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Sample records for adjacent tidal creek

  1. A long-term monitoring study of chlorophyll, microbial contaminants, and pesticides in a coastal residential stormwater pond and its adjacent tidal creek.

    PubMed

    DeLorenzo, Marie E; Thompson, Brian; Cooper, Emily; Moore, Janet; Fulton, Michael H

    2012-01-01

    Stormwater ponds are commonly used in residential and commercial areas to control flooding. The accumulation of urban contaminants in stormwater ponds can lead to water-quality problems including nutrient enrichment, chemical contamination, and bacterial contamination. This study presents 5 years of monitoring data assessing water quality of a residential subdivision pond and adjacent tidal creek in coastal South Carolina, USA. The stormwater pond is eutrophic, as described by elevated concentrations of chlorophyll and phosphorus, and experiences periodic cyanobacterial blooms. A maximum monthly average chlorophyll concentration of 318.75 μg/L was measured in the stormwater pond and 227.63 μg/L in the tidal creek. Fecal coliform bacteria (FCB) levels were measured in both the pond and the tidal creek that exceeded health and safety standards for safe recreational use. A maximum monthly average FCB level of 1,247 CFU/100 mL was measured in the stormwater pond and 12,850 CFU/100 mL in the tidal creek. In addition, the presence of antibiotic resistant bacteria and pathogenic bacteria were detected. Low concentrations of herbicides (atrazine and 2,4-D: ), a fungicide (chlorothalonil), and insecticides (pyrethroids and imidacloprid) were measured. Seasonal trends were identified, with the winter months having the lowest concentrations of chlorophyll and FCB. Statistical differences between the stormwater pond and the tidal creek were also noted within seasons. The tidal creek had higher FCB levels than the stormwater pond in the spring and summer, whereas the stormwater pond had higher chlorophyll levels than the tidal creek in the summer and fall seasons. Chlorophyll and FCB levels in the stormwater pond were significantly correlated with monthly average temperature and total rainfall. Pesticide concentrations were also significantly correlated with temperature and rainfall. Pesticide concentrations in the stormwater pond were significantly correlated with

  2. Tidal creek changes at the Sonoma Baylands restoration site

    USGS Publications Warehouse

    Dingler, John R.; Cacchione, David A.; ,

    1998-01-01

    Over the past 150 years, human activity has had a major impact on tidal wetlands adjoining the San Francisco Bay-Delta estuary Growing concern about the effect of this change on the ecology of the estuary has prompted Bay area managers to attempt to reclaim tidal wetlands. The Sonoma Baylands Restoration Project is designed to use dredge material to convert 348 acres from farmland to wetland. This paper describes changes to a tidal creek that flows from that restoration site to San Pablo Bay (north San Francisco Bay) through an existing tidal wetland during different phases of the project. Hydrologic measurements near the bottom of the creek and cross-creek profiles show how the creek responded to non-tidal flow conditions introduced by filling the site with dredge materials. At the time of this study, the creek had deepened by approximately 40 cm but had not widened.

  3. Tidally influenced alongshore circulation at an inlet-adjacent shoreline

    USGS Publications Warehouse

    Hansen, Jeff E.; Elias, Edwin P.L.; List, Jeffrey H.; Erikson, Li H.; Barnard, Patrick L.

    2013-01-01

    The contribution of tidal forcing to alongshore circulation inside the surfzone is investigated at a 7 km long sandy beach adjacent to a large tidal inlet. Ocean Beach in San Francisco, CA (USA) is onshore of a ∼150 km2 ebb-tidal delta and directly south of the Golden Gate, the sole entrance to San Francisco Bay. Using a coupled flow-wave numerical model, we find that the tides modulate, and in some cases can reverse the direction of, surfzone alongshore flows through two separate mechanisms. First, tidal flow through the inlet results in a barotropic tidal pressure gradient that, when integrated across the surfzone, represents an important contribution to the surfzone alongshore force balance. Even during energetic wave conditions, the tidal pressure gradient can account for more than 30% of the total alongshore pressure gradient (wave and tidal components) and up to 55% during small waves. The wave driven component of the alongshore pressure gradient results from alongshore wave height and corresponding setup gradients induced by refraction over the ebb-tidal delta. Second, wave refraction patterns over the inner shelf are tidally modulated as a result of both tidal water depth changes and strong tidal flows (∼1 m/s), with the effect from currents being larger. These tidally induced changes in wave refraction result in corresponding variability of the alongshore radiation stress and pressure gradients within the surfzone. Our results indicate that tidal contributions to the surfzone force balance can be significant and important in determining the direction and magnitude of alongshore flow.

  4. Tidal-to-seasonal variability in the parameters of the carbonate system in a shallow tidal creek influenced by anthropogenic inputs, Rio San Pedro (SW Iberian Peninsula)

    NASA Astrophysics Data System (ADS)

    de la Paz, Mercedes; Gómez-Parra, Abelardo; Forja, Jesús

    2008-06-01

    The main objective of the present study is to assess the temporal variability of the carbonate system, and the mechanisms driving that variability, in the Rio San Pedro, a tidal creek located in the Bay of Cadiz (SW Iberian Peninsula). This shallow tidal creek is affected by effluents of organic matter and nutrients from surrounding marine fish farms. In 2004, 11 tidal samplings, seasonally distributed, were carried out for the measurement of total alkalinity (TA), pH, dissolved oxygen and Chlorophyll- a (Chl- a) using a fixed station. In addition, several longitudinal samplings were carried out both in the tidal creek and in the adjacent waters of the Bay of Cadiz, in order to obtain a spatial distribution of the carbonate parameters. Tidal mixing is the main factor controlling the dissolved inorganic carbon (DIC) variability, showing almost conservative behaviour on a tidal time scale. The amplitude of the daily oscillations of DIC, pH and chlorophyll show a high dependence on the spring-neap tide sequence, with the maximum amplitude associated with spring tides. Additionally, a marked seasonality has been found in the DIC, pH and oxygen concentrations. This seasonality seems to be related to the increase in metabolic rates with the temperature, the alternation of storm events and high evaporation rates, together with intense seasonal variability in the discharges from fish farms. In addition, the export of DIC from the Rio San Pedro to the adjacent coastal area has been evaluated using the tidal prism model, obtaining a net export of 1.05×10 10 g C yr -1.

  5. Salt transport in a tidal canal, West Neck Creek, Virginia

    USGS Publications Warehouse

    Bales, Jerad D.; Skrobialowski, Stanley C.; ,

    1993-01-01

    Flow and stability were monitored during 1989-92 in West Neck Creek, Virginia, which provides a direct hydraulic connection between the saline waters of Chesapeake Bay and the relatively fresh waters of Currituck Sound, North Carolina. Flow in the tidal creek was to the south 64 percent of the time, but 80 percent of the southward flows were less than 40 cubic feet per second. The highest flows were associated with rain storms. Salinity ranged from 0.1 parts per thousand to 24.5 per thousand, and the highest salinities were observed during periods of sustained, strong northerly winds. Salt loads ranged from 302 tons per day to the north to 4,500 tons per day to the south.

  6. Tidal asymmetry in a tidal creek with mixed mainly semidiurnal tide, Bushehr Port, Persian Gulf

    NASA Astrophysics Data System (ADS)

    Hosseini, Seyed Taleb; Chegini, Vahid; Sadrinasab, Masoud; Siadatmousavi, Seyed Mostafa; Yari, Sadegh

    2016-03-01

    This study investigated the tidal asymmetry imposed by both the interaction of principal tides and the higher harmonics generated by distortions within a tidal creek network with mixed mainly semidiurnal tide in the Bushehr Port, Persian Gulf. Since velocity and water-level imposed by principal triad tides K1-O1-M2 are in quadrature, duration asymmetries during a tidal period in this short, shallow inverse estuary should be manifest as skewed velocities. The principal tides produce periodic asymmetries including a strong ebb-dominance and a weak flood-dominance condition during spring and neap tides respectively. The higher harmonics induced by nonlinearities engender a flood-dominance condition where the convergence effects are higher than frictional effects, and an ebbdominance condition where intertidal storage are extended. Since the triad K1-O1-M2 driven asymmetry is not overcome by higher harmonics close to the mouth, the periodic asymmetry dominates within the creek in which higher harmonics reinforce the weak flood-dominance (strong ebb-dominance) condition in the convergent channel (divergent area). Also, the maximum flood and the maximum ebb from all harmonic constituents occurred close to high water slack time during both spring and neap tides in this short creek. Since occational wetting of intertidal areas happened close to the high water (HW) time during spring tide, the water level flooded slowly close to the HW time of the spring tide.

  7. Analysis of nodal point pollution, variability, and sustainability in mesohaline tidal creeks.

    PubMed

    Muller, Andrew; Muller, Diana

    2014-08-15

    Mesohaline tidal creeks are critical since they may lie at the crossroads of aquatic habitat and urban/sub-urban pressures. The emphasis of this study was to determine the water quality stressor variations within and between tidal creeks and determine whether they serve as nodes of pollutants into the sub-estuary. Measurements of water quality stressors were conducted over a six-year period. The study revealed that characterizing the variability of individual tidal creeks is critical to understanding the process and impacts of stressors in sub-estuarine environments and that the tidal creeks are actually nodal points of sediment and nutrient pollution. This results in hypoxia being controlled within tidal creeks rather than being imported from the parent estuary. The calculated metrics were then used to create a Sustainability Characterization Map. Methods incorporated in this study would be of value to restoration managers, and in the decision-making process of urban and suburban watershed planners.

  8. Fish communities of a disturbed mangrove wetland and an adjacent tidal river in Palmar, Ecuador

    NASA Astrophysics Data System (ADS)

    Shervette, V. R.; Aguirre, W. E.; Blacio, E.; Cevallos, Rodrigo; Gonzalez, Marcelo; Pozo, Francisco; Gelwick, F.

    2007-03-01

    Coastal Ecuador has lost 20-30% of mangrove wetlands over the past 30 years. Such habitat loss can impair the ecological functions of wetlands. A paucity of information exists concerning mangrove fish communities of Ecuador. In this study we identify the fish community of the remaining mangrove wetland in Palmar, Ecuador. Fish were sampled in the dry season of 2003 and the wet season of 2004 by seining in mangrove creeks and Main channel of Rio Palmar. For comparison, an adjacent tidal river without mangroves, Rio Javita, was also sampled. We collected a total of 12,231 individuals comprising 36 species in 16 families from Rios Palmar and Javita. Gobiidae (7 species) was the most diverse family for mangrove sites followed by Gerreidae (5 species) and Engraulidae (4 species). A total of 34 species were collected in the mangrove wetland, 21 of which were exclusive to the mangroves including three species of juvenile snook (Centropomidae), indicating that the mangrove habitat of Palmar may provide nursery habitat for these economically valued species. In Rio Javita, Carangidae (3 species) was the most diverse family followed by Engraulidae and Gerreidae (2 species each). A total of 14 species were collected in the tidal river, only two of which were exclusive to the river. Multivariate analyses of fish community data indicated significant differences in community composition between the mangrove creeks and the tidal river and between seasons in both. Juvenile white mullet, Mugil curema, were collected in high relative abundance in both Rios Palmar and Javita, as was the tropical silverside Atherinella serrivomer an ecologically important species. Although Rios Palmar and Javita are characterized by relatively low fish species richness compared to other tropical estuarine systems, they appear to provide an important habitat for several economically and ecologically valued species.

  9. Tidal Flooding and Vegetation Patterns in a Salt Marsh Tidal Creek Imaged by Low-altitude Balloon Aerial Photography

    NASA Astrophysics Data System (ADS)

    White, S. M.; Madsen, E.

    2013-12-01

    Inundation of marsh surfaces by tidal creek flooding has implications for the headward erosion of salt marsh creeks, effect of rising sea levels, biological zonation, and marsh ecosystem services. The hydroperiod; as the frequency, duration, depth and flux of water across the marsh surface; is a key factor in salt marsh ecology, but remains poorly understood due to lack of data at spatial scales relevant to tracking the spatial movement of water across the marsh. This study examines how hydroperiod, drainage networks, and tidal creek geomorphology on the vegetation at Crab Haul Creek. Crab Haul Creek is the farthest landward tidal basin in North Inlet, a bar-built estuary in South Carolina. This study measures the hydroperiod in the headwaters Crab Haul Creek with normal and near-IR photos from a helium balloon Helikite at 75-100 m altitude. Photos provide detail necessary to resolve the waterline and delineate the hydroperiod during half tidal cycles by capturing the waterline hourly from the headwaters to a piezometer transect 260 meters north. The Helikite is an ideal instrument for local investigations of surface hydrology due to its maneuverability, low cost, ability to remain aloft for extended time over a fixed point, and ability to capture high-resolution images. Photographs taken from aircraft do not provide the detail necessary to determine the waterline on the marsh surface. The near-IR images make the waterline more distinct by increasing the difference between wet and dry ground. In the headwaters of Crab Haul Creek, individual crab burrows are detected by automated image classification and the number of crab burrows and their spatial density is tracked from January-August. Crab burrows are associated with the unvegetated region at the creek head, and we relate their change over time to the propagation of the creek farther into the tidal basin. Plant zonation is influenced by the hydroperiod, but also may be affected by salinity, water table depth, and

  10. The Effect of Oyster Reef Morphology on Particulate Transfer in a North Carolina Tidal Creek

    NASA Astrophysics Data System (ADS)

    Lemon, M. G.; Posey, M.; Mallin, M.; Alphin, T.

    2014-12-01

    The eastern oyster (Crassostrea virginica) is a vital ecosystem engineer species, providing a number of ecosystem services that structure and maintain estuarine environments through the construction of large, hard-bottom reef complexes. Through suspension feeding, oysters clear the water column of particulates, leading to decreased suspended material and enhanced benthic pelagic coupling. Past field studies have indicated the potential importance of the physical reef structure in regulating the transfer of particulate material in the seston. In order to directly assess the existence of the physical reef effect, multiple field experiments were performed in a small tidal creek estuary along the south eastern coast of North Carolina. Comparison of clearance rates derived from two different in situ methods, one accounting for the physical structure of the oyster reef in addition to oyster filtration and one looking at oyster filtration alone, indicate that the reef structure may increase the amount of particulate removal performed by the reef by more than 4 times the removal performed by oyster filtration alone. A defaunation experiment was performed by eliminating the live component of the oyster reef and comparing particulate transfer of this defaunated transect to that of an adjacent faunated transect. The defaunated transect had reduced but not significantly lower material removal when compared to the faunated transect prior to defaunation. Results from short and long term sediment collection and flow velocity measurements indicate that the physical effect of oyster reefs is strong over short temporal scales (days) but is much smaller when evaluated over longer time periods (months). Generally, large silt and small sand sized material is permanently removed from the seston due to the interaction of oyster reef structure and tidal flows, however the transfer of small and medium sized silt grains is only slowed down by the presence of large reef complexes. This

  11. Assessment and monitoring of nutrient loading in the sediments of tidal creeks receiving shrimp farm effluent in Quang Ninh, Vietnam.

    PubMed

    Bui, Thuyet D; Luong-Van, Jim; Maier, Stefan W; Austin, Chris M

    2013-10-01

    Coastal shrimp farming may lead to the contamination of sediments of surrounding estuarine and marine ecosystems as shrimp farm effluent often contains high levels of pollutants including a range of organic compounds (from uneaten feed, shrimp feces, and living and dead organisms) which can accumulate in the sediments of receiving waterways. The assessment and monitoring of sediment quality in tidal creeks receiving shrimp farm effluent can support environmental protection and decision making for sustainable development in coastal areas since sediment quality often shows essential information on long-term aquatic ecosystem health. Within this context, this paper investigates nutrient loadings in the sediments of tidal creeks receiving shrimp farm effluent in Quang Ninh, Vietnam, which now have a high concentration of intensive and semi-intensive shrimp farms. Sediment samples taken from inside creek sections directly receiving effluent from concentrated shrimp farms (IEC), from main creeks adjacent to points of effluent discharge outside concentrated shrimp farms (OEC), and few kilometers away from shrimp farms (ASF) as reference sites were collected and analyzed before and after shrimp crops to investigate spatial and temporal variation. The results showed that there were statistically significant differences in the concentrations of total nitrogen, total phosphorus, and total organic carbon among IEC, OEC, and ASF sites while the seasonal variation being limited over study times. A sediment nutrient index (SNI) computed from coefficient scores of the factor analysis efficiently summarizes sediment nutrient loads, which are high, albeit quite variable, in canals directly receiving effluents from farms but then decline sharply with distance from shrimp farms. The visualization and monitoring of sediment quality data including SNI on maps can strongly support managers to manage eutrophication at concentrated shrimp farming areas, contributing to sustainable

  12. Utilization by fishes of the Alviso Island ponds and adjacent waters in south san francisco bay following restoration to tidal influence

    USGS Publications Warehouse

    Saiki, M.K.; Mejia, F.H.

    2009-01-01

    Earthen levees of three isolated salt ponds known locally as the Alviso Island Ponds were intentionally breached in March 2006 to allow tidal exchange of the ponds with water from Coyote Creek. The water exchange transformed the previously fishless hypersaline ponds into lower salinity habitats suitable for fish life. This study documented fish utilization of the ponds, adjacent reaches of Coyote Creek, and an upstream reach in nearby Artesian Slough during May-July 2006. By the time the study was initiated, water quality conditions in the ponds were similar to conditions in adjacent reaches of Coyote Creek. The only variable exhibiting a strong gradient within the study area was salinity, which increased progressively from upstream to downstream in Coyote Creek. A total of 4,034 fish represented by 18 species from 14 families was caught during the study. Judging from cluster analysis of presence-absence data that excluded rare fish species, the 10 sampling units (3 ponds, 6 reaches in Coyote Creek, and 1 reach in Artesian Slough) formed two clusters or groups, suggesting two species assemblages. The existence of two groups was also suggested by ordination with non-metric multidimensional scaling (NMS). One group, which was composed of the three ponds and four of the lowermost reaches of Coyote Creek, was characterized by mostly estuarine or marine species (e.g., topsmelt, Atherinops affinis; northern anchovy, Engraulis mordax; and longjaw mudsucker, Gillichthys mirabilis). The second group, which was composed of the two uppermost reaches of Coyote Creek and the one reach of Artesian Slough, was characterized by freshwater species (e.g., Sacramento sucker, Catostomus occidentalis) and by an absence of the estuarine/marine species noted in the first assemblage. Judging from a joint plot of selected water quality variables overlaying the ordination results, salinity was the only important variable associated with spatial distribution of fish species. Water

  13. Saltmarsh pool and tidal creek morphodynamics: Dynamic equilibrium of northern latitude saltmarshes?

    NASA Astrophysics Data System (ADS)

    Wilson, Carol A.; Hughes, Zoe J.; FitzGerald, Duncan M.; Hopkinson, Charles S.; Valentine, Vinton; Kolker, Alexander S.

    2014-05-01

    Many saltmarsh platforms in New England and other northern climates (e.g. Canada, northern Europe) exhibit poor drainage, creating waterlogged regions where short-form Spartina alterniflora dominates and stagnant pools that experience tidal exchange only during spring tides and storm-induced flooding events. The processes related to pool formation and tidal creek incision (via headward erosion) that may eventually drain these features are poorly understood, however it has been suggested that an increase in pool occurrence in recent decades is due to waterlogging stress from sea-level rise. We present evidence here that saltmarshes in Plum Island Estuary of Massachusetts are keeping pace with sea-level rise, and that the recent increase in saltmarsh pool area coincides with changes in drainage density from a legacy of anthropogenic ditching (reversion to natural drainage conditions). Gradients, in addition to elevation and hydroperiod, are critical for saltmarsh pool formation. Additionally, elevation and vegetative changes associated with pool formation, creek incision, subsequent drainage of pools, and recolonization by S. alterniflora are quantified. Pool and creek dynamics were found to be cyclic in nature, and represent platform elevation in dynamic equilibrium with sea level whereby saltmarsh elevation may be lowered (due to degradation of organic matter and formation of a pool), however may be regained on short timescales (101-2 yr) with creek incision into pools and restoration of tidal exchange. Rapid vertical accretion is associated with sedimentation and S. alterniflora plant recolonization.

  14. Water use patterns of estuarine vegetation in a tidal creek system.

    PubMed

    Wei, Lili; Lockington, David A; Poh, Seng-Chee; Gasparon, Massimo; Lovelock, Catherine E

    2013-06-01

    Water availability is a key determinant of the zonation patterns in estuarine vegetation, but water availability and the use of different water sources over space and time are not well understood. We have determined the seasonal water use patterns of riparian vegetation over an estuarine ecotone. Our aim was to investigate how the water use patterns of estuarine vegetation respond to variations in the availability of tidal creek water and rain-derived freshwater. The levels of natural stable isotopes of oxygen and hydrogen were assessed in the stem of the mangrove Avicennia marina (tall and scrub growth forms), Casuarina glauca and Melaleuca quinquenervia that were distributed along transects from river/creek-front towards inland habitats. The isotopic composition of plant tissues and the potential water sources were assessed in both the wet season, when freshwater from rainfall is present, and the dry season, when mangrove trees are expected to be more dependent on tidal water, and when Casuarina and Melaleuca are expected to be dependent on groundwater. Our results indicate that rainwater during the wet season contributes significantly to estuarine vegetation, even to creek-side mangroves which are inundated by tidal creek water daily, and that estuarine vegetation depends primarily on freshwater throughout the year. In contrast, high intertidal scrub mangroves were found to use the greatest proportion of tidal creek water, supplemented by groundwater in the dry season. Contrary to prediction, inland trees C. glauca and M. quinquenervia were found also to rely predominantly on rainwater--even in the dry season. The results of this study reveal a high level of complexity in vegetation water use in estuarine settings.

  15. Sediment Transport Processes in a West-central Florida Open Marine Marsh Tidal Creek; the Role of Tides and Extra-tropical Storms

    NASA Astrophysics Data System (ADS)

    Leonard, Lynn A.; Hine, Albert C.; Luther, Mark E.; Stumpf, Richard P.; Wright, Eric E.

    1995-08-01

    The extensive open marine marshes on Florida's Gulf of Mexico coast constitute one of the largest continuous coastal marsh systems in the U.S.A. and are characterized by (1) the absence of an apparent modern or relict sediment supply, (2) a thin 1-2 m sediment veneer overlying highly karstified bedrock and (3) both low wave and low tidal energy regimes. More importantly, the Florida open marine marsh system appears to be keeping pace with current rates of sea-level rise in spite of a limited inorganic sediment supply and low tidal energies. Although the magnitudes and directions of suspended solid transport and the processes controlling these transports have been rigorously documented for other U.S.A. marsh systems, they have not been documented in the Florida marsh system. Total suspended solid (TSS) concentrations, current speeds and water levels were monitored in Cedar Creek, Florida, so that the TSS loads could be calculated and the processes exerting control over material exchange could be determined. Both TSS concentration and load are modulated by spring/neap variations and time-velocity asymmetries in the tidal currents. Concentrations at the creek mouth increase by as much as two orders of magnitude during strong wind events due to the presence of waves; however, large net sediment loads appear to be related to the coupled effects of waves and large tidal prisms. Waves initially mobilize sediments in the adjacent embayment but increased tidal prisms, and the associated higher velocities, are requisite for transport of this material further into the creek. Large tidal prisms may be the result of astronomically high tides or meteorologically forced tides. In Cedar Creek, the most important meteorological events affecting sedimentary processes are extra-tropical storms. This is because they occur at much higher frequencies than tropical storms and hurricanes, even though the latter are more potent and potentially could transport greater amounts of material

  16. Influence of moon phase on fish assemblages in estuarine mangrove tidal creeks.

    PubMed

    Ramos, J A A; Barletta, M; Dantas, D V; Lima, A R A; Costa, M F

    2011-01-01

    Significant differences in the composition of fish assemblages during different moon phases were detected in mangrove tidal creeks of the Goiana Estuary. The numbers of Zabaleta anchovy Anchovia clupeoides, Tarpon snook Centropomus pectinatus and Guavina Guavina guavina as well as at least 15 other species showed significant changes according to moon phase and were higher in terms of individuals (32%) and mass (34%) during the new moon.

  17. Development of a data management framework in support of southeastern tidal creek research.

    PubMed

    White, David L; Wolf, Danna; Porter, Dwayne E; Sanger, Denise M; Riekerk, George H M; DiDonato, Guy; Holland, A Fred; Dabney, David

    2009-03-01

    The NOAA Center of Excellence for Oceans and Human Health Initiative (OHHI) at the Hollings Marine Laboratory (HML) is developing a data management framework that supports an integrated research program across scientific disciplines. The primary focus of the database is to support environmental research focused on tidal creek watershed systems. Specifically, the current data holdings include physical water quality parameters, nutrients, pathogens, chemical contaminants, benthic and nekton species abundances and human dimensions data from Georgia, North Carolina and South Carolina dating to 1994. These data are not from a single long-term research project but are derived from several state and federal research programs and integrated into a common database model to support current research being conducted under the OHHI program at HML. The Tidal Creek database was developed with the intent to support a well documented and open system, thus metadata elements from common metadata standards including the Dublin Core ISO 15836:2003 and Federal Geographic Data Committee (FGDC-STD-001-1998) are components of the database model. The result is a semantic database framework with descriptive ancillary data at the record level including methods, investigator names, date, locations and other descriptive elements. The primary users of the database are project personnel to meet analytical needs. The database is also available through a number of web-based applications that are designed to give users the necessary information to evaluate and access data. In addition, data can be accessed with Open Geospatial Consortium (OGC) standards, and species records and abundances are being made available to the Ocean Biogeographic Information System (OBIS). Overall, the Tidal Creek database summarizes the response of tidal creeks and watersheds to coastal development, and serves as a repository for environmental, demographic, and socioeconomic data in the Southeast.

  18. Nocturnal Fish Use of New Jersey Marsh Creek and Adjacent Bay Shoal Habitats

    NASA Astrophysics Data System (ADS)

    Rountree, R. A.; Able, K. W.

    1997-06-01

    Night-time sampling with gill nets in the Little Egg Harbor estuary revealed a component of the estuarine fish fauna, hitherto poorly documented, which is comprised of relatively large size classes of juvenile and adult life history stages. The fishesMustelus canis, Pomatomus saltatrix, Paralichthys dentatus, Brevoortia tyrannus, Prionotus evolansandAlosa mediocriswere the most abundant fishes captured. These observations suggest that Mid-Atlantic Bight estuaries are important nurseries for juvenile stages beyond the first year, as well as for the young of the year (YOY). Although many other studies emphasise the importance of estuaries as nurseries for YOY stages, the importance of estuaries to later juvenile life stages has been largely overlooked. This component of estuarine fish fauna has been poorly represented in previous North American studies because of probable gear avoidance, and because most studies are conducted primarily during the day. The authors hypothesise that these later juvenile stages are likely to be important estuarine faunal components in other geographic regions, as well as in the Mid-Atlantic Bight. A descriptive comparison of catches between ebb and flood tide stages, and between bay shoal and tidal marsh creek habitats, suggests that later juvenile and adult stages of several species make tidal migrations into shallow estuarine habitats, such as shoals and marsh creeks, during the night hours.

  19. Benthic macroinvertebrate communities affected by multiple stressors within tidal creeks in northeastern USA harbors

    SciTech Connect

    Papageorgis, C.; Murray, M.; Danis, C.; Yates, L.

    1995-12-31

    Surveys of water quality, substrate quality and benthic macroinvertebrates were conducted in a variety of tidal creeks located in the vicinity of a municipal solid waste landfill prior to the construction of a leachate collection system. In-Situ water quality data indicated high water temperatures and low dissolved oxygen values along with high turbidites. Sediment chemistry data indicated that all sediment within the study area exceed USEPA heavy metal criteria. Grain size and salinity data indicate that the study area lies within the Mesohaline Mud habitat class. Water quality data remained within similar concentrations with respect to indicators of leachate. The benthic macroinvertebrate community was consistently dominated by opportunistic Polychaete and Oligochaete worms. Both Shannon diversity and Rarefaction curves were used to evaluate trends in species diversity over time. The study includes a comparison to data obtained by USEPA R-EMAP monitoring programs. While large scale biomonitoring programs do not focus on small tidal creeks this study provides useful data regarding baseline benthic communities within tidal creeks affected by multiple stressors to include previous exposure and potential exposure to oil spills, continued point and non-point municipal and industrial wastewater discharges and physical stressors such as elevated water temperatures, homogeneous silt/clay substrate, and depressed dissolved oxygen values.

  20. Marsh Pool and Tidal Creek Morphodynamics: Dynamic Equilibrium of New England Saltmarshes?

    NASA Astrophysics Data System (ADS)

    Wilson, C.; FitzGerald, D. M.; Hughes, Z. J.

    2012-12-01

    Under natural conditions, high saltmarsh platforms in New England exhibit poor drainage, creating waterlogged pannes (where short-form Spartina alterniflora dominates) and stagnant pools that experience tidal exchange only during spring tides and storm-induced flooding events. It is well accepted that a legacy of ditching practices (either for agriculture or mosquito control purposes) provide "overdrainage" of saltmarshes (after Redfield, 1972) and a shift in biogeochemical conditions: lowering of groundwater tables, aeration of soil, and decrease in preserved belowground biomass. Analysis of historical imagery in the Plum Island Estuary of Massachusetts reveals closure and decrease in length of anthropogenic ditches in recent decades is closely linked to marsh pool evolution. Field analyses including stratigraphic transects and elevation surveys suggest these marshes are reverting to natural drainage conditions. Further, an important dynamic interaction exists between saltmarsh pools and natural tidal creeks: creeks incise into pool areas, causing drainage of the pools, and formation of an unvegetated mudflat which can be rapidly recolonized by halophytic Spartina alterniflora vegetation. It was determined that pool and creek dynamics are cyclic in nature. The marsh platform is in dynamic equilibrium with respect to elevation and sea-level whereby marsh elevation may be lost (due to degradation of organic matter and formation of a pool) however may be regained (by creek incision into pools, restoration of tidal exchange, and rapid vertical accretion with Spartina alterniflora recolonization. Since vertical accretion in saltmarshes is a function of both organic and inorganic contributions to the marsh subsurface, it is hypothesized that cannibalization of existing muds is supplying inorganic material in this sediment starved system.

  1. Continuous Tidal Streamflow and Gage-Height Data for Bass and Cinder Creeks on Kiawah Island, South Carolina, September 2007

    USGS Publications Warehouse

    Conrads, Paul A.; Erbland, John W.

    2009-01-01

    A three-dimensional model of Bass and Cinder Creeks on Kiawah Island, South Carolina, was developed to evaluate methodologies for determining fecal coliform total maximum daily loads for shellfish waters. To calibrate the model, two index-velocity sites on the creeks were instrumented with continuous acoustic velocity meters and water-level sensors to compute a 21-day continuous record of tidal streamflows. In addition to monitoring tidal cycles, streamflow measurements were made at the index-velocity sites, and tidal-cycle streamflow measurements were made at the mouth of Bass Creek and on the Stono River to characterize the streamflow dynamics near the ocean boundary of the three-dimensional model at the beginning, September 6, 2007, and end, September 26, 2007, of the index-velocity meter deployment. The maximum floodtide and ebbtide measured on the Stono River by the mouth of Bass Creek for the two measurements were -155,000 and 170,000 cubic feet per second (ft3/s). At the mouth of Bass Creek, the maximum floodtide and ebbtide measurements during the 2 measurement days were +/-10,200 ft3/s. Tidal streamflows for the 21-day deployment on Bass Creek ranged from -2,510 ft3/s for an incoming tide to 4,360 ft3/s for an outgoing tide. On Cinder Creek, the incoming and outgoing tide varied from -2,180 to 2,400 ft3/s during the same period.

  2. Temperature anomalies in the Lower Suwannee River and tidal creeks, Florida, 2005

    USGS Publications Warehouse

    Raabe, Ellen A.; Bialkowska-Jelinska, Elzbieta

    2007-01-01

    Temperature anomalies in coastal waters were detected with Thermal Infrared imagery of the Lower Suwannee River (LSR) and nearshore tidal marshes on Florida’s Gulf Coast. Imagery included 1.5-m-resolution day and night Thermal Infrared (TIR) and 0.75-m-resolution Color Infrared (CIR) imagery acquired on 2-3 March 2005. Coincident temperature readings were collected on the ground and used to calibrate the imagery. The Floridan aquifer is at or near the land surface in this area and bears a constant temperature signature of ~ 22 degrees Celsius. This consistent temperature contrasts sharply with ambient temperatures during winter and summer months. Temperature anomalies identified in the imagery during a late-winter cold spell may be correlated with aquifer seeps. Hot spots were identified as those areas exceeding ambient water temperature by 4 degrees Celsius or more. Warm-water plumes were also mapped for both day and night imagery. The plume from Manatee Spring, a first-order magnitude spring, influenced water temperature in the lower river. Numerous temperature anomalies were identified in small tributaries and tidal creeks from Shired Island to Cedar Key and were confirmed with field reconnaissance. Abundant warm-water features were identified along tidal creeks south of the Suwannee River and near Waccasassa Bay. Features were mapped in the tidal creeks north of the river but appear to be less common or have lower associated discharge. The imagery shows considerable promise in mapping coastal-aquifer seeps and understanding the underlying geology of the region. Detection of seep locations may aid research in groundwater/surface-water interactions and water quality, and in the management of coastal habitats.

  3. Nonlinear Tidal Distortion and Low Frequency Residual Effects in a Coastal Creek

    NASA Astrophysics Data System (ADS)

    Jachec, S. M.; Hansell, H. C.

    2012-12-01

    A 62 day observational campaign in the spring 2011, recorded free surface and meteorological observations used to determine hydrodynamic conditions of an area in the northern region of Mosquito Lagoon, FL. Mean water level ranges at instrument locations decrease from 0.35 to 0.22 m moving further from the primary inlet. A harmonic analysis revealed mean extracted tidal ranges at the former stations decreasing from 0.34 to 0.21 m. Nonlinear distortion increases with distance into the system, with a maximum tidal range decrease of 0.13 m and high tide time lag of 0.89 hrs between extreme stations. Ebb durations averaged 1 hr longer than flood, indicating a flood-dominant system. Spectral and cross-spectral analyses showed significant coherence between wind and non-tidal fluctuations in the low frequency regime. Using a modified conservation of mass equation, flow calculations reveal a partitioning of the flow between tides and winds.; Study site: Mosquito Lagoon, FL. ; Tidal amplitude attenuation of M2 and M4 tides through creek.

  4. Hydrographic characterization of two tidal creeks with implications for watershed land use, flushing times, and benthic production

    USGS Publications Warehouse

    Buzzelli, C.; Holland, Austin F.; Sanger, D.M.; Conrads, P.C.

    2007-01-01

    Many coastal ecosystems are undergoing anthropogenic stress from large increases in population and urbanization. In many regions changes in freshwater and material inputs to the coastal zone are altering the biogeochemical and biological capacities of ecosystems. Despite increased watershed inputs, large tidal volumes and flushing indicative of macrotidal estuaries can modulate the fate of introduced materials masking some of the symptoms of eutrophication. The Land Use Coastal Ecosystem Study (LU-CES) examined linkages between land use and environmental properties of Malind and Okatee Creeks in South Carolina from 2001 to 2004. The objectives of this particular study were to assess the hydrography of the two macrotidal creek ecosystems, explore differences in dissolved oxygen (DO), and develop a better understanding of the variations in primary and benthic secondary production in southeastern creek ecosystems. Depth, pH, salinity, and DO were reduced and more variable in Malind Creek than in Okatee Creek, although both creeks had strong semidiurnal frequencies in salinity time signatures. While time series analyses of DO saturation in Malind Creek revealed a dominant semidiurnal pattern, Okatee Creek had a distinctly diel DO pattern. The strongly semidiurnal fluctuations in DO and reduced flushing time indicated that biological processes were not fast enough to influence DO in Malind Creek. The Okatee Creek system had a much greater storage volume, a wider marsh, and a dominant 25-h DO frequency. These attributes contributed to an estimated 8-10 times more phytoplankton-based carbon in Okatee Creek and twice the annual benthic production. As expected from their proximity to the upland, low surface area, and high organic content, both ecosystems were net heterotrophic. This fundamental understanding of tidal creek hydrography is being used to help define linkages among differential watershed land uses, flushing characteristics, and levels of biological production

  5. 76 FR 44602 - Notice of Temporary Closure of Roads and Trails on Public Lands Adjacent to Big Willow Creek in...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-26

    ... Bureau of Land Management Notice of Temporary Closure of Roads and Trails on Public Lands Adjacent to Big Willow Creek in Payette County, ID AGENCY: Bureau of Land Management, Interior. ACTION: Notice of... in effect on public lands administered by the Four Rivers Field Office, Bureau of Land...

  6. Tidal exchange of zooplankton between Lough Hyne and the adjacent coast

    NASA Astrophysics Data System (ADS)

    Rawlinson, K. A.; Davenport, J.; Barnes, D. K. A.

    2005-01-01

    Plankton samples collected in November 2002, February, May and August 2003 were used to examine seasonal variation in tidal exchange of zooplankton biomass, abundance and species composition between Lough Hyne Marine Nature Reserve and the adjacent Atlantic coast. Micro- to mesozooplankton were collected by pump over 24-h sampling periods during spring and neap tides from the narrow channel connecting the semi-enclosed water body to the Atlantic. Sample biomass (dry weight) and total zooplankton abundance peaked in the summer and were lowest in winter, showing a positive relationship with temperature. Zooplankton biomass, total abundance and numbers of holo- and meroplankton revealed import during some diel cycles and export in others. However, the tidal import of these planktonic components was generally dominant, especially during May. The greatest import of numbers of holoplankters and meroplanktonic larvae occurred during May and August, respectively. There was no significant variation in sample biomass between periods of light and dark, but some variation in zooplankton abundance could be explained by this diel periodicity. Significant differences in sample assemblage composition between flood and ebb tide samples were always observed, except during winter neap tides. There was a net import of the copepods Temora longicornis and Oithona helgolandica and the larval stages of Mytilus edulis during spring and summer. Proceraea cornuta and Capitellid trochophores were imported during winter, and a hydrozoan of the genus Obelia during the spring spring tides. Seasonal export from the lough was shown by Pseudopolydora pulchra larvae (autumn and spring), Serpulid trochophores (autumn) and veligers of the bivalve Anomia ephippium (summer). It is suggested that the direction of tidal exchange of meroplanktonic taxa is related to the distribution of the adult populations. Copepod naupliar stages dominated the assemblages except during May spring tides when the copepod

  7. Comparative study of trophic organization of juvenile fish assemblages of three tidal creeks in a tropical semi-arid estuary.

    PubMed

    Figueiredo, G G A A; Pessanha, A L M

    2016-07-01

    A comparison of three tidal creeks assessed the effects of the hydrological regime on trophic organization in juvenile fish assemblages of 21 species in a tropical estuary in north-eastern Brazil. There were seven trophic guilds represented spatially. Zooplanktivore and zoobenthivore guilds dominated the lower estuary, whereas omnivores and detritivores dominated the upper estuary. In the rainy season, the zooplanktivore and omnivore guilds were more common throughout the estuary, but in the dry season, zoobenthivores and piscivores occurred throughout. The trophic organization results show that (1) there was a higher complexity in tidal creeks in the upper estuary compared with the first tidal creek in the lower region and (2) trophic linkages increased in the upper estuary, principally the number of omnivore and detritivore species. Spatial variation in trophic structure was primarily associated with differences in the location of the tidal creeks along the estuary, and this variability was partly attributed to fish species richness; the number of species increased towards the upper estuary, and additional species occupied different trophic levels or used additional resources. PMID:26693658

  8. Comparative study of trophic organization of juvenile fish assemblages of three tidal creeks in a tropical semi-arid estuary.

    PubMed

    Figueiredo, G G A A; Pessanha, A L M

    2016-07-01

    A comparison of three tidal creeks assessed the effects of the hydrological regime on trophic organization in juvenile fish assemblages of 21 species in a tropical estuary in north-eastern Brazil. There were seven trophic guilds represented spatially. Zooplanktivore and zoobenthivore guilds dominated the lower estuary, whereas omnivores and detritivores dominated the upper estuary. In the rainy season, the zooplanktivore and omnivore guilds were more common throughout the estuary, but in the dry season, zoobenthivores and piscivores occurred throughout. The trophic organization results show that (1) there was a higher complexity in tidal creeks in the upper estuary compared with the first tidal creek in the lower region and (2) trophic linkages increased in the upper estuary, principally the number of omnivore and detritivore species. Spatial variation in trophic structure was primarily associated with differences in the location of the tidal creeks along the estuary, and this variability was partly attributed to fish species richness; the number of species increased towards the upper estuary, and additional species occupied different trophic levels or used additional resources.

  9. METHODS OF EXPLORING METABOLIC STRUCTURE AND TAXONOMIC DIVERSITY RELATIONSHIPS BETWEEN BACTERIOPLANKTON AND PHYTOPLANKTON IN SALT MARSH TIDAL CREEKS

    EPA Science Inventory

    Bacterial metabolic diversity and phytoplankton community diversity were examined in eight shallow tidal creeks over a two-year period (1997-1998) within North Inlet estuary, South Carolina. The BIOLOG 96-well microplate method was used to assess metabolic diversity of bacteria, ...

  10. Hydrogeologic characteristics of the alluvial aquifer and adjacent deposits of the Fountain Creek valley, El Paso County, Colorado

    USGS Publications Warehouse

    Radell, Mary Jo; Lewis, Michael E.; Watts, Kenneth R.

    1994-01-01

    The alluvial aquifer in Fountain Creek Valley between Colorado Springs and Widefield is the source for several public-supply systems. Because of the importance of this aquifer, defining aquifer boundaries, areas where underflow occurs, and where Fountain Creek is hydraulically connected to the aquifer will greatly add to the understanding of the alluvial aquifer and management of the public- supply systems. Bedrock altitude, water-table altitude for October 1991, saturated thickness for October 1991, selected hydrogeologic sections in the alluvial aquifer and adjacent deposits of the Fountain Creek Valley, and estimated underflow rates are mapped or tabulated for the area between Colorado Springs and Widefield, Colorado. Results from test drilling indicate that the bedrock surface is highly irregular and that several ridges and buried channels exist in the study area. These features affect the direction of ground-water flow on a local scale. In places, a shale ridge prevents exchange of water between Fountain Creek and the aquifer. Generally, ground water flowed toward Fountain Creek during the study (June 1991 to September 1992) in response to relatively high hydraulic heads in the aquifer and the steep gradients on the boundaries of the study area. Water levels, which were measured monthly, varied little during the study, except in areas near pumping wells or adjacent to Fountain Creek. Hydraulic-conductivity values, estimated from 30 bail tests in wells completed in the alluvial aquifer, were used to determine underflow across the saturated boundaries of the alluvial aquifer. Estimated hydraulic-conductivity values range from 1 to about 1,300 feet per day; the larger values occur in the buried channel of the alluvial aquifer and the smaller values occur near the boundaries of the saturated alluvium. Estimated underflow into the study area exceeded underflow out of the study area by about 10 times. Gain-loss investigations along Fountain Creek indicated that the

  11. Altered mangrove wetlands as habitat for estuarine nekton: are dredged channels and tidal creeks equivalent?

    USGS Publications Warehouse

    Krebs, Justin M.; Brame, Adam B.; McIvor, Carole C.

    2007-01-01

    Hasty decisions are often made regarding the restoration of "altered" habitats, when in fact the ecological value of these habitats may be comparable to natural ones. To assess the "value" of altered mangrove-lined habitats for nekton, we sampled for 1 yr within three Tampa Bay wetlands. Species composition, abundance, and spatial distribution of nekton assemblages in permanent subtidal portions of natural tidal creeks and wetlands altered by construction of mosquito-control ditches and stormwater-drainage ditches were quantified through seasonal seine sampling. Results of repeated-measures analysis of variance and ordination of nekton community data suggested differences in species composition and abundance between natural and altered habitat, though not consistently among the three wetlands. In many cases, mosquito ditches were more similar in assemblage structure to tidal creeks than to stormwater ditches. In general, mosquito ditches and stormwater ditches were the most dissimilar in terms of nekton community structure. These dissimilarities were likely due to differences in design between the two types of ditches. Mosquito ditches tend to fill in over time and are thus more ephemeral features in the landscape. In contrast, stormwater ditches are a more permanent altered habitat that remain open due to periodic flushing from heavy runoff. Results indicate that environmental conditions (e.g., salinity, current velocity, vegetative structure) may provide a more useful indication of potential habitat "value" for nekton than whether the habitat has been altered. The type of ditching is therefore more important than ditching per se when judging the habitat quality of these altered channels for fishes, shrimps and crabs. Planning should entail careful consideration of environmental conditions rather than simply restoring for restoration's sake.

  12. Variation in Prokaryotic Community Composition as a Function of Resource Availability in Tidal Creek Sediments▿

    PubMed Central

    Edmonds, Jennifer W.; Weston, Nathanial B.; Joye, Samantha B.; Moran, Mary Ann

    2008-01-01

    In anaerobic coastal sediments, hydrolytic and/or fermentative bacteria degrade polymeric material and produce labile intermediates, which are used by terminal metabolizers to complete the conversion of organic material to CO2. We used molecular approaches to evaluate the response of two bacterial terminal metabolizer groups from a coastal tidal creek sediments, sulfate reducers and methanogens, to controlled changes in carbon resource supply. Tidal creek sediment bioreactors were established in April and August 2004. For each date, intact sediment sections were continuously supplied with flowthrough seawater that was either unamended or amended with the high-molecular-weight polysaccharide dextran. Biogeochemical data indicate that the activity of fermenting bacteria and the terminal metabolizers was limited by organic carbon supply during both experiments, with a significant increase in net volatile fatty acid (VFA) production and rates of sulfate reduction and methanogenesis following dextran addition. Community composition (measured by using terminal restriction fragment length polymorphism analysis, and functional gene [dsrA, mcrA] clone libraries) changed from April to August. However, community composition was not different between amended and unamended cores within each month, despite the change in resource level. Moreover, there was no relationship between community richness and evenness with resource level. This lack of variation in community composition with C addition could be attributed to the dynamic environment these sediment communities experience in situ. Fluctuations in VFA concentrations are most likely very high, so that the dominant bacterial species must be able to outcompete other species at both high and low resource levels. PMID:18192417

  13. Apogean-perigean signals encoded in tidal flats at the fluvio-estuarine transition of Glacier Creek, Turnagain Arm, Alaska; implications for ancient tidal rhythmites

    USGS Publications Warehouse

    Greb, S.F.; Archer, A.W.; Deboer, D.G.

    2011-01-01

    Turnagain Arm is a macrotidal fjord-style estuary. Glacier Creek is a small, glacially fed stream which enters the estuary tangentially near Girdwood, Alaska. Trenches and daily sedimentation measurements were made in a mudflat along the fluvio-estuarine transition of Glacier Creek during several summers since 2003. Each year, the flats appear to erode during the winter and then accrete vertically in the spring and summer. In each of the years studied, tidal laminae in vertically thickening and thinning laminae bundles were deposited by twice daily tides in neap-spring tidal cycles. In 2004, bundles of thickening and thinning laminae couplets were noted in trenches cut into the flats. Five laminae bundles alternated between thicker and thinner bundles, corresponding to the perigean (high spring) and apogean (low spring) tides. Well-preserved apogean-perigean cycles have rarely been documented in modern tidal flat sediments. At this location, vertical accretion of tidal rhythmites with well-developed neap-spring cyclicity is possible because of the near-complete removal of the flat from the previous year, which creates accommodation space for vertical accretion without significant reworking. Macrotidal conditions, no reworking by infaunal invertebrates, protection from the main tidal channel by a gravel bar and protection from storm waves and fluvial erosion by a recess in the sedge marsh that surrounds the flats all aid in preservation of rhythmites during aggradation. The position of the flats relative to tidal range allows for accumulation of complete spring cycles and incomplete neap cycles. In the summer of 2004, apogee and perigee were closely aligned with the new and full moons, resulting in successive strong perigee and apogee tides which probably aided in the accumulation of successive thick-thin spring cycles encoding the apogean and perigean tidal cycle. The apogean-perigean signal was not observed in subsequent years. ?? 2011 The Authors.

  14. Faulted shoreline and tidal deposits in the Moenkopi Formation of the Grassy Trail Creek field, Utah

    SciTech Connect

    Allison, M.L. ); Lutz, S.J. )

    1991-06-01

    The Grassy Trail Creek field produces 40{degrees} API oil and minor gas from shallow marine sandstones of the Triassic Moenkopi Formation on the north-plunging nose of the San Rafael swell in central Utah. Production is controlled by a combination of stratigraphic variations and minor north-south-trending faults. Although fracture permeability enhances production of the reservoir, some faults act as barriers to fluid migration, segmenting the area into productive and dry fault blocks. Horizontal drilling techniques developed in this field in the early 1980s resulted in significantly better production. Log analyses indicate the main reservoir is a complex stack of this thin tidal channel sandstones. Isochore maps of the A and B zones indicate thickened meanders that form localized reservoir pods that are vertically offset. The distribution of isochore thicks appears to represent deposition along a northwest-southeast-trending shoreline fed by sediments from the northeast. There is potential for field extensions in similar deposits along this paleoshoreline. The Moenkopi Formation, long thought to be self-sourcing, may contain oil generated in Precambrian sediments equivalent to the Late Proterozoic Chuar Group. Presence of this older oil would have required migration from Precambrian sedimentary rocks surrounding the San Rafael swell.

  15. Effect of water quality indices on phytoplankton of a sluggish tidal creek in Lagos, Nigeria.

    PubMed

    Adesalu, T A; Nwankwo, D I

    2008-03-15

    The phytoplankton of a tidal creek in Lagos was investigated for six months (September 1998-February 1999). The physico-chemical environment was essentially neutral (pH 7.00-7.30), relatively more transparent (> 0.23 m), expressed higher conductivity (> 0.10 mS cm(-1)), higher chloride values (> 23.48 mg L(-1)), lower nitrate content (< 0.70 mg L(-1)), lower sulphate values (< 0.45 mg L(-1)) and phosphate values (< 0.12 mg L(-1)) in the dry months. In the wet months, September to November 1998, conductivity (< 0.16 mS cm(-1)), transparency (< 0.80 m), salinity (< 0.04%), dissolved oxygen (< 24.00 mg L(-1)), chloride (< 24.21 mg L(-1)) and phosphate (< 0.21 mg L(-1)) were recorded. The phytoplankton was dominated by diatoms (48 pennate forms and 23 centric forms). The other algal groups comprised six blue- green algae and six green algae. Species richness (d) was high in stations nearer the Lagos lagoon for the six sampling periods. Shannon-Weaver index (H1) was lowest in November 1998 and highest in October 1998 and February 1999 while evenness of species J was low (< 0.71) throughout the period. Higher phytoplankton biomass was recorded in the dry months than wet months. PMID:18814644

  16. Tidal, diel and semi-lunar changes in the faunal assemblage of an intertidal salt marsh creek

    NASA Astrophysics Data System (ADS)

    Hampel, Henrietta; Cattrijsse, Andre; Vincx, Magda

    2003-03-01

    The utilisation of a brackish estuarine marsh by nekton was investigated over a semi-lunar cycle in August 1994. Nekton migrating in and out of the intertidal creeks of the marsh 'Het Verdronken Land van Saeftinghe' in the Westerschelde estuary, SW Netherlands, was sampled passively during seven complete tidal cycles. Sampling one tidal cycle yielded three consecutive flood samples and four consecutive ebb samples. Sampling occurred every 2-3 days, covering diel, tidal and semi-lunar situations, thus allowing comparison of tidal, diel and semi-lunar influences on the composition of the intertidal fauna. Two different tidal-migration modes were observed. The mysid shrimp, Mesopodopsis slabberi, showed maximum abundance around high tide. For the remaining common species, the mysid ( Neomysis integer), the shrimp ( Palaemonetes varians), the crab ( Carcinus maenas) and the goby ( Pomatoschistus microps) and the amphipod ( Corophium volutator), highest densities were recorded during lower water heights. The faunal assemblage shifts between the different tidal stages. On two occasions, consecutive day and night samples were taken. Total densities were higher during the night samples. During spring tide, difference in community composition was noticed between the night and the day samples. During neap tide, day-night differences were less clear. Recorded total densities were highest during spring tide and lowest during neap tide. At maximum water levels, a drop in total density was observed. A shift in community composition occurred between spring and neap tides.

  17. The Relative Effects of Wave Climatology and Tidal Currents on Beach Processes Adjacent to a Major Tidal Inlet, Ocean Beach, San Francisco, California

    NASA Astrophysics Data System (ADS)

    Barnard, P. L.; Hanes, D. M.; Ruggiero, P.

    2004-12-01

    Identifying the processes that control the morphological evolution of beaches adjacent to tidal inlets is challenging due to the complex interactions between waves, currents, and bathymetry, each with high spatial and temporal variability. In the shadow of the large ebb tidal delta at the mouth of San Francisco Bay, CA, the wave refraction patterns at Ocean Beach are complex and the effects of the offshore wave climate on beach and nearshore morphology cannot be assessed simply by analyzing data from an offshore wave buoy. Instead, the United States Geological Survey has employed a multi-faceted approach that links wave data with numerical modeling, periodic three- dimensional topographic beach surveys, cross shore bathymetric surveys using personal watercraft, onshore grain-size analysis using a bed sediment camera, and a multi-beam survey covering the entire mouth of San Francisco Bay. Initial analyses demonstrate that the spatial distribution of wave energy and direction controls short-term (i.e. days to years) beach evolution, including the location of erosional "hot spots." These conclusions are supported by topographic LIDAR surveys that covered the study area in 1997, 1998 and 2002, bracketing the last major El Niño/ Southern Oscillation cycles. In this study, SWAN (Simulating WAves Nearshore) modeling is combined with high resolution bathymetry and high resolution beach surveys to quantify short-term morphological change and to provide links to nearshore processes. Initial SWAN results show a focusing of wave energy at the location of an erosional hot-spot on the southern end of Ocean Beach during the prevailing northwest swell. During El Niño winters, swell out of the west and southwest dominates the region, and although the wave energy is focused further to the north on Ocean Beach, the oblique wave approach sets up a strong northerly littoral drift, thereby starving the southern end of sediment, leaving it increasingly vulnerable to wave attack when

  18. Loading of fecal indicator bacteria in North Carolina tidal creek headwaters: hydrographic patterns and terrestrial runoff relationships.

    PubMed

    Stumpf, Curtis H; Piehler, Michael F; Thompson, Suzanne; Noble, Rachel T

    2010-09-01

    In the New River Estuary (NRE) in eastern North Carolina (NC), fecal indicator bacteria (FIB) levels exceed water quality standards, leading to closure of estuarine waters for shellfishing and classification of parts of the estuary as "impaired" per the Clean Water Act section 303(d) list. As a means to investigate fecal contamination and loading of FIB to the NRE, a continuous automated sampler (ISCO) outfitted with flow modules and water quality probes was placed in four first-order tidal creek headwaters. Total storm discharge and bacterial load for Escherichia coli (EC) and Enterococcus spp. (ENT) were calculated using graphical volumetric flow calculations and interpolation of FIB measurements over each storm's duration for 10 storms. Mean total load of 10(9)-10(12) EC and ENT cells (MPN) occurred over the course of each storm. Total storm loading, averaged across all storms, was as much as 30 and 37 times greater than equivalent duration of baseflow loading for EC and ENT, respectively. Within the first 30% of creek storm volume for all storms and all creeks combined, a mean cumulative load of only 37% and 44% of the total EC and ENT cells, respectively, was discharged, indicating these creeks are not demonstrating a 'first flush' scenario for FIB. The median storm Event Mean Concentrations (EMCs) were 6.37 × 10(2) and 2.03 × 10(2) MPN/100 mL, for EC and ENT, respectively, compared with median baseflow concentrations of 1.48 × 10(2) and 4.84 × 10(1) for EC and ENT, respectively, and were significantly different between base and storm flow events. FIB was correlated with TSS (weak), flow rate (strong), and different stages (base, rising, peak, and falling) of the hydrograph (strong). Pollutographs indicate large intra-storm variability of FIB, and the need for more intensive sampling throughout a storm in order to attain accurate FIB contaminant estimates. Instream sediment concentrations ranged from 5 to 478 (MPN/g) and 13 to 776 (MPN/g) for EC and ENT

  19. Effects of changing land use on the microbial water quality of tidal creeks.

    PubMed

    DiDonato, Guy T; Stewart, Jill R; Sanger, Denise M; Robinson, Brian J; Thompson, Brian C; Holland, A Frederick; Van Dolah, Robert F

    2009-01-01

    Population growth along the southeastern United States coast has precipitated the conversion of forested watersheds to suburban and urban ones. This study sampled creeks representing forested, suburban, and urban watersheds along a longitudinal gradient for indicators of water quality, including traditional indicator bacteria (fecal coliforms and enterococci) and alternative viral indicators (male-specific and somatic coliphages). Tested microorganisms were generally distributed with highest concentrations in creek headwaters and in more developed watersheds. The headwaters also showed the strongest predictive relationship between indicator concentrations and urbanization as measured by impervious cover. A seasonal pattern was observed for indicator bacteria but not for indicator viruses. Coliphage typing indicated the likely source of contamination was nonhuman. Results suggest that headwater creeks can serve as sentinel habitat, signaling early warning of public health concerns from land-based anthropogenic activities. This study also implies the potential to eventually forecast indicator concentrations under land use change scenarios.

  20. Tidal modulation of the hypoxia adjacent to the Yangtze Estuary in summer.

    PubMed

    Chen, Xiaofeng; Shen, Zhenyao; Li, Yangyang; Yang, Ye

    2015-11-15

    The influence of tide on the distribution of hypoxia adjacent to the Yangtze Estuary was investigated using a three-dimensional hydrodynamic eutrophication model. In the absence of tide, the hypoxic areal extent increased from 5226.75km(2) in the base model run to 19,514.25km(2), and it mainly occurred in the inner shelf region near the mouth of the Yangtze Estuary and in the inner part of Hangzhou Bay. During neap tide, the hypoxic areal extent further increased to cover 20,704.50km(2). Hypoxia first appeared to the southeast of Hangzhou Bay. During the neap to spring tide transition, the hypoxic areal extent decreased to 2430.00km(2) due to reduced stratification (2.65×10(-3)S(-2)) and the direction of the current. The hypoxic areal extent further decreased to 2319.75km(2) during spring tide along with increased current and reduced stratification. Also, hypoxia mainly appeared in the submarine valley. PMID:26330017

  1. Tidal modulation of the hypoxia adjacent to the Yangtze Estuary in summer.

    PubMed

    Chen, Xiaofeng; Shen, Zhenyao; Li, Yangyang; Yang, Ye

    2015-11-15

    The influence of tide on the distribution of hypoxia adjacent to the Yangtze Estuary was investigated using a three-dimensional hydrodynamic eutrophication model. In the absence of tide, the hypoxic areal extent increased from 5226.75km(2) in the base model run to 19,514.25km(2), and it mainly occurred in the inner shelf region near the mouth of the Yangtze Estuary and in the inner part of Hangzhou Bay. During neap tide, the hypoxic areal extent further increased to cover 20,704.50km(2). Hypoxia first appeared to the southeast of Hangzhou Bay. During the neap to spring tide transition, the hypoxic areal extent decreased to 2430.00km(2) due to reduced stratification (2.65×10(-3)S(-2)) and the direction of the current. The hypoxic areal extent further decreased to 2319.75km(2) during spring tide along with increased current and reduced stratification. Also, hypoxia mainly appeared in the submarine valley.

