flanks. Reduced magma supply at these discontinuities may give rise to an axial lithosphere strong enough to support volcanic construction of overlap ridges. Low axial lithospheric strength may also account for the lack of normal faults within the innermost 1-2 km of fast, and some intermediate, spreading ridges. With a thin/weak brittle layer at the ridge crest, tensile failure will predominate and few normal faults will form. Depths to the axial magma chamber reflector observed in multi-channel seismic data limit the thickness of the brittel layer on axis to less than 1-2 km for much of the East Pacific Rise (EPR). This depth is comparable to depths over which tensile failure within the oceanic crust will predominate, estimated from the Griffith criteria for fracture initiation (approx. 0.5-1.5 km). As the brittle layer

  11. Influence of mid-ocean ridges on Rossby waves

    NASA Technical Reports Server (NTRS)

    Wang, Liping; Koblinsky, C. J.

    1994-01-01

    Influence of mid-ocean ridges on Rossby wave activity is discussed in simple models. Ridges can influence Rossby waves in two ways, topographic scattering to model parameters such as frequency, ridge height, and ridge width in both barotropic and baroclinic models. In the barotropic model, for certain model parameters there is perfect transmission of Rossby waves, while for some other model parameters the transmission is rather weak. In a two-layer model, if the frequency is not low enough, trapping of baroclinic signals around topography will occur. The mid-ocean ridge is generally not as efficient as the eastern boundary in generating barotropic waves except at high frequencies in a barotropic model. It is much more efficient than the eastern boundary generating baroclinic waves when wind forcing has a very large zonal scale, while less efficient when wind forcing has a short zonal scale.

  12. First-order linear tectonovolcanic ridges in oceans

    NASA Astrophysics Data System (ADS)

    Pushcharovsky, Yu. M.

    2011-03-01

    The first-order Line, Hawaiian, Emperor, Pukapuka, Louisville, Ninetyeast, and Chagos-Lackadive tectonovolcanic ridges in the Pacific and Indian oceans are considered. These ridges are combined into the category of demarcation tectonic units separating the largest morphostructural sectors of the oceans. The ridges extend for thousands kilometers and are a few hundred kilometers in width. Their crest zones are crowned by numerous volcanoes. The volcanic rocks are largely basalts with elevated alkalinity. All of the ridges were formed in the Late Cretaceous-Cenozoic; the ages of particular ridges are variable. The dimensions of the demarcation tectonic units allow us to refer them to the processes proceeding in the mantle, including tectonic flow, faulting, and significant strike-slip displacements.

  13. FOSSIL RIDGE WILDERNESS STUDY AREA, COLORADO.

    USGS Publications Warehouse

    DeWitt, Ed; Kluender, Steven E.

    1984-01-01

    The Fossil Ridge Wilderness Study Area, approximately 20 mi northeast of Gunnison in central Colorado, was studied and its mineral-resource potential assessed. Portions of the study area have substantiated resource potential for gold, silver, copper, lead, zinc, molybdenum, uranium, thorium, rare-earth elements, and high-calcium limestone. Much of the area has a probable resource potential for the preceeding commodities as well as for tin. Various other elements are found in anomalous concentrations within the study area, but there is likelihood for their occurrence in amounts sufficient to constitute resources. Exploration, especially for molybdenum, gold, and uranium, has been active in the past and is expected to continue in the future. No potential for fossil fuel resources was identified in this study.

  14. Reactive spreading: Adsorption, ridging and compound formation

    SciTech Connect

    Saiz, E.; Cannon, R.M.; Tomsia, A.P.

    2000-09-11

    Reactive spreading, in which a chemically active element is added to promote wetting of noble metals on nonmetallic materials, is evaluated. Theories for the energetics and kinetics of the necessary steps involved in spreading are outlined and compared to the steps in compound formation that typically accompany reactive wetting. These include: fluid flow, active metal adsorption, including nonequilibrium effects, and triple line ridging. All of these can be faster than compound nucleation under certain conditions. Analysis and assessment of recently reported experiments on metal/ceramic systems lead to a focus on those conditions under which spreading proceeds ahead of the actual formation of a new phase at the interface. This scenario may be more typical than believed, and perhaps the most effective situation leading to enhanced spreading. A rationale for the pervasive variability and hysteresis observed during high temperature wetting also emerges.

  15. Oak Ridge Reservation environmental report for 1989

    SciTech Connect

    Jacobs, V.A.; Wilson, A.R.

    1990-10-01

    The first two volumes of this report are devoted to a presentation of environmental data and supporting narratives for the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) and surrounding environs during 1989. Volume 1 includes all narrative descriptions, summaries, and conclusions and is intended to be a stand-alone'' report for the ORR for the reader who does not want to review in detail all of the 1989 data. Volume 2 includes the detailed data summarized in a format to ensure that all environmental data are represented in the tables. Narratives are not included in Vol. 2. The tables in Vol. 2 are addressed in Vol. 1. For this reason, Vol. 2 cannot be considered a stand-alone report but is intended to be used in conjunction with Vol. 1. 16 figs., 194 tabs.

  16. Oak Ridge Reservation Environmental report for 1990

    SciTech Connect

    Wilson, A.R.

    1991-09-01

    The first two volumes of this report are devoted to a presentation of environmental data and supporting narratives for the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) and surrounding environs during 1990. Volume 1 includes all narrative descriptions, summaries, and conclusions and is intended to be a stand-alone'' report for the ORR for the reader who does not want to review in detail all of the 1990 data. Volume 2 includes the detailed data summarized in a format to ensure that all environmental data are represented in the tables. Narratives are not included in Vol. 2. The tables in Vol. 2 are addressed in Vol. 1. For this reason, Vol. 2 cannot be considered a stand-alone report but is intended to be used in conjunction with Vol. 1.

  17. Source document for waste area groupings at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Osborne, P.L.; Kuhaida, A.J., Jr.

    1996-09-01

    This document serves as a source document for Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and other types of documents developed for and pertaining to Environmental Restoration (ER) Program activities at Oak Ridge National Laboratory (ORNL). It contains descriptions of the (1) regulatory requirements for the ORR ER Program, (2) Oak Ridge Reservation (ORR) ER Program, (3) ORNL site history and characterization, and (4) history and characterization of Waste Area Groupings (WAGS) 1-20. This document was created to save time, effort, and money for persons and organizations drafting documents for the ER Program and to improve consistency in the documents prepared for the program. By eliminating the repetitious use of selected information about the program, this document will help reduce the time and costs associated with producing program documents. By serving as a benchmark for selected information about the ER Program, this reference will help ensure that information presented in future documents is accurate and complete.

  18. Melton Valley Storage Tanks Capacity Increase Project, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1995-04-01

    The US Department of Energy (DOE) proposes to construct and maintain additional storage capacity at Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee, for liquid low-level radioactive waste (LLLW). New capacity would be provided by a facility partitioned into six individual tank vaults containing one 100,000 gallon LLLW storage tank each. The storage tanks would be located within the existing Melton Valley Storage Tank (MVST) facility. This action would require the extension of a potable water line approximately one mile from the High Flux Isotope Reactor (HFIR) area to the proposed site to provide the necessary potable water for the facility including fire protection. Alternatives considered include no-action, cease generation, storage at other ORR storage facilities, source treatment, pretreatment, and storage at other DOE facilities.

  19. Oak Ridge Health Studies phase 1 report, Volume 1: Oak Ridge Phase 1 overview

    SciTech Connect

    Yarbrough, M.I.; Van Cleave, M.L.; Turri, P.; Daniel, J.

    1993-09-01

    In July 1991, the State of Tennessee initiated the Health Studies Agreement with the United States Department of Energy to carry out independent studies of possible adverse health effects in people living in the vicinity of the Oak Ridge Reservation. The health studies focus on those effects that could have resulted or could result from exposures to chemicals and radioactivity released at the Reservation since 1942. The major focus of the first phase was to complete a Dose Reconstruction Feasibility Study. This study was designed to find out if enough data exist about chemical and radionuclide releases from the Oak Ridge Reservation to conduct a second phase. The second phase will lead to estimates of the actual amounts or the ``doses`` of various contaminants received by people as a result of off-site releases. Once the doses of various contaminants have been estimated, scientists and physicians will be better able to evaluate whether adverse health effects could have resulted from the releases.

  20. Ridges swimming in a sea of dust

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    The muted terrain of northern Acidalia Planitia testifies to the fact that the region is heavily mantled with dust. The most interesting features in this image are the small terraces located along the flanks of the ridges and the patterned ground seen at the base of the largest ridge (upper right). These features appear to be classic examples of periglacial landforms and may indicate the presence of shallow subsurface ice.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

    Image information: VIS instrument. Latitude 54.9, Longitude 351 East (9 West). 19 meter/pixel resolution.

  1. Hydrothermal activity at the Arctic mid-ocean ridges

    NASA Astrophysics Data System (ADS)

    Pedersen, Rolf B.; Thorseth, Ingunn H.; Nygård, Tor Eivind; Lilley, Marvin D.; Kelley, Deborah S.

    Over the last 10 years, hydrothermal activity has been shown to be abundant at the ultraslow spreading Arctic Mid-Ocean Ridges (AMOR). Approximately 20 active and extinct vent sites have been located either at the seafloor, as seawater anomalies, or by dredge sampling hydrothermal deposits. Decreasing spreading rates and decreasing influence of the Icelandic hot spot toward the north along the AMOR result in a north-south change from a shallow and magmatically robust to a deep and magmatically starved ridge system. This contrast gives rise to large variability in the ridge geology and in the nature of the associated hydrothermal systems. The known vent sites at the southern part of the ridge system are either low-temperature or white smoker fields. At the deep, northern parts of the ridge system, a large black smoker field has been located, and seawater anomalies and sulfide deposits suggest that black smoker-type venting is common. Several of these fields may be peridotite-hosted. The hydrothermal activity at parts of the AMOR exceeds by a factor of 2 to 3 what would be expected by extrapolating from observations on faster spreading ridges. Higher fracture/fault area relative to the magma volume extracted seems a likely explanation for this. Many of the vent fields at the AMOR are associated with axial volcanic ridges. Strong focusing of magma toward these ridges, deep rifting of the ridges, and subsequent formation of long-lived detachment faults that are rooted below the ridges may be the major geodynamic mechanisms causing the unexpectedly high hydrothermal activity.

  2. Radar and photoclinometric studies of wrinkle ridges on Mars

    USGS Publications Warehouse

    Watters, T.R.; Robinson, M.S.

    1997-01-01

    Earth-based radar altimetry and image derived photoclinometric profiles were analyzed to examine both the long- and short-wavelength topography associated with wrinkle ridges on Mars. Photoclinometrically derived elevation data across wrinkle ridges were evaluated to determine the sensitivity of profiles to two empirical photoclinometric parameters, the horizontal digital number (HDN) and the scattered light value (SLV). The photoclinometric profiles are extremely sensitive to small variations in HDN. The sense of slope of a profile can be completely reversed over a range in HDN of as little as ?? 1. Comparably small variations in the SLV have relatively minor effects on the photoclinometrically derived elevations. The existence of elevation offsets from one side of the ridge to the other, reported in previous photoclinometric studies of martian wrinkles, were not confirmed through photoclinometry. In addition, no evidence of elevation offsets were found in Earth-based radar altimetry profiles across wrinkle ridges. In order to more accurately model wrinkle ridge topography, we controlled photoclinometrically derived elevations with long-wavelength topography obtained from the radar altimetry. The results of this study do not support kinematic models for the origin of planetary wrinkle ridges that involve deeply rooted thrust faults which separate crustal blocks at different elevations. A kinematic model involving buckling of shallow crustal layers into concentric folds that close, leading to the development of thrust faults, is consistent with wrinkle ridge morphology and terrestrial analogs. Recent geophysical studies of terrestrial analogs and the influence of shallow subsurface structures, particularly buried craters, on the localization of many wrinkle ridges on Mars suggest that thrust faults associated with the ridges are confined to the ridged plains material and do not extend into the lithosphere. Copyright 1997 by the American Geophysical Union.

  3. Radar and photoclinometric studies of wrinkle ridges on Mars

    NASA Astrophysics Data System (ADS)

    Watters, Thomas R.; Robinson, Mark S.

    1997-05-01

    Earth-based radar altimetry and image derived photoclinometric profiles were analyzed to examine both the long- and short-wavelength topography associated with wrinkle ridges on Mars. Photoclinometrically derived elevation data across wrinkle ridges were evaluated to determine the sensitivity of profiles to two empirical photoclinometric parameters, the horizontal digital number (HDN) and the scattered light value (SLV). The photoclinometric profiles are extremely sensitive to small variations in HDN. The sense of slope of a profile can be completely reversed over a range in HDN of as little as +/-1. Comparably small variations in the SLV have relatively minor effects on the photoclinometrically derived elevations. The existence of elevation offsets from one side of the ridge to the other, reported in previous photoclinometric studies of martian wrinkles, were not confirmed through photoclinometry. In addition, no evidence of elevation offsets were found in Earth-based radar altimetry profiles across wrinkle ridges. In order to more accurately model wrinkle ridge topography, we controlled photoclinometrically derived elevations with long-wavelength topography obtained from the radar altimetry. The results of this study do not support kinematic models for the origin of planetary wrinkle ridges that involve deeply rooted thrust faults which separate crustal blocks at different elevations. A kinematic model involving buckling of shallow crustal layers into concentric folds that close, leading to the development of thrust faults, is consistent with wrinkle ridge morphology and terrestrial analogs. Recent geophysical studies of terrestrial analogs and the influence of shallow subsurface structures, particularly buried craters, on the localization of many wrinkle ridges on Mars suggest that thrust faults associated with the ridges are confined to the ridged plains material and do not extend into the lithosphere.

  4. Site descriptions of environmental restoration units at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Kuhaida, A.J. Jr.; Parker, A.F.

    1997-02-01

    This report provides summary information on Oak Ridge National Laboratory (ORNL) Environmental Restoration (ER) sites as listed in the Oak Ridge Reservation Federal Facility Agreement (FFA), dated January 1, 1992, Appendix C. The Oak Ridge National Laboratory was built in 1943 as part of the World War II Manhattan Project. The original mission of ORNL was to produce and chemically separate the first gram-quantities of plutonium as part of the national effort to produce the atomic bomb. The current mission of ORNL is to provide applied research and development in support of the U.S. Department of Energy (DOE) programs in nuclear fusion and fission, energy conservation, fossil fuels, and other energy technologies and to perform basic scientific research in selected areas of the physical, life, and environmental sciences. ER is also tasked with clean up or mitigation of environmental impacts resulting from past waste management practices on portions of the approximately 37,000 acres within the Oak Ridge Reservation (ORR). Other installations located within the ORR are the Gaseous Diffusion Plant (K-25) and the Y-12 plant. The remedial action strategy currently integrates state and federal regulations for efficient compliance and approaches for both investigations and remediation efforts on a Waste Area Grouping (WAG) basis. As defined in the ORR FFA Quarterly Report July - September 1995, a WAG is a grouping of potentially contaminated sites based on drainage area and similar waste characteristics. These contaminated sites are further divided into four categories based on existing information concerning whether the data are generated for scoping or remedial investigation (RI) purposes. These areas are as follows: (1) Operable Units (OU); (2) Characterization Areas (CA); (3) Remedial Site Evaluation (RSE) Areas; and (4) Removal Site Evaluation (RmSE) Areas.

  5. Seismic structure of Cocos and Malpelo Volcanic Ridges and implications for hot spot-ridge interaction

    NASA Astrophysics Data System (ADS)

    SallarèS, Valentí; Charvis, Philippe; Flueh, Ernst R.; Bialas, Joerg

    2003-12-01

    The Cocos and Malpelo Volcanic Ridges are blocks of thickened oceanic crust thought to be the result of the interaction between the Galapagos hot spot and the Cocos-Nazca Spreading Center during the last 20 m.y. In this work we investigate the seismic structure of these two aseismic ridges along three wide-angle transects acquired during the Panama basin and Galapagos plume—New Investigations of Intraplate magmatism (PAGANINI)-1999 experiment. A two-dimensional velocity field with the Moho geometry is obtained using joint refraction/reflection travel time tomography, and the uncertainty and robustness of the results are estimated by performing a Monte Carlo-type analysis. Our results show that the maximum crustal thickness along these profiles ranges from ˜16.5 km (southern Cocos) to ˜19 km (northern Cocos and Malpelo). Oceanic layer 2 thickness is quite uniform regardless of total crustal thickness variations; crustal thickening is mainly accommodated by layer 3. These observations are shown to be consistent with gravity data. The variation of layer 3 velocities is similar along all profiles, being lower where crust is thicker. This leads to an overall anticorrelation between crustal thickness and bulk lower crustal velocity. Since this anticorrelation is contrary to crustal thickening resulting from passive upwelling of abnormally hot mantle, it is necessary to consider active upwelling components and/or some compositional heterogeneities in the mantle source. The NW limit of the Malpelo Ridge shows a dramatic crustal thinning and displays high lower crustal velocities and a poorly defined crust-mantle boundary, suggesting that differential motion along the Coiba transform fault probably separated Regina and Malpelo Ridges.

  6. Geological mapping of the Oak Ridge K-25 Site, Oak Ridge, Tennessee

    SciTech Connect

    Lemiszki, P.J.

    1994-01-01

    The Oak Ridge K-25 Site (formerly known as the Oak Ridge Gaseous Diffusion Plant) is located in the southern Appalachian Valley and Ridge province of east Tennessee and overlies an area of folded and faulted Cambrian through Ordovician sedimentary rocks in the footwall of the Whiteoak Mountain fault. Environmental restoration plans for the area require that the geology of the site be well understood because various aspects of the groundwater system are directly influenced by stratigraphic and structural characteristics of the bedrock. This study involved mapping the bedrock geology of an 18-square mile area in and around the plant site. Field mapping focused on: (1) checking the accuracy of previously mapped stratigraphic and fault contacts, (2) dividing the bedrock into distinct stratigraphic units based on field criteria, (3) determining the geometry of map-scale folds and faults, and (4) documenting various aspects of the local fracture system. Besides accomplishing all of the above tasks, results from this study have led to a number of new hypotheses regarding various aspects of the site geology. First, faulting and folding within carbonates of the Chickamauga Supergroup in the plant area has repeated certain rock units, which requires that there be a thrust fault in the subsurface below them. This thrust fault may project to the surface with the Carters Limestone. Second, thrust slices of the Rome Formation that overlie the Chickamauga carbonates may be extremely thin and have a limited aerial extent. Third, part of the Knox Group on McKinney Ridge is folded into an anticline. Evaluating the above hypotheses will require information about the subsurface that can only be acquired through drilling and surface geophysical surveys. The geologic map produced from this study can be used to evaluate the location of coreholes that will more effectively intersect a combination of stratigraphic, structural, and hydrologic targets.

  7. Tiger team assessment of the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    none,

    1990-02-01

    This document contains findings identified during the Tiger Team Compliance Assessment of the Department of Energy's (DOE's) Y-12 Plant in Oak Ridge, Tennessee. The Y-12 Plant Tiger Team Compliance Assessment is comprehensive in scope. It covers the Environmental, Safety, and Health (including Occupational Safety and Health Administration (OSHA) compliance), and Management areas and determines the plant's compliance with applicable federal (including DOE), state, and local regulations and requirements. 4 figs., 12 tabs.

  8. Oak Ridge Reservation Annual Site Environmental Report for 2006

    SciTech Connect

    McMahon, Wayne; Hughes, Joan; Coffey, Mike; Thompson, Sharon

    2007-09-01

    This document is prepared annually to summarize environmental activities, primarily environmental-monitoring activities, on the Oak Ridge Reservation (ORR) and within the ORR surroundings. The document fulfills the requirement of Department of Energy (DOE) Order 23l.IA, 'Environment, Safety and Health Reporting,' for an annual summary of environmental data to characterize environmental performance. The environmental-monitoring criteria are described in DOE Order 450.1, 'Environmental Protection Program.' The results summarized in this report are based on data collected prior to and through 2006. This report is not intended to provide the results of all sampling on the ORR. Additional data collected for other site and regulatory purposes, such as environmental restoration remedial investigation reports, waste management characterization sampling data, and environmental permit compliance data, are presented in other documents that have been prepared in accordance with applicable DOE guidance and/or laws and are referenced herein as appropriate. Corrections to the report for the previous year are found in Appendix A. Environmental monitoring on the ORR consists primarily of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring involves the collection and analysis of samples or measurements of liquid and gaseous effluents at the point of release to the environment; these measurements allow the quantification and official reporting of contaminants, assessment of radiation and chemical exposures to the public, and demonstration of compliance with applicable standards and permit requirements. Environmental surveillance consists of the collection and analysis of environmental samples from the site and its environs; these activities provide direct measurement of contaminant concentrations in air, water, groundwater, soil, foods, biota, and other media. Environmental surveillance data provide information regarding conformity with

  9. An aerial radiological survey of the Oak Ridge Reservation, Oak Ridge, Tennessee. Date of survey: April 1992

    SciTech Connect

    Maurer, R.J.

    1993-04-01

    An aerial radiological survey of the Oak Ridge Reservation (ORR) and surrounding area in Oak Ridge, Tennessee, was conducted during the period March 30 to April 14,1992. The purpose of the survey was to measure and document the terrestrial radiological environment of the Oak Ridge Reservation for use in environmental management programs and emergency response planning. The aerial survey was flown at an altitude of 150 feet (46 meters) along a series of parallel lines 250 feet (76 meters) apart and included X-10 (Oak Ridge National Laboratory), K-25 (former Gaseous Diffusion Plant), Y-12 (Weapons Production Plant), the Freels Bend Area and Oak Ridge Institute for Science and Education, the East Fork Poplar Creek (100-year floodplain extending from K-25 to Y-12), Elza Gate (former uranium ore storage site located in the city of Oak Ridge), Parcel A, the Clinch River (river banks extending from Melton Hill Dam to the city of Kingston), and the CSX Railroad Tracks (extending from Y-12 to the city of Oak Ridge). The survey encompassed approximately 55 square miles (1 41 square kilometers) of the Oak Ridge Reservation and surrounding area.

  10. The Effect of Ridge Expansion on Implant Stability in Narrow Partially Edentulous Ridges - A Preliminary Clinical Study

    PubMed Central

    Shaik, Latheef Saheb; Meka, Sridhar; Chakravarthi, Srinivas Pandi; Kolli, Naga Neelima Devi; Lingamaneni, Krishna Prasad; Avvaru, Susmita; Tiwari, Rahul

    2016-01-01

    Introduction Currently, dental treatments with better aesthetic results and less treatment time is more acceptable by the patients. Inadequate amount of bone for implant placement at functionally and aesthetically most appropriate position is a common problem. Aim To assess the effect of ridge expansion on implant stability in narrow partially edentulous ridges and to evaluate clinically and radiographically the success of dental implants, placed immediately following ridge expansion procedure. Material and Methods Ten participants (nine males, one female, average age - 28 years) with partial edentulism associated with narrow atrophic alveolar ridges with adequate height and willing to participate in the study were included. The ridge expansion was performed using osteotomes and simultaneous implant placement was done. A total of 10 implants were placed. Stability, achieved ridge width and radiographic crestal bone loss were assessed three months post-operatively. Results Three months follow-up revealed stable implants both clinically and radiographically. All 10 implants were surrounded by adequate amount of bone required for successful functional rehabilitation. Conclusion The study reveals that the technique of ridge expansion using osteotomes is successful in horizontal expansion, in cases of atrophic alveolar ridges thus, eliminating the need for more complex treatment as well as reduces the rehabilitation time along with improving the quality of bone support. PMID:27790575

  11. Site descriptions of environmental restoration units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee

    SciTech Connect

    Goddard, P.L.; Legeay, A.J.; Pesce, D.S.; Stanley, A.M.

    1995-11-01

    This report, Site Descriptions of Environmental Restoration Units at the Oak Ridge K-25 Site, Oak Ridge, Tennessee, is being prepared to assimilate information on sites included in the Environmental Restoration (ER) Program of the K-25 Site, one of three major installations on the Oak Ridge Reservation (ORR) built during World War III as part of the Manhattan Project. The information included in this report will be used to establish program priorities so that resources allotted to the K-25 ER Program can be best used to decrease any risk to humans or the environment, and to determine the sequence in which any remedial activities should be conducted. This document will be updated periodically in both paper and Internet versions. Units within this report are described in individual data sheets arranged alphanumerically. Each data sheet includes entries on project status, unit location, dimensions and capacity, dates operated, present function, lifecycle operation, waste characteristics, site status, media of concern, comments, and references. Each data sheet is accompanied by a photograph of the unit, and each unit is located on one of 13 area maps. These areas, along with the sub-area, unit, and sub-unit breakdowns within them, are outlined in Appendix A. Appendix B is a summary of information on remote aerial sensing and its applicability to the ER program.

  12. Microgravity survey of the Oak Ridge K-25 Site, Oak Ridge, Tennessee

    SciTech Connect

    Kaufmann, R.D.

    1996-05-01

    Karst features are known to exist within the carbonate bedrock of the Oak Ridge K-25 Site and may play an important role in groundwater flow and contaminant migration. This report discusses the results of a microgravity survey of the Oak Ridge K-25 Site. The main objective of the survey is to identify areas containing bedrock cavities. Secondary objectives included correlating the observed gravity to the geology and to variations in overburden thickness. The analysis includes 11 profile lines that are oriented perpendicular to the geologic strike and major structures throughout the K-25 Site. The profile lines are modeled in an effort to relate gravity anomalies to karst features such as concentrations of mud-filled cavities. Regolith thickness and density data provided by boreholes constrain the models. Areally distributed points are added to the profile lines to produce a gravity contour map of the site. In addition, data from the K-901 area are combined with data from previous surveys to produce a high resolution map of that site. The K-25 Site is located in an area of folded and faulted sedimentary rocks within the Appalachian Valley and Ridge physiographic province. Paleozoic age rocks of the Rome Formation, Knox Group, and Chickamauga Supergroup underlie the K-25 Site and contain structures that include the Whiteoak Mountain Fault, the K-25 Fault, a syncline, and an anticline. The mapped locations of the rock units and complex structures are currently derived from outcrop and well log analysis.

  13. Modification of mandibular ridge splitting technique for horizontal augmentation of atrophic ridges

    PubMed Central

    Abu Tair, Jawad A.

    2014-01-01

    Purpose: A two stage approach of ridge splitting and lateral expansion in the mandible to achieve enough bone width for the purpose of dental implants is presented. Materials and Methods: A total of 13 consecutive patients with 16 long-span edentulous areas of the mandibular ridge were included in this study and 42 dental implants were inserted. Corticotomy of a rectangular buccal segment was carried out followed by 3 weeks of recovery; the mandibular ridge was stretched laterally, leaving the buccal periosteum attached to the lateralized segment. In this modification, there was no need for the use of grafted foreign materials to fill the defect and neither the use of barrier membranes, since it was treated practically as a fresh extraction site. To prevent the undesirable movement of the lateral plate, a small chip (2-3 mm in diameter) of bone spacer was properly fixed. The dental implants were placed 3-5 months later on. Results: Approximately, 86% of the expanded areas were successful in providing an adequate width to accommodate an implant. The average gain in width was 3.22 ± 0.97 mm. All intended implants were inserted. Prosthetic loading with fixed prosthesis was successfully implemented in all cases. Conclusion: This modified technique is a simple and short procedure with satisfactory results and minimal morbidity. Of note, this approach is devoid of foreign materials usage and has a low rate cost, therefore, should be employed more often. PMID:24987593

  14. Tuning your priors to the world.

    PubMed

    Feldman, Jacob

    2013-01-01

    The idea that perceptual and cognitive systems must incorporate knowledge about the structure of the environment has become a central dogma of cognitive theory. In a Bayesian context, this idea is often realized in terms of "tuning the prior"-widely assumed to mean adjusting prior probabilities so that they match the frequencies of events in the world. This kind of "ecological" tuning has often been held up as an ideal of inference, in fact defining an "ideal observer." But widespread as this viewpoint is, it directly contradicts Bayesian philosophy of probability, which views probabilities as degrees of belief rather than relative frequencies, and explicitly denies that they are objective characteristics of the world. Moreover, tuning the prior to observed environmental frequencies is subject to overfitting, meaning in this context overtuning to the environment, which leads (ironically) to poor performance in future encounters with the same environment. Whenever there is uncertainty about the environment-which there almost always is-an agent's prior should be biased away from ecological relative frequencies and toward simpler and more entropic priors.

  15. Basic tectonic features of the Knipovich Ridge (North Atlantic) and its neotectonic evolution

    NASA Astrophysics Data System (ADS)

    Peive, A. A.; Chamov, N. P.

    2008-01-01

    The geological and geophysical data primarily on the structure of the upper sedimentary sequence of the northern Knipovich Ridge (Norwegian-Greenland Basin) that were obtained during Cruise 24 of the R/V Akademik Nikolai Strakhov are considered. These data indicate that the recent kinematics of the northern Knipovich Ridge is determined by dextral strike-slip displacements along the Molloy Fracture Zone (315° NW). This stress field is superimposed by a system related to rifting and latitudinal opening of rifts belonging to the ridge proper. Thus, the structural elements formed under the effect of two stress fields are combined in this district. Several stages of tectonic movements are definable. The first stage (prior to 500 ka ago) is marked by the dominant normal faults, which are overlain by the lower and upper sedimentary sequences. The second stage (prior to 120-100 ka ago) is characterized by development of normal and reverse faults, which displace the lower sequence and are overlain by the upper sequence. Both younger and older structural features reveal peaks of tectonic activity separated by intermediate quiet periods 50-60 ka long. The stress field of the regional strike-slip faulting is realized in numerous oblique NE-trending normal and normal-strike-slip faults that divide the rift valley and its walls into the segments of different sizes. Their strike (20°-30° NE) is consistent with a system of secondary antithetic sinistral strike-slip faults. The system of depressions located 40 km west of the rift valley axis may be considered a paleorift zone that is conjugated at 78°07' N and 5°20' W with the NW-trending fault marked by the main dextral offset. The stress field that existed at this stage was identical to the recent one. The rift valley axis migrated eastward to its present-day position approximately 2 Ma ago (if the spreading rate of ˜0.7 cm/yr is accepted). The obtained data substantially refine the understanding of the initial breakup of

  16. Site Characterization Plan for decontamination and decommissioning of Buildings 3506 and 3515 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1993-09-01

    Buildings 3506, the Waste Evaporator Facility, and 3515, the Fission Product Pilot Plant, at Oak Ridge National Laboratory (ORNL), are scheduled for decontamination and decommissioning (D&D). This Site Characterization Plan (SCP) presents the strategy and techniques to be used to characterize Buildings 3506/3515 for the purpose of planning D&D activities. The elements of the site characterization for Buildings 3506/3515 are planning and preparation, field investigation, and characterization reporting. Other level of effort activities will include management and oversight, project controls, meetings, and progress reporting. The objective of the site characterization is to determine the nature and extent of radioactive and hazardous materials and other industrial hazards in and around the buildings. This information will be used in subsequent planning to develop a detailed approach for final decommissioning of the facilities: (1) to evaluate decommissioning alternatives and design the most cost-effective D&D approach; (2) to determine the level and type of protection necessary for D&D workers; and (3) to estimate the types and volumes of wastes generated during D&D activities. The current D&D characterization scope includes the entire building, including the foundation and equipment or materials within the building. To estimate potential worker exposure from the soil during D&D, some subfoundation soil sample collection is planned. Buildings 3506/3515 are located in the ORNL main plant area, to the west and east, respectively, of the South Tank Farm. Building 3506 was built in 1949 to house a liquid waste evaporator and was subsequently used for an incinerator experiment. Partial D&D was done prior to abandonment, and most equipment has been removed. Building 3515 was built in 1948 to house fission product separation equipment. In about 1960, all entrances were sealed with concrete block and mortar. Building 3515 is expected to be highly contaminated.

  17. Commissioning of the PRIOR proton microscope

    DOE PAGES

    Varentsov, D.; Antonov, O.; Bakhmutova, A.; ...

    2016-02-18

    Recently, a new high energy proton microscopy facility PRIOR (Proton Microscope for FAIR Facility for Anti-proton and Ion Research) has been designed, constructed, and successfully commissioned at GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt, Germany). As a result of the experiments with 3.5–4.5 GeV proton beams delivered by the heavy ion synchrotron SIS-18 of GSI, 30 μm spatial and 10 ns temporal resolutions of the proton microscope have been demonstrated. A new pulsed power setup for studying properties of matter under extremes has been developed for the dynamic commissioning of the PRIOR facility. This study describes the PRIOR setup as well asmore » the results of the first static and dynamic protonradiography experiments performed at GSI.« less

  18. Structured sparse priors for image classification.

    PubMed

    Srinivas, Umamahesh; Suo, Yuanming; Dao, Minh; Monga, Vishal; Tran, Trac D

    2015-06-01

    Model-based compressive sensing (CS) exploits the structure inherent in sparse signals for the design of better signal recovery algorithms. This information about structure is often captured in the form of a prior on the sparse coefficients, with the Laplacian being the most common such choice (leading to l1 -norm minimization). Recent work has exploited the discriminative capability of sparse representations for image classification by employing class-specific dictionaries in the CS framework. Our contribution is a logical extension of these ideas into structured sparsity for classification. We introduce the notion of discriminative class-specific priors in conjunction with class specific dictionaries, specifically the spike-and-slab prior widely applied in Bayesian sparse regression. Significantly, the proposed framework takes the burden off the demand for abundant training image samples necessary for the success of sparsity-based classification schemes. We demonstrate this practical benefit of our approach in important applications, such as face recognition and object categorization.

  19. Commissioning of the PRIOR proton microscope

    SciTech Connect

    Varentsov, D.; Antonov, O.; Bakhmutova, A.; Barnes, C. W.; Bogdanov, A.; Danly, C. R.; Efimov, S.; Endres, M.; Fertman, A.; Golubev, A. A.; Hoffmann, D. H. H.; Ionita, B.; Kantsyrev, A.; Krasik, Ya. E.; Lang, P. M.; Lomonosov, I.; Mariam, F. G.; Markov, N.; Mintsev, V. B.; Nikolaev, D.; Panyushkin, V.; Rodionova, M.; Schanz, M.; Schoenberg, K.; Semennikov, A.; Shestov, L.; Skachkov, V. S.; Turtikov, V.; Udrea, S.; Vasylyev, O.; Weyrich, K.; Wilde, C.; Zubareva, A.; Merrill, F. E.

    2016-02-18

    Recently, a new high energy proton microscopy facility PRIOR (Proton Microscope for FAIR Facility for Anti-proton and Ion Research) has been designed, constructed, and successfully commissioned at GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt, Germany). As a result of the experiments with 3.5–4.5 GeV proton beams delivered by the heavy ion synchrotron SIS-18 of GSI, 30 μm spatial and 10 ns temporal resolutions of the proton microscope have been demonstrated. A new pulsed power setup for studying properties of matter under extremes has been developed for the dynamic commissioning of the PRIOR facility. This study describes the PRIOR setup as well as the results of the first static and dynamic protonradiography experiments performed at GSI.

  20. Hydrodynamic role of longitudinal ridges in a leatherback turtle swimming

    NASA Astrophysics Data System (ADS)

    Bang, Kyeongtae; Kim, Jooha; Lee, Sang-Im; Choi, Haecheon

    2015-11-01

    The leatherback sea turtle (Dermochelys coriacea), the fastest swimmer and the deepest diver among marine turtles, has five longitudinal ridges on its carapace. These ridges are the most remarkable morphological features distinguished from other marine turtles. To investigate the hydrodynamic role of these ridges in the leatherback turtle swimming, we model a carapace with and without ridges by using three dimensional surface data of a stuffed leatherback turtle in the National Science Museum, Korea. The experiment is conducted in a wind tunnel in the ranges of the real leatherback turtle's Reynolds number (Re) and angle of attack (α). The longitudinal ridges function differently according to the flow condition (i.e. Re and α). At low Re and negative α that represent the swimming condition of hatchlings and juveniles, the ridges significantly decrease the drag by generating streamwise vortices and delaying the main separation. On the other hand, at high Re and positive α that represent the swimming condition of adults, the ridges suppress the laminar separation bubble near the front part by generating streamwise vortices and enhance the lift and lift-to-drag ratio. Supported by the NRF program (2011-0028032).

  1. An ultrasonic linear motor using ridge-mode traveling waves.

    PubMed

    Tominaga, Masahiko; Kaminaga, Ryuta; Friend, James R; Nakamura, Kentaro; Ueha, Sadayuki

    2005-10-01

    A new type of ultrasonic linear motor is presented using traveling waves excited along a ridge atop a substrate. The ridge cross section was designed to permit only the fundamental mode to be excited during operation of the motor, with a Langevin transducer used as the source of vibration in this study. The ridge waveguide was first made of lossy media to avoid reflecting vibration energy back toward the vibration source, forming a traveling wave. A 5-mm-wide, 15-mm-tall rectangular acrylic ridge was used to move a slider placed upon it toward the vibration source, in opposition to the direction of the traveling wave transmitted along the waveguide ridge. Using a low-loss 3 x 6-mm aluminum rectangular ridge combined with a damper clamped onto the far end of the waveguide, similar results were obtained. To obtain bidirectional operation, the damper was replaced with a second Langevin transducer, giving a pair of transducers located perpendicularly to the ends of the ridge and driven with an appropriate phase difference. The moving direction of the slider was reversed by shifting this phase difference by about 180 degrees. With this simple configuration, it may soon be possible to fabricate a linear micromotor system on a silicon substrate or other semiconductor wafer adjacent to other electronic and optoelectronic devices.

  2. Propagating buoyant mantle upwelling on the Reykjanes Ridge

    NASA Astrophysics Data System (ADS)

    Martinez, Fernando; Hey, Richard

    2017-01-01

    Crustal features of the Reykjanes Ridge have been attributed to mantle plume flow radiating outward from the Iceland hotspot. This model requires very rapid mantle upwelling and a "rheological boundary" at the solidus to deflect plume material laterally and prevent extreme melting above the plume stem. Here we propose an alternative explanation in which shallow buoyant mantle upwelling instabilities propagate along axis to form the crustal features of the ridge and flanks. As only the locus of buoyant upwelling propagates this mechanism removes the need for rapid mantle plume flow. Based on new geophysical mapping we show that a persistent sub-axial low viscosity channel supporting buoyant mantle upwelling can explain the current oblique geometry of the ridge as a reestablishment of its original configuration following an abrupt change in opening direction. This mechanism further explains the replacement of ridge-orthogonal crustal segmentation with V-shaped crustal ridges and troughs. Our findings indicate that crustal features of the Reykjanes Ridge and flanks are formed by shallow buoyant mantle instabilities, fundamentally like at other slow spreading ridges, and need not reflect deep mantle plume flow.

  3. Phanerozoic stratigraphy of Northwind Ridge, magnetic anomalies in the Canada Basin, and the geometry and timing of rifting in the Amerasia Basin, Arctic Ocean

    USGS Publications Warehouse

    Grantz, A.; Clark, D.L.; Phillips, R.L.; Srivastava, S.P.; Blome, C.D.; Gray, L.-B.; Haga, H.; Mamet, B.L.; McIntyre, D.J.; McNeil, D.H.; Mickey, M.B.; Mullen, M.W.; Murchey, B.I.; Ross, C.A.; Stevens, C.H.; Silberling, Norman J.; Wall, J.H.; Willard, D.A.

    1998-01-01

    Cores from Northwind Ridge, a high-standing continental fragment in the Chukchi borderland of the oceanic Amerasia basin, Arctic Ocean, contain representatives of every Phanerozoic system except the Silurian and Devonian systems. Cambrian and Ordovician shallow-water marine carbonates in Northwind Ridge are similar to basement rocks beneath the Sverdrup basin of the Canadian Arctic Archipelago. Upper Mississippian(?) to Permian shelf carbonate and spicularite and Triassic turbidite and shelf lutite resemble coeval strata in the Sverdrup basin and the western Arctic Alaska basin (Hanna trough). These resemblances indicate that Triassic and older strata in southern Northwind Ridge were attached to both Arctic Canada and Arctic Alaska prior to the rifting that created the Amerasia basin. Late Jurassic marine lutite in Northwind Ridge was structurally isolated from coeval strata in the Sverdrup and Arctic Alaska basins by rift shoulder and grabens, and is interpreted to be a riftogenic deposit. This lutite may be the oldest deposit in the Canada basin. A cape of late Cenomanian or Turonian rhyodacite air-fall ash that lacks terrigenous material shows that Northwind Ridge was structurally isolated from the adjacent continental margins by earliest Late Cretaceous time. Closing Amerasia basin by conjoining seafloor magnetic anomalies beneath the Canada basin or by uniting the pre-Jurassic strata of Northwind Ridge with kindred sections in the Sverdrup basin and Hanna trough yield simular tectonic reconstructions. Together with the orientation and age of rift-marine structures, these data suggest that: 1) prior to opening of the Amerasia basin, both northern Alaska and continental ridges of the Chukchi borderland were part of North America, 2) the extension that created the Amerasia basin formed rift-margin graben beginning in Early Jurassic time and new oceanic crust probably beginning in Late Jurassic or early Neocomian time. Reconstruction of the Amerasia basin on the

  4. Geophysical Characteristics of the Australian-Antarctic Ridge

    NASA Astrophysics Data System (ADS)

    Kim, S. S.; Lin, J.; Park, S. H.; Choi, H.; Lee, S. M.

    2014-12-01

    Between 2011 and 2013, the Korea Polar Research Institute (KOPRI) conducted three consecutive geologic surveys at the little explored eastern ends of the Australian-Antarctic Ridge (AAR) to characterize the tectonics, geochemistry, and hydrothermal activity of this intermediate spreading system. Using the Korean icebreaker R/V Araon, the multi-disciplinary research team collected bathymetry, gravity, magnetics, and rock and water column samples. In addition, Miniature Autonomous Plume Recorders (MAPRs) were deployed at wax-core rock sampling sites to detect the presence of active hydrothermal vents. Here we present a detailed analysis of a 300-km-long supersegment of the AAR to quantify the spatial variations in ridge morphology and robust axial and off-axis volcanisms. The ridge axis morphology alternates between rift valleys and axial highs within relatively short ridge segments. To obtain a geological proxy for regional variations in magma supply, we calculated residual mantle Bouguer gravity anomalies (RMBA), gravity-derived crustal thickness, and residual topography for seven sub-segments. The results of the analyses revealed that the southern flank of the AAR is associated with shallower seafloor, more negative RMBA, thicker crust, and/or less dense mantle than the conjugate northern flank. Furthermore, this north-south asymmetry becomes more prominent toward the KR1 supersegment of the AAR. The axial topography of the KR1 supersegment exhibits a sharp transition from axial highs at the western end to rift valleys at the eastern end, with regions of axial highs being associated with more magma supply as indicated by more negative RMBA. We also compare and contrast the characteristics of the AAR supersegment with that of other ridges of intermediate spreading rates, including the Juan de Fuca Ridge, Galápagos Spreading Center, and Southeast Indian Ridge west of the Australian-Antarctic Discordance, to investigate the influence of ridge-hotspot interaction on

  5. Characteristics of Hydrothermal Mineralization in Ultraslow Spreading Ridges

    NASA Astrophysics Data System (ADS)

    Zhou, H.; Yang, Q.; Ji, F.; Dick, H. J.

    2014-12-01

    Hydrothermal activity is a major component of the processes that shape the composition and structure of the ocean crust, providing a major pathway for the exchange of heat and elements between the Earth's crust and oceans, and a locus for intense biological activity on the seafloor and underlying crust. In other hand, the structure and composition of hydrothermal systems are the result of complex interactions between heat sources, fluids, wall rocks, tectonic controls and even biological processes. Ultraslow spreading ridges, including the Southwest Indian Ridge, the Gakkel Ridge, are most remarkable end member in plate-boundary structures (Dick et al., 2003), featured with extensive tectonic amagmatic spreading and frequent exposure of peridotite and gabbro. With intensive surveys in last decades, it is suggested that ultraslow ridges are several times more effective than faster-spreading ridges in sustaining hydrothermal activities. This increased efficiency could attributed to deep mining of heat and even exothermic serpentinisation (Baker et al., 2004). Distinct from in faster spreading ridges, one characteristics of hydrothermal mineralization on seafloor in ultraslow spreading ridges, including the active Dragon Flag hydrothermal field at 49.6 degree of the Southwest Indian Ridge, is abundant and pervasive distribution of lower temperature precipitated minerals ( such as Fe-silica or silica, Mn (Fe) oxides, sepiolite, pyrite, marcasite etc. ) in hydrothermal fields. Structures formed by lower temperature activities in active and dead hydrothermal fields are also obviously. High temperature precipitated minerals such as chalcopyrite etc. are rare or very limited in hydrothermal chimneys. Distribution of diverse low temperature hydrothermal activities is consistence with the deep heating mechanisms and hydrothermal circulations in the complex background of ultraslow spreading tectonics. Meanwhile, deeper and larger mineralization at certain locations along the

  6. SRTM Stereo Pair: Wheeler Ridge, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Wheeler Ridge and vicinity, California, is a site of major tectonic activity, both historically and over recent geologic time. The epicenter of the 7.5 magnitude Kern County earthquake occurred here on July 21,1952, and numerous geologic and topographic features indicate rapid geologic processes. The ridge itself (upper-right center) is a geologic fold that is growing out of the southern San Joaquin Valley. A prominent 'wind gap,' now used for passage of the California aquaduct (with the aid of a pumping station), is evidence that the ridge grew faster than tranversing streams could erode down. Nearby abrupt and/or landslid mountain fronts similarly indicate a vigorous tectonic setting here, just north of the San Andreas fault. The Interstate 5 freeway can be seen crossing agricultural fields on the right and entering the very rugged and steep Grapevine Canyon toward the bottom.

    This stereoscopic image was generated by draping a Landsat satellite image over a preliminary Shuttle Radar Topography Mission (SRTM) elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing), or by downloading and printing the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive.

    The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle

  7. Data Sharing Report for the Quantification of Removable Activity in Various Surveillance and Maintenance Facilities at the Oak Ridge National Laboratory Oak Ridge TN

    SciTech Connect

    King, David A.

    2013-12-12

    The U.S. Department of Energy (DOE) Oak Ridge Office of Environmental Management (OR-EM) requested that Oak Ridge Associated Universities (ORAU), working under the Oak Ridge Institute for Science and Education (ORISE) contract, provide technical and independent waste management planning support using American Recovery and Reinvestment Act (ARRA) funds. Specifically, DOE OR-EM requested that ORAU plan and implement a sampling and analysis campaign targeting potential removable radiological contamination that may be transferrable to future personal protective equipment (PPE) and contamination control materials—collectively referred to as PPE throughout the remainder of this report—used in certain URS|CH2M Oak Ridge, LLC (UCOR) Surveillance and Maintenance (S&M) Project facilities at the Oak Ridge National Laboratory (ORNL). Routine surveys in Bldgs. 3001, 3005, 3010, 3028, 3029, 3038, 3042, 3517, 4507, and 7500 continuously generate PPE. The waste is comprised of Tyvek coveralls, gloves, booties, Herculite, and other materials used to prevent worker exposure or the spread of contamination during routine maintenance and monitoring activities. This report describes the effort to collect and quantify removable activity that may be used by the ORNL S&M Project team to develop radiation instrumentation “screening criteria.” Material potentially containing removable activity was collected on smears, including both masselin large-area wipes (LAWs) and standard paper smears, and analyzed for site-related constituents (SRCs) in an analytical laboratory. The screening criteria, if approved, may be used to expedite waste disposition of relatively clean PPE. The ultimate objectives of this effort were to: 1) determine whether screening criteria can be developed for these facilities, and 2) provide process knowledge information for future site planners. The screening criteria, if calculated, must be formally approved by Federal Facility Agreement parties prior to use for

  8. The Oak Ridge Refrigerant Management Program

    NASA Technical Reports Server (NTRS)

    Kevil, Thomas H.

    1995-01-01

    For many years, chlorofluorocarbons (CFC's) have been used by the Department of Energy's (DOE) Oak Ridge Y-12 Plant in air conditioning and process refrigeration systems. However, Title 6 of the Clean Air Act Amendments (CAAA) and Executive Order 12843 (Procurement Requirements and Policies for Federal Agencies for Ozone Depleting Substances) signed by President Clinton require, as policy, that all federal agencies maximize their use of safe, alternate refrigerants and minimize, where economically practical, the use of Class 1 refrigerants. Unfortunately, many government facilities and industrial plants have no plan or strategy in place to make this changeover, even though their air conditioning and process refrigeration equipment may not be sustainable after CFC production ends December 31, 1995. The Y-12 Plant in Oak Ridge, Tennessee, has taken an aggressive approach to complying with the CAAA and is working with private industry and other government agencies to solve tough manufacturing and application problems associated with CFC and hydrochlorofluorocarbon (HCFC) alternatives. Y-12 was the first DOE Defense Program (DP) facility to develop a long-range Stratospheric Ozone Protection Plan for refrigerant management for compliance with the CAAA. It was also the first DOE DP facility to complete detailed engineering studies on retrofitting and replacing all air conditioning and process refrigeration equipment to enable operation with alternate refrigerants. The management plan and engineering studies are models for use by other government agencies, manufacturing plants, and private industry. This presentation identifies some of the hidden pitfalls to be encountered in the accelerated phaseout schedule of CFC's and explains how to overcome and prevent these problems. In addition, it outlines the general issues that must be considered when addressing the phase-out of ozone depleting substances and gives some 'lessons learned' by Y-12 from its Refrigerant Management

  9. Physical Volcanology of the Huckleberry Ridge Tuff

    NASA Astrophysics Data System (ADS)

    Wilson, C. J.

    2009-12-01

    The 2.06 Ma Huckleberry Ridge Tuff, product of the oldest and largest (ca. 2500 cubic km) of the three caldera-forming eruptions from the Yellowstone system, consists of three major ignimbrite units (A, B, C) with underlying and intervening fall deposits. Despite intense welding, and subsequent significant faulting and erosion, the broad characteristics of the deposits provide valuable insights into the eruption dynamics. Field evidence shows unambiguously that the eruption was spasmodic and prolonged, in addition to complexities previously recognised in vent locations and eruptive compositions by R.L. Christiansen (US Geological Survey Professional Paper 729-G, 2001). The initial fall activity, although plinian in dispersal, was not exceptionally powerful or unusual in any respect, and gives no obvious hints of the scale of what was to follow. This initial fall activity was also prolonged, possibly over months, during which time intrafall reworking occurred at several stages. Ignimbrite unit A is much the largest in volume, and represents most of the thickness of tuff southwest of the caldera, including the rheomorphic tuff of Big Bend Ridge previously mapped as B. Units A and B are separated by weeks or more, based on cooling breaks, and units B and C separated by years or more, based on breaks in cooling and degassing histories. The fall deposit separating ignimbrite units B and C also was erupted spasmodically. Vent-derived lithics in the ignimbrite units are generally mm to cm across, and no coarse lithic-rich facies have been found in units A or B to indicate close proximity to caldera margins. There is also a diversity of juvenile ejecta: red-brown scoria, coarsely porphyritic dense juvenile clasts and their granophyric equivalents, and rhyolitic pumices of a great variety of textures and crystal contents. The overall tuff represents the product of three large and many other small events daisy-chained together and prolonged over a period of probably years to

  10. Solar cell with doped groove regions separated by ridges

    DOEpatents

    Molesa, Steven Edward; Pass, Thomas; Kraft, Steve

    2017-01-31

    Solar cells with doped groove regions separated by ridges and methods of fabricating solar cells are described. In an example, a solar cell includes a substrate having a surface with a plurality of grooves and ridges. A first doped region of a first conductivity type is disposed in a first of the grooves. A second doped region of a second conductivity type, opposite the first conductivity type, is disposed in a second of the grooves. The first and second grooves are separated by one of the ridges.

  11. Reducing geometric dilution of precision using ridge regression signal processing

    NASA Astrophysics Data System (ADS)

    Kelly, R. J.

    The authors propose a method for reducing the effects of GDOP (geometric dilution of precision) in position-fix navigation systems. The idea is to incorporate ridge regression into the aircraft navigation signal processor. MSE (mean square error) performance of an ordinary LMS (least mean square) signal processor was compared with one using ridge regression. Computer simulations confirmed the theory that variance inflation caused by GDOP can be measurably reduced by the ridge regression algorithm. The technique is applicable not only to DME/DME (distance measuring equipment) and GPS but applies also to any position-fix navigation aid, e.g. Loran-C, Omega, and JTIDS relative navigation.

  12. Migration of mid-ocean-ridge volcanic segments

    USGS Publications Warehouse

    Schouten, Hans; Dick, H.J.B.; Klitgord, Kim D.

    1987-01-01

    The propagation of small-offset volcanic spreading-centre segments along mid-ocean ridge crests may reflect absolute motion of the plate boundary relative to the underlying mesospheric frame. Such a relationship could be caused by a purely vertical flow of the mantle under spreading centres and would have value in constraining past plate motions from non-transform trends generated during along-ridge propagation and in linking the major-element variability of oceanic crust and upper mantle to the bulk composition and temperatures of mantle ascending under mid-ocean ridges. ?? 1987 Nature Publishing Group.

  13. Prior knowledge driven Granger causality analysis on gene regulatory network discovery

    SciTech Connect

    Yao, Shun; Yoo, Shinjae; Yu, Dantong

    2015-08-28

    Our study focuses on discovering gene regulatory networks from time series gene expression data using the Granger causality (GC) model. However, the number of available time points (T) usually is much smaller than the number of target genes (n) in biological datasets. The widely applied pairwise GC model (PGC) and other regularization strategies can lead to a significant number of false identifications when n>>T. In this study, we proposed a new method, viz., CGC-2SPR (CGC using two-step prior Ridge regularization) to resolve the problem by incorporating prior biological knowledge about a target gene data set. In our simulation experiments, the propose new methodology CGC-2SPR showed significant performance improvement in terms of accuracy over other widely used GC modeling (PGC, Ridge and Lasso) and MI-based (MRNET and ARACNE) methods. In addition, we applied CGC-2SPR to a real biological dataset, i.e., the yeast metabolic cycle, and discovered more true positive edges with CGC-2SPR than with the other existing methods. In our research, we noticed a “ 1+1>2” effect when we combined prior knowledge and gene expression data to discover regulatory networks. Based on causality networks, we made a functional prediction that the Abm1 gene (its functions previously were unknown) might be related to the yeast’s responses to different levels of glucose. In conclusion, our research improves causality modeling by combining heterogeneous knowledge, which is well aligned with the future direction in system biology. Furthermore, we proposed a method of Monte Carlo significance estimation (MCSE) to calculate the edge significances which provide statistical meanings to the discovered causality networks. All of our data and source codes will be available under the link https://bitbucket.org/dtyu/granger-causality/wiki/Home.

  14. Prior knowledge driven Granger causality analysis on gene regulatory network discovery

    DOE PAGES

    Yao, Shun; Yoo, Shinjae; Yu, Dantong

    2015-08-28

    Our study focuses on discovering gene regulatory networks from time series gene expression data using the Granger causality (GC) model. However, the number of available time points (T) usually is much smaller than the number of target genes (n) in biological datasets. The widely applied pairwise GC model (PGC) and other regularization strategies can lead to a significant number of false identifications when n>>T. In this study, we proposed a new method, viz., CGC-2SPR (CGC using two-step prior Ridge regularization) to resolve the problem by incorporating prior biological knowledge about a target gene data set. In our simulation experiments, themore » propose new methodology CGC-2SPR showed significant performance improvement in terms of accuracy over other widely used GC modeling (PGC, Ridge and Lasso) and MI-based (MRNET and ARACNE) methods. In addition, we applied CGC-2SPR to a real biological dataset, i.e., the yeast metabolic cycle, and discovered more true positive edges with CGC-2SPR than with the other existing methods. In our research, we noticed a “ 1+1>2” effect when we combined prior knowledge and gene expression data to discover regulatory networks. Based on causality networks, we made a functional prediction that the Abm1 gene (its functions previously were unknown) might be related to the yeast’s responses to different levels of glucose. In conclusion, our research improves causality modeling by combining heterogeneous knowledge, which is well aligned with the future direction in system biology. Furthermore, we proposed a method of Monte Carlo significance estimation (MCSE) to calculate the edge significances which provide statistical meanings to the discovered causality networks. All of our data and source codes will be available under the link https://bitbucket.org/dtyu/granger-causality/wiki/Home.« less

  15. 7 CFR 550.27 - Prior approvals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the scope or the objective of the project or program (even if there is no associated budget revision... Regulations of the Department of Agriculture (Continued) AGRICULTURAL RESEARCH SERVICE, DEPARTMENT OF... Program Management § 550.27 Prior approvals. (a) The budget is the financial expression of the project...

  16. Tuning Your Priors to the World

    PubMed Central

    Feldman, Jacob

    2013-01-01

    The idea that perceptual and cognitive systems must incorporate knowledge about the structure of the environment has become a central dogma of cognitive theory. In a Bayesian context, this idea is often realized in terms of “tuning the prior”—widely assumed to mean adjusting prior probabilities so that they match the frequencies of events in the world. This kind of “ecological” tuning has often been held up as an ideal of inference, in fact defining an “ideal observer.” But widespread as this viewpoint is, it directly contradicts Bayesian philosophy of probability, which views probabilities as degrees of belief rather than relative frequencies, and explicitly denies that they are objective characteristics of the world. Moreover, tuning the prior to observed environmental frequencies is subject to overfitting, meaning in this context overtuning to the environment, which leads (ironically) to poor performance in future encounters with the same environment. Whenever there is uncertainty about the environment—which there almost always is—an agent's prior should be biased away from ecological relative frequencies and toward simpler and more entropic priors. PMID:23335572

  17. Augmenting system reliability analyses with observation priors

    SciTech Connect

    Lawrence, Earl; Anderson-cook, Christine

    2009-01-01

    Occasionally, a system may fail a test without an obvious component being at fault. Instead, experts may know that at least one of a set of components has failed, but there is uncertainty about which members in the set were the actual failures. When no further information is available, this missing data may be imputed using standard data augmentation (DA). This process is already used in the current implementation of the JMP complex-system reliability modeling codes. In some cases when this situation arises, there may be some supplemental information about the nature of the failure that suggests which subset of components are more likely to have failed. the behavior of the system during the failure may make certain components more likely candidates, and lead the engineering experts to have certain prior beliefs about what occurred. In this case, it is still known that at least one of a set of components failed, but the experts have some idea that certain failure scenarios are more likely than others. This white paper addresses this situation by modifying the imputation process of data augmentation through the use of an observation prior. This prior is specific to particular observations, and a given outcome which is repeated several times could potentially have different observation priors associated with each occurrence.

  18. 21 CFR 181.5 - Prior sanctions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... use of the ingredient, in order to prevent the adulteration of food in violation of section 402 of the... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Prior sanctions. 181.5 Section 181.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  19. 21 CFR 181.5 - Prior sanctions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... use of the ingredient, in order to prevent the adulteration of food in violation of section 402 of the... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Prior sanctions. 181.5 Section 181.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  20. 21 CFR 181.5 - Prior sanctions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... use of the ingredient, in order to prevent the adulteration of food in violation of section 402 of the... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Prior sanctions. 181.5 Section 181.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  1. 21 CFR 181.5 - Prior sanctions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... use of the ingredient, in order to prevent the adulteration of food in violation of section 402 of the... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Prior sanctions. 181.5 Section 181.5 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR...

  2. Prior Learning Assessment: Outcomes and Characteristics.

    ERIC Educational Resources Information Center

    White, Barbara

    1995-01-01

    Describes the Ontario college system's Prior Learning Assessment program for adult learners, focusing on outcomes and characteristics of students completing the process at Seneca College from April 1994 to February 1995. Indicates that of 77 participants, 46 were female, the mean age was 31, and 81% passed the process successfully. (BCY)

  3. Understanding the Complexities of Prior Knowledge

    ERIC Educational Resources Information Center

    Soiferman, L. Karen

    2014-01-01

    The purpose of the study was to gain an understanding of the kinds of prior knowledge students bring with them from high school as it relates to the conventions of writing that they are expected to follow in ARTS 1110 Introduction to University. The research questions were "Can first-year students taking the Arts 1110 Introduction to…

  4. Accrediting Prior Learning at a Distance.

    ERIC Educational Resources Information Center

    Butterworth, Christine; Edwards, Richard

    1993-01-01

    Discusses the Assessment of Prior Learning (APL) and describes a pilot project at the Open University (United Kingdom) that introduced credit for APL in one course. Steps in the assessment process are outlined, including constructing a student portfolio; and workload, staff development, and costs are considered. (LRW)

  5. Visual Treatment for Different Prior Knowledge.

    ERIC Educational Resources Information Center

    Chanlin, Lih-Juan

    1999-01-01

    Describes a study of college students that was conducted to examine the effectiveness of integrating different computerized visual-presentation strategies in learning different contents; the effect of identical presentation strategies on students possessing different levels of prior knowledge; and whether the use of different visual strategies…

  6. Student Models for Prior Knowledge Estimation

    ERIC Educational Resources Information Center

    Nižnan, Juraj; Pelánek, Radek; Rihák, Jirí

    2015-01-01

    Intelligent behavior of adaptive educational systems is based on student models. Most research in student modeling focuses on student learning (acquisition of skills). We focus on prior knowledge, which gets much less attention in modeling and yet can be highly varied and have important consequences for the use of educational systems. We describe…

  7. 42 CFR 438.806 - Prior approval.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Prior approval. 438.806 Section 438.806 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...) For subsequent years, the amount is increased by the percentage increase in the consumer price...

  8. Oak Ridge Reservation environmental report for 1990

    SciTech Connect

    Wilson, A.R.

    1991-09-01

    The purpose of this report is to provide information to the public about the impact of the US Department of Energy's (DOE's) facilities located on the Oak Ridge Reservation (ORR) on the public and the environment. It describes the environmental surveillance and monitoring activities conducted at and around the DOE facilities operated by Martin Marietta Energy Systems, Inc. Preparation and publication of this report is in accordance with DOE Order 5400.1. The order specifies a publication deadline of June of the following year for each calendar year of data. The primary objective of this report is to summarize all information collected for the previous calendar year regarding effluent monitoring, environmental surveillance, and estimates of radiation and chemical dose to the surrounding population. When multiple years of information are available for a program, trends are also evaluated. The first seven sections of Volume 1 of this report address this objective. The last three sections of Volume 1 provide information on solid waste management, special environmental studies, and quality assurance programs.

  9. Ridge push engine of plate tectonics

    NASA Astrophysics Data System (ADS)

    Swedan, N. H.

    2015-07-01

    Convection of the upper mantle drives the tectonic plates. This convection is a thermodynamic cycle that exchanges heat and mechanical work between mantle and tectonic plates. Thermodynamics and observations indicate that the energy of the geological activities resulting from plate tectonics is equal to the latent heat of melting, calculated at mantle's pressure, of the new ocean crust regenerated at midocean ridges. This energy varies with the temperature of ocean floor, which is correlated with surface temperature. The main objective of this manuscript is to demonstrate that plate tectonics is a thermodynamic engine and can be calculated as such. Unlike existing tectonic models, the thermodynamic model is very sensitive to variations of the temperature of ocean floor, which is correlated with surface temperature. Therefore, the observed increase of geological activities can be projected with surface temperature rise. Other objectives of the manuscript are to calculate the force that drives the tectonic plates, estimate the energy released, and validate the calculations based on experiments and observations. In addition to the scientific merit of projecting the geological activities, a good projection can have a broader impact at the societal and economical levels. Investment and insurance related decisions are affected by climate change, and our ability to project the geological activities is of paramount importance for the economy and public safety. This work can thus provide tools to assess the risks and hazards associated with the trend of geological activities with surface temperature rise.

  10. 3D gravity modelling reveals off-axis crustal thickness variations along the western Gakkel Ridge (Arctic Ocean)

    NASA Astrophysics Data System (ADS)

    Schmidt-Aursch, Mechita C.; Jokat, Wilfried

    2016-11-01

    Near-orthogonal ultra-slow (13.3 mm yr- 1 to 6.5 mm yr- 1) sea floor spreading in the absence of large transform faults make the Arctic Gakkel Ridge ideally suited for the study of magmatic processes. To enable this, we generated a three-dimensional gravity model of crustal thickness over the ridge and parts of the adjacent Nansen and Amundsen basins west of 65° E. The model shows that oceanic crust accreted prior to chrons C5/C6 is generally very thin (1-3 km). Magnetic anomalies over this thin crust are highly variable both parallel and perpendicular to the ridge axis. This is the result of amagmatic or weakly volcanic spreading that started with the opening of the basins 56 Ma ago. The separation of Greenland from Svalbard at chron C5/C6 led to the inflow of North Atlantic mantle into the western Eurasia Basin leading to a change in the mantle convection system and the establishment of a magmatic dichotomy along the Gakkel Ridge. Robust magmatism was established in the Western Volcanic Zone (6° 30‧ W-3° 30‧ E), leading to creation of a 6.6 km thick igneous crust, characterized by a strong positive axial magnetic anomaly, numerous volcanic cones, and widespread thick mid-ocean ridge basalts. The transition to the neighbouring Sparsely Magmatic (3° 30‧ E-29° E) and Eastern Volcanic (29° E-85° E) zones is sharp. Peridotites cover the central valley and the inner rift flanks, the central magnetic anomaly vanishes and crustal thickness decreases to 1-4 km. Transverse basement ridges, extending for as much as 100 km into the adjacent basins, intersect the central valley. Although partly of tectonic origin, the transverse ridges are also an expression of long-living magmatic centres, as revealed by increased magnetic anomaly intensities and local thickening of the crust to values as great as 5.9 km.

  11. Data Sharing Report Characterization of Isotope Row Facilities Oak Ridge National Laboratory Oak Ridge TN

    SciTech Connect

    Weaver, Phyllis C.

    2013-12-12

    The U.S. Department of Energy (DOE) Oak Ridge Office of Environmental Management (EM-OR) requested that Oak Ridge Associated Universities (ORAU), working under the Oak Ridge Institute for Science and Education (ORISE) contract, provide technical and independent waste management planning support using funds provided by the American Recovery and Reinvestment Act (ARRA). Specifically, DOE EM-OR requested ORAU to plan and implement a survey approach, focused on characterizing the Isotope Row Facilities located at the Oak Ridge National Laboratory (ORNL) for future determination of an appropriate disposition pathway for building debris and systems, should the buildings be demolished. The characterization effort was designed to identify and quantify radiological and chemical contamination associated with building structures and process systems. The Isotope Row Facilities discussed in this report include Bldgs. 3030, 3031, 3032, 3033, 3033A, 3034, 3036, 3093, and 3118, and are located in the northeast quadrant of the main ORNL campus area, between Hillside and Central Avenues. Construction of the isotope production facilities was initiated in the late 1940s, with the exception of Bldgs. 3033A and 3118, which were enclosed in the early 1960s. The Isotope Row facilities were intended for the purpose of light industrial use for the processing, assemblage, and storage of radionuclides used for a variety of applications (ORNL 1952 and ORAU 2013). The Isotope Row Facilities provided laboratory and support services as part of the Isotopes Production and Distribution Program until 1989 when DOE mandated their shutdown (ORNL 1990). These facilities performed diverse research and developmental experiments in support of isotopes production. As a result of the many years of operations, various projects, and final cessation of operations, production was followed by inclusion into the surveillance and maintenance (S&M) project for eventual decontamination and decommissioning (D&D). The

  12. Geophysical Surveys of a Known Karst Feature, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    Carpenter, P.J.; Carr, B.J.; Doll, W.E.; Kaufmann, R.D.; Nyquist, J.E.

    1999-11-14

    Geophysical data were acquired at a site on the Oak Ridge Reservation, Tennessee to determine the characteristics of a mud-filled void and to evaluate the effectiveness of a suite of geophysical methods at the site. Methods that were used included microgravity, electrical resistivity, and seismic refraction. Both microgravity and resistivity were able to detect the void as well as overlying structural features. The seismic data provide bedrock depth control for the other two methods, and show other effects that are caused by the void.

  13. Oak Ridge Dose Reconstruction Project Summary Report; Reports of the Oak Ridge Dose Reconstruction, Vol. 7

    SciTech Connect

    Thomas E. Widner; et. al.

    1999-07-01

    In the early 1990s, concern about the Oak Ridge Reservation's past releases of contaminants to the environment prompted Tennessee's public health officials to pursue an in-depth study of potential off-site health effects at Oak Ridge. This study, the Oak Ridge dose reconstruction, was supported by an agreement between the U.S. Department of Energy (DOE) and the State of Tennessee, and was overseen by a 12-member panel of individuals appointed by Tennessee's Commissioner of Health. The panel requested that the principal investigator for the project prepare the following report, ''Oak Ridge Dose Reconstruction Project Summary Report,'' to serve the following purposes: (1) summarize in a single, less technical report, the methods and results of the various investigations that comprised the Phase II of the dose reconstruction; (2) describe the systematic searching of classified and unclassified historical records that was a vital component of the project; and (3) summarize the less detailed, screening-level assessments that were performed to evaluate the potential health significance of a number of materials, such a uranium, whose priority did not require a complete dose reconstruction effort. This report describes each major step of the dose reconstruction study: (1) the review of thousands of historical records to obtain information relating to past operations at each facility; (2) estimation of the quantity and timing of releases of radioiodines from X-10, of mercury from Y-12, of PCB's from all facilities, and of cesium-137 and other radionuclides from White Oak Creek; (3) evaluation of the routes taken by these contaminants through the environment to nearby populations; and (4) estimation of doses and health risks to exposed groups. Calculations found the highest excess cancer risks for a female born in 1952 who drank goat milk; the highest non-cancer health risk was for children in a farm family exposed to PCBs in and near East Fork Poplar Creek. More detailed

  14. Project plan for the Background Soil Characterization Project on the Oak Ridge Reservation, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1992-08-01

    The Background Soil characterization Project (BSCP) will provide background concentration levels of selected metals, organic compounds, and radionuclides in soils from uncontaminated on-site areas at the Oak Ridge Reservation (ORR), and off-site in the western part of Roane County and the eastern part of Anderson County. The BSCP will establish a database, recommend how to use the data for contaminated site assessment, and provide estimates of the potential human health and environmental risks associated with the background level concentrations of potentially hazardous constituents.

  15. INDEPENDENT VERIFICATION OF THE BUILDING 3550 SLAB AT OAK RIDGE NATIONAL LABORATORY OAK RIDGE, TENNESSEE

    SciTech Connect

    Weaver, Phyllis C.

    2012-05-08

    The Oak Ridge Institute for Science and Education (ORISE) has completed the independent verification survey of the Building 3550 Slab. The results of this effort are provided. The objective of this verification survey is to provide independent review and field assessment of remediation actions conducted by Safety and Ecology Corporation (SEC) to document that the final radiological condition of the slab meets the release guidelines. Verification survey activities on the Building 3550 Slab that included scans, measurements, and the collection of smears. Scans for alpha, alpha plus beta, and gamma activity identified several areas that were investigated.

  16. Mesoscopic structural analysis of bedrock exposures at the Oak Ridge K-25 Site, Oak Ridge, Tennessee

    SciTech Connect

    Lemiszki, P.J.