  2. Delineation of tidal scour through marine geophysical techniques at Sloop Channel and Goose Creek bridges, Jones Beach State Park, Long Island, New York

    USGS Publications Warehouse

    Stumm, Frederick; Chu, Anthony; Reynolds, Richard J.

    2001-01-01

    Inspection of the Goose Creek Bridge in southeastern Nassau County in April 1998 by the New York State Department of Transportation (NYSDOT) indicated a separation of bridge piers from the road bed as a result of pier instability due to apparent seabed scouring by tidal currents. This prompted a cooperative study by the U.S. Geological Survey with the NYSDOT to delineate the extent of tidal scour at this bridge and at the Sloop Channel Bridge, about 0.5 mile to the south, through several marine- geophysical techniques. These techniques included use of a narrow-beam, 200-kilohertz, research-grade fathometer, a global positioning system accurate to within 3 feet, a 3.5 to 7-kilohertz seismic-reflection profiler, and an acoustic Doppler current profiler (ADCP). The ADCP was used only at the Sloop Channel Bridge; the other techniques were used at both bridges. Results indicate extensive tidal scour at both bridges. The fathometer data indicate two major scour holes nearly parallel to the Sloop Channel Bridge -- one along the east side, and one along the west side (bridge is oriented north-south). The scour-hole depths are as much as 47 feet below sea level and average more than 40 feet below sea level; these scour holes also appear to have begun to connect beneath the bridge. The deepest scour is at the north end of the bridge beneath the westernmost piers. The east-west symmetry of scour at Sloop Channel Bridge suggests that flood and ebb tides produce extensive scour. The thickness of sediment that has settled within scour holes could not be interpreted from fathometer data alone because fathometer frequencies cannot penetrate beneath the sea-floor surface. The lower frequencies used in seismic-reflection profiling can penetrate the sea floor and underlying sediments, and indicate the amount of infilling of scour holes, the extent of riprap under the bridge, and the assemblages of clay, sand, and silt beneath the sea floor. The seismic- reflection surveys detected 2

  3. A tidal creek water budget: Estimation of groundwater discharge and overland flow using hydrologic modeling in the Southern Everglades

    NASA Astrophysics Data System (ADS)

    Michot, Béatrice; Meselhe, Ehab A.; Rivera-Monroy, Victor H.; Coronado-Molina, Carlos; Twilley, Robert R.

    2011-07-01

    Taylor Slough is one of the natural freshwater contributors to Florida Bay through a network of microtidal creeks crossing the Everglades Mangrove Ecotone Region (EMER). The EMER ecological function is critical since it mediates freshwater and nutrient inputs and controls the water quality in Eastern Florida Bay. Furthermore, this region is vulnerable to changing hydrodynamics and nutrient loadings as a result of upstream freshwater management practices proposed by the Comprehensive Everglades Restoration Program (CERP), currently the largest wetland restoration project in the USA. Despite the hydrological importance of Taylor Slough in the water budget of Florida Bay, there are no fine scale (˜1 km 2) hydrodynamic models of this system that can be utilized as a tool to evaluate potential changes in water flow, salinity, and water quality. Taylor River is one of the major creeks draining Taylor Slough freshwater into Florida Bay. We performed a water budget analysis for the Taylor River area, based on long-term hydrologic data (1999-2007) and supplemented by hydrodynamic modeling using a MIKE FLOOD (DHI, http://dhigroup.com/) model to evaluate groundwater and overland water discharges. The seasonal hydrologic characteristics are very distinctive (average Taylor River wet vs. dry season outflow was 6 to 1 during 1999-2006) with a pronounced interannual variability of flow. The water budget shows a net dominance of through flow in the tidal mixing zone, while local precipitation and evapotranspiration play only a secondary role, at least in the wet season. During the dry season, the tidal flood reaches the upstream boundary of the study area during approximately 80 days per year on average. The groundwater field measurements indicate a mostly upwards-oriented leakage, which possibly equals the evapotranspiration term. The model results suggest a high importance of groundwater contribution to the water salinity in the EMER. The model performance is satisfactory

  4. Mercury distribution in a mangrove tidal creek affected by intensive shrimp farming.

    PubMed

    Costa, B G B; Soares, T M; Torres, R F; Lacerda, L D

    2013-05-01

    In this study, the Hg distributions in water and sediments from a mangrove creek that receives intensive shrimp farming effluents were determined. The average dissolved and particulate Hg concentrations in the water varied from 3.1 to 9.2 ng L(-1) and from 4.4 to 9.4 ng L(-1), respectively. However, the Hg concentrations in the suspended particulate matter and the bottom sediments varied from 95.4 to 115.7 ng g(-1) and from 1.6 to 10.3 ng g(-1), respectively. A Ward quadratic distance cluster analysis based on the Hg concentrations and hydro- and geochemical parameters (oxygen, salinity, temperature, pH, and organic matter and aluminum content) showed the effects of shrimp farming effluents on the Hg distribution pattern. Furthermore, these results were supported by the Hg distribution in the sediment cores. This study emphasizes the necessity of including Hg as a potential pollutant when monitoring the environmental impacts of intensive shrimp farming.

  5. Subsurface-controlled geological maps for the Y-12 plant and adjacent areas of Bear Creek Valley

    SciTech Connect

    King, H.L.; Haase, C.S.

    1987-04-01

    Bear Creek Valley in the vicinity of the US Department of Energy Y-12 Plant is underlain by Middle to Late Cambrian strata of the Conasauga Group. The group consists of interbedded limestones, shales, mudstones, and siltstones, and it can be divided into six discrete formations. Bear Creek Valley is bordered on the north by Pine Ridge, which is underlain by sandstones, siltstones, and shales of the Rome Formation, and on the south by Chestnut Ridge, which is underlain by dolostones of the Knox Group. Subsurface-controlled geological maps illustrating stratigraphic data and formational contacts for the formations within the Conasauga Group have been prepared for the Y-12 Plant vicinity and selected areas in Bear Creek Valley westward from the plant. The maps are consistent with all available surface and subsurface data for areas where sufficient data exist to make map construction feasible. 13 refs.

  6. Analyzing the Modeled Tidal Signal in the Bab El Mandeb Strait and Adjacent Red Sea and Gulf of Aden Waters

    NASA Astrophysics Data System (ADS)

    Guillory, R. N. B.

    2014-12-01

    The tidal forces that dominate the Bab el Mandeb region are influenced by both the generally semi-diurnal tides in the Red Sea and mixed tides in the Gulf of Aden. Also, the tidal ranges are much greater in the Gulf of Aden (~ 2 m) than in the Red Sea (< 1m), which further complicates the tidal signal in Bab el Mandeb Strait. The Red Sea Regional Navy Coastal Model (NCOM), which includes the entire Red Sea, and the western part of the Gulf of Aden at a 1 km resolution, will be evaluated on how well it replicates the tidal signal described in literature and historical observations. In addition, the model will be compared to available temperature/salinity in situ profiles. NCOM incorporates the Oregon State University Tide Model, which should allow the ocean model to accurately reflect the transitional tides in the Bab el Mandeb Strait. Preliminary estimates indicate that the model replicates the overall circulation pattern seen in literature and the fact that there are higher tidal amplitudes in the Gulf of Aden than in the Red Sea. Approved for Public Release, Distribution Unlimited

  7. Tilted lake shorelines record the onset of motion along the Hilton Creek fault adjacent to Long Valley caldera, CA, USA

    NASA Astrophysics Data System (ADS)

    Perkins, J. P.; Finnegan, N. J.; Cervelli, P. F.; Langbein, J. O.

    2010-12-01

    Prominent normal faults occur within and around Long Valley caldera, in the eastern Sierra Nevada of California. However, their relationship to both the magmatic and tectonic evolution of the caldera since the 760 ka eruption of the Bishop Tuff remains poorly understood. In particular, in the Mono-Inyo Craters north of Long Valley, extensional faulting appears to be replaced by dike intrusion where magma is available in the crust. However, it is unclear whether extensional faults in Long Valley caldera have been active since the eruption of the Bishop Tuff (when the current topography was established) or are a relatively young phenomenon owing to the cooling and crystallization of the Long Valley magma reservoir. Here we use GPS geodesy and geomorphology to investigate the evolution of the Hilton Creek fault, the primary range-front fault bounding Long Valley caldera to the southwest. Our primary goals are to determine how long the Hilton Creek fault has been active and whether slip rates have been constant over that time interval. To characterize the modern deformation field, we capitalize on recently (July, 2010) reoccupied GPS benchmarks first established in 1999-2000. These fixed-array GPS data show no discernible evidence for recent slip on the Hilton Creek fault, which further highlights the need for longer-term constraints on fault motion. To establish a fault slip history, we rely on a suite of five prominent shorelines from Pleistocene Long Valley Lake whose ages are well constrained based on field relationships to dated lavas, and that are tilted southward toward the Hilton Creek fault. A preliminary analysis of shoreline orientations using GPS surveys and a 5-m-resolution Topographic Synthetic Aperture Radar (TOPSAR) digital elevation model shows that lake shorelines tilt towards the Hilton Creek fault at roughly parallel gradients (~ 0.6%). The measured shorelines range in inferred age from 100 ka to 500 ka, which constrain recent slip on the Hilton

  8. Continuous tidal streamflow, water level, and specific conductance data for Union Creek and the Little Back, Middle, and Front Rivers, Savannah River Estuary, November 2008 to March 2009

    USGS Publications Warehouse

    Lanier, Timothy H.; Conrads, Paul A.

    2010-01-01

    In the Water Resource Development Act of 1999, the U.S. Congress authorized the deepening of the Savannah Harbor. Additional studies were then identified by the Georgia Ports Authority and other local and regional stakeholders to determine and fully describe the potential environmental effects of deepening the channel. One need that was identified was the validation of a three-dimensional hydrodynamic model developed to evaluate mitigation scenarios for a potential harbor deepening and the effects on the Savannah River estuary. The streamflow in the estuary is very complex due to reversing tidal flows, interconnections of streams and tidal creeks, and the daily flooding and draining of the marshes. The model was calibrated using very limited streamflow data and no continuous streamflow measurements. To better characterize the streamflow dynamics and mass transport of the estuary, two index-velocity sites were instrumented with continuous acoustic velocity, water level, and specific conductance sensors on the Little Back and Middle Rivers for the 5-month period of November 2008 through March 2009. During the same period, a third acoustic velocity meter was installed on the Front River just downstream from U.S. Geological Survey streamgaging station 02198920 (Savannah River at GA 25, at Port Wentworth, Georgia) where water level and specific conductance data were being collected. A fourth index-velocity site was instrumented with continuous acoustic velocity, water level, and specific conductance sensors on Union Creek for a 2-month period starting in November 2008. In addition to monitoring the tidal cycles, streamflow measurements were made at the four index-velocity sites to develop ratings to compute continuous discharge for each site. The maximum flood (incoming) and ebb (outgoing) tides measured on Little Back River were –4,570 and 7,990 cubic feet per second, respectively. On Middle River, the maximum flood and ebb tides measured were –9,630 and 13

  9. NITROGEN CONCENTRATIONS IN LOADING SOURCES FOR THREE COASTAL LAGOONS FROM ATMOSPHERIC AND WATERSHED SOURCES, ADJACENT COASTAL MARSHES, TIDAL EXCHANGES

    EPA Science Inventory

    Abstract and Oral Presentation Gulf Estuarine Research Society.

    Standing stocks and inputs of total dissolved nitrogen (TDN) to three coastal lagoons, hereafter referred to as Kee's Bayou, Gongora, and State Park, with varying adjacent land-use, geomorphology, and water re...

  10. Sulfide variation in the pore and surface waters of artificial salt-marsh ditches and a natural tidal creek

    SciTech Connect

    Rey, J.R.; Shaffer, J.; Kain, T.; Stahl, R.; Crossman, R. )

    1992-09-01

    Pore and surface water sulfide variation near artificial ditches and a natural creek are examined in salt marshes bordering the Indian River Lagoon in east-central Florida. Pore water sulfide concentrations ranged from 0 [mu]g-at l[sup [minus]1] to 1,640 [mu]g-at l[sup [minus]1]. On average, the natural creek had the lowest sulfide concentrations (mean < 1.0 [mu]g-at l[sup [minus]1]) and the perimeter ditch of a managed salt marsh impoundment the highest (436.5 [mu]g-at l[sup [minus]1]). There was a trend of increasing sulfide concentration in the summer, and sharp peaks in late fall-early winter which correspond with peak litter input into the sediments. Significant differences in sulfide concentration between sites are attributed to differences in water flow and in organic matter content. Delaying the seasonal opening of culverts (which connect impounded marshes with the lagoon) until lagoon water levels rise in fall may prevent massive fish kills that have been associated with high sulfide levels in the impoundment perimeter ditches. 35 refs., 7 figs., 5 tabs.

  11. A Review of Tidal Salt Marsh Morphodynamics

    NASA Astrophysics Data System (ADS)

    Friedrichs, C. T.; Perry, J. E.

    2001-05-01

    We now understand that, morphologically, natural tidal marshes are generally near or progressing rapidly toward dynamic equilibrium with sediment supply, vegetative growth and relative sea level, rather than far out of equilibrium on a slow evolution toward geologic maturity. The last fifteen years have been marked by major advances in the observation of sedimentation and accretion patterns in tidal salt marshes which reinforce the above interpretation. This paper reviews and synthesizes advances since the late 1980s in our understanding of tidal salt marsh morphodynamics. Recent work has shown that allochthonous deposition patterns on the marsh are controlled primarily by source concentration, distance from that source, and duration of inundation (in turn determined by marsh elevation). Because deposition is proportional to inundation period, inorganic accretion tends to increase or decrease with accelerated or decelerated sea level rise, allowing the accretion rate to similarly fluctuate. Feedback between proximity to sediment source and duration of inundation causes relatively uniform accretion to be characterized by highest marsh elevations adjacent to tidal creeks. Since physical stress on vegetation increases with inundation, plant density and accretion of organic matter is reduced as inundation period increases, a pattern opposite to allochthonous deposition. Among systems dominated by allochthonous sediment, microtidal marshes are more reliant on storm and flood sedimentation and horizontally expand and retreat more quickly than macrotidal marshes, while the latter are more likely to persist during periods of accelerated sea level rise. The density, width and depth of salt marsh creeks all increase with increased tidal prism. Along barrier coastlines, greater tidal range is associated with more frequent inlet spacing, shallower channels, flood-dominance, and higher marsh elevation at equilibrium. Smaller tidal range results in greater inlet spacing, deeper

  12. Selenium and Other Elements in Water and Adjacent Rock and Sediment of Toll Gate Creek, Aurora, Arapahoe County, Colorado, December 2003 through March 2004

    USGS Publications Warehouse

    Herring, J.R.; Walton-Day, Katherine

    2007-01-01

    Streamwater and solid samples (rock, unconsolidated sediment, stream sediment, and efflorescent material) in the Toll Gate Creek watershed, Colorado, were collected and analyzed for major and trace elements to determine trace-element concentrations and stream loads from December 2003 through March 2004, a period of seasonally low flow. Special emphasis was given to selenium (Se) concentrations because historic Se concentrations exceeded current (2004) stream standards. The goal of the project was to assess the distribution of Se concentration and loads in Toll Gate Creek and to determine the potential for rock and unconsolidated sediment in the basin to be sources of Se to the streamwater. Streamwater samples and discharge measurements were collected during December 2003 and March 2004 along Toll Gate Creek and its two primary tributaries - West Toll Gate Creek and East Toll Gate Creek. During both sampling periods, discharge ranged from 2.5 liters per second to 138 liters per second in the watershed. Discharge was greater in March 2004 than December 2003, but both periods represent low flow in Toll Gate Creek, and results of this study should not be extended to periods of higher flow. Discharge decreased moving downstream in East Toll Gate Creek but increased moving downstream along West Toll Gate Creek and the main stem of Toll Gate Creek, indicating that these two streams gain flow from ground water. Se concentrations in streamwater samples ranged from 7 to 70 micrograms per liter, were elevated in the upstream-most samples, and were greater than the State stream standard of 4.6 micrograms per liter. Se loads ranged from 6 grams per day to 250 grams per day, decreased in a downstream direction along East Toll Gate Creek, and increased in a downstream direction along West Toll Gate Creek and Toll Gate Creek. The largest Se-load increases occurred between two sampling locations on West Toll Gate Creek during both sampling periods and between the two sampling

  13. [Spatial distribution and pollution assessment of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area, China ].

    PubMed

    Zhang, Lei; Qin, Yan-wen; Ma, Ying-qun; Zhao, Yan-min; Shi, Yao

    2014-09-01

    The aim of this article was to explore the pollution level of heavy metals in the tidal reach and its adjacent sea estuary of Daliaohe area. The contents and spatial distribution of As, Cd, Cr, Cu, Ph and Zn in surface water, suspended solids and surface sediments were analyzed respectively. The integrated pollution index and geoaccumulation index were used to evaluate the contamination degree of heavy metals in surface water and surface sediments respectively. The results indicated that the contents of heavy metals in surface water was in the order of Pb < Cu < Cd < Cr < As < Zn. The heavy metal contents in surface water increased from river to sea. Compared with the contents of heavy metals in surface water of the typical domestic estuary in China, the overall contents of heavy metals in surface water were at a higher level. The contents of heavy metals in suspended solids was in the order of Cd < Cu < As < Cr

  14. The regional structural setting of the 2008 Wells earthquake and Town Creek Flat Basin: implications for the Wells earthquake fault and adjacent structures

    USGS Publications Warehouse

    Henry, Christopher S.; Colgan, Joseph P.

    2011-01-01

    The 2008 Wells earthquake occurred on a northeast-striking, southeast-dipping fault that is clearly delineated by the aftershock swarm to a depth of 10-12 km below sea level. However, Cenozoic rocks and structures around Wells primarily record east-west extension along north- to north-northeast-striking, west-dipping normal faults that formed during the middle Miocene. These faults are responsible for the strong eastward tilt of most basins and ranges in the area, including the Town Creek Flat basin (the location of the earthquake) and the adjacent Snake Mountains and western Windermere Hills. These older west-dipping faults are locally overprinted by a younger generation of east-dipping, high-angle normal faults that formed as early as the late Miocene and have remained active into the Quaternary. The most prominent of these east-dipping faults is the set of en-échelon, north-striking faults that bounds the east sides of the Ruby Mountains, East Humboldt Range, and Clover Hill (about 5 km southwest of Wells). The northeastern-most of these faults, the Clover Hill fault, projects northward along strike toward the Snake Mountains and the approximately located surface projection of the Wells earthquake fault as defined by aftershock locations. The Clover Hill fault also projects toward a previously unrecognized, east-facing Quaternary fault scarp and line of springs that appear to mark a significant east-dipping normal fault along the western edge of Town Creek Flat. Both western and eastern projections may be northern continuations of the Clover Hill fault. The Wells earthquake occurred along this east-dipping fault system. Two possible alternatives to rupture of a northern continuation of the Clover Hill fault are that the earthquake fault (1) is antithetic to an active west-dipping fault or (2) reactivated a Mesozoic thrust fault that dips east as a result of tilting by the west-dipping faults along the west side of the Snake Mountains. Both alternatives are

  15. Effects of brush management on the hydrologic budget and water quality in and adjacent to Honey Creek State Natural Area, Comal County, Texas, 2001-10

    USGS Publications Warehouse

    Banta, J. Ryan; Slattery, Richard N.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of Agriculture Natural Resources Conservation Service, the Edwards Region Grazing Lands Conservation Initiative, the Texas State Soil and Water Conservation Board, the San Antonio River Authority, the Edwards Aquifer Authority, Texas Parks and Wildlife, the Guadalupe Blanco River Authority, and the San Antonio Water System, evaluated the hydrologic effects of ashe juniper (Juniperus ashei) removal as a brush management conservation practice in and adjacent to the Honey Creek State Natural Area in Comal County, Tex. By removing the ashe juniper and allowing native grasses to reestablish in the area as a brush management conservation practice, the hydrology in the watershed might change. Using a simplified mass balance approach of the hydrologic cycle, the incoming rainfall was distributed to surface water runoff, evapotranspiration, or groundwater recharge. After hydrologic data were collected in adjacent watersheds for 3 years, brush management occurred on the treatment watershed while the reference watershed was left in its original condition. Hydrologic data were collected for another 6 years. Hydrologic data include rainfall, streamflow, evapotranspiration, and water quality. Groundwater recharge was not directly measured but potential groundwater recharge was calculated using a simplified mass balance approach. The resulting hydrologic datasets were examined for differences between the watersheds and between pre- and post-treatment periods to assess the effects of brush management. The streamflow to rainfall relation (expressed as event unit runoff to event rainfall relation) did not change between the watersheds during pre- and post-treatment periods. The daily evapotranspiration rates at the reference watershed and treatment watershed sites exhibited a seasonal cycle during the pre- and post-treatment periods, with intra- and interannual variability. Statistical analyses indicate the mean

  16. Meiobenthic gradients with special reference to Plathelminthes and Polychaeta in an estuarine salt marsh creek—a small-scale model for boreal tidal coasts?

    NASA Astrophysics Data System (ADS)

    Hellwig-Armonies, Monika; Armonies, Werner

    1987-06-01

    Environmental conditions in salt marsh creeks are intermediate between the open tidal coast and estuaries. A large salt marsh creek at the island of Sylt (North Sea) was studied in order to test whether its fauna is more similar to that of the open tidal coast or to that of estuaries. Because of a sandy bar at the seaward opening, the tidal range is only 10 cm in the creek, and the water level never drops below the level of the sand bar. Zoobenthos in the sandy bottom and on the sandy shores was studied at both ends and in the middle of the creek. Polychaeta and Plathelminthes were determined to species level. On an average, 2115 metazoans were found below 10 cm2 of surface area. At the seaward end of the creek, abundance and taxonomic composition are similar to that of the adjoining Wadden area. Nematoda are the dominant taxon, followed by Copepoda, Plathelminthes and Oligochaeta. Taxonomic composition is different at the landward end. Plathelminthes and Nematoda are most abundant followed by Copepoda. Both Oligochaeta and Polychaeta are scarce at these newly eroded sites. Plathelminth abundance at the landward end of the creek is exceptionally high (770 935·10 cm-2). Contrary to what is generally found in estuaries, the species density of Plathelminthes shows a significant increase toward the land. The species composition of Polychaeta and Plathelminthes indicates that the sites below mean high tide level of the creek correspond to the adjacent eulittoral Wadden area while the fauna of the supralittoral sites of the creek is similar to the fauna of supralittoral tidal coasts. Typical sublittoral species did not occur in the salt marsh creek. Thus, salt marsh creeks may be regarded as a small-scale model for the tidal coast. In context with the results obtained, the definition of estuaries is discussed.

  17. Hydrogeologic and geochemical characterization of groundwater resources in Deep Creek Valley and adjacent areas, Juab and Tooele Counties, Utah, and Elko and White Pine Counties, Nevada

    USGS Publications Warehouse

    Gardner, Philip M.; Masbruch, Melissa D.

    2015-09-18

    Water-level altitude contours and groundwater ages indicate the potential for a long flow path from southwest to northeast between northern Spring and Deep Creek Valleys through Tippett Valley. Although information gathered during this study is insufficient to conclude whether or not groundwater travels along this interbasin flow path, dissolved sulfate and chloride data indicate that a small fraction of the lower altitude, northern Deep Creek Valley discharge may be sourced from these areas. Despite the uncertainty due to limited data collection points, a hydraulic connection between northern Spring Valley, Tippett Valley, and Deep Creek Valley appears likely, and potential regional effects resulting from future groundwater withdrawals in northern Spring Valley warrant ongoing monitoring of groundwater levels across this area.

  18. Design and Performance of an Enhanced Bioremediation Pilot Test in a Tidal Wetland Seep, West Branch Canal Creek, Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Majcher, Emily H.; Lorah, Michelle M.; Phelan, Daniel J.; McGinty, Angela L.

    2009-01-01

    Because of a lack of available in situ remediation methods for sensitive wetland environments where contaminated groundwater discharges, the U.S. Geological Survey, in cooperation with the U.S. Army Garrison, Aberdeen Proving Ground, Maryland, conceived, designed, and pilot tested a permeable reactive mat that can be placed horizontally at the groundwater/surface-water interface. Development of the reactive mat was part of an enhanced bioremediation study in a tidal wetland area along West Branch Canal Creek at Aberdeen Proving Ground, where localized areas of preferential discharge (seeps) transport groundwater contaminated with carbon tetrachloride, chloroform, tetrachloroethene, trichloroethene, and 1,1,2,2-tetrachloroethane from the Canal Creek aquifer to land surface. The reactive mat consisted of a mixture of commercially available organic- and nutrient-rich peat and compost that was bioaugmented with a dechlorinating microbial consortium, WBC-2, developed for this study. Due to elevated chlorinated methane concentrations in the pilot test site, a layer of zero-valent iron mixed with the peat and compost was added at the base of the reactive mat to promote simultaneous abiotic and biotic degradation. The reactive mat for the pilot test area was designed to optimize chlorinated volatile organic compound degradation efficiency without altering the geotechnical and hydraulic characteristics, or creating undesirable water quality in the surrounding wetland area, which is referred to in this report as achieving geotechnical, hydraulic, and water-quality compatibility. Optimization of degradation efficiency was achieved through the selection of a sustainable organic reactive matrix, electron donor, and bioaugmentation method. Consideration of geotechnical compatibility through design calculations of bearing capacity, settlement, and geotextile selection showed that a 2- to 3-feet tolerable thickness of the mat was possible, with 0.17 feet settlement predicted for

  19. Design and analysis of a natural-gradient ground-water tracer test in a freshwater tidal wetland, West Branch Canal Creek, Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Olsen, Lisa D.; Tenbus, Frederick J.

    2005-01-01

    A natural-gradient ground-water tracer test was designed and conducted in a tidal freshwater wetland at West Branch Canal Creek, Aberdeen Proving Ground, Maryland. The objectives of the test were to characterize solute transport at the site, obtain data to more accurately determine the ground-water velocity in the upper wetland sediments, and to compare a conservative, ionic tracer (bromide) to a volatile tracer (sulfur hexafluoride) to ascertain whether volatilization could be an important process in attenuating volatile organic compounds in the ground water. The tracer test was conducted within the upper peat unit of a layer of wetland sediments that also includes a lower clayey unit; the combined layer overlies an aquifer. The area selected for the test was thought to have an above-average rate of ground-water discharge based on ground-water head distributions and near-surface detections of volatile organic compounds measured in previous studies. Because ground-water velocities in the wetland sediments were expected to be slow compared to the underlying aquifer, the test was designed to be conducted on a small scale. Ninety-seven ?-inch-diameter inverted-screen stainless-steel piezometers were installed in a cylindrical array within approximately 25 cubic feet (2.3 cubic meters) of wetland sediments, in an area with a vertically upward hydraulic gradient. Fluorescein dye was used to qualitatively evaluate the hydrologic integrity of the tracer array before the start of the tracer test, including verifying the absence of hydraulic short-circuiting due to nonnatural vertical conduits potentially created during piezometer installation. Bromide and sulfur hexafluoride tracers (0.139 liter of solution containing 100,000 milligrams per liter of bromide ion and 23.3 milligrams per liter of sulfur hexafluoride) were co-injected and monitored to generate a dataset that could be used to evaluate solute transport in three dimensions. Piezometers were sampled 2 to 15 times

  20. Geology of Cedar Creek anticline in Baker, Wibaux, and Glendive 30 x 60-min quadrangles, eastern Montana and adjacent North Dakota

    SciTech Connect

    Vuke-Foster, S.M.

    1986-08-01

    Geology of the asymmetrical, northwest-trending Cedar Creek anticline, a major oil- and gas-producing structure of the Williston basin, was mapped in the Wibaux and Glendive Quadrangles as part of the USGS-funded Coal Lands Mapping Program. Thinning of stratigraphic units, unconformities, and relationships between tectonic structures provide suggestive evidence for the timing of Late Cretaceous and Tertiary uplift in this area. The Colgate Member of the Fox Hills Formation (Maestrichtian) pinches out toward the axis of the anticline. The contact between the Hell Creek Formation (Maestrichtian) and the underlying Colgate Member is disconformable near the axis of the anticline and becomes conformable about 8 km (5 mi) east of it. This suggests Late Cretaceous uplift during or after deposition of the Colgate Member. The Hell Creek Formation also thins by up to 40 m (131.2 ft) toward the axis. Part of the Fort Union Formation is not present on the eastern limb of the anticline and in an area southwest of the anticline, suggesting that these areas were uplifted at the time of or just following deposition of this part of the section during the middle Paleocene. The present anticline developed following deposition of the Fort Union Formation in the late Paleocene. Several associated faults and folds developed subparallel to the axial trend, including a pronounced synclinal flexure along much of the western limb of the anticline. Subsequently, northeast-trending faults with a component of right-lateral slip offset the northwest-trending linear features associated with the anticline.

  1. Water-surface profile and flood boundaries for the computed 100-year flood, Big Muddy Creek, Fort Peck Indian Reservation and adjacent area, Montana

    USGS Publications Warehouse

    Omang, R.J.

    1996-01-01

    Hydrologic and hydraulic evaluations of Big Muddy Creek were made to determine the magnitude of the 100-year flood and the extent of flooding that would occur as the result of this flood. The magnitude of the 100-year flood was determined to range from 13,600 to 20,400 ft3/s, depending on location. Field surveys were made at 39 cross sections along a 41-mile reach of Big Muddy Creek. An additional two cross sections along the same reach were synthesized. Data from the surveys were used to calculate the water-surface elevation at each cross section using a computer program (WSPRO) developed by the U.S. Geological Survey. The water-surface profile of the computed 100-year flood elevations was then drawn. The profile also shows the streambed elevation and the location of the bridges and cross sections. The computed 100-year flood elevation at each cross section was used to delineate the width of the flood plain at that section. Flood boundaries between cross sections were interpolated using contour lines on topographic maps.

  2. 1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE ...

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

    1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE OF THE ADIT OPENINGS (VIEW TO THE NORTH). - Foster Gulch Mine, Fan Housing, Bear Creek 1 mile Southwest of Town of Bear Creek, Red Lodge, Carbon County, MT

  3. Effects of brush management on the hydrologic budget and water quality in and adjacent to Honey Creek State Natural Area, Comal County, Texas, 2001--10

    USGS Publications Warehouse

    Banta, J. Ryan; Slattery, Richard N.

    2012-01-01

    Woody vegetation, including ashe juniper (Juniperus ashei), has encroached on some areas in central Texas that were historically oak grassland savannah. Encroachment of woody vegetation is generally attributed to overgrazing and fire suppression. Removing the ashe juniper and allowing native grasses to reestablish in the area as a brush management conservation practice (hereinafter referred to as "brush management") might change the hydrology in the watershed. These hydrologic changes might include changes to surface-water runoff, evapotranspiration, or groundwater recharge. The U.S. Geological Survey (USGS), in cooperation with Federal, State, and local partners, examined the hydrologic effects of brush management in two adjacent watersheds in Comal County, Tex. Hydrologic data were collected in the watersheds for 3-4 years (pre-treatment) depending on the type of data, after which brush management occurred on one watershed (treatment watershed) and the other was left in its original condition (reference watershed). Hydrologic data were collected in the study area for another 6 years (post-treatment). These hydrologic data included rainfall, streamflow, evapotranspiration, and water quality. Groundwater recharge was not directly measured, but potential groundwater recharge was calculated by using a simplified mass balance approach. This fact sheet summarizes highlights of the study from the USGS Scientific Investigations Report on which it is based.

  4. Assessment of volatile organic compounds in surface water at Canal Creek, Aberdeen Proving Ground, Maryland, November 1999-September 2000

    USGS Publications Warehouse

    Phelan, Daniel J.; Olsen, Lisa D.; Senus, Michael P.; Spencer, Tracey A.

    2001-01-01

    The purpose of this report is to describe the occurrence and distribution of volatile organic compounds in surface-water samples collected by the U.S. Geological Survey in the Canal Creek area of Aberdeen Proving Ground, Maryland, from November 1999 through September 2000. The report describes the differences between years with below normal and normal precipitation, the effects of seasons, tide stages, and location on volatile organic compound concentrations in surface water, and provides estimates of volatile organic concentration loads to the tidal Gunpowder River. Eighty-four environmental samples from 20 surface-water sites were analyzed. As many as 13 different volatile organic compounds were detected in the samples. Concentrations of volatile organic compounds in surface-water samples ranged from below the reporting limit of 0.5 micrograms per liter to a maximum of 50.2 micrograms per liter for chloroform. Chloroform was detected most frequently, and was found in 55 percent of the environmental samples that were analyzed for volatile organic compounds (46 of 84 samples). Carbon tetrachloride was detected in 56 percent of the surface-water samples in the tidal part of the creek (34 of 61 samples), but was only detected in 3 of 23 samples in the nontidal part of the creek. 1,1,2,2-Tetrachloroethane was detected in 43 percent of the tidal samples (26 of 61 samples), but was detected at only two nontidal sites and only during November 1999. Three samples were collected from the tidal Gunpowder River about 300 feet from the mouth of Canal Creek in May 2000, and none of the samples contained volatile organic compound concentrations above detection levels. Volatile organic compound concentrations in surface water were highest in the reaches of the creek adjacent to the areas with the highest known levels of ground-water contamination. The load of total volatile organic compounds from Canal Creek to the Gunpowder River is approximately 1.85 pounds per day (0

  5. Water-quality and water-level data for a freshwater tidal wetland, West Branch Canal Creek, Aberdeen Proving Ground, Maryland, October 1998-September 1999

    USGS Publications Warehouse

    Spencer, Tracey A.; Olsen, Lisa D.; Lorah, Michelle M.; Mount, Mastin M.

    2000-01-01

    This report presents water-quality data for ground-water and surface-water samples and water-level data collected by the U.S. Geological Survey from October 1998 through September 1999 at West Branch Canal Creek, Aberdeen Proving Ground, Maryland. The report also provides a description of the sampling and analytical methods that were used to collect and analyze the samples, and includes an evaluation of the quality-assurance data. The ground-water sampling network includes 88 wells or piezometers, including four 2-inch wells, two 4-inch wells, thirty 0.75-inch piezo-meters, and fifty-two 0.25-inch piezometers. Water levels were measured in 105 wells or piezometers. Surface-water samples were collected at five sites. Samples were collected from wells and 0.75-inch piezometers for measurement of field parameters, and analysis of inorganic and organic constituents during three sampling rounds: March, May through June, and July through August of 1999. Inorganic constituents and organic constituents were analyzed in samples collected from 0.25-inch piezometers during three sampling rounds in February through March, May, and September of 1999. Water levels were measured in October and November of 1998, and in February and May of 1999. Surface-water samples were collected between February and August of 1999 for analysis of organic constituents.

  6. Natural and anthropogenic change in the morphology and connectivity of tidal channels of southwest Bangladesh

    NASA Astrophysics Data System (ADS)

    Wilson, C.; Goodbred, S. L., Jr.; Wallace Auerbach, L.; Ahmed, K. R.; Small, C.; Sams, S. E.

    2014-12-01

    Over the last century, land use changes in the Ganges-Brahmaputra tidal delta have transformed >5000 km2 of intertidal mangrove forest to densely inhabited, agricultural islands that have been embanked to protect against tides and storm surges (i.e., polders). More recently, the conversion of rice paddies to profitable shrimp aquaculture has become increasingly widespread. Recent field studies documented that poldering in southwest Bangladesh has resulted in an elevation deficit relative to that of the natural mangrove forests and mean high water (MHW). The offset is a function of lost sedimentation, enhanced compaction, and an effective rise in MHW from tidal amplification. The morphologic adjustment of the tidal channel network to these perturbations, however, has gone largely undocumented. One effect has been the shoaling of many channels due to decreases in fluvial discharge and tidal prism. We document a previously unrecognized anthropogenic component: the widespread closure of large conduit tidal channels for land reclamation and shrimp farming. GIS analysis of historical Landsat and Google Earth imagery within six 1000 km2 study areas reveals that the tidal network in the natural Sundarbans mangrove forest has remained relatively constant since the 1970s, while significant changes are observed in human-modified areas. Construction of the original embankments removed >1000 km of primary tidal creeks, and >80 km2 of land has been reclaimed outside of polders through the closure of formerly active tidal channels (decrease in mean channel width from 256±91 m to 25±10 m). Tidal restriction by large sluice gates is prevalent, favoring local channel siltation. Furthermore, severing the intertidal platform and large conduit channels from the tidal network has had serious repercussions, such as increased lateral migration and straightening of the remaining channels. Where banklines have eroded, the adjacent embankments appear to be more vulnerable to failure, as

  7. The mangrove pump: The tidal flushing of animal burrows in a tropical mangrove forest determined from radionuclide budgets

    NASA Astrophysics Data System (ADS)

    Stieglitz, Thomas C.; Clark, Jordan F.; Hancock, Gary J.

    2013-02-01

    Intertidal mangrove forests contribute significantly to biogeochemical solute budgets of tropical and subtropical coastlines. A significant part of the biogeochemical cycling in mangrove ecosystems occurs within the subsurface of the forest floor. This subsurface source and the 'offshore' sink are linked by the tidally-driven movement of water through the mangrove forest floor. The tidal circulation through animal macro-burrows in the Coral Creek mangrove forest (area 3 km2) on Hinchinbrook Island (Australia) is documented by constructing mass balances of isotopes of radium and radon measured in the creek in 1997 and 2005 respectively. Isotope activities in burrows were found to be significantly greater than in the adjacent mangrove creek (e.g. for 222Rn, 680-1750 and 30-170 Bq m-3 in burrows and creek respectively). From isotope mass balances, a daily water circulation flux through burrows of 30.4 ± 4.7 L m-2 of forest floor is calculated. This study quantifies the underlying physical process, i.e. the tidal flushing of burrows, that supports significant and continuous exports of soluble organic and inorganic matter from mangrove forest floors to the coastal ocean. The potential significance of the circulation flux estimate is illustrated by up-scaling of the forest-scale estimates to the mangrove forests in the entire central Great Barrier Reef. This extrapolation indicates that the annual water flux circulated by this tidally-driven 'mangrove pump' is equivalent to as much as 20% (16-22%) of the total annual river discharge along the ca. 400 km long coastline of this region.

  8. View of viaduct, looking SE from roof of adjacent parking ...

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

    View of viaduct, looking SE from roof of adjacent parking garage. - Mulberry Street Viaduct, Spanning Paxton Creek & Cameron Street (State Route 230) at Mulberry Street (State Route 3012), Harrisburg, Dauphin County, PA

  9. 10. Detail and contextual view of bridge and adjacent farmstead ...

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

    10. Detail and contextual view of bridge and adjacent farmstead setting. Note laced vertical compression members, latticed portal strut, decorative strut bracing, and lightness of diagonal and lateral tension members. View to southeast through southeast portal from truss mid-span. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

  10. Tidal Energy.

    ERIC Educational Resources Information Center

    Impact of Science on Society, 1987

    1987-01-01

    States that tidal power projects are feasible in a relatively limited number of locations around the world. Claims that together they could theoretically produce the energy equivalent to more than one million barrels of oil per year. (TW)

  11. Quantifying vegetation and nekton response to tidal restoration of a New England salt marsh

    USGS Publications Warehouse

    Roman, C.T.; Raposa, K.B.; Adamowicz, S.C.; James-Pirri, M.J.; Catena, J.G.

    2002-01-01

    Tidal flow to salt marshes throughout the northeastern United States is often restricted by roads, dikes, impoundments, and inadequately sized culverts or bridge openings, resulting in altered ecological structure and function. In this study we evaluated the response of vegetation and nekton (fishes and decapod crustaceans) to restoration of full tidal flow to a portion of the Sachuest Point salt marsh, Middletown, Rhode Island. A before, after, control, impact study design was used, including evaluations of the tide-restricted marsh, the same marsh after reintroduction of tidal flow (i.e., tide-restored marsh), and an unrestricted control marsh. Before tidal restoration vegetation of the 3.7-ha tide-restricted marsh was dominated by Phragmites australis and was significantly different from the adjacent 6.3-ha Spartina -dominated unrestricted control marsh (analysis of similarities randomization test, p < 0.001). After one growing season vegetation of the tide-restored marsh had changed from its pre-restoration condition (analysis of similarities randomization test, p < 0.005). Although not similar to the unrestricted control marsh, Spartina patens and S. alterniflora abundance increased and abundance and height of Phragmites significantly declined, suggesting a convergence toward typical New England salt marsh vegetation. Before restoration shallow water habitat (creeks and pools) of the unrestricted control marsh supported a greater density of nekton compared with the tide-restricted marsh (analysis of variance, p < 0.001), but after one season of restored tidal flow nekton density was equivalent. A similar trend was documented for nekton species richness. Nekton density and species richness from marsh surface samples were similar between the tide-restored marsh and unrestricted control marsh. Fundulus heteroclitus and Palaemonetes pugio were the numerically dominant fish and decapod species in all sampled habitats. This study provides an example of a

  12. Are historical pollution events on the Delaware River recorded as geochemical marker horizons in adjacent marsh sediments

    SciTech Connect

    Walsh, R.; Yemane, K. . Dept. of Geology Bryn Mawr Coll., PA . Geology Dept.)

    1993-03-01

    In the last two hundred years of massive population and industrial growth, the Delaware River has been subjected to several minor and major pollutions. For example, as recently as June 1989 the tanker Presidente Rivera spilled an estimated hundred thousand to million gallons of oil into the river. In the Lower Delaware Basin tides affect the river and its tributaries up to a hundred kilometers inland. The freshwater marshes adjacent to the creeks that empty into the Delaware River experience diurnal tidal sedimentation. It is thus expected that the pollutants in the waterway would be transported via the tidal channels into the adjacent wetlands. The high sedimentation rate, clay-rich sediments, accumulation of terrestrial organic matter, and the low energy environments in these marshes should ensure rapid burial which may preserve some of the contaminants transported into the marshes. To test this hypothesis the authors selected a freshwater marsh along the Raccoon Creek just south of Philadelphia in New Jersey, and collected a 2 m core from a relatively undisturbed portion of the marsh, about 15 m away from the tidal channels. The pH averages around 6.2, ranges from 5.5--6.8, but, is slightly higher in the middle part of the core. The bulk mineralogy comprises chlorite, illite, kaolinite, feldspars and quartz. Vivianite and vermiculite were observed at places lower in the core. Graminae dominates the pollen/spore taxa. The organic debris is unaltered throughout the core. The authors will measure heavy metals and toxic chemicals on < 2[mu]m clay fractions. Also pristane/phytane ratios, indicative of hydrocarbons (crude oils), will be determined on organic matter extracts. The authors will compare and correlate the results to historically documented events of chemical and petroleum spills on the Delaware River.

  13. Final report (2002-2004): Benthic macroinvertebrate communities of reconstructed freshwater tidal wetlands in the Anacostia River, Washington, D.C

    USGS Publications Warehouse

    Brittingham, K.D.; Hammerschlag, R.S.

    2006-01-01

    Considerable work has been conducted on the benthic communities of inland aquatic systems, but there remains a paucity of effort on freshwater tidal wetlands. This study characterized the benthic macroinvertebrate communities of recently reconstructed urban freshwater tidal wetlands along the Anacostia River in Washington, D.C. The focus of the study was on the two main areas of Kingman Marsh, which were reconstructed by the U.S. Army Corps of Engineers in 2000 using Anacostia dredge material. Populations from this 'new' marsh were compared to those of similarly reconstructed Kenilworth Marsh (1993) just one half mile upstream, the relic reference Dueling Creek Marsh in the upper Anacostia estuary and the outside reference Patuxent freshwater tidal marsh in an adjacent watershed. Benthic macro invertebrate organisms were collected using selected techniques for evaluation including the Ekman bottom grab sampler, sediment corer, D-net and Hester-Dendy sampler. Samples were collected at least seasonally from tidal channels, tidal mudflats, three vegetation/sediment zones (low, middle and high marsh), and pools over a 3-year period (late 2001-2004). The macroinvertebrate communities present at the marsh sites proved to be good indicators of disturbance and stress (Kingman Marsh), pollution, urban vs. rural location (Kenilworth and Patuxent), and similarities between reconstructed and remnant wetlands (Kenilworth and Dueling Creek). Macroinvertebrate density was significantly greater at Kingman Marsh than Kenilworth Marsh due to more numerous chironomids and oligochaetes. This may reflect an increase in unvegetated sediments at Kingman (even at elevations above natural mudflat) due to grazing pressure from over-abundant resident Canada geese. Unvegetated sediments yielded greater macroinvertebrate abundance but lower richness than vegetated marsh sites. Data collected from this study provides information on the extent that benthic macroinvertebrate communities can serve

  14. Tidal Meanders

    NASA Astrophysics Data System (ADS)

    Marani, M.; Lanzoni, S.; Zandolin, D.; Seminara, S.; Rinaldo, A.

    Observational evidence is presented on the geometry of meandering tidal channels evolved within coastal wetlands characterized by different tidal, hydrodynamic, to- pographic, vegetational and ecological features. New insight is provided on the ge- ometrical properties of tidal meanders, with possible dynamic implications on their evolution. In particular, it is shown that large spatial gradients of leading flow rates induce important spatial variabilities of meander wavelengths and widths, while their ratio remains remarkably constant in the range of scales of observation. This holds regardless of changes in width and wavelength up to two orders of magnitude. This suggests a locally adapted evolution, involving the morphological adjustment to the chief landforming events driven by local hydrodynamics. The spectral analysis of lo- cal curvatures reveals that Kinoshita's model curve does not fit tidal meanders due to the presence of even harmonics, in particular the second mode. Geometric parameters are constructed that are suitable to detect possible geomorphic signatures of the tran- sitions from ebb- to flood-dominated hydrodynamics, here related to the skewness of the tidal meander. Trends in skewness, however, prove elusive to measure and fail to show detectable patterns. We also study comparatively the spatial patterns of evolu- tion of the ratios of channel width to depth, and the ratio of width to local radius of curvature. Interestingly, the latter ratio exhibits consistency despite sharp differences in channel incision. Since the degree of incision, epitomized by the width-to-depth ratio, responds to the relevant erosion and migrations mechanisms and is much sen- sitive to vegetation and sediment properties, it is noticeable that we observe a great variety of landscape carving modes and yet recurrent planar features like constant width/curvature and wavelength/width ratios.

  15. 3. NORTHEASTERN VIEW OF THE ROCK CREEK AND POTOMAC PARKWAY ...

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

    3. NORTHEASTERN VIEW OF THE ROCK CREEK AND POTOMAC PARKWAY RAMP. VIEW TAKEN FROM NORTHERN RAILING OF MEMORIAL BRIDGE. - Arlington Memorial Bridge, Watergate & Bridge Plaza, Adjacent to Arlington Memorial Bridge & Lincoln Memorial, Washington, District of Columbia, DC

  16. Electrical Resistivity Imaging of Tidal Fluctuations in the Water Table at Inwood Hill Park, Manhattan

    NASA Astrophysics Data System (ADS)

    Kenyon, P. M.; Kassem, D.; Olin, A.; Nunez, J.; Smalling, A.

    2005-05-01

    Inwood Hill Park is located on the northern tip of Manhattan and has been extensively modified over the years by human activities. In its current form, it has a backbone of exposed or lightly covered bedrock along the Hudson River, adjacent to a flat area with two tidal inlets along the northern shore of Manhattan. The tidal motions in the inlets are expected to drive corresponding fluctuations in the water table along the borders of the inlets. In the Fall of 2002, a group of students from the Department of Earth and Atmospheric Sciences at the City College of New York studied these fluctuations. Electrical resistivity cross sections were obtained with a Syscal Kid Switch 24 resistivity meter during the course of a tidal cycle at three locations surrounding the westernmost inlet in the park. No change was seen over a tidal cycle at Site 1, possibly due to the effect of concrete erosion barriers which were located between the land and the water surrounding this site. Measurements at Site 2 revealed a small, regular change in the water table elevation of approximately 5 cm over the course of a tidal cycle. This site is inferred to rest on alluvial sediments deposited by a small creek. The cross sections taken at different times during a tidal cycle at Site 3 were the most interesting. They show a very heterogeneous subsurface, with water spurting between blocks of high resistivity materials during the rising portion of the cycle. A small sinkhole was observed on the surface of the ground directly above an obvious plume of water in the cross section. Park personnel confirmed that this sinkhole, like others scattered around this site, is natural and not due to recent construction activity. They also indicated that debris from the construction of the New York City subways may have been dumped in the area in the past. Our conclusion is that the tidal fluctuations at Site 3 are being channeled by solid blocks in the construction debris, and that the sinkholes currently

  17. Estimating tidal current amplitudes outside estuaries and characterizing the zone of estuarine tidal influence

    NASA Astrophysics Data System (ADS)

    Whitney, Michael M.; Garvine, Richard W.

    2008-02-01

    Tidal currents within many estuaries are stronger than on the adjacent continental shelf. Estuarine tidal influence extends onto the shelf elevating tidal amplitudes above ambient shelf levels over a region outside the estuary. In this paper, a kinematic theory that describes tidal flow in these estuary-shelf tidal interaction zones is derived and tested. Using these results, tidal current amplitudes outside estuaries are estimated and the range and intensity of estuarine tidal influence is characterized. The estimates for the tidal current amplitudes ( utide) of the dominant constituent are appropriate for linear or weakly nonlinear systems with predominantly barotropic tides; the ratio of tidal height to water depth is small ( η/ h≪1) in linear or weakly nonlinear regimes. Within tidal interaction zones, the tidal current amplitude is composed of an ambient shelf part ( ua) and an estuary-induced part ( ue). The characteristic shelf amplitude far from the estuary is used to set ua. Continuity arguments indicate that ue (averaged over a control volume arc centered on the mouth with radius r and a swath angle of γπ) approximately equals the ratio of the tidal volume flux through the mouth ( Vm) and the cross-sectional area of any control volume arc (u≈V/γπrh¯). This approximation holds where the squared product of the tidal wave number and radial distance is small: ( kr) 2≪1. For a shelf with constant slope α and small coastal wall depth, the arc-averaged depth is h¯≈sr (where s=2 α/ pi for γ=1). For this shelf bathymetry, ue decays with squared radial distance from the estuary mouth. Theoretical predictions are consistent with observed tidal current amplitudes outside the Delaware Bay and Block Island Sound. In both test cases, the estimated and observed amplitudes exhibit an r-2 dependence and decay over a similar distance. The relative importance of estuarine tidal influence is assessed with the tidal interaction index ( Ti= ue/ ua). The

  18. Seasonal Variation in the Quality of Dissolved and Particulate Organic Matter Exchanged Between a Salt Marsh and Its Adjacent Estuary

    NASA Astrophysics Data System (ADS)

    Osburn, C. L.; Mikan, M.; Etheridge, J. R.; Burchell, M. R.; Birgand, F.

    2015-12-01

    Salt marshes are transitional ecosystems between terrestrial and marine environments. Along with mangroves and other vegetated coastal habitats, salt marshes rank among the most productive ecosystems on Earth, with critical global importance for the planet's carbon cycle. Fluorescence was used to examine the quality of dissolved and particulate organic matter (DOM and POM) exchanging between a tidal creek in a created salt marsh and its adjacent estuary in eastern North Carolina, USA. Samples from the creek were collected hourly over four tidal cycles in May, July, August, and October of 2011. Absorbance and fluorescence of chromophoric DOM (CDOM) and of base-extracted POM (BEPOM) served as the tracers for organic matter quality while dissolved organic carbon (DOC) and base-extracted particulate organic carbon (BEPOC) were used to compute fluxes. Fluorescence was modeled using parallel factor analysis (PARAFAC) and principle components analysis (PCA) of the PARAFAC results. Of nine PARAFAC components modeled, we used multiple linear regression to identify tracers for recalcitrant DOM; labile soil-derived source DOM; detrital POM; and planktonic POM. Based on mass balance, recalcitrant DOC export was 86 g C m-2 yr-1 and labile DOC export was 49 g C m-2 yr-1. The marsh also exported 41 g C m-2 yr-1 of detrital terrestrial POC, which likely originated from lands adjacent to the North River estuary. Planktonic POC export from the marsh was 6 g C m-2 yr-1. Using the DOM and POM quality results obtained via fluorescence measurements and scaling up to global salt marsh area, we estimated that the potential release of CO2 from the respiration of salt marsh DOC and POC transported to estuaries could be 11 Tg C yr-1, roughly 4% of the recently estimated CO2 release for marshes and estuaries globally.

  19. Depositional environment and geochemical response of mangrove sediments from creeks of northern Maharashtra coast, India.

    PubMed

    Volvoikar, Samida P; Nayak, G N

    2013-04-15

    Present study provides results of trace metal distribution in mangrove sediment cores collected from macro-tidal Khonda and Dudh creeks of Northern Maharashtra coast, India. Most of the metals showed significant higher addition in Dudh creek (core DC) as compared to Khonda creek (core KC). However, Khonda creek sediments did show anthropogenic enrichment of Mn, Zn and Ni, while Dudh creek sediments showed anthropogenic enrichment of almost all the studied metals. Large difference in metal concentration between the two creeks was attributed to their proximity to industries. The higher Mn, Zn and Ni content in Khonda creek was mainly attributed to addition from domestic and agricultural wastes. While high deterioration of Dudh creek sediments was the outcome of addition from industrial effluents.

  20. Benthic macroinvertebrate richness along Sausal Creek, Oakland, California

    NASA Astrophysics Data System (ADS)

    Lara, D.; Ahumada, E.; Leon, Y.; Bracho, H.; Telles, C.

    2012-12-01

    Sausal Creek, 5.0 km long, is one of the principal watercourses in Oakland, California. The headwaters of Sausal Creek arise in the Oakland Hills and the creek flows southwestward through the city, discharging into the tidal canal that separates the island of Alameda from Oakland; the creek ultimately flows into San Francisco Bay. Due to the presence of rainbow trout, the stream health of Sausal Creek is a local conservation priority. In the present study, a survey of benthic macroinvertebrates in the creek was conducted and possible correlations between environmental variables and taxonomic richness were analyzed. Three stations along the creek were sampled using a 30.5cm 500 micron aquatic d-net, and temperature, pH and dissolved oxygen levels were measured in creek samples obtained at each station. Temperature, pH and dissolved oxygen levels remained constant along the creek. Taxonomic richness was highest at the upstream site of Palo Seco, located in an eastern section of the creek, and furthest downstream at Dimond Park, in the western portion of the creek. The Monterrey site, just west of Palo Seco was found to be significantly low in benthic macroinvertebrates. The Palo Seco and Monterrey sites are separated by Highway 13 and storm drain inputs may bring contaminants into the creek at this site. At the Monterrey site Sausal Creek follows the Hayward Fault, gas emissions or change in substrate may also affect the local population of benthic invertebrates. Further research will be conducted to determine what factors are contributing to this local anomaly.

  1. The impact of organic pollution on the macrobenthic fauna of Dubai Creek (UAE).

    PubMed

    Saunders, James E; Al Zahed, Khalid Mohammed; Paterson, David M

    2007-11-01

    Dubai Creek is a tidal marine intrusion bisecting Dubai within the United Arab Emirates (UAE). The creek extends 14km inland from its opening into the Arabian Gulf, with a narrow lower creek channel leading to a lagoon section in the upper creek. The creek contains numerous sources of organic pollution including sewage outlet flows and boat waste. A survey of the creek was performed, assessing organic pollution, water properties, and the benthic macrofaunal community. The upper creek was heavily polluted with macrofauna communities commonly associated with organic pollution and eutrophication, while the lower creek contained low pollution and relatively healthy macrofauna communities. There is little net tidal flow of water within the creek and residence time in the lagoon is high, which may account for the high organic pollution levels. However, some evidence of the pollution effect moving into the lower creek was found. The results are considered in light of current and historic organic loading within the creek and future developments in the area.

  2. Geologic map of the Skull Creek Quadrangle, Moffat County Colorado

    USGS Publications Warehouse

    Van Loenen, R. E.; Selner, Gary; Bryant, W.A.

    1999-01-01

    The Skull Creek quadrangle is in northwestern Colorado a few miles north of Rangely. The prominent structural feature of the Skull Creek quadrangle is the Skull Creek monocline. Pennsylvanian rocks are exposed along the axis of the monocline while hogbacks along its southern flank expose rocks that are from Permian to Upper Cretaceous in age. The Wolf Creek monocline and the Wolf Creek thrust fault, which dissects the monocline, are salient structural features in the northern part of the quadrangle. Little or no mineral potential exists within the quadrangle. A geologic map of the Lazy Y Point quadrangle, which is adjacent to the Skull Creek quadrangle on the west, is also available (Geologic Investigations Series I-2646). This companian map shows similar geologic features, including the western half of the Skull Creek monocline. The geology of this quadrangle was mapped because of its proximity to Dinosaur National Monument. It is adjacent to quadrangles previously mapped to display the geology of this very scenic and popular National Monument. The Skull Creek quadrangle includes parts of the Skull Creek Wilderness Study Area, which was assessed for its mineral resource potential.

  3. Hydrodynamic and geomorphological controls on suspended sediment transport in mangrove creek systems, a case study: Cocoa Creek, Townsville, Australia

    NASA Astrophysics Data System (ADS)

    Bryce, S.; Larcombe, P.; Ridd, P. V.

    2003-03-01

    In tide-dominated sedimentary systems, close relationships exist between tidal hydrodynamics, sediment transport and geomorphology. Tropical coastlines contain many tide-dominated mangrove creeks, yet few studies to date have examined the detail of such relationships for these environments. Time-series observations of tidal height, currents and suspended sediment concentrations were taken between 1992 and 1996 in Cocoa Creek, a mangrove creek system near Townsville, NE Australia. The creek and surrounding mangrove swamps and salt flats were surveyed with an echo-sounder and total survey station, respectively. For 'within-channel' tides, the flood tide is always the fastest, at up to 0.5 m s -1. In contrast, for overbank tides (i.e. tidal height > + 1.5 m Australian Height Datum, AHD) ebb currents are fastest in July, December and January, but flood currents are fastest in August and September, at up to 1 m s -1 in both cases. The tidal asymmetry of overbank tides in Cocoa Creek is controlled by the interaction between offshore tidal forcing and the intertidal storage effect of the mangrove swamps and salt flats, with the result being that during certain periods of the year there tends to be a predominance of either faster flood or ebb velocities on overbank tides. Significant tidal suspended sediment transport in the channel is only initiated at overbank height. On overbank tides, measured net suspended sediment fluxes in the channel are mostly seaward-directed (up to 180 t per tidal cycle). However, the net flux measured over a neap-spring period may be either landwards or seawards (up to 465 and 60 t, respectively). Furthermore, on the larger overbank tides (where the maximum tidal height >+1.85 m AHD) net sediment fluxes may be reduced because of a limited supply of available material. Thus hydrodynamic and sediment sampling durations of up to a month may not be representative of long-term trends. Given that our large dataset has not identified a clear long

  4. 1. EAGLE CREEK RECREATION AREA, VIEW OF EAGLE CREEK TRAIL ...