    1995-07-01

    This document presents the detailed study of outcrop of mesoscopic structures during the geologic mapping completed in 1992-1993. The purpose of this study was to document the geometry and style of outcrop scale structures, such as fractures and faults and relate them to map scale structures present in the Oak Ridge K-25 Area. This report was prepared to document site characterization data collected during the scoping phase investigations in accordance with the requirements of the Comprehensive Environmental Response, Compensation, and Liability Act.

  17. Geophysical Surveys of a Known Karst Feature, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    Doll, W.E.; Nyquist, J.E.; Carpenter, P.J.; Kaufmann, R.D.; Carr, B.J.

    1998-12-01

    Geophysical data were acquired at a site on the Oak Ridge Reservation, Tennessee to determine the characteristics of a mud-filled void and to evaluate the effectiveness of a suite of geophysical methods at the site. Methods that were used included microgravity, electrical resistivity, and seismic refraction. Both microgravity and resistivity were able to detect the void as well as overlying structural features. The seismic data provide bedrock depth control for the other two methods, and show other effects that are caused by the void.

  18. The Equatorial Ridges of Pan and Atlas: Terminal Accretionary Ornaments?

    NASA Astrophysics Data System (ADS)

    Charnoz, Sébastien; Brahic, André; Thomas, Peter C.; Porco, Carolyn C.

    2007-12-01

    In the outer regions of Saturn’s main rings, strong tidal forces balance gravitational accretion processes. Thus, unusual phenomena may be expected there. The Cassini spacecraft has recently revealed the strange “flying saucer” shape of two small satellites, Pan and Atlas, located in this region, showing prominent equatorial ridges. The accretion of ring particles onto the equatorial surfaces of already-formed bodies embedded in the rings may explain the formation of the ridges. This ridge formation process is in good agreement with detailed Cassini images showing differences between rough polar and smooth equatorial terrains. We propose that Pan and Atlas ridges are kilometers-thick “ring-particle piles” formed after the satellites themselves and after the flattening of the rings but before the complete depletion of ring material from their surroundings.

  19. Marathon Oil Company – Circle Ridge NPDES Permit

    EPA Pesticide Factsheets

    Under NPDES permit WY-0000949, the Marathon Oil Company – Circle Ridge is authorized to discharge from its wastewater treatment facility located in Fremont County, Wyoming to a tributary to Coal Draw.

  20. Basaltic Pressure Ridges: Formation and Relationship to Flow Emplacement

    NASA Technical Reports Server (NTRS)

    Theilig, E.

    1985-01-01

    Pressure ridges and pressure plateau are common but not ubiquitous surface features on terrestrial basaltic lava flows and may reflect a specific flow emplacement mechanism. Many of the ridges are large enough to be detected on high-resolution orbital images; therefore, understanding these features could provide a means for interpreting volcanic flows on the mechanism of pressure ridge formation and how their formation relates to flow emplacement. Results from detailed field studies indicate that pressure ridges and plateaus: (1) are emplaced as individual flow lobes, (2) can be composed of primary or secondary material, (3) are dependent on duration and volume of activity within the flow unit, (4) are penecontemporaneous in formation, and (5) are indicative of slowly advancing flows with numerous flow lobes continuously forming and overriding each other.

  1. Criticality emergency planning at Oak Ridge National Laboratory

    SciTech Connect

    Green, J.H.; Cain, G.C.

    1983-01-01

    A plan to protect personnel and control the spread of contamination in the event of a radiation accident at Oak Ridge National Laboratory (ORNL) is outlined. Procedures and personnel are presented. (ACK)

  2. Coupled ridge waveguide distributed feedback quantum cascade laser arrays

    SciTech Connect

    Liu, Ying-Hui; Zhang, Jin-Chuan Yan, Fang-Liang; Liu, Feng-Qi Zhuo, Ning; Wang, Li-Jun; Liu, Jun-Qi; Wang, Zhan-Guo

    2015-04-06

    A coupled ridge waveguide quantum cascade laser (QCL) array consisting of fifteen elements with parallel integration was presented. In-phase fundamental mode operation in each element is secured by both the index-guided nature of the ridge and delicate loss management by properly designed geometries of the ridges and interspaces. Single-lobe lateral far-field with a nearly diffraction limited beam pattern was obtained. By incorporating a one-dimensional buried distributed feedback grating, the in-phase-operating coupled ridge waveguide QCL design provides an efficient solution to obtaining high output power and stable single longitudinal mode emission. The simplicity of this structure and fabrication process makes this approach attractive to many practical applications.

  3. 23. Detail, ridge cresting and finial elements, deteriorated slates, southeast ...

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

    23. Detail, ridge cresting and finial elements, deteriorated slates, southeast roof slope, view to northwest from lift-bed truck, 135mm lens. - Southern Pacific Depot, 559 El Camino Real, San Carlos, San Mateo County, CA

  4. Wrinkle ridges, stress domains, and kinematics of venusian plains

    NASA Technical Reports Server (NTRS)

    Mcgill, George E.

    1993-01-01

    Wrinkle ridges are nearly ubiquitous landforms on the plains of Venus. By analogy with similar structures on other planets, venusian wrinkle ridges are inferred to trend normal to the direction of maximum principal compression in the crust, an inference that is verified by geometrical relationships with positive and negative relief features on Venus. Because plains are the dominant terrain on Venus, wrinkle ridges provide an excellent opportunity to determine the orientations of shallow crustal principal stress trajectories over most of the planet. In most places there are two or more sets of wrinkle ridges, and commonly one of these persists over a large area, defining a regional stress domain. Intersection relationships indicate that these domains differ in age.

  5. Ridges on Europa: Origin by Incremental Ice-Wedging

    NASA Technical Reports Server (NTRS)

    Melosh, H. J.; Turtle, E. P.

    2004-01-01

    The surface of Europa is covered by ridges that display a variety of morphologies . The most common type is characterized by a double ridge divided by an axial trough. These ridges are, in general, narrow (typically only a few km across) and remarkably linear. They are up to a few hundred meters high and the inner and outer slopes appear to stand at the angle of repose . A number of diverse mechanisms have been proposed to explain the formation of these ubiquitous features , although none can fully account for all of their observed characteristics. We propose a different formation theory in which accumulation of material within cracks that open during the extensional phase of the tidal cycle prevents complete closure of the cracks during the tidal cycle s compressional phase. This accumulation deforms the surrounding ice and, in time, results in the growth of a landform remarkably similar to the ridges observed on Europa.

  6. 3. ENVIRONMENT, FROM SOUTH, SHOWING RIVER ROAD RIDGE CARRYING CASSELMAN ...

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

    3. ENVIRONMENT, FROM SOUTH, SHOWING RIVER ROAD RIDGE CARRYING CASSELMAN RIVER ROAD OVER CASSELMAN RIVER - River Road Bridge, Crossing Casselman River on Casselman River Road, Grantsville, Garrett County, MD

  7. Science and Technology at Oak Ridge National Laboratory

    ScienceCinema

    Mason, Thomas

    2016-07-12

    ORNL Director Thom Mason explains the groundbreaking work in neutron sciences, supercomputing, clean energy, advanced materials, nuclear research, and global security taking place at the Department of Energy's Office of Science laboratory in Oak Ridge, Tenn.

  8. Science and Technology at Oak Ridge National Laboratory

    SciTech Connect

    Mason, Thomas

    2012-11-01

    ORNL Director Thom Mason explains the groundbreaking work in neutron sciences, supercomputing, clean energy, advanced materials, nuclear research, and global security taking place at the Department of Energy's Office of Science laboratory in Oak Ridge, Tenn.

  9. Geoid anomalies over Gorringe Ridge, North Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Souriau, A.

    1984-04-01

    The geoid anomalies over Gorringe Ridge, a very prominent high in the topography north of the Azores-Gibraltar plate boundary, have been deduced from Seasat alimetric data, and an interpretation of these anomalies together with the gravity anomalies is attempted. The geoid anomalies generated by the topographic high alone with the serpentinite density nearly fit the observed geoid anomalies, so that the structure must be either out of isostatic equilibrium or compensated at great depth. It is shown that a model in isostatic equilibrium with a small negative density contrast extending to 60 km depth or more explains both the gravity and geoid anomalies and is compatible with the deep seismicity north of Gorringe Ridge. Previous nonisostatic models, one involving an uplift of the upper mantle beneath the ridge, one describing a nascent subduction zone, and another involving flexure of the elastic part of the lithosphere due to the ridge loading, are discussed.

  10. 60 years of great science [Oak Ridge National Laboratory

    SciTech Connect

    2003-01-01

    This issue highlights Oak Ridge National Laboratory's contributions in more than 30 areas of research and related activities during the past 60 years and provides glimpses of current activities that are carrying on this heritage.

  11. Nested Paleozoic "successor" basins in the southern Appalachian Blue Ridge

    NASA Astrophysics Data System (ADS)

    Tull, James F.; Groszos, Mark S.

    1990-11-01

    Field studies in the southern Appalachian Blue Ridge and its southwest extension, the Talladega belt, indicate that in at least three regions, polydeformed and metamorphosed turbidite-dominated sequences unconformably overlie rifted-margin continental-terrace wedge clastic rocks and overlying carbonate-platform deposits. These sequences are (1) the Talladega Group (in the Talladega belt), (2) the Walden Creek Group (along the west flank of the Blue Ridge), and (3) the Mineral Bluff Formation (within the core of the Blue Ridge). Paleontologic evidence indicates that the Talladega and Walden Creek Groups are in part as young as Silurian-Devonian. The presence of these anomalously young sequences unconformably above the trailing-margin stratigraphy in the Blue Ridge brings into question conventional ideas of the timing and nature of the tectonic evolution of the ancient continental margin.

  12. View of Lake Sabrina Dam upstream face from ridge showing ...

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

    View of Lake Sabrina Dam upstream face from ridge showing spillway at lower right of photo, view southwest - Bishop Creek Hydroelectric System, Plant 2, Lake Sabrina Dam, Bishop Creek, Bishop, Inyo County, CA

  13. Nested Paleozoic successor basins in the southern Appalachian Blue Ridge

    SciTech Connect

    Tull, J.F.; Groszos, M.S. )

    1990-11-01

    Field studies in the southern Appalachian Blue Ridge and its southwest extension, the Talladega belt, indicate that in at least three regions, polydeformed and metamorphosed turbidite-dominated sequences unconformably overlie rifted-margin continental-terrace wedge clastic rocks and overlying carbonate-platform deposits. These sequences are (1) the Talladega Group (in the Talladega belt), (2) the Walden Creek Group (along the west flank of the Blue Ridge), and (3) the Mineral Bluff Formation (within the core of the Blue Ridge). Paleontologic evidence indicates that the Talladega and Walden Creek Groups are in part as young as Silurian-Devonian. The presence of these anomalously young sequences unconformably above the trailing-margin stratigraphy in the Blue Ridge brings into question conventional ideas of the timing and nature of the tectonic evolution of the ancient continental margin.

  14. Mid-ocean ridge dynamics - Observations and theory

    SciTech Connect

    Phipps morgan, J. )

    1991-01-01

    Recent observational and theoretical investigations of midocean-ridge extension and its relation to melting, magmatic, deformation, and hydrothermal processes are discussed in a critical review of U.S. research from the period 1987-1990. Topics examined include segmentation, along-axis crustal variations and gravity, axial crust and lithosphere structure and seismics, ophiolite studies, and the interaction of ridge and continental rift studies. Consideration is given to theoretical models of axial topography; mantle flow, melting, and melt migration; mantle rheology and flow beneath a midoceanic ridge; upwelling structure and segmentation; the role of the lithosphere in shaping ridge segmentation; thermal stress and the origin of fracture zones; and hydrothermal cooling. A comprehensive bibliography is provided.

  15. The outcome of intraoral onlay block bone grafts on alveolar ridge augmentations: A systematic review

    PubMed Central

    Aloy-Prósper, Amparo; Peñarrocha-Oltra, David; Peñarrocha-Diago, Maria A.

    2015-01-01

    Aim: The purpose of this study was to systematically review clinical studies examining the survival and success rates of implants placed with intraoral onlay autogenous bone grafts to answer the following question: do ridge augmentations procedures with intraoral onlay block bone grafts in conjunction with or prior to implant placement influence implant outcome when compared with a control group (guided bone regeneration, alveolar distraction, native bone or short dental implants.)? Material and Method: An electronic data banks and hand searching were used to find relevant articles on vertical and lateral augmentation procedures performed with intraoral onlay block bone grafts for dental implant therapy published up to October 2013. Publications in English, on human subjects, with a controlled study design –involving at least one group with defects treated with intraoral onlay block bone grafts, more than five patients and a minimum follow-up of 12 months after prosthetic loading were included. Two reviewers extracted the data. Results: A total of 6 studies met the inclusion criteria: 4 studies on horizontal augmentation and 2 studies on vertical augmentation. Intraoperative complications were not reported. Most common postsurgical complications included mainly mucosal dehiscences (4 studies), bone graft or membrane exposures (3 studies), complete failures of block grafts (2 studies) and neurosensory alterations (4 studies). For lateral augmentation procedures, implant survival rates ranged from 96.9% to 100%, while for vertical augmentation they ranged from 89.5% to 100%. None article studied the soft tissues healing. Conclusions: Survival and success rates of implants placed in horizontally and vertically resorbed edentulous ridges reconstructed with block bone grafts are similar to those of implants placed in native bone, in distracted sites or with guided bone regeneration. More surgical challenges and morbidity arise from vertical augmentations, thus short

  16. Unraveling the unusual morphology of the Cretaceous Dirck Hartog extinct mid-ocean ridge

    NASA Astrophysics Data System (ADS)

    Watson, S. J.; Whittaker, J. M.; Halpin, J.; Williams, S.; Milan, L. A.; Daczko, N. R.; Wyman, D. A.

    2015-12-01

    The Perth Abyssal Plain (PAP), offshore southwest Australia formed during Mesozoic East Gondwana breakup and Kerguelen plume activity. This study combines petrographic and geochemical data from the first samples ever to be dredged from the flanks of the Dirck Hartog Ridge (DHR), a prominent linear bathymetric feature in the central PAP, with new bathymetric profiles across the PAP to better constrain the formation of the early Indian Ocean floor. The DHR exhibits high relief and distinctive asymmetry that is unusual compared to most active or extinct spreading centres and likely results from compression and deformation of the recently extinct DHR during changes in relative motion of the Indian plate (110 - 100 Ma). Exhumation of gabbros in the southern DHR and an increase in seafloor roughness towards the centre of the PAP, likely result from a half spreading rate decrease from 35 mm/yr (based on magnetic reversals) to 24 mm/yr at ~114 Ma. The results support a slowdown of spreading prior to full cessation at ~102 Ma. The composition of basaltic samples varies along the DHR: from sub-alkaline dolerites with incompatible element concentrations most similar to depleted-to-normal mid-ocean ridge basalts in the south, to alkali basalts similar to ocean island basalts in the north. Therefore, magma sources and degrees of partial melting varied in space and time, a result supporting the interpretation that the DHR is an extinct spreading ridge rather than a pseudofault. The enriched alkali basalt signatures may be attributed to melting of a heterogeneous mantle or to the influence of the Kerguelen plume over distances greater than 1000 km. The results demonstrate the significance of regional tectonic plate motions on the formation and deformation of young ocean crust, and provide insight into the unique DHR morphology.

  17. Mica deposits of the Blue Ridge in North Carolina

    USGS Publications Warehouse

    Lesure, Frank Gardner

    1968-01-01

    Pegmatites in the Blue Ridge of North Carolina are important sources of sheet and scrap mica, feldspar, kaolin, and quartz.  Small amounts of beryl, columbite-tantalite, monazite, samarskite, and uranium minerals also have been produced.  The mica-bearing pegmatites occur in mica and hornblende gneiss and schist throughout the Blue Ridge province but are concentrated in the Spruce Pine and Franklin-Sylva districts.

  18. The Oak Ridge Reservation Annual Site Environmental Report Summary, 2007

    SciTech Connect

    None, None

    2009-02-28

    The Oak Ridge Reservation Annual Site Environmental Report is prepared and published each year to inform the public of the environmental activities that take place on the reservation and in the surrounding areas. It is written to comply with DOE Order 231.1A, Environment, Safety, and Health Reporting. This document has been prepared to present the highlights of the Oak Ridge Reservation Annual Site Environmental Report 2007 in an easy-to-read, summary format.

  19. Ridge Waveguide Structures in Magnesium-Doped Lithium Niobate

    NASA Technical Reports Server (NTRS)

    Himmer, Phillip; Battle, Philip; Suckow, William; Switzer, Greg

    2011-01-01

    This work proposes to establish the feasibility of fabricating isolated ridge waveguides in 5% MgO:LN. Ridge waveguides in MgO:LN will significantly improve power handling and conversion efficiency, increase photonic component integration, and be well suited to spacebased applications. The key innovation in this effort is to combine recently available large, high-photorefractive-damage-threshold, z-cut 5% MgO:LN with novel ridge fabrication techniques to achieve high-optical power, low-cost, high-volume manufacturing of frequency conversion structures. The proposed ridge waveguide structure should maintain the characteristics of the periodically poled bulk substrate, allowing for the efficient frequency conversion typical of waveguides and the high optical damage threshold and long lifetimes typical of the 5% doped bulk substrate. The low cost and large area of 5% MgO:LN wafers, and the improved performance of the proposed ridge waveguide structure, will enhance existing measurement capabilities as well as reduce the resources required to achieve high-performance specifications. The purpose of the ridge waveguides in MgO:LN is to provide platform technology that will improve optical power handling and conversion efficiency compared to existing waveguide technology. The proposed ridge waveguide is produced using standard microfabrication techniques. The approach is enabled by recent advances in inductively coupled plasma etchers and chemical mechanical planarization techniques. In conjunction with wafer bonding, this fabrication methodology can be used to create arbitrarily shaped waveguides allowing complex optical circuits to be engineered in nonlinear optical materials such as magnesium doped lithium niobate. Researchers here have identified NLO (nonlinear optical) ridge waveguide structures as having suitable value to be the leading frequency conversion structures. Its value is based on having the low-cost fabrication necessary to satisfy the challenging pricing

  20. High-Resolution Image of Europa's Ridged Plains

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This spectacular image taken by NASA's Galileo spacecraft camera shows a region of ridged plains on Jupiter's moon Europa. The plains are comprised of many parallel and cross-cutting ridges, commonly in pairs. The majority of the region is of very bright, but darker material is seen primarily in valleys between ridges. Some of the most prominent ridges have dark deposits along their margins and in their central valleys. Some of this dark material probably moved down the flanks of the ridges and has piled up along their bases. The most prominent ridges are about a kilometer in width (less than a mile). In the top right hand corner of the image the end of a dark wide ridge (about 2 kilometers or 1.2 miles across) is visible. Several deep fractures cut through this ridge and continue into the plains. The brightness of the region suggests that frost covers much of Europa's surface. This image looks different from those obtained earlier in Galileo's mission, because this image was taken with the Sun higher in Europa's sky.

    This image was taken on December 16, 1997 at a range of 1,300 kilometers (800 miles) by Galileo's solid state imaging system. North is to the top of the picture, and the Sun illuminates the surface from the upper left. This image, centered at approximately 14 degrees south latitude and 194 degrees west longitude, covers an area approximately 20 kilometers (12 miles) on each side. The resolution is 26 meters (85 feet) per picture element.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://www.jpl.nasa.gov/ galileo.

  1. Characterizing Cratering at the Iapetus Equatorial Ridge using Stereo Topography

    NASA Astrophysics Data System (ADS)

    Persaud, D. M.

    2015-12-01

    Since the arrival of the Cassini probe to the Saturnian system in 2004, the flattened shape and extreme equatorial ridge of the moon Iapetus have posed a number of questions regarding its geophysical evolution. Current models suggest either tidal despinning or a collapsed ring system formed the ridge, with 26Al decay serving as an additional heating mechanism and warm ice or liquid water beneath a thick lithosphere potentially allowing for large-scale topography and deformation to occur (Sandwell and Schubert 2010). Structure at the ridge itself provides further questions in understanding the deformation of Iapetus at its equator. Persaud and Phillips (2014) use stereo topography to present a trend of crater relaxation and crater diameter that suggests a secondary heating event has relaxed younger, smaller craters focused at this region. The extreme slopes along the ridge, however, complicate understanding the order of events that have occurred on Iapetus, including ridge formation, crater relaxation, secondary thermal events, and mass wasting. We use topographic profiles of Iapetus impact craters extracted from digital elevation models (DEMs) constructed with stereo images from the Cassini ISS Instrument to characterize crater complexity and transition diameters versus crater floor geometry, proximity to the equatorial ridge, and relaxation percentage. We then use these results to begin to develop a geometric model of events at the ridge on Iapetus to understand its deformation history. We will present results and discussion of using stereo topography for these analyses. References: Sandwell, D., and G. Schubert. A contraction model for the flattening and equatorial ridge of Iapetus, Icarus 210, 817-822, 2010. Persaud, D.M., and C.B. Phillips. Methods of Estimating Initial Crater Depths on Icy Satellites using Stereo Topography, AGU Fall Meeting 2014, abstract 17043. This work was supported by the 2015 NASA Ames Academy for Space Exploration.

  2. Updated subsurface data base for Bear Creek Valley, Chestnut Ridge, and parts of Bethel Valley on the U.S. Department of Energy Oak Ridge Reservation. Revision 3

    SciTech Connect

    Jones, S.B.; Thompson, B.K.; Field, S.M.

    1995-07-01

    Construction and hydrogeological data for 1,173 boreholes and wells installed through May 1995 at the Oak Ridge Y-12 Plant and in the surrounding vicinity are summarized in this document. This document represents the third revision to Y/TS-881 and is the sixth update of a previous compilation. General data about boreholes and wells included in the data base are survey coordinates, elevations, alternative names and well status. Construction data tabulated include total depth, completion method, borehole diameter, casing and screen materials, filter pack depths, open-hole intervals, and open hole diameters. Hydrogeological data summarized include depth to weathered and fresh bedrock, formations penetrated, sampling history, and whether rock core and geophysical logs were obtained. The tabulations provide a means of determining the amount and quality of data available for a particular borehole or well. Applications of the data include evaluation of the suitability of wells for continued use in groundwater investigations and monitoring studies, site hydrogeological characterization activities, background evaluations of sites prior to initiation of new drilling activities, and hydrogeological review of selected sites prior to the initiation of remedial actions.

  3. 77 FR 24976 - Environmental Impact Statement for the Proposed Wheatgrass Ridge Wind Project, Fort Hall Indian...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-26

    ... Bureau of Indian Affairs Environmental Impact Statement for the Proposed Wheatgrass Ridge Wind Project... on the Environmental Impact Statement (EIS) for the proposed Wheatgrass Ridge Wind Project on the... EIS because the proponent of the Wheatgrass Ridge Wind Project, the Wheatgrass Ridge Wind, LLC.,...

  4. 78 FR 44942 - Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-25

    ... Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation AGENCY: Department of Energy... Site-Specific Advisory Board (EM SSAB), Oak Ridge Reservation. The Federal Advisory Committee Act (Pub... Coordinator, Department of Energy Oak Ridge Operations Office, P.O. Box 2001, EM-90, Oak Ridge, TN...

  5. 77 FR 45345 - Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-31

    ... Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation AGENCY: Department of Energy... Site-Specific Advisory Board (EM SSAB), Oak Ridge Reservation. The Federal Advisory Committee Act (Pub... Oak Ridge Operations Office, P.O. Box 2001, EM-90, Oak Ridge, TN 37831. Phone (865) 241-3315; Fax...

  6. 75 FR 43518 - Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-26

    ... Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation AGENCY: Department of Energy... Site-Specific Advisory Board (EM SSAB), Oak Ridge Reservation. The Federal Advisory Committee Act (Pub..., Department of Energy Oak Ridge Operations Office, P.O. Box 2001, EM-90, Oak Ridge, TN 37831. Phone (865)...

  7. Multi-beam surveys of the Michelson Ridge guyots: Subduction or obduction

    NASA Astrophysics Data System (ADS)

    Christian Smoot, N.

    1983-12-01

    This is the first graphic presentation of the Michelson Ridge in its entirety from a total coverage, multi-beam survey. The ridge splits the Izu and Bonin Trenches, is comprised of four guyots, and is anomalous to the strike of all other ridges heretofore discovered in the Pacific Ocean. The ridge is obducting/offscraping onto the Philippine plate instead of subducting.

  8. Constrained circulation at Endeavour ridge facilitates colonization by vent larvae.

    PubMed

    Thomson, Richard E; Mihály, Steven F; Rabinovich, Alexander B; McDuff, Russell E; Veirs, Scott R; Stahr, Frederick R

    2003-07-31

    Understanding how larvae from extant hydrothermal vent fields colonize neighbouring regions of the mid-ocean ridge system remains a major challenge in oceanic research. Among the factors considered important in the recruitment of deep-sea larvae are metabolic lifespan, the connectivity of the seafloor topography, and the characteristics of the currents. Here we use current velocity measurements from Endeavour ridge to examine the role of topographically constrained circulation on larval transport along-ridge. We show that the dominant tidal and wind-generated currents in the region are strongly attenuated within the rift valley that splits the ridge crest, and that hydrothermal plumes rising from vent fields in the valley drive a steady near-bottom inflow within the valley. Extrapolation of these findings suggests that the suppression of oscillatory currents within rift valleys of mid-ocean ridges shields larvae from cross-axis dispersal into the inhospitable deep ocean. This effect, augmented by plume-driven circulation within rift valleys having active hydrothermal venting, helps retain larvae near their source. Larvae are then exported preferentially down-ridge during regional flow events that intermittently over-ride the currents within the valley.

  9. Alveolar Ridge Split Technique Using Piezosurgery with Specially Designed Tips

    PubMed Central

    Moro, Alessandro; Foresta, Enrico; Falchi, Marco; De Angelis, Paolo; D'Amato, Giuseppe; Pelo, Sandro

    2017-01-01

    The treatment of patients with atrophic ridge who need prosthetic rehabilitation is a common problem in oral and maxillofacial surgery. Among the various techniques introduced for the expansion of alveolar ridges with a horizontal bone deficit is the alveolar ridge split technique. The aim of this article is to give a description of some new tips that have been specifically designed for the treatment of atrophic ridges with transversal bone deficit. A two-step piezosurgical split technique is also described, based on specific osteotomies of the vestibular cortex and the use of a mandibular ramus graft as interpositional graft. A total of 15 patients were treated with the proposed new tips by our department. All the expanded areas were successful in providing an adequate width and height to insert implants according to the prosthetic plan and the proposed tips allowed obtaining the most from the alveolar ridge split technique and piezosurgery. These tips have made alveolar ridge split technique simple, safe, and effective for the treatment of horizontal and vertical bone defects. Furthermore the proposed piezosurgical split technique allows obtaining horizontal and vertical bone augmentation. PMID:28246596

  10. Along ridge variation of the seafloor cooling and subsidence

    NASA Astrophysics Data System (ADS)

    Huang, Po-Ju; Chiao, Ling-Yun

    2013-04-01

    Bathymetry is linearly proportional to the square root of the seafloor age according to decades of observations. It is well explained by the essentially one-dimensional thermal contraction such as that demonstrated in the classical half-space cooling model and the subsequent 2-D modifications such as the plate model, GDH1 model, PSM model etc. However, much less efforts have been undertaken on study of variation of seafloor cooling along the ridge axis. We carefully examine corridors in the spreading direction that avoid seamounts and other some secondary structures, in addition to the sediment correction. We find that subsidence rates vary along major mid-ocean ridges. It would require a range of 400 to -600°C difference if the subsidence rate variations are attributed entirely to sub-ridge mantle temperature anomalies. Pronounced anomalies include the noticeable lows at the equator in the mid-Atlantic ridge and the northern section of East Pacific Rise that might be attributed to the close by continental lithosphere. The eastern section in mid-Indian ridge is also significantly cooler within regions of the Australian-Antarctic Discordance (AAD), which has been attributed to an ancient slab stalled beneath the present-day Southeast Indian Ridge (SEIR). Further researches that take into account of trends of geoid data is underway to make consistent interpretations.

  11. Petrological variability of recent magmatism at Axial Seamount summit, Juan de Fuca Ridge

    NASA Astrophysics Data System (ADS)

    Dreyer, Brian M.; Clague, David A.; Gill, James B.

    2013-10-01

    A combined study of mapping, observational, age constraint, and geochemical data at the summit of Axial Seamount, Juan de Fuca Ridge, has revealed its recent petrological history. Multiple basalt types erupted at the summit in a time sequence. At least three different magma batches have been present beneath the Axial Summit caldera during the last millennium, each with a range in differentiation. The first, prior to 1100 CE, was compositionally diverse, dominantly aphyric T-MORB. The second, from ˜1220 to 1300 CE, was dominantly plagioclase-phyric, more mafic N-MORB erupted mostly in the central portion of the caldera. Since ˜1400 CE, lavas have been more differentiated, and nearly aphyric T-MORB mostly erupted in the caldera's rift zones. Parental magmas vary subtly due to small coupled differences in the degree of melting and sources, but all share a uniform differentiation trend indicating pooling at similar depths. Thus, melts percolate through melt-rich lenses that remain partially isolated in space and/or time. Centennial magmatic timescales at Axial Seamount are similar to those for fast spreading ridge segments. The fluctuation between aphyric and plagioclase-phyric lava likely reflects different pathways or velocities of melt migration.

  12. The National Teacher Enhancement Program (K-8) coordinated by the Oak Ridge National Laboratory

    SciTech Connect

    Richmond, C.R.

    1991-01-01

    Teachers need help, not harassment. So do the establishments in which teachers practice their profession. Community resources must be marshalled to provide help to local schools and teachers. In 1990 the National Science Foundation (NSF) established a unique educational activity named the National Teacher Enhancement Program (NTEP). NSF took advantage of the Department of Energy (DOE) sponsored educational programs and resources at several large DOE contractor labs that had had prior experience with DOE supported teacher enhancement programs. While DOE concentrated on teacher enhancement activities for secondary teachers, the NSF concentrated on teachers from grades K-8. The Oak Ridge National Laboratory (ORNL) is the lead organization for both administering and coordinating the grant. Other participating laboratories are Argonne National Laboratory (ANL), Fermi National Accelerator Laboratory (FERMI), Battelle-Pacific Northwest Laboratory (PNL), Lawrence Livermore Laboratory (LLNL) with some support functions provided by Brookhaven National Laboratory (BNL) and the Oak Ridge Associated Universities (ORAU). The program calls for a three week duration workshop to be conducted at each lab followed by in-service training and other activities during the year. The NSF/NTEP protocol calls for networking among the participating organizations and some of the teachers. An assessment effort is also an integral part of the program. 2 refs.

  13. Influence of prior involvement on employees' ratings.

    PubMed

    Brody, Richard G; Frank, Kimberly E

    2002-02-01

    Surveys show that the majority of firms provide merit pay to outstanding employees. Despite the widespread use of merit pay programs, there is no consensus as to their effectiveness. While some plans have been successful in motivating employees to achieve higher performance, others have caused employees' dissatisfaction and discouragement. One previously unexplored area in the implementation of merit pay systems is the effect of the decision-maker's prior involvement with the employee on the decision to grant merit. The purpose of this paper was to examine whether hiring an employee leads to larger merit allocations despite evidence that the standards for merit were not met. 101 accounting students participated to assess the influence of hiring on subsequent merit allocations. Analysis indicated that prior involvement does bias ensuing merit decisions.

  14. [Medical examination prior to trade school admission].

    PubMed

    Hursidić-Radulović, Azra; Decković-Vukres, Vlasta

    2005-01-01

    Regulation on medical examination prior to apprenticeship is built in the Act on Trades and Crafts. Medical examinations of the students before admission to secondary craft schools have been done regularly since 1993. Between 11,000 and 14,000 students are admitted to secondary craft schools in the Republic of Croatia annually. According to statistics, about 10% of students have obvious health problems, about 5% of students have healt problems which vitally limit their capacity in particular crafts. This statistic refers to about 3% of the examined students. Medical examinations of students prior to admission to craft schools represent a particular sort of health capacity examinations. The paper includes applications for the most freqent trades and crafts, and findings of the craft school admission examinations.

  15. Distance priors from Planck 2015 data

    SciTech Connect

    Huang, Qing-Guo; Wang, Ke; Wang, Sai E-mail: wangke@itp.ac.cn

    2015-12-01

    We update the distance priors by adopting Planck TT,TE,EE+lowP data released in 2015, and our results impose at least 30% tighter constraints than those from Planck TT+lowP. Combining the distance priors with the combination of supernova Union 2.1 compilation of 580 SNe (Union 2.1) and low redshift Baryon Acoustic Oscillation (BAO) data, we constrain the cosmological parameters in the freely binned dark energy (FBDE) and FBDE+Ω{sub k} models respectively, and find that the equations of state of dark energy in both models are consistent with w=−1. Furthermore, we show that the tension with the BAO data at z=2.34 from Lyα forest (LyαF) auto-correlation and Combined LyαF cannot be relaxed in the FBDE and FBDE+Ω{sub k} models.

  16. Image Reconstruction Using Analysis Model Prior

    PubMed Central

    Han, Yu; Du, Huiqian; Lam, Fan; Mei, Wenbo; Fang, Liping

    2016-01-01

    The analysis model has been previously exploited as an alternative to the classical sparse synthesis model for designing image reconstruction methods. Applying a suitable analysis operator on the image of interest yields a cosparse outcome which enables us to reconstruct the image from undersampled data. In this work, we introduce additional prior in the analysis context and theoretically study the uniqueness issues in terms of analysis operators in general position and the specific 2D finite difference operator. We establish bounds on the minimum measurement numbers which are lower than those in cases without using analysis model prior. Based on the idea of iterative cosupport detection (ICD), we develop a novel image reconstruction model and an effective algorithm, achieving significantly better reconstruction performance. Simulation results on synthetic and practical magnetic resonance (MR) images are also shown to illustrate our theoretical claims. PMID:27379171

  17. Inactive tanks remediation program strategy and plans for Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1997-03-01

    This report presents plans and strategies for remediation of the liquid low-level waste (LLLW) tanks that have been removed from service (also known as inactive tanks) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. These plans and strategies will be carried out by the Environmental Restoration Program`s Inactive LLLW Tank Program at ORNL. These tanks are defined as Category D tanks because they are existing tank systems without secondary containment that are removed from service. The approach to remediation of each tank or tank farm must be adapted in response to the specific circumstances of individual tank sites. The approach will be tailored to accommodate feedback on lessons learned from previous tank remediation activities and will not be a rigid step-by-step approach that must be conducted identically for every tank system. However, the approach will follow a multistep decision process. The overall objective of the Inactive Tank Program is to remediate all LLLW tanks that have been removed from service to the extent practicable in accordance with the FFA requirements. The Inactive Tank Program will focus on the remediation of the tank residues (i.e., contents after tank has been emptied) and tank shell. This strategy is discussed in detail in this report.

  18. Inactive tanks remediation program strategy and plans for Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1997-11-01

    This report presents plans and strategies for remediation of the liquid low-level waste (LLLW) tanks that have been removed from service (also known as inactive tanks) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. These plans and strategies will be carried out by the Environmental Restoration Program`s Inactive LLLW Tank Program at ORNL. The approach to remediation of each tank or tank farm must be adapted in response to the specific circumstances of individual tank sites. The approach will be tailored to accommodate feedback on lessons learned from previous tank remediation activities and will not be a rigid step-by-step approach that must be conducted identically for every tank system. However, the approach will follow a multistep decision process. The overall objective of the Inactive Tank Program is to remediate all LLLW tanks that have been removed from service to the extent practicable in accordance with the FFA requirements. The Inactive Tank Program will focus on the remediation of the tank residues and tank shell. This strategy is discussed in detail in this report.