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

    1. EAGLE CREEK RECREATION AREA, VIEW OF EAGLE CREEK TRAIL REGISTRY BOOTH. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  5. Hydrodynamics and sediment suspension in shallow tidal channels intersecting a tidal flat

    NASA Astrophysics Data System (ADS)

    Pieterse, Aline; Puleo, Jack A.; McKenna, Thomas E.

    2016-05-01

    A field study was conducted on a tidal flat intersected by small tidal channels (depth <0.1 m, width <2 m) within a tidal marsh. Data were collected in the channels, and on the adjacent tidal flat that encompasses approximately 1600 m2 in planform area. Hydrodynamic processes and sediment suspension between the channels and adjacent flat were compared. Shear stress and turbulent kinetic energy were computed from high frequency velocity measurements. Maximum water depth at the field site varied from 0.11 m during the lowest neap high tide to 0.58 m during a storm event. In the channel intersecting the tidal flat, the shear stress, turbulence and along-channel velocity were ebb dominant; e.g. 0.33 m/s peak velocity for ebb compared to 0.19 m/s peak velocity for flood. Distinct pulses in velocity occurred when the water level was near the tidal flat level. The velocity pulse during flood tide occurred at a higher water level than during ebb tide. No corresponding velocity pulse on the tidal flat was observed. Sediment concentrations peaked at the beginning and end of each tidal cycle, and often had a secondary peak close to high tide, assumed to be related to sediment advection. The influence of wind waves on bed shear stress and sediment suspension was negligible. Water levels were elevated during a storm event such that the tidal flat remained inundated for 4 tidal cycles. The water did not drain from the tidal flat into the channels during the storm, and no velocity pulses occurred. Along-channel velocities, turbulent kinetic energy, and shear stresses were therefore smaller in the channels during storm conditions than during non-storm conditions.

  6. Suspended Solids Flux Between Salt Marsh and Adjacent Bay: A Long-term Continuous Measurement

    NASA Astrophysics Data System (ADS)

    Suk, N. S.; Guo, Q.; Psuty, N. P.

    1999-07-01

    The beneficial roles of coastal salt marshes have been well identified as a storm surge protector, a nursery for young fish and a natural filter for pollutants. However, the vectors of nutrients and suspended solids exchanges between the salt marsh and the adjacent bay are not completely known. In this study, suspended solids flux between a salt marsh at Tuckerton, New Jersey, U.S.A. and Great Bay was continuously measured for an extended period of time by an improved monitoring methodology. A field infrared nephelometric turbidimeter was deployed to measure turbidity continuously at the mouth of the tidal creek, and the measured turbidity data were used to derive suspended solids concentrations. Current velocity and water surface elevation were measured concurrently at the same location. During the monitoring period from March to October 1996, suspended solids were found to be imported into the salt marsh from the adjacent bay. The small net import appeared to be inadequate for wetlands areal viability when compared to the relative sea-level rise rates. Results of this study suggested that a minimum of five water sample sets were needed to establish a reasonably good overall TSS-turbidity regression relationship in terms of flux quantification.

  7. KANAB CREEK ROADLESS AREA, ARIZONA.

    USGS Publications Warehouse

    Billingsley, George H.; Ellis, Clarence E.

    1984-01-01

    On the basis of a mineral survey, the Kanab Creek Roadless Area in north-central Arizona has a probable mineral-resource potential for uranium and copper in four small areas around five collapse structures. Gypsum is abundant in layers along the canyon rim of Snake Gulch, but it is a fairly common mineral in the region outside the roadless area. There is little promise for the occurence of fossil fuels in the area. Studies of collapse structures in surrounding adjacent areas might reveal significant mineralization at depth, such as the recent discovery of the uranium ore body at depth in the Pigeon Pipe.

  8. Tidal stress triggering of earthquakes in Southern California

    NASA Astrophysics Data System (ADS)

    Bucholc, Magda; Steacy, Sandy

    2016-05-01

    We analyse the influence of the solid Earth tides and ocean loading on the occurrence time of Southern California earthquakes. For each earthquake, we calculate tidal Coulomb failure stress and stress rate on a fault plane that is assumed to be controlled by the orientation of the adjacent fault. To reduce bias when selecting data for testing the tide-earthquake relationship, we create four earthquake catalogues containing events within 1, 1.5, 2.5 and 5 km of nearest faults. We investigate the difference in seismicity rates at times of positive and negative tidal stresses/stress rates given three different cases. We consider seismicity rates during times of positive versus negative stress and stress rate, as well as 2 and 3 hr surrounding the local tidal stress extremes. We find that tidal influence on earthquake occurrence is found to be statistically non-random only in close proximity to tidal extremes meaning that magnitude of tidal stress plays an important role in tidal triggering. A non-random tidal signal is observed for the reverse events. Along with a significant increase in earthquake rates around tidal Coulomb stress maxima, the strength of tidal correlation is found to be closely related to the amplitude of the peak tidal Coulomb stress (τp). The most effective tidal triggering is found for τp ≥ 1 kPa, which is much smaller than thresholds suggested for static and dynamic triggering of aftershocks.

  9. Tidal power in Argentina

    SciTech Connect

    Aisiks, E.G.

    1993-03-01

    This presentation describes the tidal power potential of Argentina and the current status of its utilization. The topics of the presentation include tidal power potential, electric production of the region and the Argentine share of production and consumption, conventional hydroelectric potential, economic feasibility of tidal power production, and the general design and feasibility of a tidal power plant planned for the San Jose Gulf.

  10. Restoring Fossil Creek

    ERIC Educational Resources Information Center

    Flaccus, Kathleen; Vlieg, Julie; Marks, Jane C.; LeRoy, Carri J.

    2004-01-01

    Fossil Creek had been dammed for the past 90 years, and plans were underway to restore the stream. The creek runs through Central Arizona and flows from the high plateaus to the desert, cutting through the same formations that form the Grand Canyon. This article discusses the Fossil Creek monitoring project. In this project, students and teachers…

  11. 77 FR 42714 - Eagle Creek Hydropower, LLC, Eagle Creek Land Resources, LLC, Eagle Creek Water Resources, LLC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    ... Energy Regulatory Commission Eagle Creek Hydropower, LLC, Eagle Creek Land Resources, LLC, Eagle Creek... No.: 9690-109. c. Date Filed: June 19, 2012. d. Applicants: Eagle Creek Hydropower, LLC; Eagle Creek... President-- Operations, Eagle Creek Hydropower, LLC, Eagle Creek Water Resources, LLC, Eagle Creek...

  12. Capturing American black ducks in tidal waters

    USGS Publications Warehouse

    Harrison, M.K.; Haramis, G.M.; Jorde, D.G.; Stotts, D.B.

    2000-01-01

    We modified conventional, funnel-entrance dabbling duck bait traps to increase captures for banding of American Black Ducks (Anas rubripes) in tidal saltmarsh habitats of Smith Island, Maryland, one of the few remaining strongholds for breeding Black Ducks in the Chesapeake Bay. Traps and trapping techniques were adapted to tidal creeks and refined to improve capture rate, reduce mortality, and minimize interference by gulls. Best results were achieved by synchronizing trapping with predawn, low-tide foraging patterns of Black Ducks. Trap entrances were critical to retaining ducks, and use of loafing platforms reduced overall mortality to 3% of captures per year. We captured 3071 Black Ducks during the 14-year period, 1984-199

  13. Shell Creek Summers

    ERIC Educational Resources Information Center

    Seier, Mark; Goedeken, Suzy

    2005-01-01

    In 2002 Shell Creek Watershed Improvement Group turned to the Newman Grove Public Schools' science department to help educate the public on water quality in the watershed and to establish a monitoring system that would be used to improve surface and groundwater quality in the creek's watershed. Nebraska Department of Environmental Quality provided…

  14. Adjacent segment disease.

    PubMed

    Virk, Sohrab S; Niedermeier, Steven; Yu, Elizabeth; Khan, Safdar N

    2014-08-01

    EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Understand the forces that predispose adjacent cervical segments to degeneration. 2. Understand the challenges of radiographic evaluation in the diagnosis of cervical and lumbar adjacent segment disease. 3. Describe the changes in biomechanical forces applied to adjacent segments of lumbar vertebrae with fusion. 4. Know the risk factors for adjacent segment disease in spinal fusion. Adjacent segment disease (ASD) is a broad term encompassing many complications of spinal fusion, including listhesis, instability, herniated nucleus pulposus, stenosis, hypertrophic facet arthritis, scoliosis, and vertebral compression fracture. The area of the cervical spine where most fusions occur (C3-C7) is adjacent to a highly mobile upper cervical region, and this contributes to the biomechanical stress put on the adjacent cervical segments postfusion. Studies have shown that after fusion surgery, there is increased load on adjacent segments. Definitive treatment of ASD is a topic of continuing research, but in general, treatment choices are dictated by patient age and degree of debilitation. Investigators have also studied the risk factors associated with spinal fusion that may predispose certain patients to ASD postfusion, and these data are invaluable for properly counseling patients considering spinal fusion surgery. Biomechanical studies have confirmed the added stress on adjacent segments in the cervical and lumbar spine. The diagnosis of cervical ASD is complicated given the imprecise correlation of radiographic and clinical findings. Although radiological and clinical diagnoses do not always correlate, radiographs and clinical examination dictate how a patient with prolonged pain is treated. Options for both cervical and lumbar spine ASD include fusion and/or decompression. Current studies are encouraging regarding the adoption of arthroplasty in spinal surgery, but more long

  15. Aeration for plant root respiration in a tidal marsh

    NASA Astrophysics Data System (ADS)

    Li, Hailong; Li, Ling; Lockington, David

    2005-06-01

    This paper investigates the tidal effects on aeration conditions for plant root respiration in a tidal marsh. We extend the work of Ursino et al. (2004) by using a two-phase model for air and water flows in the marsh. Simulations have been conducted to examine directly the link between the airflow dynamics and the aeration condition in the marsh soil. The results show that the effects of entrapped air on water movement in the vadose zone are significant in certain circumstances. Single-phase models based on Richards' equation, which neglect such effects, may not be adequate for quantifying the aeration condition in tidal marsh. The optimal aeration condition, represented by the maximum of the integral magnitude of tidally advected air mass (TAAM) flux, is found to occur near the tidal creek for the four soil textures simulated. This may explain the observation that some salt marsh plant species grow better near tidal creeks than in the inner marsh areas. Our analyses, based on the two-phase model and predicted TAAM flux magnitude, provide further insight into the "positive feedback" mechanism proposed by Ursino et al. (2004). That is, pioneer plants may grow successfully near the creek where the root aeration condition is optimal. The roots of the pioneer plants can soften and loosen the rhizosphere soil, which increases the evapotranspiration rate, the soil porosity, and absolute permeability and weakens the capillary effects. These, in turn, improve further the root aeration conditions and may lead to colonization by plants less resistant to anaerobic conditions.

  16. Aeration for plant root respiration in a tidal marsh

    NASA Astrophysics Data System (ADS)

    Li, Hailong; Li, Ling; Lockington, David

    2005-06-01

    This paper investigates the tidal effects on aeration conditions for plant root respiration in a tidal marsh. We extend the work of Ursino et al. (2004) by using a two-phase model for air and water flows in the marsh. Simulations have been conducted to examine directly the link between the airflow dynamics and the aeration condition in the marsh soil. The results show that the effects of entrapped air on water movement in the vadose zone are significant in certain circumstances. Single-phase models based on Richards' equation, which neglect such effects, may not be adequate for quantifying the aeration condition in tidal marsh. The optimal aeration condition, represented by the maximum of the integral magnitude of tidally advected air mass (TAAM) flux, is found to occur near the tidal creek for the four soil textures simulated. This may explain the observation that some salt marsh plant species grow better near tidal creeks than in the inner marsh areas. Our analyses, based on the two-phase model and predicted TAAM flux magnitude, provide further insight into the ``positive feedback'' mechanism proposed by Ursino et al. (2004). That is, pioneer plants may grow successfully near the creek where the root aeration condition is optimal. The roots of the pioneer plants can soften and loosen the rhizosphere soil, which increases the evapotranspiration rate, the soil porosity, and absolute permeability and weakens the capillary effects. These, in turn, improve further the root aeration conditions and may lead to colonization by plants less resistant to anaerobic conditions.

  17. Nutrient chemistry and hydrology of interstitial water in brackish tidal marshes of Chesapeake Bay

    NASA Astrophysics Data System (ADS)

    Jordan, Thomas E.; Correll, David L.

    1985-07-01

    Nutrient concentrations in interstitial water were measured throughout the year in two brackish tidal marshes differing in elevation and vegetation. At all sites, sulfate to chloride ratios were lowest during the fall. In contrast, dissolved ammonia, phosphate, organic nitrogen, and organic phosphorus concentrations did not vary seasonally but differed among sample sites. These nutrients were generally enriched in interstitial water relative to tidal water and those that were most enriched declined in concentration with increasing proximity to creeks. In the low elevation marsh, flow of interstitial water towards creek banks was traced with Rhodamine WT dye. Consequent seepage of interstitial water into the creek of the low marsh was estimated from continuous monitoring of water table heights and from measurements of hydraulic conductivity. The estimated seepage could account for a portion, probably less than half, of the tidal export of dissolved nutrients from the low marsh.

  18. Principal components granulometric analysis of tidally dominated depositional environments

    SciTech Connect

    Mitchell, S.W. ); Long, W.T. ); Friedrich, N.E. )

    1991-02-01

    Sediments often are investigated by using mechanical sieve analysis (at 1/4 or 1/2{phi} intervals) to identify differences in weight-percent distributions between related samples, and thereby, to deduce variations in sediment sources and depositional processes. Similar granulometric data from groups of surface samples from two siliciclastic estuaries and one carbonate tidal creek have been clustered using principal components analysis. Subtle geographic trends in tidally dominated depositional processes and in sediment sources can be inferred from the clusters. In Barnstable Harbor, Cape Cod, Massachusetts, the estuary can be subdivided into five major subenvironments, with tidal current intensities/directions and sediment sources (longshore transport or sediments weathering from the Sandwich Moraine) as controls. In Morro Bay, San Luis Obispo county, California, all major environments (beach, dune, bay, delta, and fluvial) can be easily distinguished; a wide variety of subenvironments can be recognized. On Pigeon Creek, San Salvador Island, Bahamas, twelve subenvironments can be recognized. Biogenic (Halimeda, Peneroplios, mixed skeletal), chemogenic (pelopids, aggregates), and detrital (lithoclastis skeletal), chemogenic (pelopids, aggregates), and detrital (lithoclastis of eroding Pleistocene limestone) are grain types which dominate. When combined with tidal current intensities/directions, grain sources produce subenvironments distributed parallel to tidal channels. The investigation of the three modern environments indicates that principal components granulometric analysis is potentially a useful tool in recognizing subtle changes in transport processes and sediment sources preserved in ancient depositional sequences.

  19. Disaster at Buffalo Creek. Family and character change at Buffalo Creek.

    PubMed

    Titchener, J L; Kapp, F T

    1976-03-01

    Psychiatric evaluation teams used observations of family interaction and psychoanalytically oriented individual interviews to study the psychological aftereffects of the 1972 Buffalo Creek disaster, a tidal wave of sludge and black water released by the collapse of a slag waste dam. Traumatic neurotic reactions were found in 80% of the survivors. Underlying the clinical picture were unresolved grief, survivor shame, and feelings of impotent rage and hopelessness. These clinical findings had persisted for the two years since the flood, and a definite symptom complex labeled the "Buffalo Creek syndrome" was pervasive. The methods used by the survivors to cope with the overwhelming impact of the disaster--first-order defenses, undoing, psychological conservatism, and dehumanization--actually preserved their symptoms and caused disabling character changes.

  20. Tidal Marsh Outwelling of Dissolved Organic Matter and Resulting Temporal Variability in Coastal Water Optical and Biogeochemical Properties

    NASA Technical Reports Server (NTRS)

    Tzortziou, Maria; Neale, Patrick J.; Megonigal, J. Patrick; Butterworth, Megan; Jaffe, Rudolf; Yamashita, Youhei

    2010-01-01

    Coastal wetlands are highly dynamic environments at the land-ocean interface where human activities, short-term physical forcings and intense episodic events result in high biological and chemical variability. Long being recognized as among the most productive ecosystems in the world, tidally-influenced coastal marshes are hot spots of biogeochemical transformation and exchange. High temporal resolution observations that we performed in several marsh-estuarine systems of the Chesapeake Bay revealed significant variability in water optical and biogeochemical characteristics at hourly time scales, associated with tidally-driven hydrology. Water in the tidal creek draining each marsh was sampled every hour during several semi-diurnal tidal cycles using ISCO automated samplers. Measurements showed that water leaving the marsh during ebbing tide was consistently enriched in dissolved organic carbon (DOC), frequently by more than a factor of two, compared to water entering the marsh during flooding tide. Estimates of DOC fluxes showed a net DOC export from the marsh to the estuary during seasons of both low and high biomass of marsh vegetation. Chlorophyll amounts were typically lower in the water draining the marsh, compared to that entering the marsh during flooding tide, suggesting that marshes act as transformers of particulate to dissolved organic matter. Moreover, detailed optical and compositional analyses demonstrated that marshes are important sources of optically and chemically distinctive, relatively complex, high molecular weight, aromatic-rich and highly colored dissolved organic compounds. Compared to adjacent estuarine waters, marsh-exported colored dissolved organic matter (CDOM) was characterized by considerably stronger absorption (more than a factor of three in some cases), larger DOC-specific absorption, lower exponential spectral slope, larger fluorescence signal, lower fluorescence per unit absorbance, and higher fluorescence at visible wavelengths

  1. Origin of water that discharges from Calf Creek Spring, Garfield County, Utah

    USGS Publications Warehouse

    Wilberg, Dale E.

    1995-01-01

    -term, sustainable source of water is the Navajo aquifer and not precipitation-derived runoff. Ground-water leakage from adjacent drainages could contribute to perennial flow in Calf Creek. Fractures modify the movement of ground water to discharge areas, such as Calf Creek Spring.

  2. Dynamics of suspended sediment exchange and transport in a degraded mangrove creek in Kenya.

    PubMed

    Kitheka, Johnson U; Ongwenyi, George S; Mavuti, Kenneth M

    2002-12-01

    This study focuses on sediment exchange dynamics in Mwache Creek, a shallow tidal mangrove wetland in Kenya. The surface area of the creek is 17 km2 at high water spring. The creek experiences semidiurnal tides with tidal ranges of 3.2 m and 1.4 m during spring and neap tides, respectively. The creek is ebb dominant in the frontwater zone main channel and is flood dominant in the backwater zone main channel. During rainy season, the creek receives freshwater and terrigenous sediments from the seasonal Mwache River. Heavy supply of terrigenous sediments during the El Niño of 1997-1998 led to the huge deposition of sediments (10(60 tonnes) in the wetland that caused massive destruction of the mangrove forest in the upper region. In this study, sea level, tidal discharges, tidal current velocities, salinity, total suspended sediment concentrations (TSSC) and particulate organic sediment concentrations (POSC) measured in stations established within the main channel and also within the mangrove forests, were used to determine the dynamics of sediment exchange between the frontwater and backwater zones of the main channel including also the exchange with mangrove forests. The results showed that during wet seasons, the high suspended sediment concentration associated with river discharge and tidal resuspension of fine channel-bed sediment accounts for the inflow of highly turbid water into the degraded mangrove forest. Despite the degradation of the mangrove forest, sediment outflow from the mangrove forest was considerably less than the inflow. This caused a net trapping of sediment in the wetland. The net import of the sediment dominated in spring tide during both wet and dry season and during neap tide in the wet season. However, as compared to heavily vegetated mangrove wetlands, the generally degraded Mwache Creek mangrove wetland sediment trapping efficiency is low as the average is about 30% for the highly degraded backwater zone mangrove forest and 65% in the

  3. Hydrology and model study of the proposed Prosperity Reservoir, Center Creek Basin, southwestern Missouri

    USGS Publications Warehouse

    Harvey, Edward Joseph; Emmett, Leo F.

    1980-01-01

    A reservoir has been proposed on Center Creek, Jasper County, southwestern Missouri. Ground-water levels in the limestone uplands adjacent to the reservoir will rise when the impoundment is completed. The site is a few miles upstream from the Oronogo-Duenweg belt in the Tri-State zinc district. Grove Creek joins Center Creek downstream from the reservoir separating it from the mining belt. A model study indicates water-level rises varying from about 20 feet near the reservoir to 0.5 to 1.0 foot in the southern part of the Grove Creek drainage basin. A significant rise in the water table adjacent to the reservoir could increase mine-water discharge if Grove Creek is not an effective drain. However, it is probable that Grove Creek is an effective drain, and the higher ground-water levels in the reservoir area will increase ground-water discharge to Grove Creek, and in turn, Center Creek. The increase in ground-water discharge to Grove Creek will have the beneficial effect of diluting mine-water discharge from the Oronogo-Duenweg belt during periods of low flow. (USGS)

  4. Tidal Power in France

    SciTech Connect

    Frau, J.P. )

    1993-03-01

    This presentation discusses the tidal power resource of France and the successes of the La Rance Plant. The topics of the presentation include power generation, adaptation of output to grid requirements, plant installation, environmental factors, La Rance success, and a review of major world wide tidal energy projects in the UK, Canada, South Korea, India, and Argentina.

  5. TIDEV: Tidal Evolution package

    NASA Astrophysics Data System (ADS)

    Cuartas-Restrepo, P.; Melita, M.; Zuluaga, J.; Portilla, B.; Sucerquia, M.; Miloni, O.

    2016-09-01

    TIDEV (Tidal Evolution package) calculates the evolution of rotation for tidally interacting bodies using Efroimsky-Makarov-Williams (EMW) formalism. The package integrates tidal evolution equations and computes the rotational and dynamical evolution of a planet under tidal and triaxial torques. TIDEV accounts for the perturbative effects due to the presence of the other planets in the system, especially the secular variations of the eccentricity. Bulk parameters include the mass and radius of the planet (and those of the other planets involved in the integration), the size and mass of the host star, the Maxwell time and Andrade's parameter. TIDEV also calculates the time scale that a planet takes to be tidally locked as well as the periods of rotation reached at the end of the spin-orbit evolution.

  6. Water budget for and nitrogen loads to Northeast Creek, Bar Harbor, Maine

    USGS Publications Warehouse

    Nielsen, M.G.

    2002-01-01

    The potential for nutrient enrichment to coastal estuaries on Mt. Desert Island, Maine, may affect the health of these important ecosystems at Acadia National Park. Inputs of water and nitrogen entering one of these coastal estuaries, Northeast Creek, and adjacent wetlands on Mt. Desert Island were quantified in a recent study conducted by the U.S. Geological Survey, in cooperation with the National Park Service. Streamflow and concentra-tions of nitrogen species in the four perennial streams entering the wetland/estuary system were measured monthly for 18 months to estimate loads and develop a water budget. Old Mill Brook was instrumented with a continuous-recording stream-flow gage; the MOVE.1 record-extension technique was used with this and several other nearby continuous gages to estimate daily surface-water inflow to the wetland. Inflow from ungaged basins was estimated from the unit-area yield calculated from data obtained from the gaged basins. Precipitation data collected at the National Atmospheric Deposition Program (NADP) site at Acadia National Park Headquarters and the Acadia National Park weather station were used to calculate atmospheric inputs. Evapotranspiration from the wetland was calculated using Fennessey and Vogel?s regionalized multivariate regression model of Penman-Montieth evapotranspiration. Geologic data collected in the field and taken from published geologic maps indicate that ground water probably does not contribute significantly to the water budget of this wetland system. Surface-water outflow from the wetland was not calculated because of the tidal nature of the outlet of the wetland and the difficulties associated with measuring flow in a tidal stream.

  7. Creation Of Constructed Tidal Flats Using Ocean Dredged Sediment

    NASA Astrophysics Data System (ADS)

    Park, S.; Yi, B.; Lee, I.; Sung, K.

    2007-12-01

    The enforcement of London dumping convention (1972) and protocols (1996) which are comprehensive assessment system for ocean dumping wastes needs environmentally sound treatment and/or reuse of dredged sediment. Creation of constructed tidal flats using dredged sediments could be one of the useful alternatives among other dredged sediment treatments. In this study, the pilot-scale constructed tidal flats with 4 different mixing ratio of ocean dredged sediment were constructed in Nakdong river estuary, Korea. The reed was transplanted from the adjacent reed community after construction, and then the survival and growth rate of the planted reed was measured. Also the changes of Chemical Oxygen Demand (COD), Ignition loss (IL), and the heterotrophic microbial numbers were monitored. The survival rate of the planted reed decreased as the mixing ratio of dredged sediment increased. The survival rate of reed in the constructed tidal flat with 100% dredged sediment was 54% while that in the tidal flat with 0% dredged sediment (original soil of Nakdong river estuary) was 90%. There was little difference of length and diameter of the reed shoot among the 4 different constructed tidal flats. 30% of COD and 9% of IL in the tidal flat with 100% dredged sediment decreased after 202 day, however, the consistent tendency in the change of COD and IL in the other tidal flats was not found possibly due to the open system. It was suggested that the construction of tidal flats using ocean dredged sediment can be possible considering the growth rate of transplanted reeds and the contaminated ocean dredged sediment might be biologically remediated considering the results of decrease of organic matter and increased heterotrophic microbial number in the tidal flat with 100% dredged sediment. However, the continuous monitoring on the vegetation and various environmental factors in the constructed tidal flats should be necessary to evaluate the success of creation of constructed flats using

  8. SF6 Tracer Release Study: A Contaminant Fate Study in Newtown Creek

    NASA Astrophysics Data System (ADS)

    Schmieder, P. J.; Ho, D. T.; Peter, S.; Simpson, H. J.; Flores, S.; Dugan, W. A.

    2004-12-01

    Newtown Creek is a 5.5km creek that discharges into the East River, a 25km strait connecting Long Island Sound to the north and the New York Harbor to the south. Surface runoff dominates the freshwater input into the creek, for natural tributaries no longer exist. The areas directly adjacent to the creek are highly industrialized, and New York City's largest Water Pollution Control Plant (WPCP) discharges directly into creek. In August 2004, we injected sulfur hexafluoride (SF6) into Newtown creek to study the fate of oil seeping into the creek from an underground oil spill and the fate of nutrient rich effluent from the WPCP. We monitored SF6 in Newtown Creek, the East River, and the Upper Bay of New York Harbor for 7 consecutive days following the injection in order to investigate the spreading patterns and transport mechanics of waters exiting the creek, and to determine the ultimate fate of the contaminants/solutes originating in Newtown Creek. Dissolved oxygen (DO) measurements were collected simultaneously with SF6 measurements. A strong DO gradient exists in the creek, where waters in the upper reaches are anoxic. We use SF6 data to calculate mean residence times for Newtown Creek waters. SF6 was detected above background concentrations approximately 15km to the south of the creek at the Verrazano Bridge only 1 day after the tracer injection. By combining the movements of the SF6 distribution, the position of the oxygen gradient, and the residence time of Newtown Creek water, we can determine a lower boundary for oxygen consumption rates.

  9. Jackson Creek Spillway modifications

    SciTech Connect

    Freitas, M.J.; Young, D.J.; McCloud, B.J.

    1995-12-31

    The Jackson Creek Spillway in Amador County, California has been modified in response to issues raised during the Federal Energy Regulatory Commission (FERC) mandated 5-year safety inspections. The calculated factors of safety for the Jackson Creek Spillway, under the probable maximum flood (PMF) and maximum credible earthquake (MCE) loading conditions, were below levels considered acceptable by the FERC and modifications to the structure were required. Woodward-Clyde Consultants, under contract to the East Bay Municipal Utility District (EBMUD), designed the modifications and in the summer and fall of 1994 the modifications to the Jackson Creek Spillway were successfully constructed with both FERC and California Division of Safety of Dams (DSOD) approval. This paper will summarize the design and construction issues, and discuss the lessons learned during modification of this 67-year-old structure.

  10. BEAVER CREEK WILDERNESS, KENTUCKY.

    USGS Publications Warehouse

    Englund, K.J.; Hammack, R.W.

    1984-01-01

    The Beaver Creek Wilderness, Kentucky, was studied. Coal is the most important mineral resource in the Beaver Creek Wilderness. The coal is tentatively ranked as high-volatile A bituminous, and like coal of this rank in nearby mining areas, it is primarily suitable for use as steam coal. The coal resources are estimated to total 8. 31 million short tons in beds greater than 14 in. thick. Nonmetallic minerals present in the Wilderness include limestone, shale, clay, and sandstone; these commodities are abundant outside the wilderness. The information available is not adequate for the assessment of the oil and gas resource potential of the Beaver Creek Wilderness. There is little likelihood for the occurrence of metallic mineral resources.

  11. Glaciotectonism and landsliding in Little Sandhill Creek, Alberta

    NASA Astrophysics Data System (ADS)

    Campbell, Ian A.; Evans, David J. A.

    1990-11-01

    Slope failure and gully erosion along Little Sandhill Creek, a tributary of the Red Deer River, Alberta, Canada, has exposed large stratigraphic sections in which the effects of glaciotectonism and landsliding are clearly revealed. Six main units are identified ranging from a deposit of coarse fluvial sands, through various glacial diamictons and gravels and sands, to postglacial fluvial and lacustrine (pond) and aeolian sediments. Incision by Little Sandhill Creek since late Wisconsinan deglaciation ca. 12,500 B.P., resulted in periodic landslides culminating in the main slope failure which occurred post ca. 5400 B.P. The slide was reactivated by irrigation water return flow from the adjacent prairie surface.

  12. Tidal alignment of galaxies

    NASA Astrophysics Data System (ADS)

    Blazek, Jonathan; Vlah, Zvonimir; Seljak, Uroš

    2015-08-01

    We develop an analytic model for galaxy intrinsic alignments (IA) based on the theory of tidal alignment. We calculate all relevant nonlinear corrections at one-loop order, including effects from nonlinear density evolution, galaxy biasing, and source density weighting. Contributions from density weighting are found to be particularly important and lead to bias dependence of the IA amplitude, even on large scales. This effect may be responsible for much of the luminosity dependence in IA observations. The increase in IA amplitude for more highly biased galaxies reflects their locations in regions with large tidal fields. We also consider the impact of smoothing the tidal field on halo scales. We compare the performance of this consistent nonlinear model in describing the observed alignment of luminous red galaxies with the linear model as well as the frequently used "nonlinear alignment model," finding a significant improvement on small and intermediate scales. We also show that the cross-correlation between density and IA (the "GI" term) can be effectively separated into source alignment and source clustering, and we accurately model the observed alignment down to the one-halo regime using the tidal field from the fully nonlinear halo-matter cross correlation. Inside the one-halo regime, the average alignment of galaxies with density tracers no longer follows the tidal alignment prediction, likely reflecting nonlinear processes that must be considered when modeling IA on these scales. Finally, we discuss tidal alignment in the context of cosmic shear measurements.

  13. Methodology for classification of geographical features with remote sensing images: Application to tidal flats

    NASA Astrophysics Data System (ADS)

    Revollo Sarmiento, G. N.; Cipolletti, M. P.; Perillo, M. M.; Delrieux, C. A.; Perillo, Gerardo M. E.

    2016-03-01

    Tidal flats generally exhibit ponds of diverse size, shape, orientation and origin. Studying the genesis, evolution, stability and erosive mechanisms of these geographic features is critical to understand the dynamics of coastal wetlands. However, monitoring these locations through direct access is hard and expensive, not always feasible, and environmentally damaging. Processing remote sensing images is a natural alternative for the extraction of qualitative and quantitative data due to their non-invasive nature. In this work, a robust methodology for automatic classification of ponds and tidal creeks in tidal flats using Google Earth images is proposed. The applicability of our method is tested in nine zones with different morphological settings. Each zone is processed by a segmentation stage, where ponds and tidal creeks are identified. Next, each geographical feature is measured and a set of shape descriptors is calculated. This dataset, together with a-priori classification of each geographical feature, is used to define a regression model, which allows an extensive automatic classification of large volumes of data discriminating ponds and tidal creeks against other various geographical features. In all cases, we identified and automatically classified different geographic features with an average accuracy over 90% (89.7% in the worst case, and 99.4% in the best case). These results show the feasibility of using freely available Google Earth imagery for the automatic identification and classification of complex geographical features. Also, the presented methodology may be easily applied in other wetlands of the world and perhaps employing other remote sensing imagery.

  14. Boulder Creek Study

    ERIC Educational Resources Information Center

    Bingaman, Deirdre; Eitel, Karla Bradley

    2010-01-01

    Boulder Creek runs literally in the backyard of Donnelly Elementary School and happens to be on the EPA list of impaired water bodies. Therefore, a unique opportunity for problem solving opened the door to an exciting chance for students to become scientists, while also becoming active in their community. With the help of the Idaho Department of…

  15. The Paint Creek Project.

    ERIC Educational Resources Information Center

    Northrop, David; Vonck, Beth

    1998-01-01

    Describes a summer program project designed and conducted by a mixed-age group of elementary children. Students collected data to determine whether a local stream was polluted, and interpretations of the data varied. An informational video about the project and the creek was produced. (PVD)

  16. Limits to Tidal Power

    NASA Astrophysics Data System (ADS)

    Garrett, C.

    2008-12-01

    Ocean tides have been proposed as a source of renewable energy, though the maximum available power may be shown to be only a fraction of the present dissipation rate of 3.5 TW, which is small compared with global insolation (nearly 105 TW), wind dissipation (103 TW), and even human power usage of 15 TW. Nonetheless, tidal power could be a useful contributor in some locations. Traditional use of tidal power, involving the trapping of water behind a barrage at high tide, can produce an average power proportional to the area of the headpond and the square of the tidal range; the power density is approximately 6 W per square meter for a tidal range of 10 m. Capital costs and fears of environmental damage have put barrage schemes in disfavor, with interest turning to the exploitation of strong tidal currents, using turbines in a manner similar to wind turbines. There is a limit to the available power, however, as adding turbines reduces the flow, ultimately reducing the power. For sinusoidal forcing of flow in a channel connecting two large open basins, the maximum available power may be shown to be given approximately by 0.2ρ g a Q_max, where ρ is the water density, g gravity, a the amplitude of the tidal sea level difference along the channel, and Q_max is the maximum volume flux in the natural state. The same formula applies if the channel is the entrance to a semi-enclosed basin, with a now the amplitude of the external tide. A flow reduction of approximately 40% is typically associated with the maximum power extraction. The power would be reduced if only smaller environmental changes are acceptable, and reduced further by drag on supporting structures, dissipation in turbine wakes, and internal inefficiencies. It can be suggested that the best use of strong, cold, tidal currents is to provide cooling water for nuclear reactors.

  17. Channel stability of Turkey Creek, Nebraska

    USGS Publications Warehouse

    Rus, David L.; Soenksen, Philip J.

    1998-01-01

    Channelization on Turkey Creek and its receiving stream, the South Fork Big Nemaha River, has disturbed the equilibrium of Turkey Creek and has led to channel-stability problems, such as degradation and channel widening, which pose a threat to bridges and land adjacent to the stream. As part of a multiagency study, the U.S. Geological Survey assessed channel stability at two bridge sites on upper and middle portions of Turkey Creek by analyzing streambed-elevation data for gradation changes, comparing recent cross-section surveys and historic accounts, identifying bank-failure blocks, and analyzing tree-ring samples. These results were compared to gradation data and trend results for a U.S. Geological Survey streamflow-gaging station near the mouth of Turkey Creek from a previous study. Examination of data on streambed elevations reveals that degradation has occurred. The streambed elevation declined 0.5 m at the upper site from 1967-97. The streambed elevation declined by 3.2 m at the middle site from 1948-97 and exposed 2 m of the pilings of the Nebraska Highway 8 bridge. Channel widening could not be verified at the two sites from 1967-97, but a historic account indicates widening at the middle site to be two to three times that of the 1949 channel width. Small bank failures were evident at the upper site and a 4-m-wide bank failure occurred at the middle site in 1987 according to tree ring analyses. Examination of streambed-elevation data from a previous study at the lower site reveals a statistically significant aggrading trend from 1958-93. Further examination of these data suggests minor degradation occurred until 1975, followed by aggradation.

  18. Marine ecological habitat: a case study on projected thermal power plant around Dharamtar Creek, India.

    PubMed

    Kulkarni, Vikrant A; Naidu, Velamala S; Jagtap, Tanaji G

    2011-03-01

    Estuaries and tidal creeks, harboring mangroves particularly, face tremendous anthropogenic pressures. Expansion of mega cities and the thermal power plants are generally proposed in the vicinity of estuaries and creek, due to the feasibility of intake and discharge of water for cooling. Discharges from such developments remain constant threat of increasing thermal pollution and affecting the quality of environment. The baseline information on prevailing quality of aquatic environment comes handy for understanding alterations due to such activities. Principle component analysis (PCA) revealed that temperature, pH, salinity, suspended solids, DO, BOD and phaeophytins are major parameters influencing the creek system. Heated effluents may have direct and adverse impacts on these parameters, altering biotic constituents. Hence, periodic and detailed observations are necessary to estimate exact response of biotic communities to changing environment. The present paper is based on case study, projecting a power plant in the vicinity of major mangrove habitats of Dharamtar creek.

  19. Marine ecological habitat: a case study on projected thermal power plant around Dharamtar Creek, India.

    PubMed

    Kulkarni, Vikrant A; Naidu, Velamala S; Jagtap, Tanaji G

    2011-03-01

    Estuaries and tidal creeks, harboring mangroves particularly, face tremendous anthropogenic pressures. Expansion of mega cities and the thermal power plants are generally proposed in the vicinity of estuaries and creek, due to the feasibility of intake and discharge of water for cooling. Discharges from such developments remain constant threat of increasing thermal pollution and affecting the quality of environment. The baseline information on prevailing quality of aquatic environment comes handy for understanding alterations due to such activities. Principle component analysis (PCA) revealed that temperature, pH, salinity, suspended solids, DO, BOD and phaeophytins are major parameters influencing the creek system. Heated effluents may have direct and adverse impacts on these parameters, altering biotic constituents. Hence, periodic and detailed observations are necessary to estimate exact response of biotic communities to changing environment. The present paper is based on case study, projecting a power plant in the vicinity of major mangrove habitats of Dharamtar creek. PMID:21882658

  20. Modeling pesticide fate in a small tidal estuary

    USGS Publications Warehouse

    McCarthy, A.M.; Bales, J.D.; Cope, W.G.; Shea, D.

    2007-01-01

    The exposure analysis modeling system (EXAMS), a pesticide fate model developed by the U.S. Environmental Protection Agency, was modified to model the fate of the herbicides atrazine and metolachlor in a small tidally dominated estuary (Bath Creek) in North Carolina, USA where freshwater inflow accounts for only 3% of the total flow. The modifications simulated the changes that occur during the tidal cycle in the estuary, scenarios that are not possible with the original EXAMS model. Two models were created within EXAMS, a steady-state model and a time-variant tidally driven model. The steady-state model accounted for tidal flushing by simply altering freshwater input to yield an estuary residence time equal to that measured in Bath Creek. The tidal EXAMS model explicitly incorporated tidal flushing by modifying the EXAMS code to allow for temporal changes in estuary physical attributes (e.g., volume). The models were validated with empirical measurements of atrazine and metolachlor concentrations in the estuary shortly after herbicide application in nearby fields and immediately following a rain event. Both models provided excellent agreement with measured concentrations. The steady-state EXAMS model accurately predicted atrazine concentrations in the middle of the estuary over the first 3 days and under-predicted metolachlor by a factor of 2-3. The time-variant, tidally driven EXAMS model accurately predicted the rise and plateau of both herbicides over the 6-day measurement period. We have demonstrated the ability of these modified EXAMS models to be useful in predicting pesticide fate and exposure in small tidal estuaries. This is a significant improvement and expansion of the application of EXAMS, and given the wide use of EXAMS for surface water quality modeling by both researchers and regulators and the ability of EXAMS to interface with terrestrial models (e.g., pesticide root zone model) and bioaccumulation models, we now have an easily-accessible and

  1. AN APPROACH FOR CLASSIFYING TIDAL REGIMES BASED ON TIDAL CONSTITUENTS

    EPA Science Inventory

    Tidal fluctuations can be one of the dominant physical processes in estuaries. This paper presents a numerical classification of tidal regimes that can be used to summarize local conditions and facilitate comparisons among locations. Tide predictions are customarily calculated ...

  2. Tidal Dwarf Galaxies

    NASA Astrophysics Data System (ADS)

    Duc, P.-A.; Mirabel, I. F.; Brinks, E.

    The life and evolution of galaxies are dramatically affected by environmental effects. Interactions with the intergalactic medium and collisions with companions cause major perturbations in the morphology and contents of galaxies: in particular stars and gas clouds may be gravitationally pulled out from their parent galaxies during tidal encounters, forming rings, tails and bridges. This debris of collisions lies at the origin of a new generation of small galaxies, the so-called "tidal dwarf galaxies" (TDGs). The authors have carried out multi-wavelength observations of some 20 TDGs. These systems are made of two stellar components: young stars, formed from the recent collapse of expelled H I clouds, and an older stellar population, tidally pulled out from the disks of their interacting parent galaxies. In the observed TDGs, the current star formation episode is fuelled by a large reservoir of H I gas and is younger than 10 Myr.

  3. WELCOME CREEK WILDERNESS, MONTANA.

    USGS Publications Warehouse

    Lidke, D.J.; Close, T.J.

    1984-01-01

    Mineral-resource surveys indicate probable or substantiated mineral-resource potential for small amounts of gold and other metals. Areas of alluvium in Welcome Creek and in part of Rock Creek are classed as having probable and substantiated mineral-resource potential for small quantities of gold in small and scattered placers and in placer tailings. A small area which contains the Cleveland mine, on Cleveland Mountain, near the west border of the wilderness was classed as having probable mineral-resource potential for silver and gold in veins. Although green mudstone strata that often are favorable hosts for stratabound copper occurrences were found in the northeast part of the wilderness, no copper deposits were found and these studies indicate little likelihood for the occurrence of copper resources. The nature of the geologic terrain indicates that there is little likelihood of the occurrence of energy resources.

  4. Tidally Heated Terrestrial Exoplanets

    NASA Astrophysics Data System (ADS)

    Henning, Wade Garrett

    This work models the surface and internal temperatures for hypothetical terrestrial planets in situations involving extreme tidal heating. The feasibility of such planets is evaluated in terms of the orbital perturbations that may give rise to them, their required proximity to a hoststar, and the potential for the input tidal heating to cause significant partial melting of the mantle. Trapping terrestrial planets into 2:1 resonances with migrating Hot Jupiters is considered as a reasonable way for Earth-like worlds to both maintain high eccentricities and to move to short enough orbital periods (1-20 days) for extreme tidal heating to occur. Secular resonance and secular orbital perturbations may support moderate tidal heating at a low equilibrium eccentricity. At orbital periods below 10-30 days, with eccentricities from 0.01 to 0.1, tidal heat may greatly exceed radiogenic heat production. It is unlikely to exceed insolation, except when orbiting very low luminosity hosts, and thus will have limited surface temperature expression. Observations of such bodies many not be able to detect tidal surface enhancements given a few percent uncertainty in albedo, except on the nightside of spin synchronous airless objects. Otherwise detection may occur via spectral detection of hotspots or high volcanic gas concentrations including sulfur dioxide and hydrogen sulfide. The most extreme cases may be able to produce magma oceans, or magma slush mantles with up to 40-60% melt fractions. Tides may alter the habitable zones for smaller red dwarf stars, but are generally detrimental. Multiple viscoelastic models, including the Maxwell, Voigt-Kelvin, Standard Anelastic Solid, and Burgers rheologies are explored and applied to objects such as Io and the super-Earth planet GJ 876d. The complex valued Love number for the Burgers rheology is derived and found to be a useful improvement when modeling the low temperature behavior of tidal bodies, particularly during low eccentricity

  5. Tidal power plants in Russia

    SciTech Connect

    Bernshtein, L.B. )

    1994-01-01

    This article examines the performance of tidal power plants in Russia and the expansion of tidal plant to new sites. The topics of the article include remote construction and transport techniques, pilot plant performance, economics and payback, and a review of global tidal power plant designs that are on hold due to economic problems relating to the global economy.

  6. Final Report: Five years of monitoring reconstructed freshwater tidal wetlands in the urban Anacostia River (2000-2004)

    USGS Publications Warehouse

    Hammerschlag, R.S.; Baldwin, A.H.; Krafft, C.C.; Neff, K.P.; Paul, M.M.; Brittingham, K.D.; Rusello, K.; Hatfield, J.S.

    2006-01-01

    The Anacostia River in Washington, D.C. USA consisted of over 809 hectares (2000 acres) of freshwater tidal wetlands before mandatory dredging removed most of them in the first half of the 20th century. Much of this13 kilometer (8 mile) reach was transferred to the National Park Service (NPS). Planning processes in the 1980?s envisioned a restoration (rejuvenation) of some wetlands for habitat, aesthetics, water quality and interpretative purposes. Subsequently, the U.S. Army Corps of Engineers in a cost share agreement with the District of Columbia reconstructed wetlands on NPS lands at Kenilworth - 12.5 hectares (1993), Kingman - 27 hectares (2000), a Fringe Marsh - 6.5 hectares (2003) and is currently constructing Heritage Marsh - 2.5 hectares (2005/2006). The USGS Patuxent Wildlife Research Center in conjunction with the University of Maryland Biological Engineering Department was contracted to conduct post-reconstruction monitoring (2000-2004) to document the relative success and progress of the Kingman Marsh reconstruction primarily based on vegetative response but also in conjunction with seed bank and soil characteristics. Results from Kingman were compared to Kenilworth Marsh (reconstructed 7 years prior), Dueling Creek Marsh (last best remaining freshwater tidal wetland bench in the urbanized Anacostia watershed) and Patuxent River Marsh (in a more natural adjacent watershed). Vegetation establishment was initially strong at Kingman, but declined rapidly as measured by cover, richness, diversity , etc. under grazing pressure from resident Canada geese and associated reduction in sediment levels. This decline did not occur at the other wetlands. The decline occurred despite a substantial seed bank that was sustained primarily be water born propagules. Soil development, as true for most juvenile wetlands, was slow with almost no organic matter accumulation. By 2004 only two of 7 planted species remained (mostly Peltandra virginica) at Kingman which did

  7. Anthropogenic changes to the tidal channel network, sediment rerouting, and social implications in southwest Bangladesh

    NASA Astrophysics Data System (ADS)

    Wilson, C.; Goodbred, S. L., Jr.; Sams, S.; Small, C.

    2015-12-01

    The tidal channel network in southwest Bangladesh has been undergoing major adjustment in response to anthropogenic modification over the past few decades. Densely inhabited, agricultural islands that have been embanked to protect against inundation by tides, river flooding, and storm surges (i.e., polders) preclude tidal exchange and sedimentation. Studies reveal this results in elevation deficits relative to mean high water, endangering local communities when embankment failures occur (e.g., during storms, lateral channel erosion). In addition, many studies suggest that the decrease in tidal prism and associated change in hydrodynamics from poldering causes shoaling in remaining tidal channels, which can cause a disruption in transportation. The widespread closure and conversion of tidal channel areas to profitable shrimp aquaculture is also prevalent in this region. In this study, we quantify the direct closure of tidal channels due to poldering and shrimp aquaculture using historical Landsat and Google Earth imagery, and analyze the morphologic adjustment of the tidal channel network due to these perturbations. In the natural Sundarbans mangrove forest, the tidal channel network has remained relatively constant since the 1970s. In contrast, construction of polders removed >1000 km of primary tidal creeks and >90 km2 has been reclaimed outside of polders through infilling and closure of formerly-active, higher order conduit channels now used for shrimp aquaculture. Field validation confirm tidal restriction by large sluice gates is prevalent, favoring local channel siltation at rates up to 20cm/yr. With the impoundment of primary creeks and closure of 30-60% of conduit channels in the study area, an estimated 1,400 x 106 m3 of water has been removed from the tidal prism and potentially redirected within remaining channels. This has significant implications for tidal amplification in this region. Further, we estimate that 12.3 x 106 MT of sediment annually

  8. 33 CFR 334.500 - St. Johns River, Atlantic Ocean, Sherman Creek; restricted areas and danger zone, Naval Station...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... at 33 CFR 329, within the area bounded by a line connecting the following coordinates: Commencing... CFR part 329, to include Sherman Creek, its tributaries and associated tidal marshes located within... encompass all navigable waters of the United States, as defined at 33 CFR part 329, within the area...

  9. 33 CFR 334.500 - St. Johns River, Atlantic Ocean, Sherman Creek; restricted areas and danger zone, Naval Station...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... at 33 CFR 329, within the area bounded by a line connecting the following coordinates: Commencing... CFR part 329, to include Sherman Creek, its tributaries and associated tidal marshes located within... encompass all navigable waters of the United States, as defined at 33 CFR part 329, within the area...

  10. 33 CFR 334.500 - St. Johns River, Atlantic Ocean, Sherman Creek; restricted areas and danger zone, Naval Station...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... at 33 CFR 329, within the area bounded by a line connecting the following coordinates: Commencing... CFR part 329, to include Sherman Creek, its tributaries and associated tidal marshes located within... encompass all navigable waters of the United States, as defined at 33 CFR part 329, within the area...

  11. 33 CFR 334.500 - St. Johns River, Atlantic Ocean, Sherman Creek; restricted areas and danger zone, Naval Station...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... at 33 CFR 329, within the area bounded by a line connecting the following coordinates: Commencing... CFR part 329, to include Sherman Creek, its tributaries and associated tidal marshes located within... encompass all navigable waters of the United States, as defined at 33 CFR part 329, within the area...

  12. 216. Construction of the Back Creek Bridge over Back Creek ...

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

    216. Construction of the Back Creek Bridge over Back Creek and Virginia Route 613. This is a good example of a precast concrete girder bridge. Note the fallen beam at the far end. - Blue Ridge Parkway, Between Shenandoah National Park & Great Smoky Mountains, Asheville, Buncombe County, NC

  13. Fracture history of the Divide Creek and Wolf Creek anticlines and its relation to Laramide basin-margin tectonism, southern Piceance basin, northwestern Colorado

    SciTech Connect

    Grout, M.A.; Verbeek, E.R.

    1992-01-01

    The Divide Creek and Wolf Creek anticlines are two north-northwest-trending, gas-producing intrabasin folds near the eastern margin of the Piceance basin of northwestern Colorado. Natural gas is produced principally from fractured sandstone reservoirs and coals of the Upper Cretaceous Mesaverde Group, the uppermost part of which is exposed sparingly on both folds. The southern part of the Piceance basin was selected for study because it contains obvious intrabasin folds, the Divide Creek and Wolf Creek anticlines, of previously unknown origin adjacent to the tectonically thrusted and folded eastern basin margin. The origin and tectonics of the anticlines are explored in this paper. New seismic and gravity data show that the anticlines are products of late Laramide thrusting. The distribution of several fracture sets discussed in this report are related to this deformation.

  14. The Beaver Creek story

    USGS Publications Warehouse

    Doyle, W.H.; Whitworth, B.G.; Smith, G.F.; Byl, T.D.

    1996-01-01

    Beaver Creek watershed in West Tennessee includes about 95,000 acres of the Nation's most productive farmland and most highly erodible soils. In 1989 the U.S. Geological Survey, in cooperation with the Tennessee Department of Agriculture, began a study to evaluate the effect of agricultural activities on water quality in the watershed and for best management practices designed to reduce agricultural nonpoint-source pollution. Agrichemical monitoring included testing the soils, ground water, and streams at four farm sites ranging from 27 to 420 acres. Monitoring stations were operated downstream to gain a better understanding of the water chemistry as runoff moved from small ditches into larger streams to the outlet of the Beaver Creek watershed. Prior to the implementation of best management practices at one of the farm study sites, some storms produced an average suspended-sediment concentration of 70,000 milligrams per liter. After the implementation of BMP's, however, the average value never exceeded 7,000 milligrams per liter. No-till crop production was the most effective best management practice for conserving soil on the farm fields tested. A natural bottomland hardwood wetland and a constructed wetland were evaluated as instream resource-management systems. The wetlands improved water quality downstream by acting as a filter and removing a significant amount of nonpoint-source pollution from the agricultural runoff. The constructed wetland reduced the sediment, pesticide, and nutrient load by approximately 50 percent over a 4-month period. The results of the Beaver Creek watershed study have increased the understanding of the effects of agriculture on water resources. Study results also demonstrated that BMP's do protect and improve water quality.

  15. Water-Quality Characteristics of Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek, Grand Teton National Park, Wyoming, 2006

    USGS Publications Warehouse

    Clark, Melanie L.; Wheeler, Jerrod D.; O'Ney, Susan E.

    2007-01-01

    To address water-resource management objectives of the National Park Service in Grand Teton National Park, the U.S. Geological Survey in cooperation with the National Park Service has conducted water-quality sampling on streams in the Snake River headwaters area. A synoptic study of streams in the western part of the headwaters area was conducted during 2006. Sampling sites were located on Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek. Sampling events in June, July, August, and October were selected to characterize different hydrologic conditions and different recreational-use periods. Stream samples were collected and analyzed for field measurements, major-ion chemistry, nutrients, selected trace elements, pesticides, and suspended sediment. Water types of Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek were calcium bicarbonate. Dissolved-solids concentrations were dilute in Cottonwood Creek and Taggart Creek, which drain Precambrian-era rocks and materials derived from these rocks. Dissolved-solids concentrations ranged from 11 to 31 milligrams per liter for samples collected from Cottonwood Creek and Taggart Creek. Dissolved-solids concentrations ranged from 55 to 130 milligrams per liter for samples collected from Lake Creek and Granite Creek, which drain Precambrian-era rocks and Paleozoic-era rocks and materials derived from these rocks. Nutrient concentrations generally were small in samples collected from Cottonwood Creek, Taggart Creek, Lake Creek, and Granite Creek. Dissolved-nitrate concentrations were the largest in Taggart Creek. The Taggart Creek drainage basin has the largest percentage of barren land cover of the basins, and subsurface waters of talus slopes may contribute to dissolved-nitrate concentrations in Taggart Creek. Pesticide concentrations, trace-element concentrations, and suspended-sediment concentrations generally were less than laboratory reporting levels or were small for all samples. Water

  16. Subsurface flow and vegetation patterns in tidal environments

    NASA Astrophysics Data System (ADS)

    Ursino, Nadia; Silvestri, Sonia; Marani, Marco

    2004-05-01

    Tidal environments are characterized by a complex interplay of hydrological, geomorphic, and biological processes, and their understanding and modeling thus require the explicit description of both their biotic and abiotic components. In particular, the presence and spatial distribution of salt marsh vegetation (a key factor in the stabilization of the surface soil) have been suggested to be related to topographic factors and to soil moisture patterns, but a general, process-based comprehension of this relationship has not yet been achieved. The present paper describes a finite element model of saturated-unsaturated subsurface flow in a schematic salt marsh, driven by tidal fluctuations and evapotranspiration. The conditions leading to the establishment of preferentially aerated subsurface zones are studied, and inferences regarding the development and spatial distribution of salt marsh vegetation are drawn, with important implications for the overall ecogeomorphological dynamics of tidal environments. Our results show that subsurface water flow in the marsh induces complex water table dynamics, even when the tidal forcing has a simple sinusoidal form. The definition of a space-dependent aeration time is then proposed to characterize root aeration. The model shows that salt marsh subsurface flow depends on the distance from the nearest creek or channel and that the subsurface water movement near tidal creeks is both vertical and horizontal, while farther from creeks, it is primarily vertical. Moreover, the study shows that if the soil saturated conductivity is relatively low (10-6 m s-1, values quite common in salt marsh areas), a persistently unsaturated zone is present below the soil surface even after the tide has flooded the marsh; this provides evidence of the presence of an aerated layer allowing a prolonged presence of oxygen for aerobic root respiration. The results further show that plant transpiration increases the extent and persistence of the aerated

  17. 75 FR 27332 - AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC; Eagle Creek Water Resources, LLC; Eagle Creek Land...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-14

    ... Energy Regulatory Commission AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC; Eagle Creek Water Resources... Creek Hydro Power, LLC, Eagle Creek Water Resources, LLC, and Eagle Creek Land Resources, LLC.... For the transferee: Mr. Paul Ho, Eagle Creek Hydro Power, LLC, Eagle Creek Water Resources, LLC,...

  18. Hydrologic data for Soldier Creek Basin, Kansas

    USGS Publications Warehouse

    Carswell, William J.

    1978-01-01

    Selected hydrologic data collected in the Soldier Creek basin in northeastern Kansas are available on magnetic tape in card-image format. Data on the tape include water discharge in fifteen-minute and daily time intervals; rainfall in fifteen-minute and daily time intervals; concentrations and particle sizes of suspended sediment; particle sizes of bed material; ground-water levels; and chemical quality of water in concentrations of selected constituents. The data-collection system includes: (1) 7 recording streamflow stations; (2) 5 recording rainfall stations; (3) 51 nonrecording rainfall stations located within and adjacent to the basin; (4) 31 ground-water observation wells (two recording); and (5) intermittent chemical quality of water and sediment sampling sites. Examples of the information on magnetic tape for each type of data collected are presented in computer-printout format. (Woodard-USGS)

  19. Tidal disruption events

    NASA Astrophysics Data System (ADS)

    Levan, A.

    2014-07-01

    Tidal disruption events (TDEs) provide a powerful probe of many astrophysical processes. They occur when the powerful tidal field around a black hole disrupts a passing star which is subsequently accreted. The resulting signal is a powerful X-ray, UV/opt and possibly even radio source, that provides us with a view of accretion aroud supermassive black holes from switch-on to switch-off over the timescale of years. TDEs probe accretion physics, the ubquity of black holes in galactic nuclei and dynamics in their cores, offering a novel route to addressing these issues. I will review observations of TDEs over the past decade, outlining how samples of candidates have been gradually building, and how they can be identified against other more common transient events. I will also discuss the implications of the discovery of a population of TDEs apparently launching relativisitc jets, and how these powerful transients may be detected in upcoming X-ray to radio surveys.

  20. Developments in tidal power

    NASA Astrophysics Data System (ADS)

    Charlier, R. H.

    Successful, planned, and potential tidal power plants and sites are discussed. Units are in operation in France and Russia, with the French plant using reversible blade turbines being used as a design guide for plants in Argentina and Australia. The U.S. is studying the feasibility of a plant in Passamaquaddy Bay, and Canada is pursuing construction of a plant in the Bay of Fundy. The Severn River in Great Britain is receiving a site study, and over a hundred plants have been built as local power systems in China. Bulb-type turbines, which enhance the volume emptying and filling the retaining basin, are considered as the highest performing power unit. Simpler one-way flow turbines have been suggested as more economical to install. Governmental, institutional, and investor impediments to tidal power plant are explored.