  19. Quality assurance plan for Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1994-01-01

    This Quality Assurance Plan (QAP) is concerned with design and construction (Sect. 2) and characterization and monitoring (Sect. 3). The basis for Sect. 2 is the Quality Assurance Plan for the Design and Construction of Waste Area Grouping 6 Closure at Oak Ridge National Laboratory, Oak Ridge, Tennessee, and the basis for Sect. 3 is the Environmental Restoration Quality Program Plan. Combining the two areas into one plan gives a single, overall document that explains the requirements and from which the individual QAPs and quality assurance project plans can be written. The Waste Area Grouping (WAG) 6 QAP establishes the procedures and requirements to be implemented for control of quality-related activities for the WAG 6 project. Quality Assurance (QA) activities are subject to requirements detailed in the Martin Marietta Energy Systems, Inc. (Energy Systems), QA Program and the Environmental Restoration (ER) QA Program, as well as to other quality requirements. These activities may be performed by Energy Systems organizations, subcontractors to Energy Systems, and architect-engineer (A-E) under prime contract to the US Department of Energy (DOE), or a construction manager under prime contract to DOE. This plan specifies the overall Energy Systems quality requirements for the project. The WAG 6 QAP will be supplemented by subproject QAPs that will identify additional requirements pertaining to each subproject.

  20. Characterization plan for the Oak Ridge National Laboratory Area-Wide Groundwater Program, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1994-08-01

    This characterization plan has been developed as part of the U.S. Department of Energy`s (DOE`s) investigation of the Groundwater Operable Unit (GWOU) at Oak Ridge National Laboratory (ORNL) located near Oak Ridge, Tennessee. The first iteration of the characterization plan is intended to serve as a strategy document to guide subsequent GWOU remedial investigations. The plan provides a rationale and organization for groundwater data acquisition, monitoring, and remedial actions to be performed during implementation of environmental restoration activities associated with the ORNL GWOU. It is important to note that the characterization plan for the ORNL GWOU is not a prototypical work plan. As such, remedial investigations will be conducted using annual work plans to manage the work activities, and task reports will be used to document the results of the investigations. Sampling and analysis results will be compiled and reported annually with a review of data relative to risk (screening level risk assessment review) for groundwater. This characterization plan outlines the overall strategy for the remedial investigations and defines tasks that are to be conducted during the initial phase of investigation. This plan is presented with the understanding that more specific addenda to the plan will follow.

  1. Stress history and geotechnical properties of sediment from the Cape Fear Diapir, Blake Ridge Diapir, and Blake Ridge

    USGS Publications Warehouse

    Winters, W.J.

    2000-01-01

    Geotechnical properties of sediment from Ocean Drilling Program Leg 164 are presented as: (1) normalized shipboard strength ratios from the Cape Fear Diapir, the Blake Ridge Diapir, and the Blake Ridge; and (2) Atterberg limit, vane shear strength, pocket-penetrometer strength, and constant-rate-of-strain consolidation results from Hole 995A, located on the Blake Ridge. This study was conducted to understand the stress history in a region characterized by high sedimentation rates and the presence of gas hydrates. Collectively, the results indicate that sediment from the Blake Ridge exhibits significant underconsolidated behavior, except near the seafloor. At least 10 m of additional overburden was removed by erosion or mass wasting at Hole 993A on the Cape Fear Diapir, compared to nearby sites.

  2. Calculation of Measurement Uncertainty Using Prior Information

    PubMed Central

    Phillips, S. D.; Estler, W. T.; Levenson, M. S.; Eberhardt, K. R.

    1998-01-01

    We describe the use of Bayesian inference to include prior information about the value of the measurand in the calculation of measurement uncertainty. Typical examples show this can, in effect, reduce the expanded uncertainty by up to 85 %. The application of the Bayesian approach to proving workpiece conformance to specification (as given by international standard ISO 14253-1) is presented and a procedure for increasing the conformance zone by modifying the expanded uncertainty guard bands is discussed. PMID:28009370

  3. Transformational Learning through Prior Learning Assessment

    ERIC Educational Resources Information Center

    Stevens, Karen; Gerber, Dan; Hendra, Rick

    2010-01-01

    Upon graduation from University Without Walls (UWW), Robin said, "During first semester you told us that if we allowed it to, this experience [writing a prior learning portfolio] would change us. I was so angry with you for saying that because I liked who I was and didn't want to change. But you were right. And I'm glad." For the past 39…

  4. Cosmic web reconstruction through density ridges: catalogue

    NASA Astrophysics Data System (ADS)

    Chen, Yen-Chi; Ho, Shirley; Brinkmann, Jon; Freeman, Peter E.; Genovese, Christopher R.; Schneider, Donald P.; Wasserman, Larry

    2016-10-01

    We construct a catalogue for filaments using a novel approach called SCMS (subspace constrained mean shift). SCMS is a gradient-based method that detects filaments through density ridges (smooth curves tracing high-density regions). A great advantage of SCMS is its uncertainty measure, which allows an evaluation of the errors for the detected filaments. To detect filaments, we use data from the Sloan Digital Sky Survey, which consist of three galaxy samples: the NYU main galaxy sample (MGS), the LOWZ sample and the CMASS sample. Each of the three data set covers different redshift regions so that the combined sample allows detection of filaments up to z = 0.7. Our filament catalogue consists of a sequence of two-dimensional filament maps at different redshifts that provide several useful statistics on the evolution cosmic web. To construct the maps, we select spectroscopically confirmed galaxies within 0.050 < z < 0.700 and partition them into 130 bins. For each bin, we ignore the redshift, treating the galaxy observations as a 2-D data and detect filaments using SCMS. The filament catalogue consists of 130 individual 2-D filament maps, and each map comprises points on the detected filaments that describe the filamentary structures at a particular redshift. We also apply our filament catalogue to investigate galaxy luminosity and its relation with distance to filament. Using a volume-limited sample, we find strong evidence (6.1σ-12.3σ) that galaxies close to filaments are generally brighter than those at significant distance from filaments.

  5. Oak Ridge National Laboratory Core Competencies

    SciTech Connect

    Roberto, J.B.; Anderson, T.D.; Berven, B.A.; Hildebrand, S.G.; Hartman, F.C.; Honea, R.B.; Jones, J.E. Jr.; Moon, R.M. Jr.; Saltmarsh, M.J.; Shelton, R.B.

    1994-12-01

    A core competency is a distinguishing integration of capabilities which enables an organization to deliver mission results. Core competencies represent the collective learning of an organization and provide the capacity to perform present and future missions. Core competencies are distinguishing characteristics which offer comparative advantage and are difficult to reproduce. They exhibit customer focus, mission relevance, and vertical integration from research through applications. They are demonstrable by metrics such as level of investment, uniqueness of facilities and expertise, and national impact. The Oak Ridge National Laboratory (ORNL) has identified four core competencies which satisfy the above criteria. Each core competency represents an annual investment of at least $100M and is characterized by an integration of Laboratory technical foundations in physical, chemical, and materials sciences; biological, environmental, and social sciences; engineering sciences; and computational sciences and informatics. The ability to integrate broad technical foundations to develop and sustain core competencies in support of national R&D goals is a distinguishing strength of the national laboratories. The ORNL core competencies are: 9 Energy Production and End-Use Technologies o Biological and Environmental Sciences and Technology o Advanced Materials Synthesis, Processing, and Characterization & Neutron-Based Science and Technology. The distinguishing characteristics of each ORNL core competency are described. In addition, written material is provided for two emerging competencies: Manufacturing Technologies and Computational Science and Advanced Computing. Distinguishing institutional competencies in the Development and Operation of National Research Facilities, R&D Integration and Partnerships, Technology Transfer, and Science Education are also described. Finally, financial data for the ORNL core competencies are summarized in the appendices.

  6. Constraints from Seamounts on Pacific Plate or Plume Motion Prior to 80 Ma.

    NASA Astrophysics Data System (ADS)

    Konter, J. G.; Koppers, A. A. P.; Jackson, M. G.; Finlayson, V.; Konrad, K.

    2015-12-01

    The Hawaii-Emperor and Louisville hotspot tracks have long dominated the data set constraining absolute plate motion models. However, prior to ~80 Ma, multiple shorter, discontinuous hotspot trails and oceanic plateaus have been used to constrain absolute plate motion. Based on this earlier work, a clear Hawaii-Emperor style bend seems apparent around 100 Ma in the West Pacific Seamount Province (WPSP). More importantly, the ongoing debate on a plate versus plume motion origin for the Hawaii-Emperor Bend is applicable here, as the ~100 Ma bend may correspond to a global plate reorganization (Matthews et al., EPSL, 2012). Data for a comparison of bends comes from three groups with similar geographic patterns: 1) Mid-Pacific Mountains, Line Islands; 2) Shatsky Rise, Hess Rise, Musician and Wentworth Seamounts; and 3) Wake Seamounts, Marshall Islands, Magellan Seamounts. Both groups 1 and 2 feature a large igneous province (LIP) at their oldest end: Shatsky Rise and the Mid-Pacific Mountains. According to plate reconstructions these LIPs were constructed near all-ridge triple junctions, thus potential plume-ridge interactions need to be clarified before these LIPs can be used to define an absolute mantle reference frame. In contrast, the volcanoes of the third group (Wake, Marshall, Magellan) did erupt truly intra-plate and we therefore argue that this group provides a constraint on plate motion beyond 80 Ma that is independent of plume-ridge interactions. Since the volcanoes in this group are part of the WPSP, which is densely populated with seamounts, a combination of 40Ar/39Ar ages and Sr-Nd-Pb-Hf isotopes is needed to distinguish different hotspot tracks in this region. Backtracking each volcano through its age to its original eruptive location and using compositional color-coding, reveals groupings and patterns that vary by plate motion model, while the temporal patterns of backtracked locations inform us about potential plume motions.

  7. Random template placement and prior information

    NASA Astrophysics Data System (ADS)

    Röver, Christian

    2010-05-01

    In signal detection problems, one is usually faced with the task of searching a parameter space for peaks in the likelihood function which indicate the presence of a signal. Random searches have proven to be very efficient as well as easy to implement, compared e.g. to searches along regular grids in parameter space. Knowledge of the parameterised shape of the signal searched for adds structure to the parameter space, i.e., there are usually regions requiring to be densely searched while in other regions a coarser search is sufficient. On the other hand, prior information identifies the regions in which a search will actually be promising or may likely be in vain. Defining specific figures of merit allows one to combine both template metric and prior distribution and devise optimal sampling schemes over the parameter space. We show an example related to the gravitational wave signal from a binary inspiral event. Here the template metric and prior information are particularly contradictory, since signals from low-mass systems tolerate the least mismatch in parameter space while high-mass systems are far more likely, as they imply a greater signal-to-noise ratio (SNR) and hence are detectable to greater distances. The derived sampling strategy is implemented in a Markov chain Monte Carlo (MCMC) algorithm where it improves convergence.

  8. Prior Knowledge Enhances the Category Dimensionality Effect

    PubMed Central

    Hoffman, Aaron B.; Harris, Harlan D.; Murphy, Gregory L.

    2008-01-01

    A study of the combined influence of prior knowledge and stimulus dimensionality on category learning was conducted. Subjects learned category structures with the same number of necessary dimensions but more or fewer additional redundant dimensions, and with either knowledge-related or knowledge-unrelated features. Minimal-learning models predict that all subjects, regardless of condition, should learn either the same number of dimensions, or else should respond more slowly to each dimension. Despite similar learning rates and response times, subjects learned more features in the high-dimensional than in the low-dimensional condition. Furthermore, prior knowledge interacted with dimensionality, increasing what was learned especially in the high-dimensional case. A second experiment confirmed that the participants did in fact learn more features during the training phase, rather than simply inferring them at test. These effects can be explained by direct associations among features (representing prior knowledge) combined with feedback between features and the category label, as shown by simulations of the knowledge-resonance, or KRES, model of category learning. PMID:18426059

  9. A Nonparametric Prior for Simultaneous Covariance Estimation.

    PubMed

    Gaskins, Jeremy T; Daniels, Michael J

    2013-01-01

    In the modeling of longitudinal data from several groups, appropriate handling of the dependence structure is of central importance. Standard methods include specifying a single covariance matrix for all groups or independently estimating the covariance matrix for each group without regard to the others, but when these model assumptions are incorrect, these techniques can lead to biased mean effects or loss of efficiency, respectively. Thus, it is desirable to develop methods to simultaneously estimate the covariance matrix for each group that will borrow strength across groups in a way that is ultimately informed by the data. In addition, for several groups with covariance matrices of even medium dimension, it is difficult to manually select a single best parametric model among the huge number of possibilities given by incorporating structural zeros and/or commonality of individual parameters across groups. In this paper we develop a family of nonparametric priors using the matrix stick-breaking process of Dunson et al. (2008) that seeks to accomplish this task by parameterizing the covariance matrices in terms of the parameters of their modified Cholesky decomposition (Pourahmadi, 1999). We establish some theoretic properties of these priors, examine their effectiveness via a simulation study, and illustrate the priors using data from a longitudinal clinical trial.

  10. Diversity priors for learning early visual features

    PubMed Central

    Xiong, Hanchen; Rodríguez-Sánchez, Antonio J.; Szedmak, Sandor; Piater, Justus

    2015-01-01

    This paper investigates how utilizing diversity priors can discover early visual features that resemble their biological counterparts. The study is mainly motivated by the sparsity and selectivity of activations of visual neurons in area V1. Most previous work on computational modeling emphasizes selectivity or sparsity independently. However, we argue that selectivity and sparsity are just two epiphenomena of the diversity of receptive fields, which has been rarely exploited in learning. In this paper, to verify our hypothesis, restricted Boltzmann machines (RBMs) are employed to learn early visual features by modeling the statistics of natural images. Considering RBMs as neural networks, the receptive fields of neurons are formed by the inter-weights between hidden and visible nodes. Due to the conditional independence in RBMs, there is no mechanism to coordinate the activations of individual neurons or the whole population. A diversity prior is introduced in this paper for training RBMs. We find that the diversity prior indeed can assure simultaneously sparsity and selectivity of neuron activations. The learned receptive fields yield a high degree of biological similarity in comparison to physiological data. Also, corresponding visual features display a good generative capability in image reconstruction. PMID:26321941

  11. Diversity priors for learning early visual features.

    PubMed

    Xiong, Hanchen; Rodríguez-Sánchez, Antonio J; Szedmak, Sandor; Piater, Justus

    2015-01-01

    This paper investigates how utilizing diversity priors can discover early visual features that resemble their biological counterparts. The study is mainly motivated by the sparsity and selectivity of activations of visual neurons in area V1. Most previous work on computational modeling emphasizes selectivity or sparsity independently. However, we argue that selectivity and sparsity are just two epiphenomena of the diversity of receptive fields, which has been rarely exploited in learning. In this paper, to verify our hypothesis, restricted Boltzmann machines (RBMs) are employed to learn early visual features by modeling the statistics of natural images. Considering RBMs as neural networks, the receptive fields of neurons are formed by the inter-weights between hidden and visible nodes. Due to the conditional independence in RBMs, there is no mechanism to coordinate the activations of individual neurons or the whole population. A diversity prior is introduced in this paper for training RBMs. We find that the diversity prior indeed can assure simultaneously sparsity and selectivity of neuron activations. The learned receptive fields yield a high degree of biological similarity in comparison to physiological data. Also, corresponding visual features display a good generative capability in image reconstruction.

  12. INDEPENDENT VERIFICATION OF THE CENTRAL CAMPUS AND SOUTHEAST LABORATORY COMPLEX BUILDING SLABS AT OAK RIDGE NATIONAL LABORATORY, OAK RIDGE, TENNESSEE

    SciTech Connect

    Weaver, Phyllis C.

    2012-07-24

    Oak Ridge Associated Universities/Oak Ridge Institute for Science and Education (ORAU/ORISE) has completed the independent verification survey of the Central Campus and Southeast Lab Complex Building Slabs. The results of this effort are provided. The objective of this verification survey was to provide independent review and field assessment of remediation actions conducted by SEC, and to independently assess whether the final radiological condition of the slabs met the release guidelines.

  13. Morphodynamics and slope stability at Mergui Ridge, off western Thailand

    NASA Astrophysics Data System (ADS)

    Schwab, J.; Gross, F.; Krastel, S.; Jintasaeranee, P.; Bunsomboonsakul, S.; Winkelmann, D.; Weinrebe, W.

    2012-04-01

    2D seismic data from the top and the western slope of the Mergui Ridge (200 km off the Thai west coast) have been acquired during MASS cruise III in January 2011 in water depths between 300 and 2200 m. The Mergui Ridge is a part of the outer shelf slope off the Thai-Malay Peninsula and forms the eastern boundary of the East Andaman Basin. Structural features in the working area include faulted older slope sediments at the transition from Mergui Ridge to East Andaman Basin that are onlapping on the (acoustic) basement of Mergui Ridge. At their top these sediments are bordered by a pronounced erosive unconformity. Younger sedimentary units on top include three E-W elongated carbonate platforms. Moreover, drift sediments are deposited on top of the ridge, comprising features such as large scale sediment waves and moats around the platforms indicating transport and reworking of the sediments. These sediments are thinning towards the edge of the ridge where a zone of non-sedimentation prevails. In the East Andaman Basin younger sediments comprise disturbed and partially faulted units that are overlain by plastered drifts with increasing thickness towards south, where pronounced sediment waves within the drifts may indicate slope normal sediment transport by bottom currents. At the basin ridge transition, within the drift sediments on top of Mergui Ridge, and at the edge of the ridge several smaller scale mass transport deposits were identified. These MTDs indicate a general instability of the slope. Instability and general morphology of the slope may result from long-term tectonic processes such as extension due to backarc basin formation in the Andaman Sea basin. Moreover, phases of uplift, erosion and subsidence may have contributed to faulting and deformation of older units in our working area. Ongoing tectonics might still cause deformation and instability. In addition, bottom currents may presently play an important role concerning morphodynamic development by

  14. The Global Distribution of Wrinkle Ridges on Venus

    NASA Astrophysics Data System (ADS)

    Bilotti, Frank; Suppe, John

    1999-05-01

    New digital mapping of over 65,000 wrinkle ridges of the plains of Venus shows a strong correlation between the location and orientation of these long, low-amplitude compressive anticlines and major features of the geoid and long-wavelength topography. Regions with wrinkle ridges occupy 43% of the plains and are strongly skewed toward low elevations and negative geoid anomalies. About 93% of the wrinkle ridge plains lie below mean planetary radius and 72% have negative geoid anomalies. In contrast, the extensional rift zones of Venus are strongly skewed toward high elevations and positive geoid anomalies. Thus compressive deformation dominates the topographic and geoid lows, whereas extensional rifting is generally restricted to the highs. These observations are consistent with geoid-based stress models that predict compression in geoid lows and extension in geoid highs. The orientations of wrinkle ridges are generally consistent over regions extending for 1000-10,000 km. Many regions have multiple sets of wrinkle ridges of different orientations reflecting multiple episodes and directions of compression; however, about 80% of the regions display a single dominant wrinkle ridge orientation, with secondary orientations subordinate. The dominant wrinkle ridge orientations in many regions follow the contours of long-wavelength topography and geoid or lie along the axes of troughs in the geoid. Thus the maximum horizontal compression recorded by the folds is commonly parallel to the present-day gradient in geoid and topography, although some regions are strong exceptions, perhaps reflecting changes in topography and geoid with time. The dominant wrinkle ridge trends ring several major geoid and topographic swells, especially Western Aphrodite Terra and Lada Terra, with ring diameters of 75-120° (8000-13,000 km). In addition there are smaller rings of wrinkle ridges around the swells in Themis, Eistla, and Bell regiones, especially Gula Mons, with ring diameters of 25

  15. Oak Ridge Reservation Annual Site Environmental Report for 2010

    SciTech Connect

    Thompson, Sharon D

    2011-10-01

    The Oak Ridge Reservation Annual Site Environmental Report is prepared annually and presents summary environmental data to (1) characterize environmental performance, (2) summarize environmental occurrences reported during the year, (3) confirm compliance with environmental standards and requirements, and (4) highlight significant program activities. The report fulfills the requirement contained in DOE Order 231.1A, Environment, Safety and Health Reporting (DOE 2004) that an integrated annual site environmental report be prepared. The results summarized in this report are based on data collected prior to and through 2010. This report is not intended to nor does it present the results of all environmental monitoring associated with the ORR. Data collected for other site and regulatory purposes, such as environmental restoration/remedial investigation reports, waste management characterization sampling data, and environmental permit compliance data, are presented in other documents that have been prepared in accordance with applicable DOE guidance and/or laws and are referenced herein as appropriate. Appendix A to this report identifies corrections to the 2009 report. Appendix B contains a glossary of technical terms that may be useful for understanding the terminology used in this document. Environmental monitoring on the ORR consists primarily of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring involves the collection and analysis of samples or measurements of liquid and gaseous effluents at the points of release to the environment; these measurements allow the quantification and official reporting of contaminant levels, assessment of radiation and chemical exposures to the public, and demonstration of compliance with applicable standards and permit requirements. Environmental surveillance consists of direct measurements and collection and analysis of samples taken from the site and its environs exclusive of effluents

  16. Oak Ridge Reservation Annual Site Environmental Report for 2009

    SciTech Connect

    Bechtel Jacobs

    2010-09-01

    The Oak Ridge Reservation Annual Site Environmental Report is prepared animally and presents summary environmental data to (1) characterize environmental performance, (2) summarize environmental occurrences reported during the year, (3) confirm compliance with environmental standards and requirements, and (4) highlight significant program activities. The report fulfills the requirement contained in DOE Order 231.1 A, Environment, Safety and Health Reporting (DOE 2004) that an integrated annual site environmental report be prepared. The results summarized in this report are based on data collected prior to and through 2009. This report is not intended to nor does it present the results of all environmental monitoring associated with the ORR. Data collected for other site and regulatory purposes, such as environmental restoration/remedial investigation reports, waste management characterization sampling data, and environmental permit compliance data, are presented in other documents that have been prepared in accordance with applicable DOE guidance and/or laws and are referenced herein as appropriate. Appendix A to this report identifies corrections to the 2008 report. Appendix B contains a glossary of technical terms that may be useful for understanding the terminology used in this document. Environmental monitoring on the ORR consists primarily of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring involves the collection and analysis of samples or measurements of liquid and gaseous effluents at the points of release to the environment; these measurements allow the quantification and official reporting of contaminant levels, assessment of radiation and chemical exposures to the public, and demonstration of compliance with applicable standards and permit requirements. Environmental surveillance consists of direct measurements and collection and analysis of samples taken from the site and its environs exclusive of effluents

  17. Oak Ridge Reservation Annual Site Environmental Report for 2009

    SciTech Connect

    Thompson, Sharon D; Loffman, Regis S

    2010-10-01

    The Oak Ridge Reservation Annual Site Environmental Report is prepared annually and presents summary environmental data to (1) characterize environmental performance, (2) summarize environmental occurrences reported during the year, (3) confirm compliance with environmental standards and requirements, and (4) highlight significant program activities. The report fulfills the requirement contained in DOE Order 231.1A, Environment, Safety and Health Reporting (DOE 2004) that an integrated annual site environmental report be prepared. The results summarized in this report are based on data collected prior to and through 2009. This report is not intended to nor does it present the results of all environmental monitoring associated with the ORR. Data collected for other site and regulatory purposes, such as environmental restoration/remedial investigation reports, waste management characterization sampling data, and environmental permit compliance data, are presented in other documents that have been prepared in accordance with applicable DOE guidance and/or laws and are referenced herein as appropriate. Appendix A to this report identifies corrections for the 2008 report. Appendix B contains a glossary of technical terms that may be useful for understanding the terminology used in this document. Environmental monitoring on the ORR consists primarily of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring involves the collection and analysis of samples or measurements of liquid and gaseous effluents at the points of release to the environment; these measurements allow the quantification and official reporting of contaminant levels, assessment of radiation and chemical exposures to the public, and demonstration of compliance with applicable standards and permit requirements. Environmental surveillance consists of direct measurements and collection and analysis of samples taken from the site and its environs exclusive of effluents

  18. Ultraslow Ridges through Binoculars: Teleseismic Earthquake Characteristics Illuminate Accretion Processes

    NASA Astrophysics Data System (ADS)

    Schlindwein, V.; Laederach, C.; Korger, E.

    2011-12-01

    Ultraslow spreading ridges with full spreading rates < 20 mm/y constitute the largest portion of the global mid-ocean ridge system, yet 85% of these ridges are still unexplored. Understanding the structure and dynamics of crustal production and the associated hydrothermal systems including their biota has become a major challenge of modern mid-ocean ridge research. The complex interplay between tectonic, magmatic and hydrothermal processes that governs lithospheric accretion at ultraslow-spreading ridges is so poorly investigated because their main representatives, the Arctic ridge system and the Southwest Indian Ridge (SWIR), are situated in remote areas with difficult working conditions. While local seismicity studies with ocean bottom seismometers on slow and fast spreading ridges have greatly contributed to our understanding of active accretion processes, comparable studies are lacking for ultraslow spreading ridges forcing to fall back on studies of larger earthquakes recorded on land. Using teleseismic data from the Bulletin of the International Seismological Centre between the years 1976 and 2010, we performed a systematic analysis of the ridge related seismicity (M > 4) of the ultraslow spreading Arctic ridge system and the SWIR. These ridges were divided in 11 sections of uniform seismological, topographic and geological characteristics, totalling a length of 7200 km with the rift axis defined as a multisegment line along the topographic low of the rift valley. Only events within 30 km of the rift axis were included in our study. We found that magmatic and amagmatic accretion sections cannot be distinguished neither by event rate, moment release rate, maximum earthquake magnitude, nor by the b-value. Yet using single link cluster analysis for identification of swarms of 8 or more earthquakes, small clusters of 2-7 earthquakes and single events, we found that sections with amagmatic accretion lack swarms and show consistently a high percentage of single

  19. PriorsEditor: a tool for the creation and use of positional priors in motif discovery

    PubMed Central

    Klepper, Kjetil; Drabløs, Finn

    2010-01-01

    Summary: Computational methods designed to discover transcription factor binding sites in DNA sequences often have a tendency to make a lot of false predictions. One way to improve accuracy in motif discovery is to rely on positional priors to focus the search to parts of a sequence that are considered more likely to contain functional binding sites. We present here a program called PriorsEditor that can be used to create such positional priors tracks based on a combination of several features, including phylogenetic conservation, nucleosome occupancy, histone modifications, physical properties of the DNA helix and many more. Availability: PriorsEditor is available as a web start application and downloadable archive from http://tare.medisin.ntnu.no/priorseditor (requires Java 1.6). The web site also provides tutorials, screenshots and example protocol scripts. Contact: kjetil.klepper@ntnu.no PMID:20628076

  20. Evidence for chemically heterogeneous Arctic mantle beneath the Gakkel Ridge

    NASA Astrophysics Data System (ADS)

    D'Errico, Megan E.; Warren, Jessica M.; Godard, Marguerite

    2016-02-01

    Ultraslow spreading at mid-ocean ridges limits melting due to on-axis conductive cooling, leading to the prediction that peridotites from these ridges are relatively fertile. To test this, we examined abyssal peridotites from the Gakkel Ridge, the slowest spreading ridge in the global ocean ridge system. Major and trace element concentrations in pyroxene and olivine minerals are reported for 14 dredged abyssal peridotite samples from the Sparsely Magmatic (SMZ) and Eastern Volcanic (EVZ) Zones. We observe large compositional variations among peridotites from the same dredge and among dredges in close proximity to each other. Modeling of lherzolite trace element compositions indicates varying degrees of non-modal fractional mantle melting, whereas most harzburgite samples require open-system melting involving interaction with a percolating melt. All peridotite chemistry suggests significant melting that would generate a thick crust, which is inconsistent with geophysical observations at Gakkel Ridge. The refractory harzburgites and thin overlying oceanic crust are best explained by low present-day melting of a previously melted heterogeneous mantle. Observed peridotite compositional variations and evidence for melt infiltration demonstrates that fertile mantle components are present and co-existing with infertile mantle components. Melt generated in the Gakkel mantle becomes trapped on short length-scales, which produces selective enrichments in very incompatible rare earth elements. Melt migration and extraction may be significantly controlled by the thick lithosphere induced by cooling at such slow spreading rates. We propose the heterogeneous mantle that exists beneath Gakkel Ridge is the consequence of ancient melting, combined with subsequent melt percolation and entrapment. Initial modes of depleted mantle composition from Hellebrand et al. (2002b). Melt compositions are from Brunelli et al. (2014) in

  1. Pesticide Leaching from Agricultural Fields with Ridges and Furrows.

    PubMed

    Leistra, Minze; Boesten, Jos J T I

    2010-11-01

    In the evaluation of the risk of pesticide leaching to groundwater, the soil surface is usually assumed to be level, although important crops like potato are grown on ridges. A fraction of the water from rainfall and sprinkler irrigation may flow along the soil surface from the ridges to the furrows, thus bringing about an extra load of water and pesticide on the furrow soil. A survey of the literature reveals that surface-runoff from ridges to furrows is a well-known phenomenon but that hardly any data are available on the quantities of water and pesticide involved. On the basis of a field experiment with additional sprinkler irrigation, computer simulations were carried out with the Pesticide Emission Assessment at Regional and Local scales model for separate ridge and furrow systems in a humic sandy potato field. Breakthrough curves of bromide ion (as a tracer for water flow) and carbofuran (as example pesticide) were calculated for 1-m depth in the field. Bromide ion leached comparatively fast from the furrow system, while leaching from the ridge system was slower showing a maximum concentration of about half of that for the furrow system. Carbofuran breakthrough from the furrow system began about a month after application and increased steadily to substantial concentrations. Because the transport time of carbofuran in the ridge soil was much longer, no breakthrough occurred in the growing season. The maximum concentration of carbofuran leaching from the ridge-furrow field was computed to be a factor of six times as high as that computed for the corresponding level field. The study shows that the risk of leaching of pesticides via the furrow soil can be substantially higher than that via the corresponding level field soil.

  2. Tectonic control on deltaic cyclicity in the Ridge Basin, California

    SciTech Connect

    Ehman, K.D.; Sullivan, M.D.; May, S.R. )

    1994-04-01

    Upper Miocene sedimentary rocks of the Ridge basin provide an opportunity to evaluate the relationship between tectonics, subsidence history, and basin fill in an extensional strike-slip setting. Cyclicity of strata within the Ridge basin, which is expressed by the progradational members of the Ridge Route Formation and retrogradation within the Violin Breccia, records sedimentological response to basin margin faulting and variations in accomodation. This cyclicity is best developed within the members of the Peace Valley Formation where thick shaly lacustrine packages are punctuated by progradational sandy fluvial-deltaic units of the Ridge Route Formation. A geohistory curve constructed for the lower portion of the Ridge Basin Group based on magnetostratigraphic age control shows high rates of accomodation with dramatic changes in the interval subsidence rate. There is a significant correlation between increases in subsidence rate and the deposition of thick lacustrine shales in the basin axis and coeval progradation of the Violin Breccia along the western margin of the basin. The Violin Breccia strata were deposited contemporaneously with movement along the San Gabriel fault, and during periods of increased faulting, it prograded into the basin in response to higher sedimentation rates associated with erosion of the uplifted footwall (high relief margin). Progradational intervals of the Violin Breccia, which correspond to the highest rates of subsidence within the basin, are out of phase with the progradation of the sand-prone members of the Ridge Route Formation being derived from the east (low relief margin) during periods of lower subsidence rate. Decreases of subsidence rate generally correspond to periods of progradation of the sandstone members of the Ridge Route Formation and retrogradation of the Violin Breccia until the next period of tectonic subsidence which starts the cycle over again.

  3. Quality assurance project plan for the Chestnut Ridge Fly Ash Pond Stabilization Project at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1996-07-01

    The Chestnut Ridge Fly Ash Pond Stabilization (CRFAPS) Project will stabilize a 19-m-high (62-ft-high) earthen embankment across Upper McCoy Branch situated along the southern slope of Chestnut Ridge. This task will be accomplished by raising the crest of the embankment, reinforcing the face of the embankment, removing trees from the face and top of the embankment, and repairing the emergency spillway. The primary responsibilities of the team members are: Lockheed Martin Energy Systems, Inc., (Energy Systems) will be responsible for project integration, technical support, Title 3 field support, environmental oversight, and quality assurance (QA) oversight of the project; Foster Wheeler Environmental Corporation (FWENC) will be responsible for design and home office Title 3 support; MK-Ferguson of Oak Ridge Company (MK-F) will be responsible for health and safety, construction, and procurement of construction materials. Each of the team members has a QA program approved by the US Department of Energy (DOE) Oak Ridge Operations. This project-specific QA project plan (QAPP), which is applicable to all project activities, identifies and integrates the specific QA requirements from the participant`s QA programs that are necessary for this project.

  4. Best management practices plan for the Chestnut Ridge-Filled Coal Ash Pond at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1996-05-01

    The Chestnut Ridge Filled Coal Ash Pond (FCAP) Project has been established to satisfy Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) requirements for the Chestnut Ridge Operable Unit 2. FCAP is on Chestnut Ridge, approximately 0.5 miles south of the Y-12 Plant. A 62-foot high earthen dam across Upper McCoy Branch was constructed in 1955 to create a pond to serve as a settling basin for fly and bottom ashes generated by burning coal at the Y-12 Steam Plant. Ash from the steam was mixed with water to form a slurry and then pumped to the crest of Chestnut Ridge and released through a large pipe to flow across the Sluice Channel area and into the pond. The ash slurry eventually overtopped the dam and flowed along Upper McCoy Branch to Rogers Quarry. The purpose of this document is to provide a site-specific Best Management Practices (BMP) Plan for construction associated with environmental restoration activities at the FCAP Site.

  5. Californium Electrodepositions at Oak Ridge National Laboratory

    SciTech Connect

    Boll, Rose Ann

    2015-01-01

    Electrodepositions of californium isotopes were successfully performed at Oak Ridge National Laboratory (ORNL) during the past year involving two different types of deposition solutions, ammonium acetate (NH4C2H3O2) and isobutanol ((CH3)2CHCH2OH). A californium product that was decay enriched in 251Cf was recovered for use in super-heavy element (SHE) research. This neutron-rich isotope, 251Cf, provides target material for SHE research for the potential discovery of heavier isotopes of Z=118. The californium material was recovered from aged 252Cf neutron sources in storage at ORNL. These sources have decayed for over 30 years, thus providing material with a very high 251Cf-to-252Cf ratio. After the source capsules were opened, the californium was purified and then electrodeposited using the isobutanol method onto thin titanium foils for use in an accelerator at the Joint Institute for Nuclear Research in Dubna, Russia. Another deposition method, ammonium acetate, was used to produce a deposition containing 1.7 0.1 Ci of 252Cf onto a stainless steel substrate. This was the largest single electrodeposition of 252Cf ever prepared. The 252Cf material was initially purified using traditional ion exchange media, such as AG50-AHIB and AG50-HCl, and further purified using a TEVA-NH4SCN system to remove any lanthanides, resulting in the recovery of 3.6 0.1 mg of purified 252Cf. The ammonium acetate deposition was run with a current of 1.0 amp, resulting in a 91.5% deposition yield. Purification and handling of the highly radioactive californium material created additional challenges in the production of these sources.