  1. Developments in tidal power

    SciTech Connect

    Charlier, R.H.

    1982-08-01

    Marine power has been the subject of numerous conferences and an impressive number of studies has considered schemes to harness ocean energy. Recently some attention has also been given to small marine power projects. Thermal difference, tides and waves appear to offer the greatest immediate promise, but so far only tidal power has been tapped on a large scale. Since completion of the Rance plant new concepts have been developed and new schemes designed. Some aspects are briefly examined here.

  2. Ship Creek bioassessment investigations

    SciTech Connect

    Cushing, C.E.; Mueller, R.P.; Murphy, M.T.

    1995-06-01

    Pacific Northwest Laboratory (PNL) was asked by Elmendorf Air Force Base (EAFB) personnel to conduct a series of collections of macroinvertebrates and sediments from Ship Creek to (1) establish baseline data on these populations for reference in evaluating possible impacts from Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) activities at two operable units, (2) compare current population indices with those found by previous investigations in Ship Creek, and (3) determine baseline levels of concentrations of any contaminants in the sediments associated with the macroinvertebrates. A specific suite of indices established by the US Environmental Protection Agency (EPA) was requested for the macroinvertebrate analyses; these follow the Rapid Bioassessment Protocol developed by Plafkin et al. (1989) and will be described. Sediment sample analyses included a Microtox bioassay and chemical analysis for contaminants of concern. These analyses included, volatile organic compounds, total gasoline and diesel hydrocarbons (EPA method 8015, CA modified), total organic carbon, and an inductive-coupled plasma/mass spectrometry (ICP/MS) metals scan. Appendix A reports on the sediment analyses. The Work Plan is attached as Appendix B.

  3. Kiowa Creek Switching Station

    SciTech Connect

    Not Available

    1990-03-01

    The Western Area Power Administration (Western) proposes to construct, operate, and maintain a new Kiowa Creek Switching Station near Orchard in Morgan County, Colorado. Kiowa Creek Switching Station would consist of a fenced area of approximately 300 by 300 feet and contain various electrical equipment typical for a switching station. As part of this new construction, approximately one mile of an existing 115-kilovolt (kV) transmission line will be removed and replaced with a double circuit overhead line. The project will also include a short (one-third mile) realignment of an existing line to permit connection with the new switching station. In accordance with the Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the National Environmental Policy Act of 1969 (NEPA), 40 CFR Parts 1500--1508, the Department of Energy (DOE) has determined that an environmental impact statement (EIS) is not required for the proposed project. This determination is based on the information contained in this environmental assessment (EA) prepared by Western. The EA identifies and evaluates the environmental and socioeconomic effects of the proposed action, and concludes that the advance impacts on the human environment resulting from the proposed project would not be significant. 8 refs., 3 figs., 1 tab.

  4. Relativistic tidal disruption events

    NASA Astrophysics Data System (ADS)

    Levan, A.

    2012-12-01

    In March 2011 Swift detected an extremely luminous and long-lived outburst from the nucleus of an otherwise quiescent, low luminosity (LMC-like) galaxy. Named Swift J1644+57, its combination of high-energy luminosity (1048 ergs s-1 at peak), rapid X-ray variability (factors of >100 on timescales of 100 seconds) and luminous, rising radio emission suggested that we were witnessing the birth of a moderately relativistic jet (Γ ˜ 2 - 5), created when a star is tidally disrupted by the supermassive black hole in the centre of the galaxy. A second event, Swift J2058+0516, detected two months later, with broadly similar properties lends further weight to this interpretation. Taken together this suggests that a fraction of tidal disruption events do indeed create relativistic outflows, demonstrates their detectability, and also implies that low mass galaxies can host massive black holes. Here, I briefly outline the observational properties of these relativistic tidal flares observed last year, and their evolution over the first year since their discovery.

  5. Tidal Venuses: triggering a climate catastrophe via tidal heating.

    PubMed

    Barnes, Rory; Mullins, Kristina; Goldblatt, Colin; Meadows, Victoria S; Kasting, James F; Heller, René

    2013-03-01

    Traditionally, stellar radiation has been the only heat source considered capable of determining global climate on long timescales. Here, we show that terrestrial exoplanets orbiting low-mass stars may be tidally heated at high-enough levels to induce a runaway greenhouse for a long-enough duration for all the hydrogen to escape. Without hydrogen, the planet no longer has water and cannot support life. We call these planets "Tidal Venuses" and the phenomenon a "tidal greenhouse." Tidal effects also circularize the orbit, which decreases tidal heating. Hence, some planets may form with large eccentricity, with its accompanying large tidal heating, and lose their water, but eventually settle into nearly circular orbits (i.e., with negligible tidal heating) in the habitable zone (HZ). However, these planets are not habitable, as past tidal heating desiccated them, and hence should not be ranked highly for detailed follow-up observations aimed at detecting biosignatures. We simulated the evolution of hypothetical planetary systems in a quasi-continuous parameter distribution and found that we could constrain the history of the system by statistical arguments. Planets orbiting stars with masses<0.3 MSun may be in danger of desiccation via tidal heating. We have applied these concepts to Gl 667C c, a ∼4.5 MEarth planet orbiting a 0.3 MSun star at 0.12 AU. We found that it probably did not lose its water via tidal heating, as orbital stability is unlikely for the high eccentricities required for the tidal greenhouse. As the inner edge of the HZ is defined by the onset of a runaway or moist greenhouse powered by radiation, our results represent a fundamental revision to the HZ for noncircular orbits. In the appendices we review (a) the moist and runaway greenhouses, (b) hydrogen escape, (c) stellar mass-radius and mass-luminosity relations, (d) terrestrial planet mass-radius relations, and (e) linear tidal theories.

  6. Overland Tidal Power Generation Using Modular Tidal Prism

    SciTech Connect

    Khangaonkar, Tarang; Yang, Zhaoqing; Geerlofs, Simon H.; Copping, Andrea

    2010-03-01

    Naturally occurring sites with sufficient kinetic energy suitable for tidal power generation with sustained currents > 1 to 2 m/s are relatively rare. Yet sites with greater than 3 to 4 m of tidal range are relatively common around the U.S. coastline. Tidal potential does exist along the shoreline but is mostly distributed, and requires an approach which allows trapping and collection to also be conducted in a distributed manner. In this paper we examine the feasibility of generating sustainable tidal power using multiple nearshore tidal energy collection units and present the Modular Tidal Prism (MTP) basin concept. The proposed approach utilizes available tidal potential by conversion into tidal kinetic energy through cyclic expansion and drainage from shallow modular manufactured overland tidal prisms. A preliminary design and configuration of the modular tidal prism basin including inlet channel configuration and basin dimensions was developed. The unique design was shown to sustain momentum in the penstocks during flooding as well as ebbing tidal cycles. The unstructured-grid finite volume coastal ocean model (FVCOM) was used to subject the proposed design to a number of sensitivity tests and to optimize the size, shape and configuration of MTP basin for peak power generation capacity. The results show that an artificial modular basin with a reasonable footprint (≈ 300 acres) has the potential to generate 10 to 20 kw average energy through the operation of a small turbine located near the basin outlet. The potential of generating a total of 500 kw to 1 MW of power through a 20 to 40 MTP basin tidal power farms distributed along the coastline of Puget Sound, Washington, is explored.

  7. Tidal Venuses: triggering a climate catastrophe via tidal heating.

    PubMed

    Barnes, Rory; Mullins, Kristina; Goldblatt, Colin; Meadows, Victoria S; Kasting, James F; Heller, René

    2013-03-01

    Traditionally, stellar radiation has been the only heat source considered capable of determining global climate on long timescales. Here, we show that terrestrial exoplanets orbiting low-mass stars may be tidally heated at high-enough levels to induce a runaway greenhouse for a long-enough duration for all the hydrogen to escape. Without hydrogen, the planet no longer has water and cannot support life. We call these planets "Tidal Venuses" and the phenomenon a "tidal greenhouse." Tidal effects also circularize the orbit, which decreases tidal heating. Hence, some planets may form with large eccentricity, with its accompanying large tidal heating, and lose their water, but eventually settle into nearly circular orbits (i.e., with negligible tidal heating) in the habitable zone (HZ). However, these planets are not habitable, as past tidal heating desiccated them, and hence should not be ranked highly for detailed follow-up observations aimed at detecting biosignatures. We simulated the evolution of hypothetical planetary systems in a quasi-continuous parameter distribution and found that we could constrain the history of the system by statistical arguments. Planets orbiting stars with masses<0.3 MSun may be in danger of desiccation via tidal heating. We have applied these concepts to Gl 667C c, a ∼4.5 MEarth planet orbiting a 0.3 MSun star at 0.12 AU. We found that it probably did not lose its water via tidal heating, as orbital stability is unlikely for the high eccentricities required for the tidal greenhouse. As the inner edge of the HZ is defined by the onset of a runaway or moist greenhouse powered by radiation, our results represent a fundamental revision to the HZ for noncircular orbits. In the appendices we review (a) the moist and runaway greenhouses, (b) hydrogen escape, (c) stellar mass-radius and mass-luminosity relations, (d) terrestrial planet mass-radius relations, and (e) linear tidal theories. PMID:23537135

  8. Recognition of synodic and tropical tidal periodicities in tidal rhythmites

    SciTech Connect

    Archer, A.W. ); Kvale, E.P. ); Johnson, H.P. )

    1990-05-01

    Tidal processes are capable of producing bedding that records individual tidal events; however, only within the last decade have tidal cycles, such as neap-spring periodicities become widely recognized. Such cycles have been documented within thinly laminated, vertically accreted siltstones. The laminae exhibit systematic patterns of thickening and thinning that have been equated to the lunar orbital period (synodic month). However, modem tides are subject to periodicities other than the synodic month and such additional periods can be the causative mechanism for neap-spring tidal periods. Gravitational interactions of the earth, moon, and sun generate tides that fluctuate with periods that correspond to the phases of the moon (synodic month), declination of the moon (tropical month), and distance of the moon from the earth (anomalistic month). Although harmonic analyses of semidiurnal tidal data indicate that such systems are controlled by synodic factors, there are also indications that diurnal systems can be controlled by tropical factors. Thus neap-spring periods are not only related to lunar phase (synodic month), but can be related to tropical month (lunar declination) in diurnal systems. Analysis of laminae-thickness periodicities in a variety of Pennsylvanian tidal rhythmites, which include apparent examples of diurnal as well as semidiurnal tidal patterns, indicates similarities to modern tidal systems. For example, semidiurnal tidal rhythmites exhibit not only synodic periodicities but also exhibit a weaker, tropical periodicity. Conversely, within rhythmites that exhibit a diurnal pattern, it is not completely clear whether tropical or synodic periodicities are being expressed.

  9. Tidal exchange between the North Sea and Dutch Wadden Sea and mixing time scales of the tidal basins

    NASA Astrophysics Data System (ADS)

    Ridderinkhof, H.; Zimmerman, J. T. F.; Philippart, M. E.

    Particle trajectories in a numerical model of the western Dutch Wadden Sea and the adjacent North Sea are used to study the tidal exchange between the North Sea and the tidal basins. Tidal exchange of water masses appears to depend strongly on the tidal phase at which the computation is started. In general the volume displaced by the large-scale through-flow between connected tidal basins is much smaller than the exchanged volume. For all inlets North Sea water mainly enters the Wadden Sea from the southern side of the inlet whereas basin water leaves the Wadden Sea mainly along the northern coast. Differences in exchanged volume between the inlets are caused by differences in bathymetry at the seaward side of the different inlets. Schematizing each tidal basin as a single well-mixed box, in which an exchange coefficient parameterizes the exchange with the North Sea, allows a rough estimate of the turnover time of a tidal basin. A salt balance for a simple two-box schematization of the Marsdiep and Vlie basins gives an independent estimate of the exchange coefficient between the Marsdiep basin and the North Sea. Its value appears to be larger than the tidally exchanged volume. The revised salt balance, in which the effect of the through-flow between the Marsdiep and Vlie basins is incorporated, is used to calculate the flushing time of fresh water in the western Dutch Wadden Sea which appears to be larger than previous estimates. The tidally exchanged volume through the inlets, as calculated with the numerical model combined with the relation between the exchange coefficient and the tidally exchanged volume for the Marsdiep basin, is used to give a rough estimate of the turnover time of all Dutch Wadden Sea basins. For the Eierlandse Gat and the Borndiep the exchanged volume is calculated by means of our hydrodynamical model. For the other basins it is assumed that its value is a fixed percentage of the tidal prism entering a basin.

  10. Dissipation of Tidal Energy

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The moon's gravity imparts tremendous energy to the Earth, raising tides throughout the global oceans. What happens to all this energy? This question has been pondered by scientists for over 200 years, and has consequences ranging from the history of the moon to the mixing of the oceans. Richard Ray at NASA's Goddard Space Flight Center, Greenbelt, Md. and Gary Egbert of the College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, Ore. studied six years of altimeter data from the TOPEX/Poseidon satellite to address this question. According to their report in the June 15 issue of Nature, about 1 terawatt, or 25 to 30 percent of the total tidal energy dissipation, occurs in the deep ocean. The remainder occurs in shallow seas, such as on the Patagonian Shelf. 'By measuring sea level with the TOPEX/Poseidon satellite altimeter, our knowledge of the tides in the global ocean has been remarkably improved,' said Richard Ray, a geophysicist at Goddard. The accuracies are now so high that this data can be used to map empirically the tidal energy dissipation. (Red areas, above) The deep-water tidal dissipation occurs generally near rugged bottom topography (seamounts and mid-ocean ridges). 'The observed pattern of deep-ocean dissipation is consistent with topographic scattering of tidal energy into internal motions within the water column, resulting in localized turbulence and mixing', said Gary Egbert an associate professor at OSU. One important implication of this finding concerns the possible energy sources needed to maintain the ocean's large-scale 'conveyor-belt' circulation and to mix upper ocean heat into the abyssal depths. It is thought that 2 terawatts are required for this process. The winds supply about 1 terawatt, and there has been speculation that the tides, by pumping energy into vertical water motions, supply the remainder. However, all current general circulation models of the oceans ignore the tides. 'It is possible that properly

  11. GEE CREEK WILDERNESS, TENNESSEE.

    USGS Publications Warehouse

    Epstein, Jack B.; Gazdik, Gertrude C.

    1984-01-01

    On the basis of geologic, geochemical, and mine and prospect surveys, it was determined that the Gee Creek Wilderness, Tennessee has little promise for the occurrence of mineral resources. Iron ore was formerly mined, but the deposits are small, have a high phosphorous content, and are inaccessible. Shale, suitable for brick or lightweight aggregate, and sandstone, which could be utilized for crushed stone or sand, are found in the area, but are also found in areas closer to potential markets. The geologic setting precludes the presence of oil and gas resources in the surface rocks, but the possibility of finding natural gas at depth below the rocks exposed in the area cannot be discounted. Geophysical exploration would be necessary to define the local structure in rocks at depth to properly evaluate the potential of the area for gas.

  12. Spatial variability of suspended sediment concentration within a tidal marsh in San Francisco Estuary

    NASA Astrophysics Data System (ADS)

    Swanson, K.; Drexler, J. Z.; Schoellhamer, D. H.; Buffington, K.; Takekawa, J.

    2012-12-01

    The sustainability of existing marshes and feasibility of future marsh restoration projects in San Francisco Estuary and elsewhere are threatened by a potential imbalance between accelerating sea-level rise and tidal marsh accretion rates. Marsh accretion is, in large part, dependent upon the availability of suspended sediment supplied from adjacent waterways. As water and sediment move across a marsh plain, suspended sediment settles and is trapped by vegetation near the source, resulting in less suspended-sediment concentration (SSC) and deposition in the interior of the marsh. Measurements of deposition and limited observations of SSC within marshes have confirmed a decrease in sediment supply and accumulation from the marsh edge to the marsh interiors, but the spatial variability of SSC has not been quantified in a manner that allows for comparison to a theoretical sediment transport model. For this study, transects of SSC were collected within a marsh at China Camp State Park in the San Francisco Estuary which demonstrate that a dominant pattern of settling can be quantified and generally matches the exponentially decreasing pattern of SSC predicted by a simple advection-settling model. The observed pattern suggests that sediment settling and marsh flow characteristics are consistent both spatially (between transects) and temporally (between monthly sampling events). However, deviations from the predicted pattern occurred systematically at some locations and are likely related to resuspension of sediment from the marsh surface or small, unmapped creek channels that supply sediment to the marsh. Despite these deviations, our data show this simple 1-D model of advection and settling can be used to generalize within-marsh sediment transport as a function of distance from the nearest sediment source.

  13. Water table fluctuations near an incised stream, Walnut Creek, Iowa

    USGS Publications Warehouse

    Schilling, K.E.; Zhang, Y.-K.; Drobney, P.

    2004-01-01

    Incised channels are common features in many agricultural watersheds, but the effects of channel incision on riparian water table conditions have been poorly documented. In this study, we evaluate the water table fluctuations in the floodplain near an incised stream (Walnut Creek, Iowa) and investigate the roles that channel incision and variable recharge play in modifying the water table configuration in the floodplain. Groundwater flows from higher landscape positions towards Walnut Creek under hydraulic gradients that were steepest near the upland/floodplain contact and in the near-stream riparian zone. Annually, water table fluctuations on the floodplain were greatest in wells located 30 m from the creek, midway between the creek and upland. Water levels monitored continuously during a runoff event indicated that bank storage was confined to a narrow zone adjacent to the channel. A steady-state, one-dimensional analytical model was developed to describe the shape of the water table surface near an incised stream and evaluate how variable groundwater recharge and channel bed lowering has affected the shape of the water table surface. Results from this study have implications for managing the riparian buffers of incised streams with successful establishment dependent upon matching buffer vegetation to riparian water table conditions. ?? 2003 Elsevier B.V. All rights reserved.

  14. Tidal flushing restores the physiological condition of fish residing in degraded salt marshes.

    PubMed

    Dibble, Kimberly L; Meyerson, Laura A

    2012-01-01

    Roads, bridges, and dikes constructed across salt marshes can restrict tidal flow, degrade habitat quality for nekton, and facilitate invasion by non-native plants including Phragmites australis. Introduced P. australis contributes to marsh accretion and eliminates marsh surface pools thereby adversely affecting fish by reducing access to intertidal habitats essential for feeding, reproduction, and refuge. Our study assessed the condition of resident fish populations (Fundulus heteroclitus) at four tidally restricted and four tidally restored marshes in New England invaded by P. australis relative to adjacent reference salt marshes. We used physiological and morphological indicators of fish condition, including proximate body composition (% lipid, % lean dry, % water), recent daily growth rate, age class distributions, parasite prevalence, female gravidity status, length-weight regressions, and a common morphological indicator (Fulton's K) to assess impacts to fish health. We detected a significant increase in the quantity of parasites infecting fish in tidally restricted marshes but not in those where tidal flow was restored to reduce P. australis cover. Using fish length as a covariate, we found that unparasitized, non-gravid F. heteroclitus in tidally restricted marshes had significantly reduced lipid reserves and increased lean dry (structural) mass relative to fish residing in reference marshes. Fish in tidally restored marshes were equivalent across all metrics relative to those in reference marshes indicating that habitat quality was restored via increased tidal flushing. Reference marshes adjacent to tidally restored sites contained the highest abundance of young fish (ages 0-1) while tidally restricted marshes contained the lowest. Results indicate that F. heteroclitus residing in physically and hydrologically altered marshes are at a disadvantage relative to fish in reference marshes but the effects can be reversed through ecological restoration.

  15. Tidal Flushing Restores the Physiological Condition of Fish Residing in Degraded Salt Marshes

    PubMed Central

    Dibble, Kimberly L.; Meyerson, Laura A.

    2012-01-01

    Roads, bridges, and dikes constructed across salt marshes can restrict tidal flow, degrade habitat quality for nekton, and facilitate invasion by non-native plants including Phragmites australis. Introduced P. australis contributes to marsh accretion and eliminates marsh surface pools thereby adversely affecting fish by reducing access to intertidal habitats essential for feeding, reproduction, and refuge. Our study assessed the condition of resident fish populations (Fundulus heteroclitus) at four tidally restricted and four tidally restored marshes in New England invaded by P. australis relative to adjacent reference salt marshes. We used physiological and morphological indicators of fish condition, including proximate body composition (% lipid, % lean dry, % water), recent daily growth rate, age class distributions, parasite prevalence, female gravidity status, length-weight regressions, and a common morphological indicator (Fulton’s K) to assess impacts to fish health. We detected a significant increase in the quantity of parasites infecting fish in tidally restricted marshes but not in those where tidal flow was restored to reduce P. australis cover. Using fish length as a covariate, we found that unparasitized, non-gravid F. heteroclitus in tidally restricted marshes had significantly reduced lipid reserves and increased lean dry (structural) mass relative to fish residing in reference marshes. Fish in tidally restored marshes were equivalent across all metrics relative to those in reference marshes indicating that habitat quality was restored via increased tidal flushing. Reference marshes adjacent to tidally restored sites contained the highest abundance of young fish (ages 0–1) while tidally restricted marshes contained the lowest. Results indicate that F. heteroclitus residing in physically and hydrologically altered marshes are at a disadvantage relative to fish in reference marshes but the effects can be reversed through ecological restoration. PMID

  16. Tidal heating of Ariel

    NASA Technical Reports Server (NTRS)

    Tittemore, William C.

    1990-01-01

    During evolution through the 4:1 commensurability early in the history of the Uranian system, over 3.8 billion years ago, tidal heating may have raised the internal temperature of Ariel by up to about 20 K; the internal temperature of Ariel may already have been high in virtue of both accretional and radiogenic heating. The additional increase in Ariel's temperature could then have triggered the geological activity that led to a late resurfacing, by decreasing lithospheric thickness and exacerbating thermal stresses on it to the point where observed cracks and faults formed.

  17. Conservation of tidal marshes

    SciTech Connect

    Daiber, F.C.

    1986-01-01

    This book is the first attempt to examine collectively the various uses and the consequences of marsh conservation efforts. Author Franklin Daiber emphasizes tidal marsh conservation from a holistic perspective rather than from the perspective of a single purpose or special economic interest. He addresses a topic receiving increasing attention, namely the concept of open marsh management as a means of controlling mosquito production without harmful effects on other marsh organisms. Topics considered include: water management; dikes, impoundments, ponds and ditches; reclaimed land and impoundments; ditching and ponding for mosquito control; sewage disposal and waste treatment; dredge material for wetland restoration; insecticides; oil pollution; and petroleum hydrocarbon interactions.

  18. Tidal Energy Research

    SciTech Connect

    Stelzenmuller, Nickolas; Aliseda, Alberto; Palodichuk, Michael; Polagye, Brian; Thomson, James; Chime, Arshiya; Malte, Philip

    2014-03-31

    This technical report contains results on the following topics: 1) Testing and analysis of sub-scale hydro-kinetic turbines in a flume, including the design and fabrication of the instrumented turbines. 2) Field measurements and analysis of the tidal energy resource and at a site in northern Puget Sound, that is being examined for turbine installation. 3) Conceptual design and performance analysis of hydro-kinetic turbines operating at high blockage ratio, for use for power generation and flow control in open channel flows.

  19. Nekton community structure varies in response to coastal urbanization near mangrove tidal tributaries

    USGS Publications Warehouse

    Krebs, Justin M.; McIvor, Carole C.; Bell, Susan S.

    2014-01-01

    To assess the potential influence of coastal development on estuarine-habitat quality, we characterized land use and the intensity of land development surrounding small tidal tributaries in Tampa Bay. Based on this characterization, we classified tributaries as undeveloped, industrial, urban, or man-made (i.e., mosquito-control ditches). Over one third (37 %) of the tributaries have been heavily developed based on landscape development intensity (LDI) index values >5.0, while fewer than one third (28 %) remain relatively undeveloped (LDI < 3.0). We then examined the nekton community from 11 tributaries in watersheds representing the four defined land-use classes. Whereas mean nekton density was independent of land use, species richness and nekton-community structure were significantly different between urban and non-urban (i.e., undeveloped, industrial, man-made) tributaries. In urban creeks, the community was species-poor and dominated by high densities of poeciliid fishes, Poecilia latipinna and Gambusia holbrooki, while typically dominant estuarine taxa including Menidia spp., Fundulus grandis, and Adinia xenica were in low abundance and palaemonid grass shrimp were nearly absent. Densities of economically important taxa in urban creeks were only half that observed in five of the six undeveloped or industrial creeks, but were similar to those observed in mosquito ditches suggesting that habitat quality in urban and mosquito-ditch tributaries is suboptimal compared to undeveloped tidal creeks. Furthermore, five of nine common taxa were rarely collected in urban creeks. Our results suggest that urban development in coastal areas has the potential to alter the quality of habitat for nekton in small tidal tributaries as reflected by variation in the nekton community.

  20. TIDAL AND TIDALLY AVERAGED CIRCULATION CHARACTERISTICS OF SUISUN BAY, CALIFORNIA.

    USGS Publications Warehouse

    Smith, Lawrence H.; Cheng, Ralph T.

    1987-01-01

    Availability of extensive field data permitted realistic calibration and validation of a hydrodynamic model of tidal circulation and salt transport for Suisun Bay, California. Suisun Bay is a partially mixed embayment of northern San Francisco Bay located just seaward of the Sacramento-San Joaquin Delta. The model employs a variant of an alternating direction implicit finite-difference method to solve the hydrodynamic equations and an Eulerian-Lagrangian method to solve the salt transport equation. An upwind formulation of the advective acceleration terms of the momentum equations was employed to avoid oscillations in the tidally averaged velocity field produced by central spatial differencing of these terms. Simulation results of tidal circulation and salt transport demonstrate that tides and the complex bathymetry determine the patterns of tidal velocities and that net changes in the salinity distribution over a few tidal cycles are small despite large changes during each cycle.

  1. Water quality monitoring report for the White Oak Creek Embayment

    SciTech Connect

    Ford, C.J. ); Wefer, M.T. )

    1993-01-01

    Water quality monitoring activities that focused on the detection of resuspended sediments in the Clinch River were conducted in conjunction with the White Oak Creek Embayment (WOCE) time-critical Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to construct a sediment-retention structure at the mouth of White Oak Creek (WOC). Samples were collected by use of a 24-h composite sampler and through real-time water grab sampling of sediment plumes generated by the construction activities. Sampling stations were established both at the WOC mouth, immediately adjacent to the construction site, and at K-1513, the Oak Ridge K-25 Site drinking water intake approximately 9.6 km downstream in the Clinch River. Results are described.

  2. Parameterization of an Active Thermal Erosion Site, Caribou Creek, Alaska

    NASA Astrophysics Data System (ADS)

    Busey, R.; Bolton, W. R.; Cherry, J. E.; Hinzman, L. D.

    2012-12-01

    Thermokarst features are thought to be an important mechanism for landscape change in permafrost-dominated cold regions, but few such features have been incorporated into full featured landscape models. The root of this shortcoming is that historic observations are not detailed enough to parameterize a model, and the models typically do not include the relevant processes for thermal erosion. A new, dynamic thermokarst feature has been identified at the Caribou-Poker Creek Research Watershed (CPCRW) in the boreal forest of Interior Alaska. Located adjacent to a traditional use trail, this feature terminates directly in Caribou Creek. Erosion within the feature is driven predominantly by fluvial interflow. CPCRW is a Long-Term Ecological Research site underlain by varying degrees of relatively warm, discontinuous permafrost. This poster will describe the suite of measurements that have been undertaken to parameterize the ERODE model for this site, including thorough surveys, time lapse- and aerial photography, and 3-D structure from motion algorithms.

  3. Perspective view of span over French Creek and east abutment, ...

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

    Perspective view of span over French Creek and east abutment, looking NW. - Pennsylvania Railroad, French Creek Trestle, Spanning French Creek, north of Paradise Street, Phoenixville, Chester County, PA

  4. 2. EAGLE CREEK RECREATION AREA, VIEW OF COMMUNITY KITCHEN. ...

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

    2. EAGLE CREEK RECREATION AREA, VIEW OF COMMUNITY KITCHEN. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  5. Tidal Pools--Miniature Oceans

    ERIC Educational Resources Information Center

    Plake, Linda Perry

    1977-01-01

    A comprehensive discussion of the biological activity in tidal pools is provided. The importance of environmental factors such as oxygen supply, temperature, salinity, and light is detailed. Plants and animals that might be found in a tidal pool are identified and described. (BT)

  6. Suppression of tidal conversion by virtual seafloor

    NASA Astrophysics Data System (ADS)

    Swinney, Harry L.; Zhang, Likun

    2014-11-01

    We examine in numerical simulations how the conversion of tidal energy into internal gravity wave energy is suppressed by wave interference between adjacent ridges of steep topography [L.K. Zhang and H.L. Swinney, Phys. Rev. Lett. 112, 104502 (2014)]. Simulations for both periodic and random steep topographies reveal that the time-averaged wave energy radiated upwards arises only from the portion of the ridges above an elevated ``virtual seafloor.'' We find that the average radiated wave power can be predicted by linear theory for weak topography by replacing the actual floor with the virtual floor. The virtual floor concept is used to extend linear theory to predict the energy conversion rate for steep topography. This nonlocal modification of linear theory should be useful in estimating the energy flux generated by tidal flow over the global seafloor. Supported by ONR MURI Grant N000141110701 (WHOI). Also, LZ is supported by the 2013-14 ASA F. V. Hunt Postdoctoral Research Fellowship.

  7. 77 FR 13592 - AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC, Eagle Creek Water Resources, LLC, Eagle Creek Land...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-07

    ... Energy Regulatory Commission AER NY-Gen, LLC; Eagle Creek Hydro Power, LLC, Eagle Creek Water Resources... Power, LLC, Eagle Creek Water Resources, LLC, and Eagle Creek Land Resources, LLC (transferees) filed an...) 805-1469. Transferees: Mr. Bernard H. Cherry, Eagle Creek Hydro Power, LLC, Eagle Creek...

  8. DTP: a Tidal Power Revolution

    NASA Astrophysics Data System (ADS)

    Steijn, Robbert; Hulsbergen, Kees; van Banning, Gijs

    2013-04-01

    Tidal power can significantly contribute to the global mix of sustainable energy resources. It is climate-independent, fully predictable, and if designed properly it is environmentally friendly and socio-economically feasible. The two traditional methods of exploiting tidal power are Tidal Barrage and Tidal Stream. This study deals with an alternative Third Method, named Dynamic Tidal Power (DTP), which contrary to the other methods, utilises the oscillating character of tides, or more precisely: the acceleration inherent to unsteady flow. DTP uses a long dam (order of tens of km's), attached and perpendicular to a coast with shore-parallel tidal currents, to generate a local hydraulic head. This time-varying head is used to generate electricity in a more or less standard way with turbines and generators placed in (many) dam openings. For a first impression only: typical installed power for one DTP is more than 10 GW with electricity output > 2.1010 kWh/y and construction costs of ca. 1 EUR/W. The physical mechanism behind the creation of the head has been described by Hulsbergen e.a., (2012). Following a heuristic approach based on analytical work done by Kolkman (unpubl.), and output from numerical tidal models, Hulsbergen (2012) concluded that the maximum head (near the coast), is: hmax = 6,8*?*D*Vmax/(g*T), with Vmax the maximum alongshore flow velocity during the tidal cycle, T the tidal period and D the length of dam. Such simple relationship was also found by Mei (2012) who made a rigorous analysis of a process-based model. After a thorough reflection on DTP, this study will first check the above formula for hmax , by comparing its predictions with the output from various numerical tidal models. Any differences will be analysed in the study through an evaluation of the dominant physical processes and the schematisations inherent to both the analytical and the numerical models. The study will also address the effect of the openings in the dam, as well as the

  9. Changes in water quality following tidal inundation of coastal lowland acid sulfate soil landscapes

    NASA Astrophysics Data System (ADS)

    Johnston, Scott G.; Bush, Richard T.; Sullivan, Leigh A.; Burton, Edward D.; Smith, Douglas; Martens, Michelle A.; McElnea, Angus E.; Ahern, R., , Col; Powell, Bernard; Stephens, Luisa P.; Wilbraham, Steve T.; van Heel, Simon

    2009-01-01

    This study examines the remediation of surface water quality in a severely degraded coastal acid sulfate soil landscape. The remediation strategy consisted of partial restoration of marine tidal exchange within estuarine creeks and incremental tidal inundation of acidified soils, plus strategic liming of drainage waters. Time-series water quality and climatic data collected over 5 years were analysed to assess changes in water quality due to this remediation strategy. A time-weighted rainfall function (TWR) was generated from daily rainfall data to integrate the effects of antecedent rainfall on shallow groundwater levels in a way that was relevant to acid export dynamics. Significant increases in mean pH were evident over time at multiple monitoring sites. Regression analysis at multiple sites revealed a temporal progression of change in significant relationships between mean daily electrical conductivity (EC) vs. mean daily pH, and TWR vs. mean daily pH. These data demonstrate a substantial decrease over time in the magnitude of creek acidification per given quantity of antecedent rainfall. Data also show considerable increase in soil pH (2-3 units) in formerly acidified areas subject to tidal inundation. This coincides with a decrease in soil pe, indicating stronger reducing conditions. These observations suggest a fundamental shift has occurred in sediment geochemistry in favour of proton-consuming reductive processes. Combined, these data highlight the potential effectiveness of marine tidal inundation as a landscape-scale acid sulfate soil remediation strategy.

  10. Big Bayou Creek and Little Bayou Creek Watershed Monitoring Program

    SciTech Connect

    Kszos, L.A.; Peterson, M.J.; Ryon; Smith, J.G.

    1999-03-01

    Biological monitoring of Little Bayou and Big Bayou creeks, which border the Paducah Site, has been conducted since 1987. Biological monitoring was conducted by University of Kentucky from 1987 to 1991 and by staff of the Environmental Sciences Division (ESD) at Oak Ridge National Laboratory (ORNL) from 1991 through March 1999. In March 1998, renewed Kentucky Pollutant Discharge Elimination System (KPDES) permits were issued to the US Department of Energy (DOE) and US Enrichment Corporation. The renewed DOE permit requires that a watershed monitoring program be developed for the Paducah Site within 90 days of the effective date of the renewed permit. This plan outlines the sampling and analysis that will be conducted for the watershed monitoring program. The objectives of the watershed monitoring are to (1) determine whether discharges from the Paducah Site and the Solid Waste Management Units (SWMUs) associated with the Paducah Site are adversely affecting instream fauna, (2) assess the ecological health of Little Bayou and Big Bayou creeks, (3) assess the degree to which abatement actions ecologically benefit Big Bayou Creek and Little Bayou Creek, (4) provide guidance for remediation, (5) provide an evaluation of changes in potential human health concerns, and (6) provide data which could be used to assess the impact of inadvertent spills or fish kill. According to the cleanup will result in these watersheds [Big Bayou and Little Bayou creeks] achieving compliance with the applicable water quality criteria.

  11. Tidal Venuses: Triggering a Climate Catastrophe via Tidal Heating

    PubMed Central

    Mullins, Kristina; Goldblatt, Colin; Meadows, Victoria S.; Kasting, James F.; Heller, René

    2013-01-01

    Abstract Traditionally, stellar radiation has been the only heat source considered capable of determining global climate on long timescales. Here, we show that terrestrial exoplanets orbiting low-mass stars may be tidally heated at high-enough levels to induce a runaway greenhouse for a long-enough duration for all the hydrogen to escape. Without hydrogen, the planet no longer has water and cannot support life. We call these planets “Tidal Venuses” and the phenomenon a “tidal greenhouse.” Tidal effects also circularize the orbit, which decreases tidal heating. Hence, some planets may form with large eccentricity, with its accompanying large tidal heating, and lose their water, but eventually settle into nearly circular orbits (i.e., with negligible tidal heating) in the habitable zone (HZ). However, these planets are not habitable, as past tidal heating desiccated them, and hence should not be ranked highly for detailed follow-up observations aimed at detecting biosignatures. We simulated the evolution of hypothetical planetary systems in a quasi-continuous parameter distribution and found that we could constrain the history of the system by statistical arguments. Planets orbiting stars with masses<0.3 MSun may be in danger of desiccation via tidal heating. We have applied these concepts to Gl 667C c, a ∼4.5 MEarth planet orbiting a 0.3 MSun star at 0.12 AU. We found that it probably did not lose its water via tidal heating, as orbital stability is unlikely for the high eccentricities required for the tidal greenhouse. As the inner edge of the HZ is defined by the onset of a runaway or moist greenhouse powered by radiation, our results represent a fundamental revision to the HZ for noncircular orbits. In the appendices we review (a) the moist and runaway greenhouses, (b) hydrogen escape, (c) stellar mass-radius and mass-luminosity relations, (d) terrestrial planet mass-radius relations, and (e) linear tidal theories. Key Words: Extrasolar terrestrial

  12. Galileo's tidal theory.

    PubMed

    Naylor, Ron

    2007-03-01

    The aim of Galileo's tidal theory was to show that the tides were produced entirely by the earth's motion and thereby to demonstrate the physical truth of Copernicanism. However, in the Dialogue Concerning the Two Chief World Systems Galileo did not explain some of the most significant aspects of the theory completely. As a consequence, the way the theory works has long been disputed. Though there exist a number of interpretations in the literature, the most widely accepted are based on ideas that are not explicitly articulated by Galileo in the Dialogue. This essay attempts to understand the way the theory functions in terms of Galilean physics. It is an interpretation of the theory based solely on Galileo's arguments--and one that reveals it to have had some unrecognized consequences. This interpretation indicates that Galileo's theory would not have worked in the manner he described in the Dialogue. PMID:17539198

  13. Galileo's tidal theory.

    PubMed

    Naylor, Ron

    2007-03-01

    The aim of Galileo's tidal theory was to show that the tides were produced entirely by the earth's motion and thereby to demonstrate the physical truth of Copernicanism. However, in the Dialogue Concerning the Two Chief World Systems Galileo did not explain some of the most significant aspects of the theory completely. As a consequence, the way the theory works has long been disputed. Though there exist a number of interpretations in the literature, the most widely accepted are based on ideas that are not explicitly articulated by Galileo in the Dialogue. This essay attempts to understand the way the theory functions in terms of Galilean physics. It is an interpretation of the theory based solely on Galileo's arguments--and one that reveals it to have had some unrecognized consequences. This interpretation indicates that Galileo's theory would not have worked in the manner he described in the Dialogue.

  14. Water Conservation Study for Manastash Creek Water Users, Kittias County, Washington, Final Report 2002.

    SciTech Connect

    Montgomery Watson Harza

    2002-12-31

    Manastash Creek is tributary of the Yakima River and is located southwest and across the Yakima River from the City of Ellensburg. The creek drains mountainous terrain that ranges in elevation from 2,000 feet to over 5,500 feet and is primarily snowmelt fed, with largest flows occurring in spring and early summer. The creek flows through a narrow canyon until reaching a large, open plain that slopes gently toward the Yakima River and enters the main stem of the Yakima River at river mile 154.5. This area, formed by the alluvial fan of the Creek as it leaves the canyon, is the subject of this study. The area is presently dominated by irrigated agriculture, but development pressures are evident as Ellensburg grows and develops as an urban center. Since the mid to late nineteenth century when irrigated agriculture was established in a significant manner in the Yakima River Basin, Manastash Creek has been used to supply irrigation water for farming in the area. Adjudicated water rights dating back to 1871 for 4,465 acres adjacent to Manastash Creek allow appropriation of up to 26,273 acre-feet of creek water for agricultural irrigation and stock water. The diversion of water from Manastash Creek for irrigation has created two main problems for fisheries. They are low flows or dewatered reaches of Manastash Creek and fish passage barriers at the irrigation diversion dams. The primary goal of this study, as expressed by Yakama Nation and BPA, is to reestablish safe access in tributaries of the Yakima River by removing physical barriers and unscreened diversions and by adding instream flow where needed for fisheries. The goal expressed by irrigators who would be affected by these projects is to support sustainable and profitable agricultural use of land that currently uses Manastash Creek water for irrigation. This study provides preliminary costs and recommendations for a range of alternative projects that will partially or fully meet the goal of establishing safe access

  15. Five years (2000-2004) of post-reconstruction monitoring of freshwater tidal wetlands in the urban Anacostia River, Washington, D.C. USA

    USGS Publications Warehouse

    Hammerschlag, D.; Krafft, C.

    2006-01-01

    The Anacostia River in Washington, D.C. USA consisted of over 809 hectares (2000 acres) of freshwater tidal wetlands before mandatory dredging removed most of them in the first half of the 20th century. Much of this13 kilometer (8 mile) reach was transferred to the National Park Service (NPS). Planning processes in the 1980's envisioned a restoration (rejuvenation) of some wetlands for habitat, aesthetics, water quality and interpretative purposes. Subsequently, the U.S. Army Corps of Engineers in a cost share agreement with the District of Columbia reconstructed wetlands on NPS lands at Kenilworth - 12.5 hectares (1993), Kingman 27 hectares (2000), a Fringe Marsh - 6.5 hectares (2003) and is currently constructing Heritage Marsh - 2.5 hectares (2005/2006). The USGS Patuxent Wildlife Research Center in conjunction with the University of Maryland Biological Engineering Department was contracted to conduct post-reconstruction monitoring (2000-2004) to document the relative success and progress of the Kingman Marsh reconstruction primarily based on vegetative response but also in conjunction with seed bank and soil characteristics. Results from Kingman were compared to Kenilworth Marsh (reconstructed 7 years prior), Dueling Creek Marsh (last best remaining freshwater tidal wetland bench in the urbanized Anacostia watershed) and Patuxent River Marsh (in a more natural adjacent watershed). Vegetation establishment was initially strong at Kingman, but declined rapidly as measured by cover, richness, diversity, etc. under grazing pressure from resident Canada geese and associated reduction in sediment levels. This decline did not occur at the other wetlands. The decline occurred despite a substantial seed bank that was sustained primarily be water born propagules. Soil development, as true for most juvenile wetlands, was slow with almost no organic matter accumulation. By 2004 only two of 7 planted species remained (mostly Peltandra virginica) at Kingman which did provide

  16. Tidal influence within Pennsylvanian sandstones

    SciTech Connect

    Archer, A.W. )

    1991-08-01

    Within Pennsylvanian-age strata of the Illinois basin, large-scale linear sand bodies have been previously interpreted as fluvial and deltaic in origin. Nonetheless, analyses of fine-scale sedimentology and bed forms within such sandstones and the associated shales indicate that tidal processes greatly influenced the depositional environments within such lithofacies. Recent work on Mid-Continent Pennsylvanian-age sandstones indicates the occurrence of similar depositional environments. Based upon the pervasive tidal influence observed within such strata, environmental analogs other than fluvial and deltaic bear consideration. In general, tidally influenced estuarine models seem particularly appropriate. Within such settings, the changeover from a fluvially dominated deposystem to tidally influenced estuary occurs during transgressive phases. Despite the tidal influence that can be interpreted from the sedimentology, the strata contain few, if any, marine indicators because of the low salinities that occurred during deposition. Ongoing work in the Mid-Continent indicates that Morrowan, Atokan, Desmoinesian, Missourian, and Virgilian sands share a number of similarities with the tidally influenced environments delineated in the Illinois basin studies. Thus a tidal/estuarine interpretation might be a generalizable model for many Pennsylvanian sandstones. In addition, enhanced understanding of the siliciclastic parts of Mid-Continent cyclothems provides a more useful framework for documentation of carbonate/siliciclastic interrelationships. Oscillations of carbonate/siliciclastic environments may be more readily explainable by climatic cycles rather than by traditionally popular depth-related facies models.

  17. Tidal amplification of seabed light

    NASA Astrophysics Data System (ADS)

    Bowers, D. G.; Brubaker, J. M.

    2010-09-01

    Because solar irradiance decreases approximately exponentially with depth in the sea, the increase in irradiance at the seabed from mid to low tide is greater than the decrease from mid to high tide. Summed over a day, this can lead to a net amplification of seabed irradiance in tidal waters compared to nontidal waters with the same mean depth and transparency. In this paper, this effect is quantified by numerical and analytical integration of the Lambert-Beer equation to derive the ratio of daily total seabed irradiance with and without a tide. Greatest amplification occurs in turbid water with large tidal range and low tide occurring at noon. The theoretical prediction is tested against observations of seabed irradiance in the coastal waters of North Wales where tidal amplification of seabed light by up to a factor of 7 is both observed and predicted. Increasing the strength of tidal currents tends to increase the turbidity of the water and hence reduce the light reaching the seabed, but this effect is made less by increasing tidal amplification, especially when low water is in the middle of the day. The ecological implications of tidal amplification are discussed. The productivity of benthic algae will be greater than that predicted by simple models which calculate seabed irradiance using the mean depth of water alone. Benthic algae are also able to live at greater depths in tidal waters than in nontidal waters with the same transparency.

  18. Geo-morphological changes of the Wanpingkou tidal system arising from the building of a sailing boat station in Rizhao of China.

    PubMed

    Bian, Shuhua; Zhang, Yuanzhi; Feng, Aiping; Chiu, Long; Wu, Sangyun; Hu, Zejian

    2008-03-01

    This paper examines a small tidal system in Wanpingkou, Rizhao of China. The tidal system was originally maintained by a balance of the natural interaction between tidal currents and waves. But this tidal system was diminishing by reclamation processes since the 1980s, especially in 2003 when a sailing boat station was built in the study area. To investigate the stability and development mechanism of the tidal system, its feasibility was evaluated before the sailing boat station was built. The erosion and deposition in and out of the tidal system was analyzed, forecasted and compared with the data from field monitoring. The results show that the tidal system would remain relatively stable, although its adjacent shoreline might change somewhat after the newly built sailing boat station. This change would also affect the coastal water and wetland environment in the study area. Further field monitoring in the area is still necessary.

  19. 5. EAGLE CREEK RECREATION AREA, EXTERIOR VIEW OF PORTION OF ...

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

    5. EAGLE CREEK RECREATION AREA, EXTERIOR VIEW OF PORTION OF EAGLE CREEK OVERLOOK. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  20. 6. EAGLE CREEK RECREATION AREA, INTERIOR VIEW OF PORTION OF ...

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

    6. EAGLE CREEK RECREATION AREA, INTERIOR VIEW OF PORTION OF EAGLE CREEK OVERLOOK. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  1. Tidal dunes versus tidal bars: The sedimentological and architectural characteristics of compound dunes in a tidal seaway, the lower Baronia Sandstone (Lower Eocene), Ager Basin, Spain

    NASA Astrophysics Data System (ADS)

    Olariu, Cornel; Steel, Ronald J.; Dalrymple, Robert W.; Gingras, Murray K.

    2012-11-01

    The Lower Eocene Baronia Formation in the Ager Basin is interpreted as a series of stacked compound dunes confined within a tectonically generated embayment or tidal seaway. This differs from the previous interpretation of lower Baronia sand bodies as tidal bars in the front of a delta. The key architectural building block of the succession, the deposit of a single compound dune, forms a 1-3 m-thick, upward coarsening succession that begins with highly bioturbated, muddy, very fine to fine grained sandstone that contains an open-marine Cruziana ichnofacies. This is overlain gradationally by ripple-laminated sandstone that is commonly bioturbated and contains mud drapes. The succession is capped by fine- to coarse-grained sandstones that contain both planar and trough cross-strata with unidirectional or bi-directional paleocurrent directions and occasional thin mud drapes on the foresets. The base of a compound dune is gradational where it migrated over muddy sandstone deposited between adjacent dunes, but is sharp and erosional where it migrated over the stoss side of a previous compound dune. The cross strata that formed by simple superimposed dunes dip in the same direction as the inclined master bedding planes within the compound dune, forming a forward-accretion architecture. This configuration is the fundamental reason why these sandbodies are interpreted as compound tidal dunes rather than as tidal bars, which, in contrast, generate lateral-accretion architecture. In the Baronia, fields of compound dunes generated tabular sandbodies 100s to 1000s of meters in extent parallel to the paleocurrent direction and up to 6 m thick that alternate vertically with highly bioturbated muddy sandstones (up to 10 m thick) that represent the low-energy fringes of the dune fields or periods of high sea level when current speeds decreased. Each cross-stratified sandstone sheet (compound-dune complexes) contains overlapping lenticular "shingles" formed by individual compound

  2. Tidal circulation alteration for salt marsh mosquito control

    NASA Astrophysics Data System (ADS)

    Resh, Vincent H.; Balling, Steven S.

    1983-01-01

    Mosquito control ditches designed to increase tidal circulation are widely used as a physical control alternative to insecticidal applications The impact of such ditching on Pacific Coast marshlands was largely unknown before this five-year study of impact in two types of San Francisco Bay salt marshes, a Salicornia virginica (pickleweed) monoculure and a mixed vegetation marsh Results of our studies suggest that ditches cause less environmental disturbance than insecticidal applications The article describes the following environmental consequences of ditching for mosquito control: increased tidal flushing of soils occurs adjacent to ditches compared with that in the open marsh, thereby reducing ground water and soil surface salinities and water table height; primary productivity of S. virginica, as determined by both the harvest method and infrared photographic analysis, is higher directly adjacent to ditches than in the open marsh, distribution of selected arthropod populations is similar at ditches and natural channels, although arthropod community response differs seasonally; aquatic invertebrate biomass is similar within ditched and natural ponds, but diversity is lower in ditched habitats, ditching increases fish diversity and density by improving fish access from tidal channels; ditches provide additional salt marsh song sparrow habitat, although ditches are less preferred than natural channels or sloughs. Management criteria can be used to design ditches that provide effective mosquito control and reduced environmental impact

  3. Development and morphology of point bars in tidal rivers, observations from Sapelo and the Altamaha River, GA

    NASA Astrophysics Data System (ADS)

    Hughes, Z. J.; Georgiou, I. Y.; Howes, N. C.; Weathers, D.; Kulp, M.; FitzGerald, D. M.

    2012-12-01

    Many tidal creeks and rivers exhibit bars associated with meander bends. However, hydrodynamic and morphodynamic studies of these point-bars are scarce, compared with the extensive studies of fluvial-point bars. The few studies that have been undertaken suggest significant differences between tidal bars and their fluvial counterparts, including low rates of channel migration, a unique planform morphology resulting from the bi-directional tidal flows and tidal asymmetry, and variation in stage-discharge behavior. We examine point-bars in two closely situated estuaries on the Georgia coast: the Altamaha and Sapelo. Both sites are meso-tidal; however, the Altamaha has significant fluvial input, whereas the Sapelo creeks have minimal fluvial input. Both sites exhibit mixed sand-mud point bars of various sizes. However, sites dominated by fluvial processes are coarser-grained and contain a higher percentage of sand. Velocity measurements from vessel-mounted and moored acoustic Doppler current profilers record the separation of flood and ebb flows to either side of the tidal bars, which results in a residual circulation over their surface. Large bedforms with opposing migration directions are observed on either side of the bar, suggesting that each side of the channel experiences a separate sediment transport regime. Shallow seismic data at two resolutions (Boomer and Chirp) indicate that the internal architecture of the tidal bars consists of lateral accretion surfaces with multi-directional strike orientations and dips, suggesting a more complex pattern of growth and development. We compare and contrast the hydrodynamics and the resulting morphologies of the bars and identify differences between fluvially-influenced and purely tidal environments. This data set also allows us to examine the hypothesis that these forms are scale invariant by examining a wide range of bars in both large and small channels.

  4. Spatial variability in denitrification rates in an Oregon tidal salt marsh

    EPA Science Inventory

    Modeling denitrification (DeN) is particularly challenging in tidal systems, which play a vital role in buffering adjacent coastal waters from nitrogen inputs. These systems are hydrologically and biogeochemically complex, varying on fine temporal and spatial scales. As part of a...

  5. Water quality study at the Congaree Swamp National monument of Myers Creek, Reeves Creek and Toms Creek. Technical report

    SciTech Connect

    Rikard, M.

    1991-11-01

    The Congaree Swamp National Monument is one of the last significant near virgin tracts of bottom land hardwood forests in the Southeast United States. The study documents a water quality monitoring program on Myers Creek, Reeves Creek and Toms Creek. Basic water quality parameters were analyzed. High levels of aluminum and iron were found, and recommendations were made for further monitoring.

  6. Asotin Creek Model Watershed Plan

    SciTech Connect

    Browne, D.; Holzmiller, J.; Koch, F.; Polumsky, S.; Schlee, D.; Thiessen, G.; Johnson, C.

    1995-04-01

    The Asotin Creek Model Watershed Plan is the first to be developed in Washington State which is specifically concerned with habitat protection and restoration for salmon and trout. The plan is consistent with the habitat element of the ``Strategy for Salmon``. Asotin Creek is similar in many ways to other salmon-bearing streams in the Snake River system. Its watershed has been significantly impacted by human activities and catastrophic natural events, such as floods and droughts. It supports only remnant salmon and trout populations compared to earlier years. It will require protection and restoration of its fish habitat and riparian corridor in order to increase its salmonid productivity. The watershed coordinator for the Asotin County Conservation District led a locally based process that combined local concerns and knowledge with technology from several agencies to produce the Asotin Creek Model Watershed Plan.

  7. Enceladus' tidal dissipation revisited

    NASA Astrophysics Data System (ADS)

    Tobie, Gabriel; Behounkova, Marie; Choblet, Gael; Cadek, Ondrej; Soucek, Ondrej

    2016-10-01

    A series of chemical and physical evidence indicates that the intense activity at Enceladus' South Pole is related to a subsurface salty water reservoir underneath the tectonically active ice shell. The detection of a significant libration implies that this water reservoir is global and that the average ice shell thickness is about 20-25km (Thomas et al. 2016). The interpretation of gravity and topography data further predicts large variations in ice shell thickness, resulting in a shell potentially thinner than 5 km in the South Polar Terrain (SPT) (Cadek et al. 2016). Such an ice shell structure requires a very strong heat source in the interior, with a focusing mechanism at the SPT. Thermal diffusion through the ice shell implies that at least 25-30 GW is lost into space by passive diffusion, implying a very efficient dissipation mechanism in Enceladus' interior to maintain such an ocean/ice configuration thermally stable.In order to determine in which conditions such a large dissipation power may be generated, we model the tidal response of Enceladus including variable ice shell thickness. For the rock core, we consider a wide range of rheological parameters representative of water-saturated porous rock materials. We demonstrate that the thinning toward the South Pole leads to a strong increase in heat production in the ice shell, with a optimal thickness obtained between 1.5 and 3 km, depending on the assumed ice viscosity. Our results imply that the heat production in the ice shell within the SPT may be sufficient to counterbalance the heat loss by diffusion and to power eruption activity. However, outside the SPT, a strong dissipation in the porous core is required to counterbalance the diffusive heat loss. We show that about 20 GW can be generated in the core, for an effective viscosity of 1012 Pa.s, which is comparable to the effective viscosity estimated in water-saturated glacial tills on Earth. We will discuss the implications of this revisited tidal

  8. Tidal day organic and inorganic material flux of ponds in the Liberty Island freshwater tidal wetland.

    PubMed

    Lehman, Peggy W; Mayr, Shawn; Liu, Leji; Tang, Alison

    2015-01-01

    The loss of inorganic and organic material export and habitat produced by freshwater tidal wetlands is hypothesized to be an important contributing factor to the long-term decline in fishery production in San Francisco Estuary. However, due to the absence of freshwater tidal wetlands in the estuary, there is little information on the export of inorganic and organic carbon, nutrient or phytoplankton community biomass and the associated mechanisms. A single-day study was conducted to assess the potential contribution of two small vegetated ponds and one large open-water pond to the inorganic and organic material flux within the freshwater tidal wetland Liberty Island in San Francisco Estuary. The study consisted of an intensive tidal day (25.5 h) sampling program that measured the flux of inorganic and organic material at three ponds using continuous monitoring of flow, chlorophyll a, turbidity and salt combined with discrete measurements of phytoplankton community carbon, total and dissolved organic carbon and nutrient concentration at 1.5 h intervals. Vegetated ponds had greater material concentrations than the open water pond and, despite their small area, contributed up to 81% of the organic and 61% of the inorganic material flux of the wetland. Exchange between ponds was important to wetland flux. The small vegetated pond in the interior of the wetland contributed as much as 72-87% of the total organic carbon and chlorophyll a and 10% of the diatom flux of the wetland. Export of inorganic and organic material from the small vegetated ponds was facilitated by small-scale topography and tidal asymmetry that produced a 40% greater material export on ebb tide. The small vegetated ponds contrasted with the large open water pond, which imported 29-96% of the inorganic and 4-81% of the organic material into the wetland from the adjacent river. This study identified small vegetated ponds as an important source of inorganic and organic material to the wetland and the

  9. Effect of subseabed salt domes on Tidal Residual currents in the Persian Gulf

    NASA Astrophysics Data System (ADS)

    Mashayekh Poul, Hossein; Backhaus, Jan; Dehghani, Ali; Huebner, Udo

    2016-05-01

    Geological studies in the Persian Gulf (PG) have revealed the existence of subseabed salt-domes. With suitable filtering of a high-resolution PG seabed topography, it is seen that the domes leave their signature in the seabed, i.e., numerous hills and valleys with amplitudes of several tens of meters and radii from a few up to tens of kilometers. It was suspected that the "shark skin" of the PG seabed may affect the tidal residual flow. The interaction of tidal dynamics and these obstacles was investigated in a nonlinear hydrodynamic numerical tidal model of the PG. The model was first used to characterize flow patterns of residual currents generated by a tidal wave passing over symmetric, elongated and tilted obstacles. Thereafter it was applied to the entire PG. The model was forced at its open boundary by the four dominant tidal constituents residing in the PG. Each tidal constituent was simulated separately. Results, i.e., tidal residual currents in the PG, as depicted by Lagrangian trajectories reveal a stationary flow that is very rich in eddies. Each eddy can be identified with a topographic obstacle. This confirms that the tidal residual flow field is strongly influenced by the nonlinear interaction of the tidal wave with the bottom relief which, in turn, is deformed by salt-domes beneath the seabed. Different areas of maximum residual current velocities are identified for major tidal constituents. The pattern of trajectories indicates the presence of two main cyclonic gyres and several adjacent gyres rotating in opposite directions and a strong coastal current in the northern PG.

  10. Resurgence of submersed aquatic macrophytes in the tidal Potomac River, Maryland, Virginia, and the District of Columbia

    USGS Publications Warehouse

    Carter, V.; Rybicki, N.

    1986-01-01

    A 1978-81 survey of submersed aquatic macrophytes in the tidal Potomac River showed that there were virtually no plants in the freshwater tidal river between Chain Bridge and Quantico, Virginia, decades after the disappearance of plants in the late 1930's. Plant populations were monitored in subsequent years (1983-85) using qualitative shoreline surveys and quantitative resampling of the original 1978-81 transects. In 1983, 12 species of submersed aquatic macrophytes were found in the tidal river. Population increases were dramatic; by fall 1985, plants had colonized all shallow areas between Alexandria and Gunston Cove, Virginia. Hydrilla verticillata dominated in Dyke Marsh-Hunting Creek and Swan Creek. Most other areas contained a variable mixture of Heteranthera dubia, Myriophyllum spicatum, Ceratophyllum demersum, Vallisneria americana, Najas guadalupensis and Hydrilla verticillata. No plants were found along the main river or in tidal embayments in the reach between Gunston Cove and Quantico, Virginia. Total dry weight collected in the upper tidal river in fall 1985 was 14.5 times that of spring 1985, and four times that of fall 1984. ?? 1986 Estuarine Research Federation.

  11. 27 CFR 9.62 - Loramie Creek.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.62 Loramie Creek. (a) Name. The name of the viticultural area described in this section is “Loramie Creek.” (b) Approved map. The approved map for the Loramie Creek viticultural area is the U.S.G.S....

  12. 27 CFR 9.62 - Loramie Creek.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.62 Loramie Creek. (a) Name. The name of the viticultural area described in this section is “Loramie Creek.” (b) Approved map. The approved map for the Loramie Creek viticultural area is the U.S.G.S....

  13. 27 CFR 9.62 - Loramie Creek.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... OF THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.62 Loramie Creek. (a) Name. The name of the viticultural area described in this section is “Loramie Creek.” (b) Approved map. The approved map for the Loramie Creek viticultural area is the U.S.G.S....

  14. 27 CFR 9.62 - Loramie Creek.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.62 Loramie Creek. (a) Name. The name of the viticultural area described in this section is “Loramie Creek.” (b) Approved map. The approved map for the Loramie Creek viticultural area is the U.S.G.S....

  15. 27 CFR 9.62 - Loramie Creek.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.62 Loramie Creek. (a) Name. The name of the viticultural area described in this section is “Loramie Creek.” (b) Approved map. The approved map for the Loramie Creek viticultural area is the U.S.G.S....

  16. Contrasting rainfall generated debris flows from adjacent watersheds at Forest Falls, southern California, USA

    USGS Publications Warehouse

    Morton, D.M.; Alvarez, R.M.; Ruppert, K.R.; Goforth, B.

    2008-01-01

    Debris flows are widespread and common in many steeply sloping areas of southern California. The San Bernardino Mountains community of Forest Falls is probably subject to the most frequently documented debris flows in southern California. Debris flows at Forest Falls are generated during short-duration high-intensity rains that mobilize surface material. Except for debris flows on two consecutive days in November 1965, all the documented historic debris flows have occurred during high-intensity summer rainfall, locally referred to as 'monsoon' or 'cloudburst' rains. Velocities of the moving debris range from about 5??km/h to about 90??km/h. Velocity of a moving flow appears to be essentially a function of the water content of the flow. Low velocity debris flows are characterized by steep snouts that, when stopped, have only small amounts of water draining from the flow. In marked contrast are high-velocity debris flows whose deposits more resemble fluvial deposits. In the Forest Falls area two adjacent drainage basins, Snow Creek and Rattlesnake Creek, have considerably different histories of debris flows. Snow Creek basin, with an area about three times as large as Rattlesnake Creek basin, has a well developed debris flow channel with broad levees. Most of the debris flows in Snow Creek have greater water content and attain higher velocities than those of Rattlesnake Creek. Most debris flows are in relative equilibrium with the geometry of the channel morphology. Exceptionally high-velocity flows, however, overshoot the channel walls at particularly tight channel curves. After overshooting the channel, the flows degrade the adjacent levee surface and remove trees and structures in the immediate path, before spreading out with decreasing velocity. As the velocity decreases the clasts in the debris flows pulverize the up-slope side of the trees and often imbed clasts in them. Debris flows in Rattlesnake Creek are relatively slow moving and commonly stop in the

  17. Land claim and loss of tidal flats in the Yangtze Estuary

    NASA Astrophysics Data System (ADS)

    Chen, Ying; Dong, Jinwei; Xiao, Xiangming; Zhang, Min; Tian, Bo; Zhou, Yunxuan; Li, Bo; Ma, Zhijun

    2016-04-01

    Tidal flats play a critical role in supporting biodiversity and in providing ecosystem services but are rapidly disappearing because of human activities. The Yangtze Estuary is one of the world’s largest alluvial estuaries and is adjacent to the most developed economic zone in China. Using the Yangtze Estuary as a study region, we developed an automatic algorithm to estimate tidal flat areas based on the Land Surface Water Index and the Normalized Difference Vegetation Index. The total area of tidal flats in the Yangtze Estuary has decreased by 36% over the past three decades, including a 38% reduction in saltmarshes and a 31% reduction in barren mudflats. Meanwhile, land claim has accumulated to 1077 km2, a value that exceeds the area of the remaining tidal flats. We divided the Yangtze Estuary into Shanghai and Jiangsu areas, which differ in riverine sediment supply and tidal flat management patterns. Although land claim has accelerated in both areas, the decline in tidal flat area has been much greater in Jiangsu than in Shanghai because of abundant supplies of sediment and artificial siltation in the latter area. The results highlight the need for better coastal planning and management based on tidal flat dynamics.

  18. Land claim and loss of tidal flats in the Yangtze Estuary

    PubMed Central

    Chen, Ying; Dong, Jinwei; Xiao, Xiangming; Zhang, Min; Tian, Bo; Zhou, Yunxuan; Li, Bo; Ma, Zhijun

    2016-01-01

    Tidal flats play a critical role in supporting biodiversity and in providing ecosystem services but are rapidly disappearing because of human activities. The Yangtze Estuary is one of the world’s largest alluvial estuaries and is adjacent to the most developed economic zone in China. Using the Yangtze Estuary as a study region, we developed an automatic algorithm to estimate tidal flat areas based on the Land Surface Water Index and the Normalized Difference Vegetation Index. The total area of tidal flats in the Yangtze Estuary has decreased by 36% over the past three decades, including a 38% reduction in saltmarshes and a 31% reduction in barren mudflats. Meanwhile, land claim has accumulated to 1077 km2, a value that exceeds the area of the remaining tidal flats. We divided the Yangtze Estuary into Shanghai and Jiangsu areas, which differ in riverine sediment supply and tidal flat management patterns. Although land claim has accelerated in both areas, the decline in tidal flat area has been much greater in Jiangsu than in Shanghai because of abundant supplies of sediment and artificial siltation in the latter area. The results highlight the need for better coastal planning and management based on tidal flat dynamics. PMID:27035525

  19. Geomorphic Function and Restoration Potential of Spring Creeks in Southeastern Idaho: Analysis and Communication

    NASA Astrophysics Data System (ADS)

    Hanrahan, T. P.; Hill, Z.; Levell, A.; Maguire, T.; Risso, D.

    2014-12-01

    A large wetland and floodplain complex adjacent to the Snake River in southeastern Idaho, USA, encompasses numerous spring-fed creeks that originate on the floodplain and discharge at their confluence with the Snake River and American Falls Reservoir. Resource managers are implementing a program to restore these spring creeks for the recovery of Yellowstone cutthroat trout and ecosystem health. Our objectives were to evaluate the physical characteristics of these spring creeks, develop a conceptual model of their geomorphic function, compare the restoration potential of individual reaches, and communicate our findings to a broad audience of resource managers and regional stakeholders in order to foster restoration planning. A geomorphic assessment along 38 km of three spring creeks was completed by collecting data at several transects within distinct geomorphic reaches, and by collecting data continuously throughout all reaches. These data were summarized in a GIS database and used to quantify the overall geomorphic functioning of each reach. The geomorphic functional scores were scaled from 0% (non-functional) to 100% (fully functional). Among all three spring creeks, geomorphic function ranged from 29% to 63%, with bank conditions and riparian vegetation being the primary causes of overall channel degradation. Results from the geomorphic assessment fostered the development of a conceptual model for spring creek function, whereby degraded bank conditions represent the primary controlling factor of decreased geomorphic function and fish habitat quality. The reach-based geomorphic functional scoring provides an indicator of relative restoration potential for each reach, and is one of the factors used in determining site-specific priorities for protecting, enhancing, and restoring spring creeks on the Fort Hall Bottoms. The study results, conceptual model and restoration strategy were communicated to resource managers and regional stakeholders through a graphically

  20. Dynamics of arsenic in the mining sites of Pine Creek Geosyncline, Northern Australia.

    PubMed

    Eapaea, Miro Peter; Parry, David; Noller, Barry

    2007-07-01

    The transportation and fixation of arsenic (As) in soil and sediments from five mine sites within the Pine Creek Geosyncline, Northern Territory, were examined based on measurements of operationally-defined fractions of As in soils, sediment and evaporates. Arsenic was mainly retained in sediments in the form iron arsenate (Fe-As). In wetland systems, As was retained as Fe-As together with calcium arsenate (Ca-As) from alkaline groundwater and organic-bound As from detrital material. In retention ponds As was retained as Fe-As, Ca-As and residual As (Res-As) up to 1700 mg/kg. Sediment traps can retain As from alkaline and acidic source seepages. The retention of Res-As and other mineral particulates during erosional or controlled process water discharges was associated with high Fe-As and organic-bound As in sediment. Arsenic was retained as Fe-As, Ca-As and residual As in 100 year old tailings at Millar's Battery, Union Reefs mine nearby McKinlay River and the small copper mine lease MLN 95 adjacent Copperfield Creek nearby Pine Creek. Natural geo-mobilisation of As was observed in upstream sediments at Copperfield Creek (5-8 mg/kg), Mt. Bundey Creek (10-12 mg/kg), upstream Ryan's Creek (10-12 mg/kg) and downstream East branch Ryan's Creek (7 mg/kg). Erosion of As-containing mineralisation was observed in the McKinlay River upstream and downstream (23-26 mg/kg) and upstream Ryan's Creek boundary of the Goodall mine lease MLN 1049 (24-40 mg/kg). Overall, As was mainly retained in sediments in the form Fe-As. The concentration data for As were used to propose mechanisms of As dispersion and retention occurring at the various mine sites that can be utilised for future mine water management design to minimise As dispersion.

  1. LINCOLN CREEK ROADLESS AREA, NEVADA.

    USGS Publications Warehouse

    John, David A.; Stebbins, Scott A.

    1984-01-01

    On the basis of a mineral survey, the Lincoln Creek Roadless Area, Nevada was determined to have little likelihood for the occurrence of mineral resources. Geologic terrane favorable for the occurrence of contact-metasomatic tungsten deposits exists, but no evidence for this type of mineralization was identified. The geologic setting precludes the occurrence of fossil fuels and no other energy resources were identified.

  2. Parachute Creek Shale Oil Program

    SciTech Connect

    Not Available

    1981-01-01

    This pamphlet describes Union Oil's shale oil project in the Parachute Creek area of Garfield County, Colorado. The oil shale is estimated to contain 1.6 billion barrels of recoverable oil in the high Mahogany zone alone. Primarily a public relations publication, the report presented contains general information on the history of the project and Union Oil's future plans. (JMT)

  3. Tidal disruption event demographics

    NASA Astrophysics Data System (ADS)

    Kochanek, C. S.

    2016-09-01

    We survey the properties of stars destroyed in tidal disruption events (TDEs) as a function of black hole (BH) mass, stellar mass and evolutionary state, star formation history and redshift. For M_{BH} ≲ 10^7 M_{⊙}, the typical TDE is due to a M* ˜ 0.3 M⊙ M-dwarf, although the mass function is relatively flat for M_{ast } ≲ M_{⊙}. The contribution from older main-sequence stars and sub-giants is small but not negligible. From MBH ≃ 107.5-108.5 M⊙, the balance rapidly shifts to higher mass stars and a larger contribution from evolved stars, and is ultimately dominated by evolved stars at higher BH masses. The star formation history has little effect until the rates are dominated by evolved stars. TDE rates should decline very rapidly towards higher redshifts. The volumetric rate of TDEs is very high because the BH mass function diverges for low masses. However, any emission mechanism which is largely Eddington-limited for low BH masses suppresses this divergence in any observed sample and leads to TDE samples dominated by MBH ≃ 106.0-107.5 M⊙ BHs with roughly Eddington peak accretion rates. The typical fall-back time is relatively long, with 16 per cent having tfb < 10-1 yr (37 d), and 84 per cent having longer time-scales. Many residual rate discrepancies can be explained if surveys are biased against TDEs with these longer tfb, which seems very plausible if tfb has any relation to the transient rise time. For almost any BH mass function, systematic searches for fainter, faster time-scale TDEs in smaller galaxies, and longer time-scale TDEs in more massive galaxies are likely to be rewarded.

  4. Tidal Boundary Conditions in SEAWAT

    USGS Publications Warehouse

    Mulligan, Ann E.; Langevin, Christian; Post, Vincent E.A.

    2011-01-01

    SEAWAT, a U.S. Geological Survey groundwater flow and transport code, is increasingly used to model the effects of tidal motion on coastal aquifers. Different options are available to simulate tidal boundaries but no guidelines exist nor have comparisons been made to identify the most effective approach. We test seven methods to simulate a sloping beach and a tidal flat. The ocean is represented in one of the three ways: directly using a high hydraulic conductivity (high-K) zone and indirect simulation via specified head boundaries using either the General Head Boundary (GHB) or the new Periodic Boundary Condition (PBC) package. All beach models simulate similar water fluxes across the upland boundary and across the sediment-water interface although the ratio of intertidal to subtidal flow is different at low tide. Simulating a seepage face results in larger intertidal fluxes and influences near-shore heads and salinity. Major differences in flow occur in the tidal flat simulations. Because SEAWAT does not simulate unsaturated flow the water table only rises via flow through the saturated zone. This results in delayed propagation of the rising tidal signal inland. Inundation of the tidal flat is delayed as is flow into the aquifer across the flat. This is severe in the high-K and PBC models but mild in the GHB models. Results indicate that any of the tidal boundary options are fine if the ocean-aquifer interface is steep. However, as the slope of that interface decreases, the high-K and PBC approaches perform poorly and the GHB boundary is preferable.

  5. Tidal boundary conditions in SEAWAT.

    PubMed

    Mulligan, Ann E; Langevin, Christian; Post, Vincent E A

    2011-01-01

    SEAWAT, a U.S. Geological Survey groundwater flow and transport code, is increasingly used to model the effects of tidal motion on coastal aquifers. Different options are available to simulate tidal boundaries but no guidelines exist nor have comparisons been made to identify the most effective approach. We test seven methods to simulate a sloping beach and a tidal flat. The ocean is represented in one of the three ways: directly using a high hydraulic conductivity (high-K) zone and indirect simulation via specified head boundaries using either the General Head Boundary (GHB) or the new Periodic Boundary Condition (PBC) package. All beach models simulate similar water fluxes across the upland boundary and across the sediment-water interface although the ratio of intertidal to subtidal flow is different at low tide. Simulating a seepage face results in larger intertidal fluxes and influences near-shore heads and salinity. Major differences in flow occur in the tidal flat simulations. Because SEAWAT does not simulate unsaturated flow the water table only rises via flow through the saturated zone. This results in delayed propagation of the rising tidal signal inland. Inundation of the tidal flat is delayed as is flow into the aquifer across the flat. This is severe in the high-K and PBC models but mild in the GHB models. Results indicate that any of the tidal boundary options are fine if the ocean-aquifer interface is steep. However, as the slope of that interface decreases, the high-K and PBC approaches perform poorly and the GHB boundary is preferable.

  6. Hydrogeology of the Canal Creek area, Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Oliveros, J.P.; Vroblesky, D.A.

    1989-01-01

    Geologic and borehole geophysical logs made at 77 sites show that the hydrogeologic framework of the study area consists of a sequence of unconsolidated sediments typical of the Coastal Plain of Maryland. Three aquifers and two confining units were delineated within the study area. From the surface down, they are: (1) the surficial aquifer; (2) the upper confining unit; (3) the Canal Creek aquifer; (4) the lower confining unit; and (5) the lower confined aquifer. The aquifer materials range from fine sand to coarse sand and gravel. Clay lenses were commonly found interfingered with the sand, isolating parts of the aquifers. All the units are continuous throughout the study area except for the upper confining unit, which crops out within the study area but is absent in updip outcrops. The unit also is absent within a Pleistocene paleochannel, where it has been eroded. The surficial and Canal Creek aquifers are hydraulically connected where the upper confining unit is absent, and a substantial amount of groundwater may flow between the two aquifers. Currently, no pumping stresses are known to affect the aquifers within the study area. Under current conditions, downward vertical hydraulic gradients prevail at topographic highs, and upward gradients typically prevail near surface-water bodies. Regionally, the direction of groundwater flow in the confined aquifers is to the east and southeast. Significant water level fluctuations correspond with seasonal variations in rainfall, and minor daily fluctuations reflect tidal cycles. (USGS)

  7. Geochemical Differences between two adjacent streams in the Tenaya Lake region of Yosemite National Park

    NASA Astrophysics Data System (ADS)

    Antweiler, R.; Andrews, E. D.

    2010-12-01

    Tenaya and Murphy Creeks are two small, intermittent streams with drainage basins adjacent to each other in the Tenaya Lake region of Yosemite National Park. Tenaya Creek has a drainage basin area of 3.49 km2 ranging in elevation from 2491 to 3012 m; Murphy Creek has a drainage basin size of 7.07 km2 ranging in elevation from 2485 to 2990 m. Both basins are underlain by the Half Dome and Cathedral Peak Granodiorites (Bateman et al, 1983), with chemical compositions that are practically indistinguishable (Bateman et al, 1988). Both streams derive all of their water from snowmelt and rainfall, normally going dry by early August each year. Tenaya Creek flows primarily south-southwest, whereas Murphy Creek predominantly flows south. For nearly all of Tenaya Creek’s length it is bordered by the Tioga Pass Road, the only highway in Yosemite National Park which crosses the Sierras; on the other hand, all of Murphy Creek (except its mouth) is wilderness. During the summers of 2009 and 2010, both creeks were sampled along most of their lengths for major and trace elements. In addition, both streams have been sampled near their mouths periodically during the spring and summer (until they go dry) since 2007. Water discharge has been continuously monitored during this time. Because these streams derive all of their water from snowmelt and rainfall, the water chemistry of each must originate from atmospheric deposition, weathering of the bedrock and/or human or animal inputs. These factors, along with the similarity of the geology, topography and basin orientation, suggest that the water chemistries of the creeks should be similar. Instead, while measured sulfate concentrations in Tenaya and Murphy Creeks are similar in their upper reaches, Tenaya Creek sulfate values are almost double in the lower reaches. No other major or trace element showed a similar pattern, although sodium, potassium, calcium and rubidium showed modest increases. Other concentration differences between

  8. Water quality, bed-sediment quality, and simulation of potential contaminant transport in Foster Creek, Berkeley County, South Carolina, 1991-93

    USGS Publications Warehouse

    Campbell, T.R.; Bower, D.E.

    1996-01-01

    Foster Creek, a freshwater tidal creek in Berkeley County, South Carolina, is located in an area of potential contaminant sources from residential, commercial, light industrial, and military activities. The creek is used as a secondary source of drinking water for the surrounding Charleston area. Foster Creek meets most of the freshwater- quality requirements of State and Federal regulatory agencies, but often contains low concentrations of dissolved oxygen and has been characterized as eutrophic. Investigations of water- and bed-sediment quality were made between 1991 and 1993 to assess the effects of anthropogenic sources of contamination on Foster Creek. Low-flow surface-water samples were generally free of toxic compounds with the exception of laboratory artifacts and naturally occurring trace metals. Storm-runoff samples generally contained very low concentrations (near detection limits) of a small number of volatile and semivolatile organics and naturally occurring trace metals. Concentrations of toxic compounds in excess of current (1995) South Carolina Department of Health and Environmental Control and U.S. Environmental Protection Agency regulations were not detected in surface-water samples collected from Foster Creek. Chemical analyses of streambed sediments indicated minimal anthropogenic effects on sediment quality. The particle-tracking option of the U.S. Geological Survey one-dimensional unsteady-flow model (BRANCH) indicated that as the simulated volume of rainfall runoff increased in the Foster Creek Basin, simulated particles in Foster Creek were transported greater distances. Simulating flow through the Bushy Park Dam (also known as Back River Dam) had little effect on particle movement in Foster Creek. Simulating typical withdrawal rates at a water-supply intake resulted in a slight attraction of particles toward the intake during conditions of relatively low runoff. These withdrawals had a greater influence on particles downstream of the intake

  9. Tidal-scale flow routing and sedimentation in mangrove forests: Combining field data and numerical modelling

    NASA Astrophysics Data System (ADS)

    Horstman, E. M.; Dohmen-Janssen, C. M.; Bouma, T. J.; Hulscher, S. J. M. H.

    2015-01-01

    Tidal-scale biophysical interactions establish particular flow routing and sedimentation patterns in coastal mangroves. Sluggish water flows through the mangrove vegetation and enhanced sediment deposition are essential to maintain these valuable ecosystems, thereby enabling their contribution to coastal protection and stabilization. Spatially explicit field observations of tidal-scale flow routing and sediment deposition were obtained in an elevated mangrove stand dissected by tidal creeks, located in the Trang river estuary at the Thai Andaman coast. An accurate and efficient depth-averaged process-based numerical model of this field site was developed in Delft3D to study the contributions of various biogeophysical mangrove settings to the observed tidal dynamics and to study the impacts of changes of these environmental conditions. The creeks are found to form the major pathway for the tidal inflow during the lower tides, while the sheltered interior of the forest is an effective sediment sink during the higher tides. A numerical sensitivity analysis of the initial response-or adaptive capacity-of the studied mangrove system to instantaneous environmental changes reveals the stable state of the study site: deposition rates are largely imposed by the topography and relative elevation, while they are rather independent of the vegetation density. Deeper inundations of the mangroves favor sheet flows through the forest and spatially averaged deposition rates decrease, particularly when this coincides with decreasing vegetation densities. Moreover, the sediment trapping efficiency is found to reduce significantly with diminishing sediment inputs and with mangrove area losses. These results clearly indicate the sensitivity of mangroves' ecosystem engineering ability-in terms of sedimentation-to climate change and anthropogenic threats.

  10. Tidal dynamics of transiting exoplanets

    NASA Astrophysics Data System (ADS)

    Fabrycky, Daniel C.

    2011-11-01

    Transits give us the mass, radius, and orbital properties of the planet, all of which inform dynamical theories. Two properties of the hot Jupiters suggest they had a dramatic origin via tidal damping from high eccentricity. First, the tidally circularized planets (in the 1-4 day pile-up) lie along a relation or boundary in the mass-period plane. This observation may implicate a tidal damping process regulated by planetary radius inflation and Roche lobe overflow, early in the planets' lives. Second, the host stars of many planets have spins misaligned from the planets' orbits. This observation was not expected a priori from the conventional disk migration theory, and it was a boon for the alternative theories of planet-planet scattering and Kozai cycles, accompanied by tidal friction, which predicted it. Now we are faced with a curious observation that the misalignment angle depends on the stellar temperature. It may mean that the tide raised on the stars realigns them, the final result being the tidal consumption of hot Jupiters.

  11. TIDAL LIMITS TO PLANETARY HABITABILITY

    SciTech Connect

    Barnes, Rory; Jackson, Brian; Greenberg, Richard; Raymond, Sean N.

    2009-07-20

    The habitable zones (HZs) of main-sequence stars have traditionally been defined as the range of orbits that intercept the appropriate amount of stellar flux to permit surface water on a planet. Terrestrial exoplanets discovered to orbit M stars in these zones, which are close-in due to decreased stellar luminosity, may also undergo significant tidal heating. Tidal heating may span a wide range for terrestrial exoplanets and may significantly affect conditions near the surface. For example, if heating rates on an exoplanet are near or greater than that on Io (where tides drive volcanism that resurfaces the planet at least every 1 Myr) and produce similar surface conditions, then the development of life seems unlikely. On the other hand, if the tidal heating rate is less than the minimum to initiate plate tectonics, then CO{sub 2} may not be recycled through subduction, leading to a runaway greenhouse that sterilizes the planet. These two cases represent potential boundaries to habitability and are presented along with the range of the traditional HZ for main-sequence, low-mass stars. We propose a revised HZ that incorporates both stellar insolation and tidal heating. We apply these criteria to GJ 581 d and find that it is in the traditional HZ, but its tidal heating alone may be insufficient for plate tectonics.

  12. Seasonal variations in suspended-sediment dynamics in the tidal reach of an estuarine tributary

    USGS Publications Warehouse

    Downing-Kunz, Maureen A.; Schoellhamer, David H.

    2013-01-01

    Quantifying sediment supply from estuarine tributaries is an important component of developing a sediment budget, and common techniques for estimating supply are based on gages located above tidal influence. However, tidal interactions near tributary mouths can affect the magnitude and direction of sediment supply to the open waters of the estuary. We investigated suspended-sediment dynamics in the tidal reach of Corte Madera Creek, an estuarine tributary of San Francisco Bay, using moored acoustic and optical instruments. Flux of both water and suspended-sediment were calculated from observed water velocity and turbidity for two periods in each of wet and dry seasons during 2010. During wet periods, net suspended-sediment flux was seaward; tidally filtered flux was dominated by the advective component. In contrast, during dry periods, net flux was landward; tidally filtered flux was dominated by the dispersive component. The mechanisms generating this landward flux varied; during summer we attributed wind–wave resuspension in the estuary and subsequent transport on flood tides, whereas during autumn we attributed increased spring tide flood velocity magnitude leading to local resuspension. A quadrant analysis similar to that employed in turbulence studies was developed to summarize flux time series by quantifying the relative importance of sediment transport events. These events are categorized by the direction of velocity (flood vs. ebb) and the magnitude of concentration relative to tidally averaged conditions (relatively turbid vs. relatively clear). During wet periods, suspended-sediment flux was greatest in magnitude during relatively turbid ebbs, whereas during dry periods it was greatest in magnitude during relatively turbid floods. A conceptual model was developed to generalize seasonal differences in suspended-sediment dynamics; model application to this study demonstrated the importance of few, relatively large events on net suspended-sediment flux

  13. Field observations and morphodynamic modeling of spontaneous tidal network formation within a constructed salt marsh

    NASA Astrophysics Data System (ADS)

    D'Alpaos, A.; Lanzoni, S.; Marani, M.; Rinaldo, A.

    2007-12-01

    We have monitored and analyzed, through remote sensing and ancillary field surveys, the rapid (O(1) year) development of a tidal network within a newly established artificial salt marsh in the Venice Lagoon. After the construction of the salt marsh, a network of volunteer creeks established themselves away from an artificially constructed main channel (with mean and maximum annual headward-growth rates of 11 m/yr and 18 m/yr, respectively). The rapid formation of this system of tidal creeks provides a unique opportunity to test the reliability of a model of tidal network initiation and development, previously proposed by the authors. The restored marsh presents the characteristics of a controlled environment analogous to a large-scale field laboratory, as it allows comparison of the morphologic features of real and simulated network structures under the reasonable assumption of neglecting accretion and deposition processes over the timescales of observation. Our results compare favorably with observational evidence, showing that the model proves reasonably capable of reproducing the main features of the actual channel-network patterns. The model reproduces statistical network characteristics of eco-morphodynamic and hydrodynamic relevance and captures the dominant modes of the network-incision process.

  14. Spontaneous tidal network formation within a constructed salt marsh: Observations and morphodynamic modelling

    NASA Astrophysics Data System (ADS)

    D'Alpaos, Andrea; Lanzoni, Stefano; Marani, Marco; Bonometto, Andrea; Cecconi, Giovanni; Rinaldo, Andrea

    2007-11-01

    We have monitored and analyzed, through remote sensing and ancillary field surveys, the rapid (O(1) year) development of a tidal network within a newly established artificial salt marsh in the Venice Lagoon. After the construction of the salt marsh, a network of volunteer creeks established themselves away from an artificially constructed main channel (with mean and maximum annual headward-growth rates of 11 m/yr and 18 m/yr, respectively). The rapid formation of this system of tidal creeks provides a unique opportunity to test the reliability of a model of tidal network initiation and development, previously proposed by the authors. The restored marsh presents the characteristics of a controlled environment analogous to a large-scale field laboratory, as it allows comparison of the morphologic features of real and simulated network structures under the reasonable assumption of neglecting accretion and deposition processes over the timescales of observation. Our results compare favorably with observational evidence, showing that the model proves reasonably capable of reproducing the main features of the actual channel-network patterns. The model reproduces statistical network characteristics of eco-morphodynamic and hydrodynamic relevance and captures the dominant modes of the network-incision process.

  15. Meandering: fluvial versus tidal. (Invited)

    NASA Astrophysics Data System (ADS)

    Seminara, G.

    2009-12-01

    Tidal meanders (Marani et al, Water Resour Res, 2002) display similarities as well as important differences from fluvial meanders (Seminara, J Fluid Mech, 2006). Like fluvial meanders they have characteristic wavelengths scaling with channel width: this is why the convergent character of tidal channels leads to meander wavelengths decaying landward. Unlike fluvial meanders, the typical curvature spectra of tidal meanders contain even harmonics: hence, meander skewing does non display any distinct correlation with the flow direction and the known Kinoshita curve, which approximates the shape of fluvial meanders, is not appropriate to tidal meanders. Additional constraints are brought up by the spatial gradients of the basic bed profile connected to the finite length of tidal channels at equilibrium. In fact, it has been theoretically established (Schuttelaars and De Swart, Eur J Mech, B/Fluids, 1996, Seminara et al, J Fluid Mech submitted, 2009) and confirmed by controlled laboratory experiments (Tambroni et al., J Geoph Res, 2005) that tidal channels closed at one end and connected at the other end with a tidal sea, evolve towards an equilibrium configuration characterized by a ‘slow’ landward decay of the average flow depth. An equilibrium length of the channel is then determined by the formation of a shoreline. Channel curvature affects the lateral equilibrium topography and gives rise to a pattern of point bars and scour pools resembling that of fluvial channels. With some notable differences, though. In fact, Solari et al (J Fluid Mech, 2001) showed that long sequences of weakly sinuous identical meandering channels subject to a symmetrical tidal forcing develop a symmetrical bar-pool pattern with small symmetrical oscillations during the tidal cycle. However, in the laboratory investigations of Garotta et al. (Proceedings RCEM5,2007) the bar-pool pattern was somehow unexpected. In a first experiment, it was in phase with curvature only in the inner half of

  16. Korea tidal power and beyond

    NASA Astrophysics Data System (ADS)

    Song, W. O.; van Walsum, E.

    A study evaluating the tidal power potential on the west coast of Korea is presented. The tidal power plant concept applied to all sites features prefabricated caissons from which the powerhouse and the sluice sections of the plant are built up. In the screening process, all 13 potential sites were compared on the basis of a single basin and single effect schemes operated to produce the maximum amount of energy. The four sites identified as having potential for development (the inner Asan Bay, the outer Asan Bay, the Incheon Bay, and the Garorim Bay) are economically evaluated. It is noted that harbor development and land reclamation can proceed in conjunction with tidal power development.

  17. Summary geochemical maps, Hoover Wilderness and adjacent study area, Mono and Tuolumne counties, California

    USGS Publications Warehouse

    Chaffee, M.A.; Hill, R.H.; Sutley, S.J.

    1984-01-01

    The Hoover Wilderness and the adjacent Hoover Extension (East), Hoover Extension (West), and Cherry Creek A Roadless Areas (the adjacent study area) encompass approximately 153,900 acres (241 mi2; 623 km2) in the Inyo, Stanislaus, and Toiyabe Naitonal Forests, Mono and Tuolumne Counties, Calif. These two areas lie along and mostly east of the crest of the Sierra Nevada, along the north and east sides of Yosemite National Park. Elevations vary from a high of 12,446 ft (3,793 m) on the crest of the Sierra Nevada to a low of about 6,500 ft (1,981 m) near the Bridgeport Ranger Station. Access to the Hoover Wilderness and adjacent study area is by U.S. Highway 395, California State Highways 108 (Sonora Pass) and 120 (Tioga Pass), and by other paved and graded roads that lead off of these U.S. and State highways.

  18. Tidal disruption of dissipative planetesimals

    NASA Astrophysics Data System (ADS)

    Mizuno, H.; Boss, A. P.

    1985-07-01

    A self-consistent numerical model is developed for the tidal disruption of a solid planetesimal. The planetesimal is treated as a highly viscous, slightly compressible fluid whose disturbed parts are an inviscid, pressureless fluid undergoing distortion and disruption. The distortions were constrained to being symmetrical above and below the equatorial plane. The tidal potential is expanded in terms of Legendre polynomials, which eliminates the center of mass acceleration effects, permitting definition of equations of motion in a noninertial frame. Consideration is given to viscous dissipation and to characteristics of the solid-atmosphere boundary. The model is applied to sample cases in one, two and three dimensions.

  19. RICHLAND CREEK ROADLESS AREA, ARKANSAS.

    USGS Publications Warehouse

    Miller, Mary H.; Wood, Robert H.

    1984-01-01

    On the basis of geologic and mineral surveys, Richland Creek Roadless Area, Arkanses, has little promise for the occurrence of metallic mineral resources, gas and oil, or oil shale. The Boone Formation of Mississippian age and the Everton Formation of Ordovician age, both known to contain zinc and lead deposits in northern Arkansas, underlie the roadless area. The presence or absence of zinc and lead deposits in these formations in the subsurface can be neither confirmed nor ruled out without exploratory drilling. Most of the Richland Creek Roadless Area is under lease for oil and gas; however two wells drilled near the eastern boundary of the area did not show contained gas or oil.

  20. Preservation of daily tidal cycles and stacked alluvial swamp deposits: Depositional response to early compaction of buried peat bodies

    SciTech Connect

    Demko, T.M.; Gastaldo, R.A. )

    1990-05-01

    The character of the clastic depositional environments represented in the lower Mary Lee coal zone of the Pennsylvanian Pottsville Formation in the Warrior basin Alabama (tidally influenced mud flats and alluvial swamps) was controlled by the compaction of buried peat bodies. The lowest mineable coal in the Mary Lee coal zone, the Jagger, is overlain by laminated shale and sandstone exhibiting pronounced cycle bedding. This bedding records daily tidal cyclicity in the form of sand-mud couplets. These correspond to flood-current deposition of the coarser fraction followed by fallout of the finer grained fraction during ensuing slack-water periods. These couplets are cyclically bundled-sandier bundles corresponding to spring tides and muddier bundles to neap tides (lamination counts suggest a 24-30-day cycle). The clastic sequence above the overlying Blue Creek coal is characterized by a series of stacked alluvial swamp horizons. These can be identified by autochthonous fossil plants and pedological features indicative of gleyed paleosols. Catastrophic flooding buried and preserved these horizons. The rapid, early compaction of the buried Jagger and Blue Creek peat bodies created accommodation space that allowed both the preservation of tidalites in the Jagger coal to Blue Creek coal interval and the stacking of alluvial swamp paleosols above the Blue Creek seam. Carboniferous peats were comprised of highly compressible plant parts and hence, were sensitive to sediment loading. Once the peat bodies had compressed to a certain extent, stability of the overlying sediment surface created conditions amenable to resumption of peat accumulation.

  1. Evaluation of protected, threatened, and endangered fish species in Upper Bear Creek watershed

    SciTech Connect

    Ryon, M.G.

    1998-07-01

    The East Bear Creek Site for the proposed centralized waste facility on the US Department of Energy`s Oak Ridge Reservation was evaluated for potential rare, threatened or endangered (T and E) fish species in the six primary tributaries and the main stem of Bear Creek that are within or adjacent to the facility footprint. These tributaries and portion of Bear Creek comprise the upper Bear Creek watershed. One T and E fish species, the Tennessee dace (Phoxinus tennesseensis), was located in these streams. The Tennessee dace is listed by the State of Tennessee as being in need of management, and as such its habitat is afforded some protection. Surveys indicated that Tennessee dace occupy the northern tributaries NT-1, NT-4, and NT-5, as well as Bear Creek. Several specimens of the dace were gravid females, indicating that the streams may function as reproductive habitat for the species. The implications of impacts on the species are discussed and mitigation objectives are included.

  2. A tale of two interfaces: Dynamic nitrate removal in the hyporheic zone of a tidal fresh river

    NASA Astrophysics Data System (ADS)

    Sawyer, A. H.; Knights, D. H.; Barnes, R. T.; Wallace, C.; Bray, S. N.; Musial, C.

    2015-12-01

    At the interface of rivers and oceans, tidal freshwater zones (TFZs) stretch for tens to hundreds of kilometers but are rarely monitored for nitrogen export due to their complex hydrodynamics. Field observations from the TFZ of White Clay Creek (Delaware, USA) show that river discharge and nitrate export rates decrease during rising tide, while hyporheic storage increases. During falling tide, river discharge and nitrate export rates increase, while stored hyporheic water is released to the river. We estimate that 11% of river water exchanges through the hyporheic zone of this TFZ due to tidal pumping alone. We developed a one-dimensional, coupled fluid flow and solute transport model to quantify the influence of tidal pumping on nitrate removal in the riverbed. Tidal pumping promotes a deep, oscillating zone of aerobic respiration that limits denitrification near the sediment-water interface. As tide rises, groundwater residence times in shallow riverbed sediments increase, which causes a doubling of denitrification rates relative to falling tide. Given a uniform substrate along TFZs, removal rates of groundwater-borne nitrate should decrease as tidal amplitude increases downstream. Denitrification hot spots should occur in less permeable, organic-rich sediment under low tidal ranges. Because TFZs connect lowland nitrogen sources to the ocean, it is imperative that we expand monitoring efforts and elucidate their role in nitrogen export to the coast.

  3. What Makes a Tidal Tail?

    NASA Astrophysics Data System (ADS)

    Rodruck, Michael; Konstantopoulos, I.; Charlton, J. C.

    2014-01-01

    Galaxy interactions are famous for creating some of the most visually stunning scenes in astronomy, particularly in the cases of tidal tails. These chaotic regions are known to house breeding grounds for young stellar clusters, as shown through past imaging and spectroscopic studies, but the underlying material remains a mystery. While we know that gas is easily stripped from the parent galaxies, what about the stars? The presence of an older stellar population is crucial to dynamical simulations of tidal tails, but has not yet been confirmed by observation. We use the twin tidal tails of NGC3256 as a case study for determining the presence of an old, underlying stellar population. Newly acquired ugriz Gemini data allows us to distinguish between young and old stars, while previous HST data pinpoints the locations of these objects. Deep imaging surveys have often been used to detect tidal features, including these ancient relics, but our survey will be the first to measure the colors of such objects. This will lead us to place constraints on the original composition of the material that was ejected from the interacting/merging galaxies, and the star formation history.

  4. Methane cycling in a tidal freshwater swamp

    SciTech Connect

    Megonigal, J.P.; Schlesinger, W.H. )

    1993-06-01

    Previous studies of methanogenesis in a tidal freshwater swamp on the North Carolina coast have found that potential rates of methane production overestimate observed rates of methane flux, especially during summer months. This research investigates three possibilities for the unexplained losses: methane oxidation, lateral export of dissolved methane to the adjacent river, and ebullition. It is possible that each of these sinks increase during the summer. The potential for methane oxidation was demonstrated in intact soil cores incubated for 21 hours under a 0.5% CH[sub 3]F atmosphere. Methane flux increased from 10+/-27 (mean+/-sd) to 60+/-3 mg m[sup [minus]2] d[sup [minus]1] in treated cores; control core fluxes were 15+/-3 and 19+/-3 mg m[sup [minus]2] d[sup [minus]1] over the same periods. Incubations of slightly unsaturated soils with [sup 14]CH[sub 4] confirmed rapid potential rates of methane oxidation.

  5. Floods in Starkweather Creek basin, Madison, Wisconsin

    USGS Publications Warehouse

    Lawrence, Carl L.; Holmstrom, Barry K.

    1972-01-01

    The reaches evaluated are (1) Starkweather Creek and West Branch Starkweather Creek, for a distance of 6.0 river miles from the mouth at Lake Monona upstream to the U.S. Highway 51 crossing north of Truax Field; and (2) East Branch Starkweather Creek (2.8 river miles), from its confluence with the West Branch near Milwaukee Street upstream to a point near the Interstate Highway 90-94 crossing.

  6. Traveltime characteristics of Gore Creek and Black Gore Creek, upper Colorado River basin, Colorado

    USGS Publications Warehouse

    Gurdak, Jason J.; Spahr, Norman E.; Szmajter, Richard J.

    2002-01-01

    In the Rocky Mountains of Colorado, major highways are often constructed in stream valleys. In the event of a vehicular accident involving hazardous materials, the close proximity of highways to the streams increases the risk of contamination entering the streams. Recent population growth has contributed to increased traffic volume along Colorado highways and has resulted in increased movement of hazardous materials, particularly along Interstate 70. Gore Creek and its major tributary, Black Gore Creek, are vulnerable to such contamination from vehicular accidents along Interstate 70. Gore Creek, major tributary of the Eagle River, drains approximately 102 square miles, some of which has recently undergone significant urban development. The headwaters of Gore Creek originate in the Gore Range in the eastern part of the Gore Creek watershed. Gore Creek flows west to the Eagle River. Beginning at the watershed boundary on Vail Pass, southeast of Vail Ski Resort, Interstate 70 parallels Black Gore Creek and then closely follows Gore Creek the entire length of the watershed. Interstate 70 crosses Gore Creek and tributaries 20 times in the watershed. In the event of a vehicular accident involving a contaminant spill into Gore Creek or Black Gore Creek, a stepwise procedure has been developed for water-resource managers to estimate traveltimes of the leading edge and peak concentration of a conservative contaminant. An example calculating estimated traveltimes for a hypothetical contaminant release in Black Gore Creek is provided. Traveltime measurements were made during May and September along Black Gore Creek and Gore Creek from just downstream from the Black Lakes to the confluence with the Eagle River to account for seasonal variability in stream discharge. Fluorometric dye injection of rhodamine WT and downstream dye detection by fluorometry were used to measure traveltime characteristics of Gore Creek and Black Gore Creek. During the May traveltime measurements

  7. Preliminary estimates of the quantity and quality of groundwater discharge to a section of Bear Creek in central Iowa

    SciTech Connect

    Caron, G.A.; Simpkins, W.W.; Schultz, R.C. )

    1994-04-01

    Studies in Iowa and elsewhere in the Midwest have suggested that most agrichemicals enter surface water through runoff events of tile drainage. Although it also contains agrichemicals, groundwater's contribution to surface water contamination is largely unknown, particularly in till-dominated watersheds. The purpose of this study was to estimate the quantity and quality of groundwater discharge to a 1,000-m-long section of Bear Creek in central Iowa. The study is part of a larger project that is evaluating constructed, multi-species riparian buffer strips as a Best Management Practice for agriculture. Groundwater discharge to the creek was estimated using: (1) differences in discharge between an upstream and downstream weir (minus tile drain outflow), (2) seepage meter data from the creek bed, and (3) Darcy's Law, using hydraulic gradient and K data from piezometers adjacent to the creek and minipiezometers in the creek. The authors preliminary estimates show groundwater discharge rates of 2 to 15 L/s (weirs), 10 L/s (seepage meters), and 3 L/s (Darcy's Law). Discharge in Bear Creek ranged from 100 to 400 L/s during the period; thus, groundwater contributed only a small part of the total creek discharge. Water samples from minipiezometers beneath the creek bed are characterized by NO[sub 3]-N concentrations < 3 mg/L and atrazine concentrations < 0.1 [mu]g/L. In contrast, water samples from Bear Creek typically show NO[sub 3]-N concentrations > 20 mg/L and atrazine concentrations up to 1.0 [mu]g/L. These water quality data suggest that groundwater may not be a significant contributor to agrichemical contamination of surface water in this till-dominated watershed.

  8. 33 CFR 110.79c - Fish Creek Harbor, Fish Creek, Wisconsin.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Fish Creek Harbor, Fish Creek, Wisconsin. 110.79c Section 110.79c Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.79c Fish Creek Harbor, Fish...

  9. 33 CFR 110.79c - Fish Creek Harbor, Fish Creek, Wisconsin.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Fish Creek Harbor, Fish Creek, Wisconsin. 110.79c Section 110.79c Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.79c Fish Creek Harbor, Fish...

  10. 33 CFR 110.79c - Fish Creek Harbor, Fish Creek, Wisconsin.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Fish Creek Harbor, Fish Creek, Wisconsin. 110.79c Section 110.79c Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.79c Fish Creek Harbor, Fish...

  11. 33 CFR 110.79c - Fish Creek Harbor, Fish Creek, Wisconsin.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Fish Creek Harbor, Fish Creek, Wisconsin. 110.79c Section 110.79c Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.79c Fish Creek Harbor, Fish...

  12. 33 CFR 110.79c - Fish Creek Harbor, Fish Creek, Wisconsin.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Fish Creek Harbor, Fish Creek, Wisconsin. 110.79c Section 110.79c Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Special Anchorage Areas § 110.79c Fish Creek Harbor, Fish...

  13. 78 FR 62616 - Salmon Creek Hydroelectric Company, Salmon Creek Hydroelectric Company, LLC; Notice of Transfer...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-22

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Salmon Creek Hydroelectric Company, Salmon Creek Hydroelectric Company, LLC; Notice of Transfer of Exemption 1. By letter filed September 23, 2013, Salmon Creek Hydroelectric...

  14. Chemical data for bottom sediment, lake water, bottom-sediment pore water, and fish in Mountain Creek Lake, Dallas, Texas, 1994-96

    USGS Publications Warehouse

    Jones, S.A.; Van Metre, P.C.; Moring, J.B.; Braun, C.L.; Wilson, J.T.; Mahler, B.J.

    1997-01-01

    Mountain Creek Lake is a reservoir adjacent to two U.S. Department of the Navy facilities, the Naval Weapons Industrial Reserve Plant and the Naval Air Station in Dallas, Texas. A Resource Conservation and Recovery Act Facility Investigation found ground-water plumes containing chlorinated solvents on both facilities. These findings led to a U.S. Geological Survey study of Mountain Creek Lake adjacent to both facilities between June 1994 and August 1996. Bottom sediments, lake water, bottom-sediment pore water, and fish were collected for chemical analysis.

  15. Tidal fluxes of dissolved oxygen at the North Inlet-Winyah Bay National Estuarine Research Reserve

    NASA Astrophysics Data System (ADS)

    Gardner, L. R.; Kjerfve, B.; Petrecca, D. M.

    2006-04-01

    Advective, dispersive and total dissolved oxygen (DO) fluxes from 1297 complete tidal cycles were analyzed to test the "outwelling" hypothesis as it pertains to DO. A 910 day time series of meteorological and water quality data (approximately 35,000 half-hourly observations) was used to assess DO fluxes and dynamics at Crab Haul Creek, a small (1.1 km 2) tidal salt marsh basin at North Inlet, South Carolina, within the North Inlet-Winyah Bay National Estuarine Research Reserve. A basin storage curve, derived from water velocity measurements made across a permanent transect in the tidal creek every half hour for eight semidiurnal tidal cycles, enabled water discharges to be estimated from tide height readings in the 910 day time series. The discharges along with DO concentration measurements were used to calculate DO fluxes for each tidal cycle in the series. The long-term mean dispersive and advective DO fluxes were -0.281 g O 2 s -1 and -0.375 g O 2 s -1, respectively. Based on " t" tests both means are significantly less than zero ( p < 0.02), indicating exports. Furthermore a significant correlation was found between the dispersive DO export and the tidal mean solar radiation, indicating that photosynthesis is the principal process driving the dispersive export of DO. On the other hand no significant correlations were found between the advective export of DO and solar radiation or between the dispersive fluxes of DO and salt. The absence of such correlations indicates that the advective export of DO is simply an artifact of a slight ebb sampling bias in our computation of the tidal mean discharge. On a unit area basis the average annual dispersive export of DO is 8.9 g m -2 yr -1 or 0.28 mol DO m -2 yr -1. This is a small fraction of the oxygen produced in the basin by phytoplankton (18 mol DO m -2 yr -1) and its contribution to the DO resources of the receiving waters is far exceeded by the oxygen demand associated with the concurrent export of dissolved

  16. Rejuvenating Poldered Landscapes in a Tidally-Dominated, Sediment-Rich Delta: A Numerical Model and Analysis of the Effectiveness of Tidal River Management in Coastal Bangladesh

    NASA Astrophysics Data System (ADS)

    Tasich, C. M.; Goodbred, S. L., Jr.; Gilligan, J. M.; Wilson, C.

    2014-12-01

    The low-lying, coastal region of Bangladesh has relied on poldering (the creation of embanked islands) since the 1960s to mitigate the effects of tidal inundation and storm surge from tropical cyclones. The result has been an increase in total arable land and the ability to sustain food production for one of the most densely populated countries in the world. However, poldering has had the unintended consequences of starving embanked landscapes of sediment and increasing high water levels through tidal amplification. Thus, polder elevations have been declining while tidal channels have been aggrading. Recent small-scale engineering projects, locally referred to as tidal river management (TRM), have attempted to combat these effects by allowing water and sediment exchange between the polders and the tidal network. Anecdotal reports claim great success for TRM in some locations, but not in others. However, to date there has been almost no quantitative analysis. Here, we used measured sedimentation rates and water level data from Polder 32 (P32) and the adjacent pristine mangrove forest in southwest Bangladesh to parameterize a simple model of tidal inundation and resultant sediment accretion. P32 elevations are currently ~1 m lower than natural elevations resulting in ~105 cm of tidal inundation when embankments were breached versus only ~20 cm for the mangrove forest. We measured sedimentation rates of 20 cm/yr and 1 cm/yr, respectively. When normalized to the cumulative annual flooding depth, the resulting sediment extraction rates yield similar values of 300 mg/L and 230 mg/L. We employ these flooding depth and sediment extraction parameters in our model to quantify the amount of time and sediment needed to re-equilibrate the lowered polder elevation to that of the natural environment. Although relatively simple, results from this preliminary model corroborate anecdotes of TRM's effectiveness at restoring land-surface elevations in the polders of Bangladesh. Future

  17. 1. OVERALL VIEW OF LOBOS CREEK INLET STRUCTURE (#1786), LOOKING ...

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

    1. OVERALL VIEW OF LOBOS CREEK INLET STRUCTURE (#1786), LOOKING SOUTHWEST - Presidio Water Treatment Plant, Lobos Creek Inlet Structure, East of Lobos Creek at Baker Beach, San Francisco, San Francisco County, CA

  18. General perspective view of the Spring Creek Bridge, view looking ...

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

    General perspective view of the Spring Creek Bridge, view looking east. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  19. Approach view of the Spring Creek Bridge, view looking north. ...

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

    Approach view of the Spring Creek Bridge, view looking north. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  20. General perspective view of the Spring Creek Bridge, view looking ...

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

    General perspective view of the Spring Creek Bridge, view looking southeast. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  1. Approach view of the Spring Creek Bridge, view looking south. ...

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

    Approach view of the Spring Creek Bridge, view looking south. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  2. Topographic view of the Spring Creek Bridge and Collier State ...

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

    Topographic view of the Spring Creek Bridge and Collier State Park, view looking east. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  3. Elevation view of the Spring Creek Bridge, view looking east. ...

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

    Elevation view of the Spring Creek Bridge, view looking east. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  4. General perspective view of the Spring Creek Bridge, view looking ...

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

    General perspective view of the Spring Creek Bridge, view looking northwest. - Spring Creek Bridge, Spanning Spring Creek at Milepoint 253.98 on Oregon to California Highway (US Route 97), Chiloquin, Klamath County, OR

  5. 128. Credit JE. Outlet of tunnel on South Battle Creek ...

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

    128. Credit JE. Outlet of tunnel on South Battle Creek Canal immediately above Junction with Cross Country Canal. (JE, v. 25 1910 p. 118). - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  6. 2. GENERAL VIEW SHOWING SIMPSON CREEK BRIDGE WITH BRIDGEPORT LAMP ...

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

    2. GENERAL VIEW SHOWING SIMPSON CREEK BRIDGE WITH BRIDGEPORT LAMP AND CHIMNEY COMPANY IN BACKGROUND. - Bridgeport Lamp Chimney Company, Simpson Creek Bridge, Spanning Simpson Creek, State Route 58 vicinity, Bridgeport, Harrison County, WV

  7. 7. Cable Creek Bridge after completion. Zion National Park negative ...

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

    7. Cable Creek Bridge after completion. Zion National Park negative number 1485, classification series 002, 12. - Floor of the Valley Road, Cable Creek Bridge, Spanning Cable Creek on Floor of Valley, Springdale, Washington County, UT

  8. 3. EAGLE CREEK RECREATION AREA, VIEW OF PICNIC AREA WITH ...

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

    3. EAGLE CREEK RECREATION AREA, VIEW OF PICNIC AREA WITH COMMUNITY KITCHEN IN BACKGROUND. - Historic Columbia River Highway, Eagle Creek Recreation Area, Historic Columbia River Highway at Eagle Creek, Troutdale, Multnomah County, OR

  9. Detail view of the Ten Mile Creek Bridge, view looking ...

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

    Detail view of the Ten Mile Creek Bridge, view looking northeast at the modified "X" bracing and concrete hangers. - Ten Mile Creek Bridge, Spanning Ten Mile Creek on Oregon Coast Highway, Yachats, Lincoln County, OR

  10. Detail view of the Ten Mile Creek Bridge decorative concrete ...

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

    Detail view of the Ten Mile Creek Bridge decorative concrete arched balustrade at southeast corner of bridge, view looking east. - Ten Mile Creek Bridge, Spanning Ten Mile Creek on Oregon Coast Highway, Yachats, Lincoln County, OR

  11. Detail perspective view of the Ten Mile Creek Bridge arch, ...

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

    Detail perspective view of the Ten Mile Creek Bridge arch, decorative cantilevered balustrade, and floor beams. - Ten Mile Creek Bridge, Spanning Ten Mile Creek on Oregon Coast Highway, Yachats, Lincoln County, OR

  12. 1. Salmon Creek Diversion Dam, weir (to left), sand and ...

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

    1. Salmon Creek Diversion Dam, weir (to left), sand and silt sluice gate (center), main canal headworks (to right), view to northwest - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  13. 2. Salmon Creek Diversion Dam, overview, diversion weir center foreground, ...

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

    2. Salmon Creek Diversion Dam, overview, diversion weir center foreground, headworks overflow weir to center left, view to east - Salmon Creek Diversion Dam, Salmon Creek, Okanogan, Okanogan County, WA

  14. 8. DETAIL VIEW OF DATEPLATE WHICH READS 'HARP CREEK, LUTEN ...

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

    8. DETAIL VIEW OF DATEPLATE WHICH READS 'HARP CREEK, LUTEN BRIDGE CO., CONTRACTOR, ARKANSAS STATE HIGHWAY DEPARTMENT, 1928' - Harp Creek Bridge, Spans Harp Creek at State Highway 7, Harrison, Boone County, AR

  15. 59. Credit FM. Flood waters on South Battle Creek next ...

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

    59. Credit FM. Flood waters on South Battle Creek next to powerhouse. Note height of water in relation to tailraces. - Battle Creek Hydroelectric System, Battle Creek & Tributaries, Red Bluff, Tehama County, CA

  16. Perspective view showing 850 plate girder span directly over creek, ...

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

    Perspective view showing 85-0 plate girder span directly over creek, looking west. - New York, Chicago & St. Louis Railroad, Elk Creek Trestle, Spanning Elk Creek, south of Elk Park Road, Lake City, Erie County, PA

  17. Detail view of 850 plate girder span directly over creek, ...

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

    Detail view of 85-0 plate girder span directly over creek, looking west. - New York, Chicago & St. Louis Railroad, Elk Creek Trestle, Spanning Elk Creek, south of Elk Park Road, Lake City, Erie County, PA

  18. 2. Deep Creek Road, old bridge at campground entrance. ...

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

    2. Deep Creek Road, old bridge at campground entrance. - Great Smoky Mountains National Park Roads & Bridges, Deep Creek Road, Between Park Boundary near Bryson City & Deep Creek Campground, Gatlinburg, Sevier County, TN

  19. 1. Deep Creek Road, picnic pavilion Great Smoky Mountains ...

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

    1. Deep Creek Road, picnic pavilion - Great Smoky Mountains National Park Roads & Bridges, Deep Creek Road, Between Park Boundary near Bryson City & Deep Creek Campground, Gatlinburg, Sevier County, TN

  20. Approach view of the North Fork Butter Creek Bridge, view ...

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

    Approach view of the North Fork Butter Creek Bridge, view looking south - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

  1. Elevation view of the North Fork Butter Creek Bridge, view ...

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

    Elevation view of the North Fork Butter Creek Bridge, view looking west - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

  2. Detail perspective view of the North Fork Butter Creek Bridge, ...

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

    Detail perspective view of the North Fork Butter Creek Bridge, view looking southwest - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

  3. General perspective view of the North Fork Butter Creek Bridge, ...

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

    General perspective view of the North Fork Butter Creek Bridge, view looking north - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

  4. General perspective view of the North Fork Butter Creek Bridge, ...

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

    General perspective view of the North Fork Butter Creek Bridge, view looking south - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

  5. General perspective view of the North Fork Butter Creek Bridge, ...

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

    General perspective view of the North Fork Butter Creek Bridge, view looking southwest - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

  6. Approach view of the North Fork Butter Creek Bridge, view ...

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

    Approach view of the North Fork Butter Creek Bridge, view looking north - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

  7. 2. Big Creek Road, worm fence and road at trailhead. ...

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

    2. Big Creek Road, worm fence and road at trailhead. - Great Smoky Mountains National Park Roads & Bridges, Big Creek Road, Between State Route 284 & Big Creek Campground, Gatlinburg, Sevier County, TN

  8. Active layer hydrology for Imnavait Creek, Toolik, Alaska

    SciTech Connect

    Hinzman, L.D.; Kane, D.L.

    1987-04-01

    The hydrology of the active layer of a watershed is described. In the annual hydrologic cycle, snowmelt is the most significant event at Imnavait Creek located near Toolik Lake, Alaska. Precipitation that has accumulated for more than 6 months on the surface melts in a relatively short period of 7 to 10 days once sustained melting occurs. Significant runoff events are few. Convective storms covering relatively small areas on the North Slope of Alaska can produce significant small-scale events in a small watershed scale,but these events are rapidly attenuated outside the basin. Data collection began in August 1984. We have continuously monitored the hydrologic, the meteorologic, and the soil`s physical conditions. Information was collected through implementation of four snowmelt runoff plots and measurements of essential microclimate parameters. Soil moisture and temperature profiles were measured adjacent to each snowmelt runoff plot, and heat flux is collected adjacent to one of these plots. Meteorological parameters were measured locally. The water content of the snowpack prior to snowmelt was measured throughout the watershed and measured daily adjacent to each plot during snowmelt. The stream draining the basin was measured regularly during the spring melt event to provide information on watershed runoff rates and the volume of snowmelt.

  9. Active layer hydrology for Imnavait Creek, Toolik, Alaska

    SciTech Connect

    Hinzman, L.D.; Kane, D.L.