  6. Aging Cognition Unconfounded by Prior Test Experience

    PubMed Central

    2016-01-01

    Objective. Investigate time-related age differences in cognitive functioning without influences of prior test experience. Methods. Cognitive scores were compared in different individuals from the same birth years who were tested in different years, when they were at different ages. These types of quasi-longitudinal comparisons were carried out on data from three large projects: the Seattle Longitudinal Study [Schaie, K. W. (2013). Developmental influences on adult intelligence: The Seattle Longitudinal Study (2nd ed.). New York, NY: Oxford University Press], the Betula Project [Ronnlund, M., & Nilsson, L-G. (2008). The magnitude, generality, and determinants of Flynn effects on forms of declarative memory and visuospatial ability: Time-sequential analyses of data from a Swedish cohort study. Intelligence, 36, 192–209], and the Virginia Cognitive Aging Project (this study). Results. In each data set, the results revealed that the estimates of cognitive change with no prior test experience closely resembled the estimates of age relations based on cross-sectional comparisons. Furthermore, longitudinal comparisons revealed positive changes at young ages that gradually became more negative with increased age, whereas all of the estimates of change without prior test experience were negative except those for measures of vocabulary. Discussion. The current results suggest that retest effects can distort the mean age trends in longitudinal comparisons that are not adjusted for experience. Furthermore, the findings can be considered robust because the patterns were similar across three data sets involving different samples of participants and cognitive tests, and across different methods of controlling experience effects in the new data set. PMID:25182845

  7. Glomangiosarcoma Arising from a Prior Biopsy Site

    PubMed Central

    Maselli, Amy M.; Jambhekar, Amani V.

    2017-01-01

    Summary: Glomangiosarcoma represents a rare malignant variant of the benign glomus tumor that typically presents as a tender, slowly growing nodule with a predilection for the lower extremities. Unlike their benign counterparts, glomangiosarcomas may display aggressive characteristics such as large size, local invasion, and a tendency to recur after excision. Although wide local excision remains the treatment of choice, rare cases of systemic metastasis have been previously reported. We present a case of glomangiosarcoma arising at a prior biopsy site after excision of an unknown soft tissue lesion. PMID:28203514

  8. The ridges of Europa: Extensions of adjacent topography onto their flanks

    NASA Astrophysics Data System (ADS)

    Greenberg, Richard; Sak, Peter B.

    2014-03-01

    The surface of Europa displays numerous generations of intersecting arrays of linear ridges. At some locations along these ridges, older ridges on adjacent terrain appear to extend up the flank of a more recent ridge. It has thus been suggested that the ridges may have formed by upturning of that adjacent terrain. However, the newer ridges generally appear to be material deposited over the older terrain. Here we consider how the morphology of the overprinted topography may have been inherited by the more recent ridges. An analogous process occurs along some sediment-starved convergent plate boundaries on Earth, where the poorly consolidated material of a frontal prism of an overriding plate is pushed over preexisting ridges and seamounts on the downgoing plate. The overriding plate inherits the morphology of the downgoing plate even though the actual extension of that topography has been underthrust and buried. A well-studied example lies offshore of Costa Rica where the Caribbean plate overrides the Cocos plate. Experiments show other mechanisms as well: mass-wasting down a flank can result in extensions of adjacent ridges thanks to the geometry imposed by a constant angle of repose; in addition, more pronounced extensions of the older ridges result if the new ridge grows as it is bulldozed from behind (i.e., from the central groove of a double ridge on Europa). The shapes of the ridge extensions are distinctly different in these two cases. If tidal pumping extrudes material to the surface at the center of a double ridge, it might drive the latter mechanism. The ridge extensions observed on the flanks of more recent ridges may provide a crucial diagnostic of dominant ridge-building mechanisms when and if additional images are obtained at high resolution from future exploration. In additional to their morphology, the distribution of ridge extensions at only isolated locales may also provide constraints on ridge formation processes and their diversity.

  9. Design demonstrations for category B tank systems at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1994-11-01

    This document presents design demonstrations conducted of liquid low-level waste (LLLW) storage tank systems located at the Oak Ridge National Laboratory (ORNL). Demonstration of the design of these tank systems has been stipulated by the Federal Facility Agreement (FFA) between the US Environmental Protection Agency (EPA)-Region IV; the Tennessee Department of Environment and Conservation (TDEC); and the DOE. The FFA establishes four categories of tanks. These are: Category A -- New or replacement tank systems with secondary containment; Category B -- Existing tank systems with secondary containment; Category C -- Existing tank systems without secondary containment; Category D -- Existing tank systems without secondary containment that are removed from service. This document provides a design demonstration of the secondary containment and ancillary equipment of 11 tank systems listed in the FFA as Category B. The design demonstration for each tank is presented.

  10. Resource Management plan for the Oak Ridge Reservation. Volume 28, Wetlands on the Oak Ridge Reservation

    SciTech Connect

    Cunningham, M.; Pounds, Larry

    1991-12-01

    A survey of wetlands on the Oak Ridge Reservation (ORR) was conducted in 1990. Wetlands occurring on ORR were identified using National Wetlands Inventory (NWI) maps and field surveys. More than 120 sites were visited and 90 wetlands were identified. Wetland types on ORR included emergent communities in shallow embayments on reservoirs, emergent and aquatic communities in ponds, forested wetland on low ground along major creeks, and wet meadows and marshes associated with streams and seeps. Vascular plant species occurring on sites visited were inventoried, and 57 species were added to the checklist of vascular plants on ORR. Three species listed as rare in Tennessee were discovered on ORR during the wetlands survey. The survey provided an intensive ground truth of the wetlands identified by NWI and offered an indication of wetlands that the NWI remote sensing techniques did not detect.

  11. Management of spent nuclear fuel on the Oak Ridge Reservation, Oak Ridge, Tennessee: Environmental assessment

    SciTech Connect

    1996-02-01

    On June 1, 1995, DOE issued a Record of Decision [60 Federal Register 28680] for the Department-wide management of spent nuclear fuel (SNF); regionalized storage of SNF by fuel type was selected as the preferred alternative. The proposed action evaluated in this environmental assessment is the management of SNF on the Oak Ridge Reservation (ORR) to implement this preferred alternative of regional storage. SNF would be retrieved from storage, transferred to a hot cell if segregation by fuel type and/or repackaging is required, loaded into casks, and shipped to off-site storage. The proposed action would also include construction and operation of a dry cask SNF storage facility on ORR, in case of inadequate SNF storage. Action is needed to enable DOE to continue operation of the High Flux Isotope Reactor, which generates SNF. This report addresses environmental impacts.

  12. Level 3 Baseline Risk Assessment for Building 3515 at Oak Ridge National Lab., Oak Ridge, TN

    SciTech Connect

    Wollert, D.A.; Cretella, F.M.; Golden, K.M.

    1995-08-01

    The baseline risk assessment for the Fission Product Pilot Plant (Building 3515) at the Oak Ridge National laboratory (ORNL) provides the Decontamination and Decommissioning (D&D) Program at ORNL and Building 3515 project managers with information concerning the results of the Level 3 baseline risk assessment performed for this building. The document was prepared under Work Breakdown Structure 1.4.12.6.2.01 (Activity Data Sheet 3701, Facilities D&D) and includes information on the potential long-term impacts to human health and the environment if no action is taken to remediate Building 3515. Information provided in this document forms the basis for the development of remedial alternatives and the no-action risk portion of the Engineering Evaluation/Cost Analysis report.

  13. Remedial investigation work plan for Chestnut Ridge Operable Unit 4 (Rogers Quarry/Lower McCoy Branch) at the Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1993-09-01

    The Oak Ridge Y-12 Plant includes - 800 acres near the northeast comer of the reservation and adjacent to the city of Oak Ridge (Fig. 1-1). The plant is a manufacturing and developmental engineering facility that produced components for various nuclear weapons systems and provides engineering support to other Energy Systems facilities. More than 200 contaminated sites have been identified at the Y-12 Plant that resulted from past waste management practices. Many of the sites have operable units (OUs) based on priority and on investigative and remediation requirements. This Remedial Investigation RI work plan specifically addresses Chestnut Ridge OU 4. Chestnut Ridge OU 4 consists of Rogers Quarry and Lower McCoy Branch (MCB). Rogers Quarry, which is also known as Old Rogers Quarry or Bethel Valley Quarry was used for quarrying from the late 1940s or early 1950s until about 1960. Since that time, the quarry has been used for disposal of coal ash and materials from Y-12 production operations, including classified materials. Disposal of coal ash ended in July 1993. An RI is being conducted at this site in response to CERCLA regulations. The overall objectives of the RI are to collect data necessary to evaluate the nature and extent of contaminants of concern, support an Ecological Risk Assessment and a Human Health Risk Assessment, support the evaluation of remedial alternatives, and ultimately develop a Record of Decision for the site. The purpose of this work plan is to outline RI activities necessary to define the nature and extent of suspected contaminants at Chestnut Ridge OU 4. Potential migration pathways also will be investigated. Data collected during the RI will be used to evaluate the risk posed to human health and the environment by OU 4.

  14. Lomonosov Ridge as a Natural Component of Continental Margin

    NASA Astrophysics Data System (ADS)

    Poselov, V.; Kaminsky, V. D.; Butsenko, V. V.; Grikurov, G. E.

    2010-12-01

    In geodynamic context, Lomonosov Ridge is interpreted as a rifted passive margin framing the Eurasian oceanic basin. At the same time its near-Siberian segment is intimately associated with the Russian Arctic shelf, as evidenced by morphological data and the results of “Trans-Arctic 1992” and “Arctic-2007” geotransect studies. Coring and ACEX data demonstrated the presence in the uppermost geological section of the ridge of Late Cretaceous through Cenozoic sediments and Jurassic-Cretaceous sedimentary rocks; the latter may belong to deeper levels of sedimentary cover, or may represent the Mesozoic folded basement. Coarse bottom debris contains also the fragments of Riphean-Paleozoic rocks probably derived from the local bedrock source. Structure of sedimentary cover is imaged by continuous seismic observations from the shelf of East Siberian Sea along the length of Lomonosov Ridge to 85 N. In the upper part of the section there are two sedimentary sequences separated by a regional unconformity; their seismic velocities are 2.4-3.1 km/s in the upper sequence and 3.4-4.0 km/s in the lower one, and the total thickness reaches ~ 8 km in the deepest part of New Siberian Basin. Both these sequences and the unconformity are traced from Lomonosov Ridge into Amundsen Basin on seismic reflection sections obtained by drifting ice stations North Pole 2479 and 2480. The low-velocity sediments are underlain by a metasedimetary sequence with velocities decreasing from 4.7-4.9 km/s on the shelf to 4.4-4.9 km/s beneath continental slope and 4.2-4.8 km/s on Lomonosov Ridge. The thickness of metasedimentary sequence is about 7 km on the shelf, up to 3.5 km under continental slope, and strongly variable (1-5 km) on Lomonosov Ridge. The upper layer of consolidated crust is 8-9 km thick on the shelf with velocities 6.1-6.2 km/s; on Lomonosov Ridge both its thickness and velocities increase to 10 km and 6.0-6.4 km/s, respectively. In the lower crust the velocities do not exceed 6

  15. Ultra-slow-spreading - A New Class of Ocean Ridge

    NASA Astrophysics Data System (ADS)

    Dick, H. J.; Lin, J.; Michael, P. J.; Schouten, H.; Snow, J. E.

    2002-12-01

    Surveys of the the SW Indian and Gakkel Ridges show that ultra-slow spreading ridges are as different from slow spreading ridges as fast spreading ridges are from slow ? perhaps more so. At an effective spreading rate for mantle upwelling <~12 mm/yr (the full rate spreading component measured orthogonal to the ridge trend) there are dramatic changes. Magmatism becomes discontinuous, with mantle peridotite emplaced directly to the sea floor over large regions. Local magmatic centers are either ephemeral point source or occur at long-lived cross-axis volcanic highs. The latter are principally localized at bends in the ridge trend or at ridge transform intersections. Mantle peridotites emplaced to the sea floor range from harzburgite to lherzolite, despite low levels of melt production, suggesting that much of this variability predates the ridge melting event. While high-pressure vein assemblages are not present, evidence for late stage low-pressure melt impregnation is common, suggesting that the peridotites underwent partial fusion. This likely eliminated pre-existing vein assemblages. Ridge basalts differ from those at faster spreading ridges as they are generally enriched - possible evidence of a pre-existing vein assemblage. In magmatically active areas, rift axes are sub-orthogonal to the spreading direction with high-angle normal faults dominating the formation of axial and rift valley relief. In the absence of active magmatism, rift valley walls are more subdued, and follow the ridge trend. The walls of amagmatic spreading segments are often lower than those at magmatic segments and are either highly irregular or dominated by low-angle normal faults. The latter dip ~14°-18° and slope down from the crest of the rift valley wall to the floor of the axial trough on essentially a single fault surface. Despite this an orthogonal fabric defined by 50 to 200-m high-angle normal fault scarps, reflecting brittle plate extension, is ubiquitous. This is most easily

  16. Enabling Integration and Synthesis through the Ridge 2000 Data Portal

    NASA Astrophysics Data System (ADS)

    Ryan, W. B.; Ferrini, V.; Carbotte, S. M.; O'Hara, S.; Arko, R. A.; Bonczkowski, J.; Chan, S.

    2009-12-01

    Achieving an integrated, holistic understanding of global mid-ocean ridge (MOR) processes through the Ridge 2000 Program relies heavily on the sharing of data across disciplinary boundaries. Although most Ridge 2000 research has been focused on three Integrated Study Sites (ISSs), data from throughout the global mid-ocean ridge (MOR) system will also be important in the integration and synthesis phase of the program. The Ridge 2000 Data Portal (www.marine-geo.org/portals/ridge2000) is a resource established to facilitate the sharing, discovery, and integration of Ridge 2000-relevant data by providing data documentation and access. The Data Portal includes an inventory of field programs and activities, raw and derived data files, and access to publications and remote data sets in specialized data systems (e.g. PetDB, www.petdb.org; GenBank, www.ncbi.nlm.nih.gov; NGDC, www.ngdc.noaa.gov). Access to the R2K database is provided through several pathways, including a web-based search interface (www.marine-geo.org/tools/search) that now includes basic and advanced search functionality. New versions of our data exploration and visualization tool GeoMapApp (www.geomapapp.org) includes a newly designed menu system with cascading and tear-off menus, a new Layer Manager that lists selected layers and enables re-ordering and rendering with variable transparency, a Go To option that allows direct zooming to areas of interest, and an Add Image Overlay option for importing georeferenced images. New data sets are continually added to both GeoMapApp and Virtual Ocean (www.virtualocean.org), a 3D virtual globe with GeoMapApp functionality. Several Ridge 2000 data sets are also bundled for viewing in Google Earth (www.marine-geo.org/tools/kmls.php). This poster will highlight new functionality and data sets relevant to Ridge 2000 Integration and Synthesis, and will provide comparisons of several data sets that exist for each ISS.

  17. The timescales of magma evolution at mid-ocean ridges

    NASA Astrophysics Data System (ADS)

    Brandl, Philipp A.; Regelous, Marcel; Beier, Christoph; O'Neill, Hugh St. C.; Nebel, Oliver; Haase, Karsten M.

    2016-01-01

    Oceanic crust is continuously created at mid-ocean ridges by decompression melting of the upper mantle as it upwells due to plate separation. Decades of research on active spreading ridges have led to a growing understanding of the complex magmatic, tectonic and hydrothermal processes linked to the formation of new oceanic igneous crust. However, less is known about the timescales of magmatic processes at mid-ocean ridges, including melting in and melt extraction from the mantle, fractional crystallisation, crustal assimilation and/or magma mixing. In this paper, we review the timescales of magmatic processes by integrating radiometric dating, chemical and petrological observations of mid-ocean ridge basalts (MORBs) and geophysical models. These different lines of evidence suggest that melt extraction and migration, and crystallisation and mixing processes occur over timescales of 1 to 10,000 a. High-resolution geochemical stratigraphic profiles of the oceanic crust using drill-core samples further show that at fast-spreading ridges, adjacent flow units may differ in age by only a few 100 a. We use existing chemical data and new major- and trace-element analyses of fresh MORB glasses from drill-cores in ancient Atlantic and Pacific crust, together with model stratigraphic ages to investigate how lava chemistry changes over 10 to 100 ka periods, the timescale of crustal accretion at spreading ridges which is recorded in the basalt stratigraphy in drilled sections through the oceanic crust. We show that drilled MORBs have compositions that are similar to those of young MORB glasses dredged from active spreading ridges (lavas that will eventually be preserved in the lowermost part of the extrusive section covered by younger flows), showing that the dredged samples are indeed representative of the bulk oceanic crust. Model stratigraphic ages calculated for individual flows in boreholes, together with the geochemical stratigraphy of the drilled sections, show that at

  18. Geology of Smooth Ridge: MARS-IODP Cabled Observatory Site

    NASA Astrophysics Data System (ADS)

    Jordahl, K. A.; Paull, C. K.; Ussler, W.; Aiello, I. W.; Mitts, P.; Greene, H. G.; Gibbs, S.

    2004-12-01

    We document the geologic environment of Smooth Ridge, off shore Central California, where the deep-water node associated with the MARS (Monterey Accelerated Research Site) scientific research cable is to be deployed. The MARS cable will provide internet connections and electric power at a node in 890 m of water in support of scientific observatory development and experiments. IODP boreholes are proposed which will be connected to the MARS cable. The deeply incised channels of Monterey and Soquel Canyons flank Smooth Ridge to the SW and NE and the San Gregorio faults marks its NW and upslope boundary. However, the top of Smooth Ridge, as its name implies, only has subdued bathymetric features. These include a subtle downslope channel and one distinct slump scar. A patch of acoustically reflective seafloor on the west side of the ridge, over 5 km from the MARS site, is associated with the only known large-scale biological community on the crest of Smooth Ridge. A reflection seismic survey conducted in 2003 with a high-resolution electrical sparker source reveals the stratigraphy of the Smooth Ridge in unprecedented detail. In conjunction with previously collected widely-spaced multichannnel seismic data, observations and samples obtained using remotely-operated vehicle (ROV) dives, and piston cores, this new survey reveals the erosional and depositional history of Smooth Ridge. The continuity of seismic reflections indicates nearly undisturbed deposition occurred until at least the mid-Miocene. Since that time, and especially since the upper Pliocene, the record is marked by unconformities and infill due to shifting channels, large slumps and landslides, and sediment waves. Several crossing seismic lines provide a quasi-three-dimensional view of a distinct slump scar's structure, and reveal a history of multiple headwall failures. Other subsurface structures, including a much larger, and older, slump feature, have no bathymetric expression at all. 14C dated piston

  19. Base cation controlled recovery from acidification in streams in the Ridge/Blue Ridge provinces

    NASA Astrophysics Data System (ADS)

    Robison, A.; Scanlon, T. M.; Cosby, B. J.; Webb, R.; Galloway, J. N.

    2012-12-01

    Widespread recovery of surface waters from acidification has been documented throughout the U.S. and Europe over recent decades with a notable exception being the Ridge/Blue Ridge province of the central Appalachians of the U.S. In this region, a decrease in sulfate deposition has not led to a similar decrease in surface water concentrations of this acid anion. Sixty four streams in western Virginia were sampled on a quarterly basis from 1987 to 2010 and were analyzed for various chemical and physical properties. We report here that while acidification continues for most systems, recovery, in terms of increasing acid neutralizing capacity (ANC), has begun to occur in the region on a limited basis. Over the timeframe of study, 33% of the streams demonstrated a positive trend in ANC. The status of watersheds with respect to acidification is controlled primarily by the availability of base cations derived from the underlying bedrock. Recovery was associated almost exclusively by watersheds underlain by relatively base-rich mafic and felsic bedrock, while continued acidification was dominated by sites with relatively base-poor siliciclastic and argillaceous bedrock. Further influencing recovery is the region's high soil sulfate adsorption capacity, a result of older, more highly weathered soils that were not impacted during the most recent glacial maxima. This factor is the main cause of the delayed response of watersheds to decreased acidic deposition. However, a mass balance analysis of sulfate at the base-poor White Oak Run watershed reveals export may soon surpass storage for the first time in the nearly three decades of continuous monitoring. Therefore, recovery from acidification may be near for the region's more ubiquitous base-poor watersheds, as steam sulfate concentrations are predicted to finally decrease. Our findings show a positive, albeit limited step in the recovery of this region from acidification and suggest that more widespread recovery could being

  20. Survey of protected vascular plants on the Oak Ridge Reservation, Oak Ridge, Tennessee

    SciTech Connect

    Awl, D.J.; Pounds, L.R.; Rosensteel, B.A.; King, A.L.; Hamlett, P.A.

    1996-06-01

    Vascular plant surveys were initiated during fiscal year 1992 by the environmentally sensitive areas program to determine the baseline condition of threatened and endangered (T&E) vascular plant species on the Oak Ridge Reservation (ORR). T&E species receive protection under federal and state regulations. In addition, the National Environmental Policy Act (NEPA) requires that federally-funded projects avoid or mitigate impacts to listed species. T&E plant species found on or near the U.S. Department of Energy`s (DOE) Oak Ridge Reservation (ORR) are identified. Twenty-eight species identified on the ORR are listed by the Tennessee Department of Environment and Conservation as either endangered, threatened, or of special concern. Four of these have been under review by the U.S. Fish and Wildlife Service for possible listing (listed in the formerly-used C2 candidate category). Additional species listed by the state occur near and may be present on the ORR. A range of habitats support the rare taxa on the ORR: river bluffs, sinkholes, calcareous barrens, wetlands, utility corridors, and forests. The list of T&E plant species and their locations on the ORR should be considered provisional because the entire ORR has not been surveyed, and state and federal status of all species continues to be updated. The purpose of this document is to present information on the listed T&E plant species currently known to occur on the ORR as well as listed species potentially occurring on the ORR based on geographic range and habitat availability. For the purpose of this report, {open_quotes}T&E species{close_quotes} include all federal- and state-listed species, including candidates for listing, and species of special concern. Consideration of T&E plant habitats is an important component of resource management and land-use planning; protection of rare species in their natural habitat is the best method of ensuring their long-term survival.

  1. Evidence of 60 meter deep Arctic pressure-ridge keels

    SciTech Connect

    Reimnitz, E.; Barnes, P.W.; Phillips, R.L.

    1985-11-01

    Numerous efforts have been made during the last two decades to determine the ice thickness distribution in the Arctic Ocean and in particular to learn the keel depth of the largest modern pressure ridges. With the discovery of oil and gas in the arctic offshore and the trend to extend exploration into deeper water and increasing distance from shore, knowledge of the maximum ice thickness in the continental shelf is becoming increasingly important. Various approaches have been used to directly obtain keel depth data in the Arctic, but no satisfactory technique for water depths of less than 100 meters exists. For continental shelves, virtually all public data on ridge keel configuration stems from spot measurements made with horizontally held sonar transducers lowered through the ice adjacent to ridges, and from cores of ridges. Because these techniques are time-consuming, the depths of only a few ridge keels have been determined by such methods. Fixed upward-looking sonar devices have been used with limited success in several applications to record under-ice relief and movement, but any data so obtained is not public. This report is an attempt to interpret the age of deepwater gouges seen on the Alaskan Arctic shelf.

  2. The negative gravity field over the 85 deg E ridge

    NASA Technical Reports Server (NTRS)

    Liu, C.-S.; Curray, J. R.; Sandwell, D. T.

    1982-01-01

    Two north-south ridges in the basement topography of the Bay of Bengal may be observed on an isopach map at 85 and at 90 deg E. Free-air gravity anomaly profiles across the region show a strong gravity low (about -60 mGal) over the 85 deg E ridge, and a gravity high over the other. Using a simple two-stage loading model, the negative gravity anomaly over the 85 deg E ridge is explained as a direct consequence of sediment loading, and the flexural rigidity of the lithosphere when the ridge was formed is estimated to have been about 180 times less than the flexural rigidity during the sediment loading. An approximate relationship between flexural rigidity and crustal age shows that the 85 deg E ridge was formed on relatively young lithosphere, 5-15 million years old, and that it was buried when the lithosphere was 40-80 million years old. The alteration of the gravity field by a thick layer of sediments may occur in other large sedimentary basins or along continental margins.

  3. Ancient, highly heterogeneous mantle beneath Gakkel ridge, Arctic Ocean.

    PubMed

    Liu, Chuan-Zhou; Snow, Jonathan E; Hellebrand, Eric; Brügmann, Gerhard; von der Handt, Anette; Büchl, Anette; Hofmann, Albrecht W

    2008-03-20

    The Earth's mantle beneath ocean ridges is widely thought to be depleted by previous melt extraction, but well homogenized by convective stirring. This inference of homogeneity has been complicated by the occurrence of portions enriched in incompatible elements. Here we show that some refractory abyssal peridotites from the ultraslow-spreading Gakkel ridge (Arctic Ocean) have very depleted 187Os/188Os ratios with model ages up to 2 billion years, implying the long-term preservation of refractory domains in the asthenospheric mantle rather than their erasure by mantle convection. The refractory domains would not be sampled by mid-ocean-ridge basalts because they contribute little to the genesis of magmas. We thus suggest that the upwelling mantle beneath mid-ocean ridges is highly heterogeneous, which makes it difficult to constrain its composition by mid-ocean-ridge basalts alone. Furthermore, the existence of ancient domains in oceanic mantle suggests that using osmium model ages to constrain the evolution of continental lithosphere should be approached with caution.

  4. The Sagatu Ridge dike swarm, Ethiopian rift margin. [tectonic evolution

    NASA Technical Reports Server (NTRS)

    Mohr, P. A.; Potter, E. C.

    1976-01-01

    A swarm of dikes forms the core of the Sagatu Ridge, a 70-km-long topographic feature elevated to more than 4000 m above sea level and 1500 m above the level of the Eastern (Somalian) plateau. The ridge trends NNE and lies about 50 km east of the northeasterly trending rift-valley margin. Intrusion of the dikes and buildup of the flood-lava pile, largely hawaiitic but with trachyte preponderant in the final stages, occurred during the late Pliocene-early Pleistocene and may have been contemporaneous with downwarping of the protorift trough to the west. The ensuing faulting that formed the present rift margin, however, bypassed the ridge. The peculiar situation and orientation of the Sagatu Ridge, and its temporary existence as a line of crustal extension and voluminous magmatism, are considered related to a powerful structural control by a major line of Precambrian crustal weakness, well exposed further south. Transverse rift structures of unknown type appear to have limited the development of the ridge to the north and south.

  5. Structural style and petroleum prospects of Tonga Ridge

    SciTech Connect

    Pflueger, J.; Havard, K.; Gatliff, R.; Helu, B.

    1989-03-01

    Recent reprocessing of seismic data from the Tonga Ridge has provided a clearer picture of the tectonic style of a forearc basin. Sediments along the ridge achieve a maximum thickness of more than 4000 m. Many faults have been observed, almost all of which are normal. The presence of scarps on the sea floor show that a significant percentage of the faults are active today. Although seismic transverses are not spaced closely enough to allow unambiguous definition of fault orientations, they believe that most of the tensional faults are parallel to the ridge axis. A second set of near-vertical faults with apparent transcurrent movement exists at a high angle to the ridge axis. Bathymetry has played a major role in defining the strikes of the second set of faults. The tensional failures are due to the flexing of the ridge as the leading edge of the Indo-Australian plate is pulled down and under by frictional attachment to the subducting Pacific plate. The development of major fault blocks is related to the subduction of Pacific plate seamounts. Fault-bounded closures and Eocene to Miocene reefs would form excellent traps for hydrocarbons. Oil seeps of biodegaded but thermally mature crude oil on the island of Tongatanu encouraged the drilling of five exploratory test wells, but the source rock feeding the seeps was not discovered. Burial history and geothermal modeling indicate that mature source rocks could occur deeper than depths penetrated by the test wells.

  6. The Mozambique Ridge: a document of massive multistage magmatism

    NASA Astrophysics Data System (ADS)

    Fischer, Maximilian D.; Uenzelmann-Neben, Gabriele; Jacques, Guillaume; Werner, Reinhard

    2017-01-01

    The Mozambique Ridge, a prominent basement high in the southwestern Indian Ocean, consists of four major geomorphological segments associated with numerous phases of volcanic activity in the Lower Cretaceous. The nature and origin of the Mozambique Ridge have been intensely debated with one hypothesis suggesting a Large Igneous Province origin. High-resolution seismic reflection data reveal a large number of extrusion centres with a random distribution throughout the southern Mozambique Ridge and the nearby Transkei Rise. Intrabasement reflections emerge from the extrusion centres and are interpreted to represent massive lava flow sequences. Such lava flow sequences are characteristic of eruptions leading to the formation of continental and oceanic flood basalt provinces, hence supporting a Large Igneous Province origin of the Mozambique Ridge. We observe evidence for widespread post-sedimentary magmatic activity that we correlate with a southward propagation of the East African Rift System. Based on our volumetric analysis of the southern Mozambique Ridge we infer a rapid sequential emplacement between ˜131 and ˜125 Ma, which is similar to the short formation periods of other Large Igneous Provinces like the Agulhas Plateau.

  7. Oak Ridge Y-12 Plant groundwater protection program management plan

    SciTech Connect

    1996-06-01

    The Oak Ridge Y- 1 2 Plant (Y-12 Plant) is owned by the United States Department of Energy (DOE) and managed by Lockheed Martin Energy Systems, Inc. (Energy Systems) under contract No. DE-AC05-84OR21400. The Y-12 Plant Groundwater Protection Program (GWPP), which was initiated in 1975, provides for the protection of groundwater resources consistent with Federal, State, and local regulations, and in accordance with DOE orders and Energy Systems policies and procedures. The Y-12 Plant is located in Anderson County, Tennessee, and is within the corporate limits of the City of Oak Ridge. The Y-12 Plant is one of three major DOE complexes that comprise the 37,000-acre Oak Ridge Reservation (ORR) located in Anderson and Roane counties. The Y-12 Plant is located in Bear Creek Valley at an elevation of about 950 feet (ft) above sea level. Bear Creek Valley is bounded on the northwest and southeast, and is isolated from populated areas of Oak Ridge, by parallel ridges that rise about 300 ft above the valley floor. The Y-12 Plant and its fenced buffer area are about 0.6 mile wide by 3.2 miles long and cover approximately 4,900 acres. The main industrialized section encompasses approximately 800 acres.

  8. Basalts dredged from the Amirante ridge, western Indian ocean

    USGS Publications Warehouse

    Fisher, R.L.; Engel, C.G.; Hilde, T.W.C.

    1968-01-01

    Oceanic tholeiitic basalts were dredged from 2500 to 3000 m depth on each flank of the Amirante Ridge, 1200 km southeast of Somalia in the western Indian Ocean, by R.V. Argo in 1964. One sample, probably shed from a flow or dike in basement beneath the coralline cap, gave a wholerock KAr age of 82??16??106 years. The age is similar to those reported by others for agglomerate from Providence Reef, nearer Madagascar, and for gabbro from Chain Ridge, the southwest member of Owen Fracture Zone, nearer the Somali coast. The Amirante Cretaceous-Early Tertiary occurrence lies between the "continental" 650 ?? 106 years granites of Seychelles Archipelago and the large Precambrian "continental" block of Madagascar. Trends of major structures and distribution of the related topographic and magnetic-anomaly lineations in 7-8 ?? 106 km2of the surrounding Indian Ocean suggest that in addition to spreading of the seafloor from the seismically-active Mid-Indian Ocean Ridge-Carlsberg Ridge complex there has been, since mid-Mesozoic time, distributed left-lateral shear along 52??-54??E that has moved Madagascar at least 700 km south relative to Seychelles Bank. Measurements by other indicate the absolute movement of Madagascar has been southward as well. The emplacement of oceanic tholeiitic basalts at shallow depth, the development of volcanic topography between the sedimented Somali and Mascarene basins, and the existence of the faulted Amirante Trench and Ridge are consequences of the displacement. ?? 1968.

  9. Where are the undiscovered hydrothermal vents on oceanic spreading ridges?

    NASA Astrophysics Data System (ADS)

    Beaulieu, Stace E.; Baker, Edward T.; German, Christopher R.

    2015-11-01

    In nearly four decades since the discovery of deep-sea vents, one-third of the length of global oceanic spreading ridges has been surveyed for hydrothermal activity. Active submarine vent fields are now known along the boundaries of 46 out of 52 recognized tectonic plates. Hydrothermal survey efforts over the most recent decade were sparked by national and commercial interests in the mineral resource potential of seafloor hydrothermal deposits, as well as by academic research. Here we incorporate recent data for back-arc spreading centers and ultraslow- and slow-spreading mid-ocean ridges (MORs) to revise a linear equation relating the frequency of vent fields along oceanic spreading ridges to spreading rate. We apply this equation globally to predict a total number of vent fields on spreading ridges, which suggests that ~900 vent fields remain to be discovered. Almost half of these undiscovered vent fields (comparable to the total of all vent fields discovered during 35 years of research) are likely to occur at MORs with full spreading rates less than 60 mm/yr. We then apply the equation regionally to predict where these hydrothermal vents may be discovered with respect to plate boundaries and national jurisdiction, with the majority expected to occur outside of states' exclusive economic zones. We hope that these predictions will prove useful to the community in the future, in helping to shape continuing ridge-crest exploration.

  10. Shallow subduction, ridge subduction, and the evolution of continental lithosphere

    SciTech Connect

    Helmstaedt, H.; Dixon, J.M.; Farrar, E.; Carmichael, D.M.

    1985-01-01

    Subduction of oceanic lithosphere beneath continental crust at a shallow angle has occurred throughout the Phanerozoic Eon. Ridge subduction often follows shallow subduction and causes bimodal volcanism and crustal rifting, forming back-arc basins. Recent models for Archean plate tectonics propose very fast rates of spreading (400-800 km/Ma) and convergence, and sinking rates comparable to or slower (<10 km/Ma) than those of today. As faster convergence and slower sinking correspond to subduction at shallower angles, shallow subduction and ridge subduction must have been ubiquitous during the Archean permobile regime. This is compatible with a back-arc-basin origin for Archean greenstone belts. The common coexistence of tholeiitic and calc-alkaline igneous rocks in Archean greenstone belts, also implies ridge subduction. The authors envisage a transition, between 2.4 and 1.8 Ga., from a regime dominated by shallow subduction and repeated ridge subduction to one of normal plate tectonics with steeper subduction. Spreading rates decreased; continental plates became larger and stable shelves could develop at trailing margins. Shallow subduction became the exception, restricted to episodes of abnormally fast convergence; nevertheless, the long span of post-Archean time makes it unlikely that any part of the continental crust has escaped shallow subduction and ridge subduction. These processes recycle much volatile-rich oceanic crust into the sub-continental upper mantle, thereby underplating the crust, effecting upper-mantle metasomatism and affecting intraplate magmatism.

  11. Topography and tectonics of mid-oceanic ridge axes

    NASA Technical Reports Server (NTRS)

    Sleep, N. H.; Rosendahl, B. R.

    1979-01-01

    Numerical fluid dynamic models of mid-oceanic ridge axes were constructed using distributions of material properties constrained by seismic studies and thermal calculations. The calculations indicate that spreading is passive except for forces caused by density differences due to thermal expansion and partial melt. Except for geometric differences due to temperature distribution, one set of mechanical properties can adequately explain central rifts of slow ridges and central peaks of fast ridges. Viscous head loss in the upwelling material dominates at low spreading rates where material ascends through a narrow conduit. Thermal expansion and partial melting dominate at high spreading rates where a wide low viscosity crustal magma chamber is present. The preferred rheology is 10 to the 20th poise for the upwelling lithosphere; less than 5 x 10 to the 17th for the crustal magma chamber and axial intrusion zone at fast ridges, and a yield stress of 200 bars for the lithosphere. The calculation correctly predicts the existence of central peaks at 'hot-spot' ridges, where seismic evidence indicates a large magma chamber.