    1987-04-01

    The hydrology of the active layer of a watershed is described. In the annual hydrologic cycle, snowmelt is the most significant event at Imnavait Creek located near Toolik Lake, Alaska. Precipitation that has accumulated for more than 6 months on the surface melts in a relatively short period of 7 to 10 days once sustained melting occurs. Significant runoff events are few. Convective storms covering relatively small areas on the North Slope of Alaska can produce significant small-scale events in a small watershed scale,but these events are rapidly attenuated outside the basin. Data collection began in August 1984. We have continuously monitored the hydrologic, the meteorologic, and the soil's physical conditions. Information was collected through implementation of four snowmelt runoff plots and measurements of essential microclimate parameters. Soil moisture and temperature profiles were measured adjacent to each snowmelt runoff plot, and heat flux is collected adjacent to one of these plots. Meteorological parameters were measured locally. The water content of the snowpack prior to snowmelt was measured throughout the watershed and measured daily adjacent to each plot during snowmelt. The stream draining the basin was measured regularly during the spring melt event to provide information on watershed runoff rates and the volume of snowmelt.

  10. Relative value of managed wetlands and tidal marshlands for wintering northern pintails

    USGS Publications Warehouse

    Coates, Peter S.; Casazza, Michael L.; Halstead, Brian J.; Fleskes, Joseph P.

    2012-01-01

    Northern pintail Anas acuta (hereafter, pintail) populations have declined substantially throughout the western US since the 1970s, largely as a result of converting wetlands to cropland. Managed wetlands have been developed throughout the San Francisco Bay estuaries to provide wildlife habitat, particularly for waterfowl. Many of these areas were historically tidal baylands and plans are underway to remove dikes and restore tidal action. The relationship between tidal baylands and waterfowl populations is poorly understood. Our objective was to provide information on selection and avoidance of managed and tidal marshland by pintails. During 1991–1993 and 1998–2000, we radio-marked and relocated 330 female pintails (relocations, n =11,574) at Suisun Marsh, the largest brackish water estuary within San Francisco Bay, to estimate resource selection functions during the nonbreeding months (winter). Using a distance-based modeling approach, we calculated selection functions for different ecological communities (e.g., tidal baylands) and investigated variation explained by time of day (day or night hours) to account for differences in pintail behavior (i.e., foraging vs. roosting). We found strong evidence for selection of managed wetlands. Pintails also avoided tidal marshes and bays and channels. We did not detect differences in selection function between day and night hours for managed wetlands but the degree of avoidance of other habitats varied by time of day. We also found that areas subjected to tidal action did not influence the selection of immediately adjacent managed wetlands. If current management goals include providing habitat for wintering waterfowl populations, particularly pintail, then we recommend wildlife managers focus tidal restoration on areas that are not currently managed wetland and/or improve conditions in areas of managed wetlands to increase local carrying capacities

  11. Maine Tidal Power Initiative: Environmental Impact Protocols For Tidal Power

    SciTech Connect

    Peterson, Michael Leroy; Zydlewski, Gayle Barbin; Xue, Huijie; Johnson, Teresa R.

    2014-02-02

    The Maine Tidal Power Initiative (MTPI), an interdisciplinary group of engineers, biologists, oceanographers, and social scientists, has been conducting research to evaluate tidal energy resources and better understand the potential effects and impacts of marine hydro-kinetic (MHK) development on the environment and local community. Project efforts include: 1) resource assessment, 2) development of initial device design parameters using scale model tests, 3) baseline environmental studies and monitoring, and 4) human and community responses. This work included in-situ measurement of the environmental and social response to the pre-commercial Turbine Generator Unit (TGU®) developed by Ocean Renewable Power Company (ORPC) as well as considering the path forward for smaller community scale projects.

  12. Extraction of tidal channel networks from airborne scanning laser altimetry

    NASA Astrophysics Data System (ADS)

    Mason, David C.; Scott, Tania R.; Wang, Hai-Jing

    Tidal channel networks are important features of the inter-tidal zone, and play a key role in tidal propagation and in the evolution of salt marshes and tidal flats. The study of their morphology is currently an active area of research, and a number of theories related to networks have been developed which require validation using dense and extensive observations of network forms and cross-sections. The conventional method of measuring networks is cumbersome and subjective, involving manual digitisation of aerial photographs in conjunction with field measurement of channel depths and widths for selected parts of the network. This paper describes a semi-automatic technique developed to extract networks from high-resolution LiDAR data of the inter-tidal zone. A multi-level knowledge-based approach has been implemented, whereby low-level algorithms first extract channel fragments based mainly on image properties then a high-level processing stage improves the network using domain knowledge. The approach adopted at low level uses multi-scale edge detection to detect channel edges, then associates adjacent anti-parallel edges together to form channels. The higher level processing includes a channel repair mechanism. The algorithm may be extended to extract networks from aerial photographs as well as LiDAR data. Its performance is illustrated using LiDAR data of two study sites, the River Ems, Germany and the Venice Lagoon. For the River Ems data, the error of omission for the automatic channel extractor is 26%, partly because numerous small channels are lost because they fall below the edge threshold, though these are less than 10 cm deep and unlikely to be hydraulically significant. The error of commission is lower, at 11%. For the Venice Lagoon data, the error of omission is 14%, but the error of commission is 42%, due partly to the difficulty of interpreting channels in these natural scenes. As a benchmark, previous work has shown that this type of algorithm

  13. Tidal river hydraulics, morphology, and biogeochemistry: Implications for management and restoration of coastal ecosystems (Invited)

    NASA Astrophysics Data System (ADS)

    Doyle, M. W.; Ensign, S.

    2010-12-01

    While much research exists for rivers and creeks that are entirely within the tidal zone, little geomorphic research exists for the region where rivers encounter tides. TFZs have distinct ecosystem processes shaped by upstream watershed fluxes and tidal forcing from downstream. Population growth worldwide is increasing rapidly in coastal areas; understanding these systems is thus imperative. We sought to quantify how tides affect river hydraulics and sediment transport, how these processes influence morphology over time, and how this altered and evolving morphology influences denitrification and primary productivity. We measured the tidal influence on energy expenditure and sediment transport over semi-diurnal tidal cycles along a 9 km tidal gradient of the Newport River, NC. Tides dampened energy in the upper tidal river relative to non-tidal river, but energy dissipation farther downstream was 44-fold greater than would have occurred without influence of tides. Sediment flux was dominated by tidal cycles rather than storm flows despite the large upstream watershed area. Bankfull channel size increased dramatically along the tidal gradient, much more so than was predicted with normal downstream hydraulic geometry relations. These geomorphic characteristics heavily influenced fundamental ecological processes. Geomorphic-biogeochemical relations were examined by measuring rates of N2 production from sediment cores taken from inter-tidal portion of the river, and in-situ measurements of redox potential in the TFZ riparian zone. Fluctuations between oxidized and reduced conditions, soil moisture, and an inundation from floods or tides were used to model location, timing, and rates of denitrification. By modeling total denitrification flux (kg N per day), we could estimate the influence of hydrology, geomorphology, and tidal forcing on N cycles. Results indicate that tidally-driven changes in channel morphology (e.g., rapid downstream widening), combined with

  14. Simulating hydrodynamics on tidal mudflats

    NASA Astrophysics Data System (ADS)

    Cook, S.; Lippmann, T. C.

    2014-12-01

    Biogeochemical cycling in estuaries is governed by fluxes from both riverine sources and through estuarine sediment deposits. Although estimates from river sources are relatively common and easily sampled, estimates of nutrient fluxes through the fluid-sediment interface are less common and limited to deeper portions of the bays away from intertidal areas. Lack of quantifiable shear stress estimates over intertidal areas limits our overall understanding of nutrient budgets in estuaries. Unfortunately, observation of intertidal hydrodynamics and nutrient fluxes over tidal flats and near the water's edge is difficult owing to the temporally varying and spatially extensive region where the tides inundate, and thus numerical modeling is often employed. In this work, the Regional Ocean Modeling System (ROMS), a three dimensional numerical hydrodynamic model was used to investigate the shear stresses over intertidal mudflats in the Great Bay, a tidally-dominated New England estuary cut by several tidal channels and with over 50% of the estuary exposed at low tide. The ROMS wetting and drying scheme was used to simulate the rising and falling tide on the flats, a successful approach adapted in other regions of the world but not always inclusive of tidal channels. Bathymetric data obtained in 2009 and 2013 was used to define the model grid. Predicted tides are forced at Adam's Pt., a natural constriction in the estuary about 20 km upstream of the mouth and at the entrance to the Great Bay. Of particular interest are fluxes of material on-to and off-of the tidal flats which contribute to water quality conditions in the estuary, and are largely governed by shear stresses that drive nutrient fluxes at the fluid-sediment interface. Basin wide estimates of near-bottom shear stresses can be used to estimate first order nutrient fluxes over a tidal cycle and hence describe general biogeochemical dynamics of the estuary. Future work will include enhanced forcing of currents by

  15. Seasonal occurrence and distribution of submerged aquatic macrophytes in the tidal Potomac River

    USGS Publications Warehouse

    Haramis, G.M.; Carter, V.; Gammon, P.; Hupp, C.

    1979-01-01

    A systematic survey was conducted in the Tidal Potomac River in 1978 to determine the presence, abundance, and phenology of submersed aquatic macrophytes. The survey covered 81.5 km of main river and 59.3 km of tributary on the Maryland shore. Four regions were selected for the study: (1) Piscataway - Mattawoman Creek region (fresh-tidal river), (2) Nanjemoy Creek-Port Tobacco River region (transition zone), (3) Wicomico River region (estuary), and (4) St. Marys River region (estuary). The Wicomico River region was subdivided into fresh tidal river, transition zone and estuary for purposes of date analysis. Data were gathered by sampling each 15 m along transects running perpendicular to shore for a maximum distance of 300 m. Modified oyster tongs were used to sample both plants and benthic soils from an outboard boat. A total of 131 transects were established with a total of approximately 3500 grabs being taken per sampling period. Sampling was initiated in the spring and repeated in the summer and fall. Highest plant diversity and productivity were measured in the transition zone extending from Lower Cedar Point to beyond Maryland Point, a distance of approximately 30 km, and in the transition zone of the Wicomico River above Chaptico Bay. Fresh tidal areas were devoid of plants. The estuary had a sparse growth of horned pondweed (Zannichellia palustris) and widgeon grass (Ruppia maritima) in the spring: horned pondweed was not found in summer or fall. Redhead grass (Potomageton perfoliatus) was the most abundant pondweed; it matured in early summer and died back in mid-to-late summer. Wild celery (Vallisneria americana) and widgeon grass matured in early-to-late fall and were the most abundant plants during that period. Data analysis is being finalized and a publication is in preparation. This research will be continued over the next several seasons as part of the long term USGS effort on the Potomac

  16. Underside from northeast. Waterville Bridge, Spanning Swatara Creek at ...

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

    Underside from northeast. - Waterville Bridge, Spanning Swatara Creek at Appalachian Trail (moved from Little Pine Creek at State Route 44, Waterville, Lycoming County), Green Point, Lebanon County, PA

  17. SANDY CREEK ROADLESS AREA, MISSISSIPPI.

    USGS Publications Warehouse

    Haley, Boyd R.; Bitar, Richard F.

    1984-01-01

    The Sandy Creek Roadless Area includes about 3. 7 sq mi in the southeastern part of Adams County, Mississippi. On the basis of a mineral survey, the area offers little promise for the occurrence of metallic mineral resources but has a probable resource potential for oil and natural gas. It is possible that wells drilled deep enough to penetrate the older reservoirs will encounter significant quantities of oil and natural gas in the roadless area. The deposits of gravel, sand, and clay present in the area could be utilized in the construction industry, but similar deposits elsewhere are much closer to available markets.

  18. Dispersal potential of a tidal river and colonization of a created tidal freshwater marsh

    PubMed Central

    Leck, Mary Allessio

    2012-01-01

    Background and aims A created tidal freshwater wetland, with no extant seed bank, was monitored to evaluate the colonization potential of a tidal river, vegetation and seed bank changes, and also species persistence. Methodology The 32.3-ha mitigation, adjacent to the Delaware River, was completed in 1994. Three sites, with differing completion dates, and three locations (channel edge, midpoint, upland edge) were sampled. From 1995 to 1999, surveys permitted a view of initial dynamics involving soil seed bank density or field vegetation cover, as well as species composition. Vegetation was monitored through 2011, and in 2011 a seed bank survey was also undertaken. Principal results Between 1995 and 1999, 177 species emerged from soil samples, with a maximum of 32.3 ± 1.8 (SE)/sample. Eight species were added in 2011, indicating continuing dispersal and input. Comparing species richness across three sites for midpoint locations, 2011 totals and species/sample were lower (61–90 % and 53–72 %, respectively) than 1998 values. In vegetation plots during the first 5 years, 72 cover species were present. In 2011, there were 44; 14 were new and the majority (13) were woody and part of an overhanging edge canopy. Dispersal was primarily via water. Overall, the trend was towards lower seed bank densities, except for Mikania scandens and Phragmites australis which had higher densities, as well as cover values. Species richness also decreased. Species varied in persistence in the seed bank and vegetation, and among sites and with location. Initial site colonization differences were still apparent in 2011 seed bank samples. While present, Lythrum salicaria did not reduce species richness; Phragmites, in contrast, had substantial impact. Conclusions The single most important change was an increase in Phragmites in the vegetation. Vegetation dynamics are now determined by this species, and the persistent seed bank and continuing dispersal input have little obvious future in

  19. Seasonal dynamics of circulation in Hooghly Estuary and its adjacent coastal oceans

    NASA Astrophysics Data System (ADS)

    Mishra, Shashank Kr.; Nayak, Gourav; Nayak, R. K.; Dadhwal, V. K.

    2016-05-01

    Hooghly is one of the major estuaries in Ganges, the largest and longest river in the Indian subcontinent. The Hooghly estuary is a coastal plain estuary lying approximately between 21°-23° N and 87°-89° E. We used a terrain following ocean model to study tide driven residual circulations, seasonal mean flow patterns and its energetics in the Hooghly estuary and adjacent coastal oceans on the north eastern continental shelf of India. The model is driven by tidal levels at open ocean end and winds at the air-sea interface. The sources of forcing fields for tides were from FES2012, winds from ECMWF. Harmonic analysis is carried out to compute the tidal and non-tidal components of currents and sea level from the model solutions. The de-tidal components were averaged for the entire period of simulation to describe residual and mean-seasonal circulations in the regions. We used tide-gauge, SARAL-ALTIKA along track sea level measurements to evaluate model solutions. Satellite measure Chla were used along with simulated currents to describe important features of the circulations in the region.

  20. Characterization of an Active Thermal Erosion Site, Caribou Creek, Alaska

    NASA Astrophysics Data System (ADS)

    Busey, R.; Bolton, W. R.; Cherry, J. E.; Hinzman, L. D.

    2013-12-01

    The goal of this project is to estimate volume loss of soil over time from this site, provide parameterizations on erodibility of ice rich permafrost and serve as a baseline for future landscape evolution simulations. Located in the zone of discontinuous permafrost, the interior region of Alaska (USA) is home to a large quantity of warm, unstable permafrost that is both high in ice content and has soil temperatures near the freezing point. Much of this permafrost maintains a frozen state despite the general warming air temperature trend in the region due to the presence of a thick insulating organic mat and a dense root network in the upper sub-surface of the soil column. At a rapidly evolving thermo-erosion site, located within the Caribou-Poker Creeks Research Watershed (part of the Bonanza Creek LTER) near Chatanika, Alaska (N65.140, W147.570), the protective organic layer and associated plants were disturbed by an adjacent traditional use trail and the shifting of a groundwater spring. These triggers have led to rapid geomorphological change on the landscape as the soil thaws and sediment is transported into the creek at the valley bottom. Since 2006 (approximately the time of initiation), the thermal erosion has grown to 170 meters length, 3 meters max depth, and 15 meters maximum width. This research combines several data sets: DGPS survey, imagery from an extremely low altitude pole-based remote sensing (3 to 5 meters above ground level), and imagery from an Unmanned Aerial System (UAS) at about 60m altitude.

  1. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draws of the...

  2. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draws of the...

  3. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  4. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  5. 33 CFR 117.543 - Bear Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Bear Creek. 117.543 Section 117.543 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.543 Bear Creek. (a) The draw of the...

  6. 33 CFR 117.335 - Taylor Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Taylor Creek. 117.335 Section 117.335 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.335 Taylor Creek. The draw of US441 bridge, mile...

  7. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... The appropriate maps for determining the boundaries of the Swan Creek viticultural area are three United States Geological Survey (USGS) 1:100,000 scale topographic maps. They are titled: (1) Winston...) Salisbury, North Carolina, 1985, photoinspected 1983. (c) Boundary. The Swan Creek viticultural area...

  8. 33 CFR 117.555 - College Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false College Creek. 117.555 Section 117.555 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.555 College Creek. The draws of...

  9. 33 CFR 117.555 - College Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false College Creek. 117.555 Section 117.555 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.555 College Creek. The draws of...

  10. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  11. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  12. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  13. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  14. 33 CFR 117.324 - Rice Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Rice Creek. 117.324 Section 117.324 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.324 Rice Creek. The CSX Railroad Swingbridge,...

  15. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  16. 33 CFR 117.809 - Tonawanda Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Tonawanda Creek. 117.809 Section 117.809 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.809 Tonawanda Creek. The draw of...

  17. 33 CFR 117.1013 - Kinsale Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Kinsale Creek. 117.1013 Section 117.1013 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1013 Kinsale Creek. The draw of...

  18. 33 CFR 117.1013 - Kinsale Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Kinsale Creek. 117.1013 Section 117.1013 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1013 Kinsale Creek. The draw of...

  19. 33 CFR 117.1013 - Kinsale Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Kinsale Creek. 117.1013 Section 117.1013 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1013 Kinsale Creek. The draw of...

  20. 33 CFR 117.1013 - Kinsale Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Kinsale Creek. 117.1013 Section 117.1013 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Virginia § 117.1013 Kinsale Creek. The draw of...

  1. 33 CFR 117.557 - Curtis Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Curtis Creek. 117.557 Section 117.557 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.557 Curtis Creek. The draw of the I695...

  2. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  3. 33 CFR 117.571 - Spa Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Spa Creek. 117.571 Section 117.571 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.571 Spa Creek. The S181 bridge, mile 4.0,...

  4. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  5. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  6. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  7. 33 CFR 117.331 - Snake Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Snake Creek. 117.331 Section 117.331 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Florida § 117.331 Snake Creek. The draw of the Snake...

  8. Pine Creek Ranch; Annual Report 2002.

    SciTech Connect

    Berry, Mark E.

    2003-02-01

    This report gives information about the following four objectives: OBJECTIVE 1--Gather scientific baseline information for monitoring purposes and to assist in the development of management plans for Pine Creek Ranch; OBJECTIVE 2--Complete and implement management plans; OBJECTIVE 3--Protect, manage and enhance the assets and resources of Pine Creek Ranch; and OBJECTIVE 4--Deliverables.

  9. 33 CFR 117.573 - Stoney Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Stoney Creek. 117.573 Section 117.573 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.573 Stoney Creek. The draw of the Stoney...

  10. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Swan Creek. 9.211 Section... THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.211 Swan Creek. (a) Name. The name of the viticultural area described in this section is “Swan Creek”....

  11. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Swan Creek. 9.211 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.211 Swan Creek. (a) Name. The name of the viticultural area described in this section is “Swan Creek”....

  12. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Swan Creek. 9.211 Section... THE TREASURY ALCOHOL AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.211 Swan Creek. (a) Name. The name of the viticultural area described in this section is “Swan Creek”....

  13. 27 CFR 9.211 - Swan Creek.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Swan Creek. 9.211 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.211 Swan Creek. (a) Name. The name of the viticultural area described in this section is “Swan Creek”....

  14. 33 CFR 117.577 - Weems Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Weems Creek. 117.577 Section 117.577 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.577 Weems Creek. The draw of the S437...

  15. 33 CFR 117.573 - Stoney Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Stoney Creek. 117.573 Section 117.573 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.573 Stoney Creek. The draw of the Stoney...

  16. 33 CFR 117.573 - Stoney Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Stoney Creek. 117.573 Section 117.573 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.573 Stoney Creek. The draw of the Stoney...

  17. 33 CFR 117.577 - Weems Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Weems Creek. 117.577 Section 117.577 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.577 Weems Creek. The draw of the S437...

  18. 33 CFR 117.563 - Marshyhope Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Marshyhope Creek. 117.563 Section 117.563 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.563 Marshyhope Creek. The draw of...

  19. 33 CFR 117.563 - Marshyhope Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Marshyhope Creek. 117.563 Section 117.563 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.563 Marshyhope Creek. The draw of...

  20. 33 CFR 117.577 - Weems Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Weems Creek. 117.577 Section 117.577 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.577 Weems Creek. The draw of the S437...

  1. 33 CFR 117.563 - Marshyhope Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Marshyhope Creek. 117.563 Section 117.563 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.563 Marshyhope Creek. The draw of...

  2. 33 CFR 117.563 - Marshyhope Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Marshyhope Creek. 117.563 Section 117.563 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.563 Marshyhope Creek. The draw of...

  3. 33 CFR 117.563 - Marshyhope Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Marshyhope Creek. 117.563 Section 117.563 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.563 Marshyhope Creek. The draw of...

  4. 33 CFR 117.573 - Stoney Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Stoney Creek. 117.573 Section 117.573 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.573 Stoney Creek. The draw of the Stoney...

  5. 33 CFR 117.573 - Stoney Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Stoney Creek. 117.573 Section 117.573 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.573 Stoney Creek. The draw of the Stoney...

  6. 33 CFR 117.577 - Weems Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Weems Creek. 117.577 Section 117.577 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.577 Weems Creek. The draw of the S437...

  7. 33 CFR 117.577 - Weems Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Weems Creek. 117.577 Section 117.577 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.577 Weems Creek. The draw of the S437...

  8. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  9. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  10. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  11. 33 CFR 117.841 - Smith Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Smith Creek. 117.841 Section 117.841 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements North Carolina § 117.841 Smith Creek. The draw of the...

  12. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  13. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  14. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  15. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  16. 33 CFR 117.917 - Battery Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Battery Creek. 117.917 Section 117.917 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements South Carolina § 117.917 Battery Creek. The draw...

  17. Prediction of CBS tidal evolution

    NASA Astrophysics Data System (ADS)

    Dryomova, G. N.

    The time series of basic processes, accompanying the tidal evolution of star components of Close Binary Systems (CBS) are predicted in the framework of evolutionary stellar models by Claret (2004). The series includes the apsidal motion period, timescale of synchronization of axial rotation of a star with the orbital revolution, the orbit circularization timescale, and the age. Data from the catalogues by Svechnikov & Perevozkina (1999) and by Torres, Andersen, Gimenez (2010) are used for testing the sensitivity of the numerical prediction algorithm.

  18. Dynamical modeling of tidal streams

    SciTech Connect

    Bovy, Jo

    2014-11-01

    I present a new framework for modeling the dynamics of tidal streams. The framework consists of simple models for the initial action-angle distribution of tidal debris, which can be straightforwardly evolved forward in time. Taking advantage of the essentially one-dimensional nature of tidal streams, the transformation to position-velocity coordinates can be linearized and interpolated near a small number of points along the stream, thus allowing for efficient computations of a stream's properties in observable quantities. I illustrate how to calculate the stream's average location (its 'track') in different coordinate systems, how to quickly estimate the dispersion around its track, and how to draw mock stream data. As a generative model, this framework allows one to compute the full probability distribution function and marginalize over or condition it on certain phase-space dimensions as well as convolve it with observational uncertainties. This will be instrumental in proper data analysis of stream data. In addition to providing a computationally efficient practical tool for modeling the dynamics of tidal streams, the action-angle nature of the framework helps elucidate how the observed width of the stream relates to the velocity dispersion or mass of the progenitor, and how the progenitors of 'orphan' streams could be located. The practical usefulness of the proposed framework crucially depends on the ability to calculate action-angle variables for any orbit in any gravitational potential. A novel method for calculating actions, frequencies, and angles in any static potential using a single orbit integration is described in the Appendix.

  19. Tidally-Induced Thermonuclear Supernovae

    SciTech Connect

    Rosswog, S.; Ramirez-Ruiz, E.; Hix, William Raphael

    2009-01-01

    We discuss the results of 3D simulations of tidal disruptions of white dwarfs by moderate-mass black holes as they may exist in the cores of globular clusters or dwarf galaxies. Our simulations follow self-consistently the hydrodynamic and nuclear evolution from the initial parabolic orbit over the disruption to the build-up of an accretion disk around the black hole. For strong enough encounters (pericentre distances smaller than about 1/3 of the tidal radius) the tidal compression is reversed by a shock and finally results in a thermonuclear explosion. These explosions are not restricted to progenitor masses close to the Chandrasekhar limit, we find exploding examples throughout the whole white dwarf mass range. There is, however, a restriction on the masses of the involved black holes: black holes more massive than 2x105M{circle_dot} swallow a typical 0.6M{circle_dot} white dwarf before their tidal forces can overwhelm the star's selfgravity. Therefore, this mechanism is characteristic for black holes of moderate masses. The material that remains bound to the black hole settles into an accretion disk and produces an Xray flare close to the Eddington limit of L{sub Edd} {approx} 10{sup 41}erg/s (Mbh/1000M{circle_dot}), typically lasting for a few months. The combination of a peculiar thermonuclear supernova together with an X-ray flare thus whistle-blows the existence of such moderate-mass black holes. The next generation of wide field space-based instruments should be able to detect such events.

  20. Dynamical Modeling of Tidal Streams

    NASA Astrophysics Data System (ADS)

    Bovy, Jo

    2014-11-01

    I present a new framework for modeling the dynamics of tidal streams. The framework consists of simple models for the initial action-angle distribution of tidal debris, which can be straightforwardly evolved forward in time. Taking advantage of the essentially one-dimensional nature of tidal streams, the transformation to position-velocity coordinates can be linearized and interpolated near a small number of points along the stream, thus allowing for efficient computations of a stream's properties in observable quantities. I illustrate how to calculate the stream's average location (its "track") in different coordinate systems, how to quickly estimate the dispersion around its track, and how to draw mock stream data. As a generative model, this framework allows one to compute the full probability distribution function and marginalize over or condition it on certain phase-space dimensions as well as convolve it with observational uncertainties. This will be instrumental in proper data analysis of stream data. In addition to providing a computationally efficient practical tool for modeling the dynamics of tidal streams, the action-angle nature of the framework helps elucidate how the observed width of the stream relates to the velocity dispersion or mass of the progenitor, and how the progenitors of "orphan" streams could be located. The practical usefulness of the proposed framework crucially depends on the ability to calculate action-angle variables for any orbit in any gravitational potential. A novel method for calculating actions, frequencies, and angles in any static potential using a single orbit integration is described in the Appendix.

  1. Biogeochemistry of dissolved organic matter in an anoxic intertidal creek bank

    NASA Astrophysics Data System (ADS)

    Seidel, Michael; Beck, Melanie; Riedel, Thomas; Waska, Hannelore; Suryaputra, I. G. N. A.; Schnetger, Bernhard; Niggemann, Jutta; Simon, Meinhard; Dittmar, Thorsten

    2014-09-01

    Seawater circulation in permeable coastal sediments is driven by tidal changes in hydraulic gradients. The resulting submarine groundwater discharge is a source of nutrients and dissolved organic matter (DOM) to the water column. Yet, little is known about the cycling of DOM within tidal sediments, because the molecular DOM characterization remains analytically challenging. One technique that can dissect the multitude of molecules in DOM is ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). To aim at a high resolution DOM analysis we study the seasonal turnover and marine and terrestrial sources of DOM in an intertidal creek bank of the southern North Sea down to 3 m depth and link the biogeochemical processes to FT-ICR-MS data and the analyses of inorganic porewater chemistry, δ13C of solid-phase extracted dissolved organic carbon (SPE-DOC), dissolved black carbon (DBC) and dissolved carbohydrates (DCHO). Increasing concentrations of dissolved Fe, Mn, P, total alkalinity, dissolved nitrogen, DOC and a concomitant decrease of sulfate along the seawater circulation path from the upper tidal flat to the tidal flat margin indicate continuous microbial activity. The relative increase of Si concentrations, unsaturated aliphatics, peptide molecular formulae and isotopically more 13C-enriched SPE-DOC towards the tidal flat margin suggests that remineralization processes mobilize DOM from buried algal (diatoms) and microbial biomass. Porewater in sediments <100 cm depth contains 13C-depleted SPE-DOC and highly unsaturated compounds which are probably derived from eroded peats, suggesting rapid removal of bioavailable marine DOM such as DCHO from the water column and selective enrichment of terrestrial DOM. DBC concentrations are highest in the discharging porewater close to the tidal creek suggesting that the intertidal flat is an important DBC source to the coastal ocean. Porewater DOM accumulating at the low water line is

  2. Palynology of the Vermillion Creek coal bed and associated strata

    SciTech Connect

    Nichols, D.J.

    1987-01-01

    Fifty-four species of spores, pollen, fungi, and algal palynomorphs were identified from the Vermillion Creek coal bed and associated strata, including underlying and overlying deposits and partings within the coal. The stratigraphic distribution and relative abundances of these plant microfossils were determined in samples from three cores. The palynomorph assemblage, which is late early Eocene in age, includes 8 species of pterophyte spores, 4 species of gymnosperm pollen, 39 species of angiosperm pollen, 2 species of algal coenobia or cysts, and 1 species of fungal spore. The assemblage is dominated by the pollen species Platycarya paltycaryoides and Arecipites tenuiexinous. Ten species appear to have biostratigraphic importance, based on their stratigraphic ranges in the Rocky Mountain region. The record of their occurrence in a well-dated stratigraphic section is a contribution to Tertiary biostratigraphy in the central Rockies. Palynologic evidence supplements stratigraphic, sedimentologic, geochemical, coal petrographic and other paleontologic evidence on the nature of the depositional environment. The Vermillion Creek coal was deposited in a paludal environment adjacent to a nonsaline lacustrine system. Evidence from botanical affinities of palynomorph species and habitats of living relatives indicates that the region had a moist subtropical climate in late early Eocene time.

  3. Water resources of the Sycamore Creek watershed, Maricopa County, Arizona

    USGS Publications Warehouse

    Thomsen, B.W.; Schumann, Herbert H.

    1969-01-01

    The Sycamore Creek watershed is representative of many small watersheds in the Southwest where much of the streamflow originates in the mountainous areas and disappears rather quickly into the alluvial deposits adjacent to the mountains. Five years of .streamflow records from the Sycamore Creek watershed show that an average annual water yield of 6,110 acre-feet was obtained from the 165 square miles (105,000 acres) of the upper hard-rock mountain area, which receives an average annual precipitation of about 20 inches. Only a small percentage of the ,annual water yield, however, reaches the Verde River as surface flow over the 9-mile reach of the alluvial channel below the mountain front. Flows must be more ,than 200 cubic feet per second to reach the river; flows less than this rate disappear into the 1,ower alluvial area and are stored temporarily in the ground-Water reservoir : most of this water is released as ground-water discharge to the Verde River at a relatively constant rate of about 4,000 acre-feet per year. Evapotranspiration losses in the lower alluvial area are controlled by the depth of the water table and averaged about 1,500 acre-feet per year.

  4. ARRAY OPTIMIZATION FOR TIDAL ENERGY EXTRACTION IN A TIDAL CHANNEL – A NUMERICAL MODELING ANALYSIS

    SciTech Connect

    Yang, Zhaoqing; Wang, Taiping; Copping, Andrea

    2014-04-18

    This paper presents an application of a hydrodynamic model to simulate tidal energy extraction in a tidal dominated estuary in the Pacific Northwest coast. A series of numerical experiments were carried out to simulate tidal energy extraction with different turbine array configurations, including location, spacing and array size. Preliminary model results suggest that array optimization for tidal energy extraction in a real-world site is a very complex process that requires consideration of multiple factors. Numerical models can be used effectively to assist turbine siting and array arrangement in a tidal turbine farm for tidal energy extraction.

  5. Tidal Locking Of The Earth

    NASA Astrophysics Data System (ADS)

    Koohafkan, Michael

    2006-05-01

    The Moon's orbit and spin period are nearly synchronized, or tidally locked. Could the Moon's orbit and the Earth's spin eventually synchronize as well? The Moon's gravitational pull on the Earth produces tides in our oceans, and tidal friction gradually lengthens our days. Less obvious gravitational interactions between the Earth and Moon may also have effects on Earth's spin. The Earth is slightly distorted into an egg-like shape, and the torque exerted by the Moon on our equatorial bulge slowly changes the tilt of our spin axis. How do effects such as these change as the Moon drifts away from Earth? I will examine gravitational interactions between Earth and Moon to learn how they contribute to the deceleration of the Earth's rotation. My goal is to determine the amount of time it would take for the Earth's rotational speed to decelerate until the period of a single rotation matches the period of the Moon's orbit around Earth -- when the Earth is ``tidally locked'' with the Moon. I aim to derive a general mathematical expression for the rotational deceleration of the Earth due to Moon's gravitational influences.

  6. North American tidal power prospects

    NASA Astrophysics Data System (ADS)

    Wayne, W. W., Jr.

    1981-07-01

    Prospects for North American tidal power electrical generation are reviewed. Studies by the US Army Corps of Engineers of 90 possible generation schemes in Cobscook Bay, ME, indicated that maximum power generation rather than dependable capacity was the most economic method. Construction cost estimates for 15 MW bulb units in a single effect mode from basin to the sea are provided; five projects were considered ranging from 110-160 MW. Additional tidal power installations are examined for: Half-Moon Cove, ME (12 MW, 18 ft tide); Cook Inlet, AK, which is shown to pose severe environmental and engineering problems due to fish migration, earthquake hazards, and 300 ft deep silt deposits; and the Bay of Fundy, Canada. This last has a 17.8 MW plant under construction in a 29 ft maximum tide area. Other tidal projects of the Maritime Provinces are reviewed, and it is noted that previous economic evaluations based on an oil price of $16/barrel are in need of revision.

  7. Workshop on Stellar Tidal Disruption

    NASA Astrophysics Data System (ADS)

    Farrar, Glennys R.

    2012-04-01

    The past year has seen major advances in the observational status of Stellar Tidal Disruption, with the discovery of two strong optical candidates in archived SDSS data and the real-time X-ray detection of Swift J1644+57, plus rapid radio and optical follow-up establishing it as a probable Tidal Disruption Flare (TDF) in ``blazar mode''. These observations motivated a workshop devoted to discussion of such events and of the theory of their emission and flare rate. Observational contributions included a presentation of Swift J2058+05 (a possible second example of a TDF in blazar mode), reports on the late-time evolution and X-ray variability of the two Swift events, and a proposal that additional candidates may be evidenced by spectral signatures in SDSS. Theory presentations included models of radio emission, theory of light curves and the proposal that GRB101225A may be the Galactic tidal disruption of a neutron star, an interpretation of Swift J1644+57 as due to the disruption of a white dwarf instead of main-sequence star, calculation of the dependence of the TDF rate on the spin of the black hole, and analysis of the SDSS events, fitting their SEDs to profiles of thoretical emission from accretion disks and showing that their luminosity and rate are consistent with the proposal that TDEs can be responsible for UHECR acceleration.

  8. Analysis of Ground-Water Flow in the Madison Aquifer using Fluorescent Dyes Injected in Spring Creek and Rapid Creek near Rapid City, South Dakota, 2003-04

    USGS Publications Warehouse

    Putnam, Larry D.; Long, Andrew J.

    2007-01-01

    , which is located adjacent to the loss zone, was similar to the concentration in the stream. Fluorescein arrived at well NON (injection at site S1), which is located about 2 miles northeast of the loss zone, within about 1.6 days, and the maximum concentration was 44 ug/L. For injection at site S4, when streamflow was about 12 ft3/s, fluorescein was detected in samples from six wells and time to first arrival ranged from 0.2 to 16 days. Following injection at site S4 in 2004, the length of time that dye remained in the capture zone of well NON, which is located approximately 2 miles from the loss zone, was almost an order of magnitude greater than in 2003. For injection at site R1, Rhodamine WT was detected at well DRU and spring TI-SP with time to first arrival of about 0.5 and 1.1 days and maximum concentrations of 6.2 and 0.91 ug/L, respectively. Well DRU and spring TI-SP are located near the center of the Rapid Creek loss zone where the creek has a large meander. Measurable concentrations were observed for spring TI-SP as many as 109 days after the dye injection. The direction of a conduit flow path in the Spring Creek area was to the northeast with ground-water velocities that ranged from 770 to 6,500 feet per day. In the Rapid Creek loss zone, a conduit flow path east of the loss zone was not evident from the dye injection.

  9. Hydrology of the Johnson Creek Basin, Oregon

    USGS Publications Warehouse

    Lee, Karl K.; Snyder, Daniel T.

    2009-01-01

    The Johnson Creek basin is an important resource in the Portland, Oregon, metropolitan area. Johnson Creek forms a wildlife and recreational corridor through densely populated areas of the cities of Milwaukie, Portland, and Gresham, and rural and agricultural areas of Multnomah and Clackamas Counties. The basin has changed as a result of agricultural and urban development, stream channelization, and construction of roads, drains, and other features characteristic of human occupation. Flooding of Johnson Creek is a concern for the public and for water management officials. The interaction of the groundwater and surface-water systems in the Johnson Creek basin also is important. The occurrence of flooding from high groundwater discharge and from a rising water table prompted this study. As the Portland metropolitan area continues to grow, human-induced effects on streams in the Johnson Creek basin will continue. This report provides information on the groundwater and surface-water systems over a range of hydrologic conditions, as well as the interaction these of systems, and will aid in management of water resources in the area. High and low flows of Crystal Springs Creek, a tributary to Johnson Creek, were explained by streamflow and groundwater levels collected for this study, and results from previous studies. High flows of Crystal Springs Creek began in summer 1996, and did not diminish until 2000. Low streamflow of Crystal Springs Creek occurred in 2005. Flow of Crystal Springs Creek related to water-level fluctuations in a nearby well, enabling prediction of streamflow based on groundwater level. Holgate Lake is an ephemeral lake in Southeast Portland that has inundated residential areas several times since the 1940s. The water-surface elevation of the lake closely tracked the elevation of the water table in a nearby well, indicating that the occurrence of the lake is an expression of the water table. Antecedent conditions of the groundwater level and autumn

  10. TIDAL FRICTION AND TIDAL LAGGING. APPLICABILITY LIMITATIONS OF A POPULAR FORMULA FOR THE TIDAL TORQUE

    SciTech Connect

    Efroimsky, Michael; Makarov, Valeri V. E-mail: vvm@usno.navy.mil

    2013-02-10

    Tidal torques play a key role in rotational dynamics of celestial bodies. They govern these bodies' tidal despinning and also participate in the subtle process of entrapment of these bodies into spin-orbit resonances. This makes tidal torques directly relevant to the studies of habitability of planets and their moons. Our work begins with an explanation of how friction and lagging should be built into the theory of bodily tides. Although much of this material can be found in various publications, a short but self-consistent summary on the topic has been lacking in the hitherto literature, and we are filling the gap. After these preparations, we address a popular concise formula for the tidal torque, which is often used in the literature, for planets or stars. We explain why the derivation of this expression, offered in the paper by Goldreich and in the books by Kaula (Equation (4.5.29)) and Murray and Dermott (Equation (4.159)), implicitly sets the time lag to be frequency independent. Accordingly, the ensuing expression for the torque can be applied only to bodies having a very special (and very hypothetical) rheology which makes the time lag frequency independent, i.e., the same for all Fourier modes in the spectrum of tide. This expression for the torque should not be used for bodies of other rheologies. Specifically, the expression cannot be combined with an extra assertion of the geometric lag being constant, because at finite eccentricities the said assumption is incompatible with the constant-time-lag condition.

  11. Tidal Friction and Tidal Lagging. Applicability Limitations of a Popular Formula for the Tidal Torque

    NASA Astrophysics Data System (ADS)

    Efroimsky, Michael; Makarov, Valeri V.

    2013-02-01

    Tidal torques play a key role in rotational dynamics of celestial bodies. They govern these bodies' tidal despinning and also participate in the subtle process of entrapment of these bodies into spin-orbit resonances. This makes tidal torques directly relevant to the studies of habitability of planets and their moons. Our work begins with an explanation of how friction and lagging should be built into the theory of bodily tides. Although much of this material can be found in various publications, a short but self-consistent summary on the topic has been lacking in the hitherto literature, and we are filling the gap. After these preparations, we address a popular concise formula for the tidal torque, which is often used in the literature, for planets or stars. We explain why the derivation of this expression, offered in the paper by Goldreich and in the books by Kaula (Equation (4.5.29)) and Murray & Dermott (Equation (4.159)), implicitly sets the time lag to be frequency independent. Accordingly, the ensuing expression for the torque can be applied only to bodies having a very special (and very hypothetical) rheology which makes the time lag frequency independent, i.e., the same for all Fourier modes in the spectrum of tide. This expression for the torque should not be used for bodies of other rheologies. Specifically, the expression cannot be combined with an extra assertion of the geometric lag being constant, because at finite eccentricities the said assumption is incompatible with the constant-time-lag condition.

  12. Tidal acceleration of black holes and superradiance

    NASA Astrophysics Data System (ADS)

    Cardoso, Vitor; Pani, Paolo

    2013-02-01

    Tidal effects have long ago locked the Moon in a synchronous rotation with the Earth and progressively increase the Earth-Moon distance. This ‘tidal acceleration’ hinges on dissipation. Binaries containing black holes may also be tidally accelerated, dissipation being caused by the event horizon—a flexible, viscous one-way membrane. In fact, this process is known for many years under a different guise: superradiance. Here, we provide compelling evidence for a strong connection between tidal acceleration and superradiant scattering around spinning black holes. In general relativity, tidal acceleration is obscured by the gravitational-wave emission. However, when coupling to light scalar degrees of freedom is allowed, an induced dipole moment produces a ‘polarization acceleration’, which might be orders of magnitude stronger than tidal quadrupolar effects. Consequences for optical and gravitational-wave observations are intriguing and it is not impossible that imprints of such a mechanism have already been observed.

  13. Gravitoelectromagnetic analogy based on tidal tensors

    SciTech Connect

    Costa, L. Filipe O.; Herdeiro, Carlos A. R.

    2008-07-15

    We propose a new approach to a physical analogy between general relativity and electromagnetism, based on tidal tensors of both theories. Using this approach we write a covariant form for the gravitational analogues of the Maxwell equations, which makes transparent both the similarities and key differences between the two interactions. The following realizations of the analogy are given. The first one matches linearized gravitational tidal tensors to exact electromagnetic tidal tensors in Minkowski spacetime. The second one matches exact magnetic gravitational tidal tensors for ultrastationary metrics to exact magnetic tidal tensors of electromagnetism in curved spaces. In the third we show that our approach leads to a two-step exact derivation of Papapetrou's equation describing the force exerted on a spinning test particle. Analogous scalar invariants built from tidal tensors of both theories are also discussed.

  14. TIDAL NOVAE IN COMPACT BINARY WHITE DWARFS

    SciTech Connect

    Fuller, Jim; Lai Dong

    2012-09-01

    Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in the inner stellar envelope and the dissipation of these waves in the outer envelope. As the binary orbit decays, the WDs are synchronized from outside in (with the envelope synchronized first, followed by the core). We examine the deposition of tidal heat in the envelope of a carbon-oxygen WD and study how such tidal heating affects the structure and evolution of the WD. We show that significant tidal heating can occur in the star's degenerate hydrogen layer. This layer heats up faster than it cools, triggering runaway nuclear fusion. Such 'tidal novae' may occur in all WD binaries containing a CO WD, at orbital periods between 5 minutes and 20 minutes, and precede the final merger by 10{sup 5}-10{sup 6} years.

  15. Sedimentation and response to sea-level rise of a restored marsh with reduced tidal exchange: Comparison with a natural tidal marsh

    USGS Publications Warehouse

    Vandenbruwaene, W.; Maris, T.; Cahoon, D.R.; Meire, P.; Temmerman, S.

    2011-01-01

    Along coasts and estuaries, formerly embanked land is increasingly restored into tidal marshes in order to re-establish valuable ecosystem services, such as buffering against flooding. Along the Scheldt estuary (Belgium), tidal marshes are restored on embanked land by allowing a controlled reduced tide (CRT) into a constructed basin, through a culvert in the embankment. In this way tidal water levels are significantly lowered (ca. 3 m) so that a CRT marsh can develop on formerly embanked land with a ca. 3 m lower elevation than the natural tidal marshes. In this study we compared the long-term change in elevation (ΔE) within a CRT marsh and adjacent natural tidal marsh. Over a period of 4 years, the observed spatio-temporal variations in ΔE rate were related to variations in inundation depth, and this relationship was not significantly different for the CRT marsh and natural tidal marsh. A model was developed to simulate the ΔE over the next century. (1) Under a scenario without mean high water level (MHWL) rise in the estuary, the model shows that the marsh elevation-ΔE feedback that is typical for a natural tidal marsh (i.e. rising marsh elevation results in decreasing inundation depth and therefore a decreasing increase in elevation) is absent in the basin of the CRT marsh. This is because tidal exchange of water volumes between the estuary and CRT marsh are independent from the CRT marsh elevation but dependent on the culvert dimensions. Thus the volume of water entering the CRT remains constant regardless of the marsh elevation. Consequently the CRT MHWL follows the increase in CRT surface elevation, resulting after 75 years in a 2–2.5 times larger elevation gain in the CRT marsh, and a faster reduction of spatial elevation differences. (2) Under a scenario of constant MHWL rise (historical rate of 1.5 cm a-1), the equilibrium elevation (relative to MHWL) is 0.13 m lower in the CRT marsh and is reached almost 2 times faster. (3) Under a scenario of

  16. Stratification and loading of fecal indicator bacteria (FIB) in a tidally muted urban salt marsh.

    PubMed

    Johnston, Karina K; Dorsey, John H; Saez, Jose A

    2015-03-01

    Stratification and loading of fecal indicator bacteria (FIB) were assessed in the main tidal channel of the Ballona Wetlands, an urban salt marsh receiving muted tidal flows, to (1) determine FIB concentration versus loading within the water column at differing tidal flows, (2) identify associations of FIB with other water quality parameters, and (3) compare wetland FIB concentrations to the adjacent estuary. Sampling was conducted four times during spring-tide events; samples were analyzed for FIB and turbidity (NTU) four times over a tidal cycle at pre-allocated depths, depending on the water level. Additional water quality parameters measured included temperature, salinity, oxygen, and pH. Loadings were calculated by integrating the stratified FIB concentrations with water column cross-sectional volumes corresponding to each depth. Enterococci and Escherichia coli were stratified both by concentration and loading, although these variables portrayed different patterns over a tidal cycle. Greatest concentrations occurred in surface to mid-strata levels, during flood tides when contaminated water flowed in from the estuary, and during ebb flows when sediments were suspended. Loading was greatest during flood flows and diminished during low tide periods. FIB concentrations within the estuary often were significantly greater than those within the wetland tide channel, supporting previous studies that the wetlands act as a sink for FIB. For public health water quality monitoring, these results indicate that more accurate estimates of FIB concentrations would be obtained by sampling a number of points within a water column rather than relying only on single surface samples.

  17. Flood discharges and hydraulics near the mouths of Wolf Creek, Craig Branch, Manns Creek, Dunloup Creek, and Mill Creek in the New River Gorge National River, West Virginia

    USGS Publications Warehouse

    Wiley, J.B.

    1994-01-01

    The U.S. Geological Survey, in cooperation with the National Park Service, studied the frequency and magnitude of flooding near the mouths of five tributaries to the New River in the New River Gorge National River. The 100-year peak discharge at each tributary was determined from regional frequency equations. The 100-year discharge at Wolf Creek, Craig Branch, Manns Creek, Dunloup Creek, and Mill Creek was 3,400 cubic feet per second, 640 cubic feet per second, 8,200 cubic feet per second, 7,100 cubic feet per second, and 9,400 cubic feet per second, respectively. Flood elevations for each tributary were determined by application of a steady-state, one-dimensional flow model. Manning's roughness coefficients for the stream channels ranged from 0.040 to 0.100. Bridges that would be unable to contain the 100-year flood within the bridge opening included: the State Highway 82 bridge on Wolf Creek, the second Fayette County Highway 25 bridge upstream from the confluence with New River on Dunloup Creek, and an abandoned log bridge on Mill Creek.

  18. Tidally dominated sediment dispersal offshore of a small mountainous river: Elwha River, Washington State

    NASA Astrophysics Data System (ADS)

    Eidam, E. F.; Ogston, A. S.; Nittrouer, C. A.; Warrick, J. A.

    2016-03-01

    Sediment supplied by small mountainous rivers (SMRs) represents a major fraction of the global ocean sediment budget. Studies from the past two decades have shown that much of this sediment is dispersed by episodic wind and wave energy along storm-dominated coasts. In tidally dominated environments, however, different transport styles and deposits may result from persistent tidal dispersal. This study investigates episodic sediment releases generated by dam removal from a SMR in Washington State, in order to evaluate the mechanics of tidally dominated sediment dispersal in an energetic marine environment. The results indicate that asymmetric tidal currents with peak magnitudes of ∼50 to >80 cm/s produce daily sediment export in the direction of the dominant tidal phase (i.e., the semi-diurnal phase with faster currents and longer duration), resulting in dispersal of fluvially derived fine sediment to distal sinks. These effects are observed throughout all seasons in the presence or absence of wave events. During the first two years of dam removal, more than 8 million tonnes of sediment were discharged to the coast. The net result was little to no change in grain size at 10-60 m water depth across >70% of the seabed offshore of the river mouth. Over the remaining ∼2 to 3 km2 of the subaqueous delta, several cm of mud and sand accumulated in a sheltered coastal embayment adjacent to the river mouth. These results demonstrate that SMR discharge events may form patchy, isolated deposits-or even no deposits-along coastlines with strong tidal currents, in contrast to the mid-shelf mud belts formed on storm-dominated shelves. Over longer timescales, knowledge of the erosional capacity of local and regional tidal currents may be key to interpreting the terrestrial event record preserved in (or possibly excluded from) marine SMR deposits.

  19. Flooding and sedimentation in Wheeling Creek basin, Belmont County, Ohio

    USGS Publications Warehouse

    Kolva, J.R.; Koltun, G.F.

    1987-01-01

    The Wheeling Creek basin, which is located primarily in Belmont County, Ohio, experienced three damaging floods and four less severe floods during the 29-month period from February 1979 through June 1981. Residents of the basin became concerned about factors that could have affected the severity and frequency of out-of-bank floods. In response to those concerns, the U.S. Geological Survey, in cooperation with the Ohio Department of Natural Resources, undertook a study to estimate peak discharges and recurrence intervals for the seven floods of interest, provide information on current and historical mining-related stream-channel fill or scour, and examine storm-period subbasin contributions to the sediment load in Wheeling Creek. Streamflow data for adjacent basins, rainfall data, and, in two cases, flood-profile data were used in conjunction with streamflow data subsequently collected on Wheeling Creek to provide estimates of peak discharge for the seven floods that occurred from February 1979 through June 1981. Estimates of recurrence intervals were assigned to the Peak discharges on the basin of regional regression equations that relate selected basin characteristics to peak discharge with fixed recurrence intervals. These estimates indicate that a statistically unusual number of floods with recurrence intervals of 2 years or more occurred within that time period. Three cross sections located on Wheeling Creek and four located on tributaries were established and surveyed quarterly for approximately 2 years. No evidence of appreciable stream-channel fill or scour was observed at any of the cross sections, although minor profile changes were apparent at some locations. Attempts were made to obtain historical cross-section profile data for comparison with current cross-section profiles; however, no usable data were found. Excavations of stream-bottom materials were made near the three main-stem cross-section locations and near the mouth of Jug Run. The bottom

  20. Calculating lunar retreat rates using tidal rhythmites

    USGS Publications Warehouse

    Kvale, E.P.; Johnson, H.W.; Sonett, C.P.; Archer, A.W.; Zawistoski, A.N.N.

    1999-01-01

    Tidal rhythmites are small-scale sedimenta??r}- structures that can preserve a hierarchy of astronomically induced tidal periods. They can also preserve a record of periodic nontidal sedimentation. If properly interpreted and understood, tidal rhjthmites can be an important component of paleoastronomy and can be used to extract information on ancient lunar orbital dynamics including changes in Earth-Moon distance through geologic time. Herein we present techniques that can be used to calculate ancient Earth-Moon distances. Each of these techniques, when used on a modern high-tide data set, results in calculated estimates of lunar orbital periods and an EarthMoon distance that fall well within 1 percent of the actual values. Comparisons to results from modern tidal data indicate that ancient tidal rhythmite data as short as 4 months can provide suitable estimates of lunar orbital periods if these tidal records are complete. An understanding of basic tidal theory allows for the evaluation of completeness of the ancient tidal record as derived from an analysis of tidal rhythmites. Utilizing the techniques presented herein, it appears from the rock record that lunar orbital retreat slowed sometime during the midPaleozoic. Copyright ??1999, SEPM (Society for Sedimentary Geology).

  1. Tidal friction in close-in planets

    NASA Astrophysics Data System (ADS)

    Rodríguez, Adrián; Ferraz-Mello, Sylvio; Hussmann, Hauke

    2008-05-01

    We use Darwin's theory (Darwin, 1880) to derive the main results on the orbital and rotational evolution of a close-in companion (exoplanet or planetary satellite) due to tidal friction. The given results do not depend on any assumption linking the tidal lags to the frequencies of the corresponding tide harmonics (except that equal frequency harmonics are assumed to span equal lags). Emphasis is given to the study of the synchronization of the planetary rotation in the two possible final states for a non-zero eccentricity : (1) the super-synchronous stationary rotation resulting from the vanishing of the average tidal torque; (2) the capture into a 1:1 spin-orbit resonance (true synchronization), which is only possible if an additional torque exists acting in opposition to the tidal torque. Results are given under the assumption that this additional torque is produced by a non-tidal permanent equatorial asymmetry of the planet. The indirect tidal effects and some non-tidal effects due to that asymmetry are considered. For sake of comparison with other works, the results obtained when tidal lags are assumed proportional to the corresponding tidal wave frequencies are also given.

  2. 23. VIEW SHOWING HIGH WATER IN ROWDY CREEK WITH COLLAPSED ...

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

    23. VIEW SHOWING HIGH WATER IN ROWDY CREEK WITH COLLAPSED SECTION IN CREEK, LOOKING NORTH TO SOUTH FROM END OF UNCOLLAPSED SECTION Winter 1931-32 - Rowdy Creek Bridge, Spanning Rowdy Creek at Fred Haight Drive, Smith River, Del Norte County, CA

  3. 77 FR 10960 - Drawbridge Operation Regulation; Snake Creek, Islamorada, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-24

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulation; Snake Creek, Islamorada, FL AGENCY... of Snake Creek Bridge, mile 0.5, across Snake Creek, in Islamorada, Florida. The regulation is set... Sheriff's Office has requested a temporary modification to the operating schedule of Snake Creek Bridge...

  4. Los Creek Roadless Area, California

    SciTech Connect

    Muffler, L.J.P.; Campbell, H.W.

    1984-01-01

    Geologic and mineral-resource investigations in 1981-1982 by the USGS and USBM identified no mineral-resource potential in the Lost Creek Roadless Area. Sand and gravel have been mined from alluvial flood-plain deposits less than 1 mi outside the roadless area; these deposits are likely to extend into the roadless area beneath a Holocene basalt flow that may be as much as 40 ft thick. An oil and gas lease application which includes the eastern portion of the roadless area is pending. Abundant basalt in the area can be crushed and used as aggregate, but similar deposits of volcanic cinders or sand and gravel in more favorable locations are available outside the roadless area closer to major markets. No indication of coal or geothermal energy resources was identified.

  5. LOST CREEK ROADLESS AREA, CALIFORNIA.

    USGS Publications Warehouse

    Muffler, L.J. Patrick; Campbell, Harry W.

    1984-01-01

    Geologic and mineral-resource investigations identified no mineral-resource potential in the Lost Creek Roadless Area, California. Sand and gravel have been mined from alluvial flood-plain deposits less than 1 mi outside the roadless area; these deposits are likely to extend into the roadless area beneath a Holocene basalt flow that may be as much as 40 ft thick. An oil and gas lease application which includes the eastern portion of the roadless area is pending. Abundant basalt in the area can be crushed and used as aggregate, but similar deposits of volcanic cinders or sand and gravel in more favorable locations are available outside the roadless area closer to major markets. No indication of coal or geothermal energy resources was identified.

  6. Snow Distribution Patterns in Clearings and Adjacent Forest

    NASA Astrophysics Data System (ADS)

    Golding, Douglas L.; Swanson, Robert H.

    1986-12-01

    Snow accumulation patterns were determined for clearings and adjacent forest at Marmot Creek experimental watershed and James River, Alberta. At maximum accumulation snow water equivalent (SWE) was greater in clearings than in forest whether clearings were large, as in 8- to 13-ha blocks where SWE averaged 20% more than in the forest, or small as in the ¼ to 6-H (height) diameter circular clearings where SWE was 13-45% greater than in the forest. SWE was 42 to 52% less in north than in south sectors of 2-6 H clearings. These differences increased with clearing size and time since beginning of accumulation period and are caused by snow ablation (melt and evaporation), a function of direct solar radiation reaching the snowpack. In such situations the snow that has accumulated on the ground cannot be considered a measure of the snow that has actually fallen there. For water balances and hydrologic modeling, snow measurements in partially cleared watersheds must be adjusted for temporal and spatial factors specific to the watershed.

  7. Tidal and seasonal variations in the quantity and composition of seston in a North American, mid-Atlantic saltmarsh

    NASA Astrophysics Data System (ADS)

    Huang, S.-C.; Kreeger, D. A.; Newell, R. I. E.

    2003-03-01

    We determined the concentration of seston, particulate organic matter, and biological components (chlorophyll a, bacteria, and heterotrophic nanoflagellates) for <25 μm size fraction seston over five seasons in Canary Creek saltmarsh, Delaware Bay, USA. This material is the potential food resource for suspension-feeding ribbed mussels, Geukensia demissa, that inhabit the marsh intertidal zone. For eight tidal cycles each season we collected water six times at hourly intervals from mid-flood tide to mid-ebb tide. Although the concentration of seston did not vary seasonally, there were significant seasonal variations (analysis of variance, P<0.05) in seston components, with chlorophyll a concentration being highest in May and bacteria and heterotrophic nanoflagellates most abundant in August. Seston composition also varied within each tidal cycle with a magnitude as great as the seasonal variation. We conclude that ribbed mussels are subject to an unpredictable food supply that varies in composition and concentration on the order of hours and days. In contrast to the pronounced temporal changes, seston characteristics did not differ significantly among sampling locations within the marsh, or between samples collected close to the sediment surface and from the upper water column. Resuspension of sediment particles caused by tidal flow was not evident in tidal creeks and there were no dominant patterns in total seston concentration corresponding to tidal stages (flood tide, high slack water, and ebb tide) over the five sampling months. The abundance of biological components in the seston, including chlorophyll a, bacteria, and heterotrophic nanoflagellates, were significantly greater during high flood tide and high slack water than during ebb tide. The decline of biological components, particularly chlorophyll a in the ebb tide, indicates that this temperate saltmarsh imported organic material produced in the Delaware estuary.