  12. Seismicity prior to the 2016 Kumamoto earthquakes

    NASA Astrophysics Data System (ADS)

    Nanjo, Kazuyoshi Z.; Izutsu, Jun; Orihara, Yoshiaki; Furuse, Nobuhiro; Togo, Shoho; Nitta, Hidetoshi; Okada, Tomohiro; Tanaka, Rika; Kamogawa, Masashi; Nagao, Toshiyasu

    2016-11-01

    We report precursory seismic patterns prior to the 2016 Kumamoto earthquakes, as measured by four different methods based on changes in seismicity that can be used for earthquake forecasting: the b-value method, two methods of seismic quiescence evaluation, and an analysis of seismicity density in space and time. The spatial extent of precursory patterns differs from one method to the other and ranges from local scales (typically, asperity size) to regional scales (e.g., 2° × 3° around the source zone). The earthquakes were preceded by periods of pronounced anomalies, which lasted in yearly scales (1.5 years), or longer (>3 years). We demonstrate that a combination of multiple methods detected different signals prior to the Kumamoto earthquakes. This indicates great potential to reduce the hazard at possible future sites of earthquakes relative to long-term seismic hazard assessment. We also found that the seismic quiescence in a regional-scale area, detected by using the two methods of seismic quiescence evaluation, was a common precursor to the 2016 Kumamoto earthquakes and 2015 Off Satsuma Peninsula earthquake. The result allows us to interpret both events as the onset that occurred at a section along the tectonic line from the Okinawa Trough through the Beppu-Shimabara graben.[Figure not available: see fulltext.

  13. IMPROVED PHOTOMETRIC REDSHIFTS WITH SURFACE LUMINOSITY PRIORS

    SciTech Connect

    Xia Lifang; Cohen, Seth; Malhotra, Sangeeta; Rhoads, James; Grogin, Norman; Windhorst, Rogier A.; Hathi, Nimish P.; Pirzkal, Nor; Xu Chun

    2009-07-15

    We apply Bayesian statistics with prior probabilities of galaxy surface luminosity (SL) to improve photometric redshifts. We apply the method to a sample of 1266 galaxies with spectroscopic redshifts in the GOODS North and South fields at 0.1 {approx}< z {approx}< 2.0. We start with spectrophotometric redshifts (SPZs) based on Probing Evolution and Reionization Spectroscopically grism spectra, which cover a wavelength range of 6000-9000 A, combined with (U)BViz(JHK) broadband photometry in the GOODS fields. The accuracy of SPZ redshifts is estimated to be {sigma}({delta}(z)) = 0.035 with an systematic offset of -0.026, where {delta}(z) = {delta}z/(1 + z), for galaxies in redshift range of 0.5 {approx}< z {approx}< 1.25. The addition of the SL prior probability helps break the degeneracy of SPZ redshifts between low redshift 4000 A break galaxies and high-redshift Lyman break galaxies which are mostly catastrophic outliers. For the 1138 galaxies at z {approx}< 1.6, the fraction of galaxies with redshift deviation {delta}(z)>0.2 is reduced from 15.0% to 10.4%, while the rms scatter of the fractional redshift error does not change much.

  14. Prior knowledge-based approach for associating ...

    EPA Pesticide Factsheets

    Evaluating the potential human health and/or ecological risks associated with exposures to complex chemical mixtures in the ambient environment is one of the central challenges of chemical safety assessment and environmental protection. There is a need for approaches that can help to integrate chemical monitoring and bio-effects data to evaluate risks associated with chemicals present in the environment. We used prior knowledge about chemical-gene interactions to develop a knowledge assembly model for detected chemicals at five locations near two wastewater treatment plants. The assembly model was used to generate hypotheses about the biological impacts of the chemicals at each location. The hypotheses were tested using empirical hepatic gene expression data from fathead minnows exposed for 12 d at each location. Empirical gene expression data was also mapped to the assembly models to statistically evaluate the likelihood of a chemical contributing to the observed biological responses. The prior knowledge approach was able reasonably hypothesize the biological impacts at one site but not the other. Chemicals most likely contributing to the observed biological responses were identified at each location. Despite limitations to the approach, knowledge assembly models have strong potential for associating chemical occurrence with potential biological effects and providing a foundation for hypothesis generation to guide research and/or monitoring efforts relat

  15. Incorporating prior information into association studies

    PubMed Central

    Darnell, Gregory; Duong, Dat; Han, Buhm; Eskin, Eleazar

    2012-01-01

    Summary: Recent technological developments in measuring genetic variation have ushered in an era of genome-wide association studies which have discovered many genes involved in human disease. Current methods to perform association studies collect genetic information and compare the frequency of variants in individuals with and without the disease. Standard approaches do not take into account any information on whether or not a given variant is likely to have an effect on the disease. We propose a novel method for computing an association statistic which takes into account prior information. Our method improves both power and resolution by 8% and 27%, respectively, over traditional methods for performing association studies when applied to simulations using the HapMap data. Advantages of our method are that it is as simple to apply to association studies as standard methods, the results of the method are interpretable as the method reports p-values, and the method is optimal in its use of prior information in regards to statistical power. Availability: The method presented herein is available at http://masa.cs.ucla.edu Contact: eeskin@cs.ucla.edu PMID:22689754

  16. Dermal digital ridge density of a penal population: Analysis of association and individualization.

    PubMed

    Kaur, Maninder; Sharma, Krishan

    2016-11-01

    The present study is an attempt to analyze an association between dermal digital ridge density and explosive personality based on the study of 100 male prisoners and 50 controls. The control group had higher ridge density than the prisoners. Bilateral differences revealed higher ridge density on left hand than right hand in both the groups, but differences between two groups for directional asymmetry were not significant. Surface area is not correlated with ridge density in all the digits. About 50% of the variation in ridge density may be explained by a single factor which in all probability is the genetic component of variation. Ridge density cannot be used as a marker for assessing individual's height. Individuals having ridge density less than 12 ridges and higher than 15 ridges, i.e. placed on the two extremes were more likely than not to have more explosive personality.

  17. Effect of longitudinal ridges on the hydrodynamic performance of a leatherback turtle model

    NASA Astrophysics Data System (ADS)

    Bang, Kyeongtae; Kim, Jooha; Lee, Sang-Im; Choi, Haecheon

    2014-11-01

    Leatherback sea turtles (Dermochelys coriacea) known as the fastest swimmer and the deepest diver among marine turtles have five longitudinal ridges on their carapace, and these ridges are the most remarkable morphological features distinguished from other marine turtles. To investigate the effect of these ridges on the hydrodynamic performance of the leatherback turtle, we model a carapace with and without ridges using a stuffed leatherback turtle in the National Science Museum, Korea. We measure the drag and lift forces on the ridged model in the ranges of real leatherback turtles' Reynolds number (Re) and angle of attack (α), and compare them with those of non-ridged model. At α < 6°, longitudinal ridges decrease drag on the ridged model by up to 32% compared to non-ridged model. On the other hand, at α > 6°, the drag and lift coefficients of the ridged model are higher than those of the non-ridged model, and the lift-to-drag ratio of the ridged model is higher by about 7% than that of the non-ridged model. We also measure the velocity field around both models using a particle image velocimetry and explain the hydrodynamic role of ridges in relation to diving behaviors of leatherback sea turtles. Supported by the NRF Program (2011-0028032).

  18. Geochemical constraints on the formation of near-ridge Vance seamount chain at the Juan de Fuca Ridge (Invited)

    NASA Astrophysics Data System (ADS)

    Walters, R. L.; Hann, N.; Perfit, M. R.

    2013-12-01

    Observations and sampling of off-axis lava flows and near-ridge seamounts, coupled with the recent discovery of large melt bodies away from ridge axes, attest to the significance of off-axis magmatic phenomena for the formation of the oceanic lithosphere at mid-ocean ridges (MORs). One of the most crucial unsolved questions of oceanic volcanism surrounds the physical mantle processes that cause the initial formation of near-ridge seamounts and sustain volcanism over several million years to produce seamount chains. The Vance Seamounts are just one example of a series of near-ridge seamount chains on the Pacific Plate. The chain comprises six submarine mountains that sit more than 1km above the surrounding oceanic crust just west of the Vance segment of the Juan de Fuca Ridge (JdFR). Dive observations indicate that the seamount chain formed sequentially with the oldest seamount furthest from the ridge axis. The geochemical characteristics of the oldest seamount suggest that the initiation of seamount volcanism was associated with a localized chemical (× thermal) heterogeneity in the mantle. Trace element and isotopic signatures suggest that the chemical heterogeneity was progressively depleted as subsequent seamounts were formed. Central seamount lavas have N-MORB compositions with trace element and isotopic ratios that are significantly more depleted than N-MORB lavas erupted at the JdFR axis. Depletion in the most incompatible elements is so severe for the central seamounts that no physically realistic forward geochemical models involving average depleted MORB mantle can reproduce potential parental melt compositions. The lava compositions from seamounts closest to the ridge reverse the trend in trace element depletion becoming more similar to N-MORB erupted at the current axis. We suggest that excess melt is generated off-axis due to the impingement of a discrete chemical heterogeneity that is more fusible than the DMM matrix. A variety of 2D model ridge

  19. Hybrid on-axis plus ridge-perpendicular circulation reconciles hydrothermal flow observations at fast spreading ridges

    NASA Astrophysics Data System (ADS)

    Hasenclever, J.; Theissen-Krah, S.; Rupke, L.; Morgan, J.; Iyer, K. H.; Petersen, S.; Devey, C. W.

    2013-12-01

    We present crustal-scale 3D numerical calculations of hydrothermal fluid flow at fast spreading ridges. The model domain covers 5 km along-axis, 20 km across-axis and extends down to Moho depth. We observe that a complex hydrothermal system develops that extends over the entire crustal thickness and forms a series of on-axis vent fields with an average along-ridge spacing of 500-1000m. This hydrothermal system comprises two distinct flow components: (1) An on-axis circulation above the melt lens with recharging flow surrounding the hot up-flow zones. (2) A ridge-perpendicular circulation with recharge areas located kilometers away from the ridge. Here fluids penetrate the crust down to Moho depth and travel at temperatures of 400-600°C towards the ridge where they merge with the on-axis circulation in a reaction zone above the axial melt lens. Fluids released at the seafloor are a mixture of both components, with an average ratio between proximately- and distally-sourced fluids of about 2:1. This hybrid hydrothermal system reconciles previously incompatible observations that support either on-axis or ridge-perpendicular circulation patterns. The potential co-existence of two interacting hydrothermal circulations at fast spreading ridges is of importance for the interpretation of chemical signatures at hydrothermal vents and the quantification of the mass and energy exchange between ocean and solid earth: (1) A vertically and laterally extended ridge-perpendicular circulation will expose a much larger volume of oceanic crust to high-temperature hydrothermal alteration. Especially the lower crust would also be exposed to significant hydrothermal fluid flow and thus geochemical mining. (2) Fluids that migrate ridge-perpendicular and undergo phase separation at depth are likely to separate gravitationally from the denser and highly saline brine phase. Only the vapor-like phase may migrate up-slope towards the top of the melt lens, where these fluids would provide a

  20. Droplets move over viscoelastic substrates by surfing a ridge

    PubMed Central

    Karpitschka, S.; Das, S.; van Gorcum, M.; Perrin, H.; Andreotti, B.; Snoeijer, J. H.

    2015-01-01

    Liquid drops on soft solids generate strong deformations below the contact line, resulting from a balance of capillary and elastic forces. The movement of these drops may cause strong, potentially singular dissipation in the soft solid. Here we show that a drop on a soft substrate moves by surfing a ridge: the initially flat solid surface is deformed into a sharp ridge whose orientation angle depends on the contact line velocity. We measure this angle for water on a silicone gel and develop a theory based on the substrate rheology. We quantitatively recover the dynamic contact angle and provide a mechanism for stick–slip motion when a drop is forced strongly: the contact line depins and slides down the wetting ridge, forming a new one after a transient. We anticipate that our theory will have implications in problems such as self-organization of cell tissues or the design of capillarity-based microrheometers. PMID:26238436

  1. Merkel cells and the individuality of friction ridge skin.

    PubMed

    Kücken, Michael; Champod, Christophe

    2013-01-21

    There is no definite theory yet for the mechanism by which the pattern of epidermal ridges on fingers, palms and soles forming friction ridge skin (FRS) patterns is created. For a long time growth forces in the embryonal epidermis have been believed to be involved in FRS formation. More recent evidence suggests that Merkel cells play an important part in this process as well. Here we suggest a model for the formation of FRS patterns that links Merkel cells to the epidermal stress distribution. The Merkel cells are modeled as agents in an agent based model that move anisotropically where the anisotropy is created by the epidermal stress tensor. As a result ridge patterns are created with pattern defects as they occur in real FRS patterns. As a consequence we suggest why the topology of FRS patterns is indeed unique as the arrangement of pattern defects is sensitive to the initial configuration of Merkel cells.

  2. Contaminated scrap metal management on the Oak Ridge Reservation

    SciTech Connect

    Hayden, H.W.; Stephenson, M.J.; Bailey, J.K.; Weir, J.R.; Gilbert, W.C.

    1993-09-01

    Large quantities of scrap metal are accumulating at the various Department of Energy (DOE) installations across the country as a result of ongoing DOE programs and missions in concert with present day waste management practices. DOE Oak Ridge alone is presently storing around 500,000 tons of scrap metal. The local generation rate, currently estimated at 1,400 tons/yr, is expected to increase sharply over the next couple of years as numerous environmental restoration and decommissioning programs gain momentum. Projections show that 775,000 tons of scrap metal could be generated at the K-25 Site over the next ten years. The Y-12 Plant and Oak Ridge National Laboratory (ORNL) have similar potentials. The history of scrap metal management at Oak Ridge and future challenges and opportunities are discussed.

  3. InP-based deep-ridge NPN transistor laser

    NASA Astrophysics Data System (ADS)

    Liang, S.; Kong, D. H.; Zhu, H. L.; Zhao, L. J.; Pan, J. Q.; Wang, W.

    2011-08-01

    We report an InP-based deep-ridge NPN transistor laser (TL, λ˜1.5μm). By placing the quantum well (QW) active material above the heavily Zn-doped base layer, both the optical absorption of the heavily p-doped base material and the damage of the quality of the QWs resulted from the Zn diffusion into the QWs are decreased greatly. CW operation of the TL is achieved at -40°C, which is much better than the shallow-ridge InP-based NPN TL. With future optimization of the growth procedure, significant improvement of the performance of the deep-ridge InP-based NPN TLs is expected.

  4. InP-based deep-ridge NPN transistor laser.

    PubMed

    Liang, S; Kong, D H; Zhu, H L; Zhao, L J; Pan, J Q; Wang, W

    2011-08-15

    We report an InP-based deep-ridge NPN transistor laser (TL, λ∼1.5 μm). By placing the quantum well (QW) active material above the heavily Zn-doped base layer, both the optical absorption of the heavily p-doped base material and the damage of the quality of the QWs resulted from the Zn diffusion into the QWs are decreased greatly. CW operation of the TL is achieved at -40 °C, which is much better than the shallow-ridge InP-based NPN TL. With future optimization of the growth procedure, significant improvement of the performance of the deep-ridge InP-based NPN TLs is expected.

  5. Modes of faulting at mid-ocean ridges.

    PubMed

    Buck, W Roger; Lavier, Luc L; Poliakov, Alexei N B

    2005-04-07

    Abyssal-hill-bounding faults that pervade the oceanic crust are the most common tectonic feature on the surface of the Earth. The recognition that these faults form at plate spreading centres came with the plate tectonic revolution. Recent observations reveal a large range of fault sizes and orientations; numerical models of plate separation, dyke intrusion and faulting require at least two distinct mechanisms of fault formation at ridges to explain these observations. Plate unbending with distance from the top of an axial high reproduces the observed dip directions and offsets of faults formed at fast-spreading centres. Conversely, plate stretching, with differing amounts of constant-rate magmatic dyke intrusion, can explain the great variety of fault offset seen at slow-spreading ridges. Very-large-offset normal faults only form when about half the plate separation at a ridge is accommodated by dyke intrusion.

  6. Droplets move over viscoelastic substrates by surfing a ridge

    NASA Astrophysics Data System (ADS)

    Karpitschka, S.; Das, S.; van Gorcum, M.; Perrin, H.; Andreotti, B.; Snoeijer, J. H.

    2015-08-01

    Liquid drops on soft solids generate strong deformations below the contact line, resulting from a balance of capillary and elastic forces. The movement of these drops may cause strong, potentially singular dissipation in the soft solid. Here we show that a drop on a soft substrate moves by surfing a ridge: the initially flat solid surface is deformed into a sharp ridge whose orientation angle depends on the contact line velocity. We measure this angle for water on a silicone gel and develop a theory based on the substrate rheology. We quantitatively recover the dynamic contact angle and provide a mechanism for stick-slip motion when a drop is forced strongly: the contact line depins and slides down the wetting ridge, forming a new one after a transient. We anticipate that our theory will have implications in problems such as self-organization of cell tissues or the design of capillarity-based microrheometers.

  7. The Oak Ridge Reservation Annual Site Environmental Report, 2007

    SciTech Connect

    Hughes, Joan; Thompson, Sharon; Page, David

    2008-09-30

    The Oak Ridge Reservation (ORR) consists of three major government-owned, contractor-operated facilities: the Y-12 National Security Complex, Oak Ridge National Laboratory, and East Tennessee Technology Park. The ORR was established in the early 1940s as part of the Manhattan Project, a secret undertaking that produced materials for the first atomic bombs. The reservation’s role has evolved over the years, and it continues to adapt to meet the changing defense, energy, and research needs of the United States. Both the work carried out for the war effort and subsequent research, development, and production activities have involved, and continue to involve, the use of radiological and hazardous materials. The Oak Ridge Reservation Annual Site Environmental Report and supporting data are available at Http://www.ornl.gov/sci/env_rpt or from the project director.

  8. Droplets move over viscoelastic substrates by surfing a ridge.

    PubMed

    Karpitschka, S; Das, S; van Gorcum, M; Perrin, H; Andreotti, B; Snoeijer, J H

    2015-08-04

    Liquid drops on soft solids generate strong deformations below the contact line, resulting from a balance of capillary and elastic forces. The movement of these drops may cause strong, potentially singular dissipation in the soft solid. Here we show that a drop on a soft substrate moves by surfing a ridge: the initially flat solid surface is deformed into a sharp ridge whose orientation angle depends on the contact line velocity. We measure this angle for water on a silicone gel and develop a theory based on the substrate rheology. We quantitatively recover the dynamic contact angle and provide a mechanism for stick-slip motion when a drop is forced strongly: the contact line depins and slides down the wetting ridge, forming a new one after a transient. We anticipate that our theory will have implications in problems such as self-organization of cell tissues or the design of capillarity-based microrheometers.

  9. Composition of basalts from the Mid-Atlantic Ridge

    USGS Publications Warehouse

    Engel, A.E.J.; Engel, C.G.

    1964-01-01

    Studies of volcanic rocks in dredge hauls from the submerged parts of the Mid-Atlantic Ridge suggest that it consists largely of tholeiitic basalt with low values of K, Ti, and P. In contrast, the volcanic islands which form the elevated caps on the Ridge are built of alkali basalt with high values of Ti, Fe3+, P, Na, and K. This distinct correlation between the form of the volcanic structures, elevation above the sea floor, and composition suggests that the islands of alkali basalt are derived from a parent tholeiitic magma by differentiation in shallow reservoirs. The volume of low-potassium tholeiites along the Mid-Atlantic Ridge and elsewhere in the oceans appears to be many times that of the alkali basalts exposed on oceanic islands. Tholeiitic basalts with about 0.2 K2O appear to be the primary and predominant magma erupted on the oceanic floor.

  10. How did the equatorial ridge on Saturn's moon Iapetus form?

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-04-01

    Saturn's moon Iapetus is one of the most unusual moons in our solar system. Perhaps the most bizarre feature of Iapetus is its equatorial ridge, a 20-kilometer-high, 200-kilometer-wide mountain range that runs exactly along the equator, circling more than 75% of the moon. No other body in the solar system exhibits such a feature; as Dombard et al. show, previous models have been unable to adequately explain how the ridge formed. The authors propose that the ridge formed from an ancient giant impact that produced a subsatellite around Iapetus. Tidal interactions with Iapetus ultimately led to orbital decay, eventually bringing the subsatellite close enough that the same forces tore it apart, forming a debris ring around Iapetus. Material from this debris ring then rained down on Iapetus, the researchers say, creating the mountain ring along the equator. (Journal of Geophysical Research-Planets, doi:10.1029/2011JE004010, 2012)

  11. Hydrothermal activity at the Trans-Atlantic Geotraverse Hydrothermal Field, Mid-Atlantic Ridge crest at 26°N

    NASA Astrophysics Data System (ADS)

    Rona, P. A.; Thompson, G.; Mottl, M. J.; Karson, J. A.; Jenkins, W. J.; Graham, D.; Mallette, M.; von Damm, K.; Edmond, J. M.

    1984-12-01

    The first submersible observations of the only known active submarine hydrothermal field on a slow-spreading oceanic ridge are incorporated with results of 10 prior years of investigation to derive an understanding of periodicity, duration, and varying intensity of hydrothermal activity at the Trans-Atlantic Geotraverse (TAG) Hydrothermal Field on the Mid-Atlantic Ridge crest near latitude 26°N. Hydrothermal activity has persisted at this location for at least 1×106 years based on the distribution of hydrothermal and hydrogenous mineralization with respect to crustal age. The hydrothermal activity has been cyclic, multistage, and episodic. Prior high-temperature hydrothermal venting stages with a periodicity of the order of 1×104 years and duration of the order of 101 years are deduced from the estimated ages of discrete sedimentary layers anomalously enriched in Cu, Fe, and Zn and correspond with the independently determined periodicity of volcanic eruptive cycles on the Mid-Atlantic Ridge. The most recent episode of high-temperature venting is inferred to have ceased in the recent past based on metal enrichment (Cu, Fe, Zn) in the surficial sediment layer. Low-temperature hydrothermal venting stages with a duration of the order of 1×104 years intervene between the short high-temperature stages and produce stratiform deposits of layered and earthy manganese oxide, iron oxide, hydroxide, and silicate. Bivalve-like forms with the characteristics of vent clams in various stages of dissolution are identified on bottom photographs. The fresh appearance of intact tubules composed of iron hydroxide that acted as vents on relict deposits, conductive heat flow anomalies in the sediment column, and the record of temperature anomalies and excess 3He in the near-bottom water column, suggest that the low-temperature hydrothermal discharge is intermittent at individual vents on a time scale of years.

  12. Hot spot-ridge crest convergence in the northeast Pacific

    SciTech Connect

    Karsten, J.L.; Delaney, J.R. )

    1989-01-10

    Evolution of the Juan de Fuca Ridge during the past 7 m.y. has been reconstructed taking into account both the propagating rift history and migration of the spreading center in the 'absolute' (fixed hot spot) reference frame. Northwestward migration of the spreading center (at a rate of 30 km/m.y.) has resulted in progressive encroachment of the ridge axis on the Cobb Hot Spot and westward jumping of the central third of the ridge axis more recently than 0.5 Ma. Seamounts in the Cobb-Eickelberg chain are predicted to display systematic variations in morphology and petrology, and a reduction in the age contrast between the edifice and underlying crust, as a result of the ridge axis approach. Relative seamount volumes also indicate that magmatic output of the hot spot varied during this interval, with a reduction in activity between 2.5 and 4.5 Ma, compared with relatively more robust activity before and after this period. Spatial relationships determined in this reconstruction allow hypotheses relating hot spot activity and rift propagation to be evaluated. In most cases, rift propagation has been directed away from the hot spot during the time period considered. Individual propagators show some reduction in propagation rate as separation between the propagating rift tip and hot spot increases, but cross comparison of multiple propagators does not uniformly display the same relationship. No obvious correlation exists between propagation rate and increasing proximity of the hot spot to the ridge axis or increasing hot spot output. Taken together, these observations do not offer compelling support for the concept of hot spot driven rift propagation. However, short-term reversals in propagation direction at the Cobb Offset coincide with activity of the Heckle melting anomaly, suggesting that local propagation effects may be related to excess magma supply at the ridge axis.

  13. Pesticide Leaching from Agricultural Fields with Ridges and Furrows

    PubMed Central

    Boesten, Jos J. T. I.

    2010-01-01

    In the evaluation of the risk of pesticide leaching to groundwater, the soil surface is usually assumed to be level, although important crops like potato are grown on ridges. A fraction of the water from rainfall and sprinkler irrigation may flow along the soil surface from the ridges to the furrows, thus bringing about an extra load of water and pesticide on the furrow soil. A survey of the literature reveals that surface-runoff from ridges to furrows is a well-known phenomenon but that hardly any data are available on the quantities of water and pesticide involved. On the basis of a field experiment with additional sprinkler irrigation, computer simulations were carried out with the Pesticide Emission Assessment at Regional and Local scales model for separate ridge and furrow systems in a humic sandy potato field. Breakthrough curves of bromide ion (as a tracer for water flow) and carbofuran (as example pesticide) were calculated for 1-m depth in the field. Bromide ion leached comparatively fast from the furrow system, while leaching from the ridge system was slower showing a maximum concentration of about half of that for the furrow system. Carbofuran breakthrough from the furrow system began about a month after application and increased steadily to substantial concentrations. Because the transport time of carbofuran in the ridge soil was much longer, no breakthrough occurred in the growing season. The maximum concentration of carbofuran leaching from the ridge–furrow field was computed to be a factor of six times as high as that computed for the corresponding level field. The study shows that the risk of leaching of pesticides via the furrow soil can be substantially higher than that via the corresponding level field soil. PMID:21076668

  14. Improving semantic scene understanding using prior information

    NASA Astrophysics Data System (ADS)

    Laddha, Ankit; Hebert, Martial

    2016-05-01

    Perception for ground robot mobility requires automatic generation of descriptions of the robot's surroundings from sensor input (cameras, LADARs, etc.). Effective techniques for scene understanding have been developed, but they are generally purely bottom-up in that they rely entirely on classifying features from the input data based on learned models. In fact, perception systems for ground robots have a lot of information at their disposal from knowledge about the domain and the task. For example, a robot in urban environments might have access to approximate maps that can guide the scene interpretation process. In this paper, we explore practical ways to combine such prior information with state of the art scene understanding approaches.

  15. Prior expectations facilitate metacognition for perceptual decision.

    PubMed

    Sherman, M T; Seth, A K; Barrett, A B; Kanai, R

    2015-09-01

    The influential framework of 'predictive processing' suggests that prior probabilistic expectations influence, or even constitute, perceptual contents. This notion is evidenced by the facilitation of low-level perceptual processing by expectations. However, whether expectations can facilitate high-level components of perception remains unclear. We addressed this question by considering the influence of expectations on perceptual metacognition. To isolate the effects of expectation from those of attention we used a novel factorial design: expectation was manipulated by changing the probability that a Gabor target would be presented; attention was manipulated by instructing participants to perform or ignore a concurrent visual search task. We found that, independently of attention, metacognition improved when yes/no responses were congruent with expectations of target presence/absence. Results were modeled under a novel Bayesian signal detection theoretic framework which integrates bottom-up signal propagation with top-down influences, to provide a unified description of the mechanisms underlying perceptual decision and metacognition.

  16. Prolonged instability prior to a regime shift.

    PubMed

    Spanbauer, Trisha L; Allen, Craig R; Angeler, David G; Eason, Tarsha; Fritz, Sherilyn C; Garmestani, Ahjond S; Nash, Kirsty L; Stone, Jeffery R

    2014-01-01

    Regime shifts are generally defined as the point of 'abrupt' change in the state of a system. However, a seemingly abrupt transition can be the product of a system reorganization that has been ongoing much longer than is evident in statistical analysis of a single component of the system. Using both univariate and multivariate statistical methods, we tested a long-term high-resolution paleoecological dataset with a known change in species assemblage for a regime shift. Analysis of this dataset with Fisher Information and multivariate time series modeling showed that there was a∼2000 year period of instability prior to the regime shift. This period of instability and the subsequent regime shift coincide with regional climate change, indicating that the system is undergoing extrinsic forcing. Paleoecological records offer a unique opportunity to test tools for the detection of thresholds and stable-states, and thus to examine the long-term stability of ecosystems over periods of multiple millennia.

  17. Least Squares Estimation Without Priors or Supervision

    PubMed Central

    Raphan, Martin; Simoncelli, Eero P.

    2011-01-01

    Selection of an optimal estimator typically relies on either supervised training samples (pairs of measurements and their associated true values) or a prior probability model for the true values. Here, we consider the problem of obtaining a least squares estimator given a measurement process with known statistics (i.e., a likelihood function) and a set of unsupervised measurements, each arising from a corresponding true value drawn randomly from an unknown distribution. We develop a general expression for a nonparametric empirical Bayes least squares (NEBLS) estimator, which expresses the optimal least squares estimator in terms of the measurement density, with no explicit reference to the unknown (prior) density. We study the conditions under which such estimators exist and derive specific forms for a variety of different measurement processes. We further show that each of these NEBLS estimators may be used to express the mean squared estimation error as an expectation over the measurement density alone, thus generalizing Stein’s unbiased risk estimator (SURE), which provides such an expression for the additive gaussian noise case. This error expression may then be optimized over noisy measurement samples, in the absence of supervised training data, yielding a generalized SURE-optimized parametric least squares (SURE2PLS) estimator. In the special case of a linear parameterization (i.e., a sum of nonlinear kernel functions), the objective function is quadratic, and we derive an incremental form for learning this estimator from data. We also show that combining the NEBLS form with its corresponding generalized SURE expression produces a generalization of the score-matching procedure for parametric density estimation. Finally, we have implemented several examples of such estimators, and we show that their performance is comparable to their optimal Bayesian or supervised regression counterparts for moderate to large amounts of data. PMID:21105827

  18. Sr isotopic variations along the Juan de Fuca Ridge.

    USGS Publications Warehouse

    Eaby, J.; Clague, D.A.; Delaney, J.R.

    1984-01-01

    The Sr isotopic ratios of 39 glass and microcrystalline basalt samples along the Juan de Fuca Ridge and one glass sample from Brown Bear Seamount are at the lower end of the range for normal MORB; the average 87Sr/86Sr ratio is 0.70249 + or - 0.00014 (2sigma ). Although subtle variations exist along the strike of the ridge, the Sr isotopic data do not show systematic variation relative to the proposed Cobb hotspot. The isotopic data are inconsistent with an enriched mantle-plume origin for the Cobb-Eikelberg Seamount chain.-W.H.B.

  19. Transient Hotspot Motion Induced by Plume-Migrating Ridge Interaction

    NASA Astrophysics Data System (ADS)

    Hall, P. S.; Farahat, N. X.; Kundargi, R.

    2013-12-01

    Paleomagnetic data obtained from the Emperor Seamount Chain shows that the Hawaiian hotspot moved rapidly (~40 mm/yr) southward relative to the Earth's magnetic poles during the period of 81- 47 Ma before coming to rest at its present latitude, suggesting that this abrupt change in the motion of the hotspot created the prominent bend in the Hawaii-Emperor Seamount Chain (HESC) [Tarduno et al., 2003]. Tarduno et al. [2009] proposed that this period of rapid hotspot motion might have been the surface expression of the conduit of the presumed Hawaiian plume being entrained and tilted by the passage of a migrating mid-ocean ridge (the Pacific-Kula ridge system) over the plume. While geophysical and geochemical observations have suggested that ridges can influence the dispersion of plumes in the upper mantle at great distances (>1000 km), much about the interaction between mantle plumes and mid-ocean ridges remains poorly understood. We report on a series of 2-D numerical and 3-D analog geodynamic experiments in which a mid-ocean ridge migrates over a mantle plume. These experiments were undertaken to characterize variations in the location of plume-derived melt as the system evolves through time. A range of values for plume excess temperature, plume conduit width, spreading rate and ridge migration rate were investigated so as to fully evaluate the behavior of the system. We find that both the location of the maximum flux of plume-derived melt and the total area over which plume melt is generated vary systemically over the course of the experiments. Most notably, as the ridge moves away from the plume conduit, the area from which plume-derived melts are generated gradually expands in the direction of ridge migration until it reaches a maximum extent, after which it rapidly collapses back towards the plume conduit. The edge of this zone of plume-derived melting can extend as much as 1500 km from the plume conduit, and upon reaching its maximum extent it retreats towards

  20. Using ridge regression in systematic pointing error corrections

    NASA Technical Reports Server (NTRS)

    Guiar, C. N.

    1988-01-01

    A pointing error model is used in the antenna calibration process. Data from spacecraft or radio star observations are used to determine the parameters in the model. However, the regression variables are not truly independent, displaying a condition known as multicollinearity. Ridge regression, a biased estimation technique, is used to combat the multicollinearity problem. Two data sets pertaining to Voyager 1 spacecraft tracking (days 105 and 106 of 1987) were analyzed using both linear least squares and ridge regression methods. The advantages and limitations of employing the technique are presented. The problem is not yet fully resolved.

  1. Surface radiological investigation of Trench 5 in Waste Area Grouping 7 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Goff, D.D.

    1991-08-01

    A surface radiological investigation of areas encompassing Trench 5 on the Oak Ridge Reservation (ORR) was conducted from May 1990 through November 1990. This survey was led by the author, assisted by various members of the Measurement Applications and Development (MAD) group of the Health and Safety Research Division (HASRD) of Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee. The purpose of the investigation was to determine the presence, nature, and extent of surface radiological contamination at Trench 5, the Homogeneous Reactor Experiment fuel wells, and surrounding areas. Based on the data obtained in the field, interim corrective measures were recommended to limit human exposure to radioactivity and to minimize insult to the environment. It should be stressed that this project was not intended to be a complete site characterization but rather to be a preliminary investigation into the potential contamination problem that might exist as a result of past operations at Trench 5.

  2. Calendar year 1994 groundwater quality report for the Chestnut Ridge Hydrogeologic Regime, Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1995-09-01

    This groundwater quality report (GWQR) contains an evaluation of the groundwater quality data obtained during the 1994 calendar year (CY) at several hazardous and non-hazardous waste management facilities associated with the US Department of Energy (DOE) Y-12 Plant located on the DOE Oak Ridge Reservation (ORR) southeast of Oak Ridge, Tennessee (Figure 1). These sites lie within the boundaries of the Chestnut Ridge Hydrogeologic Regime (Chestnut Ridge Regime), which is one of three hydrogeologic regimes defined for the purposes of groundwater quality monitoring at the Y-12 Plant (Figure 2). The Environmental Management Department of the Y-12 Plant Health, Safety, Environment, and Accountability (HSEA) Organization manages the groundwater monitoring activities in each regime under the auspices of the Y-12 Plant Groundwater Protection Program (GWPP). The purpose of the GWPP is to characterize the hydrogeology and to monitor groundwater quality at the Y-12 Plant and surrounding area to protect local groundwater resources in accordance with federal, state, and local regulations, DOE Orders, and Lockheed Martin Energy Systems, Inc. (Energy Systems) corporate policy. The annual GWQR for the Chestnut Ridge Regime is completed in two parts. Part 1 consists primarily of data appendices and serves as a reference for the groundwater quality data obtained each CY under the lead of the Y-12 Plant GWPP. Because it contains information needed to comply with reporting requirements of Resource Conservation and Recovery Act (RCRA) interim status assessment monitoring, the Part 1 GWQR is submitted to the Tennessee Department of Environment and Conservation (TDEC) by the RCRA reporting deadline (March 1 of the following CY); Energy Systems submitted the 1994 Part 1 GWQR for the Chestnut Ridge Regime to the TDEC in February 1995 (HSW Environmental Consultants, Inc. 1995a).

  3. Southern Juan De Fuca Ridge and Escanaba Trough, Gorda Ridge: Comparison of hydrothermal deposits in sediment-free and sediment-covered ridge settings

    SciTech Connect

    Benninger, L.M.; Randolph, M.; Koski, A.; Zierenberg, R.A. )

    1990-06-01

    Southern Juan De Fuca Ridge (SJDF) is a low-relief, sediment-starved ridge axis that has a total opening rate of 6 cm/year and is characterized by lobate and brecciated sheet flows and pillows of MORB composition. Sulfide deposits form at {approximately}2,200 m water depth and are concentrated within a narrow graben centered within the ridge axial valley. Solitary and coalesced chimneys (0.25 to 12 m high) rise directly from the basalt basement and are composed predominantly of Zn sulfide accompanied by Fe and Cu-Fe sulfide and traces of Pb sulfide. Anhydrite occurs as a minor phase in some chimneys. Sulfide chimneys were formed by rapid-venting of high temperature ({approximately}285{degree}C) fluids. These acidic fluids (pH {approximately}3.5) are enriched in Cl, Na, and Ca and are depleted in Cu and Zn. In contrast to SJDF, Escanaba Trough (ET) is spreading at {approximately}2.3 cm/year and has the high relief and axial graben morphology typical of the slow-spreading Mid-Atlantic Ridge. The floor of the axial valley is buried by up to 500 m of clay and terrigenous silt. Rare basement exposures reveal unbrecciated sheet flows and pillow basalts of MORB composition. Large chimney-topped sulfide mounds up to 20 m high and hundreds of meters in extent occur at {approximately}3,250 m water depth at the base of sediment hills; sulfide veins, small chimneys, and clastic deposits occur on, and within, the sediment between hills. Two distinct sulfide types occur at ET. Pyrrhotite-rich sulfide is enriched in Fe, Cu, and As and is associated with low-velocity venting of warm (<220{degree} C) alkaline (pH {approximately}5.4) fluids that are currently depositing anhydrite and barite sinter deposits on top of the sulfide mounds.

  4. Surface radiological investigations along State Highway 95, Lagoon Road, and Melton Valley Drive, Oak Ridge Reservation, Oak Ridge, Tennessee

    SciTech Connect

    Tiner, P.F.; Uziel, M.S.; Rice, D.E.; Williams, J.K.

    1995-08-01

    The surface radiological investigation along State Highway 95, Lagoon Road, and Melton Valley Drive at the Oak Ridge Reservation was conducted as part of the Oak Ridge National Laboratory Environmental Restoration Program Surveillance and Maintenance activities. This report was prepared to document results of the investigation and subsequent remedial actions. The report details surface gamma radiation levels including gamma anomalies; surface beta radiation levels including beta anomalies; results of analysis of soil, water, and vegetation samples and smear samples collected from paved surfaces; remediation activities conducted as a result of the survey; and recommendations for further corrective measures.

  5. Characterizing Microorganisms in Pillow Lava From the East Indian Ridge and From the Arctic Ridges

    NASA Astrophysics Data System (ADS)

    Lysnes, K.; Steinsbu, B. O.; Einen, J.; Torsvik, T.; Thorseth, I. H.; Pedersen, R. B.

    2001-12-01

    Microbial investigations has been carried out on basalts drilled from 10-30 Ma oceanic crust north of the Australian-Antarctic Discordance (ODP Leg 187) and dredged from the neovolcanic zones of the Mohns and Knipovich Ridges (Norwegian-Greenland Sea). The main objectives with the study are to document microbial diversity of the oceanic subsurface biosphere, and in particular to identify microorganisms participating in basalt alteration. Microorganisms in the pillow lava were characterized using enrichment techniques and DNA based methods. Cultivation experiments were started on board immediately after collecting the samples. Seawater and sediment samples were collected for comparison. The enrichment culture media were aimed at microorganisms participating in the iron, manganese, sulfur, and methane cycles. DNA, extracted directly from basalt, sediment and seawater, and from enrichment cultures, was used for PCR, DGGE and 16S rDNA sequencing. Results from enrichment studies, chemical analysis of metabolic products and DNA based techniques show that iron and manganese oxidizing and reducing bacteria, methanotrophic bacteria, and methanogenic Archaea are present in the basalt samples. These main functional groups of bacteria were found in both the 10-30 Ma drill samples and the neovolcanic dredge samples. The DNA based techniques reveal that the native basalt samples contain mostly uncultured and unidentified groups of microbes. Sulfate reducing bacteria were not abundant in the basalt samples, but were common in the seawater and sediment samples.

  6. Environmental monitoring plan for Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1995-09-01

    This document presents an Environmental Monitoring Plan (EMP) for Waste Area Grouping (WAG 6) at Oak Ridge National Laboratory (ORNL). This document updates a draft monitoring plan developed in 1993. The draft plan was never finalized awaiting resolution of the mechanisms for addressing RCRA concerns at a site where the CERCLA process resulted in a decision to defer action, i.e., postpone closure indefinitely. Over the past two years the Tennessee Department of Environment and Conservation (TDEC), US Department of Energy (DOE), and US Environmental Protection Agency (EPA) Region IV, have agreed that RCRA authority at the site will be maintained through a post- closure permit; ``closure`` in this case referring to deferred action. Both a Revised Closure Plan (DOE 1995a) and a Post-Closure Permit Application (DOE 1995b) have been developed to document this agreement; relevant portions of the EMP will be included in the RCRA Post-Closure Permit Application. As the RCRA issues were being negotiated, DOE initiated monitoring at WAG 6. The purpose of the monitoring activities was to (1) continue to comply with RCRA groundwater quality assessment requirements, (2) install new monitoring equipment, and (3) establish the baseline conditions at WAG 6 against which changes in contaminant releases could be measured. Baseline monitoring is scheduled to end September 30, 1995. Activities that have taken place over the past two years are summarized in this document.

  7. Environmental Monitoring Plan for Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1993-09-01

    This document presents the Environmental Monitoring Plan (EMP) for Waste Area Grouping (WAG) 6 at the Oak Ridge National Laboratory (ORNL). Based on the results of the Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) and on subsequent discussions with regulators, a decision was made to defer implementing source control remedial measures at the WAG. The alternative selected to address the risks associated with WAG 6 involves maintenance of site access controls prevent public exposure to on-site contaminants, continued monitoring of contaminant releases determine if source control measures are required, and development of technologies that could support the final remediation of WAG 6. Although active source control measures are not being implemented at WAG 6, environmental monitoring is necessary to ensure that any potential changes in contaminant release from the WAG are identified early enough to take appropriate action. Two types of environmental monitoring will be conducted: baseline monitoring and annual routine monitoring. The baseline monitoring will be conducted to establish the baseline contaminant release conditions at the WAG, confirm the site-related chemicals of concern (COCs), and gather data to confirm the site hydrologic model. The baseline monitoring is expected to begin in 1994 and last for 12--18 months. The annual routine monitoring will consist of continued sampling and analyses of COCs to determine off-WAG contaminant flux and risk, identify mills in releases, and confirm the primary contributors to risk. The annual routine monitoring will continue for {approximately} 4 years after completion of the baseline monitoring.

  8. Surface debris inventory at White Wing Scrap Yard, Oak Ridge Reservation, Oak Ridge, Tennessee

    SciTech Connect

    Rodriguez, R.E.; Tiner, P.F.; Williams, J.K.

    1992-08-01

    An inventory of surface debris in designated grid blocks at the White Wing Scrap Yard [Waste Area Grouping 11 (WAG 11)] was conducted intermittently from February through June 1992 by members of the Measurement Applications and Development Group, Health and Safety Research Division, Oak Ridge National Laboratory (ORNL) at the request of ORNL Environmental Restoration (ER) Program personnel. The objectives of this project are outlined in the following four phases: (1) estimate the amount (volume) and type (e.g., glass, metal and plastics) of surface waste material in 30 designated grid blocks (100- by 100-ft grids); (2) conduct limited air sampling for organic chemical pollutants at selected locations (e.g., near drums, in holes, or other potentially contaminated areas); (3) conduct a walkover gamma radiation scan extending outward (approximately 50 ft) beyond the proposed location of the WAG 11 perimeter fence; and (4) recommend one grid block as a waste staging area. This recommendation is based on location and accessibility for debris staging/transport activities and on low levels of gamma radiation in the grid block.

  9. Environmental Survey preliminary report, Oak Ridge Gaseous Diffusion Plant, Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1989-02-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the US Department of Energy's (DOE) Oak Ridge Gaseous Diffusion Plant (ORGDP) conducted March 14 through 25, 1988. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team components are being supplied by a private contractor. The objective of the Survey is to identify environmental risk associated with ORGDP. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at ORGDP, and interviews with site personnel. The Survey team developed a Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during is on-site activities. The Sampling and Analysis Plan will be executed by Idaho National Engineering Laboratory (INEL). When completed, the results will be incorporated into the ORGDP Survey findings for in inclusion into the Environmental Survey Summary Report. 120 refs., 41 figs., 74 tabs.

  10. 3001 canal radiological characterization and waste removal report, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Ritchie, M.G.

    1996-12-01

    An underground steel reinforced concrete transfer and storage canal was built in 1943 and operated as an integral part of the Oak Ridge Graphite Reactor Building (3001) until 1963 when the reactor was shutdown. During operation, the canal was used for under water transfer of irradiated materials and other metals from the reactor in Building 3001 to the Building 3019 hot cell for further processing. After shutdown of the reactor, the canal was used for storage of irradiated materials and fission products until 1990 when the larger materials were removed and stored in the Department of Energy (DOE) approved solid waste management storage facilities. At that time it was discovered that a considerable amount of sludge had accumulated over the intervening years and subsequent analysis showed that the sludge contained Resource Conservation and Recovery Act (RCRA) materials that violated quantities allowed by the RCRA regulations. It was also recognized in 1990 that the canal was losing water to evaporation and the ground at the rate of approximately 400 gallons per day. To maintain water quality; i.e., radionuclide content at or near DOE derived concentration guidelines (DCG), the water in the canal is constantly demineralized using a demineralizer in the Building 3001 and demineralized make up water is supplied from the Building 3004 demineralizer. This report summarizes the 301 Canal Cleanup Task and the solid waste removed from the 3001 Canal in 1996.

  11. Removal site evaluation report for the Isotope Facilities at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1996-07-01

    This removal site evaluation (RmSE) report of the Isotope Facilities at Oak Ridge National Laboratory (ORNL) was prepared to provide the Environmental Restoration Program with information necessary to evaluate whether hazardous and/or radiological contaminants in and around the Isotopes Facility pose a substantial risk to human health or the environment and if remedial site evaluations (RSEs) or removal actions are required. The scope of the project included: (1) a review of historical evidence regarding operations and use of the facility; (2) interviews with facility personnel concerning current and past operating practices; (3) a site inspection; and (4) identification of hazard areas requiring maintenance, removal, or remedial actions. The results of RmSE indicate that no substantial risks exist from contaminants present in the Isotope Facilities because adequate controls and practices exist to protect human health and the environment. The recommended correction from the RmSE are being conducted as maintenance actions; accordingly, this RmSE is considered complete and terminated.

  12. Environmental Survey preliminary report, Oak Ridge National Laboratory (X-10), Oak Ridge, Tennessee

    SciTech Connect

    Not Available

    1988-07-01

    This report presents the preliminary findings from the first phase of the Environmental Survey of the US Department of Energy (DOE) Oak Ridge National Laboratory (ORNL), X-10 site, conducted August 17 through September 4, 1987. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team specialists are outside experts supplied by a private contractor. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with ORNL. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. The on-site phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at ORNL, and interviews with site personnel. The Survey team developed a Sampling and Analysis Plan to assist in further assessing certain of the environmental problems identified during its on-site activities. The Sampling and Analysis Plan will be executed by a DOE National Laboratory or a support contractor. When completed, the results will be incorporated into the Environmental Survey Interim Report for ORNL. The Interim Report will reflect the final determinations of the ORNL Survey. 120 refs., 68 figs., 71 tabs.

  13. Screening of contaminants in Waste Area Grouping 2 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Blaylock, B.G.; Frank, M.L.; Hoffman, F.O.; Hook, L.A.; Suter, G.W.; Watts, J.A.

    1992-07-01

    Waste Area Grouping 2 (WAG 2) of the Oak Ridge National Laboratory (ORNL) is located in the White Oak Creek Watershed and is composed of White Oak Creek Embayment, White Oak Lake and associated floodplain, and portions of White Oak Creek (WOC) and Melton Branch downstream of ORNL facilities. Contaminants leaving other ORNL WAGs in the WOC watershed pass through WAG 2 before entering the Clinch River. Health and ecological risk screening analyses were conducted on contaminants in WAG 2 to determine which contaminants were of concern and would require immediate consideration for remedial action and which contaminants could be assigned a low priority or further study. For screening purposes, WAG 2 was divided into four geographic reaches: Reach 1, a portion of WOC; Reach 2, Melton Branch; Reach 3, White Oak Lake and the floodplain area to the weirs on WOC and Melton Branch; and Reach 4, the White Oak Creek Embayment, for which an independent screening analysis has been completed. Screening analyses were conducted using data bases compiled from existing data on carcinogenic and noncarcinogenic contaminants, which included organics, inorganics, and radionuclides. Contaminants for which at least one ample had a concentration above the level of detection were placed in a detectable contaminants data base. Those contaminants for which all samples were below the level of detection were placed in a nondetectable contaminants data base.

  14. Underground storage tank management plan, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee

    SciTech Connect

    1997-09-01

    The Underground Storage Tank (UST) Program at the Oak Ridge Y-12 Plant was established to locate UST systems at the facility and to ensure that all operating UST systems are free of leaks. UST systems have been removed or upgraded in accordance with Tennessee Department of Environment and Conservation (TDEC) regulations and guidance. With the closure of a significant portion of the USTs, the continuing mission of the UST Management Program is to manage the remaining active UST systems and continue corrective actions in a safe regulatory compliant manner. This Program outlines the compliance issues that must be addressed, reviews the current UST inventory and compliance approach, and presents the status and planned activities associated with each UST system. The UST Program provides guidance for implementing TDEC regulations and guidelines for petroleum UST systems. The plan is divided into three major sections: (1) regulatory requirements, (2) active UST sites, and (3) out-of-service UST sites. These sections describe in detail the applicable regulatory drivers, the UST sites addressed under the Program, and the procedures and guidance for compliance.

  15. Evaluation and monitoring plan for consolidation tanks: Gunite and Associated Tanks Operable Unit, Waste Area Grouping 1, Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1997-02-01

    This report describes the results of an integrity evaluation of Tanks W-8 and W-9, part of the Gunite and Associated Tanks (GAAT), in the South Tank Farm at Oak Ridge National Laboratory (ORNL), together with a plan for monitoring those tanks for potential releases during the GAAT CERCLA treatability study and waste removal activities. This work was done in support of an ORNL plan to use W-8 and W-9 as consolidation tanks during remediation of the other tanks in the North and South Tank Farms. The analysis portion of the report draws upon both tank-internal measurements of liquid volume change and tank-external measurements of the change in electrical conductivity of the groundwater in the dry wells adjacent to each tank. The results of the analysis show that both W-8 and W-9 are liquid-tight and are suitable for use as consolidation tanks. The recommended monitoring plan will utilize the dry well conductivity monitoring method as the primary release detection tool during the CERCLA activities. This method is expected to be able to detect releases of less than 0.5 gal/h with a 95% probability of detection, most of the time. The results described here validate three prior independent efforts: a liquid integrity assessment made in 1995, a structural integrity assessment made in 1995 by experts in the field of gunite tanks, and a structural integrity assessment made in 1994 using a three-dimensional, finite-element computer model. This work, along with the three prior efforts, shows that Tanks W-8 and W-9 are structurally sound and liquid-tight. Based upon this work it is concluded that these tanks are suitable for use as consolidation tanks during the GAAT CERCLA treatability study and waste removal actions and it is recommended that the tanks be monitored for potential releases during this period using the methods described in this report.

  16. Bayesian Factor Analysis as a Variable-Selection Problem: Alternative Priors and Consequences.

    PubMed

    Lu, Zhao-Hua; Chow, Sy-Miin; Loken, Eric

    2016-01-01

    Factor analysis is a popular statistical technique for multivariate data analysis. Developments in the structural equation modeling framework have enabled the use of hybrid confirmatory/exploratory approaches in which factor-loading structures can be explored relatively flexibly within a confirmatory factor analysis (CFA) framework. Recently, Muthén & Asparouhov proposed a Bayesian structural equation modeling (BSEM) approach to explore the presence of cross loadings in CFA models. We show that the issue of determining factor-loading patterns may be formulated as a Bayesian variable selection problem in which Muthén and Asparouhov's approach can be regarded as a BSEM approach with ridge regression prior (BSEM-RP). We propose another Bayesian approach, denoted herein as the Bayesian structural equation modeling with spike-and-slab prior (BSEM-SSP), which serves as a one-stage alternative to the BSEM-RP. We review the theoretical advantages and disadvantages of both approaches and compare their empirical performance relative to two modification indices-based approaches and exploratory factor analysis with target rotation. A teacher stress scale data set is used to demonstrate our approach.

  17. The Blue Ridge Dinner Theatre: A Recipe for Success.

    ERIC Educational Resources Information Center

    McCaslin, Nellie

    2002-01-01

    Describes an example of intergenerational theatre--the annual production at the Blue Ridge Dinner Theatre, Ferrum College, Virginia. Notes that in addition to four plays for adults, one play is for family audiences and includes area children. Suggests the program offers patrons quality entertainment, gives unique experience to area children, and…

  18. 9. VIEW FROM MANY PARKS CURVE (ON TRAIL RIDGE ROAD) ...

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

    9. VIEW FROM MANY PARKS CURVE (ON TRAIL RIDGE ROAD) OF HORSESHOE PARK, SHOWING FALL RIVER ROAD FAINTLY AT LEFT AT BASE OF SHEEP MOUNTAIN AND CROSSING ALLUVIAL FAN FROM LAWN LAKE FLOOD. - Fall River Road, Between Estes Park & Fall River Pass, Estes Park, Larimer County, CO

  19. Link between ridge subduction and gold mineralization in southern Alaska

    USGS Publications Warehouse

    Haeussler, Peter J.; Bradley, Dwight C.; Goldfarb, Richard; Snee, Lawrence W.; Taylor, Cliff D.

    1995-01-01

    40Ar/39Ar geochronology reveals that turbidite-hosted gold deposits in the southern Alaska accretionary prism are the same age as nearby near-trench plutons. These early Tertiary plutons and gold lodes formed above a slab window during subduction of an oceanic spreading center. Ridge subduction is a previously unrecognized tectonic process for the generation of lode gold.

  20. Remanent magnetization model for the broken ridge satellite magnetic anomaly

    NASA Technical Reports Server (NTRS)

    Johnson, B. D.

    1983-01-01

    A crustal model for the interpretation of the Broken Ridge satellite magnetic anomaly was constructed from bathymetric data assuming an Airy-type isostatic compensation. An average crustal magnetization of 6 A.m is required to account for the observed anomaly amplitudes provided that the whole crust is homogeneously magnetized. In contrast, a model representing only the topographic expression of the Broken Ridge, above the surrounding sea floor, requires a magnetization of the order of 40 A.m-1. Since this latter figure is much higher than is to be expected from studies of magnetic properties of oceanic rocks, it is concluded that the majority of the crustal volume of Broken Ridge is magnetized relatively uniformly. The direction of the source magnetization is consistent with an inclination shallower than the present geomagnetic field and close to that of an axial dipole. Since a more northerly source location for Broken Ridge is contrary to the paleolatitude data it is though that the magnetization represents a magnetization obtained by averaging the geomagnetic field direction over a sufficient time to remove secular variation effects. This pattern is indicative of viscous magnetization.

  1. Technology Solutions Case Study: Foundation Heat Exchanger, Oak Ridge, Tennessee

    SciTech Connect

    2014-03-01

    The foundation heat exchanger, developed by Oak Ridge National Laboratory, is a new concept for a cost-effective horizontal ground heat exchanger that can be connected to water-to-water or water-to-air heat pump systems for space conditioning as well as domestic water heating.

  2. 6. INTERIOR VIEW OF MAIN ROOM SHOWING DAMAGE AT RIDGE ...

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

    6. INTERIOR VIEW OF MAIN ROOM SHOWING DAMAGE AT RIDGE CAUSED BY SOLID ROCKET FUEL BURNING ON AND THROUGH THE ROOF; VIEW TO WEST. - Cape Canaveral Air Station, Launch Complex 17, Facility 36009, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL

  3. Oak Ridge National Laboratory Institutional Plan, FY 1995--FY 2000

    SciTech Connect

    Not Available

    1994-11-01

    This report discusses the institutional plan for Oak Ridge National Laboratory for the next five years (1995-2000). Included in this report are the: laboratory director`s statement; laboratory mission, vision, and core competencies; laboratory plan; major laboratory initiatives; scientific and technical programs; critical success factors; summaries of other plans; and resource projections.

  4. Oak Ridge Reservation Annual Site environmental report for 1994

    SciTech Connect

    Koncinski, W.S.

    1995-10-01

    This report presents the details of the environmental monitoring and management plan for the Oak Ridge Reservation. Topics include: site and operations overview; environmental compliance strategies; environmental management program; effluent monitoring; environmental surveillance; radiation doses; chemical doses; ground water; and quality assurance.

  5. Thermal resistance of ridge-waveguide lasers mounted upside down

    SciTech Connect

    Amann, M.

    1987-01-05

    The heat dissipation in upside down mounted ridge-waveguide lasers equipped with a double-channel structure is analyzed by a simplified device model. Assuming an isothermal active region, the thermal resistance is obtained by means of conformal mapping. A comparison to published experimental results shows good agreement.

  6. 14. VIEW FROM TUNDRA CURVES (ON TRAIL RIDGE ROAD) SHOWING ...

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

    14. VIEW FROM TUNDRA CURVES (ON TRAIL RIDGE ROAD) SHOWING FALL RIVER ROAD RISING FROM BENEATH CHAPIN PASS (AT EXTREME RIGHT) TO FALL RIVER PASS (FAR LEFT). - Fall River Road, Between Estes Park & Fall River Pass, Estes Park, Larimer County, CO

  7. Photolithography fabrication of sol-gel ridge waveguides

    NASA Astrophysics Data System (ADS)

    Sara, Rahmani; Touam, Tahar; Blanchetiere, Chantal; Saddiki, Z.; Saravanamuttu, Kalaichelvi; Du, Xin M.; Chrostowski, Jacek; Andrews, Mark P.; Najafi, S. Iraj

    1998-07-01

    We report on fabrication of ridge waveguides in UV-light sensitive glass sol-gel thin films, deposited on silicon substrate, using a simple photolithography process. The single-layer films are prepared at low temperature and deep UV-light (DUV) is employed to make the waveguides. The effect of fabrication parameters on waveguide shape is investigated.

  8. Oak Ridge Reservation, annual site environmental report for 1993

    SciTech Connect

    Not Available

    1994-11-01

    The US DOE currently oversees activities on the Oak Ridge Reservation, a government-owned, contractor-operated facility. Three sites compose the reservation; Y-12, Oak Ridge National Laboratory, and K-25. This document contains a summary of environmental monitoring activities on the Oak Ridge Reservation (ORR) and its surroundings. The results summarized in this report are based on the data collected during calendar year (CY) 1993 and compiled in; Environmental Monitoring in the Oak Ridge Reservation: CY 1993 Results. Annual environmental monitoring on the ORR consists of two major activities: effluent monitoring and environmental surveillance. Effluent monitoring is the collection and analysis of samples or measurements of liquid, gaseous, or airborne effluents for the purpose of characterizing and quantifying contaminants and process stream characteristics, assessing radiation and chemical exposures to members of the public, and demonstrating compliance with applicable standards. Environmental surveillance is the collection and analysis of samples of air, water, soil, foodstuffs, biota, and other media from DOE sites and their environs and the measurement of external radiation for purposes of demonstrating compliance with applicable standards, assessing radiation and chemical exposures to members of the public, and assessing effects, if any, on the local environment.

  9. Detail of the ridge framing of the clerestory roof, note ...

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

    Detail of the ridge framing of the clerestory roof, note the alternating wood and steel beams, view facing northeast - U.S. Marine Corps Base Hawaii, Kaneohe Bay, Warehouse 250, Aviation Storehouse, C Street between Fifth & Sixth Streets, Kaneohe, Honolulu County, HI

  10. Curvilinear ridges and related features in southwest Cydonia Mensae, Mars

    NASA Technical Reports Server (NTRS)

    Parker, Timothy J.; Schneeberger, Dale M.; Pieri, David C.; Saunders, R. Stephen

    1987-01-01

    Examined is a region on Mars in southwest Cydonia Mensae (32 deg lat., 17 deg long.) just northwest of the lowland/upland boundary escarpment. The dominant morphological features in this region are the clusters of large massifs and plateau outliers (PI), knobby material (K), and smooth lowland plains (Ps). Surrounding the clusters and linking many isolated knobs is a system of curvilinear ridges and arcuate terrain boundaries which tend to separate the massifs and knobs from the smooth plains. Curvilinear ridges are arcuate to nearly linear and smoother in plan than wrinkle ridges and show no apparent correlation with regional structural grain. They are typically 5 to 10 km long but can range from as little as 2 or 3 km to greater than 50 km long. The widths vary from about 100 m to as much as 2 km. Curvilinear ridges are most numerous within 100 km of the lowland/upland boundary escarpment and are associated with massifs and knobby terrain. Arcuate terrain boundaries appear between units of different apparent albedo or arcuate breaks in slope.

  11. Environmental Compliance and Protection Program Description Oak Ridge, Tennessee

    SciTech Connect

    Bechtel Jacobs

    2009-02-26

    The objective of the Environmental Compliance and Protection (EC and P) Program Description (PD) is to establish minimum environmental compliance requirements and natural resources protection goals for the Bechtel Jacobs Company LLC (BJC) Oak Ridge Environmental Management Cleanup Contract (EMCC) Contract Number DE-AC05-98OR22700-M198. This PD establishes the work practices necessary to ensure protection of the environment during the performance of EMCC work activities on the US Department of Energy's (DOE's) Oak Ridge Reservation (ORR) in Oak Ridge, Tennessee, by BJC employees and subcontractor personnel. Both BJC and subcontractor personnel are required to implement this PD. A majority of the decontamination and demolition (D and D) activities and media (e.g., soil and groundwater) remediation response actions at DOE sites on the ORR are conducted under the authority of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). CERCLA activities are governed by individual CERCLA decision documents (e.g., Record of Decision [ROD] or Action Memorandum) and according to requirements stated in the Federal Facility Agreement for the Oak Ridge Reservation (DOE 1992). Applicable or relevant and appropriate requirements (ARARs) for the selected remedy are the requirements for environmental remediation responses (e.g., removal actions and remedial actions) conducted under CERCLA.

  12. Oak Ridge Reservation. Physical Characteristics and National Resources

    SciTech Connect

    Parr, Patricia Dreyer; Joan, F. Hughes

    2006-10-09

    The topology, geology, hydrology, vegetation, and wildlife of the Oak Ridge Reservation (ORR) provide a complex and intricate array of resources that directly impact land stewardship and use decisions. The purpose of this document is to consolidate general information regarding the natural resources and physical characteristics of the ORR.

  13. Geometrical constraints on the evolution of ridged sea ice

    NASA Astrophysics Data System (ADS)

    Amundrud, Trisha L.; Melling, Humfrey; Ingram, R. Grant

    2004-06-01

    A numerical model of the evolving draft distribution of seasonal pack ice is driven by freezing and ice field compression in one dimension. Spatial transects of sea ice draft acquired during winter in the Beaufort Sea are used to evaluate the model. Histograms obtained by ice-profiling sonar on subsea moorings reveal changes in the draft distribution, while observations of ice velocity by Doppler sonar allow calculation of the strain to which the draft distribution is responding. Numerical diffusion in thermal ice growth is controlled using a remapping algorithm. Mechanical redistribution algorithms in common use generate much more deep ridged ice than is observed. Geometric constraints on ridge-keel development that reflect the finite extent of level floes available for ridge building and the true average shape of keels produce more realistic results. In the seasonal pack ice of the Beaufort Sea, 75% of all floes are too small to provide a volume of ice sufficient to construct a keel of draft equal to that commonly assumed in ice dynamics modeling. On average, the distribution of draft within keels has a negative exponential form, implying a cusped keel shape with more area on the thinner flanks than at the crest; models commonly assume a uniform redistribution of ice into a keel of triangular shape. Clearly, the spatial organization of ice within seasonal pack or, equivalently, the existence of ridges and floes should be an acknowledged factor in redistribution theory for pack ice thickness.

  14. Stellar contributions to the hard X-ray galactic ridge

    NASA Technical Reports Server (NTRS)

    Worrall, S. M.; Marshall, F. E.

    1982-01-01

    The number density of serendipitous sources in galactic plane Einstein Observatory IPC fields are compared with predictions based on the intensity of the HEAO-1 A2 unresolved hrd X-ray galactic ridge emission. It is concluded that theoretically predicted X-ray source populations of luminosity 8 x 10 to the 32nd power to 3 x 10 to the 34th power ergs s have 2 KeV to 10 KeV local surface densities of less than approximately .0008 L(32) pc/2 and are unlikely to be the dominant contributors to the hard X-ray ridge. An estimate for Be/neutron star binary systems, such as X Persei, gives a 2 keV to 10 keV local surface density of approximately 26 x 10 to the -5 power L(32) pc/2. Stellar systems of low luminosity, are more likely contributors. Both RS CVn and cataclysmic variable systems contribute 43% + or - 18% of the ridge. A more sensitive measurement of the ridge's hard X-ray spectrum should reveal Fe-line emission. We speculate that dM stars are further major contributors.

  15. Oak Ridge Research reactor shutdown maintenance and surveillance

    SciTech Connect

    Coleman, G.H.; Laughlin, D.L.

    1991-05-01

    The Department of Energy ordered the Oak Ridge Research Reactor to be placed in permanent shutdown on July 14, 1987. The paper outlines routine maintenance activities and surveillance tests performed April through September, 1990, on the reactor instrumentation and controls, process system, and the gaseous waste filter system. Preparations are being made to transfer the facility to the Remedial Action Program. 6 tabs. (MHB)

  16. 78 FR 69447 - Agency Information Collection Activities; Existing Collection, Comments Requested: Friction Ridge...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-19

    ... Requested: Friction Ridge Cards: Arrest and Institution; Applicant; Personal Identification; FBI Standard... Reinstatement. The Department of Justice (DOJ), Federal Bureau of Investigation (FBI), Criminal Justice... form/collection: Friction Ridge Cards: Arrest and Institution; Applicant; Personal Identification;...

  17. 75 FR 73069 - Enstor Grama Ridge Storage and Transportation, LLC, Enstor Katy Storage and Transportation, LP...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-29

    ...; Docket No. PR10-83-001] Enstor Grama Ridge Storage and Transportation, LLC, Enstor Katy Storage and Transportation, LP, et al.; Notice of Baseline Filings November 18, 2010. Enstor Grama Ridge Storage Docket...

  18. Results of the measurement survey of elevation and environmental media in surface impoundments 3513 (B) and 3524 (A) at Oak Ridge National Laboratory, Oak Ridge, TN

    SciTech Connect

    Murray, M.E.; Rose, D.A.; Brown, K.S.; Coe, R.H.C. III; Lawrence, J.D.; Winton, W.

    1998-07-01

    A measurement survey of the elevation and environmental media in impoundments 3513 (B) and 3524 (A) at the Oak Ridge National Laboratory (ORNL) was conducted during April 1998. The investigation was performed by the Measurement Applications and Development Group of the Life Sciences Division of ORNL at the request of Bechtel Jacobs Company. Measurement activities were conducted at selected locations in order to determine the depth and appearance of the sediment and describe the clay underlying the impoundments prior to remediation. The survey was a follow-up to a previous elevation survey. The survey included the following: collection of sediment/clay cores from selected locations in each impoundment; measurement and documentation of the elevation at the water surface, at the top of sediment, at the top of clay, and at the bottom of each core; visual inspection of each core by a soil scientist to confirm the presence of clay and not material such as fly ash and soda lime compacted over the last 50 years; measurement and documentation of the background beta-gamma radiation level at the time and location of collection of each core, the highest beta-gamma level along the sediment portion of each core, and the highest beta-gamma level along the clay portion of each core; measurement and documentation of the length of the clay and of the sediment portion of each core; photographic documentation of each core; and replacement of each core in the impoundment.

  19. Pitch perception prior to cortical maturation

    NASA Astrophysics Data System (ADS)

    Lau, Bonnie K.

    Pitch perception plays an important role in many complex auditory tasks including speech perception, music perception, and sound source segregation. Because of the protracted and extensive development of the human auditory cortex, pitch perception might be expected to mature, at least over the first few months of life. This dissertation investigates complex pitch perception in 3-month-olds, 7-month-olds and adults -- time points when the organization of the auditory pathway is distinctly different. Using an observer-based psychophysical procedure, a series of four studies were conducted to determine whether infants (1) discriminate the pitch of harmonic complex tones, (2) discriminate the pitch of unresolved harmonics, (3) discriminate the pitch of missing fundamental melodies, and (4) have comparable sensitivity to pitch and spectral changes as adult listeners. The stimuli used in these studies were harmonic complex tones, with energy missing at the fundamental frequency. Infants at both three and seven months of age discriminated the pitch of missing fundamental complexes composed of resolved and unresolved harmonics as well as missing fundamental melodies, demonstrating perception of complex pitch by three months of age. More surprisingly, infants in both age groups had lower pitch and spectral discrimination thresholds than adult listeners. Furthermore, no differences in performance on any of the tasks presented were observed between infants at three and seven months of age. These results suggest that subcortical processing is not only sufficient to support pitch perception prior to cortical maturation, but provides adult-like sensitivity to pitch by three months.

  20. Putting Priors in Mixture Density Mercer Kernels

    NASA Technical Reports Server (NTRS)

    Srivastava, Ashok N.; Schumann, Johann; Fischer, Bernd

    2004-01-01

    This paper presents a new methodology for automatic knowledge driven data mining based on the theory of Mercer Kernels, which are highly nonlinear symmetric positive definite mappings from the original image space to a very high, possibly infinite dimensional feature space. We describe a new method called Mixture Density Mercer Kernels to learn kernel function directly from data, rather than using predefined kernels. These data adaptive kernels can en- code prior knowledge in the kernel using a Bayesian formulation, thus allowing for physical information to be encoded in the model. We compare the results with existing algorithms on data from the Sloan Digital Sky Survey (SDSS). The code for these experiments has been generated with the AUTOBAYES tool, which automatically generates efficient and documented C/C++ code from abstract statistical model specifications. The core of the system is a schema library which contains template for learning and knowledge discovery algorithms like different versions of EM, or numeric optimization methods like conjugate gradient methods. The template instantiation is supported by symbolic- algebraic computations, which allows AUTOBAYES to find closed-form solutions and, where possible, to integrate them into the code. The results show that the Mixture Density Mercer-Kernel described here outperforms tree-based classification in distinguishing high-redshift galaxies from low- redshift galaxies by approximately 16% on test data, bagged trees by approximately 7%, and bagged trees built on a much larger sample of data by approximately 2%.

  1. Theoretical priors on modified growth parametrisations

    SciTech Connect

    Song, Yong-Seon; Hollenstein, Lukas; Caldera-Cabral, Gabriela; Koyama, Kazuya E-mail: Lukas.Hollenstein@unige.ch E-mail: Kazuya.Koyama@port.ac.uk

    2010-04-01

    Next generation surveys will observe the large-scale structure of the Universe with unprecedented accuracy. This will enable us to test the relationships between matter over-densities, the curvature perturbation and the Newtonian potential. Any large-distance modification of gravity or exotic nature of dark energy modifies these relationships as compared to those predicted in the standard smooth dark energy model based on General Relativity. In linear theory of structure growth such modifications are often parameterised by virtue of two functions of space and time that enter the relation of the curvature perturbation to, first, the matter over- density, and second, the Newtonian potential. We investigate the predictions for these functions in Brans-Dicke theory, clustering dark energy models and interacting dark energy models. We find that each theory has a distinct path in the parameter space of modified growth. Understanding these theoretical priors on the parameterisations of modified growth is essential to reveal the nature of cosmic acceleration with the help of upcoming observations of structure formation.