  8. Panther Creek, Idaho, Habitat Rehabilitation, Final Report.

    SciTech Connect

    Reiser, Dudley W.

    1986-01-01

    The purpose of the project was to achieve full chinook salmon and steelhead trout production in the Panther Creek, Idaho, basin. Plans were developed to eliminate the sources of toxic effluent entering Panther Creek. Operation of a cobalt-copper mine since the 1930's has resulted in acid, metal-bearing drainage entering the watershed from underground workings and tailings piles. The report discusses plans for eliminating and/or treating the effluent to rehabilitate the water quality of Panther Creek and allow the reestablishment of salmon and trout spawning runs. (ACR)

  9. Steel Creek wildlife: L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1987

    SciTech Connect

    Giffin, M.A.; Patterson, K.K.

    1988-03-01

    Reptile and amphibian populations in Steel Creek below L-Lake were assessed in monthly or quarterly sampling programs. Thirty-eight species of reptiles or amphibians were collected during 1987 in the Steel Creek corridor below the L-Lake impoundment, and in the delta and channel. Juvenile turtles and alligators, and larval amphibians were observed or collected during the study, indicating continued reproduction in Steel Creek. The reptile and amphibian populations in Steel Creek show no indication of any effect due to the impoundment of the lake or the operation of L-Reactor. Waterfowl and associated birds in Steel Creek below L-Lake were observed, in conjunction with other sampling programs, during winter--spring and fall--winter migrations. Nine species of waterfowl and five species of associated birds were observed in 1987 in the Steel Creek corridor below the L-Lake impoundment and in the delta and channel.

  10. Flood of August 27-28, 1977, West Cache Creek and Blue Beaver Creek, southwestern Oklahoma

    USGS Publications Warehouse

    Corley, Robert K.; Huntzinger, Thomas L.

    1979-01-01

    This report documents a major storm which occurred August 27-28, 1977, in southwest Oklahoma near the communities of Cache and Faxon, OK. Blue Beaver Creek and West Cache Creek and their tributaries experienced extensive flooding that caused an estimated $1 million in damages. Reported rainfall amounts of 8 to 12 inches in 6 hours indicate the storm had a frequency in excess of the 100-year rainfall. Peak discharges on Blue Beaver Creek near Cache and West Cache Creek near Faxon were 13,500 cubic feet per second and 45,700 cubic feet per second respectively. The estimated flood frequency was in excess of 100 years on Blue Beaver Creek and in excess of 50 years on West Cache Creek. Unit runoff on small basins were in excess of 2000 cubic feet per second per square mile. Surveyed highwater marks were used to map the flooded area. (USGS)

  11. Transport and deposition of river sediment in the Changjiang estuary and adjacent continental shelf

    USGS Publications Warehouse

    Milliman, John D.; Huang-ting, S.; Zuo-sheng, Y.; Mead, R.H.

    1985-01-01

    Hydrographic observations, suspended-sediment measurements, and historical data indicate transport paths and sinks for sediment within the Changjiang estuary and adjacent shelf. Most of the sediment transported by the Changjiang to the ocean is carried through the North Channel of the South Branch. Sediment transport is directly related to river stage, but tidal phase (spring vs neap tides) also plays an important role. An estimated 40% of the sediment load in the river is deposited in the estuary, mostly in and seaward of the South Channel. The remaining sediment is deposited directly offshore during flood seasons, but much is resuspended and carried southward by subsequent winter storms. ?? 1985.

  12. Social Contexts of Development in Natural Outdoor Environments: Children's Motor Activities, Personal Challenges and Peer Interactions at the River and the Creek

    ERIC Educational Resources Information Center

    McClain, Cara; Vandermaas-Peeler, Maureen

    2016-01-01

    This study examined the influence of spending time outdoors on young children's physical and socioemotional development. We observed preschoolers' activities in two naturally provisioned outdoor environments over the course of one year. Eleven preschoolers were videotaped continuously for 16 days at a local river and 9 days at a creek adjacent to…

  13. 78 FR 5798 - Grouse Creek Wind Park, LLC, Grouse Creek Wind Park II, LLC; Notice of Petition for Enforcement

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Grouse Creek Wind Park, LLC, Grouse Creek Wind Park II, LLC; Notice of... Utility Regulatory Policies Act of 1978 (PURPA), Grouse Creek Wind Park, LLC and Grouse Creek Wind Park...

  14. River discharge controlling a tidal delta: the interplay between monsoon input and tidal reworking in SW Bangladesh

    NASA Astrophysics Data System (ADS)

    Hale, R. P.; Goodbred, S. L., Jr.; Bain, R. L.; Wilson, C.; Best, J.; Reed, M. J.

    2015-12-01

    The Ganges-Brahmaputra-Meghna River system (GBM) is among the world's largest in terms of both annual water and sediment discharge. The subaerial delta (110,000 km2) is home to ~160 million people, in addition to the ecologically and economically critical Sundarbans National Forest (SNF). Recent sediment budgets suggest that ~15% of the 1 x 109 t yr-1 sediment load carried by the GBM is subsequently advected along shore and inland via tidal activity, to the otherwise-abandoned SW portion of the delta. A unit-scale estimate based on observed offshore suspended sediment concentrations (SSC) >1.0 g L-1 suggests that sufficient sediment is available in the system to maintain the elevation of the subaerial delta plain, even under current relative sea-level-rise rates. Recent work measuring sedimentation within SNF corroborates this finding, and understanding these sediment delivery dynamics will be critical for protecting the future of nearby regions that are heavily populated, but drastically altered by human activities. Cross-channel hydrodynamic surveys were conducted to estimate what fraction of the water (and sediment) is diverted from the major tidal channels toward the SNF interior. Measurements including profiles of velocity and SSC were collected on spring and neap tides during the dry and monsoon seasons, along transects bracketing major conduit channels into the SNF. During the dry season, we observe water flux at the southern end of the study area to be in approximate equilibrium regardless of tidal range, with SSC <0.3 g L-1 during neap tides, and <1.0 g L-1 during spring tides. North of the SNF conduit channels, we observe equilibrium water discharge and similarly low SSC during neap tides, but a modest ebb dominance and surface SSC >1.0 g L-1 during spring tides. This suggests the possibility of additional inputs of water and sediment from an adjacent tidal channel, as well as a potential source for the deposition observed on the Sundarbans platform

  15. Preliminary Geologic Map of the Southern Funeral Mountains and Adjacent Ground-Water Discharge Sites, Inyo County, California, and Nye County, Nevada

    USGS Publications Warehouse

    Fridrich, Christopher J.; Thompson, Ren A.; Slate, Janet L.; Berry, M.E.; Machette, Michael N.

    2008-01-01

    This map covers the southern part of the Funeral Mountains, and adjacent parts of four structural basins - Furnace Creek, Amargosa Valley, Opera House, and central Death Valley. It extends over three full 7.5-minute quadrangles, and parts of eleven others - a total area of about 950 square kilometers. The boundaries of this map were drawn to include all of the known proximal hydrogeologic features that may affect the flow of ground water that discharges from the springs of the Furnace Creek wash area, in the west-central part of the map. These springs provide the major potable water supply for Death Valley National Park.

  16. Steel Creek fish, L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1991

    SciTech Connect

    Sayers, R.E. Jr.; Mealing, H.G. III

    1992-04-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal plain in west-central South Carolina. The Savannah River forms the western boundary of the site. Five major tributaries of the Savannah River -- Upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. All but Upper Three Runs Creek receive, or in the past received, thermal effluents from nuclear production reactors. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor, and protect the lower reaches from thermal impacts. The lake has an average width of approximately 600 m and extends along the Steel Creek valley approximately 7000 m from the dam to the headwaters. Water level is maintained at a normal pool elevation of 58 m above mean sea level by overflow into a vertical intake tower that has multilevel discharge gates. The intake tower is connected to a horizontal conduit that passes through the dam and releases water into Steel Creek. The Steel Creek Biological Monitoring Program was designed to meet environmental regulatory requirements associated with the restart of L-Reactor and complements the Biological Monitoring Program for L Lake. This extensive program was implemented to address portions of Section 316(a) of the Clean Water Act. The Department of Energy (DOE) must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems.

  17. Geologic strip map along the Hines Creek Fault showing evidence for Cenozoic displacement in the western Mount Hayes and northeastern Healy quadrangles, eastern Alaska Range, Alaska

    USGS Publications Warehouse

    Nokleberg, Warren J.; Aleinikoff, John N.; Bundtzen, Thomas K.; Hanshaw, Maiana N.

    2013-01-01

    Geologic mapping of the Hines Creek Fault and the adjacent Trident Glacier and McGinnis Glacier Faults to the north in the eastern Alaska Range, Alaska, reveals that these faults were active during the Cenozoic. Previously, the Hines Creek Fault, which is considered to be part of the strike-slip Denali Fault system (Ridgway and others, 2002; Nokleberg and Richter, 2007), was interpreted to have been welded shut during the intrusion of the Upper Cretaceous Buchanan Creek pluton (Wahrhaftig and others, 1975; Gilbert, 1977; Sherwood and Craddock, 1979; Csejtey and others, 1992). Our geologic mapping along the west- to west-northwest-striking Hines Creek Fault in the northeastern Healy quadrangle and central to northwestern Mount Hayes quadrangle reveals that (1) the Buchanan Creek pluton is truncated by the Hines Creek Fault and (2) a tectonic collage of fault-bounded slices of various granitic plutons, metagabbro, metabasalt, and sedimentary rock of the Pingston terrane occurs south of the Hines Creek Fault.

  18. 33 CFR 117.813 - Wappinger Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements New York § 117.813 Wappinger Creek. The draw of the Metro-North Commuter railroad bridge, mile 0.0 at New Hamburg, need not be opened for the passage...

  19. 33 CFR 117.929 - Durham Creek.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... OPERATION REGULATIONS Specific Requirements South Carolina § 117.929 Durham Creek. The removable span of the... Charleston of an emergency in the Bushy Park Reservoir, the span shall be removed as soon as possible...

  20. 33 CFR 117.557 - Curtis Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OPERATION REGULATIONS Specific Requirements Maryland § 117.557 Curtis Creek. The draw of the I695 bridge, mile 1.0 at Baltimore, shall open on signal if at least a one-hour notice is given to the...

  1. 33 CFR 117.571 - Spa Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OPERATION REGULATIONS Specific Requirements Maryland § 117.571 Spa Creek. The S181 bridge, mile 0.4, at Annapolis, Maryland: (a) From May 1 to October 31, Monday through Friday, except Federal and State...

  2. 33 CFR 117.557 - Curtis Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OPERATION REGULATIONS Specific Requirements Maryland § 117.557 Curtis Creek. The draw of the I695 bridge, mile 1.0 at Baltimore, shall open on signal if at least a one-hour notice is given to the...

  3. 33 CFR 117.571 - Spa Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OPERATION REGULATIONS Specific Requirements Maryland § 117.571 Spa Creek. The S181 bridge, mile 4.0, at Annapolis, Maryland: (a) From May 1 to October 31, Monday through Friday, except Federal and State...

  4. 33 CFR 117.571 - Spa Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OPERATION REGULATIONS Specific Requirements Maryland § 117.571 Spa Creek. The S181 bridge, mile 0.4, at Annapolis, Maryland: (a) From May 1 to October 31, Monday through Friday, except Federal and State...

  5. 33 CFR 117.557 - Curtis Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... OPERATION REGULATIONS Specific Requirements Maryland § 117.557 Curtis Creek. The draw of the I695 bridge, mile 1.0 at Baltimore, shall open on signal if at least a one-hour notice is given to the...

  6. 33 CFR 117.558 - Curtis Creek.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... OPERATION REGULATIONS Specific Requirements Maryland § 117.558 Curtis Creek. (a) The draw of the Pennington... Maryland Transportation Authority in Baltimore. Effective Date Note: By USCG-2010-1103, at 76 FR 9227,...

  7. 33 CFR 117.571 - Spa Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... OPERATION REGULATIONS Specific Requirements Maryland § 117.571 Spa Creek. The S181 bridge, mile 0.4, at Annapolis, Maryland: (a) From May 1 to October 31, Monday through Friday, except Federal and State...

  8. 33 CFR 117.557 - Curtis Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... OPERATION REGULATIONS Specific Requirements Maryland § 117.557 Curtis Creek. The draw of the I695 bridge, mile 1.0 at Baltimore, shall open on signal if at least a one-hour notice is given to the...

  9. 33 CFR 117.555 - College Creek.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.555 College Creek. The draws of the Naval Academy highway bridge, mile 0.3 at Annapolis, and the Maryland highway bridge, mile 0.4...

  10. 33 CFR 117.555 - College Creek.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.555 College Creek. The draws of the Naval Academy highway bridge, mile 0.3 at Annapolis, and the Maryland highway bridge, mile 0.4...

  11. 33 CFR 117.555 - College Creek.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Maryland § 117.555 College Creek. The draws of the Naval Academy highway bridge, mile 0.3 at Annapolis, and the Maryland highway bridge, mile 0.4...

  12. Kozai Cycles and Tidal Friction

    SciTech Connect

    L, K; P.P., E

    2009-07-17

    Several studies in the last three years indicate that close binaries, i.e. those with periods of {approx}< 3 d, are very commonly found to have a third body in attendance. We argue that this proves that the third body is necessary in order to make the inner period so short, and further argue that the only reasonable explanation is that the third body causes shrinkage of the inner period, from perhaps a week or more to the current short period, by means of the combination of Kozai cycles and tidal friction (KCTF). In addition, once KCTF has produced a rather close binary, magnetic braking also combined with tidal friction (MBTF) can decrease the inner orbit further, to the formation of a contact binary or even a merged single star. Some of the products of KCTF that have been suggested, either by others or by us, are W UMa binaries, Blue Stragglers, X-ray active BY Dra stars, and short-period Algols. We also argue that some components of wide binaries are actually merged remnants of former close inner pairs. This may include such objects as rapidly rotating dwarfs (AB Dor, BO Mic) and some (but not all) Be stars.

  13. Changes in the composition of ichthyoplankton assemblage and plastic debris in mangrove creeks relative to moon phases.

    PubMed

    Lima, A R A; Barletta, M; Costa, M F; Ramos, J A A; Dantas, D V; Melo, P A M C; Justino, A K S; Ferreira, G V B

    2016-07-01

    Lunar influence on the distribution of fish larvae, zooplankton and plastic debris in mangrove creeks of the Goiana Estuary, Brazil, was studied over a lunar cycle. Cetengraulis edentulus, Anchovia clupeoides and Rhinosardinia bahiensis were the most abundant fish larvae (56·6%), independent of the moon phase. The full moon had a positive influence on the abundance of Gobionellus oceanicus, Cynoscion acoupa and Atherinella brasiliensis, and the new moon on Ulaema lefroyi. The full and new moons also influenced the number of zoeae and megalopae of Ucides cordatus, protozoeae and larvae of caridean shrimps, and the number of hard and soft plastic debris, both <5 and >5 mm. Micro and macroplastics were present in samples from all 12 creeks studied, at densities similar to the third most abundant taxon, R. bahiensis. Cetengraulis edentulus and R. bahiensis showed a strong positive correlation with the last quarter moon, when there was less zooplankton available in the creeks and higher abundance of microplastic threads. Anchovia clupeoides, Diapterus rhombeus, U. lefroyi and hard microplastics were positively associated with different moon phases, when calanoid copepods, Caridean larvae and zoeae of U. cordatus were highly available in the creeks. Cynoscion acoupa, G. oceanicus and A. brasiliensis were strongly associated with the full moon, when protozoeae of caridean shrimps and megalopae of U. cordatus were also highly available, as were hard and soft macroplastics, paint chips (<5 mm) and soft microplastics. The results reinforce the role of mangrove creeks as nursery habitats. The moon phases influenced the distribution of fish larvae species, zooplankton and plastic debris by changing their compositions and abundances in the mangrove creeks of the Goiana Estuary when under the influence of different tidal current regimes.

  14. Assessment of volatile organic compounds in surface water at West Branch Canal Creek, Aberdeen Proving Ground, Maryland, 1999

    USGS Publications Warehouse

    Olsen, Lisa D.; Spencer, Tracey A.

    2000-01-01

    The U.S. Geological Survey (USGS) collected 13 surface-water samples and 3 replicates from 5 sites in the West Branch Canal Creek area at Aberdeen Proving Ground from February through August 1999, as a part of an investigation of ground-water contamination and natural attenuation processes. The samples were analyzed for volatile organic compounds, including trichloroethylene, 1,1,2,2-tetrachloroethane, carbon tetrachloride, and chloroform, which are the four major contaminants that were detected in ground water in the Canal Creek area in earlier USGS studies. Field blanks were collected during the sampling period to assess sample bias. Field replicates were used to assess sample variability, which was expressed as relative percent difference. The mean variability of the surface-water replicate analyses was larger (35.4 percent) than the mean variability of ground-water replicate analyses (14.6 percent) determined for West Branch Canal Creek from 1995 through 1996. The higher variability in surface-water analyses is probably due to heterogeneities in the composition of the surface water rather than differences in sampling or analytical procedures. The most frequently detected volatile organic compound was 1,1,2,2- tetrachloroethane, which was detected in every sample and in two of the replicates. The surface-water contamination is likely the result of cross-media transfer of contaminants from the ground water and sediments along the West Branch Canal Creek. The full extent of surface-water contamination in West Branch Canal Creek and the locations of probable contaminant sources cannot be determined from this limited set of data. Tidal mixing, creek flow patterns, and potential effects of a drought that occurred during the sampling period also complicate the evaluation of surface-water contamination.

  15. Superfund Record of Decision (EPA Region 8): Anaconda Smelter Site, Mill Creek, Montana (first remedial action), October 1988

    SciTech Connect

    Not Available

    1988-10-02

    The 160-acre community of Mill Creek is located in Deerlodge County, Montana, immediately adjacent to the Anaconda Smelter NPL site. The community of Mill Creek has been contaminated for over 100 years with smelter emissions, fugitive emissions of flu dust at the smelter, and continued fugitive emissions emanating from adjacent highly contaminated soils. Settled flue emissions in the community of Mill Creek, from the now-defunct copper-smelting operation, contain arsenic, cadmium, and lead. Environmental siting of the community and biological testing of pre-school children, led EPA to conclude that contamination in the Mill Creek area poses an imminent and substantial endangerment to the health of individuals residing there. The primary contaminant of concern at this site is arsenic. Cadmium and lead are secondary contaminants of concern. The selected remedial action for the site includes: permanent relocation of all residents (8 homes) with temporary erosional stabilization of disturbed areas by establishing and maintaining a vegetative cover; demolition, consolidation, and storage.

  16. A comparison of eelgrass, sea lettuce macroalgae, and marsh creeks as habitats for epibenthic fishes and decapods

    NASA Astrophysics Data System (ADS)

    Sogard, Susan M.; Able, Kenneth W.

    1991-11-01

    Densities of epibenthic fishes and decapod crustaceans (excluding xanthids and pagurids) were quantified with daytime throw trap sampling in shallow water habitats of New Jersey estuaries. We compared eelgrass ( Zostera marina), sea lettuce macroalgae ( Ulva lactuca), unvegetated sand/mud substrates adjacent to these vegetation types, and saltmarsh creeks. The highest total density of fishes occurred in marsh creeks, due primarily to high abundances of Menidia menidia. The highest total decapod density was also in a marsh creek, but only slightly surpassed the density in Zostera. Results of apriori comparisons tests for individual species demonstrated that vegetation (either Zostera or Ulva) was superior in quality (based on fish and decapod densities) to adjacent unvegetated substrates. Sites with Zostera as the dominant vegetation had higher densities of most fish species than sites with Ulva as the dominant vegetation, but only one decapod, Hippolyte pleuracanthus, was more abundant at eelgrass sites. Ulva lactuca, therefore, was an important habitat in areas lacking Zostera marina; for the decapods the two vegetation types were comparable in habitat quality, but for fishes Ulva did not provide an equivalent substitute for Zostera. Marsh creeks supported very high densities, but only for a few species that were also common in other habitats. Comparison of recruitment patterns suggested many species do not begin exploiting these estuarine habitats until relatively late in the summer, perhaps as result of peak spawning in mid-summer.

  17. Boundary Creek Thermal areas of Yellowstone National Park I: thermal activity and geologic setting

    SciTech Connect

    Hutchinson, R.A.

    1980-09-01

    Proposed geothermal leasing in the Island Park Geothermal Area (IPGA) in national forest and public lands adjacent to Yellowstone National Park has called attention to the moderate to high temperature springs of the Boundary Creek Thermal Areas. Up until late 1977 no description or geochemical inventory studies had been conducted in these areas. The thermal springs are scattered in four major groups along the Boundary Creek drainage with three to six km. of the IPGA - park border. Observations and analyses of physical and chemical indicators suggest that the source is under the Madison Plateau and that the waters are generally similar in the lower three thermal units. These hot springs should be monitored so as to provide early warning of change in the event that geothermal development in the IPGA causes withdrawal of groundwater from Yellow Stone National Park.

  18. Water quality monitoring report for the White Oak Creek Embayment. Environmental Restoration Program

    SciTech Connect

    Ford, C.J.; Wefer, M.T.

    1993-01-01

    Water quality monitoring activities that focused on the detection of resuspended sediments in the Clinch River were conducted in conjunction with the White Oak Creek Embayment (WOCE) time-critical Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) removal action to construct a sediment-retention structure at the mouth of White Oak Creek (WOC). Samples were collected by use of a 24-h composite sampler and through real-time water grab sampling of sediment plumes generated by the construction activities. Sampling stations were established both at the WOC mouth, immediately adjacent to the construction site, and at K-1513, the Oak Ridge K-25 Site drinking water intake approximately 9.6 km downstream in the Clinch River. Results are described.

  19. TIDALLY HEATED TERRESTRIAL EXOPLANETS: VISCOELASTIC RESPONSE MODELS

    SciTech Connect

    Henning, Wade G.; O'Connell, Richard J.; Sasselov, Dimitar D.

    2009-12-20

    Tidal friction in exoplanet systems, driven by orbits that allow for durable nonzero eccentricities at short heliocentric periods, can generate internal heating far in excess of the conditions observed in our own solar system. Secular perturbations or a notional 2:1 resonance between a hot Earth and hot Jupiter can be used as a baseline to consider the thermal evolution of convecting bodies subject to strong viscoelastic tidal heating. We compare results first from simple models using a fixed Quality factor and Love number, and then for three different viscoelastic rheologies: the Maxwell body, the Standard Anelastic Solid (SAS), and the Burgers body. The SAS and Burgers models are shown to alter the potential for extreme tidal heating by introducing the possibility of new equilibria and multiple response peaks. We find that tidal heating tends to exceed radionuclide heating at periods below 10-30 days, and exceed insolation only below 1-2 days. Extreme cases produce enough tidal heat to initiate global-scale partial melting, and an analysis of tidal limiting mechanisms such as advective cooling for earthlike planets is discussed. To explore long-term behaviors, we map equilibria points between convective heat loss and tidal heat input as functions of eccentricity. For the periods and magnitudes discussed, we show that tidal heating, if significant, is generally detrimental to the width of habitable zones.

  20. Tidal deformations of a spinning compact object

    NASA Astrophysics Data System (ADS)

    Pani, Paolo; Gualtieri, Leonardo; Maselli, Andrea; Ferrari, Valeria

    2015-07-01

    The deformability of a compact object induced by a perturbing tidal field is encoded in the tidal Love numbers, which depend sensibly on the object's internal structure. These numbers are known only for static, spherically-symmetric objects. As a first step to compute the tidal Love numbers of a spinning compact star, here we extend powerful perturbative techniques to compute the exterior geometry of a spinning object distorted by an axisymmetric tidal field to second order in the angular momentum. The spin of the object introduces couplings between electric and magnetic deformations and new classes of induced Love numbers emerge. For example, a spinning object immersed in a quadrupolar, electric tidal field can acquire some induced mass, spin, quadrupole, octupole and hexadecapole moments to second order in the spin. The deformations are encoded in a set of inhomogeneous differential equations which, remarkably, can be solved analytically in vacuum. We discuss certain subtleties in defining the tidal Love numbers in general relativity, which are due to the difficulty in separating the tidal field from the linear response of the object in the solution, even in the static case. By extending the standard procedure to identify the linear response in the static case, we prove analytically that the Love numbers of a Kerr black hole remain zero to second order in the spin. As a by-product, we provide the explicit form for a slowly-rotating, tidally-deformed Kerr black hole to quadratic order in the spin, and discuss its geodesic and geometrical properties.

  1. The hydrodynamics of surface tidal flow exchange in saltmarshes

    NASA Astrophysics Data System (ADS)

    Young, David L.; Bruder, Brittany L.; Haas, Kevin A.; Webster, Donald R.

    2016-04-01

    Modeling studies of estuary circulation show great sensitivity to the water exchange into and out of adjacent marshes, yet there is significant uncertainty in resolving the processes governing marsh surface flow. The objective of this study is to measure the estuary channel-to-saltmarsh pressure gradient and to guide parameterization for how it affects the surface flow in the high marsh. Current meters and high-resolution pressure transducers were deployed along a transect perpendicular to the nearby Little Ogeechee River in a saltmarsh adjacent to Rose Dhu Island near Savannah, Georgia, USA. The vertical elevations of the transducers were surveyed with static GPS to yield high accuracy water surface elevation data. It is found that water level differences between the Little Ogeechee River and neighboring saltmarsh are up to 15 cm and pressure gradients are up to 0.0017 m of water surface elevation change per m of linear distance during rising and falling tides. The resulting Little-Ogeechee-River-to-saltmarsh pressure gradient substantially affects tidal velocities at all current meter locations. At the velocity measurement station located closest to the Little Ogeechee River bank, the tidal velocity is nearly perpendicular to the bank. At this location, surface flow is effectively modeled as a balance between the pressure gradient force and the drag force due to marsh vegetation and bottom stress using the Darcy-Weisbach/Lindner's equations developed for flow-through-vegetation analysis in open channel flow. The study thus provides a direct connection between the pressure gradient and surface flow velocity in the high marsh, thereby overcoming a long-standing barrier in directly relating flow-through-saltmarsh studies to flow-through-vegetation studies in the open channel flow literature.

  2. Relativistic theory of tidal Love numbers

    SciTech Connect

    Binnington, Taylor; Poisson, Eric

    2009-10-15

    In Newtonian gravitational theory, a tidal Love number relates the mass multipole moment created by tidal forces on a spherical body to the applied tidal field. The Love number is dimensionless, and it encodes information about the body's internal structure. We present a relativistic theory of Love numbers, which applies to compact bodies with strong internal gravities; the theory extends and completes a recent work by Flanagan and Hinderer, which revealed that the tidal Love number of a neutron star can be measured by Earth-based gravitational-wave detectors. We consider a spherical body deformed by an external tidal field, and provide precise and meaningful definitions for electric-type and magnetic-type Love numbers; and these are computed for polytropic equations of state. The theory applies to black holes as well, and we find that the relativistic Love numbers of a nonrotating black hole are all zero.

  3. Assessment of water resources in lead-zinc mined areas in Cherokee County, Kansas, and adjacent areas

    USGS Publications Warehouse

    Spruill, T.B.

    1984-01-01

    A study was conducted to evaluate water-resource problems related to abandoned lead and zinc mines in Cherokee County, and adjacent areas in Oklahoma and Missouri. Discontinuities and perforations, which were produced by mining in the confining shale west of the Pennsylvanian-Mississippian geologic contact, have created artificial groundwater recharge and discharge areas. Abandoned wells and drill holes present the greatest contamination hazard to water supplies in the deep aquifer. There is a potential for downward movement from the shallow to the deep aquifer throughout the study area, with greatest potential in Ottawa County, Oklahoma. Principal effects of abandoned mines on groundwater quality are lowered pH and increased concentrations of sulfate and trace metals of water in the mines. No conclusive evidence of lateral migration of contaminated mine water from the mines into the water-supply wells adjacent to the mines was found. Analyses of water from the deep aquifer did not indicate trace-metal contamination. The effects of abandoned mines on streamwater quality are most severe in Short Creek and Tar Creek. Increased concentrations of zinc and manganese were observed in the Spring River below Short Creek Kansas. (USGS)

  4. Hydrological exchanges and Organic Matter dynamics in highly vulnerable tidal wetland ecosystems at the land-ocean interface

    NASA Astrophysics Data System (ADS)

    Tzortziou, M.; Neale, P.; Megonigal, P.; Loughner, C.

    2014-12-01

    Occupying a critical interface between the land and the sea, tidal wetlands are amongst the most ecologically valuable and economically important ecosystems on Earth, but also especially vulnerable to human pressures and climate change. These rich in biodiversity and highly productive ecosystems are hot spots of biogeochemical transformations, consistently exchanging Organic Matter with adjacent estuarine waters through tidal flushing. Here we discuss new results on the amount and directions of biogeochemical exchanges at the tidal wetland-estuary interface. Detailed microbial and photochemical degradation experiments and high resolution bio-optical observations in tidal freshwater and salt marsh systems of the Eastern US coast provide insights on the quality and fate of the organic compounds exported from tidal marshes and their influence on near-shore biological processes, biogeochemical cycles and optical variability. Impacts of anthropogenic activities and resulting air-pollution are also discussed. High resolution model runs were performed using the Community Multi-scale Air Quality (CMAQ) model, to examine atmospheric composition along the shoreline where processes such as sea and bay breeze circulations often favor the accumulation and air-deposition of atmospheric pollutants, impacting biogeochemical processes in sensitive tidal wetland ecosystems.

  5. Salinity influences on aboveground and belowground net primary productivity in tidal wetlands

    USGS Publications Warehouse

    Pierfelice, Kathryn N.; Graeme Lockaby, B.; Krauss, Ken W.; Conner, William H.; Noe, Gregory; Ricker, Matthew C.

    2015-01-01

    Tidal freshwater wetlands are one of the most vulnerable ecosystems to climate change and rising sea levels. However salinification within these systems is poorly understood, therefore, productivity (litterfall, woody biomass, and fine roots) were investigated on three forested tidal wetlands [(1) freshwater, (2) moderately saline, and (3) heavily salt-impacted] and a marsh along the Waccamaw and Turkey Creek in South Carolina. Mean aboveground (litterfall and woody biomass) production on the freshwater, moderately saline, heavily salt-impacted, and marsh, respectively, was 1,061, 492, 79, and 0  g m−2 year−1 versus belowground (fine roots) 860, 490, 620, and 2,128  g m−2 year−1. Litterfall and woody biomass displayed an inverse relationship with salinity. Shifts in productivity across saline sites is of concern because sea level is predicted to continue rising. Results from the research reported in this paper provide baseline data upon which coupled hydrologic/wetland models can be created to quantify future changes in tidal forest functions.

  6. Spatial and temporal variability of carbon dioxide and methane fluxes over semi-diurnal and spring-neap-spring timescales in a mangrove creek

    NASA Astrophysics Data System (ADS)

    Call, M.; Maher, D. T.; Santos, I. R.; Ruiz-Halpern, S.; Mangion, P.; Sanders, C. J.; Erler, D. V.; Oakes, J. M.; Rosentreter, J.; Murray, R.; Eyre, B. D.

    2015-02-01

    Automated in situ instrumentation captured high-resolution surface water pCO2, CH4 and 222Rn data at the creek mouth, and ∼500 m upstream in a sub-tropical mangrove ecosystem (Southern Moreton Bay, Australia, S27.78°, E153.38°) over a spring-neap-spring tidal cycle (∼15 days) during November 2013. The partial pressure of CO2 (pCO2) ranged from 385 to 26,106 μatm, CH4 from 1.8 to 889 nM, and 222Rn from 280 to 108,172 dpm m-3. Average surface water pCO2, CH4 and 222Rn were 4-fold higher at the upstream station. Surface water fluxes of CO2 and CH4 ranged from 9.4 to 629.2 mmol CO2 m-2 d-1 and 13.1 to 632.9 μmol CH4 m-2 d-1 depending upon the gas transfer model used and station location. Creek pCO2, CH4 and 222Rn displayed changes over both semi-diurnal and spring-neap-spring tidal scales. Semi-diurnally, all gases had a significant inverse relationship with water depth. Over the spring-neap-spring cycle, all gases exhibited an inverse relationship with tidal amplitude, with higher values during neap tides than spring tides. Estimated fluxes, porewater observations, and the significant positive relationship between surface water pCO2 and CH4, and 222Rn suggests groundwater exchange (i.e., tidal pumping) drives pCO2 and CH4 within the mangrove creek. We hypothesize that a combination of hourly and weekly groundwater-surface water exchange processes drive surface water pCO2 and CH4 in mangrove creeks. Semi-diurnally, flushing of crab burrows leads to high pCO2 and CH4 concentrations at low tide. During the spring-neap-spring cycle, older groundwater enriched in CO2, CH4 and 222Rn seeps into the creek as tidal amplitude decreases, leading to higher concentrations at neap tides.

  7. Hoe Creek groundwater restoration, 1989

    SciTech Connect

    Renk, R.R.; Crader, S.E.; Lindblom, S.R.; Covell, J.R.

    1990-01-01

    During the summer of 1989, approximately 6.5 million gallons of contaminated groundwater were pumped from 23 wells at the Hoe Creek underground coal gasification site, near Gillette, Wyoming. The organic contaminants were removed using activated carbon before the water was sprayed on 15.4 acres at the sites. Approximately 2647 g (5.8 lb) of phenols and 10,714 g (23.6 lb) of benzene were removed from the site aquifers. Phenols, benzene, toluene, ethylbenzene, and naphthalene concentrations were measured in 43 wells. Benzene is the only contaminant at the site exceeds the federal standard for drinking water (5 {mu}g/L). Benzene leaches into the groundwater and is slow to biologically degrade; therefore, the benzene concentration has remained high in the groundwater at the site. The pumping operation affected groundwater elevations across the entire 80-acre site. The water levels rebounded quickly when the pumping operation was stopped on October 1, 1989. Removing contaminated groundwater by pumping is not an effective way to clean up the site because the continuous release of benzene from coal tars is slow. Benzene will continue to leach of the tars for a long time unless its source is removed or the leaching rate retarded through mitigation techniques. The application of the treated groundwater to the surface stimulated plant growth. No adverse effects were noted or recorded from some 60 soil samples taken from twenty locations in the spray field area. 20 refs., 52 figs., 8 tabs.

  8. Use of PIT tag and underwater video recording in assessing estuarine fish movement in a high intertidal mangrove and salt marsh creek

    NASA Astrophysics Data System (ADS)

    Meynecke, Jan-Olaf; Poole, Geoffrey C.; Werry, Jonathan; Lee, Shing Yip

    2008-08-01

    We assessed movement patterns in relation to habitat availability (reflected by the extent of tidal flooding) for several commercially and recreationally important species in and out of a small mangrove creek within the subtropical Burrum River estuary (25°10'S 152°37'E) in Queensland, Australia. Movement patterns of Acanthopagrus australis, Pomadasys kaakan, Lutjanus russelli and Mugil cephalus were examined between December 2006 and April 2007 using a stationary passive integrated transponder (PIT) system adapted for saline environments (30-38 ppt) and underwater digital video cameras (DVCs). This is the second known application of a stationary PIT tag system to studying fish movement in estuarine environments. The transponder system was set in place for 104 days and recorded >5000 detections. Overall 'recapture' rate of tagged fish by the transponder system was >40%. We used PIT tags implanted in a total of 75 fish from a tidal creek connected to the main channel of the estuary. We also developed a high-resolution digital elevation (2.5 m cell size) model of the estuary derived from airborne light detection and ranging (LIDAR) and aerial imagery to estimate inundation dynamics within the tidal creek, and related the timing of inundation in various habitats to the timing of fish immigration to and emigration from the creek. Over 50% of all tagged fish were moving in and out of the creek at a threshold level when 50% of the mangrove forest became flooded. Individuals of all four species moved into and out of the tidal creek repeatedly at different times depending on species and size, indicating strong residential behaviour within the estuary. The main activity of fishes was at night time. Manual interpretation of video from >700 fish sightings at three different mangrove sites confirmed the findings of the stationary PIT system, that the function of shelter vs food in mangrove habitat may be size dependent. Our established techniques assess the spatial ecology

  9. Creek Women and the "Civilizing" of Creek Society, 1790-1820.

    ERIC Educational Resources Information Center

    Dysart, Jane E.

    Women in traditional Creek society, while making few decisions in the public domain, held almost absolute power in the domestic realm. When a Creek couple married, the husband moved into his wife's house and lived among her clan, her matrilineal kin. The house, household goods, fields, and children belonged to her. Boys were educated by their…

  10. 4. O'BRIAN CANAL/SECOND CREEK INTERSECTION Second Creek is in the ...

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

    4. O'BRIAN CANAL/SECOND CREEK INTERSECTION Second Creek is in the foreground; the O'Brian Canal is in the background; vicinity of East 112th Avenue and Potomac Road in Adams County - O'Brian Canal, South Platte River Drainage Area Northest of Denver, Brighton, Adams County, CO

  11. Debris flows on Belding Creek, Salmonberry River basin, northern Oregon Coast Range

    SciTech Connect

    Burris, L.M. . Dept. of Geology)

    1993-04-01

    Belding Creek, a tributary of the Salmonberry River, has experienced repeated debris flow episodes. The Salmonberry River flows through Paleocene Tillamook Basalt and is located at longitude 45[degree]43 minutes in the Northern Oregon Coast Range. On January 9, 1990, a debris flow initiated on a first order tributary of Belding Creek during a heavy precipitation event. A month later another debris flow initiated on a different first order stream under similar conditions. Both debris flows traveled for a distance of approximately 2.1 km and poured into the main Belding Creek channel washing out Belding Road which crosses the stream. Numerical data was obtained from the youngest flow deposit. The debris flow material density is 2.5 g/cm[sup 3]. It traveled at an average velocity of 2.9 m/s with a shear strength of 2.5 [times] 10[sup 4] dn/cm[sup 2], a friction angle of 4[degree], and a cohesion value of 1.4 [times] 10[sup 4] dn/cm[sup 3]. Less than 3% of the fine sediments deposited are clay and silt. Deposits from previous, older debris flow events are in and adjacent to the Belding Creek stream channel. Similar processes are evident in other major tributaries of the Salmonberry River, although these other stream channels have not shown recent activity. Each stream in the area that has experienced past debris flows similar to Belding Creek has a landslide feature at the top and follows regional lineation patterns.

  12. Tidal Streams Near and Far

    NASA Astrophysics Data System (ADS)

    Fardal, Mark A.

    2014-06-01

    The Pandas survey of stars in M31's disk and halo is crisscrossed by numerous tidal features from both M31 and the Milky Way. Here I focus on two narrow stellar streams visible in the survey. They have comparable angular extent in the survey (10-13 degrees long versus only 0.3 degree wide), but one is a local Milky Way stream at about 30 kpc and one is in M31, roughly 25 times more distant. I estimate the stellar mass and metallicity in the streams and the distance gradient along them. The kinematics of the M31 stream is sparsely sampled by red giant stars and globular clusters. Bayesian modeling of the stream data yields accurate constraints on the orbital parameters of the streams.

  13. Blasting of the Twin Creek`s highwall failure

    SciTech Connect

    Gray, C.J.; Bachmann, J.A.

    1996-12-01

    On December 26, 1994, at 1:00 a.m., the Twin Creeks Mine experienced a major highwall failure involving over 2.5 million tons. The long chain of events that led up to this failure actually started in late August when a truck driver first noticed the cracks in the highwall. Soon after, an intense survey prism monitoring program was initiated. An electronic, continuous monitor linked to Dispatch was soon in place which monitored the crack that was most likely to fail into the active pit area first. It wasn`t until early December when the graphs started showing greater increases in movement. On December 22, the acceleration curves skied-out. The 600 ft. highwall finally collapsed about three days later and left material spread 800 ft. across the bottom of the pit. Not knowing if the large overhangs above the slide would soon give away sending more material into the pit or if the numerous tension cracks on the surface would result in yet another major failure, it was only after restoring the rigid monitoring program and observing no movement that the company decided to drill and blast the overhanging material. The purpose of the blast wasn`t to cast the material into the pit, but to kick-out the toe so that the weight of material above would fall upon itself. After two months of preparation and almost three weeks of drilling and loading, the shot occurred on March 21, 1995. Approximately one million tons were successfully blasted that day, and presently they have completed mining the slough material itself and reestablished benches from the top.

  14. Baseline Characteristics of Jordan Creek, Juneau, Alaska

    USGS Publications Warehouse

    Host, Randy H.; Neal, Edward G.

    2004-01-01

    Anadromous fish populations historically have found healthy habitat in Jordan Creek, Juneau, Alaska. Concern regarding potential degradation to the habitat by urban development within the Mendenhall Valley led to a cooperative study among the City and Borough of Juneau, Alaska Department of Environmental Conservation, and the U.S. Geological Survey, that assessed current hydrologic, water-quality, and physical-habitat conditions of the stream corridor. Periods of no streamflow were not uncommon at the Jordan Creek below Egan Drive near Auke Bay stream gaging station. Additional flow measurements indicate that periods of no flow are more frequent downstream of the gaging station. Although periods of no flow typically were in March and April, streamflow measurements collected prior to 1999 indicate similar periods in January, suggesting that no flow conditions may occur at any time during the winter months. This dewatering in the lower reaches likely limits fish rearing and spawning habitat as well as limiting the migration of juvenile salmon out to the ocean during some years. Dissolved-oxygen concentrations may not be suitable for fish survival during some winter periods in the Jordan Creek watershed. Dissolved-oxygen concentrations were measured as low as 2.8 mg/L at the gaging station and were measured as low as 0.85 mg/L in a tributary to Jordan Creek. Intermittent measurements of pH and dissolved-oxygen concentrations in the mid-reaches of Jordan Creek were all within acceptable limits for fish survival, however, few measurements of these parameters were made during winter-low-flow conditions. One set of water quality samples was collected at six different sites in the Jordan Creek watershed and analyzed for major ions and dissolved nutrients. Major-ion chemistry showed Jordan Creek is calcium bicarbonate type water with little variation between sampling sites.

  15. Atmospheric noise of a breaking tidal bore.

    PubMed

    Chanson, Hubert

    2016-01-01

    A tidal bore is a surge of waters propagating upstream in an estuary as the tidal flow turns to rising and the flood tide propagates into a funnel-shaped system. Large tidal bores have a marked breaking roller. The sounds generated by breaking tidal bores were herein investigated in the field (Qiantang River) and in laboratory. The sound pressure record showed two dominant periods, with some similarity with an earlier study [Chanson (2009). J. Acoust. Soc. Am. 125(6), 3561-3568]. The two distinct phases were the incoming tidal bore when the sound amplitude increased with the approaching bore, and the passage of the tidal bore in front of the microphone when loud and powerful noises were heard. The dominant frequency ranged from 57 to 131 Hz in the Qiantang River bore. A comparison between laboratory and prototype tidal bores illustrated both common features and differences. The low pitch sound of the breaking bore had a dominant frequency close to the collective oscillations of bubble clouds, which could be modeled with a bubble cloud model using a transverse dimension of the bore roller. The findings suggest that this model might be over simplistic in the case of a powerful breaking bore, like that of the Qiantang River.

  16. Factors Controlling Tidal Flat Morphology in South San Francisco Bay

    NASA Astrophysics Data System (ADS)

    Bearman, J. A.; Foxgrover, A.; Friedrichs, C.; Jaffe, B.

    2006-12-01

    Since the 1850's, the San Francisco Bay has been subjected to a wide array of human-induced change. From the time of the first US Coast and Geodetic Survey bathymetric surveys in 1858, the saltmarshes and mudflats of South San Francisco Bay (SSFB) have decreased in area by 80% and 40%, respectively. Much of the saltmarsh loss was due to salt pond leveeing, while mudflat loss can be related to lack of sediment input, wind-wave erosion, and sea level rise. Plans for marsh restoration include breaching of salt pond levees with the goal of restoring the 15,100 acres of acquired ponds to tidal marsh the largest such restoration in the western US. The effect this would have upon the adjacent mudflats is unclear. In this analysis, the tidal flats of SSFB are broken into geographically similar regions and multiple cross-sections are drawn from mean high water to below mean lower low water at close intervals, allowing for a mean tidal flat bathymetric profile to be determined for each segment and for each time period 1858, 1898, 1931, 1956, 1983, 2005. Eigenfunction analysis is used to separate the spatial and temporal changes in profile shape into the dominant components of variability, allowing evaluation of the behavior of mudflats relative to spatially and temporally-varying forcings. The components of bathymetric variability derived from objective statistical analysis are compared to theoretical models for tidal flat profiles as a function of waves, tides and sediment supply. Theoretical models predict that wave-dominated or sediment-starved flats tend to have concave-upwards bathymetric profiles, whereas tide-dominated or accretionary flats tend to have convex-upwards bathymetric profiles. Initial results from an analysis of the 1980's bathymetry data suggest the South Bay mudflats can be broken into three morphologically distinct sections: 1) concave-up, erosional mudflats in the Eastern zone, which is most subject to wind waves; 2) convex-up, accretionary flats in

  17. Tidal river dynamics: Implications for deltas

    NASA Astrophysics Data System (ADS)

    Hoitink, A. J. F.; Jay, D. A.

    2016-03-01

    Tidal rivers are a vital and little studied nexus between physical oceanography and hydrology. It is only in the last few decades that substantial research efforts have been focused on the interactions of river discharge with tidal waves and storm surges into regions beyond the limit of salinity intrusion, a realm that can extend inland hundreds of kilometers. One key phenomenon resulting from this interaction is the emergence of large fortnightly tides, which are forced long waves with amplitudes that may increase beyond the point where astronomical tides have become extinct. These can be larger than the linear tide itself at more landward locations, and they greatly influence tidal river water levels and wetland inundation. Exploration of the spectral redistribution and attenuation of tidal energy in rivers has led to new appreciation of a wide range of consequences for fluvial and coastal sedimentology, delta evolution, wetland conservation, and salinity intrusion under the influence of sea level rise and delta subsidence. Modern research aims at unifying traditional harmonic tidal analysis, nonparametric regression techniques, and the existing understanding of tidal hydrodynamics to better predict and model tidal river dynamics both in single-thread channels and in branching channel networks. In this context, this review summarizes results from field observations and modeling studies set in tidal river environments as diverse as the Amazon in Brazil, the Columbia, Fraser and Saint Lawrence in North America, the Yangtze and Pearl in China, and the Berau and Mahakam in Indonesia. A description of state-of-the-art methods for a comprehensive analysis of water levels, wave propagation, discharges, and inundation extent in tidal rivers is provided. Implications for lowland river deltas are also discussed in terms of sedimentary deposits, channel bifurcation, avulsion, and salinity intrusion, addressing contemporary research challenges.

  18. On the time-course of adjacent and non-adjacent transposed-letter priming

    PubMed Central

    Ktori, Maria; Kingma, Brechtsje; Hannagan, Thomas; Holcomb, Phillip J.; Grainger, Jonathan

    2014-01-01

    We compared effects of adjacent (e.g., atricle-ARTICLE) and non-adjacent (e.g., actirle-ARTICLE) transposed-letter (TL) primes in an ERP study using the sandwich priming technique. TL priming was measured relative to the standard double-substitution condition. We found significantly stronger priming effects for adjacent transpositions than non-adjacent transpositions (with 2 intervening letters) in behavioral responses (lexical decision latencies), and the adjacent priming effects emerged earlier in the ERP signal, at around 200 ms post-target onset. Non-adjacent priming effects emerged about 50 ms later and were short-lived, being significant only in the 250-300 ms time-window. Adjacent transpositions on the other hand continued to produce priming in the N400 time-window (300-500 ms post-target onset). This qualitatively different pattern of priming effects for adjacent and non-adjacent transpositions is discussed in the light of different accounts of letter transposition effects, and the utility of drawing a distinction between positional flexibility and positional noise. PMID:25364497

  19. Changes in surf zone morphodynamics driven by multi-decadal contraction of a large ebb-tidal delta

    NASA Astrophysics Data System (ADS)

    Hansen, J. E.; Barnard, P.; Elias, E.

    2012-12-01

    The impact of large-scale deflation (76 million m3 of sediment loss) and contraction (~1 km) of a 150 km2 ebb-tidal delta over a half-century on hydrodynamics and sediment transport at Ocean Beach in San Francisco, CA (USA), onshore of the delta, is examined using a coupled wave and circulation model. The model is forced with representative wave and tidal conditions using recent (2005) and historic (1956) ebb-tidal delta bathymetry data sets. Comparison of the simulations indicate that along north/south trending Ocean Beach the contraction and deflation of the ebb-tidal delta has resulted in significant differences in the flow and sediment dynamics. Between 1956 and 2005 the transverse bar (the shallow attachment point of the ebb-tidal delta to the shoreline) migrated north ~1 km toward the inlet while a persistent alongshore flow and transport divergence point migrated south by ~500 m (Figure 1). Alongshore migration of these features has resulted in an increasing portion of onshore migrating sediment from the ebb-tidal delta, inferred by the contraction, to be transported north along the beach in 2005 versus south in 1956. The northerly migrating sediment is then trapped by Pt. Lobos, a rocky headland at the northern extreme of the beach, consistent with the observed shoreline accretion in this area. Conversely, alongshore migration of the transverse bar and divergence point has decreased the sediment supply to southern Ocean Beach, consistent with the observed erosion of the shoreline in this area. The approach described here is broadly applicable for investigating the causes of long-term morphological changes along urbanized beaches adjacent to inlet mouths worldwide.Figure 1. Ebb-tidal delta bathymetry in 1956 (A) and 2005 (B), 2 m contour interval to 20 m. Schematized pattern of alongshore transport along Ocean Beach and transport of onshore migrating sediment from the ebb-tidal delta in 1956 (C) and 2005 (D).

  20. Melting of Io by tidal dissipation

    NASA Technical Reports Server (NTRS)

    Peale, S. J.; Cassen, P.; Reynolds, R. T.

    1979-01-01

    The resonant structure of Io leads to forced eccentricities that are considerably larger than the free values. Although still modest by all standards, these forced eccentricities coupled with the enormous tides induced by Jupiter lead to magnitudes of tidal dissipation that are large enough to completely dominate the thermal history of Io. In the present paper, the forced eccentricities are calculated and then substituted into an expression for the total tidal dissipation. The results point to the possibility that the dissipation of tidal energy in Io may have melted a major fraction of Io's mass.

  1. Evolution of satellite resonances by tidal dissipation.

    NASA Technical Reports Server (NTRS)

    Greenberg, R.

    1973-01-01

    Analysis of a realistic model shows how satellites' gravitational interaction can halt their differential tidal evolution when resonant commensurabilities of their orbital periods are reached. The success of this study lends support to the hypothesis that orbit-orbit resonances among satellites in the solar system, including the Titan-Hyperion case, did evolve as a result of tidal energy dissipation. Consideration of the time scale for this evolution process, possible now that the capture mechanism has been revealed, can offer more sophisticated constraints on the tidal dissipation function, Q, and on past orbital conditions.

  2. ON THE TIDAL DISSIPATION OF OBLIQUITY

    SciTech Connect

    Rogers, T. M.; Lin, D. N. C. E-mail: lin@ucolick.org

    2013-05-20

    We investigate tidal dissipation of obliquity in hot Jupiters. Assuming an initial random orientation of obliquity and parameters relevant to the observed population, the obliquity of hot Jupiters does not evolve to purely aligned systems. In fact, the obliquity evolves to either prograde, retrograde, or 90 Degree-Sign orbits where the torque due to tidal perturbations vanishes. This distribution is incompatible with observations which show that hot Jupiters around cool stars are generally aligned. This calls into question the viability of tidal dissipation as the mechanism for obliquity alignment of hot Jupiters around cool stars.

  3. Dynamical response to a stationary tidal field

    NASA Astrophysics Data System (ADS)

    Landry, Philippe; Poisson, Eric

    2015-12-01

    We demonstrate that a slowly rotating compact body subjected to a stationary tidal field undergoes a dynamical response, in which the fluid variables and the interior metric vary on the time scale of the rotation period. This dynamical response requires the tidal field to have a gravitomagnetic component generated by external mass currents; the response to a gravitoelectric tidal field is stationary. We confirm that in a calculation carried out to first order in the body's rotation, the exterior geometry bears no trace of this internal dynamics; it remains stationary in spite of the time-dependent interior.

  4. Method and apparatus for tidal generation of power

    SciTech Connect

    Jury, W.W.

    1984-01-10

    A system is disclosed for generating electric power in response to the rise and fall of tidal water. The system comprises a movable container which is mounted on a float to move up with the tide with reference to a coaxially enclosed fixed plunger, which comprises and forces a body of liquid in the movable container to overflow into a first trough adjacent its upper end. The movable container is rigidly coupled to a movable plunger which depends coaxially into a fixed container, the plunger moving down with the tide to compress a body of liquid in the fixed container, causing it to overflow into a second trough adjacent its upper end. The two troughs are interconnected vertically through a gravity flow system, including a turbine which is constantly operated by the liquid falling from one or the other of the troughs, as the tide rises and falls. One embodiment comprises two fixed containers with movable plungers and two movable containers with fixed plungers. In another embodiment, a fixed container coaxially encloses a fixed plunger, between which is coaxially disposed a third body which serves in the dual capacity of a movable plunger to the fixed container, and a movable container to the fixed plunger.

  5. Assessment of water quality, benthic invertebrates, and periphyton in the Threemile Creek basin, Mobile, Alabama, 1999-2003

    USGS Publications Warehouse

    McPherson, Ann K.; Gill, Amy C.; Moreland, Richard S.

    2005-01-01

    The U.S. Geological Survey conducted a 4-year investigation of water quality and aquatic-community structure in Threemile Creek, an urban stream that drains residential areas in Mobile, Alabama. Water-quality samples were collected between March 2000 and September 2003 at four sites on Threemile Creek, and between March 2000 and October 2001 at two tributary sites that drain heavily urbanized areas in the watershed. Stream samples were analyzed for major ions, nutrients, fecal-indicator bacteria, and selected organic wastewater compounds. Continuous measurements of dissolved-oxygen concentrations, water temperature, specific conductance, and turbidity were recorded at three sites on Threemile Creek during 1999?2003. Aquatic-community structure was evaluated by conducting one survey of the benthic invertebrate community and multiple surveys of the algal community (periphyton). Benthic invertebrate samples were collected in July 2000 at four sites on Threemile Creek; periphyton samples were collected at four sites on Threemile Creek and the two tributary sites during 2000 ?2003. The occurrence and distribution of chemical constituents in the water column provided an initial assessment of water quality in the streams; the structure of the benthic invertebrate and algal communities provided an indication of the cumulative effects of water quality on the aquatic biota. Information contained in this report can be used by planners and resource managers in the evaluation of proposed total maximum daily loads and other restoration efforts that may be implemented on Threemile Creek. The three most upstream sites on Threemile Creek had similar water chemistry, characterized by a strong calcium-bicarbonate component; the most downstream site on Threemile Creek was affected by tidal fluctuations and mixing from Mobile Bay and had a strong sodium-chloride component. The water chemistry at the tributary site on Center Street was characterized by a strong sodium-chloride component

  6. A Peek into 'Alamogordo Creek'

    NASA Technical Reports Server (NTRS)

    2006-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2Figure 3

    On its 825th Martian day (May 20, 2006), NASA's Mars Exploration Rover Opportunity stopped for the weekend to place its instrument arm onto the soil target pictured here, dubbed 'Alamogordo Creek.' Two views from the panoramic camera, acquired at about noon local solar time, are at the top. Below them is a close-up view from the microscopic imager.

    At upper left, a false-color view emphasizes differences among materials in rocks and soil. It combines images taken through the panoramic camera's 753-nanometer, 535-nanometer and 432-nanometer filters. At upper right is an approximately true-color rendering made with the panoramic camera's 600-nanometer, 535-nanometer and 480-nanometer filters. The microscopic-imager frame covers the area outlined by the white boxes in the panoramic-camera views, a rectangle 3 centimeters (1.2 inches) across.

    As Opportunity traverses to the south, it is analyzing soil and rocks along the way for differences from those seen earlier. At this site, the soil contains abundant small spherical fragments, thought to be hematite-rich concretions, plus finer-grained basaltic sand. Most of the spherical fragments seen in the microscopic image are smaller than those first seen at the rover's landing site in 'Eagle Crater,' some five kilometers (3.1 miles) to the north. However, a few larger spherical fragments and other rock fragments can also be seen in the panoramic-camera images.

  7. Suspended sediment dynamics during the inter-monsoon season in the subaqueous Mekong Delta and adjacent shelf, southern Vietnam

    NASA Astrophysics Data System (ADS)

    Unverricht, Daniel; Nguyen, Thanh Cong; Heinrich, Christoph; Szczuciński, Witold; Lahajnar, Niko; Stattegger, Karl

    2014-01-01

    tidal current velocities. High tidal current velocities of up to 0.6 m/s near the sea bottom generate increasing SSCs of more than 25 μl/l in the water column. Additionally a significant trend of decreasing SSC from the near-seabed to the upper part of the water column can be observed. In terms of sediment transport the ebb phase dominates the tidal cycle by its higher tidal current velocities but the flood phase has the longer duration. The switch of the tidal current direction from ebb to flood phase occurs rapidly against which the change from flood to ebb phase requires up to 3 h. This leads to an asymmetry of the tidal ellipses and may cause a net-sediment transport from the shelf into the subaqueous Mekong Delta.In the subaqueous Mekong Delta and adjacent shelf, seven transects show similar patterns of SSCs dependent to the tidal phase. A hypopycnal sediment plume from the subaqueous Mekong Delta into the shelf region was not observed. Our results imply that resuspension by tidal currents dominates the sediment transport in the subaqueous Mekong Delta and adjacent shelf regions during the inter-monsoon season.

  8. Environmental setting of Maple Creek watershed, Nebraska

    USGS Publications Warehouse

    Fredrick, Brian S.; Linard, Joshua I.; Carpenter, Jennifer L.

    2006-01-01

    The Maple Creek watershed covers a 955-square-kilometer area in eastern Nebraska, which is a region dominated by agricultural land use. The Maple Creek watershed is one of seven areas currently included in a nationwide study of the sources, transport, and fate of water and chemicals in agricultural watersheds. This study, known as the topical study of 'Agricultural Chemicals: Sources, Transport, and Fate' is part of the National Water-Quality Assessment Program being conducted by the U.S. Geological Survey. The Program is designed to describe water-quality conditions and trends based on representative surface- and ground-water resources across the Nation. The objective of the Agricultural Chemicals topical study is to investigate the sources, transport, and fate of selected agricultural chemicals in a variety of agriculturally diverse environmental settings. The Maple Creek watershed was selected for the Agricultural Chemicals topical study because its watershed represents the agricultural setting that characterizes eastern Nebraska. This report describes the environmental setting of the Maple Creek watershed in the context of how agricultural practices, including agricultural chemical applications and irrigation methods, interface with natural settings and hydrologic processes. A description of the environmental setting of a subwatershed within the drainage area of Maple Creek is included to improve the understanding of the variability of hydrologic and chemical cycles at two different scales.