  2. Obstetrics in Mexico prior to 1600.

    PubMed

    Van Patten, N

    1932-03-01

    Surviving Indian codices and inscriptions, reports written down by the Spanish, and continuity of practice from pre-conquest times are the sources of knowledge about obstetrics in Mexico prior to 1600. Antenatal care included avoidance of exposure to heat, no sleep during the day, and plenty of nourishment, although certain dietary precautions were recommended. Moderate intercourse during the first trimester was permitted but prohibited near the time of parturition. In general, midwives counseled the prospective mother to eat well, to rest physically and mentally, and to engage very moderately in manual labor. Massage was given at regular intervals, and vapor baths were taken. Juices of medicinal plants were administered during labor both to expedite it and to relieve pain. Women assumed a squatting position during labor, which was also assisted by abdominal massage and the manual dilation of the vulva. If parturition was prolonged, pressure was applied by the midwife who used her feet for this purpose. The child was bathed immediately after birth. Lactation was prolonged among the Mexicans.

  3. Cathodic ARC surface cleaning prior to brazing

    SciTech Connect

    Dave, V. R.; Hollis, K. J.; Castro, R. G.; Smith, F. M.; Javernick, D. A.

    2002-01-01

    Surface cleanliness is one the critical process variables in vacuum furnace brazing operations. For a large number of metallic components, cleaning is usually accomplished either by water-based alkali cleaning, but may also involve acid etching or solvent cleaning / rinsing. Nickel plating may also be necessary to ensure proper wetting. All of these cleaning or plating technologies have associated waste disposal issues, and this article explores an alternative cleaning process that generates minimal waste. Cathodic arc, or reserve polarity, is well known for welding of materials with tenacious oxide layers such as aluminum alloys. In this work the reverse polarity effect is used to clean austenitic stainless steel substrates prior to brazing with Ag-28%Cu. This cleaning process is compared to acid pickling and is shown to produce similar wetting behavior as measured by dynamic contact angle experiments. Additionally, dynamic contact angle measurements with water drops are conducted to show that cathodic arc cleaning can remove organic contaminants as well. The process does have its limitations however, and alloys with high titanium and aluminum content such as nickel-based superalloys may still require plating to ensure adequate wetting.

  4. Are Axial Volcanic Ridges where all the (volcanic) action is?

    NASA Astrophysics Data System (ADS)

    Searle, R. C.

    2012-12-01

    Although axial volcanic ridges (AVRs) are generally recognised as the main loci for lithospheric generation at slow-spreading mid-ocean ridges, various recent studies have suggested that axial volcanism is not confined to them. Here I present evidence from three studies for significant amounts of off-AVR volcanism at three slow-spreading ridges. 1) Near-bottom side-scan sonar (TOBI) images of the Mid-Atlantic Ridge near 13°N show a complex pattern of closely-spaced, active oceanic core complexes (OCCs) where plate separation is largely a-volcanic, separated by short segments of vigorous volcanic spreading. In one such volcanic segment, the brightest sea floor and therefore inferred youngest volcanism occurs not on the topographic axis (an apparently 'old' AVR) but at the edge of a broad axial valley. 2) A similar TOBI survey of the Mid-Cayman Spreading Centre reveals AVRs in the north and south flanking an OCC (Mt. Dent) and a non-volcanic ridge interpreted as tectonically extruded peridotite ('smooth' sea floor). In both AVR segments there are clear, young lava flows that have erupted from perched sources part way up the median valley walls and have partly flowed down into the valley. 3) The third case is from the Mid-Atlantic Ridge at 45°N, where we conducted a detailed geophysical and geological study of an AVR and surrounding median valley floor. The AVR is largely surrounded by flat sea floor composed mainly of lobate and sheet flows, whereas the AVR comprises predominantly pillow lavas. Although we have no firm dates, various indicators suggest most lavas on the AVR are around 10ka old or somewhat less. The apparently youngest (brightest acoustic returns, thinnest sediment cover) of the flat-lying lava flows appears to have a similar age from its degree of sediment cover. Contact relations between these lavas and the AVR flanks show no evidence of a clear age difference between the two, and we think both types of eruption may have occurred roughly

  5. Abyssal Peridotites and Mantle Melting Beneath Ocean Ridges

    NASA Astrophysics Data System (ADS)

    Dick, H. J.; Snow, J. E.; Hellebrand, E.; Shimizu, N.

    2005-12-01

    Studies of abyssal peridotite from ultraslow and slow spreading ridges show significant regional variability; with a strong correlation between the compositions of peridotite averaged by locality and spatially associated MORB reflecting higher degrees of mantle melting near mantle hot spots. Local variability of peridotite compositions, however, is often large, and may equal the regional variability along ocean ridges. The latter is attributed to local melting and melt transport processes such as melt channelization or late-stage melt impregnation in the lithosphere. The observed regional correlation appears only when many samples are averaged to eliminate local and outcrop scale variability. Almost all the peridotites used in these correlations are from transforms, and therefore represent similar thermal and mantle melting histories. Thus, regional differences in mantle composition are preserved. Until recently, little data were available for peridotites away from transforms representing the central mantle environment beneath magmatic segments. This is key, as geophysical and geologic evidence suggest focused melt flow beneath slow spreading ridges. If so, beneath individual magmatic segments there should be a corresponding mantle melting cell in which melt is focused from a broad melting region to a melt transport zone at its mid-point that feeds an overlying crustal magmatic center. High melt fluxes in the transport zone would produce very depleted peridotites stripped of pyroxene by melt-rock reaction during magma ascent. Studies of peridotites far from transforms at ultraslow Gakkel and SW Indian Ridges indicate this is the case: with near-Cpx free intergranular harzburgite and dunite locally abundant in contrast to transform peridotites. Recent mapping of the plutonic foundation of an ancient 35-km long slow spreading ridge segment at the Kane Core Complex also found a narrow 10-km wide zone of focused melt flow through the mantle marked by abundant dunite

  6. The origin, classification and modelling of sand banks and ridges

    NASA Astrophysics Data System (ADS)

    Dyer, Keith R.; Huntley, David A.

    1999-08-01

    Sand banks and elongated sand ridges occur in many coastal and shelf seas where there is abundant sand and where the currents are strong enough to move sediment, but they have a wide variety of forms. Their generation requires a source of mobile sediment, either from the local sea bed, or from coast erosion. Most appear to have been created during the post-glacial rise in sea level, but they have been subsequently modified by changing currents and waves, thus losing their relict characteristics. A descriptive classification scheme is developed to unify the approaches of marine geologists and physical oceanographers, which emphasizes the formation and present hydrodynamic setting in their long-term development. Open shelf linear ridges (Type 1) are up to 80 km long, average 13 km wide and are tens of metres in height. They are oriented at an angle to the flow, are asymmetrical and appear to migrate in the direction of their steep face. They appear to be in near equilibrium with the flow. These contrast with linear ridges formed in mouths of wide estuaries, which are aligned with the flow, and which migrate away from their steeper face (Type2A). In narrow-mouthed estuaries and inlets, tidal currents are strong only close to the mouth and waves are more dominant. The banks then form close to the mouth as ebb and flood deltas (Type 2Bi). When the coast is retreating, the ebb delta forms a primary source of sand to the nearshore region, which can become modified by storm flows into `shore attached ridges' at angles to the coastline (Type 2Bii). Tidal eddies produced by headlands can create `banner banks' (Type 3A), but when the headland is retreating alternating or `en-echelon' ridges can be formed which can become isolated from the coast as it recedes (Type 3B). Coastal retreat and rising sea level can then cause the ridges to become moribund. Thus the majority of ridges rely on sea level rise for their origin. Theoretical and modelling studies of the shorter term

  7. Pressure Ridge Keel Shapes in the Chukchi and Beaufort Seas

    NASA Astrophysics Data System (ADS)

    Valenti, V. A.; Mahoney, A. R.; Metzger, A.; Eicken, H.

    2014-12-01

    Abstract: Recent aspirations for offshore development in the Chukchi and Beaufort seas, off the North Slope of Alaska, have precipitated the need of additional information for various sea-ice parameters. Of specific interest to engineers and regulatory agencies are the magnitudes of parameters representative of major hazards with a low expectation of occurring over some timeframe. The thickness and width of large pressure ridges that may impact offshore structures is of particular interest. Here, we analyze an extensive dataset from moored ice profiling sonars (IPSs) and acoustic Doppler current profilers (ADCPs) deployed in the vicinity of offshore oil-and-gas lease areas in the US portions of the Chukchi and Beaufort Seas. In all, we examine 16 annual time series of ice draft and velocity from six different mooring locations over five years. Using an automated algorithm, we identify individual pressure ridge keels based on deviations in ice draft from surrounding level ice and derive measurements of the maximum depth and shape of each. Of particular note, and contrary to many idealized ridges portrayed in the literature, we find that flat-bottomed keels are rare in this region. Since the orientation of each ridge as it passes over the mooring is unknown it is not possible to directly measure the precise width. Instead we bin the keels by maximum depth and find the modal width value for each depth bin. Finding that most keels have broadly the same triangular cross-section, we assume the modal width value corresponds to cases when the ridge passes over the mooring approximately perpendicular to its axis. Using this approach, we find a constant ratio between maximum keel depth and width, corresponding to a mean keel slope of around 33 degrees. This is somewhat steeper than is commonly found in literature. We also analyze the relationship between keel depth and drift speed, but find no statistically significant dependence.

  8. Diverse styles of volcanism at slow-spreading ridges (Invited)

    NASA Astrophysics Data System (ADS)

    Yeo, I. A.; Devey, C. W.; Searle, R. C.

    2013-12-01

    Slow-spreading mid-ocean ridge segments display an incredible diversity in morphology as a result of the volcanic processes occurring on them. The may have prominent axial highs or be floored by smooth, tectonised terrains. Where highs are present they may be smooth or hummocky, fill the valley or be surrounded by lower profile lava flows, and may exist not only in the centre, but also at the ends of segments. Individual eruptions may form one or more lava morphologies, be continuous or discontinuous and occur anywhere along the segment. This diversity is illustrated well in bathymetry and sidescan sonar from along the Mid-Atlantic Ridge. Multibeam bathymetry from sites along the MAR reveal large scale differences in morphology between segments, while higher resolution multibeam and sidescan datasets from AUVs alongside video and photographic information from ROVs help to elucidate the detailed volcanic morphologies associated with these larger scale differences. Hummocky terrain and smooth terrain are present in varying proportions on almost all slow-spreading segments, however may form in differing locations, or as parts of larger edifices. For example, smooth volcanic highs are morphologically and probably volcanologically different to hummocky axial volcanic ridges. In this contribution we compare and contrast bathymetric data from a number of different slow-spreading segments, including recently collected bathymetry from previously unsurveyed sections of the southern Mid-Atlantic Ridge, with high-resolution sidescan, multibeam and video observations to look at the variety of volcanic features on slow-spreading ridges and their impact for the construction of the upper oceanic crust.

  9. Anthropogenic disruption to the seismic driving of beach ridge formation: The Sendai coast, Japan.

    PubMed

    Goff, James; Knight, Jasper; Sugawara, Daisuke; Terry, James P

    2016-02-15

    The expected geomorphic after-effects of the Mw 9.0 Tōhoku-oki earthquake of 11 March 2011 (eastern Japan) are summarized by a schematic model of seismic driving, which details seismogenic disturbances to sediment systems that affect the rate or timing of sediment delivery to coastlines over timescales of 10(2)-10(4)years. The immediate physical environmental responses to this high-magnitude earthquake included a large tsunami and extensive region-wide slope failures. Normally, slope failures within mountain catchments would have significant impacts on Japan's river and coastal geomorphology in the coming decades with, for example, a new beach ridge expected to form within 20-100 years on the Sendai Plain. However, human activity has significantly modified the rate and timing of geomorphic processes of the region, which will have impacts on likely geomorphic responses to seismic driving. For example, the rivers draining into Sendai Bay have been dammed, providing sediment traps that will efficiently capture bedload and much suspended sediment in transit through the river system. Instead of the expected ~1 km of coastal progradation and formation of a ~3m high beach ridge prior to the next large tsunami, it is likely that progradation of the Sendai Plain will continue to slow or even cease as a result of damming of river systems and capture of river sediments behind dams. The resulting reduction of fluvial sediment delivery to the coast due to modification of rivers inadvertently makes seawalls and other engineered coastal structures even more necessary than they would be otherwise.

  10. 78 FR 3028 - Final Environmental Impact Statement for General Management Plan, Blue Ridge Parkway, Virginia...

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    ... National Park Service Final Environmental Impact Statement for General Management Plan, Blue Ridge Parkway... the General Management Plan (GMP) for Blue Ridge Parkway (parkway). Consistent with NPS laws... Ridge Parkway, 199 Hemphill Knob Road, Asheville, NC 28803. A limited number of compact disks...

  11. 75 FR 20859 - Temporary Concession Contract for Blue Ridge Parkway, NC/VA

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  1. 76 FR 1415 - Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation

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  16. 75 FR 51450 - Notice of 229 Boundary Revision for the Oak Ridge National Laboratory

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  17. 78 FR 63171 - Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation; Meeting

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    2010-06-22

    ... Environmental Management Site-Specific Advisory Board, Oak Ridge Reservation AGENCY: Department of Energy... Site-Specific Advisory Board (EM SSAB), Oak Ridge Reservation. The Federal Advisory Committee Act (Pub... Register. DATES: Wednesday, July 14, 2010, 6 p.m. ADDRESSES: DOE Information Center, 475 Oak Ridge...

  1. Seismic Structure of Malpelo and Cocos Volcanic Ridges and Implications for Hotspot - Mid-Oceanic Ridge Interaction

    NASA Astrophysics Data System (ADS)

    Sallares, V.; Charvis, P.; Flueh, E.; Walther, C.; Bialas, J.

    2001-12-01

    In this work we investigate the seismic structure of the Cocos and Malpelo Volcanic Ridges along three wide-angle profiles acquired during the PAGANINI-1999 experiment. The 2D velocity field and Moho geometry have been obtained using a joint refraction/reflection traveltime inversion method. Uncertainty and robustness of the results have been estimated by performing a Monte Carlo-type analysis. The results show that maximum crustal thickness along the three profiles range between 16 km (Southern Cocos) and 19 km (Northern Cocos and Malpelo). Oceanic Layer 2 thickness is quite uniform regardless of the crustal thickness variations, and thus crustal thickening is mainly accomodated in Layer 3. Seismic velocities of Layer 3 are similar in all profiles. We found several low velocity anomalies in the long-wavelength structure (up to ~6.8 km/s), which lead to an overall anticorrelation between crustal thickness and bulk lower crustal velocities. The Moho geometry of the Southern Cocos profile is highly asymmetric. The steep transition into a normal oceanic crust in the easternmost segment of this profile can be associated with the presence of the Inca Fracture Zone at the Cocos-Nazca Spreading Center. The rapid thinning of the northernmost segment of Malpelo Ridge can be most likely related with a rifting process that splitted the ancient Malpelo Ridge into Regina and Malpelo Ridges after the initiation of the movement along the Panam Fracture Zone.

  2. Site characterization plan for groundwater in Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Lee, R.R.; Curtis, A.H.; Houlberg, L.M.; Purucker, S.T.; Singer, M.L.; Tardiff, M.F.; Wolf, D.A.

    1994-07-01

    The Waste Area Grouping (WAG) 1 Groundwater Operable Unit (OU) at Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee, is undergoing a site characterization to identify environmental contamination that may be present. This document, Site Characterization Report for Groundwater in Waste Area Grouping I at Oak Ridge National Laboratory, Oak Ridge, Tennessee, identifies areas of concern with respect to WAG 1 groundwater and presents the rationale, justification, and objectives for conducting this continuing site characterization. This report summarizes the operations that have taken place at each of the areas of concern in WAG 1, summarizes previous characterization studies that have been performed, presents interpretations of previously collected data and information, identifies contaminants of concern, and presents an action plan for further site investigations and early actions that will lead to identification of contaminant sources, their major groundwater pathways, and reduced off-site migration of contaminated groundwater to surface water. Site characterization Activities performed to date at WAG I have indicated that groundwater contamination, principally radiological contamination, is widespread. An extensive network of underground pipelines and utilities have contributed to the dispersal of contaminants to an unknown extent. The general absence of radiological contamination in surface water at the perimeter of WAG 1 is attributed to the presence of pipelines and underground waste storage tank sumps and dry wells distributed throughout WAG 1 which remove more than about 40 million gal of contaminated groundwater per year.

  3. A new look at Northwind Ridge: implications for the history of the Canada Basin

    NASA Astrophysics Data System (ADS)

    Hutchinson, D. R.; Mosher, D. C.; Shimeld, J.; Jackson, R.; Chian, D.; Edwards, B. D.; Hart, P. E.; Mayer, L. A.

    2010-12-01

    ) models of the opening of CB may not require complete closure and therefore (2) NR may not overlap the continental margin of northern Canada, a problem with previous reconstructions. The northeast orientation of NR is subparallel to the inferred orientation of a deeply buried graben complex that is characterized by a northeast-trending negative gravity anomaly and offset ~250 km to the east of NR. Three northeast-trending bathymetric ridges also occur in the Sever Spur area or CB. Although the ages of rifting for either NR or the deeply buried graben complex are not well constrained, their subparallel orientation suggests this northeast direction is a preferred tectonic fabric either inherited prior to or created during the rifting and opening of the basin.

  4. Oblique convergence of the Kula plate: dextral transpression following ridge subduction, Chugach metamorphic complex, southern Alaska

    NASA Astrophysics Data System (ADS)

    Scharman, M.; Pavlis, T. L.

    2012-12-01

    The Chugach metamorphic complex (CMC), southern Alaska is a Mesozoic accretionary prism that has experienced high-temperature/low-pressure metamorphism due to subduction of the Kula-Farallon (or Kula-Resurrection) ridge in the Eocene. The Border Ranges fault acts as the northern boundary of the accretionary prism, and was active as a strike-slip system through many phases prior to, or during, CMC formation. Oblique plate subduction followed ridge subduction producing a dextral transpression system that is now exposed as a down-plunge view of a mid-crustal section. Dextral transpression and synchronous peak metamorphism produced a narrow gneiss core structurally overlain by amphibolite-facies meta-sedimentary rocks. Oblique subduction was preceded in the CMC by an initial convergence phase (D1) approximately orthogonal to the margin, and a second margin-parallel extension (D2) synchronous with the subducting ridge. D2 was diachronous with oblique subduction of the Kula plate (D3) which followed the trailing edge of the southward migrating triple junction. During D3, strain was partitioned with down-dip lineations and thrust-sense indicators along the southern CMC boundary, and multiple dextral strike-slip shear zones inboard from the former trench. These dextral shear zones produced wrench folding of the S2 foliation in the meta-sedimentary rocks and formation of the narrow gneiss core as a large-scale D3 anticlinorium. Great differences in wavelength of D3 folds between the gneiss core and the overlying meta-sedimentary rocks could indicate formation of a detachment zone during oblique convergence, or strike-slip shear zones that penetrate the gneiss core masked by similar wavelength folds. These D3 dextral shear zones inboard from the former trench suggest a distribution of dextral shear that accommodated the margin parallel motion component of Kula plate oblique subduction. Border Ranges fault dextral slip was effectively replaced during this brief Eocene period

  5. Scaling relations for galaxies prior to reionization

    SciTech Connect

    Chen, Pengfei; Norman, Michael L.; Xu, Hao; Wise, John H.; O'Shea, Brian W. E-mail: mlnorman@ucsd.edu E-mail: jwise@gatech.edu

    2014-11-10

    The first galaxies in the universe are the building blocks of all observed galaxies. We present scaling relations for galaxies forming at redshifts z ≥ 15 when reionization is just beginning. We utilize the 'Rarepeak' cosmological radiation hydrodynamics simulation that captures the complete star formation history in over 3300 galaxies, starting with massive Population III stars that form in dark matter halos as small as ∼10{sup 6} M {sub ☉}. We make various correlations between the bulk halo quantities, such as virial, gas, and stellar masses and metallicities and their respective accretion rates, quantifying a variety of properties of the first galaxies up to halo masses of 10{sup 9} M {sub ☉}. Galaxy formation is not solely relegated to atomic cooling halos with virial temperatures greater than 10{sup 4} K, where we find a dichotomy in galaxy properties between halos above and below this critical mass scale. Halos below the atomic cooling limit have a stellar mass-halo mass relationship log M {sub *} ≅ 3.5 + 1.3log (M {sub vir}/10{sup 7} M {sub ☉}). We find a non-monotonic relationship between metallicity and halo mass for the smallest galaxies. Their initial star formation events enrich the interstellar medium and subsequent star formation to a median of 10{sup –2} Z {sub ☉} and 10{sup –1.5} Z {sub ☉}, respectively, in halos of total mass 10{sup 7} M {sub ☉}, which is then diluted by metal-poor inflows well beyond Population III pre-enrichment levels of 10{sup –3.5} Z {sub ☉}. The scaling relations presented here can be employed in models of reionization, galaxy formation, and chemical evolution in order to consider these galaxies forming prior to reionization.

  6. Melt extraction and mantle source at a Southwest Indian Ridge Dragon Bone amagmatic segment on the Marion Rise

    NASA Astrophysics Data System (ADS)

    Gao, Changgui; Dick, Henry J. B.; Liu, Yang; Zhou, Huaiyang

    2016-03-01

    occurred at other place. Considering the hydrous melting of the initial Dragon Bone mantle source, we suggest the earlier melting event occurred in an arc terrain, prior to or during the closure of the Mozambique Ocean in the Neproterozoic, and the subsequent assembly of Gondwana. Then, the Al2O3 depleted and thus buoyant peridotites became the MORB source for Southwest Indian Ridge and formed the Marion Rise during the Gondwana breakup.

  7. Bayesian source separation with mixture of Gaussians prior for sources and Gaussian prior for mixture coefficients

    NASA Astrophysics Data System (ADS)

    Snoussi, Hichem; Mohammad-Djafari, Ali

    2001-05-01

    In this contribution, we present new algorithms to source separation for the case of noisy instantaneous linear mixture, within the Bayesian statistical framework. The source distribution prior is modeled by a mixture of Gaussians [1] and the mixing matrix elements distributions by a Gaussian [2]. We model the mixture of Gaussians hierarchically by mean of hidden variables representing the labels of the mixture. Then, we consider the joint a posteriori distribution of sources, mixing matrix elements, labels of the mixture and other parameters of the mixture with appropriate prior probability laws to eliminate degeneracy of the likelihood function of variance parameters and we propose two iterative algorithms to estimate jointly sources, mixing matrix and hyperparameters: Joint MAP (Maximum a posteriori) algorithm and penalized EM algorithm. The illustrative example is taken in [3] to compare with other algorithms proposed in literature. .

  8. Peritraumatic dissociation following motor vehicle accidents: relationship to prior trauma and prior major depression.

    PubMed

    Fullerton, C S; Ursano, R J; Epstein, R S; Crowley, B; Vance, K L; Kao, T C; Baum, A

    2000-05-01

    Individuals who dissociate at the time of a traumatic event (peritraumatic dissociation) are more likely to develop acute and chronic posttraumatic stress disorder (PTSD). However, little is known about who is at risk of peritraumatic dissociation. Motor vehicle accident subjects (N = 122) were systematically recruited and followed over 12 months. We used the Structured Clinical Interview for DSM-III-R (SCID) and the Peritraumatic Dissociative Experiences Questionnaire-Rater Version (PDEQ-RV). Younger subjects were more likely to experience peritraumatic dissociation as were white versus nonwhites, and single versus married subjects. Younger subjects reported a greater number of peritraumatic dissociative symptoms as did subjects with an injured passenger. After adjusting for age and passenger injury, prior major depression was significantly related to more peritraumatic dissociative symptoms. An interaction of age and prior major depression indicated that those who were younger and reported a history of major depression had the greatest number of peritraumatic dissociative symptoms.

  9. Elution of Nitrate at the NABIR Field Research Center, Oak Ridge Reservation, Oak Ridge, TN

    NASA Astrophysics Data System (ADS)

    Fienen, M. N.; Criddle, C. S.; Jardine, P. M.; Kitanidis, P. K.; Mehlhorn, T. L.; Watson, D. B.; Wu, W.

    2003-12-01

    As part of a bioremediation project for the in situ bioreduction of uranium at the Department of Energy Natural and Accelerated Bioremediation Research (NABIR) Field Research Center (FRC) in Oak Ridge, TN, aquifer and groundwater conditioning is required before conducting the remediation experiment. One step includes flushing of the aquifer with pH-adjusted fresh water in order to remove extremely high concentrations of nitrate, calcium, and aluminum that would interfere with in situ bioreduction. The elution of nitrate from the test zone was used as an inverse tracer to discern contaminant transport pathways and model parameters. Concentration time series data augmented pressure tests, a bromide tracer study, and electromagnetic borehole flowmeter (EBF) measurements. The aquifer at the FRC is a fractured shale with strike of about 1.5 degrees north of west, and dip of about 30 degrees to the southwest, as inferred from area observations and EBF logging. A network of injection and extraction wells are aligned along strike, while a separate network of observation wells with multiple screen intervals (MLS wells) are oriented along dip at the midpoint of the injection/extraction well network. Flow generally occurs along strike in fractures associated with bedding planes, however other lesser fracture networks provide communication between the major fracture sets. Previous data have indicated a high hydraulic conductivity zone, approximately 10-50 cm thick located at a depth of about 12 m along the centerline of the injection/extraction well network. Above the major flow zone, the matrix weathers to saprolite, decreasing hydraulic conductivity. The elution tracer test was conducted by injecting clean, acidified tap water in the farthest upgradient injection well, and extracting at half the injection rate from the farthest downgradient extraction well. This flow ratio was chosen to produce flushing focused on a small cell of the aquifer which will later be used as an in

  10. Planning and Execution of a Marine Methane Hydrate Pressure Coring Program for the Walker Ridge and Green Canyon Areas of the Gulf of Mexico

    SciTech Connect

    Humphrey, Gary

    2015-09-14

    The objective of this project (and report) is to produce a guide to developing scientific, operational, and logistical plans for a future methane hydrate-focused offshore pressure coring program. This report focuses primarily on a potential coring program in the Walker Ridge 313 and Green Canyon 955 blocks where previous investigations were undertaken as part of the 2009 Department of Energy JIP Leg II expedition, however, the approach to designing a pressure coring program that was utilized for this project may also serve as a useful model for planning pressure coring programs for hydrates in other areas. The initial portion of the report provides a brief overview of prior investigations related to gas hydrates in general and at the Walker Ridge 313 and Green Canyon 955 blocks in particular. The main content of the report provides guidance for various criteria that will come into play when designing a pressure coring program.

  11. Effects of CBRN decontaminants in common use by first responders on the recovery of latent fingerprints--assessment of the loss of ridge detail on glass.

    PubMed

    Zuidberg, Matthijs C; van Woerkom, Tiest; de Bruin, Karla G; Stoel, Reinoud D; de Puit, Marcel

    2014-01-01

    Following a CBRN incident, first responders use decontamination procedures to reduce the risk of exposure. The effect of decontamination on forensic trace material has, however, not been fully examined. This study sought to evaluate the effect of five different physical or chemical decontamination materials on the recovery of latent fingerprints. Fingerprints were deposited on glass slides, decontaminated, and assessed on the presence of ridge detail. The results demonstrate that decontamination affects the quality of latent fingerprints substantially. On at least 61% of the fingerprints, a reduced amount of ridge detail was observed upon decontamination. Furthermore, development with cyanoacrylate appeared not to succeed anymore. Instead, the ability of vacuum metal deposition to successfully develop decontaminated fingerprints is demonstrated. The results from this study may contribute to an increased forensic awareness regarding decontamination and emphasize the necessity for further research into new item decontamination procedures or new forensic initiatives prior to decontamination.

  12. Technology study of Gunite tank sludge mobilization at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    DeVore, J.R.; Herrick, T.J.; Lott, K.E.

    1994-12-01

    The Oak Ridge National Laboratory (ORNL) Gunite Tank Sludge Mobilization Technology Study was initiated to support the Gunite Tank Treatability Study effort. The technology study surveyed the methods and technologies available for tank cleaning and sludge mobilization in a radioactive environment. Technologies were identified and considered for applicability to the Gunite and Associated Tanks (GAAT) problems. These were then either accepted for further study or rejected as not applicable. Technologies deemed applicable to the GAAT sludge removal project were grouped for evaluation according to (1) deployment method, (2) types of remotely operated end effector equipment applicable to removal of sludge, (3) methods for removing wastes from the tanks, and (4) methods for concrete removal. There were three major groups of deployment technologies: ``past practice`` technologies, mechanical arm-based technologies, and vehicle-based technologies. The different technologies were then combined into logical sequences of deployment platform, problem, end effector, conveyance, post-removal treatment required (if any), and disposition of the waste. Many waste removal options are available, but the best technology in one set of circumstances at one site might not be the best type to use at a different site. No single technology is capable of treating the entire spectrum of wastes that will be encountered in GAAT. None of the systems used in other industries appears to be suitable, primarily because of the nature of the sludges in the GAAT Operable Unit (OU), their radiation levels, and tank geometries. Other commercial technologies were investigated but rejected because the authors did not believe them to be applicable.

  13. Robotic system for decommissioning the Gunite tanks at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Chesser, J.B.; Evans, J.H.; Norman, R.E.; Peishel, F.L.; Ruppel, F.R.

    1992-12-31

    Robotic systems and equipment to facilitate removal of the contents of the Oak Ridge National Laboratory (ORNL) Gunite Waste Tanks as well as the tanks themselves are one of several options being considered for this site. The technology described consists of proven remote systems and equipment or remote adaptations of proven industrial concepts. The proposed robotic system would be housed in a portable containment structure, fabricated from steel plate, and reinforced with structural shapes. The structure would be cylindrical and have a domed head. The containment structure would be sized to cover one tank. The tanks are in two sizes: 60 ft and 35 ft diameters. The structures would be supported on driven steel piles and would have an earthen berm around the base to enhance the effectiveness of the containment. Internal to the containment structure, a polar crane bridge equipped with a pair of trolley-mounted telescoping masts would be utilized to support and manipulate the systems, tools, etc., which would perform the individual tasks. The bridge and mast control system and the manipulator control system would provide both teleoperated and robotic modes to support either manual or preprogrammed operations. Equipment mounted at the end of the mast would include servomanipulators, water jet cutter, or a clam shell bucket. The mast would feature an interface plate allowing remote changeout of most mounted equipment. The operating system would be required to have the capability to decontaminate the dome and its equipment to the degree necessary to allow it to be relocated. Viewing would be provided by commercial closed-circuit TV (CCTV). It is believed that the systems described herein represent a feasible approach to removing the contents from the ORNL gunite tanks and implementing remediation of the site.

  14. Work plan for the Isotopes Facilities Deactivation Project at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    1995-08-01

    The purpose of the Isotopes Facilities Deactivation Project (IFDP) is to place former isotopes production facilities at the Oak Ridge National Laboratory in a safe, stable, and environmentally sound condition; suitable for an extended period of minimum surveillance and maintenance (S and M) and as quickly and economical as possible. Implementation and completion of the deactivation project will further reduce the risks to the environment and to public safety and health. Furthermore, completion of the project will result in significant S and M cost savings in future years. The IFDP work plan defines the project schedule, the cost estimate, and the technical approach for the project. A companion document, the EFDP management plan, has been prepared to document the project objectives, define organizational relationships and responsibilities, and outline the management control systems to be employed in the management of the project. The project has adopted the strategy of deactivating the simple facilities first, to reduce the scope of the project and to gain experience before addressing more difficult facilities. A decision support system is being developed to identify the activities that best promote the project mission and result in the largest cost savings. This work plan will be reviewed and revised annually. Deactivation of EFDP Facilities was initiated in FY 1994 and will be completed in FY 2000. The schedule for deactivation of facilities is shown. The total cost of the project is estimated to be $51M. The costs are summarized. Upon completion of deactivation, annual S and M costs of these facilities will be reduced from the current level of $5M per year to less than $1M per year.

  15. Level 3 baseline risk evaluation for Building 3506 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Golden, K.M.; Robers, S.K.; Cretella, F.M.

    1994-12-01

    This report presents the results of the Level 3 Baseline Risk Evaluation (BRE) performed on Building 3506 located at the Oak Ridge National Laboratory (ORNL). This BRE is intended to provide an analysis of the potential for adverse health effects (current or future) posed by contaminants at the facility. The decision was made to conduct a Level 3 (least rigorous) BRE because only residual contamination exists in the building. Future plans for the facility (demolition) also preclude a rigorous analysis. Site characterization activities for Building 3506 were conducted in fall of 1993. Concrete core samples were taken from the floors and walls of both the cell and the east gallery. These cores were analyzed for radionuclides and organic and inorganic chemicals. Smear samples and direct radiation measurements were also collected. Sediment exists on the floor of the cell and was also analyzed. To adequately characterize the risks posed by the facility, receptors for both current and potential future land uses were evaluated. For the current land use conditions, two receptors were evaluated. The first receptor is a hypothetical maintenance worker who spends 250 days (8 hours/day) for 25 years working in the facility. The remaining receptor evaluated is a hypothetical S and M worker who spends 2 days (8 hours/day) per year for 25 years working within the facility. This particular receptor best exemplifies the current worker scenario for the facility. The two current exposure scenarios and parameters of exposure (e.g., inhalation and ingestion rates) have been developed to provide a conservative (i.e. health protective) estimate of potential exposure.

  16. Robotic system for decommissioning the Gunite tanks at Oak Ridge National Laboratory, Oak Ridge, Tennessee

    SciTech Connect

    Chesser, J.B.; Evans, J.H.; Norman, R.E.; Peishel, F.L.; Ruppel, F.R.

    1992-01-01

    Robotic systems and equipment to facilitate removal of the contents of the Oak Ridge National Laboratory (ORNL) Gunite Waste Tanks as well as the tanks themselves are one of several options being considered for this site. The technology described consists of proven remote systems and equipment or remote adaptations of proven industrial concepts. The proposed robotic system would be housed in a portable containment structure, fabricated from steel plate, and reinforced with structural shapes. The structure would be cylindrical and have a domed head. The containment structure would be sized to cover one tank. The tanks are in two sizes: 60 ft and 35 ft diameters. The structures would be supported on driven steel piles and would have an earthen berm around the base to enhance the effectiveness of the containment. Internal to the containment structure, a polar crane bridge equipped with a pair of trolley-mounted telescoping masts would be utilized to support and manipulate the systems, tools, etc., which would perform the individual tasks. The bridge and mast control system and the manipulator control system would provide both teleoperated and robotic modes to support either manual or preprogrammed operations. Equipment mounted at the end of the mast would include servomanipulators, water jet cutter, or a clam shell bucket. The mast would feature an interface plate allowing remote changeout of most mounted equipment. The operating system would be required to have the capability to decontaminate the dome and its equipment to the degree necessary to allow it to be relocated. Viewing would be provided by commercial closed-circuit TV (CCTV). It is believed that the systems described herein represent a feasible approach to removing the contents from the ORNL gunite tanks and implementing remediation of the site.

  17. 37 CFR 2.36 - Identification of prior registrations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2010-07-01 2010-07-01 false Identification of prior registrations. 2.36 Section 2.36 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... prior registrations. Prior registrations of the same or similar marks owned by the applicant should...

  18. 37 CFR 2.36 - Identification of prior registrations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Identification of prior registrations. 2.36 Section 2.36 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... prior registrations. Prior registrations of the same or similar marks owned by the applicant should...

  19. 37 CFR 2.36 - Identification of prior registrations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2012-07-01 2012-07-01 false Identification of prior registrations. 2.36 Section 2.36 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE... prior registrations. Prior registrations of the same or similar marks owned by the applicant should...

  20. Recognition of Prior and Experiential Learning in European Universities

    ERIC Educational Resources Information Center

    Valk, Aune

    2009-01-01

    This paper focuses on the state of the art for recognition of prior experiential learning in European universities. Although recognition of prior learning and prior experiential learning have been officially stated as being important aims by national ministers of education in their Bologna Process communiques, implementation in the majority of…