  9. Effect of tidal flat on the thermal effluent dispersion from a power plant

    NASA Astrophysics Data System (ADS)

    Yanagi, Tetsuo; Sugimatsu, Koichi; Shibaki, Hidenori; Shin, Hong-Ryeol; Kim, Hong-Sun

    2005-03-01

    The effect of a tidal flat on the dispersion of thermal effluent from the nuclear power plant at YongGwang (5.8 × 106 kW) along the west coast of Korea was investigated using intensive field observations and three-dimensional numerical simulations. The calculated sea surface temperature distribution reproduces well the observed one with a root mean square error of 0.53°C. A water column on the tidal flat area received a heat influx of 168 W m-2 on 17 April 2003 and transported the received heat to the adjacent coastal water at low water. The total heat supply from the tidal flat area to the coastal water was 6.6 × 1010 W, and was larger by about 1 order of magnitude than that from the power plant of 7.0 × 109 W on 17 April 2003, which was a fine day at spring tide. This fact shows that the effect of the tidal flat on the thermal effluent from the power plant is very large.

  10. Interactions between tidal turbine wakes: experimental study of a group of three-bladed rotors.

    PubMed

    Stallard, T; Collings, R; Feng, T; Whelan, J

    2013-02-28

    It is well known that a wake will develop downstream of a tidal stream turbine owing to extraction of axial momentum across the rotor plane. To select a suitable layout for an array of horizontal axis tidal stream turbines, it is important to understand the extent and structure of the wakes of each turbine. Studies of wind turbines and isolated tidal stream turbines have shown that the velocity reduction in the wake of a single device is a function of the rotor operating state (specifically thrust), and that the rate of recovery of wake velocity is dependent on mixing between the wake and the surrounding flow. For an unbounded flow, the velocity of the surrounding flow is similar to that of the incident flow. However, the velocity of the surrounding flow will be increased by the presence of bounding surfaces formed by the bed and free surface, and by the wake of adjacent devices. This paper presents the results of an experimental study investigating the influence of such bounding surfaces on the structure of the wake of tidal stream turbines. PMID:23319702

  11. Tidal-induced Groundwater Responses in L-shaped Coastal Aquifers considering Storm Surge and Rainfall Effect

    NASA Astrophysics Data System (ADS)

    Li, Wei-Ci; Chuang, Mo-Hsiung; Ni, Chuen-Fa

    2016-04-01

    Sea level fluctuations influenced by tidal variations are natural phenomenon in coastal areas aquifers and had been recognized the key mechanisms controlling groundwater flow fields in coastal aquifers. This study considered an L-shaped coastal aquifer system that includes Fengshan Creek in Hsinchu County, Taiwan, to quantify groundwater responses induced by sea level fluctuations. This study employed MODFLOW model to simulate tidal-induced head fluctuation dynamics, storm surge and rainfall effect in the coastal aquifer. The numerical results will compared with those obtained from analytical solutions and in situ data. The simulation domain and input parameters were obtained based on the field data from three boreholes, one tide stations, two river level gauges, three groundwater wells, and the DTM for the local area. This study focuses on the development of theoretical models of groundwater hydrology system located downstream rivers, estuaries, coastal regions, such as tidal environment to investigate the groundwater level fluctuation and flow in tidal area considering environmental planning issues. On the basis of the numerical model, the groundwater head fluctuations induced by the joint effect of storm surge, rainfall and oceanic tides is investigated and discussed in the coastal aquifer.

  12. Floodtide pulses after low tides in shallow subembayments adjacent to deep channels

    USGS Publications Warehouse

    Warner, J.C.; Schoellhamer, D.H.; Ruhl, C.A.; Burau, J.R.

    2004-01-01

    In shallow waters surface gravity waves (tides) propagate with a speed proportional to the square root of water depth (c = ???g(h+??)). As the ratio of free surface displacement to mean depth (??/h) approaches unity the wave will travel noticeably faster at high tide than at low tide, creating asymmetries in the tidal form. This physical process is explained analytically by the increased significance of friction and the nonlinear terms in the continuity and momentum equations. In a tidal system comprising a shallow bay adjacent to a deeper channel, tidal asymmetries will be more prevalent in the shallow bay. Thus strong barotropic gradients can be generated between the two, producing rapid accelerations of currents into the bay (relative to other bay tidal processes) and create a maximum peak in the flood tide that we describe as a floodtide pulse. These floodtide pulses can promote a landward flux of suspended-sediment into the bay. In Grizzly Bay (part of northern San Francisco Bay, USA), field observations verify the occurrence of floodtide pulses during the lowest low tides of the year. No pulses were observed in neighboring Honker Bay, which has an average depth ???30 cm greater than Grizzly Bay. Numerical simulations of northern San Francisco Bay using realistic bathymetry demonstrated that floodtide pulses occurred in Grizzly Bay but not in Honker Bay, consistent with the observations. Both observations and numerical simulations show that floodtide pulses promote a landward flux of sediment into Grizzly Bay. Numerical simulations of an idealized bay-channel system quantify the importance of mean depth and friction in creating these floodtide pulses. ?? 2004 Elsevier Ltd. All rights reserved.

  13. Evidence for the importance of ductile shear in regional fabric development in Grenville-age gneisses of the Beaver Creek region, Northwest Lowlands, New York State

    SciTech Connect

    Tewksbury, B.; Culbertson, H.; Marcoline, J.; Walvoord, M. . Dept. of Geology)

    1993-03-01

    In the Beaver Creek region of the Northwest Lowlands, Brown (1989) has described Grenville-age metasedimentary and metaigneous rocks as showing a prominent regional foliation, early southeastward emplacement of a nappe complex (the North Gouverneur Nappe), 2 subsequent generations of folds, and late regional faulting along the Beaver Creek, Pleasant Lake, and Hickory-Mud Lakes faults. The authors examined a variety of units across the Beaver Creek region, including a granitic augen gneiss immediately west of the Beaver Creek Fault Zone, an alaskitic gneiss immediately below Brown's (1989) North Gouverneur Nappe Sole Fault, a biotitic granitic gneiss within the body of Brown's North Gouverneur Nappe, and hornblende augen gneisses and metasediments adjacent to the granitic gneisses. Each of the granitic units has moderately well-developed to extremely well-developed quartz ribbon lineations, and all show at least 2 ductile shear fabrics. Shear fabrics are present as well in the hornblende augen gneisses but are essentially absent in most of the metasedimentary lithologies, even those immediately adjacent to well-lineated, sheared granitic gneiss. The earliest shear fabrics exhibit spectacular quartz ribbon lineations, sigma grains, and, in the hornblende augen gneiss, shear bands. Granitic gneisses in the Beaver Creek Region show shear fabrics in addition to the main fabric in the rock. A second, variably-recovered shear fabric with quartz ribbons and well-developed sigma grains with core and mantle structure overprints the main shear fabric and shows largely the same sense of shear. The authors suggest further that a regional kinematic model for the Beaver Creek region must take into account significant, protracted regional shear, perhaps including formation of sheath folds, as in the Hyde School Gneiss at Payne Lake and Dobbs Creek.

  14. Water-quality appraisal, Mammoth Creek and Hot Creek, Mono County, California

    USGS Publications Warehouse

    Setmire, J.G.

    1984-01-01

    A late summer reconnaissance in 1981 and a spring high-flow sampling in 1982 of Mammoth Creek and Hot Creek, located in the Mammoth crest area of the Sierra Nevada, indicated that mineralization, eutrophication, sedimentation, and limited areas of fecal contamination were occurring. Mineralization, indicated by a downstream increase in dissolved-solids concentration, was due primarily to geothermal springs that gradually decreased in the percentage of calcium, increased in the percentage of magnesium and sodium, and caused fluctuating, but overall increasing percentage of fluoride, sulfate, and chloride. Resulting water quality in Mammoth Creek was similar to that of the springs forming Hot Creek. Eutrophication was observed in Twin Lakes and the reach of Hot Creek below the fish hatchery. Twin Lakes had floating mats of algae and a high dissolved-oxygen saturation of 147 percent at a pH of 9.2. Hot Creek had excessive aquatic vascular plant and algae growth, dissolved-oxygen saturations ranging from 65 to 200 percent, algal growth potential of 30 milligrams per liter, and nitrates and phosphates of 0.44 and 0.157 milligrams per liter. Sedimentation was noted in observations of bed-material composition showing the presence of fine material beginning at Sherwin Creek Road. Fecal contamination was indicated by fecal coliform counts of 250 colonies per 100 milliliters and fecal streptococcal counts greater than 1,000 colonies per 100 milliliters. (USGS)

  15. Steel Creek water quality: L-Lake/Steel Creek Biological Monitoring Program, November 1985--December 1991

    SciTech Connect

    Bowers, J.A.; Kretchmer, D.W.; Chimney, M.J.

    1992-04-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal Plain in west-central South Carolina. The Savannah River forms the western boundary of the site. Five major tributaries of the Savannah River -- upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. All but Upper Three Runs Creek receive, or in the past received, thermal effluents from nuclear production reactors. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor, and protect the lower reaches from thermal impacts. The Steel Creek Biological Monitoring Program was designed to meet envirorunental regulatory requirements associated with the restart of L-Reactor and complements the Biological Monitoring Program for L Lake. This extensive program was implemented to address portions of Section 316(a) of the Clean Water Act. The Department of Energy (DOE) must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems.

  16. Steel Creek fish: L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1987

    SciTech Connect

    Paller, M.H.; Heuer, J.H.; Kissick, L.A.

    1988-03-01

    Fish samples were collected from Steel Creek during 1986 and 1987 following the impoundment of the headwaters of the stream to form L-Lake, a cooling reservoir for L-Reactor which began operating late in 1985. Electrofishing and ichthyoplankton sample stations were located throughout the creek. Fykenetting sample stations were located in the creek mouth and just above the Steel Creek swamp. Larval fish and fish eggs were collected with 0.5 m plankton nets. Multivariate analysis of the electrofishing data suggested that the fish assemblages in Steel Creek exhibited structural differences associated with proximity to L-Lake, and habitat gradients of current velocity, depth, and canopy cover. The Steel Creek corridor, a lotic reach beginning at the base of the L-Lake embankment was dominated by stream species and bluegill. The delta/swamp, formed where Steel Creek enters the Savannah River floodplain, was dominated by fishes characteristic of slow flowing waters and heavily vegetated habitats. The large channel draining the swamp supported many of the species found in the swamp plus riverine and anadromous forms.

  17. Big Creek Hydroelectric System, East & West Transmission Line, 241mile ...

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

    Big Creek Hydroelectric System, East & West Transmission Line, 241-mile transmission corridor extending between the Big Creek Hydroelectric System in the Sierra National Forest in Fresno County and the Eagle Rock Substation in Los Angeles, California, Visalia, Tulare County, CA

  18. Barrel view from southwest. Waterville Bridge, Spanning Swatara Creek ...

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

    Barrel view from southwest. - Waterville Bridge, Spanning Swatara Creek at Appalachian Trail (moved from Little Pine Creek at State Route 44, Waterville, Lycoming County), Green Point, Lebanon County, PA

  19. Lower connections from south. Waterville Bridge, Spanning Swatara Creek ...

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

    Lower connections from south. - Waterville Bridge, Spanning Swatara Creek at Appalachian Trail (moved from Little Pine Creek at State Route 44, Waterville, Lycoming County), Green Point, Lebanon County, PA

  20. Rock Creek and Potomac Parkway / Waterside Drive Sycamore and ...

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

    Rock Creek and Potomac Parkway / Waterside Drive Sycamore and White Ash Trees, Rock Creek and Potomac Parkway, median between northbound and southbound lanes near the Waterside Drive exit and entrance ramps., Washington, District of Columbia, DC

  1. 1. WATER ENTERING CONFLUENCE POOL FROM BEAR CREEK AT LEFT, ...

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

    1. WATER ENTERING CONFLUENCE POOL FROM BEAR CREEK AT LEFT, AND FROM SANTA ANA RIVER THROUGH TUNNEL #0 AT RIGHT. VIEW TO NORTHEAST. - Santa Ana River Hydroelectric System, Bear Creek Diversion Dam & Confluence Pool, Redlands, San Bernardino County, CA

  2. 40. UNDERSIDE OF TOWN CREEK SPAN (LEFT) AND PEARMAN BRIDE ...

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

    40. UNDERSIDE OF TOWN CREEK SPAN (LEFT) AND PEARMAN BRIDE (RIGHT) FROM BENEATH BRIDGES, FACING EAST TOWARDS COOPER RIVER SPAN - Grace Memorial Bridge, U.S. Highway 17 spanning Cooper River & Town Creek , Charleston, Charleston County, SC

  3. Detail view of Fanno Creek trestle, showing trestle substructure, view ...

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

    Detail view of Fanno Creek trestle, showing trestle substructure, view looking north - Oregon Electric Railroad, Fanno Creek Trestle, Garden Home to Wilsonville Segment, Milepost 34.7, Garden Home, Washington County, OR

  4. 13. Detail view of Sterling Creek lettuce shed showing second ...

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

    13. Detail view of Sterling Creek lettuce shed showing second floor window sill - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  5. 12. Detail view of Sterling Creek lettuce shed showing floor ...

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

    12. Detail view of Sterling Creek lettuce shed showing floor joist and support beams - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  6. 1. View of Sterling Creek lettuce shed looking south, with ...

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

    1. View of Sterling Creek lettuce shed looking south, with road in foreground - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  7. 15. Detail view of Sterling Creek lettuce shed showing second ...

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

    15. Detail view of Sterling Creek lettuce shed showing second floor support beams. - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  8. 5. View of Sterling Creek lettuce shed looking northwest showing ...

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

    5. View of Sterling Creek lettuce shed looking northwest showing office - Richmond Hill Plantation, Sterling Creek Lettuce Shed, East of Richmond Hill on Ford Neck Road, Richmond Hill, Bryan County, GA

  9. Half Moon Cove Tidal Project. Feasibility report

    NASA Astrophysics Data System (ADS)

    1980-11-01

    The project would be located in a small cove in the northern part of Cobscook Bay in the vicinity of Eastport, Maine. The basin impounded by the barrier when full will approximate 1.2 square miles. The average tidal range at Eastport is 18.2 feet. The maximum spring tidal range will be 26.2 feet and the neap tidal range 12.8 feet. The project will be of the single pool-type single effect in which generation takes place on the ebb tide only. Utilizing an average mean tidal range of 18.2 feet the mode of operation enables generation for approximately ten and one-half (10-1/2) hours per day or slightly in excess of five (5) hours per tide. The installed capacity will be 12 MW utilizing 2 to 6 MW units. An axial flow, or Bulb type of turbine was selected for this study.

  10. Lunar Tidal Deformation and the Deep Interior

    NASA Astrophysics Data System (ADS)

    Williams, James G.; Konopliv, Alex S.; Park, Ryan; Boggs, Dale H.; Asmar, Sami W.; Yuan, Dah-Ning; Ratcliff, James; Watkins, Michael M.; Smith, David E.; Zuber, Maria

    2016-10-01

    The gravitational attractions of the Earth and Sun raise tides on the Moon. The amplitudes of vertical tidal variations are typically 0.1 to 0.15 m in size. The GRAIL mission determines the potential Love number k2 = 0.02422 with <1% uncertainty. Models with a crust, mantle, deep dissipating region, and fluid core can match the k2. Lunar Laser Ranging determines tidal dissipation Q=38 at 1 month period and Q=41 at 1 yr. Dissipation in the deep mantle appears to cause the low tidal Q and Q versus tidal period is a clue about the dissipation mechanism. The dissipating region has an upper radius of at least 535 km. The vertical displacement Love number h2 is detected.

  11. Lithologic Coring in the Lower Anacostia Tidal Watershed, Washington, D.C., July 2002

    USGS Publications Warehouse

    Tenbus, Frederick J.

    2003-01-01

    Little is known about the volumetric flux of ground water to the lower tidal Anacostia River, or whether ground-water flow is an important component of the contaminant load in this part of the Anacostia River. The watershed is in the eastern part of Washington, D.C., and has been subjected to over 200 years of urbanization and modifications of the river channel and nearby land areas. These anthropogenic factors, along with tidal fluctuations in the river, make ground-water data collection and interpretations difficult. The U.S. Geological Survey is cooperating with the District of Columbia Department of Health, Environmental Health Administration, Bureau of Environmental Quality, Water Quality Division, in a study to assess nonpoint-source pollution from ground water into the lower tidal Anacostia River. Lithologic cores from drilling activities conducted during July 2002 in the study area have been interpreted in the context of geologic and hydrogeologic information from previous studies in the lower Anacostia tidal watershed. These interpretations can help achieve the overall project goals of characterizing ground-water flow and contaminant load in the study area. Hydrostratigraphic units encountered during drilling generally consisted of late Pleistocene to Holocene fluvial deposits overlying Cretaceous fluvial/deltaic deposits. Cores collected in Beaverdam Creek and the Anacostia River indicated high- and low-energy environments of deposition, respectively. Two cores collected near the river showed different types of anthropogenic fill underlain by low-energy deposits, which were in turn underlain by sand and gravel. A third core collected near the river consisted primarily of sand and gravel with no artificial fill.

  12. Characterization of Biogeochemical Variability in a Tidal Estuary Using High Resolution Optical Measurements

    NASA Astrophysics Data System (ADS)

    Chang, G.; Jones, C.; Martin, T.

    2015-12-01

    The Berry's Creek Study Area (BCSA) is a tidal estuary located in New Jersey. Several chemicals of potential concern (COPCs) are present in the BCSA waterway and marshes, including mercury, methyl mercury, and polychlorinated biphenyls. Concentrations of COPCs and suspended solids in the BCSA vary temporally and spatially due to tidal variability, freshwater flow events, and interaction of marsh, waterway, and sediment bed materials. This system-wide variability confounds evaluation of COPC sources and transport mechanisms when using conventional laboratory-based analysis of discrete water column samples. Therefore, an optically-based biogeochemical monitoring program was conducted using near-continuous measurements of optical properties and an optical-biogeochemical partial least-squares regression model pioneered by B. Bergamaschi (USGS) and colleagues. The objective of the study was to characterize COPC concentration dynamics in the BCSA water column and relate the analysis to sediment bed processes. Optical-biogeochemical model results indicated that, in general, measured optical properties were sufficient for predicting COPC concentrations to within 10% of the accuracy of laboratory-based analytical measurements. The continuous, high temporal resolution time series of COPC concentrations determined by the optical-biogeochemical model enabled evaluation of the sediment bed dynamics and variability of COPCs in the surface water of the BCSA. Results indicate that tidally-induced resuspension of waterway sediment bed particulates is the primary mechanism for transport of COPCs to surface water. Waterway-marsh tidal exchange shows a net mass flux of particulate COPCs from waterway to marsh, indicating that particulate COPCs are retained and accumulate in the marshes with relatively little net export of dissolved COPCs from the marshes to the waterway.

  13. Sediment accretion in tidal freshwater forests and oligohaline marshes of the Waccamaw and Savannah Rivers, USA

    USGS Publications Warehouse

    Ensign, Scott H.; Hupp, Cliff R.; Noe, Gregory B.; Krauss, Ken W.; Stagg, Camille L.

    2014-01-01

    Sediment accretion was measured at four sites in varying stages of forest-to-marsh succession along a fresh-to-oligohaline gradient on the Waccamaw River and its tributary Turkey Creek (Coastal Plain watersheds, South Carolina) and the Savannah River (Piedmont watershed, South Carolina and Georgia). Sites included tidal freshwater forests, moderately salt-impacted forests at the freshwater–oligohaline transition, highly salt-impacted forests, and oligohaline marshes. Sediment accretion was measured by use of feldspar marker pads for 2.5 year; accessory information on wetland inundation, canopy litterfall, herbaceous production, and soil characteristics were also collected. Sediment accretion ranged from 4.5 mm year−1 at moderately salt-impacted forest on the Savannah River to 19.1 mm year−1 at its relict, highly salt-impacted forest downstream. Oligohaline marsh sediment accretion was 1.5–2.5 times greater than in tidal freshwater forests. Overall, there was no significant difference in accretion rate between rivers with contrasting sediment loads. Accretion was significantly higher in hollows than on hummocks in tidal freshwater forests. Organic sediment accretion was similar to autochthonous litter production at all sites, but inorganic sediment constituted the majority of accretion at both marshes and the Savannah River highly salt-impacted forest. A strong correlation between inorganic sediment accumulation and autochthonous litter production indicated a positive feedback between herbaceous plant production and allochthonous sediment deposition. The similarity in rates of sediment accretion and sea level rise in tidal freshwater forests indicates that these habitats may become permanently inundated if the rate of sea level rise increases.

  14. The Boulder Creek Batholith, Front Range, Colorado

    USGS Publications Warehouse

    Gable, Dolores J.

    1980-01-01

    The Boulder Creek batholith is the best known of several large Precambrian batholiths of similar rock composition that crop out across central Colorado. The rocks in the batholith belong to the calc-alkaline series and range in composition from granodiorite through quartz diorite (tonalite) to gneissic aplite. Two rock types dominate': the Boulder Creek Granodiorite, the major rock unit, and a more leucocratic and slightly younger unit herein named Twin Spruce Quartz Monzonite. Besides mafic inclusions, which occur mainly in hornblende-bearing phases of the Boulder Creek Granodiorite, there are cogenetic older and younger lenses, dikes, and small plutons of hornblende diorite, hornblendite, gabbro, and pyroxenite. Pyroxenite is not found in the batholith. The Boulder Creek Granodiorite in the batholith represents essentially two contemporaneous magmas, a northern body occurring in the Gold Hill and Boulder quadrangles and a larger southern body exposed in the Blackhawk and the greater parts of the Tungsten and Eldorado Springs quadrangles. The two bodies are chemically and mineralogically distinct. The northern body is richer in CaO and poorer in K2O, is more mafic, and has a larger percentage of plagioclase than the southern body. A crude sequence of rock types occurs from west to east in the batholith accompanied by a change in plagioclase composition from calcic plagioclase on the west to sodic on the east. Ore minerals tend to decrease, and the ratio potassium feldspar:plagioclase increases inward from the western contact of the batholith, indicating that the Boulder Creek batholith is similar to granodiorite batholiths the world over. Emplacement of the Boulder Creek batholith was contemporaneous with plastic deformation and high-grade regional metamorphism that folded the country rock and the batholith contact along west-northwest and north-northwest axes. Also, smaller satellitic granodiorite bodies tend to conform to the trends of foliation and fold axes in

  15. Morphodynamics of tidal networks: advances and challenges

    NASA Astrophysics Data System (ADS)

    Coco, G.; Olabarrieta, M.; van Maanen, B.; Zhou, Z.; Tinoco, R.

    2012-12-01

    Tidal embayments are complex environments at the boundary between land and sea. Their evolution, natural or human-induced, feeds back onto ecological, economic and societal functions. Overall, the ability to manage tidal embayments successfully and maintain their value hinges on our knowledge of the system. The morphological behaviour of tidal embayments, however, is very complex because of the variety of feedback mechanisms which lead to morphological change. In recent years, numerical studies have highlighted that the feedback between the hydrodynamics, sediment transport and morphological evolution can lead to the development of tidally-forced morphological networks characterized by slowly-evolving bifurcating channels. Both tidal range and the initial bathymetry appear to have a strong control on the morphological characteristics of the tidal network by affecting final basin hypsometry and channel patterns. Although promising, none of the numerical models presented in the literature and capable of simulating the growth of a tidal network have been scrutinized against field or laboratory data. Here, we show and discuss the performance of one of those numerical models against detailed laboratory data. Preliminary results indicate that numerical simulations can reproduce the general features of pattern development but that a better description of many fast- and small-scale processes is needed to achieve better model-data agreement. Unsurprisingly, the model shows a strong sensitivity to frictional effects and resuspension parameterizations. Numerical models of morphodynamics tend to neglect some physical or biological processes that affect the short- and long-term evolution of tidal networks. In terms of physical processes, wind waves, interacting with the ebb shoal and tidal currents at the mouth of the embayment can significantly affect hydro- and morphodynamics. Under high wave conditions waves can break in the inlet area producing wave induced circulation

  16. Hydrology and Flood Profiles of Duck Creek and Jordan Creek Downstream from Egan Drive, Juneau, Alaska

    USGS Publications Warehouse

    Curran, Janet H.

    2007-01-01

    Hydrologic and hydraulic updates for Duck Creek and the lower part of Jordan Creek in Juneau, Alaska, included computation of new estimates of peak streamflow magnitudes and new water-surface profiles for the 10-, 50-, 100-, and 500-year floods. Computations for the 2-, 5-, 10-, 25-, 50-, 100-, 200-, and 500-year recurrence interval flood magnitudes for both streams used data from U.S. Geological Survey stream-gaging stations weighted with regional regression equations for southeast Alaska. The study area for the hydraulic model consisted of three channels: Duck Creek from Taku Boulevard near the stream's headwaters to Radcliffe Road near the end of the Juneau International Airport runway, an unnamed tributary to Duck Creek from Valley Boulevard to its confluence with Duck Creek, and Jordan Creek from a pedestrian bridge upstream from Egan Drive to Crest Street at Juneau International Airport. Field surveys throughout the study area provided channel geometry for 206 cross sections, and geometric and hydraulic characteristics for 29 culverts and 15 roadway, driveway, or pedestrian bridges. Hydraulic modeling consisted of application of the U.S. Army Corps of Engineers' Hydrologic Engineering Center River Analysis System (HEC-RAS) for steady-state flow at the selected recurrence intervals using an assumed high tide of 20 feet and roughness coefficients refined by calibration to measured water-surface elevations from a 2- to 5-year flood that occurred on November 21, 2005. Model simulation results identify inter-basin flow from Jordan Creek to the southeast at Egan Drive and from Duck Creek to Jordan Creek downstream from Egan Drive at selected recurrence intervals.

  17. Water-quality appraisal. Mammoth Creek and Hot Creek, Mono County, California

    SciTech Connect

    Setmire, J.G.

    1984-06-01

    A late summer reconnaissance in 1981 and a spring high-flow sampling in 1982 of Mammoth Creek and Hot Creek, located in the Mammoth crest area of the Sierra Nevada, indicated that three water-quality processes were occurring: (1) mineralization; (2) eutrophication; and (3) sedimentation. Limited areas of fecal contamination were also observed. Mineralization due primarily to geothermal springs increased dissolved-solids concentration downstream, which changed the chemical composition of the water. The percentage of calcium decreased gradually, the percentage of magnesium and sodium increased, and the percentage of fluoride, sulfate, and chloride fluctuated, but increased overall. These changes produced water quality in Mammoth Creek similar to that of the springs forming Hot Creek. Twin Lakes and the reach of Hot Creek below the fish hatchery showed evidence of eutrophication. Twin Lakes had floating mats of algae and a high dissolved-oxygen saturation of 147% at a pH of 9.2. Hot Creek had abundant growth of aquatic vascular plants and algae, dissolved-oxygen saturations ranging from 65% to 200%, algal growth potential of 30 milligrams per liter, nitrate concentration of 0.44 milligram per liter, and phosphate concentration of 0.157 milligram per liter. Sediment deposition was determined from detailed observations of bed-material composition, which showed that fine material was deposited at Sherwin Creek Road and downstream. Fecal contamination was indicated by fecal-coliform bacteria counts of 250 colonies per 100 milliliters and fecal-streptococcal bacteria counts greater than 1000 colonies per 100 milliliters. Although bacterial sampling was sporadic and incomplete, it did indicate adverse effects on water quality for the following beneficial uses that have been identified for Mammoth Creek and Hot Creek: (1) municipal supply; (2) cold-water habitat; and (3) contact and noncontact water recreation. 6 refs., 15 figs., 15 tabs.

  18. Tidal Despinning Timescales in the Solar System

    NASA Astrophysics Data System (ADS)

    Chyba, C. F.; Thomas, P. J.

    1998-09-01

    Planets and satellites in the Solar System despin to a spin-evolved end-state due to tidal dissipation. The usual derivation for the despinning timescale sets the change in spin angular momentum equal to to the gravitational torque acting on the object's tidal bulge (MacDonald 1964, Goldreich and Soter 1966, Peale 1974, 1977). The despinning timescale is found to be proportional to the difference between the initial and final spin angular velocities, and is finite. However, this approximate derivation ignores the orbital mean motion n of the despinning object, and is less and less satisfactory as the object.s spin angular velocity w approaches n. We have instead calculated tidal despinning times by applying the formalism of Peale and Cassen (1978) to calculate tidal energy dissipation due to tides raised on a non-spin-locked object. Tidal heating in the latter case is larger than tidal heating in the spin locked case by a factor (1/7)[(w-n)/n](1/e(2) ), where e is the orbital eccentricity. This factor is initially greater than 10(4) for many objects in the Solar System. Calculating despinning times from energy loss, we find that the despinning timescale includes a previously neglected term that goes to infinity logarithmically as w approaches n. In this sense all despinning timescales are in fact infinite. We therefore define an effective despinning timescale as the time required for despin tidal heating to fall below tidal heating due to orbital eccentricity. For many satellites in the Solar System, including such major moons as Io and Europa, the neglected term in the despinning timescale is in fact the dominant term. For some especially short-period satellites, such as Phobos or Amalthea, the resulting despinning timescales are one to two orders of magnitude longer than those previously accepted.

  19. Flood-inundation maps for Indian Creek and Tomahawk Creek, Johnson County, Kansas, 2014

    USGS Publications Warehouse

    Peters, Arin J.; Studley, Seth E.

    2016-01-25

    Digital flood-inundation maps for a 6.4-mile upper reach of Indian Creek from College Boulevard to the confluence with Tomahawk Creek, a 3.9-mile reach of Tomahawk Creek from 127th Street to the confluence with Indian Creek, and a 1.9-mile lower reach of Indian Creek from the confluence with Tomahawk Creek to just beyond the Kansas/Missouri border at State Line Road in Johnson County, Kansas, were created by the U.S. Geological Survey in cooperation with the city of Overland Park, Kansas. The flood-inundation maps, which can be accessed through the U.S. Geological Survey Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the U.S. Geological Survey streamgages on Indian Creek at Overland Park, Kansas; Indian Creek at State Line Road, Leawood, Kansas; and Tomahawk Creek near Overland Park, Kansas. Near real time stages at these streamgages may be obtained on the Web from the U.S. Geological Survey National Water Information System at http://waterdata.usgs.gov/nwis or the National Weather Service Advanced Hydrologic Prediction Service at http://water.weather.gov/ahps/, which also forecasts flood hydrographs at these sites.Flood profiles were computed for the stream reaches by means of a one-dimensional step-backwater model. The model was calibrated for each reach by using the most current stage-discharge relations at the streamgages. The hydraulic models were then used to determine 15 water-surface profiles for Indian Creek at Overland Park, Kansas; 17 water-surface profiles for Indian Creek at State Line Road, Leawood, Kansas; and 14 water-surface profiles for Tomahawk Creek near Overland Park, Kansas, for flood stages at 1-foot intervals referenced to the streamgage datum and ranging from bankfull to the next interval above the 0.2-percent annual exceedance probability flood level (500-year recurrence interval). The

  20. L-Lake/Steel Creek data base

    SciTech Connect

    Dicks, A.S.

    1988-10-01

    This report documents the data collected from the L-Lake/Steel Creek Biological Monitoring Program from November 1985 through December 1988. The data base is comprised of information to evaluate the major biotic components of L Lake, Steel Creek, and portions of the Savannah River swamp. Data were collected in lake, stream, and wetlands areas that are potentially affected by the discharge of heated effluents from L-Reactor. Biological data consist of measurements of composition, abundance, distribution, and selected functional attributes of the algae, macrophyte, zooplankton, macroinvertebrate, and fish populations. Water chemistry data consist of measurements of concentration for numerous chemical parameters and other limnological parameters.

  1. VISCOELASTIC MODELS OF TIDALLY HEATED EXOMOONS

    SciTech Connect

    Dobos, Vera; Turner, Edwin L.

    2015-05-01

    Tidal heating of exomoons may play a key role in their habitability, since the elevated temperature can melt the ice on the body even without significant solar radiation. The possibility of life has been intensely studied on solar system moons such as Europa or Enceladus where the surface ice layer covers a tidally heated water ocean. Tidal forces may be even stronger in extrasolar systems, depending on the properties of the moon and its orbit. To study the tidally heated surface temperature of exomoons, we used a viscoelastic model for the first time. This model is more realistic than the widely used, so-called fixed Q models because it takes into account the temperature dependence of the tidal heat flux and the melting of the inner material. Using this model, we introduced the circumplanetary Tidal Temperate Zone (TTZ), which strongly depends on the orbital period of the moon and less on its radius. We compared the results with the fixed Q model and investigated the statistical volume of the TTZ using both models. We have found that the viscoelastic model predicts 2.8 times more exomoons in the TTZ with orbital periods between 0.1 and 3.5 days than the fixed Q model for plausible distributions of physical and orbital parameters. The viscoelastic model provides more promising results in terms of habitability because the inner melting of the body moderates the surface temperature, acting like a thermostat.

  2. Tidal Interactions in Merging White Dwarf Binaries

    NASA Astrophysics Data System (ADS)

    Piro, Anthony L.

    2011-10-01

    The recently discovered system J0651 is the tightest known detached white dwarf (WD) binary. Since it has not yet initiated Roche-lobe overflow, it provides a relatively clean environment for testing our understanding of tidal interactions. I investigate the tidal heating of each WD, parameterized in terms of its tidal Q parameter. Assuming that the heating can be radiated efficiently, the current luminosities are consistent with Q 1 ≈ 7 × 1010 and Q 2 ≈ 2 × 107, for the He and C/O WDs, respectively. Conversely, if the observed luminosities are merely from the cooling of the WDs, these estimated values of Q represent the upper limits. A large Q 1 for the He WD means its spin velocity will be slower than that expected if it was tidally locked, which, since the binary is eclipsing, may be measurable via the Rossiter-McLaughlin effect. After one year, gravitational wave emission shifts the time of eclipses by 5.5 s, but tidal interactions cause the orbit to shrink more rapidly, changing the time by up to an additional 0.3 s after a year. Future eclipse timing measurements may therefore infer the degree of tidal locking.

  3. Viscoelastic Models of Tidally Heated Exomoons

    NASA Astrophysics Data System (ADS)

    Dobos, Vera; Turner, Edwin L.

    2015-05-01

    Tidal heating of exomoons may play a key role in their habitability, since the elevated temperature can melt the ice on the body even without significant solar radiation. The possibility of life has been intensely studied on solar system moons such as Europa or Enceladus where the surface ice layer covers a tidally heated water ocean. Tidal forces may be even stronger in extrasolar systems, depending on the properties of the moon and its orbit. To study the tidally heated surface temperature of exomoons, we used a viscoelastic model for the first time. This model is more realistic than the widely used, so-called fixed Q models because it takes into account the temperature dependence of the tidal heat flux and the melting of the inner material. Using this model, we introduced the circumplanetary Tidal Temperate Zone (TTZ), which strongly depends on the orbital period of the moon and less on its radius. We compared the results with the fixed Q model and investigated the statistical volume of the TTZ using both models. We have found that the viscoelastic model predicts 2.8 times more exomoons in the TTZ with orbital periods between 0.1 and 3.5 days than the fixed Q model for plausible distributions of physical and orbital parameters. The viscoelastic model provides more promising results in terms of habitability because the inner melting of the body moderates the surface temperature, acting like a thermostat.

  4. Half Moon Cove Tidal Project. Feasibility report

    SciTech Connect

    Not Available

    1980-11-01

    The proposed Half Moon Cove Tidal Power Project would be located in a small cove in the northern part of Cobscook Bay in the vicinity of Eastport, Maine. The project would be the first tidal electric power generating plant in the United States of America. The basin impounded by the barrier when full will approximate 1.2 square miles. The average tidal range at Eastport is 18.2 feet. The maximum spring tidal range will be 26.2 feet and the neap tidal range 12.8 feet. The project will be of the single pool-type single effect in which generation takes place on the ebb tide only. Utilizing an average mean tidal range of 18.2 feet the mode of operation enables generation for approximately ten and one-half (10-1/2) hours per day or slightly in excess of five (5) hours per tide. The installed capacity will be 12 MW utilizing 2 to 6 MW units. An axial flow, or Bulb type of turbine was selected for this study.

  5. TIDAL INTERACTIONS IN MERGING WHITE DWARF BINARIES

    SciTech Connect

    Piro, Anthony L.

    2011-10-20

    The recently discovered system J0651 is the tightest known detached white dwarf (WD) binary. Since it has not yet initiated Roche-lobe overflow, it provides a relatively clean environment for testing our understanding of tidal interactions. I investigate the tidal heating of each WD, parameterized in terms of its tidal Q parameter. Assuming that the heating can be radiated efficiently, the current luminosities are consistent with Q {sub 1} {approx} 7 x 10{sup 10} and Q {sub 2} {approx} 2 x 10{sup 7}, for the He and C/O WDs, respectively. Conversely, if the observed luminosities are merely from the cooling of the WDs, these estimated values of Q represent the upper limits. A large Q {sub 1} for the He WD means its spin velocity will be slower than that expected if it was tidally locked, which, since the binary is eclipsing, may be measurable via the Rossiter-McLaughlin effect. After one year, gravitational wave emission shifts the time of eclipses by 5.5 s, but tidal interactions cause the orbit to shrink more rapidly, changing the time by up to an additional 0.3 s after a year. Future eclipse timing measurements may therefore infer the degree of tidal locking.

  6. Fitting orbits to tidal streams

    NASA Astrophysics Data System (ADS)

    Binney, James

    2008-05-01

    Recent years have seen the discovery of many tidal streams through the Galaxy. Relatively straightforward observations of a stream allow one to deduce three phase-space coordinates of an orbit. An algorithm is presented that reconstructs the missing phase-space coordinates from these data. The reconstruction starts from assumed values of the Galactic potential and a distance to one point on the orbit, but with noise-free data the condition that energy be conserved on the orbit enables one to reject incorrect assumptions. The performance of the algorithm is investigated when errors are added to the input data that are comparable to those in published data for the streams of Pal 5. It is found that the algorithm returns distances and proper motions that are accurate to of the order of 1 per cent, and enables one to reject quite resonable but incorrect trial potentials. In practical applications, it will be important to minimize errors in the imput data, and there is considerable scope for doing this.

  7. MINARETS WILDERNESS AND ADJACENT AREAS, CALIFORNIA.

    USGS Publications Warehouse

    Huber, N. King; Thurber, Horace K.

    1984-01-01

    A mineral survey of the Minarets Wilderness and adjacent areas in the central Sierra Nevada, California was conducted. The results of the survey indicate that the study area has a substantiated resource potential for small deposits of copper, silver, zinc, lead, and iron, and a probable mineral-resource potential for molybdenum. No energy-resource potential was identified in the study.

  8. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES CARRIAGE OF BULK SOLID MATERIALS... transporting a material that Table 148.10 of this part associates with a reference to this section, the following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  9. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES CARRIAGE OF BULK SOLID MATERIALS... transporting a material that Table 148.10 of this part associates with a reference to this section, the following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  10. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES CARRIAGE OF BULK SOLID MATERIALS... transporting a material that Table 148.10 of this part associates with a reference to this section, the following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  11. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES CARRIAGE OF BULK SOLID MATERIALS... transporting a material that Table 148.10 of this part associates with a reference to this section, the following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  12. Long-Term Sediment Dynamics in a Tidal Salt Marsh, North Inlet, South Carolina

    NASA Astrophysics Data System (ADS)

    Murphy, S.; Voulgaris, G.

    2001-05-01

    system coincides with spring tides while export occurs during neap tidal conditions. Rainfall increases sediment concentration in the channels and appears to be associated with periods of sediment redistribution within the marsh. The impact of river discharge on suspended sediment concentrations affects the marsh over longer time intervals with years of low discharge into adjacent Winyah Bay coinciding with periods of low suspended sediment concentrations. Water discharge through each channel will be estimated using harmonic analysis of tidal current records collected over a 30-day period in order to resolve spring-neap variations in tidal velocity. The coupling of mean suspended sediment concentration and water discharge of the same phase will later be used to produce a long-term sediment budget for the marsh basin.

  13. 78 FR 28897 - Lost Creek ISR, LLC, Lost Creek Uranium In-Situ Recovery Project; Sweetwater County, Wyoming

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-16

    ... From the Federal Register Online via the Government Publishing Office NUCLEAR REGULATORY COMMISSION Lost Creek ISR, LLC, Lost Creek Uranium In-Situ Recovery Project; Sweetwater County, Wyoming AGENCY: Nuclear Regulatory Commission. ACTION: Environmental assessment and finding of no...

  14. 78 FR 938 - Burton Creek Hydro Inc., Sollos Energy, LLC'

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-07

    ... Energy Regulatory Commission Burton Creek Hydro Inc., Sollos Energy, LLC' Notice of Transfer of Exemption 1. By letter filed December 19, 2012, Burton Creek Hydro Inc. informed the Commission that its exemption from licensing for the Burton Creek Hydro Project, FERC No. 7577, originally issued September...

  15. 75 FR 8036 - Monitor-Hot Creek Rangeland Project

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... Forest Service Monitor-Hot Creek Rangeland Project AGENCY: Forest Service, USDA. ACTION: Notice of intent... continued livestock grazing ] within the Monitor-Hot Creek Rangeland Project area. The analysis will... conditions within the Monitor-Hot Creek Rangeland Project area towards desired conditions. The project...

  16. View looking Eastnortheast at French Creek trestle, which appears at ...

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

    View looking Eastnortheast at French Creek trestle, which appears at left center of frame. Bridge in foreground is west entrance to abandoned Phoenix iron works. - Pennsylvania Railroad, French Creek Trestle, Spanning French Creek, north of Paradise Street, Phoenixville, Chester County, PA

  17. 76 FR 35349 - Drawbridge Operation Regulations; Cheesequake Creek, Morgan, NJ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-17

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Cheesequake Creek, Morgan, NJ AGENCY... the Route 35 Bridge, mile 0.0, across Cheesequake Creek at Morgan, New Jersey. The deviation is... Bridge, across Cheesequake Creek, mile 0.0, at Morgan, New Jersey, has a vertical clearance in the...

  18. 76 FR 43123 - Drawbridge Operation Regulations; Cheesequake Creek, Morgan, NJ

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-20

    ... SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Cheesequake Creek, Morgan, NJ AGENCY... the Route 35 Bridge, mile 0.0, across Cheesequake Creek at Morgan, New Jersey. The deviation is...: The Route 35 Bridge, across Cheesequake Creek, mile 0.0, at Morgan, New Jersey, has a...

  19. 76 FR 9225 - Drawbridge Operation Regulation; Curtis Creek, Baltimore, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-17

    ... Regulations; Curtis Creek, Baltimore, MD'' in the Federal Register (74 FR 50707). The temporary deviation... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulation; Curtis Creek, Baltimore... changing the drawbridge operation regulations of the Pennington Avenue Bridge, across Curtis Creek, mile...

  20. 75 FR 1705 - Drawbridge Operation Regulations; Curtis Creek, Baltimore, MD

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-13

    ... SECURITY Coast Guard 33 CFR Part 117 RIN 1625-AA09 Drawbridge Operation Regulations; Curtis Creek... operation of the I695 Bridge across Curtis Creek, mile 0.9, at Baltimore, MD. The deviation is necessary to... section of Curtis Creek and the bridge will not be able to open in the event of an emergency. Coast...

  1. Detail view of the Ten Mile Creek Bridge joint between ...

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

    Detail view of the Ten Mile Creek Bridge joint between the tied arch span and the approach span, view looking east at southwest corner of bridge. - Ten Mile Creek Bridge, Spanning Ten Mile Creek on Oregon Coast Highway, Yachats, Lincoln County, OR

  2. 33 CFR 110.72 - Blackhole Creek, Md.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Blackhole Creek, Md. 110.72... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.72 Blackhole Creek, Md. The waters on the west side of Blackhole Creek, a tributary of Magothy River, southwest of a line bearing 310°30′ from the most...

  3. 33 CFR 110.72 - Blackhole Creek, Md.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Blackhole Creek, Md. 110.72... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.72 Blackhole Creek, Md. The waters on the west side of Blackhole Creek, a tributary of Magothy River, southwest of a line bearing 310°30′ from the most...

  4. 33 CFR 110.72 - Blackhole Creek, Md.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Blackhole Creek, Md. 110.72... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.72 Blackhole Creek, Md. The waters on the west side of Blackhole Creek, a tributary of Magothy River, southwest of a line bearing 310°30′ from the most...

  5. 33 CFR 110.72 - Blackhole Creek, Md.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Blackhole Creek, Md. 110.72... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.72 Blackhole Creek, Md. The waters on the west side of Blackhole Creek, a tributary of Magothy River, southwest of a line bearing 310°30′ from the most...

  6. Topographic view of the North Fork Butter Creek Bridge (located ...

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

    Topographic view of the North Fork Butter Creek Bridge (located center of frame), view looking west - North Fork Butter Creek Bridge, Spanning North Fork Butter Creek Bridge at Milepost 76.63 on Heppner Highway (Oregon Route 74), Pilot Rock, Umatilla County, OR

  7. 20. DISTANT HELICOPTER VIEW TO SOUTHEAST UP LITTLE ROCK CREEK ...

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

    20. DISTANT HELICOPTER VIEW TO SOUTHEAST UP LITTLE ROCK CREEK CANYON, WITH DAM AND RESERVOIR AT RIGHT CENTER. PALMDALE-LITTLEROCK DITCH, MARKED BY DENSE VEGETATION, CROSSES ROAD AT LOWER CENTER - Little Rock Creek Dam, Little Rock Creek, Littlerock, Los Angeles County, CA

  8. 33 CFR 110.72 - Blackhole Creek, Md.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Blackhole Creek, Md. 110.72... ANCHORAGE REGULATIONS Special Anchorage Areas § 110.72 Blackhole Creek, Md. The waters on the west side of Blackhole Creek, a tributary of Magothy River, southwest of a line bearing 310°30′ from the most...

  9. Changes in surfzone morphodynamics driven by multi-decadel contraction of a large ebb-tidal delta

    USGS Publications Warehouse

    Hansen, Jeff E.; Elias, Edwin; Barnard, Patrick L.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

    2013-01-01

    The impact of multi-decadal, large-scale deflation (76 million m3 of sediment loss) and contraction (~ 1 km) of a 150 km2 ebb-tidal delta on hydrodynamics and sediment transport at adjacent Ocean Beach in San Francisco, CA (USA), is examined using a coupled wave and circulation model. The model is forced with representative wave and tidal conditions using recent (2005) and historic (1956) ebb-tidal delta bathymetry data sets. Comparison of the simulations indicates that along north/south trending Ocean Beach the contraction and deflation of the ebb-tidal delta have resulted in significant differences in the flow and sediment dynamics. Between 1956 and 2005 the transverse bar (the shallow attachment point of the ebb-tidal delta to the shoreline) migrated northward ~ 1 km toward the inlet while a persistent alongshore flow and transport divergence point migrated south by ~ 500 m such that these features now overlap. A reduction in tidal prism and sediment supply over the last century has resulted in a net decrease in offshore tidal current-generated sediment transport at the mouth of San Francisco Bay, and a relative increase in onshore-directed wave-driven transport toward the inlet, accounting for the observed contraction of the ebb-tidal delta. Alongshore migration of the transverse bar and alongshore flow divergence have resulted in an increasing proportion of onshore migrating sediment from the ebb-tidal delta to be transported north along the beach in 2005 versus south in 1956. The northerly migrating sediment is then trapped by Pt. Lobos, a rocky headland at the northern extreme of the beach, consistent with the observed shoreline accretion in this area. Conversely, alongshore migration of the transverse bar and divergence point has decreased the sediment supply to southern Ocean Beach, consistent with the observed erosion of the shoreline in this area. This study illustrates the utility of applying a high-resolution coupled circulation-wave model for

  10. Seabed drifter movement in San Diego Bay and adjacent waters

    NASA Astrophysics Data System (ADS)

    Hammond, Robert R.; Wallace, William J.

    1982-06-01

    The seabed drifter has been used successfully to provide valuable information in many estuarine and open sea environments. It was therefore selected for use in the San Diego area. Five hundred drifters were released in San Diego Bay and adjacent ocean waters to delineate bottom flow patterns. Four significant bottom drift regimes are differentiated: off-coastal, main bay channel, open and semi-enclosed docking basins. Mean residual bottom drift ranged between 0·17km day -1 off the coast to essentially zero in the docking basins. Off-coast drifter results (31% recovery) showed a persistent northmoving bottom current with shallow near-coast drift distances between 4 and 25 km. This nearshore north moving bottom current appears to cause a net bottom water inflow into the main San Diego Bay channel (44% recovery). In the open bay a reverse trend was observed from the 16% of the drifters recovered. At the head of the estuary, evaporative densification is believed to occur, with the heavier water sinking and moving outward, towards the estuary mouth, resulting in an area of opposing bottom water currents. In this area San Diego Gas and Electric power plant takes in an average 150 million gallons of cooling water daily which, discharged as warm surface water, is suggested as the surface divergence mode required to reconcile the observed flow. With the three San Diego Bay electric power plants utilizing more than 5% of the maximum tidal prism for cooling purposes, this flow may play a major role in the overall bay circulation and requires quantitative investigation.

  11. Measurements and consequences of retention in a side embayment in a tidal river

    NASA Astrophysics Data System (ADS)

    Carr, M. L.; Rehmann, C. R.; Stoeckel, J. A.; Padilla, D. K.; Schneider, D. W.

    2004-08-01

    Embayments and tidal flow can affect the population structure of organisms, such as the zebra mussel ( Dreissena polymorpha), that have a planktonic larval phase. To examine the potential retention of larvae in embayments in tidal rivers and predict the effect of embayments on transport in the river, a field experiment was conducted and a quasi one-dimensional model was developed. Dye was injected into North Tivoli Bay, which is adjacent to the tidal portion of the Hudson River, at the start of a flood tide, and measurements of concentration, stage, and velocity over 1.5 tidal cycles were used in a mass balance to estimate the fraction of dye mass in the bay. After the first ebb, 27% of the dye remained in the bay, and during the following flood the dye that returned increased the mass in the bay to 42% of the injection mass. The field measurements were used to calibrate a quasi one-dimensional model consisting of a series of well-mixed cells with a well-mixed bay adjacent to one of the river cells. The model predicts that a small fraction of larvae would be retained in the bay by the time larvae were competent to settle, but self-recruitment may be possible due to large numbers of larvae. If enough larvae are initially produced, recruitment in the river near the spawning site is possible because the small net southward flow typical of the spawning season provides little downstream transport of the peak of the dye cloud.

  12. Aerial and tidal transport of mosquito control pesticides into the Florida Keys National Marine Sanctuary.

    PubMed

    Pierce, R H; Henry, M S; Blum, T C; Mueller, E M

    2005-05-01

    This project was undertaken as the initial monitoring program to determine if mosquito adulticides applied along the Florida Keys cause adverse ecological effects in the Florida Keys National Marine Sanctuary (FKNMS). The study monitored the distribution and persistence of two mosquito adulticides, permethrin and dibrom (naled), during three separate routine applications by the Florida Keys Mosquito Control District. The approach was to determine if toxic concentrations of the pesticides entered the FKNMS by aerial drift or tidal transport. The amount of pesticide entering the FKNMS by way of aerial drift was monitored by collection on glass fiber filter pads, set on floats in a grid pattern on either side of the FKNMS. Permethrin was recovered from filter pads on the leeward side for each of the three applications, ranging from 0.5 to 50.1 microg/m(2) throughout the study. Tidal current transport was monitored by collection of surface and subsurface water samples at each grid site. Tidal transport of naled and dichlorvos (naled degradation product) was apparent in the adjacent waters of the FKNMS. These compounds were detected in subsurface, offshore water at 0.1 to 0.6 microg/1, 14 hr after application. Permethrin was not detected in offshore water samples; however, concentrations ranging from 5.1 to 9.4 microg/l were found in surface water from the canal system adjacent to the application route. Comparison of the observed environmental concentrations with toxicity data (permethrin LC-50, 96 hr for Mysidopsis bahia = 0.02 microg/l) indicated a potential hazard to marine invertebrates in the canals with possible tidal transport to other areas. PMID:17465151

  13. Reservoir heterogeneity in Carter Sandstone, North Blowhorn Creek oil unit and vicinity, Black Warrior Basin, Alabama

    SciTech Connect

    Kugler, R.L.; Pashin, J.C.

    1992-05-01

    This report presents accomplishments made in completing Task 3 of this project which involves development of criteria for recognizing reservoir heterogeneity in the Black Warrior basin. The report focuses on characterization of the Upper Mississippian Carter sandstone reservoir in North Blowhorn Creek and adjacent oil units in Lamar County, Alabama. This oil unit has produced more than 60 percent of total oil extracted from the Black Warrior basin of Alabama. The Carter sandstone in North Blowhorn Creek oil unit is typical of the most productive Carter oil reservoirs in the Black Warrior basin of Alabama. The first part of the report synthesizes data derived from geophysical well logs and cores from North Blowhorn Creek oil unit to develop a depositional model for the Carter sandstone reservoir. The second part of the report describes the detrital and diagenetic character of Carter sandstone utilizing data from petrographic and scanning electron microscopes and the electron microprobe. The third part synthesizes porosity and pore-throat-size-distribution data determined by high-pressure mercury porosimetry and commercial core analyses with results of the sedimentologic and petrographic studies. The final section of the report discusses reservoir heterogeneity within the context of the five-fold classification of Moore and Kugler (1990).

  14. Outline of the water resources of the Status Creek basin, Yakima Indian Reservation, Washington

    USGS Publications Warehouse

    Molenaar, Dee

    1976-01-01

    On the Yakima Indian Reservation, Washington, only about 5 percent of the Satus Creek basin--in the relatively flat eastern lowland adjacent to and including part of the Yakima River lowland--is agriculturally developed, mostly through irrigation. Because the basin 's streams do not contain adequate water for irrigation, most irrigation is by canal diversion from the adjoining Toppenish Creek basin. Irrigation application of as much as 9.25 acre-feet per acre per year, combined with the presence of poorly drained silt and clay layers in this area, and the natural upward discharge of ground water from deeper aquifers (water-bearing layers), has contributed to a waterlogging problem, which has affected about 10,500 acres, or about 25 percent of the irrigated area. In the upland of the basin, a large average annual base flow of about 30 cubic feet per second in Logy Creek indicates the presence of a potentially highly productive aquifer in young (shallow) basalt lavas underlying the higher western parts of the upland. This aquifer may provide a reservoir from which streamflow may be augmented by ground-water pumping or, alternatively, it may be used as a source of ground water for irrigation of upland areas directly. (Woodard-USGS)

  15. Evolution and stability of tidal river bifurcations

    NASA Astrophysics Data System (ADS)

    Kleinhans, M. G.

    2011-12-01

    At bifurcations, water and sediment are partitioned, so that long-term evolution of fluvial and deltaic channels is determined by the bifurcation stability. Recent work in fluvial environments showed that bifurcations are commonly unstable so that avulsion results. For tidal rivers it could be argued that the discharge fluctuation enhances transport so that it simply closes of faster than in steady flow, but it could also be argued that tidal phase differences between the bifurcates cause a residual flow that counteracts the closing trend and keeps both bifurcates open. A physics-based numerical model (Delft3D) was used to model fixed-bank fork-shaped bifurcations with and without tides, and with short and long length relative to tidal wavelength. In all cases the bifurcations remained as unstable as without tides and ended invariably in avulsion. Tidal bifurcations unbalanced more rapidly than fluvial bifurcations, because of the increased ebb current and nonlinearity of sediment transport. On the other hand, discharge partitioning at the final bifurcation was much less asymmetrical with tides than without. Tidal wave deformation and production of higher harmonics in the longer channels affected sediment partitioning in the unstable phase but seems to have no effect on equilibrium morphology. Significant phase differences between the bifurcates caused a tidal floss effect, which scoured the bifurcation. In conclusion, symmetrical bifurcations affected by tides are unstable, but their final equilibrium is more symmetrical than without tides unless bifurcates have significant tidal phase differences. Furthermore I modelled growing deltas with self-formed distributary channels with and without cohesive sediment and with and without tides. Here, tides cause the flow to be more focussed in fewer and larger channels, whilst the few bifurcations are relatively stable. Combined fluvial discharge and tidal ebb flow in the channels transports more sediment than in fluvial

  16. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  17. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  18. 33 CFR 334.240 - Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Potomac River, Mattawoman Creek and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md. 334... and Chicamuxen Creek; U.S. Naval Surface Weapons Center, Indian Head Division, Indian Head, Md....

  19. 78 FR 20146 - Lost Creek ISR, LLC, Lost Creek Uranium In-Situ Recovery Project, Sweetwater County, Wyoming

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ... COMMISSION Lost Creek ISR, LLC, Lost Creek Uranium In-Situ Recovery Project, Sweetwater County, Wyoming... considering an amendment to Source Materials License SUA-1598 for continued uranium production operations and in-situ recovery (ISR) of uranium at the Lost Creek Project in Sweetwater County, Wyoming....

  20. Description and User Manual for a Web-Based Interface to a Transit-Loss Accounting Program for Monument and Fountain Creeks, El Paso and Pueblo Counties, Colorado

    USGS Publications Warehouse

    Kuhn, Gerhard; Krammes, Gary S.; Beal, Vivian J.

    2007-01-01

    -loss computations for a variable number of reusable return flows discharged into Monument Creek at selected locations; (3) enable diversion of all or a part of a reusable return flow at any selected node for purposes of storage in off-stream reservoirs or other similar types of reusable water management; (4) and provide flexibility in the accounting program to change the number of return-flow entities, the locations at which the return flows discharge into Monument or Fountain Creeks, or the locations to which the return flows are delivered. The primary component of the Web-based interface is a data-entry form that displays data stored in the accounting program input file; the data-entry form allows for entry and modification of new data, which then is rewritten to the input file. When the data-entry form is displayed, up-to-date discharge data for each station are automatically computed and entered on the data-entry form. Data for native return flows, reusable return flows, reusable return flow diversions, and native diversions also are entered automatically or manually, if needed. In computing the estimated quantities of reusable return flow and the associated transit losses, the accounting program uses two sets of computations. The first set of computations is made between any two adjacent streamflow-gaging stations (termed 'stream-segment loop'); the primary purpose of the stream-segment loop is to estimate the loss or gain in native discharge between the two adjacent streamflow-gaging stations. The second set of computations is made between any two adjacent nodes (termed 'subreach loop'); the actual transit-loss computations are made in the subreach loop, using the result from the stream-segment loop. The stream-segment loop is completed for a stream segment, and then the subreach loop is completed for each subreach within the segment. When the subreach loop is completed for all subreaches within a stream segment, the stream-segment loop is initiated for the ne